From 2f03d0c2cd451c7ac2f317079d4ec518f0986b55 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Tue, 5 Mar 2024 15:22:58 +0800 Subject: [PATCH 1/9] md: don't clear MD_RECOVERY_FROZEN for new dm-raid until resume After commit 9dbd1aa3a81c ("dm raid: add reshaping support to the target") raid_ctr() will set MD_RECOVERY_FROZEN before md_run() and expect to keep array frozen until resume. However, md_run() will clear the flag by setting mddev->recovery to 0. Before commit 1baae052cccd ("md: Don't ignore suspended array in md_check_recovery()"), dm-raid actually relied on suspending to prevent starting new sync_thread. Fix this problem by keeping 'MD_RECOVERY_FROZEN' for dm-raid in md_run(). Fixes: 1baae052cccd ("md: Don't ignore suspended array in md_check_recovery()") Fixes: 9dbd1aa3a81c ("dm raid: add reshaping support to the target") Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai Signed-off-by: Xiao Ni Acked-by: Mike Snitzer Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240305072306.2562024-2-yukuai1@huaweicloud.com --- drivers/md/md.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 48ae2b1cb57af..0c4e00e8d485c 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -6062,7 +6062,10 @@ int md_run(struct mddev *mddev) pr_warn("True protection against single-disk failure might be compromised.\n"); } - mddev->recovery = 0; + /* dm-raid expect sync_thread to be frozen until resume */ + if (mddev->gendisk) + mddev->recovery = 0; + /* may be over-ridden by personality */ mddev->resync_max_sectors = mddev->dev_sectors; From 7a2347e284d7ec2f0759be4db60fa7ca937284fc Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Tue, 5 Mar 2024 15:22:59 +0800 Subject: [PATCH 2/9] md: export helpers to stop sync_thread Add new helpers: void md_idle_sync_thread(struct mddev *mddev); void md_frozen_sync_thread(struct mddev *mddev); void md_unfrozen_sync_thread(struct mddev *mddev); The helpers will be used in dm-raid in later patches to fix regressions and prevent calling md_reap_sync_thread() directly. Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai Signed-off-by: Xiao Ni Acked-by: Mike Snitzer Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240305072306.2562024-3-yukuai1@huaweicloud.com --- drivers/md/md.c | 29 +++++++++++++++++++++++++++++ drivers/md/md.h | 3 +++ 2 files changed, 32 insertions(+) diff --git a/drivers/md/md.c b/drivers/md/md.c index 0c4e00e8d485c..0bf2f7a53ed8d 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -4942,6 +4942,35 @@ static void stop_sync_thread(struct mddev *mddev, bool locked, bool check_seq) mddev_lock_nointr(mddev); } +void md_idle_sync_thread(struct mddev *mddev) +{ + lockdep_assert_held(&mddev->reconfig_mutex); + + clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); + stop_sync_thread(mddev, true, true); +} +EXPORT_SYMBOL_GPL(md_idle_sync_thread); + +void md_frozen_sync_thread(struct mddev *mddev) +{ + lockdep_assert_held(&mddev->reconfig_mutex); + + set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); + stop_sync_thread(mddev, true, false); +} +EXPORT_SYMBOL_GPL(md_frozen_sync_thread); + +void md_unfrozen_sync_thread(struct mddev *mddev) +{ + lockdep_assert_held(&mddev->reconfig_mutex); + + clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); + set_bit(MD_RECOVERY_NEEDED, &mddev->recovery); + md_wakeup_thread(mddev->thread); + sysfs_notify_dirent_safe(mddev->sysfs_action); +} +EXPORT_SYMBOL_GPL(md_unfrozen_sync_thread); + static void idle_sync_thread(struct mddev *mddev) { mutex_lock(&mddev->sync_mutex); diff --git a/drivers/md/md.h b/drivers/md/md.h index b2076a165c105..dff2e333756d4 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -792,6 +792,9 @@ extern void md_rdev_clear(struct md_rdev *rdev); extern void