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>
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Alasdair G Kergon

parent
8cbeb67ad5
commit
5657e8fa45
@@ -156,7 +156,7 @@ static inline void dm_consecutive_chunk_count_inc(struct dm_snap_exception *e)
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*/
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static inline sector_t get_dev_size(struct block_device *bdev)
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{
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return bdev->bd_inode->i_size >> SECTOR_SHIFT;
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return i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
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}
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static inline chunk_t sector_to_chunk(struct dm_exception_store *store,
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