3 files changed, 121 insertions, 54 deletions

diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index 7d287afccde..691f61223ed 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -934,7 +934,6 @@ xfs_aops_discard_page(
         struct xfs_inode        *ip = XFS_I(inode);
         struct buffer_head      *bh, *head;
         loff_t                  offset = page_offset(page);
-        ssize_t                 len = 1 << inode->i_blkbits;
 
         if (!xfs_is_delayed_page(page, IO_DELAY))
                 goto out_invalidate;
@@ -949,58 +948,14 @@ xfs_aops_discard_page(
         xfs_ilock(ip, XFS_ILOCK_EXCL);
         bh = head = page_buffers(page);
         do {
-                int             done;
-                xfs_fileoff_t   offset_fsb;
-                xfs_bmbt_irec_t imap;
-                int             nimaps = 1;
                 int             error;
-                xfs_fsblock_t   firstblock;
-                xfs_bmap_free_t flist;
+                xfs_fileoff_t   start_fsb;
 
                 if (!buffer_delay(bh))
                         goto next_buffer;
 
-                offset_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
-
-                /*
-                 * Map the range first and check that it is a delalloc extent
-                 * before trying to unmap the range. Otherwise we will be
-                 * trying to remove a real extent (which requires a
-                 * transaction) or a hole, which is probably a bad idea...
-                 */
-                error = xfs_bmapi(NULL, ip, offset_fsb, 1,
-                                XFS_BMAPI_ENTIRE,  NULL, 0, &imap,
-                                &nimaps, NULL);
-
-                if (error) {
-                        /* something screwed, just bail */
-                        if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
-                                xfs_fs_cmn_err(CE_ALERT, ip->i_mount,
-                                "page discard failed delalloc mapping lookup.");
-                        }
-                        break;
-                }
-                if (!nimaps) {
-                        /* nothing there */
-                        goto next_buffer;
-                }
-                if (imap.br_startblock != DELAYSTARTBLOCK) {
-                        /* been converted, ignore */
-                        goto next_buffer;
-                }
-                WARN_ON(imap.br_blockcount == 0);
-
-                /*
-                 * Note: while we initialise the firstblock/flist pair, they
-                 * should never be used because blocks should never be
-                 * allocated or freed for a delalloc extent and hence we need
-                 * don't cancel or finish them after the xfs_bunmapi() call.
-                 */
-                xfs_bmap_init(&flist, &firstblock);
-                error = xfs_bunmapi(NULL, ip, offset_fsb, 1, 0, 1, &firstblock,
-                                        &flist, &done);
-
-                ASSERT(!flist.xbf_count && !flist.xbf_first);
+                start_fsb = XFS_B_TO_FSBT(ip->i_mount, offset);
+                error = xfs_bmap_punch_delalloc_range(ip, start_fsb, 1);
                 if (error) {
                         /* something screwed, just bail */
                         if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
@@ -1010,7 +965,7 @@ xfs_aops_discard_page(
                         break;
                 }
 next_buffer:
-                offset += len;
+                offset += 1 << inode->i_blkbits;
 
         } while ((bh = bh->b_this_page) != head);
 
@@ -1505,11 +1460,42 @@ xfs_vm_write_failed(
         struct inode            *inode = mapping->host;
 
         if (to > inode->i_size) {
-                struct iattr    ia = {
-                        .ia_valid       = ATTR_SIZE | ATTR_FORCE,
-                        .ia_size        = inode->i_size,
-                };
-                xfs_setattr(XFS_I(inode), &ia, XFS_ATTR_NOLOCK);
+                /*
+                 * punch out the delalloc blocks we have already allocated. We
+                 * don't call xfs_setattr() to do this as we may be in the
+                 * middle of a multi-iovec write and so the vfs inode->i_size
+                 * will not match the xfs ip->i_size and so it will zero too
+                 * much. Hence we jus truncate the page cache to zero what is
+                 * necessary and punch the delalloc blocks directly.
+                 */
+                struct xfs_inode        *ip = XFS_I(inode);
+                xfs_fileoff_t           start_fsb;
+                xfs_fileoff_t           end_fsb;
+                int                     error;
+
+                truncate_pagecache(inode, to, inode->i_size);
+
+                /*
+                 * Check if there are any blocks that are outside of i_size
+                 * that need to be trimmed back.
+                 */
+                start_fsb = XFS_B_TO_FSB(ip->i_mount, inode->i_size) + 1;
+                end_fsb = XFS_B_TO_FSB(ip->i_mount, to);
+                if (end_fsb <= start_fsb)
+                        return;
+
+                xfs_ilock(ip, XFS_ILOCK_EXCL);
+                error = xfs_bmap_punch_delalloc_range(ip, start_fsb,
+                                                        end_fsb - start_fsb);
+                if (error) {
+                        /* something screwed, just bail */
+                        if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
+                                xfs_fs_cmn_err(CE_ALERT, ip->i_mount,
+                        "xfs_vm_write_failed: unable to clean up ino %lld",
+                                                ip->i_ino);
+                        }
+                }
+                xfs_iunlock(ip, XFS_ILOCK_EXCL);
         }
 }
 
diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 8abd12e32e1..08b179fa9e8 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -6070,3 +6070,79 @@ xfs_bmap_disk_count_leaves(
                 *count += xfs_bmbt_disk_get_blockcount(frp);
         }
 }
+
+/*
+ * dead simple method of punching delalyed allocation blocks from a range in
+ * the inode. Walks a block at a time so will be slow, but is only executed in
+ * rare error cases so the overhead is not critical. This will alays punch out
+ * both the start and end blocks, even if the ranges only partially overlap
+ * them, so it is up to the caller to ensure that partial blocks are not
+ * passed in.
+ */
+int
+xfs_bmap_punch_delalloc_range(
+        struct xfs_inode        *ip,
+        xfs_fileoff_t           start_fsb,
+        xfs_fileoff_t           length)
+{
+        xfs_fileoff_t           remaining = length;
+        int                     error = 0;
+
+        ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+
+        do {
+                int             done;
+                xfs_bmbt_irec_t imap;
+                int             nimaps = 1;
+                xfs_fsblock_t   firstblock;
+                xfs_bmap_free_t flist;
+
+                /*
+                 * Map the range first and check that it is a delalloc extent
+                 * before trying to unmap the range. Otherwise we will be
+                 * trying to remove a real extent (which requires a
+                 * transaction) or a hole, which is probably a bad idea...
+                 */
+                error = xfs_bmapi(NULL, ip, start_fsb, 1,
+                                XFS_BMAPI_ENTIRE,  NULL, 0, &imap,
+                                &nimaps, NULL);
+
+                if (error) {
+                        /* something screwed, just bail */
+                        if (!XFS_FORCED_SHUTDOWN(ip->i_mount)) {
+                                xfs_fs_cmn_err(CE_ALERT, ip->i_mount,
+                        "Failed delalloc mapping lookup ino %lld fsb %lld.",
+                                                ip->i_ino, start_fsb);
+                        }
+                        break;
+                }
+                if (!nimaps) {
+                        /* nothing there */
+                        goto next_block;
+                }
+                if (imap.br_startblock != DELAYSTARTBLOCK) {
+                        /* been converted, ignore */
+                        goto next_block;
+                }
+                WARN_ON(imap.br_blockcount == 0);
+
+                /*
+                 * Note: while we initialise the firstblock/flist pair, they
+                 * should never be used because blocks should never be
+                 * allocated or freed for a delalloc extent and hence we need
+                 * don't cancel or finish them after the xfs_bunmapi() call.
+                 */
+                xfs_bmap_init(&flist, &firstblock);
+                error = xfs_bunmapi(NULL, ip, start_fsb, 1, 0, 1, &firstblock,
+                                        &flist, &done);
+                if (error)
+                        break;
+
+                ASSERT(!flist.xbf_count && !flist.xbf_first);
+next_block:
+                start_fsb++;
+                remaining--;
+        } while(remaining > 0);
+
+        return error;
+}
diff --git a/fs/xfs/xfs_bmap.h b/fs/xfs/xfs_bmap.h
index 71ec9b6ecdf..3651191daea 100644
--- a/fs/xfs/xfs_bmap.h
+++ b/fs/xfs/xfs_bmap.h
@@ -394,6 +394,11 @@ xfs_bmap_count_blocks(
         int                     whichfork,
         int                     *count);
 
+int
+xfs_bmap_punch_delalloc_range(
+        struct xfs_inode        *ip,
+        xfs_fileoff_t           start_fsb,
+        xfs_fileoff_t           length);
 #endif  /* __KERNEL__ */
 
 #endif  /* __XFS_BMAP_H__ */