xfs
[Top] [All Lists]

Re: Review: ensure EOF writes into existing extents update filesize

To: Nathan Scott <nscott@xxxxxxxxxx>
Subject: Re: Review: ensure EOF writes into existing extents update filesize
From: David Chinner <dgc@xxxxxxx>
Date: Tue, 22 May 2007 11:03:26 +1000
Cc: David Chinner <dgc@xxxxxxx>, Timothy Shimmin <tes@xxxxxxx>, xfs-dev <xfs-dev@xxxxxxx>, xfs-oss <xfs@xxxxxxxxxxx>
In-reply-to: <1179795779.6273.510.camel@edge>
References: <20070520233417.GA85884050@sgi.com> <738172E9F9634F7FC01B5B3C@timothy-shimmins-power-mac-g5.local> <20070522004414.GL85884050@sgi.com> <1179795779.6273.510.camel@edge>
Sender: xfs-bounce@xxxxxxxxxxx
User-agent: Mutt/1.4.2.1i
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.

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group

---
 fs/xfs/linux-2.6/xfs_aops.c |   23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 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      2007-05-11 
16:03:59.000000000 +1000
+++ 2.6.x-xfs-new/fs/xfs/linux-2.6/xfs_aops.c   2007-05-12 23:46:54.379994052 
+1000
@@ -973,8 +973,9 @@ xfs_page_state_convert(
 
        bh = head = page_buffers(page);
        offset = page_offset(page);
-       flags = -1;
-       type = IOMAP_READ;
+       iomap_valid = 0;
+       flags = BMAPI_READ;
+       type = IOMAP_NEW;
 
        /* TODO: cleanup count and page_dirty */
 
@@ -1004,14 +1005,14 @@ 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 +1061,7 @@ 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 +1072,15 @@ 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)


<Prev in Thread] Current Thread [Next in Thread>