diff options
| author | Mikulas Patocka <mpatocka@redhat.com> | 2009-04-02 19:55:23 +0100 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2009-04-02 19:55:23 +0100 |
| commit | a920f6b3accc77d9dddbc98a7426be23ee479625 (patch) | |
| tree | bff633328b5f1362d99a04f7e513a6a4b2084ad8 /drivers/md | |
| parent | 833bb3046b6cb320e775ea2160ddca87d53260d5 (diff) | |
dm: preserve bi_io_vec when resubmitting bios
Device mapper saves and restores various fields in the bio, but it doesn't save
bi_io_vec. If the device driver modifies this after a partially successful
request, dm-raid1 and dm-multipath may attempt to resubmit a bio that has
bi_size inconsistent with the size of vector.
To make requests resubmittable in dm-raid1 and dm-multipath, we must save
and restore the bio vector as well.
To reduce the memory overhead involved in this, we do not save the pages in a
vector and use a 16-bit field size if the page size is less than 65536.
Cc: stable@kernel.org
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/dm-bio-record.h | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/md/dm-bio-record.h b/drivers/md/dm-bio-record.h index d3ec217847d..3a8cfa2645c 100644 --- a/drivers/md/dm-bio-record.h +++ b/drivers/md/dm-bio-record.h @@ -16,30 +16,56 @@ * functions in this file help the target record and restore the * original bio state. */ + +struct dm_bio_vec_details { +#if PAGE_SIZE < 65536 + __u16 bv_len; + __u16 bv_offset; +#else + unsigned bv_len; + unsigned bv_offset; +#endif +}; + struct dm_bio_details { sector_t bi_sector; struct block_device *bi_bdev; unsigned int bi_size; unsigned short bi_idx; unsigned long bi_flags; + struct dm_bio_vec_details bi_io_vec[BIO_MAX_PAGES]; }; static inline void dm_bio_record(struct dm_bio_details *bd, struct bio *bio) { + unsigned i; + bd->bi_sector = bio->bi_sector; bd->bi_bdev = bio->bi_bdev; bd->bi_size = bio->bi_size; bd->bi_idx = bio->bi_idx; bd->bi_flags = bio->bi_flags; + + for (i = 0; i < bio->bi_vcnt; i++) { + bd->bi_io_vec[i].bv_len = bio->bi_io_vec[i].bv_len; + bd->bi_io_vec[i].bv_offset = bio->bi_io_vec[i].bv_offset; + } } static inline void dm_bio_restore(struct dm_bio_details *bd, struct bio *bio) { + unsigned i; + bio->bi_sector = bd->bi_sector; bio->bi_bdev = bd->bi_bdev; bio->bi_size = bd->bi_size; bio->bi_idx = bd->bi_idx; bio->bi_flags = bd->bi_flags; + + for (i = 0; i < bio->bi_vcnt; i++) { + bio->bi_io_vec[i].bv_len = bd->bi_io_vec[i].bv_len; + bio->bi_io_vec[i].bv_offset = bd->bi_io_vec[i].bv_offset; + } } #endif |