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-rw-r--r--fs/compat.c5
-rw-r--r--fs/exec.c4
-rw-r--r--fs/file_table.c9
-rw-r--r--fs/inode.c8
-rw-r--r--fs/namei.c2
-rw-r--r--fs/namespace.c5
-rw-r--r--fs/nfsd/vfs.c4
-rw-r--r--fs/notify/Kconfig1
-rw-r--r--fs/notify/Makefile4
-rw-r--r--fs/notify/dnotify/dnotify.c213
-rw-r--r--fs/notify/fanotify/Kconfig26
-rw-r--r--fs/notify/fanotify/Makefile1
-rw-r--r--fs/notify/fanotify/fanotify.c212
-rw-r--r--fs/notify/fanotify/fanotify_user.c760
-rw-r--r--fs/notify/fsnotify.c201
-rw-r--r--fs/notify/fsnotify.h27
-rw-r--r--fs/notify/group.c182
-rw-r--r--fs/notify/inode_mark.c331
-rw-r--r--fs/notify/inotify/Kconfig15
-rw-r--r--fs/notify/inotify/Makefile1
-rw-r--r--fs/notify/inotify/inotify.c872
-rw-r--r--fs/notify/inotify/inotify.h7
-rw-r--r--fs/notify/inotify/inotify_fsnotify.c151
-rw-r--r--fs/notify/inotify/inotify_user.c369
-rw-r--r--fs/notify/mark.c371
-rw-r--r--fs/notify/notification.c236
-rw-r--r--fs/notify/vfsmount_mark.c187
-rw-r--r--fs/open.c3
-rw-r--r--fs/read_write.c8
29 files changed, 2468 insertions, 1747 deletions
diff --git a/fs/compat.c b/fs/compat.c
index 3e57e8162a39..e6d5d70cf3cf 100644
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -1193,11 +1193,10 @@ out:
if (iov != iovstack)
kfree(iov);
if ((ret + (type == READ)) > 0) {
- struct dentry *dentry = file->f_path.dentry;
if (type == READ)
- fsnotify_access(dentry);
+ fsnotify_access(file);
else
- fsnotify_modify(dentry);
+ fsnotify_modify(file);
}
return ret;
}
diff --git a/fs/exec.c b/fs/exec.c
index dab85ecad686..7761837e4500 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -128,7 +128,7 @@ SYSCALL_DEFINE1(uselib, const char __user *, library)
if (file->f_path.mnt->mnt_flags & MNT_NOEXEC)
goto exit;
- fsnotify_open(file->f_path.dentry);
+ fsnotify_open(file);
error = -ENOEXEC;
if(file->f_op) {
@@ -683,7 +683,7 @@ struct file *open_exec(const char *name)
if (file->f_path.mnt->mnt_flags & MNT_NOEXEC)
goto exit;
- fsnotify_open(file->f_path.dentry);
+ fsnotify_open(file);
err = deny_write_access(file);
if (err)
diff --git a/fs/file_table.c b/fs/file_table.c
index 5c7d10ead4ad..b8a0bb63cbd7 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -230,6 +230,15 @@ static void __fput(struct file *file)
might_sleep();
fsnotify_close(file);
+
+ /*
+ * fsnotify_create_event may have taken one or more references on this
+ * file. If it did so it left one reference for us to drop to make sure
+ * its calls to fput could not prematurely destroy the file.
+ */
+ if (atomic_long_read(&file->f_count))
+ return fput(file);
+
/*
* The function eventpoll_release() should be the first called
* in the file cleanup chain.
diff --git a/fs/inode.c b/fs/inode.c
index 2575244640a8..86464332e590 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -20,7 +20,6 @@
#include <linux/pagemap.h>
#include <linux/cdev.h>
#include <linux/bootmem.h>
-#include <linux/inotify.h>
#include <linux/fsnotify.h>
#include <linux/mount.h>
#include <linux/async.h>
@@ -264,12 +263,8 @@ void inode_init_once(struct inode *inode)
INIT_RAW_PRIO_TREE_ROOT(&inode->i_data.i_mmap);
INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear);
i_size_ordered_init(inode);
-#ifdef CONFIG_INOTIFY
- INIT_LIST_HEAD(&inode->inotify_watches);
- mutex_init(&inode->inotify_mutex);
-#endif
#ifdef CONFIG_FSNOTIFY
- INIT_HLIST_HEAD(&inode->i_fsnotify_mark_entries);
+ INIT_HLIST_HEAD(&inode->i_fsnotify_marks);
#endif
}
EXPORT_SYMBOL(inode_init_once);
@@ -413,7 +408,6 @@ int invalidate_inodes(struct super_block *sb)
down_write(&iprune_sem);
spin_lock(&inode_lock);
- inotify_unmount_inodes(&sb->s_inodes);
fsnotify_unmount_inodes(&sb->s_inodes);
busy = invalidate_list(&sb->s_inodes, &throw_away);
spin_unlock(&inode_lock);
diff --git a/fs/namei.c b/fs/namei.c
index 42d2d28fb827..13ff4abdbdca 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2633,7 +2633,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
{
int error;
int is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
- const char *old_name;
+ const unsigned char *old_name;
if (old_dentry->d_inode == new_dentry->d_inode)
return 0;
diff --git a/fs/namespace.c b/fs/namespace.c
index 32dcd24bbc9a..66c4f7e781cb 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -29,6 +29,7 @@
#include <linux/log2.h>
#include <linux/idr.h>
#include <linux/fs_struct.h>
+#include <linux/fsnotify.h>
#include <asm/uaccess.h>
#include <asm/unistd.h>
#include "pnode.h"
@@ -150,6 +151,9 @@ struct vfsmount *alloc_vfsmnt(const char *name)
INIT_LIST_HEAD(&mnt->mnt_share);
INIT_LIST_HEAD(&mnt->mnt_slave_list);
INIT_LIST_HEAD(&mnt->mnt_slave);
+#ifdef CONFIG_FSNOTIFY
+ INIT_HLIST_HEAD(&mnt->mnt_fsnotify_marks);
+#endif
#ifdef CONFIG_SMP
mnt->mnt_writers = alloc_percpu(int);
if (!mnt->mnt_writers)
@@ -610,6 +614,7 @@ static inline void __mntput(struct vfsmount *mnt)
* provides barriers, so count_mnt_writers() below is safe. AV
*/
WARN_ON(count_mnt_writers(mnt));
+ fsnotify_vfsmount_delete(mnt);
dput(mnt->mnt_root);
free_vfsmnt(mnt);
deactivate_super(sb);
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 8812f6b93969..96360a83cb91 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -934,7 +934,7 @@ nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
nfsdstats.io_read += host_err;
*count = host_err;
err = 0;
- fsnotify_access(file->f_path.dentry);
+ fsnotify_access(file);
} else
err = nfserrno(host_err);
out:
@@ -1045,7 +1045,7 @@ nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
goto out_nfserr;
*cnt = host_err;
nfsdstats.io_write += host_err;
- fsnotify_modify(file->f_path.dentry);
+ fsnotify_modify(file);
/* clear setuid/setgid flag after write */
if (inode->i_mode & (S_ISUID | S_ISGID))
diff --git a/fs/notify/Kconfig b/fs/notify/Kconfig
index dffbb0911d02..22c629eedd82 100644
--- a/fs/notify/Kconfig
+++ b/fs/notify/Kconfig
@@ -3,3 +3,4 @@ config FSNOTIFY
source "fs/notify/dnotify/Kconfig"
source "fs/notify/inotify/Kconfig"
+source "fs/notify/fanotify/Kconfig"
diff --git a/fs/notify/Makefile b/fs/notify/Makefile
index 0922cc826c46..ae5f33a6d868 100644
--- a/fs/notify/Makefile
+++ b/fs/notify/Makefile
@@ -1,4 +1,6 @@
-obj-$(CONFIG_FSNOTIFY) += fsnotify.o notification.o group.o inode_mark.o
+obj-$(CONFIG_FSNOTIFY) += fsnotify.o notification.o group.o inode_mark.o \
+ mark.o vfsmount_mark.o
obj-y += dnotify/
obj-y += inotify/
+obj-y += fanotify/
diff --git a/fs/notify/dnotify/dnotify.c b/fs/notify/dnotify/dnotify.c
index 7e54e52964dd..3344bdd5506e 100644
--- a/fs/notify/dnotify/dnotify.c
+++ b/fs/notify/dnotify/dnotify.c
@@ -29,17 +29,17 @@
int dir_notify_enable __read_mostly = 1;
static struct kmem_cache *dnotify_struct_cache __read_mostly;
-static struct kmem_cache *dnotify_mark_entry_cache __read_mostly;
+static struct kmem_cache *dnotify_mark_cache __read_mostly;
static struct fsnotify_group *dnotify_group __read_mostly;
static DEFINE_MUTEX(dnotify_mark_mutex);
/*
- * dnotify will attach one of these to each inode (i_fsnotify_mark_entries) which
+ * dnotify will attach one of these to each inode (i_fsnotify_marks) which
* is being watched by dnotify. If multiple userspace applications are watching
* the same directory with dnotify their information is chained in dn
*/
-struct dnotify_mark_entry {
- struct fsnotify_mark_entry fsn_entry;
+struct dnotify_mark {
+ struct fsnotify_mark fsn_mark;
struct dnotify_struct *dn;
};
@@ -51,27 +51,27 @@ struct dnotify_mark_entry {
* it calls the fsnotify function so it can update the set of all events relevant
* to this inode.
*/
-static void dnotify_recalc_inode_mask(struct fsnotify_mark_entry *entry)
+static void dnotify_recalc_inode_mask(struct fsnotify_mark *fsn_mark)
{
__u32 new_mask, old_mask;
struct dnotify_struct *dn;
- struct dnotify_mark_entry *dnentry = container_of(entry,
- struct dnotify_mark_entry,
- fsn_entry);
+ struct dnotify_mark *dn_mark = container_of(fsn_mark,
+ struct dnotify_mark,
+ fsn_mark);
- assert_spin_locked(&entry->lock);
+ assert_spin_locked(&fsn_mark->lock);
- old_mask = entry->mask;
+ old_mask = fsn_mark->mask;
new_mask = 0;
- for (dn = dnentry->dn; dn != NULL; dn = dn->dn_next)
+ for (dn = dn_mark->dn; dn != NULL; dn = dn->dn_next)
new_mask |= (dn->dn_mask & ~FS_DN_MULTISHOT);
- entry->mask = new_mask;
+ fsnotify_set_mark_mask_locked(fsn_mark, new_mask);
if (old_mask == new_mask)
return;
- if (entry->inode)
- fsnotify_recalc_inode_mask(entry->inode);
+ if (fsn_mark->i.inode)
+ fsnotify_recalc_inode_mask(fsn_mark->i.inode);
}
/*
@@ -83,29 +83,25 @@ static void dnotify_recalc_inode_mask(struct fsnotify_mark_entry *entry)
* events.
*/
static int dnotify_handle_event(struct fsnotify_group *group,
+ struct fsnotify_mark *inode_mark,
+ struct fsnotify_mark *vfsmount_mark,
struct fsnotify_event *event)
{
- struct fsnotify_mark_entry *entry = NULL;
- struct dnotify_mark_entry *dnentry;
+ struct dnotify_mark *dn_mark;
struct inode *to_tell;
struct dnotify_struct *dn;
struct dnotify_struct **prev;
struct fown_struct *fown;
__u32 test_mask = event->mask & ~FS_EVENT_ON_CHILD;
- to_tell = event->to_tell;
+ BUG_ON(vfsmount_mark);
- spin_lock(&to_tell->i_lock);
- entry = fsnotify_find_mark_entry(group, to_tell);
- spin_unlock(&to_tell->i_lock);
+ to_tell = event->to_tell;
- /* unlikely since we alreay passed dnotify_should_send_event() */
- if (unlikely(!entry))
- return 0;
- dnentry = container_of(entry, struct dnotify_mark_entry, fsn_entry);
+ dn_mark = container_of(inode_mark, struct dnotify_mark, fsn_mark);
- spin_lock(&entry->lock);
- prev = &dnentry->dn;
+ spin_lock(&inode_mark->lock);
+ prev = &dn_mark->dn;
while ((dn = *prev) != NULL) {
if ((dn->dn_mask & test_mask) == 0) {
prev = &dn->dn_next;
@@ -118,12 +114,11 @@ static int dnotify_handle_event(struct fsnotify_group *group,
else {
*prev = dn->dn_next;
kmem_cache_free(dnotify_struct_cache, dn);
- dnotify_recalc_inode_mask(entry);
+ dnotify_recalc_inode_mask(inode_mark);
}
}
- spin_unlock(&entry->lock);
- fsnotify_put_mark(entry);
+ spin_unlock(&inode_mark->lock);
return 0;
}
@@ -133,44 +128,27 @@ static int dnotify_handle_event(struct fsnotify_group *group,
* userspace notification for that pair.
*/
static bool dnotify_should_send_event(struct fsnotify_group *group,
- struct inode *inode, __u32 mask)
+ struct inode *inode,
+ struct fsnotify_mark *inode_mark,
+ struct fsnotify_mark *vfsmount_mark,
+ __u32 mask, void *data, int data_type)
{
- struct fsnotify_mark_entry *entry;
- bool send;
-
- /* !dir_notify_enable should never get here, don't waste time checking
- if (!dir_notify_enable)
- return 0; */
-
/* not a dir, dnotify doesn't care */
if (!S_ISDIR(inode->i_mode))
return false;
- spin_lock(&inode->i_lock);
- entry = fsnotify_find_mark_entry(group, inode);
- spin_unlock(&inode->i_lock);
-
- /* no mark means no dnotify watch */
- if (!entry)
- return false;
-
- mask = (mask & ~FS_EVENT_ON_CHILD);
- send = (mask & entry->mask);
-
- fsnotify_put_mark(entry); /* matches fsnotify_find_mark_entry */
-
- return send;
+ return true;
}
-static void dnotify_free_mark(struct fsnotify_mark_entry *entry)
+static void dnotify_free_mark(struct fsnotify_mark *fsn_mark)
{
- struct dnotify_mark_entry *dnentry = container_of(entry,
- struct dnotify_mark_entry,
- fsn_entry);
+ struct dnotify_mark *dn_mark = container_of(fsn_mark,
+ struct dnotify_mark,
+ fsn_mark);
- BUG_ON(dnentry->dn);
+ BUG_ON(dn_mark->dn);
- kmem_cache_free(dnotify_mark_entry_cache, dnentry);
+ kmem_cache_free(dnotify_mark_cache, dn_mark);
}
static struct fsnotify_ops dnotify_fsnotify_ops = {
@@ -183,15 +161,15 @@ static struct fsnotify_ops dnotify_fsnotify_ops = {
/*
* Called every time a file is closed. Looks first for a dnotify mark on the
- * inode. If one is found run all of the ->dn entries attached to that
+ * inode. If one is found run all of the ->dn structures attached to that
* mark for one relevant to this process closing the file and remove that
* dnotify_struct. If that was the last dnotify_struct also remove the
- * fsnotify_mark_entry.
+ * fsnotify_mark.
*/
void dnotify_flush(struct file *filp, fl_owner_t id)
{
- struct fsnotify_mark_entry *entry;
- struct dnotify_mark_entry *dnentry;
+ struct fsnotify_mark *fsn_mark;
+ struct dnotify_mark *dn_mark;
struct dnotify_struct *dn;
struct dnotify_struct **prev;
struct inode *inode;
@@ -200,38 +178,34 @@ void dnotify_flush(struct file *filp, fl_owner_t id)
if (!S_ISDIR(inode->i_mode))
return;
- spin_lock(&inode->i_lock);
- entry = fsnotify_find_mark_entry(dnotify_group, inode);
- spin_unlock(&inode->i_lock);
- if (!entry)
+ fsn_mark = fsnotify_find_inode_mark(dnotify_group, inode);
+ if (!fsn_mark)
return;
- dnentry = container_of(entry, struct dnotify_mark_entry, fsn_entry);
+ dn_mark = container_of(fsn_mark, struct dnotify_mark, fsn_mark);
mutex_lock(&dnotify_mark_mutex);
- spin_lock(&entry->lock);
- prev = &dnentry->dn;
+ spin_lock(&fsn_mark->lock);
+ prev = &dn_mark->dn;
while ((dn = *prev) != NULL) {
if ((dn->dn_owner == id) && (dn->dn_filp == filp)) {
*prev = dn->dn_next;
kmem_cache_free(dnotify_struct_cache, dn);
- dnotify_recalc_inode_mask(entry);
+ dnotify_recalc_inode_mask(fsn_mark);
break;
}
prev = &dn->dn_next;
}
- spin_unlock(&entry->lock);
+ spin_unlock(&fsn_mark->lock);
/* nothing else could have found us thanks to the dnotify_mark_mutex */
- if (dnentry->dn == NULL)
- fsnotify_destroy_mark_by_entry(entry);
-
- fsnotify_recalc_group_mask(dnotify_group);
+ if (dn_mark->dn == NULL)
+ fsnotify_destroy_mark(fsn_mark);
mutex_unlock(&dnotify_mark_mutex);
- fsnotify_put_mark(entry);
+ fsnotify_put_mark(fsn_mark);
}
/* this conversion is done only at watch creation */
@@ -259,16 +233,16 @@ static __u32 convert_arg(unsigned long arg)
/*
* If multiple processes watch the same inode with dnotify there is only one
- * dnotify mark in inode->i_fsnotify_mark_entries but we chain a dnotify_struct
+ * dnotify mark in inode->i_fsnotify_marks but we chain a dnotify_struct
* onto that mark. This function either attaches the new dnotify_struct onto
* that list, or it |= the mask onto an existing dnofiy_struct.
*/
-static int attach_dn(struct dnotify_struct *dn, struct dnotify_mark_entry *dnentry,
+static int attach_dn(struct dnotify_struct *dn, struct dnotify_mark *dn_mark,
fl_owner_t id, int fd, struct file *filp, __u32 mask)
{
struct dnotify_struct *odn;
- odn = dnentry->dn;
+ odn = dn_mark->dn;
while (odn != NULL) {
/* adding more events to existing dnofiy_struct? */
if ((odn->dn_owner == id) && (odn->dn_filp == filp)) {
@@ -283,8 +257,8 @@ static int attach_dn(struct dnotify_struct *dn, struct dnotify_mark_entry *dnent
dn->dn_fd = fd;
dn->dn_filp = filp;
dn->dn_owner = id;
- dn->dn_next = dnentry->dn;
- dnentry->dn = dn;
+ dn->dn_next = dn_mark->dn;
+ dn_mark->dn = dn;
return 0;
}
@@ -296,8 +270,8 @@ static int attach_dn(struct dnotify_struct *dn, struct dnotify_mark_entry *dnent
*/
int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
{
- struct dnotify_mark_entry *new_dnentry, *dnentry;
- struct fsnotify_mark_entry *new_entry, *entry;
+ struct dnotify_mark *new_dn_mark, *dn_mark;
+ struct fsnotify_mark *new_fsn_mark, *fsn_mark;
struct dnotify_struct *dn;
struct inode *inode;
fl_owner_t id = current->files;
@@ -306,7 +280,7 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
__u32 mask;
/* we use these to tell if we need to kfree */
- new_entry = NULL;
+ new_fsn_mark = NULL;
dn = NULL;
if (!dir_notify_enable) {
@@ -336,8 +310,8 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
}
/* new fsnotify mark, we expect most fcntl calls to add a new mark */
- new_dnentry = kmem_cache_alloc(dnotify_mark_entry_cache, GFP_KERNEL);
- if (!new_dnentry) {
+ new_dn_mark = kmem_cache_alloc(dnotify_mark_cache, GFP_KERNEL);
+ if (!new_dn_mark) {
error = -ENOMEM;
goto out_err;
}
@@ -345,29 +319,27 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
/* convert the userspace DN_* "arg" to the internal FS_* defines in fsnotify */
mask = convert_arg(arg);
- /* set up the new_entry and new_dnentry */
- new_entry = &new_dnentry->fsn_entry;
- fsnotify_init_mark(new_entry, dnotify_free_mark);
- new_entry->mask = mask;
- new_dnentry->dn = NULL;
+ /* set up the new_fsn_mark and new_dn_mark */
+ new_fsn_mark = &new_dn_mark->fsn_mark;
+ fsnotify_init_mark(new_fsn_mark, dnotify_free_mark);
+ new_fsn_mark->mask = mask;
+ new_dn_mark->dn = NULL;
/* this is needed to prevent the fcntl/close race described below */
mutex_lock(&dnotify_mark_mutex);
- /* add the new_entry or find an old one. */
- spin_lock(&inode->i_lock);
- entry = fsnotify_find_mark_entry(dnotify_group, inode);
- spin_unlock(&inode->i_lock);
- if (entry) {
- dnentry = container_of(entry, struct dnotify_mark_entry, fsn_entry);
- spin_lock(&entry->lock);
+ /* add the new_fsn_mark or find an old one. */
+ fsn_mark = fsnotify_find_inode_mark(dnotify_group, inode);
+ if (fsn_mark) {
+ dn_mark = container_of(fsn_mark, struct dnotify_mark, fsn_mark);
+ spin_lock(&fsn_mark->lock);
} else {
- fsnotify_add_mark(new_entry, dnotify_group, inode);
- spin_lock(&new_entry->lock);
- entry = new_entry;
- dnentry = new_dnentry;
- /* we used new_entry, so don't free it */
- new_entry = NULL;
+ fsnotify_add_mark(new_fsn_mark, dnotify_group, inode, NULL, 0);
+ spin_lock(&new_fsn_mark->lock);
+ fsn_mark = new_fsn_mark;
+ dn_mark = new_dn_mark;
+ /* we used new_fsn_mark, so don't free it */
+ new_fsn_mark = NULL;
}
rcu_read_lock();
@@ -376,17 +348,17 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
/* if (f != filp) means that we lost a race and another task/thread
* actually closed the fd we are still playing with before we grabbed
- * the dnotify_mark_mutex and entry->lock. Since closing the fd is the
- * only time we clean up the mark entries we need to get our mark off
+ * the dnotify_mark_mutex and fsn_mark->lock. Since closing the fd is the
+ * only time we clean up the marks we need to get our mark off
* the list. */
if (f != filp) {
/* if we added ourselves, shoot ourselves, it's possible that
- * the flush actually did shoot this entry. That's fine too
+ * the flush actually did shoot this fsn_mark. That's fine too
* since multiple calls to destroy_mark is perfectly safe, if
- * we found a dnentry already attached to the inode, just sod
+ * we found a dn_mark already attached to the inode, just sod
* off silently as the flush at close time dealt with it.
