On Tue, May 22, 2007 at 04:05:59PM +1000, David Chinner wrote:
> On Tue, May 22, 2007 at 02:10:14PM +1000, Nathan Scott wrote:
> > On Tue, 2007-05-22 at 11:03 +1000, David Chinner wrote:
> > > On Tue, May 22, 2007 at 11:02:59AM +1000, Nathan Scott wrote:
> > > > On Tue, 2007-05-22 at 10:44 +1000, David Chinner wrote:
> > > > > On Mon, May 21, 2007 at 04:34:26PM +1000, Timothy Shimmin wrote:
> > > > > I guess I need to ping Christoph and Nathan on this one....
> > > >
> > > > Could you resend the patch to me please? I lost the previous copy
> > > > while ruthlessly ploughing through my mail backlog. ;)
> > >
> > > Below.
> >
> > Looks pretty good to me - xfs_convert_page has been overlooked, I
> > think - attached patch fixes that.
....
> I'll make the change anyway to be safe, but I'm still perplexed
> as to why it doesn't seem necessary....
>
> Ah - there it is - xfs_is_delayed_page():
>
> 699 if (buffer_unwritten(bh))
> 700 acceptable = (type ==
> IOMAP_UNWRITTEN);
> 701 else if (buffer_delay(bh))
> 702 acceptable = (type == IOMAP_DELAY);
> 703 else if (buffer_dirty(bh) &&
> buffer_mapped(bh))
> 704 >>>>>>>>>>> acceptable = (type == 0);
> 705 else
> 706 break;
>
> The ioend we started with now has type = IOMAP_NEW = 0x40 which
> means xfs_convert_page() aborts clustering this case immediately.
> IOWs, we are never getting to this xfs_convert_page() case and
> we are only passing through xfs_page_state_convert for mapped
> pages.
>
> > You also initialise iomap_valid
> > twice inside xfs_page_state_convert now ... I reverted that to just
> > the once.
>
> I'll fold these changes in and fixup xfs_is_delayed_page() to look
> for type == IOMAP_NEW and send out a new patch. Thanks, Nathan.
Patch below, Nathan. It's passed my point tests and XFSQA...
Cheers,
Dave.
--
Dave Chinner
Principal Engineer
SGI Australian Software Group
---
fs/xfs/linux-2.6/xfs_aops.c | 26 +++++++++++++++++---------
1 file changed, 17 insertions(+), 9 deletions(-)
Index: 2.6.x-xfs-new/fs/xfs/linux-2.6/xfs_aops.c
===================================================================
--- 2.6.x-xfs-new.orig/fs/xfs/linux-2.6/xfs_aops.c 2007-05-21
17:49:01.603432320 +1000
+++ 2.6.x-xfs-new/fs/xfs/linux-2.6/xfs_aops.c 2007-05-22 16:07:36.787017461
+1000
@@ -706,7 +706,7 @@ xfs_is_delayed_page(
else if (buffer_delay(bh))
acceptable = (type == IOMAP_DELAY);
else if (buffer_dirty(bh) && buffer_mapped(bh))
- acceptable = (type == 0);
+ acceptable = (type == IOMAP_NEW);
else
break;
} while ((bh = bh->b_this_page) != head);
@@ -815,7 +815,7 @@ xfs_convert_page(
page_dirty--;
count++;
} else {
- type = 0;
+ type = IOMAP_NEW;
if (buffer_mapped(bh) && all_bh && startio) {
lock_buffer(bh);
xfs_add_to_ioend(inode, bh, offset,
@@ -973,8 +973,8 @@ xfs_page_state_convert(
bh = head = page_buffers(page);
offset = page_offset(page);
- flags = -1;
- type = IOMAP_READ;
+ flags = BMAPI_READ;
+ type = IOMAP_NEW;
/* TODO: cleanup count and page_dirty */
@@ -1004,14 +1004,14 @@ xfs_page_state_convert(
*
* Third case, an unmapped buffer was found, and we are
* in a path where we need to write the whole page out.
- */
+ */
if (buffer_unwritten(bh) || buffer_delay(bh) ||
((buffer_uptodate(bh) || PageUptodate(page)) &&
!buffer_mapped(bh) && (unmapped || startio))) {
- /*
+ /*
* Make sure we don't use a read-only iomap
*/
- if (flags == BMAPI_READ)
+ if (flags == BMAPI_READ)
iomap_valid = 0;
if (buffer_unwritten(bh)) {
@@ -1060,7 +1060,7 @@ xfs_page_state_convert(
* That means it must already have extents allocated
* underneath it. Map the extent by reading it.
*/
- if (!iomap_valid || type != IOMAP_READ) {
+ if (!iomap_valid || flags != BMAPI_READ) {
flags = BMAPI_READ;
size = xfs_probe_cluster(inode, page, bh,
head, 1);
@@ -1071,7 +1071,15 @@ xfs_page_state_convert(
iomap_valid = xfs_iomap_valid(&iomap, offset);
}
- type = IOMAP_READ;
+ /*
+ * We set the type to IOMAP_NEW in case we are doing a
+ * small write at EOF that is extending the file but
+ * without needing an allocation. We need to update the
+ * file size on I/O completion in this case so it is
+ * the same case as having just allocated a new extent
+ * that we are writing into for the first time.
+ */
+ type = IOMAP_NEW;
if (!test_and_set_bit(BH_Lock, &bh->b_state)) {
ASSERT(buffer_mapped(bh));
if (iomap_valid)
|