From a27a94c2b0c727517c17cf2ca3a9f7291caadfbc Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Mon, 3 Sep 2018 12:46:14 +0300 Subject: btrfs: Make btrfs_find_device_by_devspec return btrfs_device directly Instead of returning an error value and using one of the parameters for returning the actual object we are interested in just refactor the function to directly return btrfs_device *. Also bubble up the error handling for the special BTRFS_ERROR_DEV_MISSING_NOT_FOUND value into btrfs_rm_device. No functional changes. Signed-off-by: Nikolay Borisov Reviewed-by: Qu Wenruo Signed-off-by: David Sterba --- fs/btrfs/dev-replace.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'fs/btrfs/dev-replace.c') diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index dec01970d8c5..4e2b67d06305 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -409,10 +409,10 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, struct btrfs_device *tgt_device = NULL; struct btrfs_device *src_device = NULL; - ret = btrfs_find_device_by_devspec(fs_info, srcdevid, - srcdev_name, &src_device); - if (ret) - return ret; + src_device = btrfs_find_device_by_devspec(fs_info, srcdevid, + srcdev_name); + if (IS_ERR(src_device)) + return PTR_ERR(src_device); ret = btrfs_init_dev_replace_tgtdev(fs_info, tgtdev_name, src_device, &tgt_device); -- cgit v1.2.3 From 5c06147128fbbdf7a84232c5f0d808f53153defe Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Thu, 6 Sep 2018 15:52:17 -0400 Subject: btrfs: fix error handling in btrfs_dev_replace_start When we fail to start a transaction in btrfs_dev_replace_start, we leave dev_replace->replace_start set to STARTED but clear ->srcdev and ->tgtdev. Later, that can result in an Oops in btrfs_dev_replace_progress when having state set to STARTED or SUSPENDED implies that ->srcdev is valid. Also fix error handling when the state is already STARTED or SUSPENDED while starting. That, too, will clear ->srcdev and ->tgtdev even though it doesn't own them. This should be an impossible case to hit since we should be protected by the BTRFS_FS_EXCL_OP bit being set. Let's add an ASSERT there while we're at it. Fixes: e93c89c1aaaaa (Btrfs: add new sources for device replace code) CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Jeff Mahoney Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/dev-replace.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/dev-replace.c') diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index 4e2b67d06305..ff01740158aa 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -440,6 +440,7 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, break; case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED: case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED: + ASSERT(0); ret = BTRFS_IOCTL_DEV_REPLACE_RESULT_ALREADY_STARTED; goto leave; } @@ -482,6 +483,10 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, if (IS_ERR(trans)) { ret = PTR_ERR(trans); btrfs_dev_replace_write_lock(dev_replace); + dev_replace->replace_state = + BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED; + dev_replace->srcdev = NULL; + dev_replace->tgtdev = NULL; goto leave; } @@ -503,8 +508,6 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, return ret; leave: - dev_replace->srcdev = NULL; - dev_replace->tgtdev = NULL; btrfs_dev_replace_write_unlock(dev_replace); btrfs_destroy_dev_replace_tgtdev(tgt_device); return ret; -- cgit v1.2.3 From 3280f874576d31b03fe19cbcc23585d96feb4ceb Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 24 Aug 2018 17:32:29 +0200 Subject: btrfs: remove btrfs_dev_replace::read_locks This member seems to be copied from the extent_buffer locking scheme and is at least used to assert that the read lock/unlock is properly nested. In some way. While the _inc/_dec are called inside the read lock section, the asserts are both inside and outside, so the ordering is not guaranteed and we can see read/inc/dec ordered in any way (theoretically). A missing call of btrfs_dev_replace_clear_lock_blocking could cause unexpected read_locks count, so this at least looks like a valid assertion, but this will become unnecessary with later updates. Reviewed-by: Anand Jain Signed-off-by: David Sterba --- fs/btrfs/ctree.h | 1 - fs/btrfs/dev-replace.c | 5 ----- fs/btrfs/disk-io.c | 1 - 3 files changed, 7 deletions(-) (limited to 'fs/btrfs/dev-replace.c') diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 36ade217e462..daa273c7e150 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -361,7 +361,6 @@ struct btrfs_dev_replace { struct mutex lock_finishing_cancel_unmount; rwlock_t lock; - atomic_t read_locks; atomic_t blocking_readers; wait_queue_head_t read_lock_wq; diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index ff01740158aa..702fe6a65075 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -964,13 +964,10 @@ int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) void btrfs_dev_replace_read_lock(struct btrfs_dev_replace *dev_replace) { read_lock(&dev_replace->lock); - atomic_inc(&dev_replace->read_locks); } void btrfs_dev_replace_read_unlock(struct btrfs_dev_replace *dev_replace) { - ASSERT(atomic_read(&dev_replace->read_locks) > 