Re: BUG: reiserfs+acl+quota deadlock

[Jan Kara <jack@suse.cz>]

  Hello,

> I've already reported a similiar bug to the one I found now
> and that was fixed by:
> "[PATCH] reiserfs: fix deadlock in inode creation failure path w/
> default ACL"
> 
> This bug is similiar in effect but has some differences in how
> to trigger it. The end effect will be just like with the other
> bug that the affected directory will be unaccessible to any user
> or process.
> 
> So here's the way to reproduce it, as minimal as I could get it:
> 
> You need reiserfs, quota and acl support in kernel.
> you also need quota tools (edquota, quotaon, quotacheck), I used
> linuxquota 3.12.
> 
> # cd /mnt
> # dd if=/dev/zero of=test bs=1M count=50
> 50+0 records in
> 50+0 records out
> # mkreiserfs -f test >/dev/null
> mkreiserfs 3.6.19 (2003 www.namesys.com)
> 
> test is not a block special device
> Continue (y/n):y
> # mkdir mpoint
> # mount test mpoint -o loop,acl,usrquota
> # mkdir mpoint/user1
> # useradd -d /mnt/mpoint/user1 user1     # may also use existing user
> # chown user1 mpoint/user1
> # quotacheck -v mpoint                   # initializes quota file
> # edquota user1
> ---- set soft block limit to 1000, hard limit to 4000 ----
> # edquota -t
> ---- set the grace periods to something small: 1minutes ---
> # quotaon mpoint
> # ## at this point "repquota -a" should show the quota for user1
> # su user1
> # cd
> # ## now we are in user1 home dir as user1
> # cat /dev/zero > file1
> loop2: warning, user block quota exceeded.
> loop2: write failed, user block limit reached.
> cat: write error: No space left on device
> --- now we wait till the grace period expires (repquota -a) ----
> # cat "" > otherfile
> loop2: write failed, user block quota exceeded too long.
> ---- and it will hang forever ----
> # ## /mnt/mpoint can still be accessed, but /mnt/mpoint/user1 can't
> 
> 
> I tested this on an -mm patchset kernel (2.6.13-rc5-mm1), but I
> discovered the bug in my server which runs plain 2.6.12 with the
> patch from Jeff Mahoney for the first reiserfs+acl bug.
> 
> The main difference between the two bugs is that the first one requires
> the existance of a default acl, this one does not, but it does require
> acl to be enabled.
  This seems to be the same problem as bug #4771 that I've just fix. Can
you try attached patch please?
  Andrew, can you include the patch into -mm if ReiserFS guys won't object?

								Honza
-- 
Jan Kara <jack@suse.cz>
SuSE CR Labs

Initialize key object ID in inode so that we don't try to remove the inode
when we fail on some checks even before we manage to allocate something.

Signed-off-by: Jan Kara <jack@suse.cz>

diff -rupX /home/jack/.kerndiffexclude linux-2.6.13-rc6/fs/reiserfs/namei.c linux-2.6.13-rc6-reiser_create_fix/fs/reiserfs/namei.c
--- linux-2.6.13-rc6/fs/reiserfs/namei.c	2005-08-12 10:39:25.000000000 +0200
+++ linux-2.6.13-rc6-reiser_create_fix/fs/reiserfs/namei.c	2005-08-12 10:39:07.000000000 +0200
@@ -593,6 +593,9 @@ static int new_inode_init(struct inode *
 	 */
 	inode->i_uid = current->fsuid;
 	inode->i_mode = mode;
+	/* Make inode invalid - just in case we are going to drop it before
+	 * the initialization happens */
+	INODE_PKEY(inode)->k_objectid = 0;
 
 	if (dir->i_mode & S_ISGID) {
 		inode->i_gid = dir->i_gid;