[dm-devel] [PATCH] use i_size_read() instead of i_size
Mikulas Patocka
mpatocka at redhat.com
Mon May 18 15:35:51 UTC 2009
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).
Signed-off-by: Mikulas Patocka <mpatocka at redhat.com>
---
drivers/md/dm-exception-store.h | 2 +-
drivers/md/dm-log.c | 2 +-
drivers/md/dm-table.c | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)
Index: linux-2.6.30-rc5-fast/drivers/md/dm-exception-store.h
===================================================================
--- linux-2.6.30-rc5-fast.orig/drivers/md/dm-exception-store.h 2009-05-18 17:29:01.000000000 +0200
+++ linux-2.6.30-rc5-fast/drivers/md/dm-exception-store.h 2009-05-18 17:29:24.000000000 +0200
@@ -156,7 +156,7 @@ static inline void dm_consecutive_chunk_
*/
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,
Index: linux-2.6.30-rc5-fast/drivers/md/dm-log.c
===================================================================
--- linux-2.6.30-rc5-fast.orig/drivers/md/dm-log.c 2009-05-18 17:29:32.000000000 +0200
+++ linux-2.6.30-rc5-fast/drivers/md/dm-log.c 2009-05-18 17:29:42.000000000 +0200
@@ -431,7 +431,7 @@ static int create_log_context(struct dm_
buf_size = dm_round_up((LOG_OFFSET << SECTOR_SHIFT) +
bitset_size, ti->limits.hardsect_size);
- if (buf_size > dev->bdev->bd_inode->i_size) {
+ if (buf_size > i_size_read(dev->bdev->bd_inode)) {
DMWARN("log device %s too small: need %llu bytes",
dev->name, (unsigned long long)buf_size);
kfree(lc);
Index: linux-2.6.30-rc5-fast/drivers/md/dm-table.c
===================================================================
--- linux-2.6.30-rc5-fast.orig/drivers/md/dm-table.c 2009-05-18 17:29:46.000000000 +0200
+++ linux-2.6.30-rc5-fast/drivers/md/dm-table.c 2009-05-18 17:29:57.000000000 +0200
@@ -387,7 +387,7 @@ static void close_dev(struct dm_dev_inte
static int device_area_is_valid(struct dm_target *ti, struct block_device *bdev,
sector_t start, sector_t len)
{
- sector_t dev_size = bdev->bd_inode->i_size >> SECTOR_SHIFT;
+ sector_t dev_size = i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
unsigned short hardsect_size_sectors = ti->limits.hardsect_size >>
SECTOR_SHIFT;
char b[BDEVNAME_SIZE];
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