md_handle_request(struct mddev *mddev, struct bio *bio); extern int mddev_suspend(struct mddev *mddev, bool interruptible); extern void mddev_resume(struct mddev *mddev); +extern void md_idle_sync_thread(struct mddev *mddev); +extern void md_frozen_sync_thread(struct mddev *mddev); +extern void md_unfrozen_sync_thread(struct mddev *mddev); extern void md_reload_sb(struct mddev *mddev, int raid_disk); extern void md_update_sb(struct mddev *mddev, int force); From 314e9af065513ff86ec9e32eaa96b9bd275cf51d Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Tue, 5 Mar 2024 15:23:00 +0800 Subject: [PATCH 3/9] md: export helper md_is_rdwr() There are no functional changes for now, prepare to fix a deadlock for dm-raid456. Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai Signed-off-by: Xiao Ni Acked-by: Mike Snitzer Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240305072306.2562024-4-yukuai1@huaweicloud.com --- drivers/md/md.c | 12 ------------ drivers/md/md.h | 12 ++++++++++++ 2 files changed, 12 insertions(+), 12 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 0bf2f7a53ed8d..55ecc05c17c65 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -99,18 +99,6 @@ static void mddev_detach(struct mddev *mddev); static void export_rdev(struct md_rdev *rdev, struct mddev *mddev); static void md_wakeup_thread_directly(struct md_thread __rcu *thread); -enum md_ro_state { - MD_RDWR, - MD_RDONLY, - MD_AUTO_READ, - MD_MAX_STATE -}; - -static bool md_is_rdwr(struct mddev *mddev) -{ - return (mddev->ro == MD_RDWR); -} - /* * Default number of read corrections we'll attempt on an rdev * before ejecting it from the array. We divide the read error diff --git a/drivers/md/md.h b/drivers/md/md.h index dff2e333756d4..a40e898fe57e5 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -569,6 +569,18 @@ enum recovery_flags { MD_RESYNCING_REMOTE, /* remote node is running resync thread */ }; +enum md_ro_state { + MD_RDWR, + MD_RDONLY, + MD_AUTO_READ, + MD_MAX_STATE +}; + +static inline bool md_is_rdwr(struct mddev *mddev) +{ + return (mddev->ro == MD_RDWR); +} + static inline int __must_check mddev_lock(struct mddev *mddev) { return mutex_lock_interruptible(&mddev->reconfig_mutex); From 503f9d43790fdd0c6e6ae2f4dd3f70b146ac4159 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Tue, 5 Mar 2024 15:23:01 +0800 Subject: [PATCH 4/9] md: add a new helper reshape_interrupted() The helper will be used for dm-raid456 later to detect the case that reshape can't make progress. Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai Signed-off-by: Xiao Ni Acked-by: Mike Snitzer Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240305072306.2562024-5-yukuai1@huaweicloud.com --- drivers/md/md.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/drivers/md/md.h b/drivers/md/md.h index a40e898fe57e5..d5721bd77f63b 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -581,6 +581,25 @@ static inline bool md_is_rdwr(struct mddev *mddev) return (mddev->ro == MD_RDWR); } +static inline bool reshape_interrupted(struct mddev *mddev) +{ + /* reshape never start */ + if (mddev->reshape_position == MaxSector) + return false; + + /* interrupted */ + if (!test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) + return true; + + /* running reshape will be interrupted soon. */ + if (test_bit(MD_RECOVERY_WAIT, &mddev->recovery) || + test_bit(MD_RECOVERY_INTR, &mddev->recovery) || + test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)) + return true; + + return false; +} + static inline int __must_check mddev_lock(struct mddev *mddev) { return mutex_lock_interruptible(&mddev->reconfig_mutex); From 16c4770c75b1223998adbeb7286f9a15c65fba73 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Tue, 5 Mar 2024 15:23:02 +0800 Subject: [PATCH 5/9] dm-raid: really frozen sync_thread during suspend 1) commit f52f5c71f3d4 ("md: fix stopping sync thread") remove MD_RECOVERY_FROZEN from __md_stop_writes() and doesn't realize that dm-raid relies on __md_stop_writes() to frozen sync_thread indirectly. Fix this problem by adding MD_RECOVERY_FROZEN in md_stop_writes(), and since stop_sync_thread() is only used for dm-raid in this case, also move stop_sync_thread() to md_stop_writes(). 