[XFS] Map unwritten extents correctly for I/o completion processing
If we have multiple unwritten extents within a single page, we fail to
tell the I/o completion construction handlers we need a new handle for the
second and subsequent blocks in the page. While we still issue the I/O
correctly, we do not have the correct ranges recorded in the ioend
structures and hence when we go to convert the unwritten extents we screw
it up.
Make sure we start a new ioend every time the mapping changes so that we
convert the correct ranges on I/O completion.
SGI-PV: 964647
SGI-Modid: xfs-linux-melb:xfs-kern:28797a
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index c097e4e..fd4105d 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -1010,6 +1010,8 @@
if (buffer_unwritten(bh) || buffer_delay(bh) ||
((buffer_uptodate(bh) || PageUptodate(page)) &&
!buffer_mapped(bh) && (unmapped || startio))) {
+ int new_ioend = 0;
+
/*
* Make sure we don't use a read-only iomap
*/
@@ -1028,6 +1030,15 @@
}
if (!iomap_valid) {
+ /*
+ * if we didn't have a valid mapping then we
+ * need to ensure that we put the new mapping
+ * in a new ioend structure. This needs to be
+ * done to ensure that the ioends correctly
+ * reflect the block mappings at io completion
+ * for unwritten extent conversion.
+ */
+ new_ioend = 1;
if (type == IOMAP_NEW) {
size = xfs_probe_cluster(inode,
page, bh, head, 0);
@@ -1047,7 +1058,7 @@
if (startio) {
xfs_add_to_ioend(inode, bh, offset,
type, &ioend,
- !iomap_valid);
+ new_ioend);
} else {
set_buffer_dirty(bh);
unlock_buffer(bh);