From 9dd59727dbc21d33a9add4c5b308a5775cd5a6ef Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Wed, 19 Jul 2017 11:23:40 -0400 Subject: dm integrity: fix inefficient allocation of journal space When using a block size greater than 512 bytes, the dm-integrity target allocates journal space inefficiently. It allocates one journal entry for each 512-byte chunk of data, fills an entry for each block of data and leaves the remaining entries unused. This issue doesn't cause data corruption, but all the unused journal entries degrade performance severely. For example, with 4k blocks and an 8k bio, it would allocate 16 journal entries but only use 2 entries. The remaining 14 entries were left unused. Fix this by adding the missing 'log2_sectors_per_block' shifts that are required to have each journal entry map to a full block. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Fixes: 7eada909bfd7 ("dm: add integrity target") Signed-off-by: Mike Snitzer --- drivers/md/dm-integrity.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index 1b224aa9cf15..4b2fd524e38d 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -1587,16 +1587,18 @@ retry: if (likely(ic->mode == 'J')) { if (dio->write) { unsigned next_entry, i, pos; - unsigned ws, we; + unsigned ws, we, range_sectors; - dio->range.n_sectors = min(dio->range.n_sectors, ic->free_sectors); + dio->range.n_sectors = min(dio->range.n_sectors, + ic->free_sectors << ic->sb->log2_sectors_per_block); if (unlikely(!dio->range.n_sectors)) goto sleep; - ic->free_sectors -= dio->range.n_sectors; + range_sectors = dio->range.n_sectors >> ic->sb->log2_sectors_per_block; + ic->free_sectors -= range_sectors; journal_section = ic->free_section; journal_entry = ic->free_section_entry; - next_entry = ic->free_section_entry + dio->range.n_sectors; + next_entry = ic->free_section_entry + range_sectors; ic->free_section_entry = next_entry % ic->journal_section_entries; ic->free_section += next_entry / ic->journal_section_entries; ic->n_uncommitted_sections += next_entry / ic->journal_section_entries; -- cgit v1.2.3 From a7c3e62bdc71d33f75803115d44e3ee7dab3d811 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Wed, 19 Jul 2017 11:24:08 -0400 Subject: dm integrity: use plugging when writing the journal When copying data from the journal to the appropriate place, we submit many IOs. Some of these IOs could go to adjacent areas. Use on-stack plugging so that adjacent IOs get merged during submission. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- drivers/md/dm-integrity.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/md') diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index 4b2fd524e38d..be3b6f42095c 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -1823,6 +1823,9 @@ static void do_journal_write(struct dm_integrity_c *ic, unsigned write_start, { unsigned i, j, n; struct journal_completion comp; + struct blk_plug plug; + + blk_start_plug(&plug); comp.ic = ic; comp.in_flight = (atomic_t)ATOMIC_INIT(1); @@ -1947,6 +1950,8 @@ skip_io: dm_bufio_write_dirty_buffers_async(ic->bufio); + blk_finish_plug(&plug); + complete_journal_op(&comp); wait_for_completion_io(&comp.comp); -- cgit v1.2.3 From aa03a91ffaefcffb397cddf88b97215b3eff726d Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Fri, 21 Jul 2017 13:16:06 -0400 Subject: dm integrity: WARN_ON if variables representing journal usage get out of sync If this WARN_ON triggers it speaks to programmer error, and likely implies corruption, but no released kernel should trigger it. This WARN_ON serves to assist DM integrity developers as changes are made/tested in the future. BUG_ON is excessive for catching programmer error, if a user or developer would like warnings to trigger a panic, they can enable that via /proc/sys/kernel/panic_on_warn Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- drivers/md/dm-integrity.