*/
- if (dnentry == new_dnentry)
+ if (dn_mark == new_dn_mark)
destroy = 1;
goto out;
}
@@ -394,13 +366,13 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
error = __f_setown(filp, task_pid(current), PIDTYPE_PID, 0);
if (error) {
/* if we added, we must shoot */
- if (dnentry == new_dnentry)
+ if (dn_mark == new_dn_mark)
destroy = 1;
goto out;
}
- error = attach_dn(dn, dnentry, id, fd, filp, mask);
- /* !error means that we attached the dn to the dnentry, so don't free it */
+ error = attach_dn(dn, dn_mark, id, fd, filp, mask);
+ /* !error means that we attached the dn to the dn_mark, so don't free it */
if (!error)
dn = NULL;
/* -EEXIST means that we didn't add this new dn and used an old one.
@@ -408,20 +380,18 @@ int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
else if (error == -EEXIST)
error = 0;
- dnotify_recalc_inode_mask(entry);
+ dnotify_recalc_inode_mask(fsn_mark);
out:
- spin_unlock(&entry->lock);
+ spin_unlock(&fsn_mark->lock);
if (destroy)
- fsnotify_destroy_mark_by_entry(entry);
-
- fsnotify_recalc_group_mask(dnotify_group);
+ fsnotify_destroy_mark(fsn_mark);
mutex_unlock(&dnotify_mark_mutex);
- fsnotify_put_mark(entry);
+ fsnotify_put_mark(fsn_mark);
out_err:
- if (new_entry)
- fsnotify_put_mark(new_entry);
+ if (new_fsn_mark)
+ fsnotify_put_mark(new_fsn_mark);
if (dn)
kmem_cache_free(dnotify_struct_cache, dn);
return error;
@@ -430,10 +400,9 @@ out_err:
static int __init dnotify_init(void)
{
dnotify_struct_cache = KMEM_CACHE(dnotify_struct, SLAB_PANIC);
- dnotify_mark_entry_cache = KMEM_CACHE(dnotify_mark_entry, SLAB_PANIC);
+ dnotify_mark_cache = KMEM_CACHE(dnotify_mark, SLAB_PANIC);
- dnotify_group = fsnotify_obtain_group(DNOTIFY_GROUP_NUM,
- 0, &dnotify_fsnotify_ops);
+ dnotify_group = fsnotify_alloc_group(&dnotify_fsnotify_ops);
if (IS_ERR(dnotify_group))
panic("unable to allocate fsnotify group for dnotify\n");
return 0;
diff --git a/fs/notify/fanotify/Kconfig b/fs/notify/fanotify/Kconfig
new file mode 100644
index 000000000000..3ac36b7bf6b9
--- /dev/null
+++ b/fs/notify/fanotify/Kconfig
@@ -0,0 +1,26 @@
+config FANOTIFY
+ bool "Filesystem wide access notification"
+ select FSNOTIFY
+ select ANON_INODES
+ default n
+ ---help---
+ Say Y here to enable fanotify suport. fanotify is a file access
+ notification system which differs from inotify in that it sends
+ and open file descriptor to the userspace listener along with
+ the event.
+
+ If unsure, say Y.
+
+config FANOTIFY_ACCESS_PERMISSIONS
+ bool "fanotify permissions checking"
+ depends on FANOTIFY
+ depends on SECURITY
+ default n
+ ---help---
+ Say Y here is you want fanotify listeners to be able to make permissions
+ decisions concerning filesystem events. This is used by some fanotify
+ listeners which need to scan files before allowing the system access to
+ use those files. This is used by some anti-malware vendors and by some
+ hierarchical storage managent systems.
+
+ If unsure, say N.
diff --git a/fs/notify/fanotify/Makefile b/fs/notify/fanotify/Makefile
new file mode 100644
index 000000000000..0999213e7e6e
--- /dev/null
+++ b/fs/notify/fanotify/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_FANOTIFY) += fanotify.o fanotify_user.o
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
new file mode 100644
index 000000000000..eb8f73c9c131
--- /dev/null
+++ b/fs/notify/fanotify/fanotify.c
@@ -0,0 +1,212 @@
+#include <linux/fanotify.h>
+#include <linux/fdtable.h>
+#include <linux/fsnotify_backend.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h> /* UINT_MAX */
+#include <linux/mount.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+
+static bool should_merge(struct fsnotify_event *old, struct fsnotify_event *new)
+{
+ pr_debug("%s: old=%p new=%p\n", __func__, old, new);
+
+ if (old->to_tell == new->to_tell &&
+ old->data_type == new->data_type &&
+ old->tgid == new->tgid) {
+ switch (old->data_type) {
+ case (FSNOTIFY_EVENT_FILE):
+ if ((old->file->f_path.mnt == new->file->f_path.mnt) &&
+ (old->file->f_path.dentry == new->file->f_path.dentry))
+ return true;
+ case (FSNOTIFY_EVENT_NONE):
+ return true;
+ default:
+ BUG();
+ };
+ }
+ return false;
+}
+
+/* and the list better be locked by something too! */
+static struct fsnotify_event *fanotify_merge(struct list_head *list,
+ struct fsnotify_event *event)
+{
+ struct fsnotify_event_holder *test_holder;
+ struct fsnotify_event *test_event = NULL;
+ struct fsnotify_event *new_event;
+
+ pr_debug("%s: list=%p event=%p\n", __func__, list, event);
+
+
+ list_for_each_entry_reverse(test_holder, list, event_list) {
+ if (should_merge(test_holder->event, event)) {
+ test_event = test_holder->event;
+ break;
+ }
+ }
+
+ if (!test_event)
+ return NULL;
+
+ fsnotify_get_event(test_event);
+
+ /* if they are exactly the same we are done */
+ if (test_event->mask == event->mask)
+ return test_event;
+
+ /*
+ * if the refcnt == 2 this is the only queue
+ * for this event and so we can update the mask
+ * in place.
+ */
+ if (atomic_read(&test_event->refcnt) == 2) {
+ test_event->mask |= event->mask;
+ return test_event;
+ }
+
+ new_event = fsnotify_clone_event(test_event);
+
+ /* done with test_event */
+ fsnotify_put_event(test_event);
+
+ /* couldn't allocate memory, merge was not possible */
+ if (unlikely(!new_event))
+ return ERR_PTR(-ENOMEM);
+
+ /* build new event and replace it on the list */
+ new_event->mask = (test_event->mask | event->mask);
+ fsnotify_replace_event(test_holder, new_event);
+
+ /* we hold a reference on new_event from clone_event */
+ return new_event;
+}
+
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+static int fanotify_get_response_from_access(struct fsnotify_group *group,
+ struct fsnotify_event *event)
+{
+ int ret;
+
+ pr_debug("%s: group=%p event=%p\n", __func__, group, event);
+
+ wait_event(group->fanotify_data.access_waitq, event->response);
+
+ /* userspace responded, convert to something usable */
+ spin_lock(&event->lock);
+ switch (event->response) {
+ case FAN_ALLOW:
+ ret = 0;
+ break;
+ case FAN_DENY:
+ default:
+ ret = -EPERM;
+ }
+ event->response = 0;
+ spin_unlock(&event->lock);
+
+ pr_debug("%s: group=%p event=%p about to return ret=%d\n", __func__,
+ group, event, ret);
+
+ return ret;
+}
+#endif
+
+static int fanotify_handle_event(struct fsnotify_group *group,
+ struct fsnotify_mark *inode_mark,
+ struct fsnotify_mark *fanotify_mark,
+ struct fsnotify_event *event)
+{
+ int ret = 0;
+ struct fsnotify_event *notify_event = NULL;
+
+ BUILD_BUG_ON(FAN_ACCESS != FS_ACCESS);
+ BUILD_BUG_ON(FAN_MODIFY != FS_MODIFY);
+ BUILD_BUG_ON(FAN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE);
+ BUILD_BUG_ON(FAN_CLOSE_WRITE != FS_CLOSE_WRITE);
+ BUILD_BUG_ON(FAN_OPEN != FS_OPEN);
+ BUILD_BUG_ON(FAN_EVENT_ON_CHILD != FS_EVENT_ON_CHILD);
+ BUILD_BUG_ON(FAN_Q_OVERFLOW != FS_Q_OVERFLOW);
+ BUILD_BUG_ON(FAN_OPEN_PERM != FS_OPEN_PERM);
+ BUILD_BUG_ON(FAN_ACCESS_PERM != FS_ACCESS_PERM);
+
+ pr_debug("%s: group=%p event=%p\n", __func__, group, event);
+
+ notify_event = fsnotify_add_notify_event(group, event, NULL, fanotify_merge);
+ if (IS_ERR(notify_event))
+ return PTR_ERR(notify_event);
+
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+ if (event->mask & FAN_ALL_PERM_EVENTS) {
+ /* if we merged we need to wait on the new event */
+ if (notify_event)
+ event = notify_event;
+ ret = fanotify_get_response_from_access(group, event);
+ }
+#endif
+
+ if (notify_event)
+ fsnotify_put_event(notify_event);
+
+ return ret;
+}
+
+static bool fanotify_should_send_event(struct fsnotify_group *group,
+ struct inode *to_tell,
+ struct fsnotify_mark *inode_mark,
+ struct fsnotify_mark *vfsmnt_mark,
+ __u32 event_mask, void *data, int data_type)
+{
+ __u32 marks_mask, marks_ignored_mask;
+
+ pr_debug("%s: group=%p to_tell=%p inode_mark=%p vfsmnt_mark=%p "
+ "mask=%x data=%p data_type=%d\n", __func__, group, to_tell,
+ inode_mark, vfsmnt_mark, event_mask, data, data_type);
+
+ pr_debug("%s: group=%p vfsmount_mark=%p inode_mark=%p mask=%x\n",
+ __func__, group, vfsmnt_mark, inode_mark, event_mask);
+
+ /* sorry, fanotify only gives a damn about files and dirs */
+ if (!S_ISREG(to_tell->i_mode) &&
+ !S_ISDIR(to_tell->i_mode))
+ return false;
+
+ /* if we don't have enough info to send an event to userspace say no */
+ if (data_type != FSNOTIFY_EVENT_FILE)
+ return false;
+
+ if (inode_mark && vfsmnt_mark) {
+ marks_mask = (vfsmnt_mark->mask | inode_mark->mask);
+ marks_ignored_mask = (vfsmnt_mark->ignored_mask | inode_mark->ignored_mask);
+ } else if (inode_mark) {
+ /*
+ * if the event is for a child and this inode doesn't care about
+ * events on the child, don't send it!
+ */
+ if ((event_mask & FS_EVENT_ON_CHILD) &&
+ !(inode_mark->mask & FS_EVENT_ON_CHILD))
+ return false;
+ marks_mask = inode_mark->mask;
+ marks_ignored_mask = inode_mark->ignored_mask;
+ } else if (vfsmnt_mark) {
+ marks_mask = vfsmnt_mark->mask;
+ marks_ignored_mask = vfsmnt_mark->ignored_mask;
+ } else {
+ BUG();
+ }
+
+ if (event_mask & marks_mask & ~marks_ignored_mask)
+ return true;
+
+ return false;
+}
+
+const struct fsnotify_ops fanotify_fsnotify_ops = {
+ .handle_event = fanotify_handle_event,
+ .should_send_event = fanotify_should_send_event,
+ .free_group_priv = NULL,
+ .free_event_priv = NULL,
+ .freeing_mark = NULL,
+};
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
new file mode 100644
index 000000000000..25a3b4dfcf61
--- /dev/null
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -0,0 +1,760 @@
+#include <linux/fanotify.h>
+#include <linux/fcntl.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/anon_inodes.h>
+#include <linux/fsnotify_backend.h>
+#include <linux/init.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/poll.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+#include <asm/ioctls.h>
+
+extern const struct fsnotify_ops fanotify_fsnotify_ops;
+
+static struct kmem_cache *fanotify_mark_cache __read_mostly;
+static struct kmem_cache *fanotify_response_event_cache __read_mostly;
+
+struct fanotify_response_event {
+ struct list_head list;
+ __s32 fd;
+ struct fsnotify_event *event;
+};
+
+/*
+ * Get an fsnotify notification event if one exists and is small
+ * enough to fit in "count". Return an error pointer if the count
+ * is not large enough.
+ *
+ * Called with the group->notification_mutex held.
+ */
+static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
+ size_t count)
+{
+ BUG_ON(!mutex_is_locked(&group->notification_mutex));
+
+ pr_debug("%s: group=%p count=%zd\n", __func__, group, count);
+
+ if (fsnotify_notify_queue_is_empty(group))
+ return NULL;
+
+ if (FAN_EVENT_METADATA_LEN > count)
+ return ERR_PTR(-EINVAL);
+
+ /* held the notification_mutex the whole time, so this is the
+ * same event we peeked above */
+ return fsnotify_remove_notify_event(group);
+}
+
+static int create_fd(struct fsnotify_group *group, struct fsnotify_event *event)
+{
+ int client_fd;
+ struct dentry *dentry;
+ struct vfsmount *mnt;
+ struct file *new_file;
+
+ pr_debug("%s: group=%p event=%p\n", __func__, group, event);
+
+ client_fd = get_unused_fd();
+ if (client_fd < 0)
+ return client_fd;
+
+ if (event->data_type != FSNOTIFY_EVENT_FILE) {
+ WARN_ON(1);
+ put_unused_fd(client_fd);
+ return -EINVAL;
+ }
+
+ /*
+ * we need a new file handle for the userspace program so it can read even if it was
+ * originally opened O_WRONLY.
+ */
+ dentry = dget(event->file->f_path.dentry);
+ mnt = mntget(event->file->f_path.mnt);
+ /* it's possible this event was an overflow event. in that case dentry and mnt
+ * are NULL; That's fine, just don't call dentry open */
+ if (dentry && mnt)
+ new_file = dentry_open(dentry, mnt,
+ group->fanotify_data.f_flags | FMODE_NONOTIFY,
+ current_cred());
+ else
+ new_file = ERR_PTR(-EOVERFLOW);
+ if (IS_ERR(new_file)) {
+ /*
+ * we still send an event even if we can't open the file. this
+ * can happen when say tasks are gone and we try to open their
+ * /proc files or we try to open a WRONLY file like in sysfs
+ * we just send the errno to userspace since there isn't much
+ * else we can do.
+ */
+ put_unused_fd(client_fd);
+ client_fd = PTR_ERR(new_file);
+ } else {
+ fd_install(client_fd, new_file);
+ }
+
+ return client_fd;
+}
+
+static ssize_t fill_event_metadata(struct fsnotify_group *group,
+ struct fanotify_event_metadata *metadata,
+ struct fsnotify_event *event)
+{
+ pr_debug("%s: group=%p metadata=%p event=%p\n", __func__,
+ group, metadata, event);
+
+ metadata->event_len = FAN_EVENT_METADATA_LEN;
+ metadata->vers = FANOTIFY_METADATA_VERSION;
+ metadata->mask = event->mask & FAN_ALL_OUTGOING_EVENTS;
+ metadata->pid = pid_vnr(event->tgid);
+ metadata->fd = create_fd(group, event);
+
+ return metadata->fd;
+}
+
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+static struct fanotify_response_event *dequeue_re(struct fsnotify_group *group,
+ __s32 fd)
+{
+ struct fanotify_response_event *re, *return_re = NULL;
+
+ mutex_lock(&group->fanotify_data.access_mutex);
+ list_for_each_entry(re, &group->fanotify_data.access_list, list) {
+ if (re->fd != fd)
+ continue;
+
+ list_del_init(&re->list);
+ return_re = re;
+ break;
+ }
+ mutex_unlock(&group->fanotify_data.access_mutex);
+
+ pr_debug("%s: found return_re=%p\n", __func__, return_re);
+
+ return return_re;
+}
+
+static int process_access_response(struct fsnotify_group *group,
+ struct fanotify_response *response_struct)
+{
+ struct fanotify_response_event *re;
+ __s32 fd = response_struct->fd;
+ __u32 response = response_struct->response;
+
+ pr_debug("%s: group=%p fd=%d response=%d\n", __func__, group,
+ fd, response);
+ /*
+ * make sure the response is valid, if invalid we do nothing and either
+ * userspace can send a valid responce or we will clean it up after the
+ * timeout
+ */
+ switch (response) {
+ case FAN_ALLOW:
+ case FAN_DENY:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (fd < 0)
+ return -EINVAL;
+
+ re = dequeue_re(group, fd);
+ if (!re)
+ return -ENOENT;
+
+ re->event->response = response;
+
+ wake_up(&group->fanotify_data.access_waitq);
+
+ kmem_cache_free(fanotify_response_event_cache, re);
+
+ return 0;
+}
+
+static int prepare_for_access_response(struct fsnotify_group *group,
+ struct fsnotify_event *event,
+ __s32 fd)
+{
+ struct fanotify_response_event *re;
+
+ if (!(event->mask & FAN_ALL_PERM_EVENTS))
+ return 0;
+
+ re = kmem_cache_alloc(fanotify_response_event_cache, GFP_KERNEL);
+ if (!re)
+ return -ENOMEM;
+
+ re->event = event;
+ re->fd = fd;
+
+ mutex_lock(&group->fanotify_data.access_mutex);
+ list_add_tail(&re->list, &group->fanotify_data.access_list);
+ mutex_unlock(&group->fanotify_data.access_mutex);
+
+ return 0;
+}
+
+static void remove_access_response(struct fsnotify_group *group,
+ struct fsnotify_event *event,
+ __s32 fd)
+{
+ struct fanotify_response_event *re;
+
+ if (!(event->mask & FAN_ALL_PERM_EVENTS))
+ return;
+
+ re = dequeue_re(group, fd);
+ if (!re)
+ return;
+
+ BUG_ON(re->event != event);
+
+ kmem_cache_free(fanotify_response_event_cache, re);
+
+ return;
+}
+#else
+static int prepare_for_access_response(struct fsnotify_group *group,
+ struct fsnotify_event *event,
+ __s32 fd)
+{
+ return 0;
+}
+
+static void remove_access_response(struct fsnotify_group *group,
+ struct fsnotify_event *event,
+ __s32 fd)
+{
+ return;
+}
+#endif
+
+static ssize_t copy_event_to_user(struct fsnotify_group *group,
+ struct fsnotify_event *event,
+ char __user *buf)
+{
+ struct fanotify_event_metadata fanotify_event_metadata;
+ int fd, ret;
+
+ pr_debug("%s: group=%p event=%p\n", __func__, group, event);
+
+ fd = fill_event_metadata(group, &fanotify_event_metadata, event);
+ if (fd < 0)
+ return fd;
+
+ ret = prepare_for_access_response(group, event, fd);
+ if (ret)
+ goto out_close_fd;
+
+ ret = -EFAULT;
+ if (copy_to_user(buf, &fanotify_event_metadata, FAN_EVENT_METADATA_LEN))
+ goto out_kill_access_response;
+
+ return FAN_EVENT_METADATA_LEN;
+
+out_kill_access_response:
+ remove_access_response(group, event, fd);
+out_close_fd:
+ sys_close(fd);
+ return ret;
+}
+
+/* intofiy userspace file descriptor functions */
+static unsigned int fanotify_poll(struct file *file, poll_table *wait)
+{
+ struct fsnotify_group *group = file->private_data;
+ int ret = 0;
+
+ poll_wait(file, &group->notification_waitq, wait);
+ mutex_lock(&group->notification_mutex);
+ if (!fsnotify_notify_queue_is_empty(group))
+ ret = POLLIN | POLLRDNORM;
+ mutex_unlock(&group->notification_mutex);
+
+ return ret;
+}
+
+static ssize_t fanotify_read(struct file *file, char __user *buf,
+ size_t count, loff_t *pos)
+{
+ struct fsnotify_group *group;
+ struct fsnotify_event *kevent;
+ char __user *start;
+ int ret;
+ DEFINE_WAIT(wait);
+
+ start = buf;
+ group = file->private_data;
+
+ pr_debug("%s: group=%p\n", __func__, group);
+
+ while (1) {
+ prepare_to_wait(&group->notification_waitq, &wait, TASK_INTERRUPTIBLE);
+
+ mutex_lock(&group->notification_mutex);
+ kevent = get_one_event(group, count);
+ mutex_unlock(&group->notification_mutex);
+
+ if (kevent) {
+ ret = PTR_ERR(kevent);
+ if (IS_ERR(kevent))
+ break;
+ ret = copy_event_to_user(group, kevent, buf);
+ fsnotify_put_event(kevent);
+ if (ret < 0)
+ break;
+ buf += ret;
+ count -= ret;
+ continue;
+ }
+
+ ret = -EAGAIN;
+ if (file->f_flags & O_NONBLOCK)
+ break;
+ ret = -EINTR;
+ if (signal_pending(current))
+ break;
+
+ if (start != buf)
+ break;
+
+ schedule();
+ }
+
+ finish_wait(&group->notification_waitq, &wait);
+ if (start != buf && ret != -EFAULT)
+ ret = buf - start;
+ return ret;
+}
+
+static ssize_t fanotify_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
+{
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+ struct fanotify_response response = { .fd = -1, .response = -1 };
+ struct fsnotify_group *group;
+ int ret;
+
+ group = file->private_data;
+
+ if (count > sizeof(response))
+ count = sizeof(response);
+
+ pr_debug("%s: group=%p count=%zu\n", __func__, group, count);
+
+ if (copy_from_user(&response, buf, count))
+ return -EFAULT;
+
+ ret = process_access_response(group, &response);
+ if (ret < 0)
+ count = ret;
+
+ return count;
+#else
+ return -EINVAL;
+#endif
+}
+
+static int fanotify_release(struct inode *ignored, struct file *file)
+{
+ struct fsnotify_group *group = file->private_data;
+
+ pr_debug("%s: file=%p group=%p\n", __func__, file, group);
+
+ /* matches the fanotify_init->fsnotify_alloc_group */
+ fsnotify_put_group(group);
+
+ return 0;
+}
+
+static long fanotify_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct fsnotify_group *group;
+ struct fsnotify_event_holder *holder;
+ void __user *p;
+ int ret = -ENOTTY;
+ size_t send_len = 0;
+
+ group = file->private_data;
+
+ p = (void __user *) arg;
+
+ switch (cmd) {
+ case FIONREAD:
+ mutex_lock(&group->notification_mutex);
+ list_for_each_entry(holder, &group->notification_list, event_list)
+ send_len += FAN_EVENT_METADATA_LEN;
+ mutex_unlock(&group->notification_mutex);
+ ret = put_user(send_len, (int __user *) p);
+ break;
+ }
+
+ return ret;
+}
+
+static const struct file_operations fanotify_fops = {
+ .poll = fanotify_poll,
+ .read = fanotify_read,
+ .write = fanotify_write,
+ .fasync = NULL,
+ .release = fanotify_release,
+ .unlocked_ioctl = fanotify_ioctl,
+ .compat_ioctl = fanotify_ioctl,
+};
+
+static void fanotify_free_mark(struct fsnotify_mark *fsn_mark)
+{
+ kmem_cache_free(fanotify_mark_cache, fsn_mark);
+}
+
+static int fanotify_find_path(int dfd, const char __user *filename,
+ struct path *path, unsigned int flags)
+{
+ int ret;
+
+ pr_debug("%s: dfd=%d filename=%p flags=%x\n", __func__,
+ dfd, filename, flags);
+
+ if (filename == NULL) {
+ struct file *file;
+ int fput_needed;
+
+ ret = -EBADF;
+ file = fget_light(dfd, &fput_needed);
+ if (!file)
+ goto out;
+
+ ret = -ENOTDIR;
+ if ((flags & FAN_MARK_ONLYDIR) &&
+ !(S_ISDIR(file->f_path.dentry->d_inode->i_mode))) {
