xfs: I/O completion handlers must use NOFS allocations
When completing I/O requests we must not allow the memory allocator to
recurse into the filesystem, as we might deadlock on waiting for the
I/O completion otherwise. The only thing currently allocating normal
GFP_KERNEL memory is the allocation of the transaction structure for
the unwritten extent conversion. Add a memflags argument to
_xfs_trans_alloc to allow controlling the allocator behaviour.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Thomas Neumann <tneumann@users.sourceforge.net>
Tested-by: Thomas Neumann <tneumann@users.sourceforge.net>
Reviewed-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 66b8493..237badc 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -236,19 +236,20 @@
uint type)
{
xfs_wait_for_freeze(mp, SB_FREEZE_TRANS);
- return _xfs_trans_alloc(mp, type);
+ return _xfs_trans_alloc(mp, type, KM_SLEEP);
}
xfs_trans_t *
_xfs_trans_alloc(
xfs_mount_t *mp,
- uint type)
+ uint type,
+ uint memflags)
{
xfs_trans_t *tp;
atomic_inc(&mp->m_active_trans);
- tp = kmem_zone_zalloc(xfs_trans_zone, KM_SLEEP);
+ tp = kmem_zone_zalloc(xfs_trans_zone, memflags);
tp->t_magic = XFS_TRANS_MAGIC;
tp->t_type = type;
tp->t_mountp = mp;