---

yaml
---
r: 359184
b: refs/heads/master
c: ecf3d1f
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4f4a4faddea0fe45bf508e723c3a810c5190ed62
+refs/heads/master: ecf3d1f1aa74da0d632b651a2e05a911f60e92c0

trunk/Documentation/filesystems/Locking

@@ -10,6 +10,7 @@ be able to use diff(1).
 --------------------------- dentry_operations --------------------------
 prototypes:
 	int (*d_revalidate)(struct dentry *, unsigned int);
+	int (*d_weak_revalidate)(struct dentry *, unsigned int);
 	int (*d_hash)(const struct dentry *, const struct inode *,
 			struct qstr *);
 	int (*d_compare)(const struct dentry *, const struct inode *,
@@ -25,6 +26,7 @@ prototypes:
 locking rules:
 		rename_lock	->d_lock	may block	rcu-walk
 d_revalidate:	no		no		yes (ref-walk)	maybe
+d_weak_revalidate:no		no		yes	 	no
 d_hash		no		no		no		maybe
 d_compare:	yes		no		no		maybe
 d_delete:	no		yes		no		no

trunk/Documentation/filesystems/porting

@@ -441,3 +441,7 @@ d_make_root() drops the reference to inode if dentry allocation fails.
 two, it gets "is it an O_EXCL or equivalent?" boolean argument.  Note that
 local filesystems can ignore tha argument - they are guaranteed that the
 object doesn't exist.  It's remote/distributed ones that might care...
+--
+[mandatory]
+	FS_REVAL_DOT is gone; if you used to have it, add ->d_weak_revalidate()
+in your dentry operations instead.

trunk/Documentation/filesystems/vfs.txt

@@ -900,6 +900,7 @@ defined:
 
 struct dentry_operations {
 	int (*d_revalidate)(struct dentry *, unsigned int);
+	int (*d_weak_revalidate)(struct dentry *, unsigned int);
 	int (*d_hash)(const struct dentry *, const struct inode *,
 			struct qstr *);
 	int (*d_compare)(const struct dentry *, const struct inode *,
@@ -915,8 +916,13 @@ struct dentry_operations {
 
   d_revalidate: called when the VFS needs to revalidate a dentry. This
 	is called whenever a name look-up finds a dentry in the
-	dcache. Most filesystems leave this as NULL, because all their
-	dentries in the dcache are valid
+	dcache. Most local filesystems leave this as NULL, because all their
+	dentries in the dcache are valid. Network filesystems are different
+	since things can change on the server without the client necessarily
+	being aware of it.
+
+	This function should return a positive value if the dentry is still
+	valid, and zero or a negative error code if it isn't.
 
 	d_revalidate may be called in rcu-walk mode (flags & LOOKUP_RCU).
 	If in rcu-walk mode, the filesystem must revalidate the dentry without
@@ -927,6 +933,20 @@ struct dentry_operations {
 	If a situation is encountered that rcu-walk cannot handle, return
 	-ECHILD and it will be called again in ref-walk mode.
 
+ d_weak_revalidate: called when the VFS needs to revalidate a "jumped" dentry.
+	This is called when a path-walk ends at dentry that was not acquired by
+	doing a lookup in the parent directory. This includes "/", "." and "..",
+	as well as procfs-style symlinks and mountpoint traversal.
+
+	In this case, we are less concerned with whether the dentry is still
+	fully correct, but rather that the inode is still valid. As with
+	d_revalidate, most local filesystems will set this to NULL since their
+	dcache entries are always valid.
+
+	This function has the same return code semantics as d_revalidate.
+
+	d_weak_revalidate is only called after leaving rcu-walk mode.
+
   d_hash: called when the VFS adds a dentry to the hash table. The first
 	dentry passed to d_hash is the parent directory that the name is
 	to be hashed into. The inode is the dentry's inode.

