Merge branch 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin

* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits)
  fs: scale mntget/mntput
  fs: rename vfsmount counter helpers
  fs: implement faster dentry memcmp
  fs: prefetch inode data in dcache lookup
  fs: improve scalability of pseudo filesystems
  fs: dcache per-inode inode alias locking
  fs: dcache per-bucket dcache hash locking
  bit_spinlock: add required includes
  kernel: add bl_list
  xfs: provide simple rcu-walk ACL implementation
  btrfs: provide simple rcu-walk ACL implementation
  ext2,3,4: provide simple rcu-walk ACL implementation
  fs: provide simple rcu-walk generic_check_acl implementation
  fs: provide rcu-walk aware permission i_ops
  fs: rcu-walk aware d_revalidate method
  fs: cache optimise dentry and inode for rcu-walk
  fs: dcache reduce branches in lookup path
  fs: dcache remove d_mounted
  fs: fs_struct use seqlock
  fs: rcu-walk for path lookup
  ...

11 files changed, 89 insertions, 51 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_fs.c b/drivers/infiniband/hw/ipath/ipath_fs.c
index 8c8afc716b98..31ae1b108aea 100644
--- a/drivers/infiniband/hw/ipath/ipath_fs.c
+++ b/drivers/infiniband/hw/ipath/ipath_fs.c
@@ -277,18 +277,14 @@ static int remove_file(struct dentry *parent, char *name)
 		goto bail;
 	}
 
-	spin_lock(&dcache_lock);
 	spin_lock(&tmp->d_lock);
 	if (!(d_unhashed(tmp) && tmp->d_inode)) {
-		dget_locked(tmp);
+		dget_dlock(tmp);
 		__d_drop(tmp);
 		spin_unlock(&tmp->d_lock);
-		spin_unlock(&dcache_lock);
 		simple_unlink(parent->d_inode, tmp);
-	} else {
+	} else
 		spin_unlock(&tmp->d_lock);
-		spin_unlock(&dcache_lock);
-	}
 
 	ret = 0;
 bail:
diff --git a/drivers/infiniband/hw/qib/qib_fs.c b/drivers/infiniband/hw/qib/qib_fs.c
index f99bddc01716..df7fa251dcdc 100644
--- a/drivers/infiniband/hw/qib/qib_fs.c
+++ b/drivers/infiniband/hw/qib/qib_fs.c
@@ -453,17 +453,14 @@ static int remove_file(struct dentry *parent, char *name)
 		goto bail;
 	}
 
-	spin_lock(&dcache_lock);
 	spin_lock(&tmp->d_lock);
 	if (!(d_unhashed(tmp) && tmp->d_inode)) {
-		dget_locked(tmp);
+		dget_dlock(tmp);
 		__d_drop(tmp);
 		spin_unlock(&tmp->d_lock);
-		spin_unlock(&dcache_lock);
 		simple_unlink(parent->d_inode, tmp);
 	} else {
 		spin_unlock(&tmp->d_lock);
-		spin_unlock(&dcache_lock);
 	}
 
 	ret = 0;
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 4759d827e8c7..f511dd15fd31 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -1201,7 +1201,7 @@ err_unregister_chdev:
 static void __exit cleanup_mtdchar(void)
 {
 	unregister_mtd_user(&mtdchar_notifier);
-	mntput(mtd_inode_mnt);
+	mntput_long(mtd_inode_mnt);
 	unregister_filesystem(&mtd_inodefs_type);
 	__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
 }
diff --git a/drivers/staging/autofs/root.c b/drivers/staging/autofs/root.c
index 0fdec4befd84..bf0e9755da67 100644
--- a/drivers/staging/autofs/root.c
+++ b/drivers/staging/autofs/root.c
@@ -154,13 +154,16 @@ static int try_to_fill_dentry(struct dentry *dentry, struct super_block *sb, str
  * yet completely filled in, and revalidate has to delay such
  * lookups..
  */
-static int autofs_revalidate(struct dentry * dentry, struct nameidata *nd)
+static int autofs_revalidate(struct dentry *dentry, struct nameidata *nd)
 {
 	struct inode * dir;
 	struct autofs_sb_info *sbi;
 	struct autofs_dir_ent *ent;
 	int res;
 