+ fput_light(file, fput_needed);
+ goto out;
+ }
+
+ *path = file->f_path;
+ path_get(path);
+ fput_light(file, fput_needed);
+ } else {
+ unsigned int lookup_flags = 0;
+
+ if (!(flags & FAN_MARK_DONT_FOLLOW))
+ lookup_flags |= LOOKUP_FOLLOW;
+ if (flags & FAN_MARK_ONLYDIR)
+ lookup_flags |= LOOKUP_DIRECTORY;
+
+ ret = user_path_at(dfd, filename, lookup_flags, path);
+ if (ret)
+ goto out;
+ }
+
+ /* you can only watch an inode if you have read permissions on it */
+ ret = inode_permission(path->dentry->d_inode, MAY_READ);
+ if (ret)
+ path_put(path);
+out:
+ return ret;
+}
+
+static __u32 fanotify_mark_remove_from_mask(struct fsnotify_mark *fsn_mark,
+ __u32 mask,
+ unsigned int flags)
+{
+ __u32 oldmask;
+
+ spin_lock(&fsn_mark->lock);
+ if (!(flags & FAN_MARK_IGNORED_MASK)) {
+ oldmask = fsn_mark->mask;
+ fsnotify_set_mark_mask_locked(fsn_mark, (oldmask & ~mask));
+ } else {
+ oldmask = fsn_mark->ignored_mask;
+ fsnotify_set_mark_ignored_mask_locked(fsn_mark, (oldmask & ~mask));
+ }
+ spin_unlock(&fsn_mark->lock);
+
+ if (!(oldmask & ~mask))
+ fsnotify_destroy_mark(fsn_mark);
+
+ return mask & oldmask;
+}
+
+static int fanotify_remove_vfsmount_mark(struct fsnotify_group *group,
+ struct vfsmount *mnt, __u32 mask,
+ unsigned int flags)
+{
+ struct fsnotify_mark *fsn_mark = NULL;
+ __u32 removed;
+
+ fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);
+ if (!fsn_mark)
+ return -ENOENT;
+
+ removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags);
+ fsnotify_put_mark(fsn_mark);
+ if (removed & mnt->mnt_fsnotify_mask)
+ fsnotify_recalc_vfsmount_mask(mnt);
+
+ return 0;
+}
+
+static int fanotify_remove_inode_mark(struct fsnotify_group *group,
+ struct inode *inode, __u32 mask,
+ unsigned int flags)
+{
+ struct fsnotify_mark *fsn_mark = NULL;
+ __u32 removed;
+
+ fsn_mark = fsnotify_find_inode_mark(group, inode);
+ if (!fsn_mark)
+ return -ENOENT;
+
+ removed = fanotify_mark_remove_from_mask(fsn_mark, mask, flags);
+ /* matches the fsnotify_find_inode_mark() */
+ fsnotify_put_mark(fsn_mark);
+ if (removed & inode->i_fsnotify_mask)
+ fsnotify_recalc_inode_mask(inode);
+
+ return 0;
+}
+
+static __u32 fanotify_mark_add_to_mask(struct fsnotify_mark *fsn_mark,
+ __u32 mask,
+ unsigned int flags)
+{
+ __u32 oldmask;
+
+ spin_lock(&fsn_mark->lock);
+ if (!(flags & FAN_MARK_IGNORED_MASK)) {
+ oldmask = fsn_mark->mask;
+ fsnotify_set_mark_mask_locked(fsn_mark, (oldmask | mask));
+ } else {
+ oldmask = fsn_mark->ignored_mask;
+ fsnotify_set_mark_ignored_mask_locked(fsn_mark, (oldmask | mask));
+ if (flags & FAN_MARK_IGNORED_SURV_MODIFY)
+ fsn_mark->flags |= FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY;
+ }
+ spin_unlock(&fsn_mark->lock);
+
+ return mask & ~oldmask;
+}
+
+static int fanotify_add_vfsmount_mark(struct fsnotify_group *group,
+ struct vfsmount *mnt, __u32 mask,
+ unsigned int flags)
+{
+ struct fsnotify_mark *fsn_mark;
+ __u32 added;
+
+ fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);
+ if (!fsn_mark) {
+ int ret;
+
+ fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
+ if (!fsn_mark)
+ return -ENOMEM;
+
+ fsnotify_init_mark(fsn_mark, fanotify_free_mark);
+ ret = fsnotify_add_mark(fsn_mark, group, NULL, mnt, 0);
+ if (ret) {
+ fanotify_free_mark(fsn_mark);
+ return ret;
+ }
+ }
+ added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
+ fsnotify_put_mark(fsn_mark);
+ if (added & ~mnt->mnt_fsnotify_mask)
+ fsnotify_recalc_vfsmount_mask(mnt);
+
+ return 0;
+}
+
+static int fanotify_add_inode_mark(struct fsnotify_group *group,
+ struct inode *inode, __u32 mask,
+ unsigned int flags)
+{
+ struct fsnotify_mark *fsn_mark;
+ __u32 added;
+
+ pr_debug("%s: group=%p inode=%p\n", __func__, group, inode);
+
+ fsn_mark = fsnotify_find_inode_mark(group, inode);
+ if (!fsn_mark) {
+ int ret;
+
+ fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
+ if (!fsn_mark)
+ return -ENOMEM;
+
+ fsnotify_init_mark(fsn_mark, fanotify_free_mark);
+ ret = fsnotify_add_mark(fsn_mark, group, inode, NULL, 0);
+ if (ret) {
+ fanotify_free_mark(fsn_mark);
+ return ret;
+ }
+ }
+ added = fanotify_mark_add_to_mask(fsn_mark, mask, flags);
+ fsnotify_put_mark(fsn_mark);
+ if (added & ~inode->i_fsnotify_mask)
+ fsnotify_recalc_inode_mask(inode);
+ return 0;
+}
+
+/* fanotify syscalls */
+SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
+{
+ struct fsnotify_group *group;
+ int f_flags, fd;
+
+ pr_debug("%s: flags=%d event_f_flags=%d\n",
+ __func__, flags, event_f_flags);
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
+ if (flags & ~FAN_ALL_INIT_FLAGS)
+ return -EINVAL;
+
+ f_flags = O_RDWR | FMODE_NONOTIFY;
+ if (flags & FAN_CLOEXEC)
+ f_flags |= O_CLOEXEC;
+ if (flags & FAN_NONBLOCK)
+ f_flags |= O_NONBLOCK;
+
+ /* fsnotify_alloc_group takes a ref. Dropped in fanotify_release */
+ group = fsnotify_alloc_group(&fanotify_fsnotify_ops);
+ if (IS_ERR(group))
+ return PTR_ERR(group);
+
+ group->fanotify_data.f_flags = event_f_flags;
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+ mutex_init(&group->fanotify_data.access_mutex);
+ init_waitqueue_head(&group->fanotify_data.access_waitq);
+ INIT_LIST_HEAD(&group->fanotify_data.access_list);
+#endif
+
+ fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags);
+ if (fd < 0)
+ goto out_put_group;
+
+ return fd;
+
+out_put_group:
+ fsnotify_put_group(group);
+ return fd;
+}
+
+SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags,
+ __u64 mask, int dfd,
+ const char __user * pathname)
+{
+ struct inode *inode = NULL;
+ struct vfsmount *mnt = NULL;
+ struct fsnotify_group *group;
+ struct file *filp;
+ struct path path;
+ int ret, fput_needed;
+
+ pr_debug("%s: fanotify_fd=%d flags=%x dfd=%d pathname=%p mask=%llx\n",
+ __func__, fanotify_fd, flags, dfd, pathname, mask);
+
+ /* we only use the lower 32 bits as of right now. */
+ if (mask & ((__u64)0xffffffff << 32))
+ return -EINVAL;
+
+ if (flags & ~FAN_ALL_MARK_FLAGS)
+ return -EINVAL;
+ switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) {
+ case FAN_MARK_ADD:
+ case FAN_MARK_REMOVE:
+ case FAN_MARK_FLUSH:
+ break;
+ default:
+ return -EINVAL;
+ }
+#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS
+ if (mask & ~(FAN_ALL_EVENTS | FAN_ALL_PERM_EVENTS | FAN_EVENT_ON_CHILD))
+#else
+ if (mask & ~(FAN_ALL_EVENTS | FAN_EVENT_ON_CHILD))
+#endif
+ return -EINVAL;
+
+ filp = fget_light(fanotify_fd, &fput_needed);
+ if (unlikely(!filp))
+ return -EBADF;
+
+ /* verify that this is indeed an fanotify instance */
+ ret = -EINVAL;
+ if (unlikely(filp->f_op != &fanotify_fops))
+ goto fput_and_out;
+
+ ret = fanotify_find_path(dfd, pathname, &path, flags);
+ if (ret)
+ goto fput_and_out;
+
+ /* inode held in place by reference to path; group by fget on fd */
+ if (!(flags & FAN_MARK_MOUNT))
+ inode = path.dentry->d_inode;
+ else
+ mnt = path.mnt;
+ group = filp->private_data;
+
+ /* create/update an inode mark */
+ switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) {
+ case FAN_MARK_ADD:
+ if (flags & FAN_MARK_MOUNT)
+ ret = fanotify_add_vfsmount_mark(group, mnt, mask, flags);
+ else
+ ret = fanotify_add_inode_mark(group, inode, mask, flags);
+ break;
+ case FAN_MARK_REMOVE:
+ if (flags & FAN_MARK_MOUNT)
+ ret = fanotify_remove_vfsmount_mark(group, mnt, mask, flags);
+ else
+ ret = fanotify_remove_inode_mark(group, inode, mask, flags);
+ break;
+ case FAN_MARK_FLUSH:
+ if (flags & FAN_MARK_MOUNT)
+ fsnotify_clear_vfsmount_marks_by_group(group);
+ else
+ fsnotify_clear_inode_marks_by_group(group);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+
+ path_put(&path);
+fput_and_out:
+ fput_light(filp, fput_needed);
+ return ret;
+}
+
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+asmlinkage long SyS_fanotify_mark(long fanotify_fd, long flags, __u64 mask,
+ long dfd, long pathname)
+{
+ return SYSC_fanotify_mark((int) fanotify_fd, (unsigned int) flags,
+ mask, (int) dfd,
+ (const char __user *) pathname);
+}
+SYSCALL_ALIAS(sys_fanotify_mark, SyS_fanotify_mark);
+#endif
+
+/*
+ * fanotify_user_setup - Our initialization function. Note that we cannnot return
+ * error because we have compiled-in VFS hooks. So an (unlikely) failure here
+ * must result in panic().
+ */
+static int __init fanotify_user_setup(void)
+{
+ fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC);
+ fanotify_response_event_cache = KMEM_CACHE(fanotify_response_event,
+ SLAB_PANIC);
+
+ return 0;
+}
+device_initcall(fanotify_user_setup);
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index fcc2f064af83..4d2a82c1ceb1 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -21,6 +21,7 @@
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/module.h>
+#include <linux/mount.h>
#include <linux/srcu.h>
#include <linux/fsnotify_backend.h>
@@ -35,6 +36,11 @@ void __fsnotify_inode_delete(struct inode *inode)
}
EXPORT_SYMBOL_GPL(__fsnotify_inode_delete);
+void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
+{
+ fsnotify_clear_marks_by_mount(mnt);
+}
+
/*
* Given an inode, first check if we care what happens to our children. Inotify
* and dnotify both tell their parents about events. If we care about any event
@@ -78,13 +84,16 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode)
}
/* Notify this dentry's parent about a child's events. */
-void __fsnotify_parent(struct dentry *dentry, __u32 mask)
+void __fsnotify_parent(struct file *file, struct dentry *dentry, __u32 mask)
{
struct dentry *parent;
struct inode *p_inode;
bool send = false;
bool should_update_children = false;
+ if (!dentry)
+ dentry = file->f_path.dentry;
+
if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED))
return;
@@ -115,8 +124,12 @@ void __fsnotify_parent(struct dentry *dentry, __u32 mask)
* specifies these are events which came from a child. */
mask |= FS_EVENT_ON_CHILD;
- fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
- dentry->d_name.name, 0);
+ if (file)
+ fsnotify(p_inode, mask, file, FSNOTIFY_EVENT_FILE,
+ dentry->d_name.name, 0);
+ else
+ fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
+ dentry->d_name.name, 0);
dput(parent);
}
@@ -127,63 +140,181 @@ void __fsnotify_parent(struct dentry *dentry, __u32 mask)
}
EXPORT_SYMBOL_GPL(__fsnotify_parent);
+static int send_to_group(struct inode *to_tell, struct vfsmount *mnt,
+ struct fsnotify_mark *inode_mark,
+ struct fsnotify_mark *vfsmount_mark,
+ __u32 mask, void *data,
+ int data_is, u32 cookie,
+ const unsigned char *file_name,
+ struct fsnotify_event **event)
+{
+ struct fsnotify_group *group = inode_mark->group;
+ __u32 inode_test_mask = (mask & ~FS_EVENT_ON_CHILD);
+ __u32 vfsmount_test_mask = (mask & ~FS_EVENT_ON_CHILD);
+
+ pr_debug("%s: group=%p to_tell=%p mnt=%p mark=%p mask=%x data=%p"
+ " data_is=%d cookie=%d event=%p\n", __func__, group, to_tell,
+ mnt, inode_mark, mask, data, data_is, cookie, *event);
+
+ /* clear ignored on inode modification */
+ if (mask & FS_MODIFY) {
+ if (inode_mark &&
+ !(inode_mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
+ inode_mark->ignored_mask = 0;
+ if (vfsmount_mark &&
+ !(vfsmount_mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
+ vfsmount_mark->ignored_mask = 0;
+ }
+
+ /* does the inode mark tell us to do something? */
+ if (inode_mark) {
+ inode_test_mask &= inode_mark->mask;
+ inode_test_mask &= ~inode_mark->ignored_mask;
+ }
+
+ /* does the vfsmount_mark tell us to do something? */
+ if (vfsmount_mark) {
+ vfsmount_test_mask &= vfsmount_mark->mask;
+ vfsmount_test_mask &= ~vfsmount_mark->ignored_mask;
+ if (inode_mark)
+ vfsmount_test_mask &= ~inode_mark->ignored_mask;
+ }
+
+ if (!inode_test_mask && !vfsmount_test_mask)
+ return 0;
+
+ if (group->ops->should_send_event(group, to_tell, inode_mark,
+ vfsmount_mark, mask, data,
+ data_is) == false)
+ return 0;
+
+ if (!*event) {
+ *event = fsnotify_create_event(to_tell, mask, data,
+ data_is, file_name,
+ cookie, GFP_KERNEL);
+ if (!*event)
+ return -ENOMEM;
+ }
+ return group->ops->handle_event(group, inode_mark, vfsmount_mark, *event);
+}
+
/*
* This is the main call to fsnotify. The VFS calls into hook specific functions
* in linux/fsnotify.h. Those functions then in turn call here. Here will call
* out to all of the registered fsnotify_group. Those groups can then use the
* notification event in whatever means they feel necessary.
*/
-void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const char *file_name, u32 cookie)
+int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
+ const unsigned char *file_name, u32 cookie)
{
- struct fsnotify_group *group;
+ struct hlist_node *inode_node, *vfsmount_node;
+ struct fsnotify_mark *inode_mark = NULL, *vfsmount_mark = NULL;
+ struct fsnotify_group *inode_group, *vfsmount_group;
struct fsnotify_event *event = NULL;
- int idx;
+ struct vfsmount *mnt;
+ int idx, ret = 0;
+ bool used_inode = false, used_vfsmount = false;
/* global tests shouldn't care about events on child only the specific event */
__u32 test_mask = (mask & ~FS_EVENT_ON_CHILD);
- if (list_empty(&fsnotify_groups))
- return;
+ if (data_is == FSNOTIFY_EVENT_FILE)
+ mnt = ((struct file *)data)->f_path.mnt;
+ else
+ mnt = NULL;
- if (!(test_mask & fsnotify_mask))
- return;
-
- if (!(test_mask & to_tell->i_fsnotify_mask))
- return;
/*
- * SRCU!! the groups list is very very much read only and the path is
- * very hot. The VAST majority of events are not going to need to do
- * anything other than walk the list so it's crazy to pre-allocate.
+ * if this is a modify event we may need to clear the ignored masks
+ * otherwise return if neither the inode nor the vfsmount care about
+ * this type of event.
*/
- idx = srcu_read_lock(&fsnotify_grp_srcu);
- list_for_each_entry_rcu(group, &fsnotify_groups, group_list) {
- if (test_mask & group->mask) {
- if (!group->ops->should_send_event(group, to_tell, mask))
- continue;
- if (!event) {
- event = fsnotify_create_event(to_tell, mask, data,
- data_is, file_name, cookie,
- GFP_KERNEL);
- /* shit, we OOM'd and now we can't tell, maybe
- * someday someone else will want to do something
- * here */
- if (!event)
- break;
- }
- group->ops->handle_event(group, event);
+ if (!(mask & FS_MODIFY) &&
+ !(test_mask & to_tell->i_fsnotify_mask) &&
+ !(mnt && test_mask & mnt->mnt_fsnotify_mask))
+ return 0;
+
+ idx = srcu_read_lock(&fsnotify_mark_srcu);
+
+ if ((mask & FS_MODIFY) ||
+ (test_mask & to_tell->i_fsnotify_mask))
+ inode_node = srcu_dereference(to_tell->i_fsnotify_marks.first,
+ &fsnotify_mark_srcu);
+ else
+ inode_node = NULL;
+
+ if (mnt) {
+ if ((mask & FS_MODIFY) ||
+ (test_mask & mnt->mnt_fsnotify_mask))
+ vfsmount_node = srcu_dereference(mnt->mnt_fsnotify_marks.first,
+ &fsnotify_mark_srcu);
+ else
+ vfsmount_node = NULL;
+ } else {
+ mnt = NULL;
+ vfsmount_node = NULL;
+ }
+
+ while (inode_node || vfsmount_node) {
+ if (inode_node) {
+ inode_mark = hlist_entry(srcu_dereference(inode_node, &fsnotify_mark_srcu),
+ struct fsnotify_mark, i.i_list);
+ inode_group = inode_mark->group;
+ } else
+ inode_group = (void *)-1;
+
+ if (vfsmount_node) {
+ vfsmount_mark = hlist_entry(srcu_dereference(vfsmount_node, &fsnotify_mark_srcu),
+ struct fsnotify_mark, m.m_list);
+ vfsmount_group = vfsmount_mark->group;
+ } else
+ vfsmount_group = (void *)-1;
+
+ if (inode_group < vfsmount_group) {
+ /* handle inode */
+ send_to_group(to_tell, NULL, inode_mark, NULL, mask, data,
+ data_is, cookie, file_name, &event);
+ used_inode = true;
+ } else if (vfsmount_group < inode_group) {
+ send_to_group(to_tell, mnt, NULL, vfsmount_mark, mask, data,
+ data_is, cookie, file_name, &event);
+ used_vfsmount = true;
+ } else {
+ send_to_group(to_tell, mnt, inode_mark, vfsmount_mark,
+ mask, data, data_is, cookie, file_name,
+ &event);
+ used_vfsmount = true;
+ used_inode = true;
}
+
+ if (used_inode)
+ inode_node = srcu_dereference(inode_node->next,
+ &fsnotify_mark_srcu);
+ if (used_vfsmount)
+ vfsmount_node = srcu_dereference(vfsmount_node->next,
+ &fsnotify_mark_srcu);
}
- srcu_read_unlock(&fsnotify_grp_srcu, idx);
+
+ srcu_read_unlock(&fsnotify_mark_srcu, idx);
/*
* fsnotify_create_event() took a reference so the event can't be cleaned
* up while we are still trying to add it to lists, drop that one.
*/
if (event)
fsnotify_put_event(event);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(fsnotify);
static __init int fsnotify_init(void)
{
- return init_srcu_struct(&fsnotify_grp_srcu);
+ int ret;
+
+ BUG_ON(hweight32(ALL_FSNOTIFY_EVENTS) != 23);
+
+ ret = init_srcu_struct(&fsnotify_mark_srcu);
+ if (ret)
+ panic("initializing fsnotify_mark_srcu");
+
+ return 0;
}
-subsys_initcall(fsnotify_init);
+core_initcall(fsnotify_init);
diff --git a/fs/notify/fsnotify.h b/fs/notify/fsnotify.h
index 4dc240824b2d..85e7d2b431d9 100644
--- a/fs/notify/fsnotify.h
+++ b/fs/notify/fsnotify.h
@@ -6,21 +6,34 @@
#include <linux/srcu.h>
#include <linux/types.h>
-/* protects reads of fsnotify_groups */
-extern struct srcu_struct fsnotify_grp_srcu;
-/* all groups which receive fsnotify events */
-extern struct list_head fsnotify_groups;
-/* all bitwise OR of all event types (FS_*) for all fsnotify_groups */
-extern __u32 fsnotify_mask;
-
/* destroy all events sitting in this groups notification queue */
extern void fsnotify_flush_notify(struct fsnotify_group *group);
+/* protects reads of inode and vfsmount marks list */
+extern struct srcu_struct fsnotify_mark_srcu;
+
+extern void fsnotify_set_inode_mark_mask_locked(struct fsnotify_mark *fsn_mark,
+ __u32 mask);
+/* add a mark to an inode */
+extern int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
+ struct fsnotify_group *group, struct inode *inode,
+ int allow_dups);
+/* add a mark to a vfsmount */
+extern int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
+ struct fsnotify_group *group, struct vfsmount *mnt,
+ int allow_dups);
+
/* final kfree of a group */
extern void fsnotify_final_destroy_group(struct fsnotify_group *group);
+/* vfsmount specific destruction of a mark */
+extern void fsnotify_destroy_vfsmount_mark(struct fsnotify_mark *mark);
+/* inode specific destruction of a mark */
+extern void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark);
/* run the list of all marks associated with inode and flag them to be freed */
extern void fsnotify_clear_marks_by_inode(struct inode *inode);
+/* run the list of all marks associated with vfsmount and flag them to be freed */
+extern void fsnotify_clear_marks_by_mount(struct vfsmount *mnt);
/*
* update the dentry->d_flags of all of inode's children to indicate if inode cares
* about events that happen to its children.
diff --git a/fs/notify/group.c b/fs/notify/group.c
index 0e1677144bc5..d309f38449cb 100644
--- a/fs/notify/group.c
+++ b/fs/notify/group.c
@@ -28,64 +28,6 @@
#include <asm/atomic.h>
-/* protects writes to fsnotify_groups and fsnotify_mask */
-static DEFINE_MUTEX(fsnotify_grp_mutex);
-/* protects reads while running the fsnotify_groups list */
-struct srcu_struct fsnotify_grp_srcu;
-/* all groups registered to receive filesystem notifications */
-LIST_HEAD(fsnotify_groups);
-/* bitwise OR of all events (FS_*) interesting to some group on this system */
-__u32 fsnotify_mask;
-
-/*
- * When a new group registers or changes it's set of interesting events
- * this function updates the fsnotify_mask to contain all interesting events
- */
-void fsnotify_recalc_global_mask(void)
-{
- struct fsnotify_group *group;
- __u32 mask = 0;
- int idx;
-
- idx = srcu_read_lock(&fsnotify_grp_srcu);
- list_for_each_entry_rcu(group, &fsnotify_groups, group_list)
- mask |= group->mask;
- srcu_read_unlock(&fsnotify_grp_srcu, idx);
- fsnotify_mask = mask;
-}
-
-/*
- * Update the group->mask by running all of the marks associated with this
- * group and finding the bitwise | of all of the mark->mask. If we change
- * the group->mask we need to update the global mask of events interesting
- * to the system.