2) The flag MD_RECOVERY_FROZEN doesn't mean that sync thread is frozen, it only prevent new sync_thread to start, and it can't stop the running sync thread; In order to frozen sync_thread, after seting the flag, stop_sync_thread() should be used. 3) The flag MD_RECOVERY_FROZEN doesn't mean that writes are stopped, use it as condition for md_stop_writes() in raid_postsuspend() doesn't look correct. Consider that reentrant stop_sync_thread() do nothing, always call md_stop_writes() in raid_postsuspend(). 4) raid_message can set/clear the flag MD_RECOVERY_FROZEN at anytime, and if MD_RECOVERY_FROZEN is cleared while the array is suspended, new sync_thread can start unexpected. Fix this by disallow raid_message() to change sync_thread status during suspend. Note that after commit f52f5c71f3d4 ("md: fix stopping sync thread"), the test shell/lvconvert-raid-reshape.sh start to hang in stop_sync_thread(), and with previous fixes, the test won't hang there anymore, however, the test will still fail and complain that ext4 is corrupted. And with this patch, the test won't hang due to stop_sync_thread() or fail due to ext4 is corrupted anymore. However, there is still a deadlock related to dm-raid456 that will be fixed in following patches. Reported-by: Mikulas Patocka Closes: https://lore.kernel.org/all/e5e8afe2-e9a8-49a2-5ab0-958d4065c55e@redhat.com/ Fixes: 1af2048a3e87 ("dm raid: fix deadlock caused by premature md_stop_writes()") Fixes: 9dbd1aa3a81c ("dm raid: add reshaping support to the target") Fixes: f52f5c71f3d4 ("md: fix stopping sync thread") Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai Signed-off-by: Xiao Ni Acked-by: Mike Snitzer Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240305072306.2562024-6-yukuai1@huaweicloud.com --- drivers/md/dm-raid.c | 25 +++++++++++++++---------- drivers/md/md.c | 3 ++- 2 files changed, 17 insertions(+), 11 deletions(-) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index eb009d6bb03a1..e2d7a73c0f874 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -3240,11 +3240,12 @@ static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv) rs->md.ro = 1; rs->md.in_sync = 1; - /* Keep array frozen until resume. */ - set_bit(MD_RECOVERY_FROZEN, &rs->md.recovery); - /* Has to be held on running the array */ mddev_suspend_and_lock_nointr(&rs->md); + + /* Keep array frozen until resume. */ + md_frozen_sync_thread(&rs->md); + r = md_run(&rs->md); rs->md.in_sync = 0; /* Assume already marked dirty */ if (r) { @@ -3722,6 +3723,9 @@ static int raid_message(struct dm_target *ti, unsigned int argc, char **argv, if (!mddev->pers || !mddev->pers->sync_request) return -EINVAL; + if (test_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) + return -EBUSY; + if (!strcasecmp(argv[0], "frozen")) set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); else @@ -3796,10 +3800,11 @@ static void raid_postsuspend(struct dm_target *ti) struct raid_set *rs = ti->private; if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) { - /* Writes have to be stopped before suspending to avoid deadlocks. */ - if (!test_bit(MD_RECOVERY_FROZEN, &rs->md.recovery)) - md_stop_writes(&rs->md); - + /* + * sync_thread must be stopped during suspend, and writes have + * to be stopped before suspending