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
 	lock_kernel();
 	dir = dentry->d_parent->d_inode;
 	sbi = autofs_sbi(dir->i_sb);
@@ -237,7 +240,7 @@ static struct dentry *autofs_root_lookup(struct inode *dir, struct dentry *dentr
 	 *
 	 * We need to do this before we release the directory semaphore.
 	 */
-	dentry->d_op = &autofs_dentry_operations;
+	d_set_d_op(dentry, &autofs_dentry_operations);
 	dentry->d_flags |= DCACHE_AUTOFS_PENDING;
 	d_add(dentry, NULL);
 
diff --git a/drivers/staging/pohmelfs/inode.c b/drivers/staging/pohmelfs/inode.c
index 61685ccceda8..cc8d2840f9b6 100644
--- a/drivers/staging/pohmelfs/inode.c
+++ b/drivers/staging/pohmelfs/inode.c
@@ -826,6 +826,13 @@ const struct address_space_operations pohmelfs_aops = {
 	.set_page_dirty 	= __set_page_dirty_nobuffers,
 };
 
+static void pohmelfs_i_callback(struct rcu_head *head)
+{
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
+	kmem_cache_free(pohmelfs_inode_cache, POHMELFS_I(inode));
+}
+
 /*
  * ->detroy_inode() callback. Deletes inode from the caches
  *  and frees private data.
@@ -842,8 +849,8 @@ static void pohmelfs_destroy_inode(struct inode *inode)
 
 	dprintk("%s: pi: %p, inode: %p, ino: %llu.\n",
 		__func__, pi, &pi->vfs_inode, pi->ino);
-	kmem_cache_free(pohmelfs_inode_cache, pi);
 	atomic_long_dec(&psb->total_inodes);
+	call_rcu(&inode->i_rcu, pohmelfs_i_callback);
 }
 
 /*
diff --git a/drivers/staging/pohmelfs/path_entry.c b/drivers/staging/pohmelfs/path_entry.c
index 8ec83d2dffb7..400a9fc386ad 100644
--- a/drivers/staging/pohmelfs/path_entry.c
+++ b/drivers/staging/pohmelfs/path_entry.c
@@ -83,10 +83,11 @@ out:
 int pohmelfs_path_length(struct pohmelfs_inode *pi)
 {
 	struct dentry *d, *root, *first;
-	int len = 1; /* Root slash */
+	int len;
+	unsigned seq;
 
-	first = d = d_find_alias(&pi->vfs_inode);
-	if (!d) {
+	first = d_find_alias(&pi->vfs_inode);
+	if (!first) {
 		dprintk("%s: ino: %llu, mode: %o.\n", __func__, pi->ino, pi->vfs_inode.i_mode);
 		return -ENOENT;
 	}
@@ -95,7 +96,11 @@ int pohmelfs_path_length(struct pohmelfs_inode *pi)
 	root = dget(current->fs->root.dentry);
 	spin_unlock(&current->fs->lock);
 
-	spin_lock(&dcache_lock);
+rename_retry:
+	len = 1; /* Root slash */
+	d = first;
+	seq = read_seqbegin(&rename_lock);
+	rcu_read_lock();
 
 	if (!IS_ROOT(d) && d_unhashed(d))
 		len += UNHASHED_OBSCURE_STRING_SIZE; /* Obscure " (deleted)" string */
@@ -104,7 +109,9 @@ int pohmelfs_path_length(struct pohmelfs_inode *pi)
 		len += d->d_name.len + 1; /* Plus slash */
 		d = d->d_parent;
 	}
-	spin_unlock(&dcache_lock);
+	rcu_read_unlock();
+	if (read_seqretry(&rename_lock, seq))
+		goto rename_retry;
 
 	dput(root);
 	dput(first);
diff --git a/drivers/staging/smbfs/cache.c b/drivers/staging/smbfs/cache.c
index dbb98658148b..f2a1323ca827 100644
--- a/drivers/staging/smbfs/cache.c
+++ b/drivers/staging/smbfs/cache.c
@@ -62,7 +62,7 @@ smb_invalidate_dircache_entries(struct dentry *parent)
 	struct list_head *next;
 	struct dentry *dentry;
 
-	spin_lock(&dcache_lock);
+	spin_lock(&parent->d_lock);
 	next = parent->d_subdirs.next;
 	while (next != &parent->d_subdirs) {
 		dentry = list_entry(next, struct dentry, d_u.d_child);
@@ -70,7 +70,7 @@ smb_invalidate_dircache_entries(struct dentry *parent)
 		smb_age_dentry(server, dentry);
 		next = next->next;
 	}
-	spin_unlock(&dcache_lock);
+	spin_unlock(&parent->d_lock);
 }
 
 /*
@@ -96,13 +96,13 @@ smb_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos)
 	}
 