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/md') diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index be3b6f42095c..a7a3708700c0 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -1729,6 +1729,8 @@ static void pad_uncommitted(struct dm_integrity_c *ic) wraparound_section(ic, &ic->free_section); ic->n_uncommitted_sections++; } + WARN_ON(ic->journal_sections * ic->journal_section_entries != + (ic->n_uncommitted_sections + ic->n_committed_sections) * ic->journal_section_entries + ic->free_sectors); } static void integrity_commit(struct work_struct *w) -- cgit v1.2.3 From bc86a41e96c5b6f07453c405e036d95acc673389 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Fri, 21 Jul 2017 11:58:38 -0400 Subject: dm integrity: test for corrupted disk format during table load If the dm-integrity superblock was corrupted in such a way that the journal_sections field was zero, the integrity target would deadlock because it would wait forever for free space in the journal. Detect this situation and refuse to activate the device. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Fixes: 7eada909bfd7 ("dm: add integrity target") Signed-off-by: Mike Snitzer --- drivers/md/dm-integrity.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/md') diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index a7a3708700c0..3acce09bba35 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -3028,6 +3028,11 @@ static int dm_integrity_ctr(struct dm_target *ti, unsigned argc, char **argv) ti->error = "Block size doesn't match the information in superblock"; goto bad; } + if (!le32_to_cpu(ic->sb->journal_sections)) { + r = -EINVAL; + ti->error = "Corrupted superblock, journal_sections is 0"; + goto bad; + } /* make sure that ti->max_io_len doesn't overflow */ if (ic->sb->log2_interleave_sectors < MIN_LOG2_INTERLEAVE_SECTORS || ic->sb->log2_interleave_sectors > MAX_LOG2_INTERLEAVE_SECTORS) { -- cgit v1.2.3 From edc11d49f88e3281457853a530c9e5a5540b355a Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Wed, 12 Jul 2017 10:26:34 +0300 Subject: dm bufio: fix error code in dm_bufio_write_dirty_buffers() We should be returning normal negative error codes here. The "a" variables comes from &c->async_write_error which is a blk_status_t converted to a regular error code. In the current code, the blk_status_t gets propogated back to pool_create() and eventually results in an Oops. Fixes: 4e4cbee93d56 ("block: switch bios to blk_status_t") Signed-off-by: Dan Carpenter Reviewed-by: Christoph Hellwig Signed-off-by: Mike Snitzer --- drivers/md/dm-bufio.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index 850ff6c67994..44f4a8ac95bd 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -1258,8 +1258,7 @@ EXPORT_SYMBOL_GPL(dm_bufio_write_dirty_buffers_async); */ int dm_bufio_write_dirty_buffers(struct dm_bufio_client *c) { - blk_status_t a; - int f; + int a, f; unsigned long buffers_processed = 0; struct dm_buffer *b, *tmp; -- cgit v1.2.3 From bbac1e06a415c0658dd328ba9c5f640c2d97be3a Mon Sep 17 00:00:00 2001 From: Heinz Mauelshagen Date: Thu, 13 Jul 2017 17:33:22 +0200 Subject: dm raid: remove WARN_ON() in raid10_md_layout_to_format() Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer --- drivers/md/dm-raid.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 2e10c2f13a34..b409015c6909 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -564,9 +564,10 @@ static const char *raid10_md_layout_to_format(int layout) if (__raid10_near_copies(layout) > 1) return "near"; - WARN_ON(__raid10_far_copies(layout) < 2); + if (__raid10_far_copies(layout) > 1) + return "far"; - return "far"; + return "unknown"; } /* Return md raid10 algorithm for @name */ -- cgit v1.2.3 From f4af3f82daed14ea06ac22eac198a45f56eb2cb1 Mon Sep 17 00:00:00 2001 From: Heinz Mauelshagen Date: Thu, 13 Jul 2017 17:36:12 +0200 Subject: dm raid: fix activation check in validate_raid_redundancy() During growing reshapes (i.e. stripes being added to a raid set), the new stripe images are not in-sync and not part of the raid set until the reshape is started. LVM2 has to request multiple table reloads involving superblock updates in order to