- */
-void fsnotify_recalc_group_mask(struct fsnotify_group *group)
-{
- __u32 mask = 0;
- __u32 old_mask = group->mask;
- struct fsnotify_mark_entry *entry;
-
- spin_lock(&group->mark_lock);
- list_for_each_entry(entry, &group->mark_entries, g_list)
- mask |= entry->mask;
- spin_unlock(&group->mark_lock);
-
- group->mask = mask;
-
- if (old_mask != mask)
- fsnotify_recalc_global_mask();
-}
-
-/*
- * Take a reference to a group so things found under the fsnotify_grp_mutex
- * can't get freed under us
- */
-static void fsnotify_get_group(struct fsnotify_group *group)
-{
- atomic_inc(&group->refcnt);
-}
-
/*
* Final freeing of a group
*/
@@ -110,145 +52,53 @@ void fsnotify_final_destroy_group(struct fsnotify_group *group)
*/
static void fsnotify_destroy_group(struct fsnotify_group *group)
{
- /* clear all inode mark entries for this group */
+ /* clear all inode marks for this group */
fsnotify_clear_marks_by_group(group);
+ synchronize_srcu(&fsnotify_mark_srcu);
+
/* past the point of no return, matches the initial value of 1 */
if (atomic_dec_and_test(&group->num_marks))
fsnotify_final_destroy_group(group);
}
/*
- * Remove this group from the global list of groups that will get events
- * this can be done even if there are still references and things still using
- * this group. This just stops the group from getting new events.
- */
-static void __fsnotify_evict_group(struct fsnotify_group *group)
-{
- BUG_ON(!mutex_is_locked(&fsnotify_grp_mutex));
-
- if (group->on_group_list)
- list_del_rcu(&group->group_list);
- group->on_group_list = 0;
-}
-
-/*
- * Called when a group is no longer interested in getting events. This can be
- * used if a group is misbehaving or if for some reason a group should no longer
- * get any filesystem events.
- */
-void fsnotify_evict_group(struct fsnotify_group *group)
-{
- mutex_lock(&fsnotify_grp_mutex);
- __fsnotify_evict_group(group);
- mutex_unlock(&fsnotify_grp_mutex);
-}
-
-/*
* Drop a reference to a group. Free it if it's through.
*/
void fsnotify_put_group(struct fsnotify_group *group)
{
- if (!atomic_dec_and_mutex_lock(&group->refcnt, &fsnotify_grp_mutex))
- return;
-
- /*
- * OK, now we know that there's no other users *and* we hold mutex,
- * so no new references will appear
- */
- __fsnotify_evict_group(group);
-
- /*
- * now it's off the list, so the only thing we might care about is
- * srcu access....
- */
- mutex_unlock(&fsnotify_grp_mutex);
- synchronize_srcu(&fsnotify_grp_srcu);
-
- /* and now it is really dead. _Nothing_ could be seeing it */
- fsnotify_recalc_global_mask();
- fsnotify_destroy_group(group);
-}
-
-/*
- * Simply run the fsnotify_groups list and find a group which matches
- * the given parameters. If a group is found we take a reference to that
- * group.
- */
-static struct fsnotify_group *fsnotify_find_group(unsigned int group_num, __u32 mask,
- const struct fsnotify_ops *ops)
-{
- struct fsnotify_group *group_iter;
- struct fsnotify_group *group = NULL;
-
- BUG_ON(!mutex_is_locked(&fsnotify_grp_mutex));
-
- list_for_each_entry_rcu(group_iter, &fsnotify_groups, group_list) {
- if (group_iter->group_num == group_num) {
- if ((group_iter->mask == mask) &&
- (group_iter->ops == ops)) {
- fsnotify_get_group(group_iter);
- group = group_iter;
- } else
- group = ERR_PTR(-EEXIST);
- }
- }
- return group;
+ if (atomic_dec_and_test(&group->refcnt))
+ fsnotify_destroy_group(group);
}
/*
- * Either finds an existing group which matches the group_num, mask, and ops or
- * creates a new group and adds it to the global group list. In either case we
- * take a reference for the group returned.
+ * Create a new fsnotify_group and hold a reference for the group returned.
*/
-struct fsnotify_group *fsnotify_obtain_group(unsigned int group_num, __u32 mask,
- const struct fsnotify_ops *ops)
+struct fsnotify_group *fsnotify_alloc_group(const struct fsnotify_ops *ops)
{
- struct fsnotify_group *group, *tgroup;
+ struct fsnotify_group *group;
- /* very low use, simpler locking if we just always alloc */
- group = kmalloc(sizeof(struct fsnotify_group), GFP_KERNEL);
+ group = kzalloc(sizeof(struct fsnotify_group), GFP_KERNEL);
if (!group)
return ERR_PTR(-ENOMEM);
+ /* set to 0 when there a no external references to this group */
atomic_set(&group->refcnt, 1);
-
- group->on_group_list = 0;
- group->group_num = group_num;
- group->mask = mask;
+ /*
+ * hits 0 when there are no external references AND no marks for
+ * this group
+ */
+ atomic_set(&group->num_marks, 1);
mutex_init(&group->notification_mutex);
INIT_LIST_HEAD(&group->notification_list);
init_waitqueue_head(&group->notification_waitq);
- group->q_len = 0;
group->max_events = UINT_MAX;
spin_lock_init(&group->mark_lock);
- atomic_set(&group->num_marks, 0);
- INIT_LIST_HEAD(&group->mark_entries);
+ INIT_LIST_HEAD(&group->marks_list);
group->ops = ops;
- mutex_lock(&fsnotify_grp_mutex);
- tgroup = fsnotify_find_group(group_num, mask, ops);
- if (tgroup) {
- /* group already exists */
- mutex_unlock(&fsnotify_grp_mutex);
- /* destroy the new one we made */
- fsnotify_put_group(group);
- return tgroup;
- }
-
- /* group not found, add a new one */
- list_add_rcu(&group->group_list, &fsnotify_groups);
- group->on_group_list = 1;
- /* being on the fsnotify_groups list holds one num_marks */
- atomic_inc(&group->num_marks);
-
- mutex_unlock(&fsnotify_grp_mutex);
-
- if (mask)
- fsnotify_recalc_global_mask();
-
return group;
}
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 152b83ec005d..33297c005060 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -16,72 +16,6 @@
* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
*/
-/*
- * fsnotify inode mark locking/lifetime/and refcnting
- *
- * REFCNT:
- * The mark->refcnt tells how many "things" in the kernel currently are
- * referencing this object. The object typically will live inside the kernel
- * with a refcnt of 2, one for each list it is on (i_list, g_list). Any task
- * which can find this object holding the appropriete locks, can take a reference
- * and the object itself is guarenteed to survive until the reference is dropped.
- *
- * LOCKING:
- * There are 3 spinlocks involved with fsnotify inode marks and they MUST
- * be taken in order as follows:
- *
- * entry->lock
- * group->mark_lock
- * inode->i_lock
- *
- * entry->lock protects 2 things, entry->group and entry->inode. You must hold
- * that lock to dereference either of these things (they could be NULL even with
- * the lock)
- *
- * group->mark_lock protects the mark_entries list anchored inside a given group
- * and each entry is hooked via the g_list. It also sorta protects the
- * free_g_list, which when used is anchored by a private list on the stack of the
- * task which held the group->mark_lock.
- *
- * inode->i_lock protects the i_fsnotify_mark_entries list anchored inside a
- * given inode and each entry is hooked via the i_list. (and sorta the
- * free_i_list)
- *
- *
- * LIFETIME:
- * Inode marks survive between when they are added to an inode and when their
- * refcnt==0.
- *
- * The inode mark can be cleared for a number of different reasons including:
- * - The inode is unlinked for the last time. (fsnotify_inode_remove)
- * - The inode is being evicted from cache. (fsnotify_inode_delete)
- * - The fs the inode is on is unmounted. (fsnotify_inode_delete/fsnotify_unmount_inodes)
- * - Something explicitly requests that it be removed. (fsnotify_destroy_mark_by_entry)
- * - The fsnotify_group associated with the mark is going away and all such marks
- * need to be cleaned up. (fsnotify_clear_marks_by_group)
- *
- * Worst case we are given an inode and need to clean up all the marks on that
- * inode. We take i_lock and walk the i_fsnotify_mark_entries safely. For each
- * mark on the list we take a reference (so the mark can't disappear under us).
- * We remove that mark form the inode's list of marks and we add this mark to a
- * private list anchored on the stack using i_free_list; At this point we no
- * longer fear anything finding the mark using the inode's list of marks.
- *
- * We can safely and locklessly run the private list on the stack of everything
- * we just unattached from the original inode. For each mark on the private list
- * we grab the mark-> and can thus dereference mark->group and mark->inode. If
- * we see the group and inode are not NULL we take those locks. Now holding all
- * 3 locks we can completely remove the mark from other tasks finding it in the
- * future. Remember, 10 things might already be referencing this mark, but they
- * better be holding a ref. We drop our reference we took before we unhooked it
- * from the inode. When the ref hits 0 we can free the mark.
- *
- * Very similarly for freeing by group, except we use free_g_list.
- *
- * This has the very interesting property of being able to run concurrently with
- * any (or all) other directions.
- */
-
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
@@ -95,30 +29,19 @@
#include <linux/fsnotify_backend.h>
#include "fsnotify.h"
-void fsnotify_get_mark(struct fsnotify_mark_entry *entry)
-{
- atomic_inc(&entry->refcnt);
-}
-
-void fsnotify_put_mark(struct fsnotify_mark_entry *entry)
-{
- if (atomic_dec_and_test(&entry->refcnt))
- entry->free_mark(entry);
-}
-
/*
* Recalculate the mask of events relevant to a given inode locked.
*/
static void fsnotify_recalc_inode_mask_locked(struct inode *inode)
{
- struct fsnotify_mark_entry *entry;
+ struct fsnotify_mark *mark;
struct hlist_node *pos;
__u32 new_mask = 0;
assert_spin_locked(&inode->i_lock);
- hlist_for_each_entry(entry, pos, &inode->i_fsnotify_mark_entries, i_list)
- new_mask |= entry->mask;
+ hlist_for_each_entry(mark, pos, &inode->i_fsnotify_marks, i.i_list)
+ new_mask |= mark->mask;
inode->i_fsnotify_mask = new_mask;
}
@@ -135,107 +58,26 @@ void fsnotify_recalc_inode_mask(struct inode *inode)
__fsnotify_update_child_dentry_flags(inode);
}
-/*
- * Any time a mark is getting freed we end up here.
- * The caller had better be holding a reference to this mark so we don't actually
- * do the final put under the entry->lock
- */
-void fsnotify_destroy_mark_by_entry(struct fsnotify_mark_entry *entry)
+void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark)
{
- struct fsnotify_group *group;
- struct inode *inode;
+ struct inode *inode = mark->i.inode;
- spin_lock(&entry->lock);
+ assert_spin_locked(&mark->lock);
+ assert_spin_locked(&mark->group->mark_lock);
- group = entry->group;
- inode = entry->inode;
-
- BUG_ON(group && !inode);
- BUG_ON(!group && inode);
-
- /* if !group something else already marked this to die */
- if (!group) {
- spin_unlock(&entry->lock);
- return;
- }
-
- /* 1 from caller and 1 for being on i_list/g_list */
- BUG_ON(atomic_read(&entry->refcnt) < 2);
-
- spin_lock(&group->mark_lock);
spin_lock(&inode->i_lock);
- hlist_del_init(&entry->i_list);
- entry->inode = NULL;
-
- list_del_init(&entry->g_list);
- entry->group = NULL;
-
- fsnotify_put_mark(entry); /* for i_list and g_list */
+ hlist_del_init_rcu(&mark->i.i_list);
+ mark->i.inode = NULL;
/*
- * this mark is now off the inode->i_fsnotify_mark_entries list and we
+ * this mark is now off the inode->i_fsnotify_marks list and we
* hold the inode->i_lock, so this is the perfect time to update the
* inode->i_fsnotify_mask
*/
fsnotify_recalc_inode_mask_locked(inode);
spin_unlock(&inode->i_lock);
- spin_unlock(&group->mark_lock);
- spin_unlock(&entry->lock);
-
- /*
- * Some groups like to know that marks are being freed. This is a
- * callback to the group function to let it know that this entry
- * is being freed.
- */
- if (group->ops->freeing_mark)
- group->ops->freeing_mark(entry, group);
-
- /*
- * __fsnotify_update_child_dentry_flags(inode);
- *
- * I really want to call that, but we can't, we have no idea if the inode
- * still exists the second we drop the entry->lock.
- *
- * The next time an event arrive to this inode from one of it's children
- * __fsnotify_parent will see that the inode doesn't care about it's
- * children and will update all of these flags then. So really this
- * is just a lazy update (and could be a perf win...)
- */
-
-
- iput(inode);
-
- /*
- * it's possible that this group tried to destroy itself, but this
- * this mark was simultaneously being freed by inode. If that's the
- * case, we finish freeing the group here.
- */
- if (unlikely(atomic_dec_and_test(&group->num_marks)))
- fsnotify_final_destroy_group(group);
-}
-
-/*
- * Given a group, destroy all of the marks associated with that group.
- */
-void fsnotify_clear_marks_by_group(struct fsnotify_group *group)
-{
- struct fsnotify_mark_entry *lentry, *entry;
- LIST_HEAD(free_list);
-
- spin_lock(&group->mark_lock);
- list_for_each_entry_safe(entry, lentry, &group->mark_entries, g_list) {
- list_add(&entry->free_g_list, &free_list);
- list_del_init(&entry->g_list);
- fsnotify_get_mark(entry);
- }
- spin_unlock(&group->mark_lock);
-
- list_for_each_entry_safe(entry, lentry, &free_list, free_g_list) {
- fsnotify_destroy_mark_by_entry(entry);
- fsnotify_put_mark(entry);
- }
}
/*
@@ -243,112 +85,145 @@ void fsnotify_clear_marks_by_group(struct fsnotify_group *group)
*/
void fsnotify_clear_marks_by_inode(struct inode *inode)
{
- struct fsnotify_mark_entry *entry, *lentry;
+ struct fsnotify_mark *mark, *lmark;
struct hlist_node *pos, *n;
LIST_HEAD(free_list);
spin_lock(&inode->i_lock);
- hlist_for_each_entry_safe(entry, pos, n, &inode->i_fsnotify_mark_entries, i_list) {
- list_add(&entry->free_i_list, &free_list);
- hlist_del_init(&entry->i_list);
- fsnotify_get_mark(entry);
+ hlist_for_each_entry_safe(mark, pos, n, &inode->i_fsnotify_marks, i.i_list) {
+ list_add(&mark->i.free_i_list, &free_list);
+ hlist_del_init_rcu(&mark->i.i_list);
+ fsnotify_get_mark(mark);
}
spin_unlock(&inode->i_lock);
- list_for_each_entry_safe(entry, lentry, &free_list, free_i_list) {
- fsnotify_destroy_mark_by_entry(entry);
- fsnotify_put_mark(entry);
+ list_for_each_entry_safe(mark, lmark, &free_list, i.free_i_list) {
+ fsnotify_destroy_mark(mark);
+ fsnotify_put_mark(mark);
}
}
/*
+ * Given a group clear all of the inode marks associated with that group.
+ */
+void fsnotify_clear_inode_marks_by_group(struct fsnotify_group *group)
+{
+ fsnotify_clear_marks_by_group_flags(group, FSNOTIFY_MARK_FLAG_INODE);
+}
+
+/*
* given a group and inode, find the mark associated with that combination.
* if found take a reference to that mark and return it, else return NULL
*/
-struct fsnotify_mark_entry *fsnotify_find_mark_entry(struct fsnotify_group *group,
- struct inode *inode)
+struct fsnotify_mark *fsnotify_find_inode_mark_locked(struct fsnotify_group *group,
+ struct inode *inode)
{
- struct fsnotify_mark_entry *entry;
+ struct fsnotify_mark *mark;
struct hlist_node *pos;
assert_spin_locked(&inode->i_lock);
- hlist_for_each_entry(entry, pos, &inode->i_fsnotify_mark_entries, i_list) {
- if (entry->group == group) {
- fsnotify_get_mark(entry);
- return entry;
+ hlist_for_each_entry(mark, pos, &inode->i_fsnotify_marks, i.i_list) {
+ if (mark->group == group) {
+ fsnotify_get_mark(mark);
+ return mark;
}
}
return NULL;
}
/*
- * Nothing fancy, just initialize lists and locks and counters.
+ * given a group and inode, find the mark associated with that combination.
+ * if found take a reference to that mark and return it, else return NULL
*/
-void fsnotify_init_mark(struct fsnotify_mark_entry *entry,
- void (*free_mark)(struct fsnotify_mark_entry *entry))
+struct fsnotify_mark *fsnotify_find_inode_mark(struct fsnotify_group *group,
+ struct inode *inode)
+{
+ struct fsnotify_mark *mark;
+
+ spin_lock(&inode->i_lock);
+ mark = fsnotify_find_inode_mark_locked(group, inode);
+ spin_unlock(&inode->i_lock);
+ return mark;
+}
+
+/*
+ * If we are setting a mark mask on an inode mark we should pin the inode
+ * in memory.
+ */
+void fsnotify_set_inode_mark_mask_locked(struct fsnotify_mark *mark,
+ __u32 mask)
{
- spin_lock_init(&entry->lock);
- atomic_set(&entry->refcnt, 1);
- INIT_HLIST_NODE(&entry->i_list);
- entry->group = NULL;
- entry->mask = 0;
- entry->inode = NULL;
- entry->free_mark = free_mark;
+ struct inode *inode;
+
+ assert_spin_locked(&mark->lock);
+
+ if (mask &&
+ mark->i.inode &&
+ !(mark->flags & FSNOTIFY_MARK_FLAG_OBJECT_PINNED)) {
+ mark->flags |= FSNOTIFY_MARK_FLAG_OBJECT_PINNED;
+ inode = igrab(mark->i.inode);
+ /*
+ * we shouldn't be able to get here if the inode wasn't
+ * already safely held in memory. But bug in case it
+ * ever is wrong.
+ */
+ BUG_ON(!inode);
+ }
}
/*
- * Attach an initialized mark entry to a given group and inode.
+ * Attach an initialized mark to a given inode.
* These marks may be used for the fsnotify backend to determine which
- * event types should be delivered to which group and for which inodes.
+ * event types should be delivered to which group and for which inodes. These
+ * marks are ordered according to the group's location in memory.
*/
-int fsnotify_add_mark(struct fsnotify_mark_entry *entry,
- struct fsnotify_group *group, struct inode *inode)
+int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
+ struct fsnotify_group *group, struct inode *inode,
+ int allow_dups)
{
- struct fsnotify_mark_entry *lentry;
+ struct fsnotify_mark *lmark;
+ struct hlist_node *node, *last = NULL;
int ret = 0;
- inode = igrab(inode);
- if (unlikely(!inode))
- return -EINVAL;
+ mark->flags |= FSNOTIFY_MARK_FLAG_INODE;
+
+ assert_spin_locked(&mark->lock);
+ assert_spin_locked(&group->mark_lock);
- /*
- * LOCKING ORDER!!!!
- * entry->lock
- * group->mark_lock
- * inode->i_lock
- */
- spin_lock(&entry->lock);
- spin_lock(&group->mark_lock);
spin_lock(&inode->i_lock);
- lentry = fsnotify_find_mark_entry(group, inode);
- if (!lentry) {
- entry->group = group;
- entry->inode = inode;
+ mark->i.inode = inode;
- hlist_add_head(&entry->i_list, &inode->i_fsnotify_mark_entries);
- list_add(&entry->g_list, &group->mark_entries);
+ /* is mark the first mark? */
+ if (hlist_empty(&inode->i_fsnotify_marks)) {
+ hlist_add_head_rcu(&mark->i.i_list, &inode->i_fsnotify_marks);
+ goto out;
+ }
- fsnotify_get_mark(entry); /* for i_list and g_list */
+ /* should mark be in the middle of the current list? */
+ hlist_for_each_entry(lmark, node, &inode->i_fsnotify_marks, i.i_list) {
+ last = node;
+
+ if ((lmark->group == group) && !allow_dups) {
+ ret = -EEXIST;
+ goto out;
+ }
- atomic_inc(&group->num_marks);
+ if (mark->group < lmark->group)
+ continue;
- fsnotify_recalc_inode_mask_locked(inode);
+ hlist_add_before_rcu(&mark->i.i_list, &lmark->i.i_list);
+ goto out;
}
+ BUG_ON(last == NULL);
+ /* mark should be the last entry. last is the current last entry */
+ hlist_add_after_rcu(last, &mark->i.i_list);
+out:
+ fsnotify_recalc_inode_mask_locked(inode);
spin_unlock(&inode->i_lock);
- spin_unlock(&group->mark_lock);
- spin_unlock(&entry->lock);
-
- if (lentry) {
- ret = -EEXIST;
- iput(inode);
- fsnotify_put_mark(lentry);
- } else {
- __fsnotify_update_child_dentry_flags(inode);
- }
return ret;
}
diff --git a/fs/notify/inotify/Kconfig b/fs/notify/inotify/Kconfig
index b3a159b21cfd..b981fc0c8379 100644
--- a/fs/notify/inotify/Kconfig
+++ b/fs/notify/inotify/Kconfig
@@ -1,18 +1,3 @@
-config INOTIFY
- bool "Inotify file change notification support"
- default n
- ---help---
- Say Y here to enable legacy in kernel inotify support. Inotify is a
- file change notification system. It is a replacement for dnotify.
- This option only provides the legacy inotify in kernel API. There
- are no in tree kernel users of this interface since it is deprecated.
- You only need this if you are loading an out of tree kernel module
- that uses inotify.