 	/* If a pointer is invalid, we search the dentry. */
-	spin_lock(&dcache_lock);
+	spin_lock(&parent->d_lock);
 	next = parent->d_subdirs.next;
 	while (next != &parent->d_subdirs) {
 		dent = list_entry(next, struct dentry, d_u.d_child);
 		if ((unsigned long)dent->d_fsdata == fpos) {
 			if (dent->d_inode)
-				dget_locked(dent);
+				dget(dent);
 			else
 				dent = NULL;
 			goto out_unlock;
@@ -111,7 +111,7 @@ smb_dget_fpos(struct dentry *dentry, struct dentry *parent, unsigned long fpos)
 	}
 	dent = NULL;
 out_unlock:
-	spin_unlock(&dcache_lock);
+	spin_unlock(&parent->d_lock);
 	return dent;
 }
 
@@ -134,7 +134,7 @@ smb_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
 	qname->hash = full_name_hash(qname->name, qname->len);
 
 	if (dentry->d_op && dentry->d_op->d_hash)
-		if (dentry->d_op->d_hash(dentry, qname) != 0)
+		if (dentry->d_op->d_hash(dentry, inode, qname) != 0)
 			goto end_advance;
 
 	newdent = d_lookup(dentry, qname);
@@ -145,8 +145,8 @@ smb_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
 			goto end_advance;
 	} else {
 		hashed = 1;
-		memcpy((char *) newdent->d_name.name, qname->name,
-		       newdent->d_name.len);
+		/* dir i_mutex is locked because we're in readdir */
+		dentry_update_name_case(newdent, qname);
 	}
 
 	if (!newdent->d_inode) {
diff --git a/drivers/staging/smbfs/dir.c b/drivers/staging/smbfs/dir.c
index f088ea2f6ac9..dd612f50749f 100644
--- a/drivers/staging/smbfs/dir.c
+++ b/drivers/staging/smbfs/dir.c
@@ -14,6 +14,7 @@
 #include <linux/ctype.h>
 #include <linux/net.h>
 #include <linux/sched.h>
+#include <linux/namei.h>
 
 #include "smb_fs.h"
 #include "smb_mount.h"
@@ -274,9 +275,13 @@ smb_dir_open(struct inode *dir, struct file *file)
  * Dentry operations routines
  */
 static int smb_lookup_validate(struct dentry *, struct nameidata *);
-static int smb_hash_dentry(struct dentry *, struct qstr *);
-static int smb_compare_dentry(struct dentry *, struct qstr *, struct qstr *);
-static int smb_delete_dentry(struct dentry *);
+static int smb_hash_dentry(const struct dentry *, const struct inode *,
+		struct qstr *);
+static int smb_compare_dentry(const struct dentry *,
+		const struct inode *,
+		const struct dentry *, const struct inode *,
+		unsigned int, const char *, const struct qstr *);
+static int smb_delete_dentry(const struct dentry *);
 
 static const struct dentry_operations smbfs_dentry_operations =
 {
@@ -297,13 +302,20 @@ static const struct dentry_operations smbfs_dentry_operations_case =
  * This is the callback when the dcache has a lookup hit.
  */
 static int
-smb_lookup_validate(struct dentry * dentry, struct nameidata *nd)
+smb_lookup_validate(struct dentry *dentry, struct nameidata *nd)
 {
-	struct smb_sb_info *server = server_from_dentry(dentry);
-	struct inode * inode = dentry->d_inode;
-	unsigned long age = jiffies - dentry->d_time;
+	struct smb_sb_info *server;
+	struct inode *inode;
+	unsigned long age;
 	int valid;
 
+	if (nd->flags & LOOKUP_RCU)
+		return -ECHILD;
+
+	server = server_from_dentry(dentry);
+	inode = dentry->d_inode;
+	age = jiffies - dentry->d_time;
+
 	/*
 	 * The default validation is based on dentry age:
 	 * we believe in dentries for a few seconds.  (But each
@@ -333,7 +345,8 @@ smb_lookup_validate(struct dentry * dentry, struct nameidata *nd)
 }
 
 static int 
-smb_hash_dentry(struct dentry *dir, struct qstr *this)
+smb_hash_dentry(const struct dentry *dir, const struct inode *inode,
+		struct qstr *this)
 {
 	unsigned long hash;
 	int i;
@@ -347,14 +360,17 @@ smb_hash_dentry(struct dentry *dir, struct qstr *this)
 }
 
 static int
-smb_compare_dentry(struct dentry *dir, struct qstr *a, struct qstr *b)
+smb_compare_dentry(const struct dentry *parent,
+		const struct inode *pinode,
+		const struct dentry *dentry, const struct inode *inode,
+		unsigned int len, const char *str, const struct qstr *name)
 {
 	int i, result = 1;
 
