lkml.org 
[lkml]   [2007]   [Apr]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] autofs4: fix race in unhashed dentry code
 Commit f50b6f8691cae2e0064c499dd3ef3f31142987f0 introduced a
race in autofs4 between autofs_lookup_unhashed() and
autofs_dentry_release().

autofs_dentry_release() ends up clearing the ->dentry and ->inode
members of autofs_info before removing it from the rehash list. The
list is protected by the rehash lock in both functions, but
since autofs_dentry_release() starts tearing the autofs_info struct
down before removing it from the list, autofs_lookup_unhashed() can
get a autofs_info with a NULL dentry.

This patch moves the clearing of ->dentry and ->inode after the removal
from the rehash list.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>

---

fs/autofs4/root.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/fs/autofs4/root.c 2007-04-11 09:41:44.000000000 -0400
+++ b/fs/autofs4/root.c 2007-04-11 10:54:37.000000000 -0400
@@ -470,9 +470,6 @@ void autofs4_dentry_release(struct dentr
if (inf) {
struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb);

- inf->dentry = NULL;
- inf->inode = NULL;
-
if (sbi) {
spin_lock(&sbi->rehash_lock);
if (!list_empty(&inf->rehash))
@@ -480,6 +477,9 @@ void autofs4_dentry_release(struct dentr
spin_unlock(&sbi->rehash_lock);
}

+ inf->dentry = NULL;
+ inf->inode = NULL;
+
autofs4_free_ino(inf);
}
}
--
Jeff Mahoney
SUSE Labs
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-04-11 17:09    [W:0.042 / U:0.064 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site