trunk/fs/9p/vfs_dentry.c

@@ -137,6 +137,7 @@ static int v9fs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
 
 const struct dentry_operations v9fs_cached_dentry_operations = {
 	.d_revalidate = v9fs_lookup_revalidate,
+	.d_weak_revalidate = v9fs_lookup_revalidate,
 	.d_delete = v9fs_cached_dentry_delete,
 	.d_release = v9fs_dentry_release,
 };

trunk/fs/9p/vfs_super.c

@@ -363,5 +363,5 @@ struct file_system_type v9fs_fs_type = {
 	.mount = v9fs_mount,
 	.kill_sb = v9fs_kill_super,
 	.owner = THIS_MODULE,
-	.fs_flags = FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT,
+	.fs_flags = FS_RENAME_DOES_D_MOVE,
 };

trunk/fs/dcache.c

@@ -1358,6 +1358,7 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
 	WARN_ON_ONCE(dentry->d_flags & (DCACHE_OP_HASH	|
 				DCACHE_OP_COMPARE	|
 				DCACHE_OP_REVALIDATE	|
+				DCACHE_OP_WEAK_REVALIDATE	|
 				DCACHE_OP_DELETE ));
 	dentry->d_op = op;
 	if (!op)
@@ -1368,6 +1369,8 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op)
 		dentry->d_flags |= DCACHE_OP_COMPARE;
 	if (op->d_revalidate)
 		dentry->d_flags |= DCACHE_OP_REVALIDATE;
+	if (op->d_weak_revalidate)
+		dentry->d_flags |= DCACHE_OP_WEAK_REVALIDATE;
 	if (op->d_delete)
 		dentry->d_flags |= DCACHE_OP_DELETE;
 	if (op->d_prune)

trunk/fs/namei.c

@@ -600,14 +600,10 @@ static int complete_walk(struct nameidata *nd)
 	if (likely(!(nd->flags & LOOKUP_JUMPED)))
 		return 0;
 
-	if (likely(!(dentry->d_flags & DCACHE_OP_REVALIDATE)))
+	if (likely(!(dentry->d_flags & DCACHE_OP_WEAK_REVALIDATE)))
 		return 0;
 
-	if (likely(!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)))
-		return 0;
-
-	/* Note: we do not d_invalidate() */
-	status = d_revalidate(dentry, nd->flags);
+	status = dentry->d_op->d_weak_revalidate(dentry, nd->flags);
 	if (status > 0)
 		return 0;
 

trunk/fs/nfs/dir.c

@@ -1135,6 +1135,45 @@ static int nfs_lookup_revalidate(struct dentry *dentry, unsigned int flags)
 	return error;
 }
 
+/*
+ * A weaker form of d_revalidate for revalidating just the dentry->d_inode
+ * when we don't really care about the dentry name. This is called when a
+ * pathwalk ends on a dentry that was not found via a normal lookup in the
+ * parent dir (e.g.: ".", "..", procfs symlinks or mountpoint traversals).
+ *
+ * In this situation, we just want to verify that the inode itself is OK
+ * since the dentry might have changed on the server.
+ */
+static int nfs_weak_revalidate(struct dentry *dentry, unsigned int flags)
+{
+	int error;
+	struct inode *inode = dentry->d_inode;
+
+	/*
+	 * I believe we can only get a negative dentry here in the case of a
+	 * procfs-style symlink. Just assume it's correct for now, but we may
+	 * eventually need to do something more here.
+	 */
+	if (!inode) {
+		dfprintk(LOOKUPCACHE, "%s: %s/%s has negative inode\n",
+				__func__, dentry->d_parent->d_name.name,
+				dentry->d_name.name);
+		return 1;
+	}
+
+	if (is_bad_inode(inode)) {
+		dfprintk(LOOKUPCACHE, "%s: %s/%s has dud inode\n",
+				__func__, dentry->d_parent->d_name.name,
+				dentry->d_name.name);
+		return 0;
+	}
+
+	error = nfs_revalidate_inode(NFS_SERVER(inode), inode);
+	dfprintk(LOOKUPCACHE, "NFS: %s: inode %lu is %s\n",
+			__func__, inode->i_ino, error ? "invalid" : "valid");
+	return !error;
+}
+
 /*
  * This is called from dput() when d_count is going to 0.
  */
@@ -1202,6 +1241,7 @@ static void nfs_d_release(struct dentry *dentry)
 
