summaryrefslogtreecommitdiffstats
path: root/fs/namei.c
diff options
context:
space:
mode:
Diffstat (limited to 'fs/namei.c')
-rw-r--r--fs/namei.c41
1 files changed, 24 insertions, 17 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 2358b326b221..1ab641f2e78e 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))
@@ -947,16 +945,24 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
path->dentry = mounted->mnt_root;
nd->seq = read_seqcount_begin(&path->dentry->d_seq);
}
-
- if (unlikely(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT))
- return reverse_transit;
return true;
}
-static int follow_dotdot_rcu(struct nameidata *nd)
+static void follow_mount_rcu(struct nameidata *nd)
{
- struct inode *inode = nd->inode;
+ while (d_mountpoint(nd->path.dentry)) {
+ struct vfsmount *mounted;
+ mounted = __lookup_mnt(nd->path.mnt, nd->path.dentry, 1);
+ if (!mounted)
+ break;
+ nd->path.mnt = mounted;
+ nd->path.dentry = mounted->mnt_root;
+ nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
+ }
+}
+static int follow_dotdot_rcu(struct nameidata *nd)
+{
set_root_rcu(nd);
while (1) {
@@ -972,7 +978,6 @@ static int follow_dotdot_rcu(struct nameidata *nd)
seq = read_seqcount_begin(&parent->d_seq);
if (read_seqcount_retry(&old->d_seq, nd->seq))
goto failed;
- inode = parent->d_inode;
nd->path.dentry = parent;
nd->seq = seq;
break;
@@ -980,10 +985,9 @@ static int follow_dotdot_rcu(struct nameidata *nd)
if (!follow_up_rcu(&nd->path))
break;
nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
- inode = nd->path.dentry->d_inode;
}
- __follow_mount_rcu(nd, &nd->path, &inode, true);
- nd->inode = inode;
+ follow_mount_rcu(nd);
+ nd->inode = nd->path.dentry->d_inode;
return 0;
failed:
@@ -1157,8 +1161,11 @@ 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)))
- return 0;
+ if (unlikely(!__follow_mount_rcu(nd, path, inode)))
+ goto unlazy;
+ if (unlikely(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT))
+ goto unlazy;
+ return 0;
unlazy:
if (unlazy_walk(nd, dentry))
return -ECHILD;