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Commit 85da94c6 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Alex Elder
Browse files

xfs: improve mapping type check in xfs_vm_writepage 



Currently we only refuse a "read-only" mapping for writing out
unwritten and delayed buffers, and refuse any other for overwrites.
Improve the checks to require delalloc mappings for delayed buffers,
and unwritten extent mappings for unwritten extents.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
Signed-off-by: default avatarAlex Elder <aelder@sgi.com>
parent c9f71f5f

fs/xfs/linux-2.6/xfs_aops.c

+12 −9
Original line number Diff line number Diff line
@@ -1082,17 +1082,17 @@ xfs_vm_writepage( 
		if (buffer_unwritten(bh) || buffer_delay(bh)) {

			int new_ioend = 0;



			/*

			 * Make sure we don't use a read-only iomap

			 */

			if (flags == BMAPI_READ)

				imap_valid = 0;



			if (buffer_unwritten(bh)) {

				if (type != IO_UNWRITTEN) {

					type = IO_UNWRITTEN;

					imap_valid = 0;

				}

				flags = BMAPI_WRITE | BMAPI_IGNSTATE;

			} else if (buffer_delay(bh)) {

				if (type != IO_DELAY) {

					type = IO_DELAY;

					imap_valid = 0;

				}

				flags = BMAPI_ALLOCATE;



				if (wbc->sync_mode == WB_SYNC_NONE)
@@ -1128,8 +1128,11 @@ xfs_vm_writepage( 
			 * That means it must already have extents allocated

			 * underneath it. Map the extent by reading it.

			 */

			if (!imap_valid || flags != BMAPI_READ) {

			if (flags != BMAPI_READ) {

				flags = BMAPI_READ;

				imap_valid = 0;

			}

			if (!imap_valid) {

				size = xfs_probe_cluster(inode, page, bh, head);

				err = xfs_map_blocks(inode, offset, size,

						&imap, flags);