diff options
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 3 | ||||
| -rw-r--r-- | fs/namei.c | 27 |
2 files changed, 18 insertions, 12 deletions
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index a1d0d7a3016..61d65cc65c5 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -1053,7 +1053,8 @@ struct dentry_operations { If the 'rcu_walk' parameter is true, then the caller is doing a pathwalk in RCU-walk mode. Sleeping is not permitted in this mode, and the caller can be asked to leave it and call again by returning - -ECHILD. + -ECHILD. -EISDIR may also be returned to tell pathwalk to + ignore d_automount or any mounts. This function is only used if DCACHE_MANAGE_TRANSIT is set on the dentry being transited from. diff --git a/fs/namei.c b/fs/namei.c index 0ff23cecb1b..8a217c48f6d 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1091,10 +1091,10 @@ int follow_down_one(struct path *path) } EXPORT_SYMBOL(follow_down_one); -static inline bool managed_dentry_might_block(struct dentry *dentry) +static inline int managed_dentry_rcu(struct dentry *dentry) { - return (dentry->d_flags & DCACHE_MANAGE_TRANSIT && - dentry->d_op->d_manage(dentry, true) < 0); + return (dentry->d_flags & DCACHE_MANAGE_TRANSIT) ? + dentry->d_op->d_manage(dentry, true) : 0; } /* @@ -1110,11 +1110,18 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, * Don't forget we might have a non-mountpoint managed dentry * that wants to block transit. */ - if (unlikely(managed_dentry_might_block(path->dentry))) + switch (managed_dentry_rcu(path->dentry)) { + case -ECHILD: + default: return false; + case -EISDIR: + return true; + case 0: + break; + } if (!d_mountpoint(path->dentry)) - return true; + return !(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT); mounted = __lookup_mnt(path->mnt, path->dentry); if (!mounted) @@ -1130,7 +1137,8 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, */ *inode = path->dentry->d_inode; } - return read_seqretry(&mount_lock, nd->m_seq); + return read_seqretry(&mount_lock, nd->m_seq) && + !(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT); } static int follow_dotdot_rcu(struct nameidata *nd) @@ -1402,11 +1410,8 @@ static int lookup_fast(struct nameidata *nd, } path->mnt = mnt; path->dentry = dentry; - if (unlikely(!__follow_mount_rcu(nd, path, inode))) - goto unlazy; - if (unlikely(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT)) - goto unlazy; - return 0; + if (likely(__follow_mount_rcu(nd, path, inode))) + return 0; unlazy: if (unlazy_walk(nd, dentry)) return -ECHILD; |