From 4df0f7f145f2ac143039e2c569d17a25354f411d Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Tue, 6 Mar 2018 17:07:22 -0800 Subject: xfs: fix transaction allocation deadlock in IO path xfs_trans_alloc() does GFP_KERNEL allocation, and we can call it while holding pages locked for writeback in the ->writepages path. The memory allocation is allowed to wait on pages under writeback, and so can wait on pages that are tagged as writeback by the caller. This affects both pre-IO submission and post-IO submission paths. Hence xfs_setsize_trans_alloc(), xfs_reflink_end_cow(), xfs_iomap_write_unwritten() and xfs_reflink_cancel_cow_range(). xfs_iomap_write_unwritten() already does the right thing, but the others don't. Fix them. Signed-Off-By: Dave Chinner Fixes: 281627df3eb5 ("xfs: log file size updates at I/O completion time") Fixes: 43caeb187deb9 ("xfs: move mappings from cow fork to data fork after copy-write)" Reviewed-by: Eric Sandeen Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_aops.c | 3 ++- fs/xfs/xfs_reflink.c | 4 ++-- 2 files changed, 4 insertions(+), 3 deletions(-) (limited to 'fs/xfs') diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index 9c6a830da0ee..a0afb6411417 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -209,7 +209,8 @@ xfs_setfilesize_trans_alloc( struct xfs_trans *tp; int error; - error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, 0, &tp); + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_fsyncts, 0, 0, + XFS_TRANS_NOFS, &tp); if (error) return error; diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index 270246943a06..8c16177b33d4 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -668,7 +668,7 @@ xfs_reflink_cancel_cow_range( /* Start a rolling transaction to remove the mappings */ error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, - 0, 0, 0, &tp); + 0, 0, XFS_TRANS_NOFS, &tp); if (error) goto out; @@ -741,7 +741,7 @@ xfs_reflink_end_cow( (unsigned int)(end_fsb - offset_fsb), XFS_DATA_FORK); error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_write, - resblks, 0, XFS_TRANS_RESERVE, &tp); + resblks, 0, XFS_TRANS_RESERVE | XFS_TRANS_NOFS, &tp); if (error) goto out; -- cgit v1.2.3