to avoid deadlocks. + */ + md_stop_writes(&rs->md); mddev_suspend(&rs->md, false); } } @@ -4012,8 +4017,6 @@ static int raid_preresume(struct dm_target *ti) } /* Check for any resize/reshape on @rs and adjust/initiate */ - /* Be prepared for mddev_resume() in raid_resume() */ - set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); if (mddev->recovery_cp && mddev->recovery_cp < MaxSector) { set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery); mddev->resync_min = mddev->recovery_cp; @@ -4055,10 +4058,12 @@ static void raid_resume(struct dm_target *ti) if (mddev->delta_disks < 0) rs_set_capacity(rs); + WARN_ON_ONCE(!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)); + WARN_ON_ONCE(test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)); mddev_lock_nointr(mddev); - clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); mddev->ro = 0; mddev->in_sync = 0; + md_unfrozen_sync_thread(mddev); mddev_unlock_and_resume(mddev); } } diff --git a/drivers/md/md.c b/drivers/md/md.c index 55ecc05c17c65..167db77442392 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -6364,7 +6364,6 @@ static void md_clean(struct mddev *mddev) static void __md_stop_writes(struct mddev *mddev) { - stop_sync_thread(mddev, true, false); del_timer_sync(&mddev->safemode_timer); if (mddev->pers && mddev->pers->quiesce) { @@ -6389,6 +6388,8 @@ static void __md_stop_writes(struct mddev *mddev) void md_stop_writes(struct mddev *mddev) { mddev_lock_nointr(mddev); + set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); + stop_sync_thread(mddev, true, false); __md_stop_writes(mddev); mddev_unlock(mddev); } From cd32b27a66db8776d8b8e82ec7d7dde97a8693b0 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Tue, 5 Mar 2024 15:23:03 +0800 Subject: [PATCH 6/9] md/dm-raid: don't call md_reap_sync_thread() directly Currently md_reap_sync_thread() is called from raid_message() directly without holding 'reconfig_mutex', this is definitely unsafe because md_reap_sync_thread() can change many fields that is protected by 'reconfig_mutex'. However, hold 'reconfig_mutex' here is still problematic because this will cause deadlock, for example, commit 130443d60b1b ("md: refactor idle/frozen_sync_thread() to fix deadlock"). Fix this problem by using stop_sync_thread() to unregister sync_thread, like md/raid did. Fixes: be83651f0050 ("DM RAID: Add message/status support for changing sync action") Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai Signed-off-by: Xiao Ni Acked-by: Mike Snitzer Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240305072306.2562024-7-yukuai1@huaweicloud.com --- drivers/md/dm-raid.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index e2d7a73c0f874..47c4b1b6e532a 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -3719,6 +3719,7 @@ static int raid_message(struct dm_target *ti, unsigned int argc, char **argv, { struct raid_set *rs = ti->private; struct mddev *mddev = &rs->md; + int ret = 0; if (!mddev->pers || !mddev->pers->sync_request) return -EINVAL; @@ -3726,17 +3727,24 @@ static int raid_message(struct dm_target *ti, unsigned int argc, char **argv, if (test_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) return -EBUSY; - if (!strcasecmp(argv[0], "frozen")) - set_bit(MD_RECOVERY_FROZEN, &mddev->recovery); - else - clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); + if (!strcasecmp(argv[0], "frozen")) { + ret = mddev_lock(mddev); + if (ret) + return ret; - if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) { - if (mddev->sync_thread) { - set_bit(MD_RECOVERY_INTR, &mddev->recovery); - md_reap_sync_thread(mddev); - } - } else if (decipher_sync_action(mddev, mddev->recovery) != st_idle) + md_frozen_sync_thread(mddev); + mddev_unlock(mddev); + } else