[PATCH 02/14] xfs: fix rounding in xfs_free_file_space

Dave Chinner
2013-05-19T23:51:51Z

From: Dave Chinner <dchinner@redhat.com>

The offset passed into xfs_free_file_space() needs to be rounded
down to a certain size, but the rounding mask is built by a 32 bit
variable. Hence the mask will always mask off the upper 32 bits of
the offset and lead to incorrect writeback and invalidation ranges.

This is not actually exposed as a bug because we writeback and
invalidate from the rounded offset to the end of the file, and hence
the offset we are actually punching a hole out of will always be
covered by the code. This needs fixing, however, if we ever want to
use exact ranges for writeback/invalidation here...

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_vnodeops.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 1501f4f..0176bb2 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -1453,7 +1453,7 @@ xfs_free_file_space(
xfs_mount_t *mp;
int nimap;
uint resblks;
- uint rounding;
+ xfs_off_t rounding;
int rt;
xfs_fileoff_t startoffset_fsb;
xfs_trans_t *tp;
@@ -1482,7 +1482,7 @@ xfs_free_file_space(
inode_dio_wait(VFS_I(ip));
}

- rounding = max_t(uint, 1 << mp->m_sb.sb_blocklog, PAGE_CACHE_SIZE);
+ rounding = max_t(xfs_off_t, 1 << mp->m_sb.sb_blocklog, PAGE_CACHE_SIZE);
ioffset = offset & ~(rounding - 1);
error = -filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
ioffset, -1);
--
1.7.10.4