Commit 80641dc6 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Alex Elder
Browse files

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: default avatarChristoph Hellwig <hch@lst.de>
Reported-by: default avatarThomas Neumann <tneumann@users.sourceforge.net>
Tested-by: default avatarThomas Neumann <tneumann@users.sourceforge.net>
Reviewed-by: default avatarAlex Elder <aelder@sgi.com>
Signed-off-by: default avatarAlex Elder <aelder@sgi.com>
parent c56c9631

fs/xfs/xfs_fsops.c

+1 −1
Original line number Diff line number Diff line
@@ -611,7 +611,7 @@ xfs_fs_log_dummy( 
	xfs_inode_t	*ip;

	int		error;



	tp = _xfs_trans_alloc(mp, XFS_TRANS_DUMMY1);

	tp = _xfs_trans_alloc(mp, XFS_TRANS_DUMMY1, KM_SLEEP);

	error = xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES(mp), 0, 0, 0);

	if (error) {

		xfs_trans_cancel(tp, 0);

fs/xfs/xfs_iomap.c

+8 −1
Original line number Diff line number Diff line
@@ -860,8 +860,15 @@ xfs_iomap_write_unwritten( 
		 * set up a transaction to convert the range of extents

		 * from unwritten to real. Do allocations in a loop until

		 * we have covered the range passed in.

		 *

		 * Note that we open code the transaction allocation here

		 * to pass KM_NOFS--we can't risk to recursing back into

		 * the filesystem here as we might be asked to write out

		 * the same inode that we complete here and might deadlock

		 * on the iolock.

		 */

		tp = xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE);

		xfs_wait_for_freeze(mp, SB_FREEZE_TRANS);

		tp = _xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE, KM_NOFS);

		tp->t_flags |= XFS_TRANS_RESERVE;

		error = xfs_trans_reserve(tp, resblks,

				XFS_WRITE_LOG_RES(mp), 0,

fs/xfs/xfs_mount.c

+1 −1
Original line number Diff line number Diff line
@@ -1471,7 +1471,7 @@ xfs_log_sbcount( 
	if (!xfs_sb_version_haslazysbcount(&mp->m_sb))

		return 0;



	tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT);

	tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT, KM_SLEEP);

	error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0,

					XFS_DEFAULT_LOG_COUNT);

	if (error) {

fs/xfs/xfs_trans.c

+4 −3
Original line number Diff line number Diff line
@@ -236,19 +236,20 @@ xfs_trans_alloc( 
	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;

fs/xfs/xfs_trans.h

+1 −1
Original line number Diff line number Diff line
@@ -924,7 +924,7 @@ typedef struct xfs_trans { 
 * XFS transaction mechanism exported interfaces.

 */

xfs_trans_t	*xfs_trans_alloc(struct xfs_mount *, uint);

xfs_trans_t	*_xfs_trans_alloc(struct xfs_mount *, uint);

xfs_trans_t	*_xfs_trans_alloc(struct xfs_mount *, uint, uint);

xfs_trans_t	*xfs_trans_dup(xfs_trans_t *);

int		xfs_trans_reserve(xfs_trans_t *, uint, uint, uint,

				  uint, uint);

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