The patch titled
autofs4: fix race in unhashed dentry code
has been added to the -mm tree. Its filename is
autofs4-fix-race-in-unhashed-dentry-code.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: autofs4: fix race in unhashed dentry code
From: Jeff Mahoney <jeffm@xxxxxxxx>
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@xxxxxxxx>
Acked-by: Ian Kent <raven@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/autofs4/root.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff -puN fs/autofs4/root.c~autofs4-fix-race-in-unhashed-dentry-code fs/autofs4/root.c
--- a/fs/autofs4/root.c~autofs4-fix-race-in-unhashed-dentry-code
+++ a/fs/autofs4/root.c
@@ -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);
}
}
_
Patches currently in -mm which might be from jeffm@xxxxxxxx are
autofs4-fix-race-in-unhashed-dentry-code.patch
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