Commit 05b30949 authored Oct 17, 2019 by Christoph Hellwig Committed by Darrick J. Wong Oct 21, 2019

xfs: set IOMAP_F_NEW more carefully



Don't set IOMAP_F_NEW if we COW over an existing allocated range, as
these aren't strictly new allocations.  This is required to be able to
use IOMAP_F_NEW to zero newly allocated blocks, which is required for
the iomap code to fully support file systems that don't do delayed
allocations or use unwritten extents.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

parent 2492a606

fs/xfs/xfs_iomap.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -707,9 +707,12 @@ retry:
		* Flag newly allocated delalloc blocks with IOMAP_F_NEW so we punch
		* them out if the write happens to fail.
		*/
		if (whichfork == XFS_DATA_FORK) {
		iomap_flags \|= IOMAP_F_NEW;
		trace_xfs_iomap_alloc(ip, offset, count, whichfork,
		whichfork == XFS_DATA_FORK ? &imap : &cmap);
		trace_xfs_iomap_alloc(ip, offset, count, whichfork, &imap);
		} else {
		trace_xfs_iomap_alloc(ip, offset, count, whichfork, &cmap);
		}
		done:
		if (whichfork == XFS_COW_FORK) {
		if (imap.br_startoff > offset_fsb) {

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