diff options
| author | Christoph Hellwig <hch@lst.de> | 2023-08-05 08:55:37 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-08-06 01:13:15 +0300 |
| commit | 95848dcb9d676738411a8ff70a9704039f1b3982 (patch) | |
| tree | 685aae478a33f338677ec4e06c073173d1273c4b /drivers/block | |
| parent | a592ab6171bd943ce3b988bd271c79fe275a7bec (diff) | |
| download | linux-95848dcb9d676738411a8ff70a9704039f1b3982.tar.xz | |
zram: take device and not only bvec offset into account
Commit af8b04c63708 ("zram: simplify bvec iteration in
__zram_make_request") changed the bio iteration in zram to rely on the
implicit capping to page boundaries in bio_for_each_segment. But it
failed to care for the fact zram not only care about the page alignment
of the bio payload, but also the page alignment into the device. For
buffered I/O and swap those are the same, but for direct I/O or kernel
internal I/O like XFS log buffer writes they can differ.
Fix this by open coding bio_for_each_segment and limiting the bvec len
so that it never crosses over a page alignment boundary in the device
in addition to the payload boundary already taken care of by
bio_iter_iovec.
Cc: stable@vger.kernel.org
Fixes: af8b04c63708 ("zram: simplify bvec iteration in __zram_make_request")
Reported-by: Dusty Mabe <dusty@dustymabe.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Link: https://lore.kernel.org/r/20230805055537.147835-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/zram/zram_drv.c | 32 |
1 files changed, 20 insertions, 12 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 5676e6dd5b16..06673c6ca255 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1870,15 +1870,16 @@ static void zram_bio_discard(struct zram *zram, struct bio *bio) static void zram_bio_read(struct zram *zram, struct bio *bio) { - struct bvec_iter iter; - struct bio_vec bv; - unsigned long start_time; + unsigned long start_time = bio_start_io_acct(bio); + struct bvec_iter iter = bio->bi_iter; - start_time = bio_start_io_acct(bio); - bio_for_each_segment(bv, bio, iter) { + do { u32 index = iter.bi_sector >> SECTORS_PER_PAGE_SHIFT; u32 offset = (iter.bi_sector & (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT; + struct bio_vec bv = bio_iter_iovec(bio, iter); + + bv.bv_len = min_t(u32, bv.bv_len, PAGE_SIZE - offset); if (zram_bvec_read(zram, &bv, index, offset, bio) < 0) { atomic64_inc(&zram->stats.failed_reads); @@ -1890,22 +1891,26 @@ static void zram_bio_read(struct zram *zram, struct bio *bio) zram_slot_lock(zram, index); zram_accessed(zram, index); zram_slot_unlock(zram, index); - } + + bio_advance_iter_single(bio, &iter, bv.bv_len); + } while (iter.bi_size); + bio_end_io_acct(bio, start_time); bio_endio(bio); } static void zram_bio_write(struct zram *zram, struct bio *bio) { - struct bvec_iter iter; - struct bio_vec bv; - unsigned long start_time; + unsigned long start_time = bio_start_io_acct(bio); + struct bvec_iter iter = bio->bi_iter; - start_time = bio_start_io_acct(bio); - bio_for_each_segment(bv, bio, iter) { + do { u32 index = iter.bi_sector >> SECTORS_PER_PAGE_SHIFT; u32 offset = (iter.bi_sector & (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT; + struct bio_vec bv = bio_iter_iovec(bio, iter); + + bv.bv_len = min_t(u32, bv.bv_len, PAGE_SIZE - offset); if (zram_bvec_write(zram, &bv, index, offset, bio) < 0) { atomic64_inc(&zram->stats.failed_writes); @@ -1916,7 +1921,10 @@ static void zram_bio_write(struct zram *zram, struct bio *bio) zram_slot_lock(zram, index); zram_accessed(zram, index); zram_slot_unlock(zram, index); - } + + bio_advance_iter_single(bio, &iter, bv.bv_len); + } while (iter.bi_size); + bio_end_io_acct(bio, start_time); bio_endio(bio); } |