if (!strcasecmp(argv[0], "idle")) { + ret = mddev_lock(mddev); + if (ret) + return ret; + + md_idle_sync_thread(mddev); + mddev_unlock(mddev); + } + + clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery); + if (decipher_sync_action(mddev, mddev->recovery) != st_idle) return -EBUSY; else if (!strcasecmp(argv[0], "resync")) ; /* MD_RECOVERY_NEEDED set below */ From 5625ff8b72b0e5c13b0fc1fc1f198155af45f729 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Tue, 5 Mar 2024 15:23:04 +0800 Subject: [PATCH 7/9] dm-raid: add a new helper prepare_suspend() in md_personality There are no functional changes for now, prepare to fix a deadlock for dm-raid456. Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai Signed-off-by: Xiao Ni Acked-by: Mike Snitzer Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240305072306.2562024-8-yukuai1@huaweicloud.com --- drivers/md/dm-raid.c | 18 ++++++++++++++++++ drivers/md/md.h | 1 + 2 files changed, 19 insertions(+) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 47c4b1b6e532a..7d48943acd57c 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -3803,6 +3803,23 @@ static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits) blk_limits_io_opt(limits, chunk_size_bytes * mddev_data_stripes(rs)); } +static void raid_presuspend(struct dm_target *ti) +{ + struct raid_set *rs = ti->private; + struct mddev *mddev = &rs->md; + + if (!reshape_interrupted(mddev)) + return; + + /* + * For raid456, if reshape is interrupted, IO across reshape position + * will never make progress, while caller will wait for IO to be done. + * Inform raid456 to handle those IO to prevent deadlock. + */ + if (mddev->pers && mddev->pers->prepare_suspend) + mddev->pers->prepare_suspend(mddev); +} + static void raid_postsuspend(struct dm_target *ti) { struct raid_set *rs = ti->private; @@ -4087,6 +4104,7 @@ static struct target_type raid_target = { .message = raid_message, .iterate_devices = raid_iterate_devices, .io_hints = raid_io_hints, + .presuspend = raid_presuspend, .postsuspend = raid_postsuspend, .preresume = raid_preresume, .resume = raid_resume, diff --git a/drivers/md/md.h b/drivers/md/md.h index d5721bd77f63b..8041df038b5e9 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -659,6 +659,7 @@ struct md_personality int (*start_reshape) (struct mddev *mddev); void (*finish_reshape) (struct mddev *mddev); void (*update_reshape_pos) (struct mddev *mddev); + void (*prepare_suspend) (struct mddev *mddev); /* quiesce suspends or resumes internal processing. * 1 - stop new actions and wait for action io to complete * 0 - return to normal behaviour From 41425f96d7aa59bc865f60f5dda3d7697b555677 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Tue, 5 Mar 2024 15:23:05 +0800 Subject: [PATCH 8/9] dm-raid456, md/raid456: fix a deadlock for dm-raid456 while io concurrent with reshape For raid456, if reshape is still in progress, then IO across reshape position will wait for reshape to make progress. However, for dm-raid, in following cases reshape will never make progress hence IO will hang: 1) the array is read-only; 2) MD_RECOVERY_WAIT is set; 3) MD_RECOVERY_FROZEN is set; After commit c467e97f079f ("md/raid6: use valid sector values to determine if an I/O should wait on the reshape") fix the problem that IO across reshape position doesn't wait for reshape, the dm-raid test shell/lvconvert-raid-reshape.sh start to hang: [root@fedora ~]# cat /proc/979/stack [<0>] wait_woken+0x7d/0x90 [<0>] raid5_make_request+0x929/0x1d70 [raid456] [<0>] md_handle_request+0xc2/0x3b0 [md_mod] [<0>] raid_map+0x2c/0x50 [dm_raid] [<0>] __map_bio+0x251/0x380 [dm_mod] [<0>] dm_submit_bio+0x1f0/0x760 [dm_mod] [<0>] __submit_bio+0xc2/0x1c0 [<0>] submit_bio_noacct_nocheck+0x17f/0x450 [<0>] submit_bio_noacct+0x2bc/0x780 [<0>] submit_bio+0x70/0xc0 [<0>] mpage_readahead+0x169/0x1f0 [<0>] blkdev_readahead+0x18/0x30 [<0>] read_pages+0x7c/0x3b0 [<0>] page_cache_ra_unbounded+0x1ab/0x280 [<0>] force_page_cache_ra+0x9e/0x130 [<0>] page_cache_sync_ra+0x3b/0x110 [<0>] filemap_get_pages+0x143/0xa30 [<0>] filemap_read+0xdc/0x4b0 [<0>] blkdev_read_iter+0x75/0x200 [<0>] vfs_read+0x272/0x460 [<0>] ksys_read+0x7a/0x170 [<0>] __x64_sys_read+0x1c/0x30 [<0>] do_syscall_64+0xc6/0x230 [<0>] entry_SYSCALL_64_after_hwframe+0x6c/0x74 This is because reshape can't make progress. For md/raid, the problem doesn't exist because register new sync_thread doesn't rely on the IO to be done any more: 1) If array is read-only, it can switch to read-write by ioctl/sysfs; 2) md/raid never set MD_RECOVERY_WAIT; 3) If MD_RECOVERY_FROZEN is set, mddev_suspend() doesn't hold 'reconfig_mutex', hence it can be cleared and reshape can continue by sysfs api 'sync_action'. However, I'm not sure yet how to avoid the problem in dm-raid yet. This patch on the one hand make sure raid_message() can't change sync_thread() through raid_message() after presuspend(), on the other hand detect the above 3 cases before wait for IO do be done in dm_suspend(), and let dm-raid requeue those IO. Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai Signed-off-by: Xiao Ni Acked-by: Mike Snitzer Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240305072306.2562024-9-yukuai1@huaweicloud.com --- drivers/md/dm-raid.c | 22 ++++++++++++++++++++-- drivers/md/md.c | 24 ++++++++++++++++++++++-- drivers/md/md.h | 3 ++- drivers/md/raid5.c | 32 ++++++++++++++++++++++++++++++-- 4 files changed, 74 insertions(+), 7 deletions(-) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 7d48943acd57c..ea45f777691ce 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -213,6 +213,7 @@ struct raid_dev { #define RT_FLAG_RS_IN_SYNC 6 #define RT_FLAG_RS_RESYNCING 7 #define RT_FLAG_RS_GROW 8 +#define RT_FLAG_RS_FROZEN 9 /* 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) @@ -3340,7 +3341,8 @@ static int raid_map(struct dm_target *ti, struct bio *bio) if (unlikely(bio_end_sector(bio) > mddev->array_sectors)) return DM_MAPIO_REQUEUE; - md_handle_request(mddev, bio); + if (unlikely(!md_handle_request(mddev, bio))) + return DM_MAPIO_REQUEUE; return DM_MAPIO_SUBMITTED; } @@ -3724,7 +3726,8 @@ static int raid_message(struct dm_target *ti, unsigned int argc, char **argv, if (!mddev->pers || !mddev->pers->sync_request) return -EINVAL; - if (test_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) + if (test_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags) || + test_bit(RT_FLAG_RS_FROZEN, &rs->runtime_flags)) return -EBUSY; if (!strcasecmp(argv[0], "frozen")) { @@ -3808,6 +3811,12 @@ static void raid_presuspend(struct dm_target *ti) struct raid_set *rs = ti->private; struct mddev *mddev = &rs->md; + /* + * From now on, disallow raid_message() to change sync_thread until + * resume, raid_postsuspend() is too late. + */ + set_bit(RT_FLAG_RS_FROZEN, &rs->runtime_flags); + if (!reshape_interrupted(mddev)) return; @@ -3820,6 +3829,13 @@ static void raid_presuspend(struct dm_target *ti) mddev->pers->prepare_suspend(mddev); } +static void raid_presuspend_undo(struct dm_target *ti) +{ + struct raid_set *rs = ti->private; + + clear_bit(RT_FLAG_RS_FROZEN, &rs->runtime_flags); +} + static void raid_postsuspend(struct dm_target *ti) { struct raid_set *rs = ti->private; @@ -4085,6 +4101,7 @@ static void raid_resume(struct dm_target *ti) WARN_ON_ONCE(!test_bit(MD_RECOVERY_FROZEN, &mddev->recovery)); WARN_ON_ONCE(test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)); + clear_bit(RT_FLAG_RS_FROZEN, &rs->runtime_flags); mddev_lock_nointr(mddev); mddev->ro = 0; mddev->in_sync = 0; @@ -4105,6 +4122,7 @@ static struct target_type raid_target = { .iterate_devices = raid_iterate_devices, .io_hints = raid_io_hints, .presuspend = raid_presuspend, + .presuspend_undo = raid_presuspend_undo, .postsuspend = raid_postsuspend, .preresume = raid_preresume, .resume = raid_resume, diff --git a/drivers/md/md.c b/drivers/md/md.c index 167db77442392..64d544f09295c 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -366,7 +366,7 @@ static bool is_suspended(struct mddev *mddev, struct bio *bio) return true; } -void md_handle_request(struct mddev *mddev, struct bio *bio) +bool md_handle_request(struct mddev *mddev, struct bio *bio) { check_suspended: if (is_suspended(mddev, bio)) { @@ -374,7 +374,7 @@ void md_handle_request(struct mddev *mddev, struct bio *bio) /* Bail out if REQ_NOWAIT is set for the bio */ if (bio->bi_opf & REQ_NOWAIT) { bio_wouldblock_error(bio); - return; + return true; } for (;;) { prepare_to_wait(&mddev->sb_wait, &__wait, @@ -390,10 +390,13 @@ void md_handle_request(struct mddev *mddev, struct bio *bio) if (!mddev->pers->make_request(mddev, bio)) { percpu_ref_put(&mddev->active_io); + if (!mddev->gendisk && mddev->pers->prepare_suspend) + return false; goto check_suspended; } percpu_ref_put(&mddev->active_io); + return true; } EXPORT_SYMBOL(md_handle_request); @@ -8733,6 +8736,23 @@ void md_account_bio(struct mddev *mddev, struct bio **bio) } EXPORT_SYMBOL_GPL(md_account_bio); +void md_free_cloned_bio(struct bio *bio) +{ + struct md_io_clone *md_io_clone = bio->bi_private; + struct bio *orig_bio = md_io_clone->orig_bio; + struct mddev *mddev = md_io_clone->mddev; + + if (bio->bi_status && !orig_bio->bi_status) + orig_bio->bi_status = bio->bi_status; + + if (md_io_clone->start_time) + bio_end_io_acct(orig_bio, md_io_clone->start_time); + + bio_put(bio); + percpu_ref_put(&mddev->active_io); +} +EXPORT_SYMBOL_GPL(md_free_cloned_bio); + /* md_allow_write(mddev) * Calling this ensures that the array is marked 'active' so that writes * may proceed without blocking. It is important to call this before diff --git a/drivers/md/md.h b/drivers/md/md.h index 8041df038b5e9..556db28a49aae 100644 --- a/drivers/md/md.h +++ b/drivers/md/md.h @@ -793,6 +793,7 @@ extern void md_finish_reshape(struct mddev *mddev); void md_submit_discard_bio(struct mddev *mddev, struct md_rdev *rdev, struct bio *bio, sector_t start, sector_t size); void md_account_bio(struct mddev *mddev, struct bio **bio); +void md_free_cloned_bio(struct bio *bio); extern bool __must_check md_flush_request(struct mddev *mddev, struct bio *bio); extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev, @@ -821,7 +822,7 @@ extern void md_stop_writes(struct mddev *mddev); extern int md_rdev_init(struct md_rdev *rdev); extern void md_rdev_clear(struct md_rdev *rdev); -extern void md_handle_request(struct mddev *mddev, struct bio *bio); +extern bool md_handle_request(struct mddev *mddev, struct bio *bio); extern int mddev_suspend(struct mddev *mddev, bool interruptible); extern void mddev_resume(struct mddev *mddev); extern void md_idle_sync_thread(struct mddev *mddev); diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 48129de21aecc..388da55e274e2 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -760,6 +760,7 @@ enum stripe_result { STRIPE_RETRY, STRIPE_SCHEDULE_AND_RETRY, STRIPE_FAIL, + STRIPE_WAIT_RESHAPE, }; struct stripe_request_ctx { @@ -5937,7 +5938,8 @@ static enum stripe_result make_stripe_request(struct mddev *mddev, if (ahead_of_reshape(mddev, logical_sector, conf->reshape_safe)) { spin_unlock_irq(&conf->device_lock); - return STRIPE_SCHEDULE_AND_RETRY; + ret = STRIPE_SCHEDULE_AND_RETRY; + goto out; } } spin_unlock_irq(&conf->device_lock); @@ -6016,6 +6018,12 @@ static enum stripe_result make_stripe_request(struct mddev *mddev, out_release: raid5_release_stripe(sh); +out: + if (ret == STRIPE_SCHEDULE_AND_RETRY && reshape_interrupted(mddev)) { + bi->bi_status = BLK_STS_RESOURCE; + ret = STRIPE_WAIT_RESHAPE; + pr_err_ratelimited("dm-raid456: io across reshape position while reshape can't make progress"); + } return ret; } @@ -6137,7 +6145,7 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi) while (1) { res = make_stripe_request(mddev, conf, &ctx, logical_sector, bi); - if (res == STRIPE_FAIL) + if (res == STRIPE_FAIL || res == STRIPE_WAIT_RESHAPE) break; if (res == STRIPE_RETRY) @@ -6175,6 +6183,11 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi) if (rw == WRITE) md_write_end(mddev); + if (res == STRIPE_WAIT_RESHAPE) { + md_free_cloned_bio(bi); + return false; + } + bio_endio(bi); return true; } @@ -8925,6 +8938,18 @@ static int raid5_start(struct mddev *mddev) return r5l_start(conf->log); } +/* + * This is only used for dm-raid456, caller already frozen sync_thread, hence + * if rehsape is still in progress, io that is waiting for reshape can never be + * done now, hence wake up and handle those IO. + */ +static void raid5_prepare_suspend(struct mddev *mddev) +{ + struct r5conf *conf = mddev->private; + + wake_up(&conf->wait_for_overlap); +} + static struct md_personality raid6_personality = { .name = "raid6", @@ -8948,6 +8973,7 @@ static struct md_personality raid6_personality = .quiesce = raid5_quiesce, .takeover = raid6_takeover, .change_consistency_policy = raid5_change_consistency_policy, + .prepare_suspend = raid5_prepare_suspend, }; static struct md_personality raid5_personality = { @@ -8972,6 +8998,7 @@ static struct md_personality raid5_personality = .quiesce = raid5_quiesce, .takeover = raid5_takeover, .change_consistency_policy = raid5_change_consistency_policy, + .prepare_suspend = raid5_prepare_suspend, }; static struct md_personality raid4_personality = @@ -8997,6 +9024,7 @@ static struct md_personality raid4_personality = .quiesce = raid5_quiesce, .takeover = raid4_takeover, .change_consistency_policy = raid5_change_consistency_policy, + .prepare_suspend = raid5_prepare_suspend, }; static int __init raid5_init(void) From 95009ae904b1e9dca8db6f649f2d7c18a6e42c75 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Tue, 5 Mar 2024 15:23:06 +0800 Subject: [PATCH 9/9] dm-raid: fix lockdep waring in "pers->hot_add_disk" The lockdep assert is added by commit a448af25becf ("md/raid10: remove rcu protection to access rdev from conf") in print_conf(). And I didn't notice that dm-raid is calling "pers->hot_add_disk" without holding 'reconfig_mutex'. "pers->hot_add_disk" read and write many fields that is protected by 'reconfig_mutex', and raid_resume() already grab the lock in other contex. Hence fix this problem by protecting "pers->host_add_disk" with the lock. Fixes: 9092c02d9435 ("DM RAID: Add ability to restore transiently failed devices on resume") Fixes: a448af25becf ("md/raid10: remove rcu protection to access rdev from conf") Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Yu Kuai Signed-off-by: Xiao Ni Acked-by: Mike Snitzer Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20240305072306.2562024-10-yukuai1@huaweicloud.com --- drivers/md/dm-raid.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index ea45f777691ce..17e9af60bbf7f 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -4091,7 +4091,9 @@ static void raid_resume(struct dm_target *ti) * Take this opportunity to check whether any failed * devices are reachable again. */ + mddev_lock_nointr(mddev); attempt_restore_of_faulty_devices(rs); + mddev_unlock(mddev); } if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {