From da8b4fc1f63a01a0eca9338ae338b804c437b51f Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Mon, 26 Jun 2023 16:46:00 +0200 Subject: dm integrity: only allocate recalculate buffer when needed dm-integrity preallocated 8MiB buffer for recalculating in the constructor and freed it in the destructor. This wastes memory when the user has many dm-integrity devices. Fix dm-integrity so that the buffer is only allocated when recalculation is in progress; allocate the buffer at the beginning of integrity_recalc() and free it at the end. Note that integrity_recalc() doesn't hold any locks when allocating the buffer, so it shouldn't cause low-memory deadlock. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- drivers/md/dm-integrity.c | 52 +++++++++++++++++++++++------------------------ 1 file changed, 26 insertions(+), 26 deletions(-) (limited to 'drivers/md/dm-integrity.c') diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index 0a910bb8db17..16d1aa263066 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -251,8 +251,6 @@ struct dm_integrity_c { struct workqueue_struct *recalc_wq; struct work_struct recalc_work; - u8 *recalc_buffer; - u8 *recalc_tags; struct bio_list flush_bio_list; @@ -2646,6 +2644,9 @@ static void recalc_write_super(struct dm_integrity_c *ic) static void integrity_recalc(struct work_struct *w) { struct dm_integrity_c *ic = container_of(w, struct dm_integrity_c, recalc_work); + size_t recalc_tags_size; + u8 *recalc_buffer = NULL; + u8 *recalc_tags = NULL; struct dm_integrity_range range; struct dm_io_request io_req; struct dm_io_region io_loc; @@ -2658,6 +2659,20 @@ static void integrity_recalc(struct work_struct *w) int r; unsigned int super_counter = 0; + recalc_buffer = __vmalloc(RECALC_SECTORS << SECTOR_SHIFT, GFP_NOIO); + if (!recalc_buffer) { + DMCRIT("out of memory for recalculate buffer - recalculation disabled"); + goto free_ret; + } + recalc_tags_size = (RECALC_SECTORS >> ic->sb->log2_sectors_per_block) * ic->tag_size; + if (crypto_shash_digestsize(ic->internal_hash) > ic->tag_size) + recalc_tags_size += crypto_shash_digestsize(ic->internal_hash) - ic->tag_size; + recalc_tags = kvmalloc(recalc_tags_size, GFP_NOIO); + if (!recalc_tags) { + DMCRIT("out of memory for recalculate buffer - recalculation disabled"); + goto free_ret; + } + DEBUG_print("start recalculation... (position %llx)\n", le64_to_cpu(ic->sb->recalc_sector)); spin_lock_irq(&ic->endio_wait.lock); @@ -2720,7 +2735,7 @@ next_chunk: io_req.bi_opf = REQ_OP_READ; io_req.mem.type = DM_IO_VMA; - io_req.mem.ptr.addr = ic->recalc_buffer; + io_req.mem.ptr.addr = recalc_buffer; io_req.notify.fn = NULL; io_req.client = ic->io; io_loc.bdev = ic->dev->bdev; @@ -2733,15 +2748,15 @@ next_chunk: goto err; } - t = ic->recalc_tags; + t = recalc_tags; for (i = 0; i < n_sectors; i += ic->sectors_per_block) { - integrity_sector_checksum(ic, logical_sector + i, ic->recalc_buffer + (i << SECTOR_SHIFT), t); + integrity_sector_checksum(ic, logical_sector + i, recalc_buffer + (i << SECTOR_SHIFT), t); t += ic->tag_size; } metadata_block = get_metadata_sector_and_offset(ic, area, offset, &metadata_offset); - r = dm_integrity_rw_tag(ic, ic->recalc_tags, &metadata_block, &metadata_offset, t - ic->recalc_tags, TAG_WRITE); + r = dm_integrity_rw_tag(ic, recalc_tags, &metadata_block, &metadata_offset, t - recalc_tags, TAG_WRITE); if (unlikely(r)) { dm_integrity_io_error(ic, "writing tags", r); goto err; @@ -2769,12 +2784,16 @@ advance_and_next: err: remove_range(ic, &range); - return; + goto free_ret; unlock_ret: spin_unlock_irq(&ic->endio_wait.lock); recalc_write_super(ic); + +free_ret: + vfree(recalc_buffer); + kvfree(recalc_tags); } static void bitmap_block_work(struct work_struct *w) @@ -4439,8 +4458,6 @@ try_smaller_buffer: } if (ic->internal_hash) { - size_t recalc_tags_size; - ic->recalc_wq = alloc_workqueue("dm-integrity-recalc", WQ_MEM_RECLAIM, 1); if (!ic->recalc_wq) { ti->error = "Cannot allocate workqueue"; @@ -4448,21 +4465,6 @@ try_smaller_buffer: goto bad; } INIT_WORK(&ic->recalc_work, integrity_recalc); - ic->recalc_buffer = vmalloc(RECALC_SECTORS << SECTOR_SHIFT); - if (!ic->recalc_buffer) { - ti->error = "Cannot allocate buffer for recalculating"; - r = -ENOMEM; - goto bad; - } - recalc_tags_size = (RECALC_SECTORS >> ic->sb->log2_sectors_per_block) * ic->tag_size; - if (crypto_shash_digestsize(ic->internal_hash) > ic->tag_size) - recalc_tags_size += crypto_shash_digestsize(ic->internal_hash) - ic->tag_size; - ic->recalc_tags = kvmalloc(recalc_tags_size, GFP_KERNEL); - if (!ic->recalc_tags) { - ti->error = "Cannot allocate tags for recalculating"; - r = -ENOMEM; - goto bad; - } } else { if (ic->sb->flags & cpu_to_le32(SB_FLAG_RECALCULATING)) { ti->error = "Recalculate can only be specified with internal_hash"; @@ -4606,8 +4608,6 @@ static void dm_integrity_dtr(struct dm_target *ti) destroy_workqueue(ic->writer_wq); if (ic->recalc_wq) destroy_workqueue(ic->recalc_wq); - vfree(ic->recalc_buffer); - kvfree(ic->recalc_tags); kvfree(ic->bbs); if (ic->bufio) dm_bufio_client_destroy(ic->bufio); -- cgit