2.6.35-longterm review patch.  If anyone has any objections, please let me know.

------------------
From: Yongqiang Yang <[email protected]>

commit 5b41395fcc0265fc9f193aef9df39ce49d64677c upstream.

When writing a contiguous set of blocks, two indirect blocks could be
needed depending on how the blocks are aligned, so we need to increase
the number of credits needed by one.

[ Also fixed a another bug which could further underestimate the
  number of journal credits needed by 1; the code was using integer
  division instead of DIV_ROUND_UP() -- tytso]

Signed-off-by: Yongqiang Yang <[email protected]>
Signed-off-by: "Theodore Ts'o" <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Andi Kleen <[email protected]>

---
 fs/ext4/inode.c |   11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

Index: linux-2.6.35.y/fs/ext4/inode.c
===================================================================
--- linux-2.6.35.y.orig/fs/ext4/inode.c
+++ linux-2.6.35.y/fs/ext4/inode.c
@@ -5593,13 +5593,12 @@ static int ext4_indirect_trans_blocks(st
        /* if nrblocks are contiguous */
        if (chunk) {
                /*
-                * With N contiguous data blocks, it need at most
-                * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
-                * 2 dindirect blocks
-                * 1 tindirect block
+                * With N contiguous data blocks, we need at most
+                * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,
+                * 2 dindirect blocks, and 1 tindirect block
                 */
-               indirects = nrblocks / EXT4_ADDR_PER_BLOCK(inode->i_sb);
-               return indirects + 3;
+               return DIV_ROUND_UP(nrblocks,
+                                   EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4;
        }
        /*
         * if nrblocks are not contiguous, worse case, each block touch

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