summaryrefslogtreecommitdiff
path: root/fs
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2022-12-12 20:22:09 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-12-12 20:22:09 -0800
commit043930b1c8895d626d340decfe9e418f7233edb8 (patch)
treea13edba88cfd63bce2f5c68f8e39182283a4a8b0 /fs
parent6df7cc2268745e91d090830c58689aa7fcbde6f9 (diff)
parentb138777786f780b9d5ce1989032608acbede0493 (diff)
Merge tag 'fuse-update-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse update from Miklos Szeredi: - Allow some write requests to proceed in parallel - Fix a performance problem with allow_sys_admin_access - Add a special kind of invalidation that doesn't immediately purge submounts - On revalidation treat the target of rename(RENAME_NOREPLACE) the same as open(O_EXCL) - Use type safe helpers for some mnt_userns transformations * tag 'fuse-update-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: Rearrange fuse_allow_current_process checks fuse: allow non-extending parallel direct writes on the same file fuse: remove the unneeded result variable fuse: port to vfs{g,u}id_t and associated helpers fuse: Remove user_ns check for FUSE_DEV_IOC_CLONE fuse: always revalidate rename target dentry fuse: add "expire only" mode to FUSE_NOTIFY_INVAL_ENTRY fs/fuse: Replace kmap() with kmap_local_page()
Diffstat (limited to 'fs')
-rw-r--r--fs/fuse/cuse.c5
-rw-r--r--fs/fuse/dev.c7
-rw-r--r--fs/fuse/dir.c43
-rw-r--r--fs/fuse/file.c43
-rw-r--r--fs/fuse/fuse_i.h4
-rw-r--r--fs/fuse/readdir.c4
6 files changed, 73 insertions, 33 deletions
diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c
index c7d882a9fe33..a06fbb1a8a5b 100644
--- a/fs/fuse/cuse.c
+++ b/fs/fuse/cuse.c
@@ -545,7 +545,6 @@ static int cuse_channel_release(struct inode *inode, struct file *file)
{
struct fuse_dev *fud = file->private_data;
struct cuse_conn *cc = fc_to_cc(fud->fc);
- int rc;
/* remove from the conntbl, no more access from this point on */
mutex_lock(&cuse_lock);
@@ -560,9 +559,7 @@ static int cuse_channel_release(struct inode *inode, struct file *file)
cdev_del(cc->cdev);
}
- rc = fuse_dev_release(inode, file); /* puts the base reference */
-
- return rc;
+ return fuse_dev_release(inode, file);
}
static struct file_operations cuse_channel_fops; /* initialized during init */
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index b4a6e0a1b945..c73d9c4132f6 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1498,7 +1498,7 @@ static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
buf[outarg.namelen] = 0;
down_read(&fc->killsb);
- err = fuse_reverse_inval_entry(fc, outarg.parent, 0, &name);
+ err = fuse_reverse_inval_entry(fc, outarg.parent, 0, &name, outarg.flags);
up_read(&fc->killsb);
kfree(buf);
return err;
@@ -1546,7 +1546,7 @@ static int fuse_notify_delete(struct fuse_conn *fc, unsigned int size,
buf[outarg.namelen] = 0;
down_read(&fc->killsb);
- err = fuse_reverse_inval_entry(fc, outarg.parent, outarg.child, &name);
+ err = fuse_reverse_inval_entry(fc, outarg.parent, outarg.child, &name, 0);
up_read(&fc->killsb);
kfree(buf);
return err;
@@ -2267,8 +2267,7 @@ static long fuse_dev_ioctl(struct file *file, unsigned int cmd,
* Check against file->f_op because CUSE
* uses the same ioctl handler.
*/
- if (old->f_op == file->f_op &&
- old->f_cred->user_ns == file->f_cred->user_ns)
+ if (old->f_op == file->f_op)
fud = fuse_get_dev(old);
if (fud) {
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 25e6b0f7e73d..cd1a071b625a 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -214,7 +214,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
if (inode && fuse_is_bad(inode))
goto invalid;
else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) ||
- (flags & (LOOKUP_EXCL | LOOKUP_REVAL))) {
+ (flags & (LOOKUP_EXCL | LOOKUP_REVAL | LOOKUP_RENAME_TARGET))) {
struct fuse_entry_out outarg;
FUSE_ARGS(args);
struct fuse_forget_link *forget;
@@ -1170,7 +1170,7 @@ int fuse_update_attributes(struct inode *inode, struct file *file, u32 mask)
}
int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
- u64 child_nodeid, struct qstr *name)
+ u64 child_nodeid, struct qstr *name, u32 flags)
{
int err = -ENOTDIR;
struct inode *parent;
@@ -1197,7 +1197,9 @@ int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
goto unlock;
fuse_dir_changed(parent);
- fuse_invalidate_entry(entry);
+ if (!(flags & FUSE_EXPIRE_ONLY))
+ d_invalidate(entry);
+ fuse_invalidate_entry_cache(entry);
if (child_nodeid != 0 && d_really_is_positive(entry)) {
inode_lock(d_inode(entry));
@@ -1235,6 +1237,18 @@ int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
return err;
}
+static inline bool fuse_permissible_uidgid(struct fuse_conn *fc)
+{
+ const struct cred *cred = current_cred();
+
+ return (uid_eq(cred->euid, fc->user_id) &&
+ uid_eq(cred->suid, fc->user_id) &&
+ uid_eq(cred->uid, fc->user_id) &&
+ gid_eq(cred->egid, fc->group_id) &&
+ gid_eq(cred->sgid, fc->group_id) &&
+ gid_eq(cred->gid, fc->group_id));
+}
+
/*
* Calling into a user-controlled filesystem gives the filesystem
* daemon ptrace-like capabilities over the current process. This
@@ -1248,26 +1262,19 @@ int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
* for which the owner of the mount has ptrace privilege. This
* excludes processes started by other users, suid or sgid processes.
