[PATCH 5.10 640/663] gfs2: Recursive gfs2_quota_hold in gfs2_iomap_end

From: Greg Kroah-Hartman
Date: Mon Mar 01 2021 - 23:43:07 EST


From: Andreas Gruenbacher <agruenba@xxxxxxxxxx>

commit 7009fa9cd9a5262944b30eb7efb1f0561d074b68 upstream.

When starting an iomap write, gfs2_quota_lock_check -> gfs2_quota_lock
-> gfs2_quota_hold is called from gfs2_iomap_begin. At the end of the
write, before unlocking the quotas, punch_hole -> gfs2_quota_hold can be
called again in gfs2_iomap_end, which is incorrect and leads to a failed
assertion. Instead, move the call to gfs2_quota_unlock before the call
to punch_hole to fix that.

Fixes: 64bc06bb32ee ("gfs2: iomap buffered write support")
Cc: stable@xxxxxxxxxxxxxxx # v4.19+
Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/gfs2/bmap.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -1230,6 +1230,9 @@ static int gfs2_iomap_end(struct inode *

gfs2_inplace_release(ip);

+ if (ip->i_qadata && ip->i_qadata->qa_qd_num)
+ gfs2_quota_unlock(ip);
+
if (length != written && (iomap->flags & IOMAP_F_NEW)) {
/* Deallocate blocks that were just allocated. */
loff_t blockmask = i_blocksize(inode) - 1;
@@ -1242,9 +1245,6 @@ static int gfs2_iomap_end(struct inode *
}
}

- if (ip->i_qadata && ip->i_qadata->qa_qd_num)
- gfs2_quota_unlock(ip);
-
if (unlikely(!written))
goto out_unlock;