-
- For more information, see <file:Documentation/filesystems/inotify.txt>
-
- If unsure, say N.
-
config INOTIFY_USER
bool "Inotify support for userspace"
select ANON_INODES
diff --git a/fs/notify/inotify/Makefile b/fs/notify/inotify/Makefile
index 943828171362..a380dabe09de 100644
--- a/fs/notify/inotify/Makefile
+++ b/fs/notify/inotify/Makefile
@@ -1,2 +1 @@
-obj-$(CONFIG_INOTIFY) += inotify.o
obj-$(CONFIG_INOTIFY_USER) += inotify_fsnotify.o inotify_user.o
diff --git a/fs/notify/inotify/inotify.c b/fs/notify/inotify/inotify.c
deleted file mode 100644
index cf6b0429a257..000000000000
--- a/fs/notify/inotify/inotify.c
+++ /dev/null
@@ -1,872 +0,0 @@
-/*
- * fs/inotify.c - inode-based file event notifications
- *
- * Authors:
- * John McCutchan <ttb@tentacle.dhs.org>
- * Robert Love <rml@novell.com>
- *
- * Kernel API added by: Amy Griffis <amy.griffis@hp.com>
- *
- * Copyright (C) 2005 John McCutchan
- * Copyright 2006 Hewlett-Packard Development Company, L.P.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the
- * Free Software Foundation; either version 2, or (at your option) any
- * later version.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- */
-
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/spinlock.h>
-#include <linux/idr.h>
-#include <linux/slab.h>
-#include <linux/fs.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/list.h>
-#include <linux/writeback.h>
-#include <linux/inotify.h>
-#include <linux/fsnotify_backend.h>
-
-static atomic_t inotify_cookie;
-
-/*
- * Lock ordering:
- *
- * dentry->d_lock (used to keep d_move() away from dentry->d_parent)
- * iprune_mutex (synchronize shrink_icache_memory())
- * inode_lock (protects the super_block->s_inodes list)
- * inode->inotify_mutex (protects inode->inotify_watches and watches->i_list)
- * inotify_handle->mutex (protects inotify_handle and watches->h_list)
- *
- * The inode->inotify_mutex and inotify_handle->mutex and held during execution
- * of a caller's event handler. Thus, the caller must not hold any locks
- * taken in their event handler while calling any of the published inotify
- * interfaces.
- */
-
-/*
- * Lifetimes of the three main data structures--inotify_handle, inode, and
- * inotify_watch--are managed by reference count.
- *
- * inotify_handle: Lifetime is from inotify_init() to inotify_destroy().
- * Additional references can bump the count via get_inotify_handle() and drop
- * the count via put_inotify_handle().
- *
- * inotify_watch: for inotify's purposes, lifetime is from inotify_add_watch()
- * to remove_watch_no_event(). Additional references can bump the count via
- * get_inotify_watch() and drop the count via put_inotify_watch(). The caller
- * is reponsible for the final put after receiving IN_IGNORED, or when using
- * IN_ONESHOT after receiving the first event. Inotify does the final put if
- * inotify_destroy() is called.
- *
- * inode: Pinned so long as the inode is associated with a watch, from
- * inotify_add_watch() to the final put_inotify_watch().
- */
-
-/*
- * struct inotify_handle - represents an inotify instance
- *
- * This structure is protected by the mutex 'mutex'.
- */
-struct inotify_handle {
- struct idr idr; /* idr mapping wd -> watch */
- struct mutex mutex; /* protects this bad boy */
- struct list_head watches; /* list of watches */
- atomic_t count; /* reference count */
- u32 last_wd; /* the last wd allocated */
- const struct inotify_operations *in_ops; /* inotify caller operations */
-};
-
-static inline void get_inotify_handle(struct inotify_handle *ih)
-{
- atomic_inc(&ih->count);
-}
-
-static inline void put_inotify_handle(struct inotify_handle *ih)
-{
- if (atomic_dec_and_test(&ih->count)) {
- idr_destroy(&ih->idr);
- kfree(ih);
- }
-}
-
-/**
- * get_inotify_watch - grab a reference to an inotify_watch
- * @watch: watch to grab
- */
-void get_inotify_watch(struct inotify_watch *watch)
-{
- atomic_inc(&watch->count);
-}
-EXPORT_SYMBOL_GPL(get_inotify_watch);
-
-int pin_inotify_watch(struct inotify_watch *watch)
-{
- struct super_block *sb = watch->inode->i_sb;
- if (atomic_inc_not_zero(&sb->s_active)) {
- atomic_inc(&watch->count);
- return 1;
- }
- return 0;
-}
-
-/**
- * put_inotify_watch - decrements the ref count on a given watch. cleans up
- * watch references if the count reaches zero. inotify_watch is freed by
- * inotify callers via the destroy_watch() op.
- * @watch: watch to release
- */
-void put_inotify_watch(struct inotify_watch *watch)
-{
- if (atomic_dec_and_test(&watch->count)) {
- struct inotify_handle *ih = watch->ih;
-
- iput(watch->inode);
- ih->in_ops->destroy_watch(watch);
- put_inotify_handle(ih);
- }
-}
-EXPORT_SYMBOL_GPL(put_inotify_watch);
-
-void unpin_inotify_watch(struct inotify_watch *watch)
-{
- struct super_block *sb = watch->inode->i_sb;
- put_inotify_watch(watch);
- deactivate_super(sb);
-}
-
-/*
- * inotify_handle_get_wd - returns the next WD for use by the given handle
- *
- * Callers must hold ih->mutex. This function can sleep.
- */
-static int inotify_handle_get_wd(struct inotify_handle *ih,
- struct inotify_watch *watch)
-{
- int ret;
-
- do {
- if (unlikely(!idr_pre_get(&ih->idr, GFP_NOFS)))
- return -ENOSPC;
- ret = idr_get_new_above(&ih->idr, watch, ih->last_wd+1, &watch->wd);
- } while (ret == -EAGAIN);
-
- if (likely(!ret))
- ih->last_wd = watch->wd;
-
- return ret;
-}
-
-/*
- * inotify_inode_watched - returns nonzero if there are watches on this inode
- * and zero otherwise. We call this lockless, we do not care if we race.
- */
-static inline int inotify_inode_watched(struct inode *inode)
-{
- return !list_empty(&inode->inotify_watches);
-}
-
-/*
- * Get child dentry flag into synch with parent inode.
- * Flag should always be clear for negative dentrys.
- */
-static void set_dentry_child_flags(struct inode *inode, int watched)
-{
- struct dentry *alias;
-
- spin_lock(&dcache_lock);
- list_for_each_entry(alias, &inode->i_dentry, d_alias) {
- struct dentry *child;
-
- list_for_each_entry(child, &alias->d_subdirs, d_u.d_child) {
- if (!child->d_inode)
- continue;
-
- spin_lock(&child->d_lock);
- if (watched)
- child->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED;
- else
- child->d_flags &=~DCACHE_INOTIFY_PARENT_WATCHED;
- spin_unlock(&child->d_lock);
- }
- }
- spin_unlock(&dcache_lock);
-}
-
-/*
- * inotify_find_handle - find the watch associated with the given inode and
- * handle
- *
- * Callers must hold inode->inotify_mutex.
- */
-static struct inotify_watch *inode_find_handle(struct inode *inode,
- struct inotify_handle *ih)
-{
- struct inotify_watch *watch;
-
- list_for_each_entry(watch, &inode->inotify_watches, i_list) {
- if (watch->ih == ih)
- return watch;
- }
-
- return NULL;
-}
-
-/*
- * remove_watch_no_event - remove watch without the IN_IGNORED event.
- *
- * Callers must hold both inode->inotify_mutex and ih->mutex.
- */
-static void remove_watch_no_event(struct inotify_watch *watch,
- struct inotify_handle *ih)
-{
- list_del(&watch->i_list);
- list_del(&watch->h_list);
-
- if (!inotify_inode_watched(watch->inode))
- set_dentry_child_flags(watch->inode, 0);
-
- idr_remove(&ih->idr, watch->wd);
-}
-
-/**
- * inotify_remove_watch_locked - Remove a watch from both the handle and the
- * inode. Sends the IN_IGNORED event signifying that the inode is no longer
- * watched. May be invoked from a caller's event handler.
- * @ih: inotify handle associated with watch
- * @watch: watch to remove
- *
- * Callers must hold both inode->inotify_mutex and ih->mutex.
- */
-void inotify_remove_watch_locked(struct inotify_handle *ih,
- struct inotify_watch *watch)
-{
- remove_watch_no_event(watch, ih);
- ih->in_ops->handle_event(watch, watch->wd, IN_IGNORED, 0, NULL, NULL);
-}
-EXPORT_SYMBOL_GPL(inotify_remove_watch_locked);
-
-/* Kernel API for producing events */
-
-/*
- * inotify_d_instantiate - instantiate dcache entry for inode
- */
-void inotify_d_instantiate(struct dentry *entry, struct inode *inode)
-{
- struct dentry *parent;
-
- if (!inode)
- return;
-
- spin_lock(&entry->d_lock);
- parent = entry->d_parent;
- if (parent->d_inode && inotify_inode_watched(parent->d_inode))
- entry->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED;
- spin_unlock(&entry->d_lock);
-}
-
-/*
- * inotify_d_move - dcache entry has been moved
- */
-void inotify_d_move(struct dentry *entry)
-{
- struct dentry *parent;
-
- parent = entry->d_parent;
- if (inotify_inode_watched(parent->d_inode))
- entry->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED;
- else
- entry->d_flags &= ~DCACHE_INOTIFY_PARENT_WATCHED;
-}
-
-/**
- * inotify_inode_queue_event - queue an event to all watches on this inode
- * @inode: inode event is originating from
- * @mask: event mask describing this event
- * @cookie: cookie for synchronization, or zero
- * @name: filename, if any
- * @n_inode: inode associated with name
- */
-void inotify_inode_queue_event(struct inode *inode, u32 mask, u32 cookie,
- const char *name, struct inode *n_inode)
-{
- struct inotify_watch *watch, *next;
-
- if (!inotify_inode_watched(inode))
- return;
-
- mutex_lock(&inode->inotify_mutex);
- list_for_each_entry_safe(watch, next, &inode->inotify_watches, i_list) {
- u32 watch_mask = watch->mask;
- if (watch_mask & mask) {
- struct inotify_handle *ih= watch->ih;
- mutex_lock(&ih->mutex);
- if (watch_mask & IN_ONESHOT)
- remove_watch_no_event(watch, ih);
- ih->in_ops->handle_event(watch, watch->wd, mask, cookie,
- name, n_inode);
- mutex_unlock(&ih->mutex);
- }
- }
- mutex_unlock(&inode->inotify_mutex);
-}
-EXPORT_SYMBOL_GPL(inotify_inode_queue_event);
-
-/**
- * inotify_dentry_parent_queue_event - queue an event to a dentry's parent
- * @dentry: the dentry in question, we queue against this dentry's parent
- * @mask: event mask describing this event
- * @cookie: cookie for synchronization, or zero
- * @name: filename, if any
- */
-void inotify_dentry_parent_queue_event(struct dentry *dentry, u32 mask,
- u32 cookie, const char *name)
-{
- struct dentry *parent;
- struct inode *inode;
-
- if (!(dentry->d_flags & DCACHE_INOTIFY_PARENT_WATCHED))
- return;
-
- spin_lock(&dentry->d_lock);
- parent = dentry->d_parent;
- inode = parent->d_inode;
-
- if (inotify_inode_watched(inode)) {
- dget(parent);
- spin_unlock(&dentry->d_lock);
- inotify_inode_queue_event(inode, mask, cookie, name,
- dentry->d_inode);
- dput(parent);
- } else
- spin_unlock(&dentry->d_lock);
-}
-EXPORT_SYMBOL_GPL(inotify_dentry_parent_queue_event);
-
-/**
- * inotify_get_cookie - return a unique cookie for use in synchronizing events.
- */
-u32 inotify_get_cookie(void)
-{
- return atomic_inc_return(&inotify_cookie);
-}
-EXPORT_SYMBOL_GPL(inotify_get_cookie);
-
-/**
- * inotify_unmount_inodes - an sb is unmounting. handle any watched inodes.
- * @list: list of inodes being unmounted (sb->s_inodes)
- *
- * Called with inode_lock held, protecting the unmounting super block's list
- * of inodes, and with iprune_mutex held, keeping shrink_icache_memory() at bay.
- * We temporarily drop inode_lock, however, and CAN block.
- */
-void inotify_unmount_inodes(struct list_head *list)
-{
- struct inode *inode, *next_i, *need_iput = NULL;
-
- list_for_each_entry_safe(inode, next_i, list, i_sb_list) {
- struct inotify_watch *watch, *next_w;
- struct inode *need_iput_tmp;
- struct list_head *watches;
-
- /*
- * We cannot __iget() an inode in state I_FREEING,
- * I_WILL_FREE, or I_NEW which is fine because by that point
- * the inode cannot have any associated watches.
- */
- if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
- continue;
-
- /*
- * If i_count is zero, the inode cannot have any watches and
- * doing an __iget/iput with MS_ACTIVE clear would actually
- * evict all inodes with zero i_count from icache which is
- * unnecessarily violent and may in fact be illegal to do.
- */
- if (!atomic_read(&inode->i_count))
- continue;
-
- need_iput_tmp = need_iput;
- need_iput = NULL;
- /* In case inotify_remove_watch_locked() drops a reference. */
- if (inode != need_iput_tmp)
- __iget(inode);
- else
- need_iput_tmp = NULL;
- /* In case the dropping of a reference would nuke next_i. */
- if ((&next_i->i_sb_list != list) &&
- atomic_read(&next_i->i_count) &&
- !(next_i->i_state & (I_FREEING|I_WILL_FREE))) {
- __iget(next_i);
- need_iput = next_i;
- }
-
- /*
- * We can safely drop inode_lock here because we hold
- * references on both inode and next_i. Also no new inodes
- * will be added since the umount has begun. Finally,
- * iprune_mutex keeps shrink_icache_memory() away.
- */
- spin_unlock(&inode_lock);
-
- if (need_iput_tmp)
- iput(need_iput_tmp);
-
- /* for each watch, send IN_UNMOUNT and then remove it */
- mutex_lock(&inode->inotify_mutex);
- watches = &inode->inotify_watches;
- list_for_each_entry_safe(watch, next_w, watches, i_list) {
- struct inotify_handle *ih= watch->ih;
- get_inotify_watch(watch);
- mutex_lock(&ih->mutex);
- ih->in_ops->handle_event(watch, watch->wd, IN_UNMOUNT, 0,
- NULL, NULL);
- inotify_remove_watch_locked(ih, watch);
- mutex_unlock(&ih->mutex);
- put_inotify_watch(watch);
- }
- mutex_unlock(&inode->inotify_mutex);
- iput(inode);
-
- spin_lock(&inode_lock);
- }
-}
-EXPORT_SYMBOL_GPL(inotify_unmount_inodes);
-
-/**
- * inotify_inode_is_dead - an inode has been deleted, cleanup any watches
- * @inode: inode that is about to be removed
- */
-void inotify_inode_is_dead(struct inode *inode)
-{
- struct inotify_watch *watch, *next;
-
- mutex_lock(&inode->inotify_mutex);
- list_for_each_entry_safe(watch, next, &inode->inotify_watches, i_list) {
- struct inotify_handle *ih = watch->ih;
- mutex_lock(&ih->mutex);
- inotify_remove_watch_locked(ih, watch);
- mutex_unlock(&ih->mutex);
- }
- mutex_unlock(&inode->inotify_mutex);
-}
-EXPORT_SYMBOL_GPL(inotify_inode_is_dead);
-
-/* Kernel Consumer API */
-
-/**
- * inotify_init - allocate and initialize an inotify instance
- * @ops: caller's inotify operations
- */
-struct inotify_handle *inotify_init(const struct inotify_operations *ops)
-{
- struct inotify_handle *ih;
-
- ih = kmalloc(sizeof(struct inotify_handle), GFP_KERNEL);
- if (unlikely(!ih))
- return ERR_PTR(-ENOMEM);
-
- idr_init(&ih->idr);
- INIT_LIST_HEAD(&ih->watches);
- mutex_init(&ih->mutex);
- ih->last_wd = 0;
- ih->in_ops = ops;
- atomic_set(&ih->count, 0);
- get_inotify_handle(ih);
-
- return ih;
-}
-EXPORT_SYMBOL_GPL(inotify_init);
-
-/**
- * inotify_init_watch - initialize an inotify watch
- * @watch: watch to initialize
- */
-void inotify_init_watch(struct inotify_watch *watch)
-{
- INIT_LIST_HEAD(&watch->h_list);
- INIT_LIST_HEAD(&watch->i_list);
- atomic_set(&watch->count, 0);
- get_inotify_watch(watch); /* initial get */
-}
-EXPORT_SYMBOL_GPL(inotify_init_watch);
-
-/*
- * Watch removals suck violently. To kick the watch out we need (in this
- * order) inode->inotify_mutex and ih->mutex. That's fine if we have
- * a hold on inode; however, for all other cases we need to make damn sure
- * we don't race with umount. We can *NOT* just grab a reference to a
- * watch - inotify_unmount_inodes() will happily sail past it and we'll end
- * with reference to inode potentially outliving its superblock. Ideally
- * we just want to grab an active reference to superblock if we can; that
- * will make sure we won't go into inotify_umount_inodes() until we are
- * done. Cleanup is just deactivate_super(). However, that leaves a messy
- * case - what if we *are* racing with umount() and active references to
- * superblock can't be acquired anymore? We can bump ->s_count, grab
- * ->s_umount, which will wait until the superblock is shut down and the
- * watch in question is pining for fjords.
- *
- * And yes, this is far beyond mere "not very pretty"; so's the entire
- * concept of inotify to start with.
- */
-
-/**
- * pin_to_kill - pin the watch down for removal
- * @ih: inotify handle
- * @watch: watch to kill
- *
- * Called with ih->mutex held, drops it. Possible return values:
- * 0 - nothing to do, it has died
- * 1 - remove it, drop the reference and deactivate_super()
- */
-static int pin_to_kill(struct inotify_handle *ih, struct inotify_watch *watch)
-{
- struct super_block *sb = watch->inode->i_sb;
-
- if (atomic_inc_not_zero(&sb->s_active)) {
- get_inotify_watch(watch);
- mutex_unlock(&ih->mutex);
- return 1; /* the best outcome */
- }
- spin_lock(&sb_lock);
- sb->s_count++;
- spin_unlock(&sb_lock);
- mutex_unlock(&ih->mutex); /* can't grab ->s_umount under it */
- down_read(&sb->s_umount);
- /* fs is already shut down; the watch is dead */
- drop_super(sb);
- return 0;
-}
-
-static void unpin_and_kill(struct inotify_watch *watch)
-{
- struct super_block *sb = watch->inode->i_sb;
- put_inotify_watch(watch);
- deactivate_super(sb);
-}
-
-/**
- * inotify_destroy - clean up and destroy an inotify instance
- * @ih: inotify handle
- */
-void inotify_destroy(struct inotify_handle *ih)
-{
- /*
- * Destroy all of the watches for this handle. Unfortunately, not very
- * pretty. We cannot do a simple iteration over the list, because we
- * do not know the inode until we iterate to the watch. But we need to
- * hold inode->inotify_mutex before ih->mutex. The following works.
- *
- * AV: it had to become even uglier to start working ;-/
- */
- while (1) {
- struct inotify_watch *watch;
- struct list_head *watches;
- struct super_block *sb;
- struct inode *inode;
-
- mutex_lock(&ih->mutex);
- watches = &ih->watches;
- if (list_empty(watches)) {
- mutex_unlock(&ih->mutex);
- break;
- }
- watch = list_first_entry(watches, struct inotify_watch, h_list);
- sb = watch->inode->i_sb;
- if (!pin_to_kill(ih, watch))
- continue;
-
- inode = watch->inode;
- mutex_lock(&inode->inotify_mutex);
- mutex_lock(&ih->mutex);
-
- /* make sure we didn't race with another list removal */
- if (likely(idr_find(&ih->idr, watch->wd))) {
- remove_watch_no_event(watch, ih);
- put_inotify_watch(watch);
- }
-
- mutex_unlock(&ih->mutex);
- mutex_unlock(&inode->inotify_mutex);
- unpin_and_kill(watch);
- }
-
- /* free this handle: the put matching the get in inotify_init() */
- put_inotify_handle(ih);
-}
-EXPORT_SYMBOL_GPL(inotify_destroy);
-
-/**
- * inotify_find_watch - find an existing watch for an (ih,inode) pair
- * @ih: inotify handle
- * @inode: inode to watch
- * @watchp: pointer to existing inotify_watch
- *
- * Caller must pin given inode (via nameidata).
- */
-s32 inotify_find_watch(struct inotify_handle *ih, struct inode *inode,
- struct inotify_watch **watchp)
-{
- struct inotify_watch *old;
- int ret = -ENOENT;
-
- mutex_lock(&inode->inotify_mutex);
- mutex_lock(&ih->mutex);
-
- old = inode_find_handle(inode, ih);
- if (unlikely(old)) {
- get_inotify_watch(old); /* caller must put watch */
- *watchp = old;
- ret = old->wd;
- }
-
- mutex_unlock(&ih->mutex);
- mutex_unlock(&inode->inotify_mutex);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(inotify_find_watch);
-
-/**
- * inotify_find_update_watch - find and update the mask of an existing watch
- * @ih: inotify handle
- * @inode: inode's watch to update
- * @mask: mask of events to watch
- *
- * Caller must pin given inode (via nameidata).
- */
-s32 inotify_find_update_watch(struct inotify_handle *ih, struct inode *inode,
- u32 mask)
-{
- struct inotify_watch *old;
- int mask_add = 0;
- int ret;
-
- if (mask & IN_MASK_ADD)
- mask_add = 1;
-
- /* don't allow invalid bits: we don't want flags set */
- mask &= IN_ALL_EVENTS | IN_ONESHOT;
- if (unlikely(!mask))
- return -EINVAL;
-
- mutex_lock(&inode->inotify_mutex);
- mutex_lock(&ih->mutex);
-
- /*
- * Handle the case of re-adding a watch on an (inode,ih) pair that we
- * are already watching. We just update the mask and return its wd.
- */
- old = inode_find_handle(inode, ih);
- if (unlikely(!old)) {
- ret = -ENOENT;
- goto out;
- }
-
- if (mask_add)
- old->mask |= mask;
- else
- old->mask = mask;
- ret = old->wd;
-out:
- mutex_unlock(&ih->mutex);
- mutex_unlock(&inode->inotify_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(inotify_find_update_watch);
-
-/**
- * inotify_add_watch - add a watch to an inotify instance
- * @ih: inotify handle
- * @watch: caller allocated watch structure
- * @inode: inode to watch
- * @mask: mask of events to watch
- *
- * Caller must pin given inode (via nameidata).
- * Caller must ensure it only calls inotify_add_watch() once per watch.
