dm: use i_size_read

Use i_size_read() instead of reading i_size.

If someone changes the size of the device simultaneously, i_size_read
is guaranteed to return a valid value (either the old one or the new one).

i_size can return some intermediate invalid value (on 32-bit computers
with 64-bit i_size, the reads to both halves of i_size can be interleaved
with updates to i_size, resulting in garbage being returned).

Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Mikulas Patocka
2009-06-22 10:12:14 +01:00
committed by Alasdair G Kergon
parent 8cbeb67ad5
commit 5657e8fa45
3 changed files with 4 additions and 3 deletions

View File

@@ -156,7 +156,7 @@ static inline void dm_consecutive_chunk_count_inc(struct dm_snap_exception *e)
*/
static inline sector_t get_dev_size(struct block_device *bdev)
{
return bdev->bd_inode->i_size >> SECTOR_SHIFT;
return i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
}
static inline chunk_t sector_to_chunk(struct dm_exception_store *store,