reflect proper size of SubLVs in the cluster. Before a stripe adding reshape starts, validate_raid_redundancy() fails as a result of that because it checks the total number of devices against the number of rebuild ones rather than the actual ones in the raid set (as retrieved from the superblock) thus resulting in failed raid4/5/6/10 redundancy checks. E.g. convert 3 stripes -> 7 stripes raid5 (which only allows for maximum 1 device to fail) requesting +4 delta disks causing 4 devices to rebuild during reshaping thus failing activation. To fix this, move validate_raid_redundancy() to get access to the current raid_set members. Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer --- drivers/md/dm-raid.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index b409015c6909..c256a723b964 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -2541,11 +2541,6 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs) if (!freshest) return 0; - if (validate_raid_redundancy(rs)) { - rs->ti->error = "Insufficient redundancy to activate array"; - return -EINVAL; - } - /* * Validation of the freshest device provides the source of * validation for the remaining devices. @@ -2554,6 +2549,11 @@ static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs) if (super_validate(rs, freshest)) return -EINVAL; + if (validate_raid_redundancy(rs)) { + rs->ti->error = "Insufficient redundancy to activate array"; + return -EINVAL; + } + rdev_for_each(rdev, mddev) if (!test_bit(Journal, &rdev->flags) && rdev != freshest && -- cgit v1.2.3 From 0cf352e5a00a0ccf362e4ae60dcaa3318933f6e4 Mon Sep 17 00:00:00 2001 From: Heinz Mauelshagen Date: Thu, 13 Jul 2017 17:34:24 +0200 Subject: dm raid: avoid mddev->suspended access Use runtime flag to ensure that an mddev gets suspended/resumed just once. Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer --- drivers/md/dm-raid.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index c256a723b964..757355b2f1a1 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -208,6 +208,7 @@ struct raid_dev { #define RT_FLAG_RS_BITMAP_LOADED 2 #define RT_FLAG_UPDATE_SBS 3 #define RT_FLAG_RESHAPE_RS 4 +#define RT_FLAG_RS_SUSPENDED 5 /* Array elements of 64 bit needed for rebuild/failed disk bits */ #define DISKS_ARRAY_ELEMS ((MAX_RAID_DEVICES + (sizeof(uint64_t) * 8 - 1)) / sizeof(uint64_t) / 8) @@ -3169,6 +3170,7 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv) } mddev_suspend(&rs->md); + set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags); /* Try to adjust the raid4/5/6 stripe cache size to the stripe size */ if (rs_is_raid456(rs)) { @@ -3626,7 +3628,7 @@ static void raid_postsuspend(struct dm_target *ti) { struct raid_set *rs = ti->private; - if (!rs->md.suspended) + if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) mddev_suspend(&rs->md); rs->md.ro = 1; @@ -3760,7 +3762,7 @@ static int rs_start_reshape(struct raid_set *rs) return r; /* Need to be resumed to be able to start reshape, recovery is frozen until raid_resume() though */ - if (mddev->suspended) + if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) mddev_resume(mddev); /* @@ -3787,8 +3789,8 @@ static int rs_start_reshape(struct raid_set *rs) } /* Suspend because a resume will happen in raid_resume() */ - if (!mddev->suspended) - mddev_suspend(mddev); + set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags); + mddev_suspend(mddev); /* * Now reshape got set up, update superblocks to @@ -3884,7 +3886,7 @@ static void raid_resume(struct dm_target *ti) if (!(rs->ctr_flags & RESUME_STAY_FROZEN_FLAGS)) clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); - if (mddev->suspended) + if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) mddev_resume(mddev); } -- cgit v1.2.3 From ac6a318888f6b94925de603d4563edf7e86e04c8 Mon Sep 17 00:00:00 2001 From: Heinz Mauelshagen Date: Thu, 13 Jul 2017 17:52:18 +0200 Subject: dm raid: bump target version Bumo dm-raid target version to 1.12.1 to reflect that commit cc27b0c78c ("md: fix deadlock between mddev_suspend() and md_write_start()") is available. This version change allows userspace to detect that MD fix is available. Signed-off-by: Heinz Mauelshagen Signed-off-by: Mike Snitzer --- Documentation/device-mapper/dm-raid.txt | 1 + drivers/md/dm-raid.