- * Calls inotify_handle_get_wd() so may sleep.
- */
-s32 inotify_add_watch(struct inotify_handle *ih, struct inotify_watch *watch,
- struct inode *inode, u32 mask)
-{
- int ret = 0;
- int newly_watched;
-
- /* don't allow invalid bits: we don't want flags set */
- mask &= IN_ALL_EVENTS | IN_ONESHOT;
- if (unlikely(!mask))
- return -EINVAL;
- watch->mask = mask;
-
- mutex_lock(&inode->inotify_mutex);
- mutex_lock(&ih->mutex);
-
- /* Initialize a new watch */
- ret = inotify_handle_get_wd(ih, watch);
- if (unlikely(ret))
- goto out;
- ret = watch->wd;
-
- /* save a reference to handle and bump the count to make it official */
- get_inotify_handle(ih);
- watch->ih = ih;
-
- /*
- * Save a reference to the inode and bump the ref count to make it
- * official. We hold a reference to nameidata, which makes this safe.
- */
- watch->inode = igrab(inode);
-
- /* Add the watch to the handle's and the inode's list */
- newly_watched = !inotify_inode_watched(inode);
- list_add(&watch->h_list, &ih->watches);
- list_add(&watch->i_list, &inode->inotify_watches);
- /*
- * Set child flags _after_ adding the watch, so there is no race
- * windows where newly instantiated children could miss their parent's
- * watched flag.
- */
- if (newly_watched)
- set_dentry_child_flags(inode, 1);
-
-out:
- mutex_unlock(&ih->mutex);
- mutex_unlock(&inode->inotify_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(inotify_add_watch);
-
-/**
- * inotify_clone_watch - put the watch next to existing one
- * @old: already installed watch
- * @new: new watch
- *
- * Caller must hold the inotify_mutex of inode we are dealing with;
- * it is expected to remove the old watch before unlocking the inode.
- */
-s32 inotify_clone_watch(struct inotify_watch *old, struct inotify_watch *new)
-{
- struct inotify_handle *ih = old->ih;
- int ret = 0;
-
- new->mask = old->mask;
- new->ih = ih;
-
- mutex_lock(&ih->mutex);
-
- /* Initialize a new watch */
- ret = inotify_handle_get_wd(ih, new);
- if (unlikely(ret))
- goto out;
- ret = new->wd;
-
- get_inotify_handle(ih);
-
- new->inode = igrab(old->inode);
-
- list_add(&new->h_list, &ih->watches);
- list_add(&new->i_list, &old->inode->inotify_watches);
-out:
- mutex_unlock(&ih->mutex);
- return ret;
-}
-
-void inotify_evict_watch(struct inotify_watch *watch)
-{
- get_inotify_watch(watch);
- mutex_lock(&watch->ih->mutex);
- inotify_remove_watch_locked(watch->ih, watch);
- mutex_unlock(&watch->ih->mutex);
-}
-
-/**
- * inotify_rm_wd - remove a watch from an inotify instance
- * @ih: inotify handle
- * @wd: watch descriptor to remove
- *
- * Can sleep.
- */
-int inotify_rm_wd(struct inotify_handle *ih, u32 wd)
-{
- struct inotify_watch *watch;
- struct super_block *sb;
- struct inode *inode;
-
- mutex_lock(&ih->mutex);
- watch = idr_find(&ih->idr, wd);
- if (unlikely(!watch)) {
- mutex_unlock(&ih->mutex);
- return -EINVAL;
- }
- sb = watch->inode->i_sb;
- if (!pin_to_kill(ih, watch))
- return 0;
-
- inode = watch->inode;
-
- mutex_lock(&inode->inotify_mutex);
- mutex_lock(&ih->mutex);
-
- /* make sure that we did not race */
- if (likely(idr_find(&ih->idr, wd) == watch))
- inotify_remove_watch_locked(ih, watch);
-
- mutex_unlock(&ih->mutex);
- mutex_unlock(&inode->inotify_mutex);
- unpin_and_kill(watch);
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(inotify_rm_wd);
-
-/**
- * inotify_rm_watch - remove a watch from an inotify instance
- * @ih: inotify handle
- * @watch: watch to remove
- *
- * Can sleep.
- */
-int inotify_rm_watch(struct inotify_handle *ih,
- struct inotify_watch *watch)
-{
- return inotify_rm_wd(ih, watch->wd);
-}
-EXPORT_SYMBOL_GPL(inotify_rm_watch);
-
-/*
- * inotify_setup - core initialization function
- */
-static int __init inotify_setup(void)
-{
- BUILD_BUG_ON(IN_ACCESS != FS_ACCESS);
- BUILD_BUG_ON(IN_MODIFY != FS_MODIFY);
- BUILD_BUG_ON(IN_ATTRIB != FS_ATTRIB);
- BUILD_BUG_ON(IN_CLOSE_WRITE != FS_CLOSE_WRITE);
- BUILD_BUG_ON(IN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE);
- BUILD_BUG_ON(IN_OPEN != FS_OPEN);
- BUILD_BUG_ON(IN_MOVED_FROM != FS_MOVED_FROM);
- BUILD_BUG_ON(IN_MOVED_TO != FS_MOVED_TO);
- BUILD_BUG_ON(IN_CREATE != FS_CREATE);
- BUILD_BUG_ON(IN_DELETE != FS_DELETE);
- BUILD_BUG_ON(IN_DELETE_SELF != FS_DELETE_SELF);
- BUILD_BUG_ON(IN_MOVE_SELF != FS_MOVE_SELF);
- BUILD_BUG_ON(IN_Q_OVERFLOW != FS_Q_OVERFLOW);
-
- BUILD_BUG_ON(IN_UNMOUNT != FS_UNMOUNT);
- BUILD_BUG_ON(IN_ISDIR != FS_IN_ISDIR);
- BUILD_BUG_ON(IN_IGNORED != FS_IN_IGNORED);
- BUILD_BUG_ON(IN_ONESHOT != FS_IN_ONESHOT);
-
- atomic_set(&inotify_cookie, 0);
-
- return 0;
-}
-
-module_init(inotify_setup);
diff --git a/fs/notify/inotify/inotify.h b/fs/notify/inotify/inotify.h
index f234f3a4c8ca..b6642e4de4bf 100644
--- a/fs/notify/inotify/inotify.h
+++ b/fs/notify/inotify/inotify.h
@@ -9,13 +9,12 @@ struct inotify_event_private_data {
int wd;
};
-struct inotify_inode_mark_entry {
- /* fsnotify_mark_entry MUST be the first thing */
- struct fsnotify_mark_entry fsn_entry;
+struct inotify_inode_mark {
+ struct fsnotify_mark fsn_mark;
int wd;
};
-extern void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
+extern void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark,
struct fsnotify_group *group);
extern void inotify_free_event_priv(struct fsnotify_event_private_data *event_priv);
diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c
index e27960cd76ab..5e73eeb2c697 100644
--- a/fs/notify/inotify/inotify_fsnotify.c
+++ b/fs/notify/inotify/inotify_fsnotify.c
@@ -22,6 +22,7 @@
* General Public License for more details.
*/
+#include <linux/dcache.h> /* d_unlinked */
#include <linux/fs.h> /* struct inode */
#include <linux/fsnotify_backend.h>
#include <linux/inotify.h>
@@ -32,26 +33,84 @@
#include "inotify.h"
-static int inotify_handle_event(struct fsnotify_group *group, struct fsnotify_event *event)
+/*
+ * Check if 2 events contain the same information. We do not compare private data
+ * but at this moment that isn't a problem for any know fsnotify listeners.
+ */
+static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new)
+{
+ if ((old->mask == new->mask) &&
+ (old->to_tell == new->to_tell) &&
+ (old->data_type == new->data_type) &&
+ (old->name_len == new->name_len)) {
+ switch (old->data_type) {
+ case (FSNOTIFY_EVENT_INODE):
+ /* remember, after old was put on the wait_q we aren't
+ * allowed to look at the inode any more, only thing
+ * left to check was if the file_name is the same */
+ if (!old->name_len ||
+ !strcmp(old->file_name, new->file_name))
+ return true;
+ break;
+ case (FSNOTIFY_EVENT_FILE):
+ if ((old->file->f_path.mnt == new->file->f_path.mnt) &&
+ (old->file->f_path.dentry == new->file->f_path.dentry))
+ return true;
+ break;
+ case (FSNOTIFY_EVENT_NONE):
+ if (old->mask & FS_Q_OVERFLOW)
+ return true;
+ else if (old->mask & FS_IN_IGNORED)
+ return false;
+ return true;
+ };
+ }
+ return false;
+}
+
+static struct fsnotify_event *inotify_merge(struct list_head *list,
+ struct fsnotify_event *event)
{
- struct fsnotify_mark_entry *entry;
- struct inotify_inode_mark_entry *ientry;
+ struct fsnotify_event_holder *last_holder;
+ struct fsnotify_event *last_event;
+
+ /* and the list better be locked by something too */
+ spin_lock(&event->lock);
+
+ last_holder = list_entry(list->prev, struct fsnotify_event_holder, event_list);
+ last_event = last_holder->event;
+ if (event_compare(last_event, event))
+ fsnotify_get_event(last_event);
+ else
+ last_event = NULL;
+
+ spin_unlock(&event->lock);
+
+ return last_event;
+}
+
+static int inotify_handle_event(struct fsnotify_group *group,
+ struct fsnotify_mark *inode_mark,
+ struct fsnotify_mark *vfsmount_mark,
+ struct fsnotify_event *event)
+{
+ struct inotify_inode_mark *i_mark;
struct inode *to_tell;
struct inotify_event_private_data *event_priv;
struct fsnotify_event_private_data *fsn_event_priv;
- int wd, ret;
+ struct fsnotify_event *added_event;
+ int wd, ret = 0;
+
+ BUG_ON(vfsmount_mark);
+
+ pr_debug("%s: group=%p event=%p to_tell=%p mask=%x\n", __func__, group,
+ event, event->to_tell, event->mask);
to_tell = event->to_tell;
- spin_lock(&to_tell->i_lock);
- entry = fsnotify_find_mark_entry(group, to_tell);
- spin_unlock(&to_tell->i_lock);
- /* race with watch removal? We already passes should_send */
- if (unlikely(!entry))
- return 0;
- ientry = container_of(entry, struct inotify_inode_mark_entry,
- fsn_entry);
- wd = ientry->wd;
+ i_mark = container_of(inode_mark, struct inotify_inode_mark,
+ fsn_mark);
+ wd = i_mark->wd;
event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL);
if (unlikely(!event_priv))
@@ -62,48 +121,40 @@ static int inotify_handle_event(struct fsnotify_group *group, struct fsnotify_ev
fsn_event_priv->group = group;
event_priv->wd = wd;
- ret = fsnotify_add_notify_event(group, event, fsn_event_priv);
- if (ret) {
+ added_event = fsnotify_add_notify_event(group, event, fsn_event_priv, inotify_merge);
+ if (added_event) {
inotify_free_event_priv(fsn_event_priv);
- /* EEXIST says we tail matched, EOVERFLOW isn't something
- * to report up the stack. */
- if ((ret == -EEXIST) ||
- (ret == -EOVERFLOW))
- ret = 0;
+ if (!IS_ERR(added_event))
+ fsnotify_put_event(added_event);
+ else
+ ret = PTR_ERR(added_event);
}
- /*
- * If we hold the entry until after the event is on the queue
- * IN_IGNORED won't be able to pass this event in the queue
- */
- fsnotify_put_mark(entry);
+ if (inode_mark->mask & IN_ONESHOT)
+ fsnotify_destroy_mark(inode_mark);
return ret;
}
-static void inotify_freeing_mark(struct fsnotify_mark_entry *entry, struct fsnotify_group *group)
+static void inotify_freeing_mark(struct fsnotify_mark *fsn_mark, struct fsnotify_group *group)
{
- inotify_ignored_and_remove_idr(entry, group);
+ inotify_ignored_and_remove_idr(fsn_mark, group);
}
-static bool inotify_should_send_event(struct fsnotify_group *group, struct inode *inode, __u32 mask)
+static bool inotify_should_send_event(struct fsnotify_group *group, struct inode *inode,
+ struct fsnotify_mark *inode_mark,
+ struct fsnotify_mark *vfsmount_mark,
+ __u32 mask, void *data, int data_type)
{
- struct fsnotify_mark_entry *entry;
- bool send;
-
- spin_lock(&inode->i_lock);
- entry = fsnotify_find_mark_entry(group, inode);
- spin_unlock(&inode->i_lock);
- if (!entry)
- return false;
+ if ((inode_mark->mask & FS_EXCL_UNLINK) &&
+ (data_type == FSNOTIFY_EVENT_FILE)) {
+ struct file *file = data;
- mask = (mask & ~FS_EVENT_ON_CHILD);
- send = (entry->mask & mask);
-
- /* find took a reference */
- fsnotify_put_mark(entry);
+ if (d_unlinked(file->f_path.dentry))
+ return false;
+ }
- return send;
+ return true;
}
/*
@@ -115,18 +166,18 @@ static bool inotify_should_send_event(struct fsnotify_group *group, struct inode
*/
static int idr_callback(int id, void *p, void *data)
{
- struct fsnotify_mark_entry *entry;
- struct inotify_inode_mark_entry *ientry;
+ struct fsnotify_mark *fsn_mark;
+ struct inotify_inode_mark *i_mark;
static bool warned = false;
if (warned)
return 0;
warned = true;
- entry = p;
- ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
+ fsn_mark = p;
+ i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
- WARN(1, "inotify closing but id=%d for entry=%p in group=%p still in "
+ WARN(1, "inotify closing but id=%d for fsn_mark=%p in group=%p still in "
"idr. Probably leaking memory\n", id, p, data);
/*
@@ -135,9 +186,9 @@ static int idr_callback(int id, void *p, void *data)
* out why we got here and the panic is no worse than the original
* BUG() that was here.
*/
- if (entry)
- printk(KERN_WARNING "entry->group=%p inode=%p wd=%d\n",
- entry->group, entry->inode, ientry->wd);
+ if (fsn_mark)
+ printk(KERN_WARNING "fsn_mark->group=%p inode=%p wd=%d\n",
+ fsn_mark->group, fsn_mark->i.inode, i_mark->wd);
return 0;
}
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index e46ca685b9be..bf7f6d776c31 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -46,17 +46,11 @@
/* these are configurable via /proc/sys/fs/inotify/ */
static int inotify_max_user_instances __read_mostly;
static int inotify_max_queued_events __read_mostly;
-int inotify_max_user_watches __read_mostly;
+static int inotify_max_user_watches __read_mostly;
static struct kmem_cache *inotify_inode_mark_cachep __read_mostly;
struct kmem_cache *event_priv_cachep __read_mostly;
-/*
- * When inotify registers a new group it increments this and uses that
- * value as an offset to set the fsnotify group "name" and priority.
- */
-static atomic_t inotify_grp_num;
-
#ifdef CONFIG_SYSCTL
#include <linux/sysctl.h>
@@ -96,11 +90,14 @@ static inline __u32 inotify_arg_to_mask(u32 arg)
{
__u32 mask;
- /* everything should accept their own ignored and cares about children */
- mask = (FS_IN_IGNORED | FS_EVENT_ON_CHILD);
+ /*
+ * everything should accept their own ignored, cares about children,
+ * and should receive events when the inode is unmounted
+ */
+ mask = (FS_IN_IGNORED | FS_EVENT_ON_CHILD | FS_UNMOUNT);
/* mask off the flags used to open the fd */
- mask |= (arg & (IN_ALL_EVENTS | IN_ONESHOT));
+ mask |= (arg & (IN_ALL_EVENTS | IN_ONESHOT | IN_EXCL_UNLINK));
return mask;
}
@@ -144,6 +141,8 @@ static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
event = fsnotify_peek_notify_event(group);
+ pr_debug("%s: group=%p event=%p\n", __func__, group, event);
+
if (event->name_len)
event_size += roundup(event->name_len + 1, event_size);
@@ -173,6 +172,8 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
size_t event_size = sizeof(struct inotify_event);
size_t name_len = 0;
+ pr_debug("%s: group=%p event=%p\n", __func__, group, event);
+
/* we get the inotify watch descriptor from the event private data */
spin_lock(&event->lock);
fsn_priv = fsnotify_remove_priv_from_event(group, event);
@@ -245,6 +246,8 @@ static ssize_t inotify_read(struct file *file, char __user *buf,
kevent = get_one_event(group, count);
mutex_unlock(&group->notification_mutex);
+ pr_debug("%s: group=%p kevent=%p\n", __func__, group, kevent);
+
if (kevent) {
ret = PTR_ERR(kevent);
if (IS_ERR(kevent))
@@ -289,6 +292,8 @@ static int inotify_release(struct inode *ignored, struct file *file)
struct fsnotify_group *group = file->private_data;
struct user_struct *user = group->inotify_data.user;
+ pr_debug("%s: group=%p\n", __func__, group);
+
fsnotify_clear_marks_by_group(group);
/* free this group, matching get was inotify_init->fsnotify_obtain_group */
@@ -312,6 +317,8 @@ static long inotify_ioctl(struct file *file, unsigned int cmd,
group = file->private_data;
p = (void __user *) arg;
+ pr_debug("%s: group=%p cmd=%u\n", __func__, group, cmd);
+
switch (cmd) {
case FIONREAD:
mutex_lock(&group->notification_mutex);
@@ -357,59 +364,159 @@ static int inotify_find_inode(const char __user *dirname, struct path *path, uns
return error;
}
+static int inotify_add_to_idr(struct idr *idr, spinlock_t *idr_lock,
+ int *last_wd,
+ struct inotify_inode_mark *i_mark)
+{
+ int ret;
+
+ do {
+ if (unlikely(!idr_pre_get(idr, GFP_KERNEL)))
+ return -ENOMEM;
+
+ spin_lock(idr_lock);
+ ret = idr_get_new_above(idr, i_mark, *last_wd + 1,
+ &i_mark->wd);
+ /* we added the mark to the idr, take a reference */
+ if (!ret) {
+ *last_wd = i_mark->wd;
+ fsnotify_get_mark(&i_mark->fsn_mark);
+ }
+ spin_unlock(idr_lock);
+ } while (ret == -EAGAIN);
+
+ return ret;
+}
+
+static struct inotify_inode_mark *inotify_idr_find_locked(struct fsnotify_group *group,
+ int wd)
+{
+ struct idr *idr = &group->inotify_data.idr;
+ spinlock_t *idr_lock = &group->inotify_data.idr_lock;
+ struct inotify_inode_mark *i_mark;
+
+ assert_spin_locked(idr_lock);
+
+ i_mark = idr_find(idr, wd);
+ if (i_mark) {
+ struct fsnotify_mark *fsn_mark = &i_mark->fsn_mark;
+
+ fsnotify_get_mark(fsn_mark);
+ /* One ref for being in the idr, one ref we just took */
+ BUG_ON(atomic_read(&fsn_mark->refcnt) < 2);
+ }
+
+ return i_mark;
+}
+
+static struct inotify_inode_mark *inotify_idr_find(struct fsnotify_group *group,
+ int wd)
+{
+ struct inotify_inode_mark *i_mark;
+ spinlock_t *idr_lock = &group->inotify_data.idr_lock;
+
+ spin_lock(idr_lock);
+ i_mark = inotify_idr_find_locked(group, wd);
+ spin_unlock(idr_lock);
+
+ return i_mark;
+}
+
+static void do_inotify_remove_from_idr(struct fsnotify_group *group,
+ struct inotify_inode_mark *i_mark)
+{
+ struct idr *idr = &group->inotify_data.idr;
+ spinlock_t *idr_lock = &group->inotify_data.idr_lock;
+ int wd = i_mark->wd;
+
+ assert_spin_locked(idr_lock);
+
+ idr_remove(idr, wd);
+
+ /* removed from the idr, drop that ref */
+ fsnotify_put_mark(&i_mark->fsn_mark);
+}
+
/*
* Remove the mark from the idr (if present) and drop the reference
* on the mark because it was in the idr.
*/
static void inotify_remove_from_idr(struct fsnotify_group *group,
- struct inotify_inode_mark_entry *ientry)
+ struct inotify_inode_mark *i_mark)
{
- struct idr *idr;
- struct fsnotify_mark_entry *entry;
- struct inotify_inode_mark_entry *found_ientry;
+ spinlock_t *idr_lock = &group->inotify_data.idr_lock;
+ struct inotify_inode_mark *found_i_mark = NULL;
int wd;
- spin_lock(&group->inotify_data.idr_lock);
- idr = &group->inotify_data.idr;
- wd = ientry->wd;
+ spin_lock(idr_lock);
+ wd = i_mark->wd;
- if (wd == -1)
+ /*
+ * does this i_mark think it is in the idr? we shouldn't get called
+ * if it wasn't....
+ */
+ if (wd == -1) {
+ WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p"
+ " i_mark->inode=%p\n", __func__, i_mark, i_mark->wd,
+ i_mark->fsn_mark.group, i_mark->fsn_mark.i.inode);
goto out;
+ }
- entry = idr_find(&group->inotify_data.idr, wd);
- if (unlikely(!entry))
+ /* Lets look in the idr to see if we find it */
+ found_i_mark = inotify_idr_find_locked(group, wd);
+ if (unlikely(!found_i_mark)) {
+ WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p"
+ " i_mark->inode=%p\n", __func__, i_mark, i_mark->wd,
+ i_mark->fsn_mark.group, i_mark->fsn_mark.i.inode);
goto out;
+ }
- found_ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
- if (unlikely(found_ientry != ientry)) {
- /* We found an entry in the idr with the right wd, but it's
- * not the entry we were told to remove. eparis seriously
- * fucked up somewhere. */
- WARN_ON(1);
- ientry->wd = -1;
+ /*
+ * We found an mark in the idr at the right wd, but it's
+ * not the mark we were told to remove. eparis seriously
+ * fucked up somewhere.
+ */
+ if (unlikely(found_i_mark != i_mark)) {
+ WARN_ONCE(1, "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p "
+ "mark->inode=%p found_i_mark=%p found_i_mark->wd=%d "
+ "found_i_mark->group=%p found_i_mark->inode=%p\n",
+ __func__, i_mark, i_mark->wd, i_mark->fsn_mark.group,
+ i_mark->fsn_mark.i.inode, found_i_mark, found_i_mark->wd,
+ found_i_mark->fsn_mark.group,
+ found_i_mark->fsn_mark.i.inode);
goto out;
}
- /* One ref for being in the idr, one ref held by the caller */
- BUG_ON(atomic_read(&entry->refcnt) < 2);
-
- idr_remove(idr, wd);
- ientry->wd = -1;
+ /*
+ * One ref for being in the idr
+ * one ref held by the caller trying to kill us
+ * one ref grabbed by inotify_idr_find
+ */
+ if (unlikely(atomic_read(&i_mark->fsn_mark.refcnt) < 3)) {
+ printk(KERN_ERR "%s: i_mark=%p i_mark->wd=%d i_mark->group=%p"
+ " i_mark->inode=%p\n", __func__, i_mark, i_mark->wd,
+ i_mark->fsn_mark.group, i_mark->fsn_mark.i.inode);
+ /* we can't really recover with bad ref cnting.. */
+ BUG();
+ }
- /* removed from the idr, drop that ref */
- fsnotify_put_mark(entry);
+ do_inotify_remove_from_idr(group, i_mark);
out:
- spin_unlock(&group->inotify_data.idr_lock);
+ /* match the ref taken by inotify_idr_find_locked() */
+ if (found_i_mark)
+ fsnotify_put_mark(&found_i_mark->fsn_mark);
+ i_mark->wd = -1;
+ spin_unlock(idr_lock);
}
/*
* Send IN_IGNORED for this wd, remove this wd from the idr.
