Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758704Ab0DVUr5 (ORCPT ); Thu, 22 Apr 2010 16:47:57 -0400 Received: from kroah.org ([198.145.64.141]:37156 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755745Ab0DVT1e (ORCPT ); Thu, 22 Apr 2010 15:27:34 -0400 X-Mailbox-Line: From gregkh@kvm.kroah.org Thu Apr 22 12:09:08 2010 Message-Id: <20100422190908.397864177@kvm.kroah.org> User-Agent: quilt/0.48-4.4 Date: Thu, 22 Apr 2010 12:07:42 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, xfs@oss.sgi.com, Christoph Hellwig , Alex Elder Subject: [011/197] xfs: I/O completion handlers must use NOFS allocations In-Reply-To: <20100422191857.GA13268@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3925 Lines: 115 2.6.32-stable review patch. If anyone has any objections, please let us know. ------------------ From: Christoph Hellwig commit 80641dc66a2d6dfb22af4413227a92b8ab84c7bb upstream 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 Reported-by: Thomas Neumann Tested-by: Thomas Neumann Reviewed-by: Alex Elder Signed-off-by: Alex Elder Signed-off-by: Greg Kroah-Hartman --- fs/xfs/xfs_fsops.c | 2 +- fs/xfs/xfs_iomap.c | 9 ++++++++- fs/xfs/xfs_mount.c | 2 +- fs/xfs/xfs_trans.c | 7 ++++--- fs/xfs/xfs_trans.h | 2 +- 5 files changed, 15 insertions(+), 7 deletions(-) --- a/fs/xfs/xfs_fsops.c +++ b/fs/xfs/xfs_fsops.c @@ -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); --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -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, --- a/fs/xfs/xfs_mount.c +++ b/fs/xfs/xfs_mount.c @@ -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) { --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -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; --- a/fs/xfs/xfs_trans.h +++ b/fs/xfs/xfs_trans.h @@ -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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/