diff options
| author | NeilBrown <neilb@suse.de> | 2014-08-04 17:06:29 +1000 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2014-08-07 14:40:10 -0400 |
| commit | b8faf035ea9d0011b04856a8198e2e212d93346a (patch) | |
| tree | fe06d46ee4a2d659f05740e331a8c823d62d5e3a /Documentation/filesystems | |
| parent | 7c33d5972ce382bcc506d16235f1e9b7d22cbef8 (diff) | |
VFS: allow ->d_manage() to declare -EISDIR in rcu_walk mode.
In REF-walk mode, ->d_manage can return -EISDIR to indicate
that the dentry is not really a mount trap (or even a mount point)
and that any mounts or any DCACHE_NEED_AUTOMOUNT flag should be
ignored.
RCU-walk mode doesn't currently support this, so if there is a dentry
with DCACHE_NEED_AUTOMOUNT set but which shouldn't be a mount-trap,
lookup_fast() will always drop in REF-walk mode.
With this patch, an -EISDIR from ->d_manage will always cause mounts
and automounts to be ignored, both in REF-walk and RCU-walk.
Bug-fixed-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Ian Kent <raven@themaw.net>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 3 |
1 files changed, 2 insertions, 1 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. |