*/
-void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
+void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark,
struct fsnotify_group *group)
{
- struct inotify_inode_mark_entry *ientry;
- struct fsnotify_event *ignored_event;
+ struct inotify_inode_mark *i_mark;
+ struct fsnotify_event *ignored_event, *notify_event;
struct inotify_event_private_data *event_priv;
struct fsnotify_event_private_data *fsn_event_priv;
int ret;
@@ -420,7 +527,7 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
if (!ignored_event)
return;
- ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
+ i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
event_priv = kmem_cache_alloc(event_priv_cachep, GFP_NOFS);
if (unlikely(!event_priv))
@@ -429,37 +536,44 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
fsn_event_priv = &event_priv->fsnotify_event_priv_data;
fsn_event_priv->group = group;
- event_priv->wd = ientry->wd;
-
- ret = fsnotify_add_notify_event(group, ignored_event, fsn_event_priv);
- if (ret)
+ event_priv->wd = i_mark->wd;
+
+ notify_event = fsnotify_add_notify_event(group, ignored_event, fsn_event_priv, NULL);
+ if (notify_event) {
+ if (IS_ERR(notify_event))
+ ret = PTR_ERR(notify_event);
+ else
+ fsnotify_put_event(notify_event);
inotify_free_event_priv(fsn_event_priv);
+ }
skip_send_ignore:
/* matches the reference taken when the event was created */
fsnotify_put_event(ignored_event);
- /* remove this entry from the idr */
- inotify_remove_from_idr(group, ientry);
+ /* remove this mark from the idr */
+ inotify_remove_from_idr(group, i_mark);
atomic_dec(&group->inotify_data.user->inotify_watches);
}
/* ding dong the mark is dead */
-static void inotify_free_mark(struct fsnotify_mark_entry *entry)
+static void inotify_free_mark(struct fsnotify_mark *fsn_mark)
{
- struct inotify_inode_mark_entry *ientry = (struct inotify_inode_mark_entry *)entry;
+ struct inotify_inode_mark *i_mark;
+
+ i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
- kmem_cache_free(inotify_inode_mark_cachep, ientry);
+ kmem_cache_free(inotify_inode_mark_cachep, i_mark);
}
static int inotify_update_existing_watch(struct fsnotify_group *group,
struct inode *inode,
u32 arg)
{
- struct fsnotify_mark_entry *entry;
- struct inotify_inode_mark_entry *ientry;
+ struct fsnotify_mark *fsn_mark;
+ struct inotify_inode_mark *i_mark;
__u32 old_mask, new_mask;
__u32 mask;
int add = (arg & IN_MASK_ADD);
@@ -467,52 +581,43 @@ static int inotify_update_existing_watch(struct fsnotify_group *group,
/* don't allow invalid bits: we don't want flags set */
mask = inotify_arg_to_mask(arg);
- if (unlikely(!mask))
+ if (unlikely(!(mask & IN_ALL_EVENTS)))
return -EINVAL;
- spin_lock(&inode->i_lock);
- entry = fsnotify_find_mark_entry(group, inode);
- spin_unlock(&inode->i_lock);
- if (!entry)
+ fsn_mark = fsnotify_find_inode_mark(group, inode);
+ if (!fsn_mark)
return -ENOENT;
- ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
+ i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
- spin_lock(&entry->lock);
+ spin_lock(&fsn_mark->lock);
- old_mask = entry->mask;
- if (add) {
- entry->mask |= mask;
- new_mask = entry->mask;
- } else {
- entry->mask = mask;
- new_mask = entry->mask;
- }
+ old_mask = fsn_mark->mask;
+ if (add)
+ fsnotify_set_mark_mask_locked(fsn_mark, (fsn_mark->mask | mask));
+ else
+ fsnotify_set_mark_mask_locked(fsn_mark, mask);
+ new_mask = fsn_mark->mask;
- spin_unlock(&entry->lock);
+ spin_unlock(&fsn_mark->lock);
if (old_mask != new_mask) {
/* more bits in old than in new? */
int dropped = (old_mask & ~new_mask);
- /* more bits in this entry than the inode's mask? */
+ /* more bits in this fsn_mark than the inode's mask? */
int do_inode = (new_mask & ~inode->i_fsnotify_mask);
- /* more bits in this entry than the group? */
- int do_group = (new_mask & ~group->mask);
- /* update the inode with this new entry */
+ /* update the inode with this new fsn_mark */
if (dropped || do_inode)
fsnotify_recalc_inode_mask(inode);
- /* update the group mask with the new mask */
- if (dropped || do_group)
- fsnotify_recalc_group_mask(group);
}
/* return the wd */
- ret = ientry->wd;
+ ret = i_mark->wd;
- /* match the get from fsnotify_find_mark_entry() */
- fsnotify_put_mark(entry);
+ /* match the get from fsnotify_find_mark() */
+ fsnotify_put_mark(fsn_mark);
return ret;
}
@@ -521,73 +626,51 @@ static int inotify_new_watch(struct fsnotify_group *group,
struct inode *inode,
u32 arg)
{
- struct inotify_inode_mark_entry *tmp_ientry;
+ struct inotify_inode_mark *tmp_i_mark;
__u32 mask;
int ret;
+ struct idr *idr = &group->inotify_data.idr;
+ spinlock_t *idr_lock = &group->inotify_data.idr_lock;
/* don't allow invalid bits: we don't want flags set */
mask = inotify_arg_to_mask(arg);
- if (unlikely(!mask))
+ if (unlikely(!(mask & IN_ALL_EVENTS)))
return -EINVAL;
- tmp_ientry = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);
- if (unlikely(!tmp_ientry))
+ tmp_i_mark = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);
+ if (unlikely(!tmp_i_mark))
return -ENOMEM;
- fsnotify_init_mark(&tmp_ientry->fsn_entry, inotify_free_mark);
- tmp_ientry->fsn_entry.mask = mask;
- tmp_ientry->wd = -1;
+ fsnotify_init_mark(&tmp_i_mark->fsn_mark, inotify_free_mark);
+ tmp_i_mark->fsn_mark.mask = mask;
+ tmp_i_mark->wd = -1;
ret = -ENOSPC;
if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches)
goto out_err;
-retry:
- ret = -ENOMEM;
- if (unlikely(!idr_pre_get(&group->inotify_data.idr, GFP_KERNEL)))
- goto out_err;
- /* we are putting the mark on the idr, take a reference */
- fsnotify_get_mark(&tmp_ientry->fsn_entry);
-
- spin_lock(&group->inotify_data.idr_lock);
- ret = idr_get_new_above(&group->inotify_data.idr, &tmp_ientry->fsn_entry,
- group->inotify_data.last_wd+1,
- &tmp_ientry->wd);
- spin_unlock(&group->inotify_data.idr_lock);
- if (ret) {
- /* we didn't get on the idr, drop the idr reference */
- fsnotify_put_mark(&tmp_ientry->fsn_entry);
-
- /* idr was out of memory allocate and try again */
- if (ret == -EAGAIN)
- goto retry;
+ ret = inotify_add_to_idr(idr, idr_lock, &group->inotify_data.last_wd,
+ tmp_i_mark);
+ if (ret)
goto out_err;
- }
/* we are on the idr, now get on the inode */
- ret = fsnotify_add_mark(&tmp_ientry->fsn_entry, group, inode);
+ ret = fsnotify_add_mark(&tmp_i_mark->fsn_mark, group, inode, NULL, 0);
if (ret) {
/* we failed to get on the inode, get off the idr */
- inotify_remove_from_idr(group, tmp_ientry);
+ inotify_remove_from_idr(group, tmp_i_mark);
goto out_err;
}
- /* update the idr hint, who cares about races, it's just a hint */
- group->inotify_data.last_wd = tmp_ientry->wd;
-
/* increment the number of watches the user has */
atomic_inc(&group->inotify_data.user->inotify_watches);
- /* return the watch descriptor for this new entry */
- ret = tmp_ientry->wd;
-
- /* if this mark added a new event update the group mask */
- if (mask & ~group->mask)
- fsnotify_recalc_group_mask(group);
+ /* return the watch descriptor for this new mark */
+ ret = tmp_i_mark->wd;
out_err:
- /* match the ref from fsnotify_init_markentry() */
- fsnotify_put_mark(&tmp_ientry->fsn_entry);
+ /* match the ref from fsnotify_init_mark() */
+ fsnotify_put_mark(&tmp_i_mark->fsn_mark);
return ret;
}
@@ -616,11 +699,8 @@ retry:
static struct fsnotify_group *inotify_new_group(struct user_struct *user, unsigned int max_events)
{
struct fsnotify_group *group;
- unsigned int grp_num;
- /* fsnotify_obtain_group took a reference to group, we put this when we kill the file in the end */
- grp_num = (INOTIFY_GROUP_NUM - atomic_inc_return(&inotify_grp_num));
- group = fsnotify_obtain_group(grp_num, 0, &inotify_fsnotify_ops);
+ group = fsnotify_alloc_group(&inotify_fsnotify_ops);
if (IS_ERR(group))
return group;
@@ -726,7 +806,7 @@ fput_and_out:
SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd)
{
struct fsnotify_group *group;
- struct fsnotify_mark_entry *entry;
+ struct inotify_inode_mark *i_mark;
struct file *filp;
int ret = 0, fput_needed;
@@ -735,25 +815,23 @@ SYSCALL_DEFINE2(inotify_rm_watch, int, fd, __s32, wd)
return -EBADF;
/* verify that this is indeed an inotify instance */
- if (unlikely(filp->f_op != &inotify_fops)) {
- ret = -EINVAL;
+ ret = -EINVAL;
+ if (unlikely(filp->f_op != &inotify_fops))
goto out;
- }
group = filp->private_data;
- spin_lock(&group->inotify_data.idr_lock);
- entry = idr_find(&group->inotify_data.idr, wd);
- if (unlikely(!entry)) {
- spin_unlock(&group->inotify_data.idr_lock);
- ret = -EINVAL;
+ ret = -EINVAL;
+ i_mark = inotify_idr_find(group, wd);
+ if (unlikely(!i_mark))
goto out;
- }
- fsnotify_get_mark(entry);
- spin_unlock(&group->inotify_data.idr_lock);
- fsnotify_destroy_mark_by_entry(entry);
- fsnotify_put_mark(entry);
+ ret = 0;
+
+ fsnotify_destroy_mark(&i_mark->fsn_mark);
+
+ /* match ref taken by inotify_idr_find */
+ fsnotify_put_mark(&i_mark->fsn_mark);
out:
fput_light(filp, fput_needed);
@@ -767,7 +845,28 @@ out:
*/
static int __init inotify_user_setup(void)
{
- inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark_entry, SLAB_PANIC);
+ BUILD_BUG_ON(IN_ACCESS != FS_ACCESS);
+ BUILD_BUG_ON(IN_MODIFY != FS_MODIFY);
+ BUILD_BUG_ON(IN_ATTRIB != FS_ATTRIB);
+ BUILD_BUG_ON(IN_CLOSE_WRITE != FS_CLOSE_WRITE);
+ BUILD_BUG_ON(IN_CLOSE_NOWRITE != FS_CLOSE_NOWRITE);
+ BUILD_BUG_ON(IN_OPEN != FS_OPEN);
+ BUILD_BUG_ON(IN_MOVED_FROM != FS_MOVED_FROM);
+ BUILD_BUG_ON(IN_MOVED_TO != FS_MOVED_TO);
+ BUILD_BUG_ON(IN_CREATE != FS_CREATE);
+ BUILD_BUG_ON(IN_DELETE != FS_DELETE);
+ BUILD_BUG_ON(IN_DELETE_SELF != FS_DELETE_SELF);
+ BUILD_BUG_ON(IN_MOVE_SELF != FS_MOVE_SELF);
+ BUILD_BUG_ON(IN_UNMOUNT != FS_UNMOUNT);
+ BUILD_BUG_ON(IN_Q_OVERFLOW != FS_Q_OVERFLOW);
+ BUILD_BUG_ON(IN_IGNORED != FS_IN_IGNORED);
+ BUILD_BUG_ON(IN_EXCL_UNLINK != FS_EXCL_UNLINK);
+ BUILD_BUG_ON(IN_ISDIR != FS_IN_ISDIR);
+ BUILD_BUG_ON(IN_ONESHOT != FS_IN_ONESHOT);
+
+ BUG_ON(hweight32(ALL_INOTIFY_BITS) != 21);
+
+ inotify_inode_mark_cachep = KMEM_CACHE(inotify_inode_mark, SLAB_PANIC);
event_priv_cachep = KMEM_CACHE(inotify_event_private_data, SLAB_PANIC);
inotify_max_queued_events = 16384;
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
new file mode 100644
index 000000000000..325185e514bb
--- /dev/null
+++ b/fs/notify/mark.c
@@ -0,0 +1,371 @@
+/*
+ * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/*
+ * fsnotify inode mark locking/lifetime/and refcnting
+ *
+ * REFCNT:
+ * The mark->refcnt tells how many "things" in the kernel currently are
+ * referencing this object. The object typically will live inside the kernel
+ * with a refcnt of 2, one for each list it is on (i_list, g_list). Any task
+ * which can find this object holding the appropriete locks, can take a reference
+ * and the object itself is guarenteed to survive until the reference is dropped.
+ *
+ * LOCKING:
+ * There are 3 spinlocks involved with fsnotify inode marks and they MUST
+ * be taken in order as follows:
+ *
+ * mark->lock
+ * group->mark_lock
+ * inode->i_lock
+ *
+ * mark->lock protects 2 things, mark->group and mark->inode. You must hold
+ * that lock to dereference either of these things (they could be NULL even with
+ * the lock)
+ *
+ * group->mark_lock protects the marks_list anchored inside a given group
+ * and each mark is hooked via the g_list. It also sorta protects the
+ * free_g_list, which when used is anchored by a private list on the stack of the
+ * task which held the group->mark_lock.
+ *
+ * inode->i_lock protects the i_fsnotify_marks list anchored inside a
+ * given inode and each mark is hooked via the i_list. (and sorta the
+ * free_i_list)
+ *
+ *
+ * LIFETIME:
+ * Inode marks survive between when they are added to an inode and when their
+ * refcnt==0.
+ *
+ * The inode mark can be cleared for a number of different reasons including:
+ * - The inode is unlinked for the last time. (fsnotify_inode_remove)
+ * - The inode is being evicted from cache. (fsnotify_inode_delete)
+ * - The fs the inode is on is unmounted. (fsnotify_inode_delete/fsnotify_unmount_inodes)
+ * - Something explicitly requests that it be removed. (fsnotify_destroy_mark)
+ * - The fsnotify_group associated with the mark is going away and all such marks
+ * need to be cleaned up. (fsnotify_clear_marks_by_group)
+ *
+ * Worst case we are given an inode and need to clean up all the marks on that
+ * inode. We take i_lock and walk the i_fsnotify_marks safely. For each
+ * mark on the list we take a reference (so the mark can't disappear under us).
+ * We remove that mark form the inode's list of marks and we add this mark to a
+ * private list anchored on the stack using i_free_list; At this point we no
+ * longer fear anything finding the mark using the inode's list of marks.
+ *
+ * We can safely and locklessly run the private list on the stack of everything
+ * we just unattached from the original inode. For each mark on the private list
+ * we grab the mark-> and can thus dereference mark->group and mark->inode. If
+ * we see the group and inode are not NULL we take those locks. Now holding all
+ * 3 locks we can completely remove the mark from other tasks finding it in the
+ * future. Remember, 10 things might already be referencing this mark, but they
+ * better be holding a ref. We drop our reference we took before we unhooked it
+ * from the inode. When the ref hits 0 we can free the mark.
+ *
+ * Very similarly for freeing by group, except we use free_g_list.
+ *
+ * This has the very interesting property of being able to run concurrently with
+ * any (or all) other directions.
+ */
+
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/srcu.h>
+#include <linux/writeback.h> /* for inode_lock */
+
+#include <asm/atomic.h>
+
+#include <linux/fsnotify_backend.h>
+#include "fsnotify.h"
+
+struct srcu_struct fsnotify_mark_srcu;
+static DEFINE_SPINLOCK(destroy_lock);
+static LIST_HEAD(destroy_list);
+static DECLARE_WAIT_QUEUE_HEAD(destroy_waitq);
+
+void fsnotify_get_mark(struct fsnotify_mark *mark)
+{
+ atomic_inc(&mark->refcnt);
+}
+
+void fsnotify_put_mark(struct fsnotify_mark *mark)
+{
+ if (atomic_dec_and_test(&mark->refcnt))
+ mark->free_mark(mark);
+}
+
+/*
+ * Any time a mark is getting freed we end up here.
+ * The caller had better be holding a reference to this mark so we don't actually
+ * do the final put under the mark->lock
+ */
+void fsnotify_destroy_mark(struct fsnotify_mark *mark)
+{
+ struct fsnotify_group *group;
+ struct inode *inode = NULL;
+
+ spin_lock(&mark->lock);
+
+ group = mark->group;
+
+ /* something else already called this function on this mark */
+ if (!(mark->flags & FSNOTIFY_MARK_FLAG_ALIVE)) {
+ spin_unlock(&mark->lock);
+ return;
+ }
+
+ mark->flags &= ~FSNOTIFY_MARK_FLAG_ALIVE;
+
+ /* 1 from caller and 1 for being on i_list/g_list */
+ BUG_ON(atomic_read(&mark->refcnt) < 2);
+
+ spin_lock(&group->mark_lock);
+
+ if (mark->flags & FSNOTIFY_MARK_FLAG_INODE) {
+ inode = mark->i.inode;
+ fsnotify_destroy_inode_mark(mark);
+ } else if (mark->flags & FSNOTIFY_MARK_FLAG_VFSMOUNT)
+ fsnotify_destroy_vfsmount_mark(mark);
+ else
+ BUG();
+
+ list_del_init(&mark->g_list);
+
+ spin_unlock(&group->mark_lock);
+ spin_unlock(&mark->lock);
+
+ spin_lock(&destroy_lock);
+ list_add(&mark->destroy_list, &destroy_list);
+ spin_unlock(&destroy_lock);
+ wake_up(&destroy_waitq);
+
+ /*
+ * Some groups like to know that marks are being freed. This is a
+ * callback to the group function to let it know that this mark
+ * is being freed.
+ */
+ if (group->ops->freeing_mark)
+ group->ops->freeing_mark(mark, group);
+
+ /*
+ * __fsnotify_update_child_dentry_flags(inode);
+ *
+ * I really want to call that, but we can't, we have no idea if the inode
+ * still exists the second we drop the mark->lock.
+ *
+ * The next time an event arrive to this inode from one of it's children
+ * __fsnotify_parent will see that the inode doesn't care about it's
+ * children and will update all of these flags then. So really this
+ * is just a lazy update (and could be a perf win...)
+ */
+
+ if (inode && (mark->flags & FSNOTIFY_MARK_FLAG_OBJECT_PINNED))
+ iput(inode);
+
+ /*
+ * it's possible that this group tried to destroy itself, but this
+ * this mark was simultaneously being freed by inode. If that's the
+ * case, we finish freeing the group here.
+ */
+ if (unlikely(atomic_dec_and_test(&group->num_marks)))
+ fsnotify_final_destroy_group(group);
+}
+
+void fsnotify_set_mark_mask_locked(struct fsnotify_mark *mark, __u32 mask)
+{
+ assert_spin_locked(&mark->lock);
+
+ mark->mask = mask;
+
+ if (mark->flags & FSNOTIFY_MARK_FLAG_INODE)
+ fsnotify_set_inode_mark_mask_locked(mark, mask);
+}
+
+void fsnotify_set_mark_ignored_mask_locked(struct fsnotify_mark *mark, __u32 mask)
+{
+ assert_spin_locked(&mark->lock);
+
+ mark->ignored_mask = mask;
+}
+
+/*
+ * Attach an initialized mark to a given group and fs object.
+ * These marks may be used for the fsnotify backend to determine which
+ * event types should be delivered to which group.
+ */
+int fsnotify_add_mark(struct fsnotify_mark *mark,
+ struct fsnotify_group *group, struct inode *inode,
+ struct vfsmount *mnt, int allow_dups)
+{
+ int ret = 0;
+
+ BUG_ON(inode && mnt);
+ BUG_ON(!inode && !mnt);
+
+ /*
+ * LOCKING ORDER!!!!
+ * mark->lock
+ * group->mark_lock
+ * inode->i_lock
+ */
+ spin_lock(&mark->lock);
+ spin_lock(&group->mark_lock);
+
+ mark->flags |= FSNOTIFY_MARK_FLAG_ALIVE;
+
+ mark->group = group;
+ list_add(&mark->g_list, &group->marks_list);
+ atomic_inc(&group->num_marks);
+ fsnotify_get_mark(mark); /* for i_list and g_list */
+
+ if (inode) {
+ ret = fsnotify_add_inode_mark(mark, group, inode, allow_dups);
+ if (ret)
+ goto err;
+ } else if (mnt) {
+ ret = fsnotify_add_vfsmount_mark(mark, group, mnt, allow_dups);
+ if (ret)
+ goto err;
+ } else {
+ BUG();
+ }
+
+ spin_unlock(&group->mark_lock);
+
+ /* this will pin the object if appropriate */
+ fsnotify_set_mark_mask_locked(mark, mark->mask);
+
+ spin_unlock(&mark->lock);
+
+ if (inode)
+ __fsnotify_update_child_dentry_flags(inode);
+
+ return ret;
+err:
+ mark->flags &= ~FSNOTIFY_MARK_FLAG_ALIVE;
+ list_del_init(&mark->g_list);
+ mark->group = NULL;
+ atomic_dec(&group->num_marks);
+
+ spin_unlock(&group->mark_lock);
+ spin_unlock(&mark->lock);
+
+ spin_lock(&destroy_lock);
+ list_add(&mark->destroy_list, &destroy_list);
+ spin_unlock(&destroy_lock);
+ wake_up(&destroy_waitq);
+
+ return ret;
+}
+
+/*
+ * clear any marks in a group in which mark->flags & flags is true
+ */
+void fsnotify_clear_marks_by_group_flags(struct fsnotify_group *group,
+ unsigned int flags)
+{
+ struct fsnotify_mark *lmark, *mark;
+ LIST_HEAD(free_list);
+
+ spin_lock(&group->mark_lock);
+ list_for_each_entry_safe(mark, lmark, &group->marks_list, g_list) {
+ if (mark->flags & flags) {
+ list_add(&mark->free_g_list, &free_list);
+ list_del_init(&mark->g_list);
+ fsnotify_get_mark(mark);
+ }
+ }
+ spin_unlock(&group->mark_lock);
+
+ list_for_each_entry_safe(mark, lmark, &free_list, free_g_list) {
+ fsnotify_destroy_mark(mark);
+ fsnotify_put_mark(mark);
+ }
+}
+
+/*
+ * Given a group, destroy all of the marks associated with that group.
+ */
+void fsnotify_clear_marks_by_group(struct fsnotify_group *group)
+{
+ fsnotify_clear_marks_by_group_flags(group, (unsigned int)-1);
+}
+
+void fsnotify_duplicate_mark(struct fsnotify_mark *new, struct fsnotify_mark *old)
+{
+ assert_spin_locked(&old->lock);
+ new->i.inode = old->i.inode;
+ new->m.mnt = old->m.mnt;
+ new->group = old->group;
+ new->mask = old->mask;
+ new->free_mark = old->free_mark;
+}
+
+/*
+ * Nothing fancy, just initialize lists and locks and counters.
+ */
+void fsnotify_init_mark(struct fsnotify_mark *mark,
+ void (*free_mark)(struct fsnotify_mark *mark))
+{
+ memset(mark, 0, sizeof(*mark));
+ spin_lock_init(&mark->lock);
+ atomic_set(&mark->refcnt, 1);
+ mark->free_mark = free_mark;
+}
+
+static int fsnotify_mark_destroy(void *ignored)
+{
+ struct fsnotify_mark *mark, *next;
+ LIST_HEAD(private_destroy_list);
+
+ for (;;) {
+ spin_lock(&destroy_lock);
+ /* exchange the list head */
+ list_replace_init(&destroy_list, &private_destroy_list);
+ spin_unlock(&destroy_lock);
+
+ synchronize_srcu(&fsnotify_mark_srcu);
+
+ list_for_each_entry_safe(mark, next, &private_destroy_list, destroy_list) {
+ list_del_init(&mark->destroy_list);
+ fsnotify_put_mark(mark);
+ }
+
+ wait_event_interruptible(destroy_waitq, !list_empty(&destroy_list));
+ }
+
+ return 0;
+}
+
+static int __init fsnotify_mark_init(void)
+{
+ struct task_struct *thread;
+
+ thread = kthread_run(fsnotify_mark_destroy, NULL,
+ "fsnotify_mark");
+ if (IS_ERR(thread))
+ panic("unable to start fsnotify mark destruction thread.");
+
+ return 0;
+}
+device_initcall(fsnotify_mark_init);
diff --git a/fs/notify/notification.c b/fs/notify/notification.c
index b8bf53b4c108..d6c435adc7a2 100644
--- a/fs/notify/notification.c
+++ b/fs/notify/notification.c
@@ -31,6 +31,7 @@
* allocated and used.
*/
+#include <linux/file.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/kernel.h>
@@ -56,7 +57,7 @@ static struct kmem_cache *fsnotify_event_holder_cachep;
* it is needed. It's refcnt is set 1 at kernel init time and will never
* get set to 0 so it will never get 'freed'
*/
-static struct fsnotify_event q_overflow_event;
+static struct fsnotify_event *q_overflow_event;
static atomic_t fsnotify_sync_cookie = ATOMIC_INIT(0);
/**
@@ -87,12 +88,15 @@ void fsnotify_put_event(struct fsnotify_event *event)
return;
if (atomic_dec_and_test(&event->refcnt)) {
- if (event->data_type == FSNOTIFY_EVENT_PATH)
- path_put(&event->path);
+ pr_debug("%s: event=%p\n", __func__, event);
+
+ if (event->data_type == FSNOTIFY_EVENT_FILE)
+ fput(event->file);
BUG_ON(!list_empty(&event->private_data_list));
kfree(event->file_name);
+ put_pid(event->tgid);
kmem_cache_free(fsnotify_event_cachep, event);
}
}
@@ -104,7 +108,8 @@ struct fsnotify_event_holder *fsnotify_alloc_event_holder(void)
void fsnotify_destroy_event_holder(struct fsnotify_event_holder *holder)
{
- kmem_cache_free(fsnotify_event_holder_cachep, holder);
+ if (holder)
+ kmem_cache_free(fsnotify_event_holder_cachep, holder);
}
/*
@@ -129,53 +134,20 @@ struct fsnotify_event_private_data *fsnotify_remove_priv_from_event(struct fsnot
}
/*
- * Check if 2 events contain the same information. We do not compare private data
- * but at this moment that isn't a problem for any know fsnotify listeners.
- */
-static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new)
-{
- if ((old->mask == new->mask) &&
- (old->to_tell == new->to_tell) &&
- (old->data_type == new->data_type) &&
- (old->name_len == new->name_len)) {
- switch (old->data_type) {
- case (FSNOTIFY_EVENT_INODE):
- /* remember, after old was put on the wait_q we aren't
- * allowed to look at the inode any more, only thing
- * left to check was if the file_name is the same */
- if (!old->name_len ||
- !strcmp(old->file_name, new->file_name))
- return true;
- break;
- case (FSNOTIFY_EVENT_PATH):
- if ((old->path.mnt == new->path.mnt) &&
- (old->path.dentry == new->path.dentry))
- return true;
- break;
- case (FSNOTIFY_EVENT_NONE):
- if (old->mask & FS_Q_OVERFLOW)
- return true;
- else if (old->mask & FS_IN_IGNORED)
- return false;
- return false;
- };
- }
- return false;
-}
-
-/*
* Add an event to the group notification queue. The group can later pull this
* event off the queue to deal with. If the event is successfully added to the
* group's notification queue, a reference is taken on event.
*/
-int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event,
- struct fsnotify_event_private_data *priv)
+struct fsnotify_event *fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_event *event,
+ struct fsnotify_event_private_data *priv,
+ struct fsnotify_event *(*merge)(struct list_head *,
+ struct fsnotify_event *))
{
+ struct fsnotify_event *return_event = NULL;
struct fsnotify_event_holder *holder = NULL;
struct list_head *list = &group->notification_list;
- struct fsnotify_event_holder *last_holder;
- struct fsnotify_event *last_event;
- int ret = 0;
+
+ pr_debug("%s: group=%p event=%p priv=%p\n", __func__, group, event, priv);
/*
* There is one fsnotify_event_holder embedded inside each fsnotify_event.
@@ -189,18 +161,40 @@ int fsnotify_add_notify_event(struct fsnotify_group *group, struct fsnotify_even
alloc_holder:
holder = fsnotify_alloc_event_holder();
if (!holder)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
}
mutex_lock(&group->notification_mutex);
if (group->q_len >= group->max_events) {
- event = &q_overflow_event;
- ret = -EOVERFLOW;
+ event = q_overflow_event;
+
+ /*
+ * we need to return the overflow event
+ * which means we need a ref
+ */
+ fsnotify_get_event(event);
+ return_event = event;
+
/* sorry, no private data on the overflow event */
priv = NULL;
}
+ if (!list_empty(list) && merge) {
+ struct fsnotify_event *tmp;
+
+ tmp = merge(list, event);
+ if (tmp) {
+ mutex_unlock(&group->notification_mutex);
+
+ if (return_event)
+ fsnotify_put_event(return_event);
+ if (holder != &event->holder)
+ fsnotify_destroy_event_holder(holder);
+ return tmp;
+ }
+ }
+
spin_lock(&event->lock);
if (list_empty(&event->holder.event_list)) {
@@ -212,19 +206,13 @@ alloc_holder:
* event holder was used, go back and get a new one */
spin_unlock(&event->lock);
mutex_unlock(&group->notification_mutex);
- goto alloc_holder;
- }
- if (!list_empty(list)) {
- last_holder = list_entry(list->prev, struct fsnotify_event_holder, event_list);
- last_event = last_holder->event;
- if (event_compare(last_event, event)) {
- spin_unlock(&event->lock);
- mutex_unlock(&group->notification_mutex);
- if (holder != &event->holder)
- fsnotify_destroy_event_holder(holder);
- return -EEXIST;
+ if (return_event) {
+ fsnotify_put_event(return_event);
+ return_event = NULL;
}
+
+ goto alloc_holder;
}
group->q_len++;
@@ -238,7 +226,7 @@ alloc_holder:
mutex_unlock(&group->notification_mutex);
wake_up(&group->notification_waitq);
- return ret;
+ return return_event;
}
/*
@@ -253,6 +241,8 @@ struct fsnotify_event *fsnotify_remove_notify_event(struct fsnotify_group *group
BUG_ON(!mutex_is_locked(&group->notification_mutex));
+ pr_debug("%s: group=%p\n", __func__, group);
+
holder = list_first_entry(&group->notification_list, struct fsnotify_event_holder, event_list);
event = holder->event;
@@ -314,25 +304,82 @@ void fsnotify_flush_notify(struct fsnotify_group *group)
static void initialize_event(struct fsnotify_event *event)
{
- event->holder.event = NULL;
INIT_LIST_HEAD(&event->holder.event_list);
atomic_set(&event->refcnt, 1);
spin_lock_init(&event->lock);
- event->path.dentry = NULL;
- event->path.mnt = NULL;
- event->inode = NULL;
- event->data_type = FSNOTIFY_EVENT_NONE;
-
INIT_LIST_HEAD(&event->private_data_list);
+}
- event->to_tell = NULL;
+/*
+ * Caller damn well better be holding whatever mutex is protecting the
+ * old_holder->event_list and the new_event must be a clean event which
+ * cannot be found anywhere else in the kernel.
+ */
+int fsnotify_replace_event(struct fsnotify_event_holder *old_holder,
+ struct fsnotify_event *new_event)
+{
+ struct fsnotify_event *old_event = old_holder->event;
+ struct fsnotify_event_holder *new_holder = &new_event->holder;
- event->file_name = NULL;
- event->name_len = 0;
+ enum event_spinlock_class {
+ SPINLOCK_OLD,
+ SPINLOCK_NEW,
+ };
- event->sync_cookie = 0;
+ pr_debug("%s: old_event=%p new_event=%p\n", __func__, old_event, new_event);
+
+ /*
+ * if the new_event's embedded holder is in use someone
+ * screwed up and didn't give us a clean new event.
+ */
+ BUG_ON(!list_empty(&new_holder->event_list));
+
+ spin_lock_nested(&old_event->lock, SPINLOCK_OLD);
+ spin_lock_nested(&new_event->lock, SPINLOCK_NEW);
+
+ new_holder->event = new_event;
+ list_replace_init(&old_holder->event_list, &new_holder->event_list);
+
+ spin_unlock(&new_event->lock);
+ spin_unlock(&old_event->lock);
+
+ /* event == holder means we are referenced through the in event holder */
+ if (old_holder != &old_event->holder)
+ fsnotify_destroy_event_holder(old_holder);
+
+ fsnotify_get_event(new_event); /* on the list take reference */
+ fsnotify_put_event(old_event); /* off the list, drop reference */
+
+ return 0;
+}
+
+struct fsnotify_event *fsnotify_clone_event(struct fsnotify_event *old_event)
+{
+ struct fsnotify_event *event;
+
+ event = kmem_cache_alloc(fsnotify_event_cachep, GFP_KERNEL);
+ if (!event)
+ return NULL;
+
+ pr_debug("%s: old_event=%p new_event=%p\n", __func__, old_event, event);
+
+ memcpy(event, old_event, sizeof(*event));
+ initialize_event(event);
+
+ if (event->name_len) {
+ event->file_name = kstrdup(old_event->file_name, GFP_KERNEL);
+ if (!event->file_name) {
+ kmem_cache_free(fsnotify_event_cachep, event);
+ return NULL;
+ }
+ }
+ event->tgid = get_pid(old_event->tgid);
+ if (event->data_type == FSNOTIFY_EVENT_FILE)
+ get_file(event->file);
+
+ return event;
}
/*
@@ -348,15 +395,18 @@ static void initialize_event(struct fsnotify_event *event)
* @name the filename, if available
*/
struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, void *data,
- int data_type, const char *name, u32 cookie,
- gfp_t gfp)
+ int data_type, const unsigned char *name,
+ u32 cookie, gfp_t gfp)
{
struct fsnotify_event *event;
- event = kmem_cache_alloc(fsnotify_event_cachep, gfp);
+ event = kmem_cache_zalloc(fsnotify_event_cachep, gfp);
if (!event)
return NULL;
+ pr_debug("%s: event=%p to_tell=%p mask=%x data=%p data_type=%d\n",
+ __func__, event, to_tell, mask, data, data_type);
+
initialize_event(event);
if (name) {
@@ -368,35 +418,36 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask,
event->name_len = strlen(event->file_name);
}
+ event->tgid = get_pid(task_tgid(current));
event->sync_cookie = cookie;
event->to_tell = to_tell;
+ event->data_type = data_type;
switch (data_type) {
case FSNOTIFY_EVENT_FILE: {
- struct file *file = data;
- struct path *path = &file->f_path;
- event->path.dentry = path->dentry;
- event->path.mnt = path->mnt;
- path_get(&event->path);
- event->data_type = FSNOTIFY_EVENT_PATH;
- break;
- }
- case FSNOTIFY_EVENT_PATH: {
- struct path *path = data;
- event->path.dentry = path->dentry;
- event->path.mnt = path->mnt;
- path_get(&event->path);
- event->data_type = FSNOTIFY_EVENT_PATH;
+ event->file = data;
+ /*
+ * if this file is about to disappear hold an extra reference
+ * until we return to __fput so we don't have to worry about
+ * future get/put destroying the file under us or generating
+ * additional events. Notice that we change f_mode without
+ * holding f_lock. This is safe since this is the only possible
+ * reference to this object in the kernel (it was about to be
+ * freed, remember?)
+ */
+ if (!atomic_long_read(&event->file->f_count)) {
+ event->file->f_mode |= FMODE_NONOTIFY;
+ get_file(event->file);
+ }
+ get_file(event->file);
break;
}
case FSNOTIFY_EVENT_INODE:
event->inode = data;
- event->data_type = FSNOTIFY_EVENT_INODE;
break;
case FSNOTIFY_EVENT_NONE:
event->inode = NULL;
- event->path.dentry = NULL;
- event->path.mnt = NULL;
+ event->file = NULL;
break;
default:
BUG();
@@ -412,8 +463,11 @@ __init int fsnotify_notification_init(void)
fsnotify_event_cachep = KMEM_CACHE(fsnotify_event, SLAB_PANIC);
fsnotify_event_holder_cachep = KMEM_CACHE(fsnotify_event_holder, SLAB_PANIC);
- initialize_event(&q_overflow_event);
- q_overflow_event.mask = FS_Q_OVERFLOW;
+ q_overflow_event = fsnotify_create_event(NULL, FS_Q_OVERFLOW, NULL,
+ FSNOTIFY_EVENT_NONE, NULL, 0,
+ GFP_KERNEL);
+ if (!q_overflow_event)
+ panic("unable to allocate fsnotify q_overflow_event\n");
return 0;
}
diff --git a/fs/notify/vfsmount_mark.c b/fs/notify/vfsmount_mark.c
new file mode 100644
index 000000000000..56772b578fbd
--- /dev/null
+++ b/fs/notify/vfsmount_mark.c
@@ -0,0 +1,187 @@
+/*
+ * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mount.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/writeback.h> /* for inode_lock */
+
+#include <asm/atomic.h>
+
+#include <linux/fsnotify_backend.h>
+#include "fsnotify.h"
+
+void fsnotify_clear_marks_by_mount(struct vfsmount *mnt)
+{
+ struct fsnotify_mark *mark, *lmark;
+ struct hlist_node *pos, *n;
+ LIST_HEAD(free_list);
+
+ spin_lock(&mnt->mnt_root->d_lock);
+ hlist_for_each_entry_safe(mark, pos, n, &mnt->mnt_fsnotify_marks, m.m_list) {
+ list_add(&mark->m.free_m_list, &free_list);
+ hlist_del_init_rcu(&mark->m.m_list);
+ fsnotify_get_mark(mark);
+ }
+ spin_unlock(&mnt->mnt_root->d_lock);
+
+ list_for_each_entry_safe(mark, lmark, &free_list, m.free_m_list) {
+ fsnotify_destroy_mark(mark);
+ fsnotify_put_mark(mark);
+ }
+}
+
+void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group *group)
+{
+ fsnotify_clear_marks_by_group_flags(group, FSNOTIFY_MARK_FLAG_VFSMOUNT);
+}
+
+/*
+ * Recalculate the mask of events relevant to a given vfsmount locked.
+ */
+static void fsnotify_recalc_vfsmount_mask_locked(struct vfsmount *mnt)
+{
+ struct fsnotify_mark *mark;
+ struct hlist_node *pos;
+ __u32 new_mask = 0;
+
+ assert_spin_locked(&mnt->mnt_root->d_lock);
+
+ hlist_for_each_entry(mark, pos, &mnt->mnt_fsnotify_marks, m.m_list)
+ new_mask |= mark->mask;
+ mnt->mnt_fsnotify_mask = new_mask;
+}
+
+/*
+ * Recalculate the mnt->mnt_fsnotify_mask, or the mask of all FS_* event types
+ * any notifier is interested in hearing for this mount point
+ */
+void fsnotify_recalc_vfsmount_mask(struct vfsmount *mnt)
+{
+ spin_lock(&mnt->mnt_root->d_lock);
+ fsnotify_recalc_vfsmount_mask_locked(mnt);
+ spin_unlock(&mnt->mnt_root->d_lock);
+}
+
+void fsnotify_destroy_vfsmount_mark(struct fsnotify_mark *mark)
+{
+ struct vfsmount *mnt = mark->m.mnt;
+
+ assert_spin_locked(&mark->lock);
+ assert_spin_locked(&mark->group->mark_lock);
+
+ spin_lock(&mnt->mnt_root->d_lock);
+
+ hlist_del_init_rcu(&mark->m.m_list);
+ mark->m.mnt = NULL;
+
+ fsnotify_recalc_vfsmount_mask_locked(mnt);
+
+ spin_unlock(&mnt->mnt_root->d_lock);
+}
+
+static struct fsnotify_mark *fsnotify_find_vfsmount_mark_locked(struct fsnotify_group *group,
+ struct vfsmount *mnt)
+{
+ struct fsnotify_mark *mark;
+ struct hlist_node *pos;
+
+ assert_spin_locked(&mnt->mnt_root->d_lock);
+
+ hlist_for_each_entry(mark, pos, &mnt->mnt_fsnotify_marks, m.m_list) {
+ if (mark->group == group) {
+ fsnotify_get_mark(mark);
+ return mark;
+ }
+ }
+ return NULL;
+}
+
+/*
+ * given a group and vfsmount, find the mark associated with that combination.
+ * if found take a reference to that mark and return it, else return NULL
+ */
+struct fsnotify_mark *fsnotify_find_vfsmount_mark(struct fsnotify_group *group,
+ struct vfsmount *mnt)
+{
+ struct fsnotify_mark *mark;
+
+ spin_lock(&mnt->mnt_root->d_lock);
+ mark = fsnotify_find_vfsmount_mark_locked(group, mnt);
+ spin_unlock(&mnt->mnt_root->d_lock);
+
+ return mark;
+}
+
+/*
+ * Attach an initialized mark to a given group and vfsmount.
+ * These marks may be used for the fsnotify backend to determine which
+ * event types should be delivered to which groups.
+ */
+int fsnotify_add_vfsmount_mark(struct fsnotify_mark *mark,
+ struct fsnotify_group *group, struct vfsmount *mnt,
+ int allow_dups)
+{
+ struct fsnotify_mark *lmark;
+ struct hlist_node *node, *last = NULL;
+ int ret = 0;
+
+ mark->flags |= FSNOTIFY_MARK_FLAG_VFSMOUNT;
+
+ assert_spin_locked(&mark->lock);
+ assert_spin_locked(&group->mark_lock);
+
+ spin_lock(&mnt->mnt_root->d_lock);
+
+ mark->m.mnt = mnt;
+
+ /* is mark the first mark? */
+ if (hlist_empty(&mnt->mnt_fsnotify_marks)) {
+ hlist_add_head_rcu(&mark->m.m_list, &mnt->mnt_fsnotify_marks);
+ goto out;
+ }
+
+ /* should mark be in the middle of the current list? */
+ hlist_for_each_entry(lmark, node, &mnt->mnt_fsnotify_marks, m.m_list) {
+ last = node;
+
+ if ((lmark->group == group) && !allow_dups) {
+ ret = -EEXIST;
+ goto out;
+ }
+
+ if (mark->group < lmark->group)
+ continue;
+
+ hlist_add_before_rcu(&mark->m.m_list, &lmark->m.m_list);
+ goto out;
+ }
+
+ BUG_ON(last == NULL);
+ /* mark should be the last entry. last is the current last entry */
+ hlist_add_after_rcu(last, &mark->m.m_list);
+out:
+ fsnotify_recalc_vfsmount_mask_locked(mnt);
+ spin_unlock(&mnt->mnt_root->d_lock);
+
+ return ret;
+}
diff --git a/fs/open.c b/fs/open.c
index 0d1fa3dc0efb..b715d06fbe36 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -29,6 +29,7 @@
#include <linux/falloc.h>
#include <linux/fs_struct.h>
#include <linux/ima.h>
+#include <linux/dnotify.h>
#include "internal.h"
@@ -887,7 +888,7 @@ long do_sys_open(int dfd, const char __user *filename, int flags, int mode)
put_unused_fd(fd);
fd = PTR_ERR(f);
} else {
- fsnotify_open(f->f_path.dentry);
+ fsnotify_open(f);
fd_install(fd, f);
}
}
diff --git a/fs/read_write.c b/fs/read_write.c
index 9c0485236e68..74e36586e4d3 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -311,7 +311,7 @@ ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
else
ret = do_sync_read(file, buf, count, pos);
if (ret > 0) {
- fsnotify_access(file->f_path.dentry);
+ fsnotify_access(file);
add_rchar(current, ret);
}
inc_syscr(current);
@@ -367,7 +367,7 @@ ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_
else
ret = do_sync_write(file, buf, count, pos);
if (ret > 0) {
- fsnotify_modify(file->f_path.dentry);
+ fsnotify_modify(file);
add_wchar(current, ret);
}
inc_syscw(current);
@@ -675,9 +675,9 @@ out:
kfree(iov);
if ((ret + (type == READ)) > 0) {
if (type == READ)
- fsnotify_access(file->f_path.dentry);
+ fsnotify_access(file);
else
- fsnotify_modify(file->f_path.dentry);
+ fsnotify_modify(file);
}
return ret;
}
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-12-22 03:05:53 +0000