From aad3f3755e7f043789b772856d1a2935f2b41a4b Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 14 Apr 2014 18:14:11 +1000 Subject: xfs: xfs_vm_write_end truncates too much on failure Similar to the write_begin problem, xfs-vm_write_end will truncate back to the old EOF, potentially removing page cache from over the top of delalloc blocks with valid data in them. Fix this by truncating back to just the start of the failed write. Signed-off-by: Dave Chinner Tested-by: Brian Foster Reviewed-by: Christoph Hellwig Signed-off-by: Dave Chinner --- fs/xfs/xfs_aops.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index 5f296934879f..e0a793113ea9 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -1634,9 +1634,12 @@ xfs_vm_write_begin( } /* - * On failure, we only need to kill delalloc blocks beyond EOF because they - * will never be written. For blocks within EOF, generic_write_end() zeros them - * so they are safe to leave alone and be written with all the other valid data. + * On failure, we only need to kill delalloc blocks beyond EOF in the range of + * this specific write because they will never be written. Previous writes + * beyond EOF where block allocation succeeded do not need to be trashed, so + * only new blocks from this write should be trashed. For blocks within + * EOF, generic_write_end() zeros them so they are safe to leave alone and be + * written with all the other valid data. */ STATIC int xfs_vm_write_end( @@ -1659,8 +1662,11 @@ xfs_vm_write_end( loff_t to = pos + len; if (to > isize) { - truncate_pagecache(inode, isize); + /* only kill blocks in this write beyond EOF */ + if (pos > isize) + isize = pos; xfs_vm_kill_delalloc_range(inode, isize, to); + truncate_pagecache_range(inode, isize, to); } } return ret; -- cgit v1.2.3