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/md') diff --git a/Documentation/device-mapper/dm-raid.txt b/Documentation/device-mapper/dm-raid.txt index 7e06e65586d4..4a0a7469fdd7 100644 --- a/Documentation/device-mapper/dm-raid.txt +++ b/Documentation/device-mapper/dm-raid.txt @@ -343,3 +343,4 @@ Version History 1.11.0 Fix table line argument order (wrong raid10_copies/raid10_format sequence) 1.11.1 Add raid4/5/6 journal write-back support via journal_mode option +1.12.1 fix for MD deadlock between mddev_suspend() and md_write_start() available diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 757355b2f1a1..5bfe285ea9d1 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -3892,7 +3892,7 @@ static void raid_resume(struct dm_target *ti) static struct target_type raid_target = { .name = "raid", - .version = {1, 11, 1}, + .version = {1, 12, 1}, .module = THIS_MODULE, .ctr = raid_ctr, .dtr = raid_dtr, -- cgit v1.2.3 From edbe9597aca2e2601e6e152bdea200b6cf1b8b47 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Fri, 21 Jul 2017 11:56:46 -0400 Subject: dm zoned: remove test for impossible REQ_OP_FLUSH conditions The value REQ_OP_FLUSH is only used by the block code for request-based devices. Remove the tests for REQ_OP_FLUSH from the bio-based dm-zoned-target. Signed-off-by: Mikulas Patocka Reviewed-by: Damien Le Moal Signed-off-by: Mike Snitzer --- drivers/md/dm-zoned-target.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c index 2b538fa817f4..71eae8a23dae 100644 --- a/drivers/md/dm-zoned-target.c +++ b/drivers/md/dm-zoned-target.c @@ -588,7 +588,7 @@ static int dmz_map(struct dm_target *ti, struct bio *bio) bio->bi_bdev = dev->bdev; - if (!nr_sectors && (bio_op(bio) != REQ_OP_FLUSH) && (bio_op(bio) != REQ_OP_WRITE)) + if (!nr_sectors && bio_op(bio) != REQ_OP_WRITE) return DM_MAPIO_REMAPPED; /* The BIO should be block aligned */ @@ -603,7 +603,7 @@ static int dmz_map(struct dm_target *ti, struct bio *bio) bioctx->status = BLK_STS_OK; /* Set the BIO pending in the flush list */ - if (bio_op(bio) == REQ_OP_FLUSH || (!nr_sectors && bio_op(bio) == REQ_OP_WRITE)) { + if (!nr_sectors && bio_op(bio) == REQ_OP_WRITE) { spin_lock(&dmz->flush_lock); bio_list_add(&dmz->flush_list, bio); spin_unlock(&dmz->flush_lock); -- cgit v1.2.3 From 4218a9554653bd5be6e3c740749282b57434bd73 Mon Sep 17 00:00:00 2001 From: Damien Le Moal Date: Mon, 24 Jul 2017 16:44:37 +0900 Subject: dm zoned: use GFP_NOIO in I/O path Use GFP_NOIO for memory allocations in the I/O path. Other memory allocations in the initialization path can use GFP_KERNEL. Reported-by: Mikulas Patocka Signed-off-by: Damien Le Moal Reviewed-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- drivers/md/dm-zoned-metadata.c | 12 ++++++------ drivers/md/dm-zoned-reclaim.c | 2 +- drivers/md/dm-zoned-target.c | 4 ++-- 3 files changed, 9 insertions(+), 9 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c index 884ff7c170a0..a4fa2ada6883 100644 --- a/drivers/md/dm-zoned-metadata.c +++ b/drivers/md/dm-zoned-metadata.c @@ -624,7 +624,7 @@ static int dmz_write_sb(struct dmz_metadata *zmd, unsigned int set) ret = dmz_rdwr_block(zmd, REQ_OP_WRITE, block, mblk->page); if (ret == 0) - ret = blkdev_issue_flush(zmd->dev->bdev, GFP_KERNEL, NULL); + ret = blkdev_issue_flush(zmd->dev->bdev, GFP_NOIO, NULL); return ret; } @@ -658,7 +658,7 @@ static int dmz_write_dirty_mblocks(struct dmz_metadata *zmd, /* Flush drive cache (this will also sync data) */ if (ret == 0) - ret = blkdev_issue_flush(zmd->dev->bdev, GFP_KERNEL, NULL); + ret = blkdev_issue_flush(zmd->dev->bdev, GFP_NOIO, NULL); return ret; } @@ -722,7 +722,7 @@ int dmz_flush_metadata(struct dmz_metadata *zmd) /* If there are no dirty metadata blocks, just flush the device cache */ if (list_empty(&write_list)) { - ret = blkdev_issue_flush(zmd->dev->bdev, GFP_KERNEL, NULL); + ret = blkdev_issue_flush(zmd->dev->bdev, GFP_NOIO, NULL); goto out; } @@ -927,7 +927,7 @@ static int dmz_recover_mblocks(struct dmz_metadata *zmd, unsigned int dst_set) (zmd->nr_meta_zones << zmd->dev->zone_nr_blocks_shift); } - page = alloc_page(GFP_KERNEL); + page = alloc_page(GFP_NOIO); if (!page) return -ENOMEM; @@ -1183,7 +1183,7 @@ static int dmz_update_zone(struct dmz_metadata *zmd, struct dm_zone *zone) /* Get zone information from disk */ ret = blkdev_report_zones(zmd->dev->bdev, dmz_start_sect(zmd, zone), - &blkz, &nr_blkz, GFP_KERNEL); + &blkz, &nr_blkz, GFP_NOIO); if (ret) { dmz_dev_err(zmd->dev, "Get zone %u report failed", dmz_id(zmd, zone)); @@ -1257,7 +1257,7 @@ static int dmz_reset_zone(struct dmz_metadata *zmd, struct dm_zone *zone) ret = blkdev_reset_zones(dev->bdev, dmz_start_sect(zmd, zone), - dev->zone_nr_sectors, GFP_KERNEL); + dev->zone_nr_sectors, GFP_NOIO); if (ret) { dmz_dev_err(dev, "Reset zone %u failed %d", dmz_id(zmd, zone), ret); diff --git a/drivers/md/dm-zoned-reclaim.c b/drivers/md/dm-zoned-reclaim.c index 05c0a126f5c8..44a119e12f1a 100644 --- a/drivers/md/dm-zoned-reclaim.c +++ b/drivers/md/dm-zoned-reclaim.c @@ -75,7 +75,7 @@ static int dmz_reclaim_align_wp(struct dmz_reclaim *zrc, struct dm_zone *zone, nr_blocks = block - wp_block; ret = blkdev_issue_zeroout(zrc->dev->bdev, dmz_start_sect(zmd, zone) + dmz_blk2sect(wp_block), - dmz_blk2sect(nr_blocks), GFP_NOFS, false); + dmz_blk2sect(nr_blocks), GFP_NOIO, 0); if (ret) { dmz_dev_err(zrc->dev, "Align zone %u wp %llu to %llu (wp+%u) blocks failed %d", diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c index 71eae8a23dae..b08bbbd4d902 100644 --- a/drivers/md/dm-zoned-target.c +++ b/drivers/md/dm-zoned-target.c @@ -541,7 +541,7 @@ static void dmz_queue_chunk_work(struct dmz_target *dmz, struct bio *bio) int ret; /* Create a new chunk work */ - cw = kmalloc(sizeof(struct dm_chunk_work), GFP_NOFS); + cw = kmalloc(sizeof(struct dm_chunk_work), GFP_NOIO); if (!cw) goto out; @@ -785,7 +785,7 @@ static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv) /* Chunk BIO work */ mutex_init(&dmz->chunk_lock); - INIT_RADIX_TREE(&dmz->chunk_rxtree, GFP_NOFS); + INIT_RADIX_TREE(&dmz->chunk_rxtree, GFP_KERNEL); dmz->chunk_wq = alloc_workqueue("dmz_cwq_%s", WQ_MEM_RECLAIM | WQ_UNBOUND, 0, dev->name); if (!dmz->chunk_wq) { -- cgit v1.2.3 From 34c96507e8f6be497c15497be05f489fb34c5880 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 10 Apr 2017 12:13:00 +1000 Subject: dm verity fec: fix GFP flags used with mempool_alloc() mempool_alloc() cannot fail for GFP_NOIO allocation, so there is no point testing for failure. One place the code tested for failure was passing "0" as the GFP flags. This is most unusual and is probably meant to be GFP_NOIO, so that is changed. Also, allocation from ->extra_pool and ->prealloc_pool are repeated before releasing the previous allocation. This can deadlock if the code is servicing a write under high memory pressure. To avoid deadlocks, change these to use GFP_NOWAIT and leave the error handling in place. Signed-off-by: NeilBrown Signed-off-by: Mike Snitzer --- drivers/md/dm-verity-fec.c | 21 +++++---------------- 1 file changed, 5 insertions(+), 16 deletions(-) (limited to 'drivers/md') diff --git a/drivers/md/dm-verity-fec.c b/drivers/md/dm-verity-fec.c index 504ba3fa328b..e13f90832b6b 100644 --- a/drivers/md/dm-verity-fec.c +++ b/drivers/md/dm-verity-fec.c @@ -308,19 +308,14 @@ static int fec_alloc_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio) { unsigned n; - if (!fio->rs) { - fio->rs = mempool_alloc(v->fec->rs_pool, 0); - if (unlikely(!fio->rs)) { - DMERR("failed to allocate RS"); - return -ENOMEM; - } - } + if (!fio->rs) + fio->rs = mempool_alloc(v->fec->rs_pool, GFP_NOIO); fec_for_each_prealloc_buffer(n) { if (fio->bufs[n]) continue; - fio->bufs[n] = mempool_alloc(v->fec->prealloc_pool, GFP_NOIO); + fio->bufs[n] = mempool_alloc(v->fec->prealloc_pool, GFP_NOWAIT); if (unlikely(!fio->bufs[n])) { DMERR("failed to allocate FEC buffer"); return -ENOMEM; @@ -332,22 +327,16 @@ static int fec_alloc_bufs(struct dm_verity *v, struct dm_verity_fec_io *fio) if (fio->bufs[n]) continue; - fio->bufs[n] = mempool_alloc(v->fec->extra_pool, GFP_NOIO); + fio->bufs[n] = mempool_alloc(v->fec->extra_pool, GFP_NOWAIT); /* we can manage with even one buffer if necessary */ if (unlikely(!fio->bufs[n])) break; } fio->nbufs = n; - if (!fio->output) { + if (!fio->output) fio->output = mempool_alloc(v->fec->output_pool, GFP_NOIO); - if (!fio->output) { - DMERR("failed to allocate FEC page"); - return -ENOMEM; - } - } - return 0; } -- cgit v1.2.3 From 273752c9ff03eb83856601b2a3458218bb949e46 Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Wed, 26 Jul 2017 09:35:09 -0400 Subject: dm, dax: Make sure dm_dax_flush() is called if device supports it Currently dm_dax_flush() is not being called, even if underlying dax device supports write cache, because DAXDEV_WRITE_CACHE is not being propagated up to the DM dax device. If the underlying dax device supports write cache, set DAXDEV_WRITE_CACHE on the DM dax device. This will cause dm_dax_flush() to be called. Fixes: abebfbe2f7 ("dm: add ->flush() dax operation support") Signed-off-by: Vivek Goyal Acked-by: Dan Williams Signed-off-by: Mike Snitzer --- drivers/dax/super.c | 6 ++++++ drivers/md/dm-table.c | 35 +++++++++++++++++++++++++++++++++++ include/linux/dax.h | 1 + 3 files changed, 42 insertions(+) (limited to 'drivers/md') diff --git a/drivers/dax/super.c b/drivers/dax/super.c index ce9e563e6e1d..938eb4868f7f 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -278,6 +278,12 @@ void dax_write_cache(struct dax_device *dax_dev, bool wc) } EXPORT_SYMBOL_GPL(dax_write_cache); +bool dax_write_cache_enabled(struct dax_device *dax_dev) +{ + return test_bit(DAXDEV_WRITE_CACHE, &dax_dev->flags); +} +EXPORT_SYMBOL_GPL(dax_write_cache_enabled); + bool dax_alive(struct dax_device *dax_dev) { lockdep_assert_held(&dax_srcu); diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c index a39bcd9b982a..28a4071cdf85 100644 --- a/drivers/md/dm-table.c +++ b/drivers/md/dm-table.c @@ -20,6 +20,7 @@ #include #include #include +#include #define DM_MSG_PREFIX "table" @@ -1630,6 +1631,37 @@ static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush) return false; } +static int device_dax_write_cache_enabled(struct dm_target *ti, + struct dm_dev *dev, sector_t start, + sector_t len, void *data) +{ + struct dax_device *dax_dev = dev->dax_dev; + + if (!dax_dev) + return false; + + if (dax_write_cache_enabled(dax_dev)) + return true; + return false; +} + +static int dm_table_supports_dax_write_cache(struct dm_table *t) +{ + struct dm_target *ti; + unsigned i; + + for (i = 0; i < dm_table_get_num_targets(t); i++) { + ti = dm_table_get_target(t, i); + + if (ti->type->iterate_devices && + ti->type->iterate_devices(ti, + device_dax_write_cache_enabled, NULL)) + return true; + } + + return false; +} + static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev, sector_t start, sector_t len, void *data) { @@ -1785,6 +1817,9 @@ void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, } blk_queue_write_cache(q, wc, fua); + if (dm_table_supports_dax_write_cache(t)) + dax_write_cache(t->md->dax_dev, true); + /* Ensure that all underlying devices are non-rotational. */ if (dm_table_all_devices_attribute(t, device_is_nonrot)) queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q); diff --git a/include/linux/dax.h b/include/linux/dax.h index 794811875732..df97b7af7e2c 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -87,6 +87,7 @@ size_t dax_copy_from_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, void dax_flush(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t size); void dax_write_cache(struct dax_device *dax_dev, bool wc); +bool dax_write_cache_enabled(struct dax_device *dax_dev); /* * We use lowest available bit in exceptional entry for locking, one bit for -- cgit v1.2.3