diff options
| -rw-r--r-- | fs/namei.c | 35 |
1 files changed, 26 insertions, 9 deletions
diff --git a/fs/namei.c b/fs/namei.c index 2358b326b221..da9c26578663 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -919,12 +919,11 @@ static inline bool managed_dentry_might_block(struct dentry *dentry) } /* - * Skip to top of mountpoint pile in rcuwalk mode. We abort the rcu-walk if we - * meet a managed dentry and we're not walking to "..". True is returned to - * continue, false to abort. + * Try to skip to top of mountpoint pile in rcuwalk mode. Fail if + * we meet a managed dentry that would need blocking. */ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, - struct inode **inode, bool reverse_transit) + struct inode **inode) { for (;;) { struct vfsmount *mounted; @@ -933,8 +932,7 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, * that wants to block transit. */ *inode = path->dentry->d_inode; - if (!reverse_transit && - unlikely(managed_dentry_might_block(path->dentry))) + if (unlikely(managed_dentry_might_block(path->dentry))) return false; if (!d_mountpoint(path->dentry)) @@ -949,10 +947,29 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, } if (unlikely(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT)) - return reverse_transit; + return false; return true; } +static void follow_mount_rcu(struct nameidata *nd, struct path *path, + struct inode **inode) +{ + for (;;) { + struct vfsmount *mounted; + *inode = path->dentry->d_inode; + + if (!d_mountpoint(path->dentry)) + break; + + mounted = __lookup_mnt(path->mnt, path->dentry, 1); + if (!mounted) + break; + path->mnt = mounted; + path->dentry = mounted->mnt_root; + nd->seq = read_seqcount_begin(&path->dentry->d_seq); + } +} + static int follow_dotdot_rcu(struct nameidata *nd) { struct inode *inode = nd->inode; @@ -982,7 +999,7 @@ static int follow_dotdot_rcu(struct nameidata *nd) nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq); inode = nd->path.dentry->d_inode; } - __follow_mount_rcu(nd, &nd->path, &inode, true); + follow_mount_rcu(nd, &nd->path, &inode); nd->inode = inode; return 0; @@ -1157,7 +1174,7 @@ static int do_lookup(struct nameidata *nd, struct qstr *name, } path->mnt = mnt; path->dentry = dentry; - if (likely(__follow_mount_rcu(nd, path, inode, false))) + if (likely(__follow_mount_rcu(nd, path, inode))) return 0; unlazy: if (unlazy_walk(nd, dentry)) |