From: Brian Foster Date: Wed, 1 Oct 2014 23:44:54 +0000 (+1000) Subject: xfs: flush the range before zero range conversion X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=da5f10969d54006a24777a84ed3eaeeb2a21047f;p=linux-beck.git xfs: flush the range before zero range conversion XFS currently discards delalloc blocks within the target range of a zero range request. Unaligned start and end offsets are zeroed through the page cache and the internal, aligned blocks are converted to unwritten extents. If EOF is page aligned and covered by a delayed allocation extent. The inode size is not updated until I/O completion. If a zero range request discards a delalloc range that covers page aligned EOF as such, the inode size update never occurs. For example: $ rm -f /mnt/file $ xfs_io -fc "pwrite 0 64k" -c "zero 60k 4k" /mnt/file $ stat -c "%s" /mnt/file 65536 $ umount /mnt $ mount /mnt $ stat -c "%s" /mnt/file 61440 Update xfs_zero_file_space() to flush the range rather than discard delalloc blocks to ensure that inode size updates occur appropriately. [dchinner: Note that this is really a workaround to avoid the underlying problems. More work is needed (and ongoing) to fix those issues so this fix is being added as a temporary stop-gap measure. ] Signed-off-by: Brian Foster Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index 1cb345e7c181..6f5cb63bed17 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -1392,14 +1392,14 @@ xfs_zero_file_space( if (start_boundary < end_boundary - 1) { /* - * punch out delayed allocation blocks and the page cache over - * the conversion range + * Writeback the range to ensure any inode size updates due to + * appending writes make it to disk (otherwise we could just + * punch out the delalloc blocks). */ - xfs_ilock(ip, XFS_ILOCK_EXCL); - error = xfs_bmap_punch_delalloc_range(ip, - XFS_B_TO_FSBT(mp, start_boundary), - XFS_B_TO_FSB(mp, end_boundary - start_boundary)); - xfs_iunlock(ip, XFS_ILOCK_EXCL); + error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping, + start_boundary, end_boundary - 1); + if (error) + goto out; truncate_pagecache_range(VFS_I(ip), start_boundary, end_boundary - 1);