 const struct dentry_operations nfs_dentry_operations = {
 	.d_revalidate	= nfs_lookup_revalidate,
+	.d_weak_revalidate	= nfs_weak_revalidate,
 	.d_delete	= nfs_dentry_delete,
 	.d_iput		= nfs_dentry_iput,
 	.d_automount	= nfs_d_automount,

trunk/fs/nfs/nfs4super.c

@@ -28,23 +28,23 @@ static struct file_system_type nfs4_remote_fs_type = {
 	.name		= "nfs4",
 	.mount		= nfs4_remote_mount,
 	.kill_sb	= nfs_kill_super,
-	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 };
 
 static struct file_system_type nfs4_remote_referral_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "nfs4",
 	.mount		= nfs4_remote_referral_mount,
 	.kill_sb	= nfs_kill_super,
-	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 };
 
 struct file_system_type nfs4_referral_fs_type = {
 	.owner		= THIS_MODULE,
 	.name		= "nfs4",
 	.mount		= nfs4_referral_mount,
 	.kill_sb	= nfs_kill_super,
-	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 };
 
 static const struct super_operations nfs4_sops = {

trunk/fs/nfs/super.c

@@ -292,7 +292,7 @@ struct file_system_type nfs_fs_type = {
 	.name		= "nfs",
 	.mount		= nfs_fs_mount,
 	.kill_sb	= nfs_kill_super,
-	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 };
 EXPORT_SYMBOL_GPL(nfs_fs_type);
 
@@ -301,7 +301,7 @@ struct file_system_type nfs_xdev_fs_type = {
 	.name		= "nfs",
 	.mount		= nfs_xdev_mount,
 	.kill_sb	= nfs_kill_super,
-	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 };
 
 const struct super_operations nfs_sops = {
@@ -331,7 +331,7 @@ struct file_system_type nfs4_fs_type = {
 	.name		= "nfs4",
 	.mount		= nfs_fs_mount,
 	.kill_sb	= nfs_kill_super,
-	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
+	.fs_flags	= FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 };
 EXPORT_SYMBOL_GPL(nfs4_fs_type);
 

trunk/include/linux/dcache.h

@@ -145,6 +145,7 @@ enum dentry_d_lock_class
 
 struct dentry_operations {
 	int (*d_revalidate)(struct dentry *, unsigned int);
+	int (*d_weak_revalidate)(struct dentry *, unsigned int);
 	int (*d_hash)(const struct dentry *, const struct inode *,
 			struct qstr *);
 	int (*d_compare)(const struct dentry *, const struct inode *,
@@ -192,6 +193,8 @@ struct dentry_operations {
 #define DCACHE_GENOCIDE		0x0200
 #define DCACHE_SHRINK_LIST	0x0400
 
+#define DCACHE_OP_WEAK_REVALIDATE	0x0800
+
 #define DCACHE_NFSFS_RENAMED	0x1000
      /* this dentry has been "silly renamed" and has to be deleted on the last
       * dput() */

trunk/include/linux/fs.h

@@ -1807,7 +1807,6 @@ struct file_system_type {
 #define FS_HAS_SUBTYPE		4
 #define FS_USERNS_MOUNT		8	/* Can be mounted by userns root */
 #define FS_USERNS_DEV_MOUNT	16 /* A userns mount does not imply MNT_NODEV */
-#define FS_REVAL_DOT		16384	/* Check the paths ".", ".." for staleness */
 #define FS_RENAME_DOES_D_MOVE	32768	/* FS will handle d_move() during rename() internally. */
 	struct dentry *(*mount) (struct file_system_type *, int,
 		       const char *, void *);