diff options
| -rw-r--r-- | Documentation/filesystems/Locking | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/porting | 4 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 24 | ||||
| -rw-r--r-- | fs/9p/vfs_dentry.c | 1 | ||||
| -rw-r--r-- | fs/9p/vfs_super.c | 2 | ||||
| -rw-r--r-- | fs/dcache.c | 3 | ||||
| -rw-r--r-- | fs/namei.c | 8 | ||||
| -rw-r--r-- | fs/nfs/dir.c | 40 | ||||
| -rw-r--r-- | fs/nfs/nfs4super.c | 6 | ||||
| -rw-r--r-- | fs/nfs/super.c | 6 | ||||
| -rw-r--r-- | include/linux/dcache.h | 3 | ||||
| -rw-r--r-- | include/linux/fs.h | 1 |
12 files changed, 84 insertions, 16 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index f48e0c6..0706d32 100644 --- a/Documentation/filesystems/Locking +++ b/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 diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 0472c31..4db22f6 100644 --- a/Documentation/filesystems/porting +++ b/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. diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index e3869098..bc4b06b 100644 --- a/Documentation/filesystems/vfs.txt +++ b/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. diff --git a/fs/9p/vfs_dentry.c b/fs/9p/vfs_dentry.c index 64600b5..9ad6862 100644 --- a/fs/9p/vfs_dentry.c +++ b/fs/9p/vfs_dentry.c @@ -137,6 +137,7 @@ out_valid: 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, }; diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c index 137d503..91dad63 100644 --- a/fs/9p/vfs_super.c +++ b/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, }; diff --git a/fs/dcache.c b/fs/dcache.c index ebab049..68220dd 100644 --- a/fs/dcache.c +++ b/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) @@ -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; diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index a8bd28c..f23f455 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -1136,6 +1136,45 @@ out_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. */ static int nfs_dentry_delete(const struct dentry *dentry) @@ -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, diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c index 84d2e9e..569b166 100644 --- a/fs/nfs/nfs4super.c +++ b/fs/nfs/nfs4super.c @@ -28,7 +28,7 @@ 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 = { @@ -36,7 +36,7 @@ static struct file_system_type nfs4_remote_referral_fs_type = { .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 = { @@ -44,7 +44,7 @@ struct file_system_type nfs4_referral_fs_type = { .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 = { diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 2e7e8c8..92acc26 100644 --- a/fs/nfs/super.c +++ b/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); diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 03d1692..1a6bb81f 100644 --- a/include/linux/dcache.h +++ b/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() */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 7f47152..da94011 100644 --- a/include/linux/fs.h +++ b/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 *); |
