From: Josef Bacik <josef@redhat.com>
Date: Mon, 22 Nov 2010 18:50:32 +0000 (+0000)
Subject: Btrfs: fix typo in fallocate to make it honor actual size
X-Git-Tag: v2.6.37-rc4~6^2~7
X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=55a61d1d06a3dc443d0db8aaa613365dcb83b98a

Btrfs: fix typo in fallocate to make it honor actual size

[ Trivial backport to 2.6.35/2.6.36 ]

There is a typo in __btrfs_prealloc_file_range() where we set the i_size to
actual_len/cur_offset, and then just set it to cur_offset again, and do the same
with btrfs_ordered_update_i_size().  This fixes it back to keeping i_size in a
local variable and then updating i_size properly.  Tested this with

xfs_io -F -f -c "falloc 0 1" -c "pwrite 0 1" foo

stat'ing foo gives us a size of 1 instead of 4096 like it was.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
---

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 37cc177..0058fb3 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7002,6 +7002,7 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 	struct btrfs_key ins;
 	u64 cur_offset = start;
+	u64 i_size;
 	int ret = 0;
 
 	while (num_bytes > 0) {
@@ -7043,11 +7044,11 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
 		    (actual_len > inode->i_size) &&
 		    (cur_offset > inode->i_size)) {
 			if (cur_offset > actual_len)
-				i_size_write(inode, actual_len);
+				i_size = actual_len;
 			else
-				i_size_write(inode, cur_offset);
-			i_size_write(inode, cur_offset);
-			btrfs_ordered_update_i_size(inode, cur_offset, NULL);
+				i_size = cur_offset;
+			i_size_write(inode, i_size);
+			btrfs_ordered_update_i_size(inode, i_size, NULL);
 		}
 
 		ret = btrfs_update_inode(trans, root, inode);