This is a note to let you know that we have just queued up the patch titled
Subject: ext4: fix xattr deadlock
to the 2.6.27-stable tree. Its filename is
ext4-fix-xattr-deadlock.patch
A git repo of this tree can be found at
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
>From tytso@xxxxxxx Wed Dec 3 10:42:04 2008
From: Kalpak Shah <kalpak.shah@xxxxxxx>
Date: Sun, 16 Nov 2008 11:05:31 -0500
Subject: ext4: fix xattr deadlock
To: stable@xxxxxxxxxx
Cc: Kalpak Shah <kalpak.shah@xxxxxxx>, Ext4 Developers List <linux-ext4@xxxxxxxxxxxxxxx>, "Theodore Ts'o" <tytso@xxxxxxx>
Message-ID: <1226851540-8032-12-git-send-email-tytso@xxxxxxx>
From: Kalpak Shah <kalpak.shah@xxxxxxx>
(cherry picked from commit 4d20c685fa365766a8f13584b4c8178a15ab7103)
ext4_xattr_set_handle() eventually ends up calling
ext4_mark_inode_dirty() which tries to expand the inode by shifting
the EAs. This leads to the xattr_sem being downed again and leading
to a deadlock.
This patch makes sure that if ext4_xattr_set_handle() is in the
call-chain, ext4_mark_inode_dirty() will not expand the inode.
Signed-off-by: Kalpak Shah <kalpak.shah@xxxxxxx>
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
fs/ext4/xattr.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -959,6 +959,7 @@ ext4_xattr_set_handle(handle_t *handle,
struct ext4_xattr_block_find bs = {
.s = { .not_found = -ENODATA, },
};
+ unsigned long no_expand;
int error;
if (!name)
@@ -966,6 +967,9 @@ ext4_xattr_set_handle(handle_t *handle,
if (strlen(name) > 255)
return -ERANGE;
down_write(&EXT4_I(inode)->xattr_sem);
+ no_expand = EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND;
+ EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND;
+
error = ext4_get_inode_loc(inode, &is.iloc);
if (error)
goto cleanup;
@@ -1042,6 +1046,8 @@ ext4_xattr_set_handle(handle_t *handle,
cleanup:
brelse(is.iloc.bh);
brelse(bs.bh);
+ if (no_expand == 0)
+ EXT4_I(inode)->i_state &= ~EXT4_STATE_NO_EXPAND;
up_write(&EXT4_I(inode)->xattr_sem);
return error;
}
Patches currently in stable-queue which might be from kalpak.shah@xxxxxxx are
queue-2.6.27/ext4-fix-xattr-deadlock.patch
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