*/
-int fuse_allow_current_process(struct fuse_conn *fc)
+bool fuse_allow_current_process(struct fuse_conn *fc)
{
- const struct cred *cred;
-
- if (allow_sys_admin_access && capable(CAP_SYS_ADMIN))
- return 1;
+ bool allow;
if (fc->allow_other)
- return current_in_userns(fc->user_ns);
+ allow = current_in_userns(fc->user_ns);
+ else
+ allow = fuse_permissible_uidgid(fc);
- cred = current_cred();
- if (uid_eq(cred->euid, fc->user_id) &&
- uid_eq(cred->suid, fc->user_id) &&
- uid_eq(cred->uid, fc->user_id) &&
- gid_eq(cred->egid, fc->group_id) &&
- gid_eq(cred->sgid, fc->group_id) &&
- gid_eq(cred->gid, fc->group_id))
- return 1;
+ if (!allow && allow_sys_admin_access && capable(CAP_SYS_ADMIN))
+ allow = true;
- return 0;
+ return allow;
}
static int fuse_access(struct inode *inode, int mask)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index c996c0ef8c63..875314ee6f59 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1563,14 +1563,47 @@ static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to)
return res;
}
+static bool fuse_direct_write_extending_i_size(struct kiocb *iocb,
+ struct iov_iter *iter)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+
+ return iocb->ki_pos + iov_iter_count(iter) > i_size_read(inode);
+}
+
static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct inode *inode = file_inode(iocb->ki_filp);
+ struct file *file = iocb->ki_filp;
+ struct fuse_file *ff = file->private_data;
struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
ssize_t res;
+ bool exclusive_lock =
+ !(ff->open_flags & FOPEN_PARALLEL_DIRECT_WRITES) ||
+ iocb->ki_flags & IOCB_APPEND ||
+ fuse_direct_write_extending_i_size(iocb, from);
+
+ /*
+ * Take exclusive lock if
+ * - Parallel direct writes are disabled - a user space decision
+ * - Parallel direct writes are enabled and i_size is being extended.
+ * This might not be needed at all, but needs further investigation.
+ */
+ if (exclusive_lock)
+ inode_lock(inode);
+ else {
+ inode_lock_shared(inode);
+
+ /* A race with truncate might have come up as the decision for
+ * the lock type was done without holding the lock, check again.
+ */
+ if (fuse_direct_write_extending_i_size(iocb, from)) {
+ inode_unlock_shared(inode);
+ inode_lock(inode);
+ exclusive_lock = true;
+ }
+ }
- /* Don't allow parallel writes to the same file */
- inode_lock(inode);
res = generic_write_checks(iocb, from);
if (res > 0) {
if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) {
@@ -1581,7 +1614,10 @@ static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
fuse_write_update_attr(inode, iocb->ki_pos, res);
}
}
- inode_unlock(inode);
+ if (exclusive_lock)
+ inode_unlock(inode);
+ else
+ inode_unlock_shared(inode);
return res;
}
@@ -2931,6 +2967,7 @@ fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
if (iov_iter_rw(iter) == WRITE) {
fuse_write_update_attr(inode, pos, ret);
+ /* For extending writes we already hold exclusive lock */
if (ret < 0 && offset + count > i_size)
fuse_do_truncate(file);
}
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 26a7c524eb70..c673faefdcb9 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1179,7 +1179,7 @@ bool fuse_invalid_attr(struct fuse_attr *attr);
/**
* Is current process allowed to perform filesystem operation?
*/
-int fuse_allow_current_process(struct fuse_conn *fc);
+bool fuse_allow_current_process(struct fuse_conn *fc);
u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
@@ -1220,7 +1220,7 @@ int fuse_reverse_inval_inode(struct fuse_conn *fc, u64 nodeid,
* then the dentry is unhashed (d_delete()).
*/
int fuse_reverse_inval_entry(struct fuse_conn *fc, u64 parent_nodeid,
- u64 child_nodeid, struct qstr *name);
+ u64 child_nodeid, struct qstr *name, u32 flags);
int fuse_do_open(struct fuse_mount *fm, u64 nodeid, struct file *file,
bool isdir);
diff --git a/fs/fuse/readdir.c b/fs/fuse/readdir.c
index e8deaacf1832..dc603479b30e 100644
--- a/fs/fuse/readdir.c
+++ b/fs/fuse/readdir.c
@@ -547,9 +547,9 @@ retry_locked:
* Contents of the page are now protected against changing by holding
* the page lock.
*/
- addr = kmap(page);
+ addr = kmap_local_page(page);
res = fuse_parse_cache(ff, addr, size, ctx);
- kunmap(page);
+ kunmap_local(addr);
unlock_page(page);
put_page(page);