-	if (a->len != b->len)
+	if (len != name->len)
 		goto out;
-	for (i=0; i < a->len; i++) {
-		if (tolower(a->name[i]) != tolower(b->name[i]))
+	for (i=0; i < len; i++) {
+		if (tolower(str[i]) != tolower(name->name[i]))
 			goto out;
 	}
 	result = 0;
@@ -367,7 +383,7 @@ out:
  * We use this to unhash dentries with bad inodes.
  */
 static int
-smb_delete_dentry(struct dentry * dentry)
+smb_delete_dentry(const struct dentry *dentry)
 {
 	if (dentry->d_inode) {
 		if (is_bad_inode(dentry->d_inode)) {
@@ -390,9 +406,9 @@ smb_new_dentry(struct dentry *dentry)
 	struct smb_sb_info *server = server_from_dentry(dentry);
 
 	if (server->mnt->flags & SMB_MOUNT_CASE)
-		dentry->d_op = &smbfs_dentry_operations_case;
+		d_set_d_op(dentry, &smbfs_dentry_operations_case);
 	else
-		dentry->d_op = &smbfs_dentry_operations;
+		d_set_d_op(dentry, &smbfs_dentry_operations);
 	dentry->d_time = jiffies;
 }
 
@@ -454,9 +470,9 @@ smb_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 	add_entry:
 			server = server_from_dentry(dentry);
 			if (server->mnt->flags & SMB_MOUNT_CASE)
-				dentry->d_op = &smbfs_dentry_operations_case;
+				d_set_d_op(dentry, &smbfs_dentry_operations_case);
 			else
-				dentry->d_op = &smbfs_dentry_operations;
+				d_set_d_op(dentry, &smbfs_dentry_operations);
 
 			d_add(dentry, inode);
 			smb_renew_times(dentry);
diff --git a/drivers/staging/smbfs/file.c b/drivers/staging/smbfs/file.c
index 5dcd19c60eb9..31372e7b12de 100644
--- a/drivers/staging/smbfs/file.c
+++ b/drivers/staging/smbfs/file.c
@@ -407,11 +407,14 @@ smb_file_release(struct inode *inode, struct file * file)
  * privileges, so we need our own check for this.
  */
 static int
-smb_file_permission(struct inode *inode, int mask)
+smb_file_permission(struct inode *inode, int mask, unsigned int flags)
 {
 	int mode = inode->i_mode;
 	int error = 0;
 
+	if (flags & IPERM_FLAG_RCU)
+		return -ECHILD;
+
 	VERBOSE("mode=%x, mask=%x\n", mode, mask);
 
 	/* Look at user permissions */
diff --git a/drivers/staging/smbfs/inode.c b/drivers/staging/smbfs/inode.c
index 540a984bb516..244319dc9702 100644
--- a/drivers/staging/smbfs/inode.c
+++ b/drivers/staging/smbfs/inode.c
@@ -62,11 +62,18 @@ static struct inode *smb_alloc_inode(struct super_block *sb)
 	return &ei->vfs_inode;
 }
 
-static void smb_destroy_inode(struct inode *inode)
+static void smb_i_callback(struct rcu_head *head)
 {
+	struct inode *inode = container_of(head, struct inode, i_rcu);
+	INIT_LIST_HEAD(&inode->i_dentry);
 	kmem_cache_free(smb_inode_cachep, SMB_I(inode));
 }
 
+static void smb_destroy_inode(struct inode *inode)
+{
+	call_rcu(&inode->i_rcu, smb_i_callback);
+}
+
 static void init_once(void *foo)
 {
 	struct smb_inode_info *ei = (struct smb_inode_info *) foo;
diff --git a/drivers/usb/core/inode.c b/drivers/usb/core/inode.c
index b690aa35df9a..1b125c224dcf 100644
--- a/drivers/usb/core/inode.c
+++ b/drivers/usb/core/inode.c
@@ -343,17 +343,19 @@ static int usbfs_empty (struct dentry *dentry)
 {
 	struct list_head *list;
 
-	spin_lock(&dcache_lock);
-
+	spin_lock(&dentry->d_lock);
 	list_for_each(list, &dentry->d_subdirs) {
 		struct dentry *de = list_entry(list, struct dentry, d_u.d_child);
+
+		spin_lock_nested(&de->d_lock, DENTRY_D_LOCK_NESTED);
 		if (usbfs_positive(de)) {
-			spin_unlock(&dcache_lock);
+			spin_unlock(&de->d_lock);
+			spin_unlock(&dentry->d_lock);
 			return 0;
 		}
+		spin_unlock(&de->d_lock);
 	}
-
-	spin_unlock(&dcache_lock);
+	spin_unlock(&dentry->d_lock);
 	return 1;
 }