quota: fix infinite loop
If we fail to start a transaction when releasing dquot, we have to call
dquot_release() anyway to mark dquot structure as inactive. Otherwise we
end in an infinite loop inside dqput().
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: xb <xavier.bru@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 4550b83..3c1397f 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2698,8 +2698,11 @@
handle = ext4_journal_start(dquot_to_inode(dquot),
EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
- if (IS_ERR(handle))
+ if (IS_ERR(handle)) {
+ /* Release dquot anyway to avoid endless cycle in dqput() */
+ dquot_release(dquot);
return PTR_ERR(handle);
+ }
ret = dquot_release(dquot);
err = ext4_journal_stop(handle);
if (!ret)
@@ -2832,6 +2835,12 @@
struct buffer_head *bh;
handle_t *handle = journal_current_handle();
+ if (!handle) {
+ printk(KERN_WARNING "EXT4-fs: Quota write (off=%Lu, len=%Lu)"
+ " cancelled because transaction is not started.\n",
+ (unsigned long long)off, (unsigned long long)len);
+ return -EIO;
+ }
mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
while (towrite > 0) {
tocopy = sb->s_blocksize - offset < towrite ?