0); - atomic_dec(&dev_replace->read_locks); read_unlock(&dev_replace->lock); } @@ -997,7 +994,6 @@ void btrfs_dev_replace_set_lock_blocking( struct btrfs_dev_replace *dev_replace) { /* only set blocking for read lock */ - ASSERT(atomic_read(&dev_replace->read_locks) > 0); atomic_inc(&dev_replace->blocking_readers); read_unlock(&dev_replace->lock); } @@ -1007,7 +1003,6 @@ void btrfs_dev_replace_clear_lock_blocking( struct btrfs_dev_replace *dev_replace) { /* only set blocking for read lock */ - ASSERT(atomic_read(&dev_replace->read_locks) > 0); ASSERT(atomic_read(&dev_replace->blocking_readers) > 0); read_lock(&dev_replace->lock); /* Barrier implied by atomic_dec_and_test */ diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 517484ecad96..79903243877b 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2155,7 +2155,6 @@ static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info) { mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount); rwlock_init(&fs_info->dev_replace.lock); - atomic_set(&fs_info->dev_replace.read_locks, 0); atomic_set(&fs_info->dev_replace.blocking_readers, 0); init_waitqueue_head(&fs_info->replace_wait); init_waitqueue_head(&fs_info->dev_replace.read_lock_wq); -- cgit v1.2.3 From 7fb2eced105f67676eb86473d5b1ce6a96f6eab4 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 24 Aug 2018 17:33:58 +0200 Subject: btrfs: open code btrfs_dev_replace_clear_lock_blocking There's a single caller and the function name does not say it's actually taking the lock, so open coding makes it more explicit. For now, btrfs_dev_replace_read_lock is used instead of read_lock so it's paired with the unlocking wrapper in the same block. Reviewed-by: Anand Jain Signed-off-by: David Sterba --- fs/btrfs/dev-replace.c | 12 ------------ fs/btrfs/dev-replace.h | 2 -- fs/btrfs/volumes.c | 6 +++++- 3 files changed, 5 insertions(+), 15 deletions(-) (limited to 'fs/btrfs/dev-replace.c') diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index 702fe6a65075..a79e8d67f768 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -998,18 +998,6 @@ void btrfs_dev_replace_set_lock_blocking( read_unlock(&dev_replace->lock); } -/* acquire read lock and dec blocking cnt */ -void btrfs_dev_replace_clear_lock_blocking( - struct btrfs_dev_replace *dev_replace) -{ - /* only set blocking for read lock */ - ASSERT(atomic_read(&dev_replace->blocking_readers) > 0); - read_lock(&dev_replace->lock); - /* Barrier implied by atomic_dec_and_test */ - if (atomic_dec_and_test(&dev_replace->blocking_readers)) - cond_wake_up_nomb(&dev_replace->read_lock_wq); -} - void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) { percpu_counter_inc(&fs_info->bio_counter); diff --git a/fs/btrfs/dev-replace.h b/fs/btrfs/dev-replace.h index b6d4206188bb..39f022c457ff 100644 --- a/fs/btrfs/dev-replace.h +++ b/fs/btrfs/dev-replace.h @@ -28,8 +28,6 @@ void btrfs_dev_replace_read_unlock(struct btrfs_dev_replace *dev_replace); void btrfs_dev_replace_write_lock(struct btrfs_dev_replace *dev_replace); void btrfs_dev_replace_write_unlock(struct btrfs_dev_replace *dev_replace); void btrfs_dev_replace_set_lock_blocking(struct btrfs_dev_replace *dev_replace); -void btrfs_dev_replace_clear_lock_blocking( - struct btrfs_dev_replace *dev_replace); static inline void btrfs_dev_replace_stats_inc(atomic64_t *stat_value) { diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 26eb388db343..f435d397019e 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -5904,7 +5904,11 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, } out: if (dev_replace_is_ongoing) { - btrfs_dev_replace_clear_lock_blocking(dev_replace); + ASSERT(atomic_read(&dev_replace->blocking_readers) > 0); + btrfs_dev_replace_read_lock(dev_replace); + /* Barrier implied by atomic_dec_and_test */ + if (atomic_dec_and_test(&dev_replace->blocking_readers)) + cond_wake_up_nomb(&dev_replace->read_lock_wq); btrfs_dev_replace_read_unlock(dev_replace); } free_extent_map(em); -- cgit v1.2.3 From 9f6cbcbb09d0f2a73ccb9998f6ac34606da9c938 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 24 Aug 2018 17:41:17 +0200 Subject: btrfs: open code btrfs_after_dev_replace_commit Too trivial, the purpose can be simply documented in a comment. Reviewed-by: Omar Sandoval Reviewed-by: Anand Jain Signed-off-by: David Sterba --- fs/btrfs/dev-replace.c | 8 -------- fs/btrfs/dev-replace.h | 1 - fs/btrfs/transaction.c | 5 ++++- 3 files changed, 4 insertions(+), 10 deletions(-) (limited to 'fs/btrfs/dev-replace.c') diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index a79e8d67f768..264105a26e7e 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -382,14 +382,6 @@ out: return ret; } -void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info) -{ - struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace; - - dev_replace->committed_cursor_left = - dev_replace->cursor_left_last_write_of_item; -} - static char* btrfs_dev_name(struct btrfs_device *device) { if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) diff --git a/fs/btrfs/dev-replace.h b/fs/btrfs/dev-replace.h index 1c91bf9ef39a..795c551f5b5e 100644 --- a/fs/btrfs/dev-replace.h +++ b/fs/btrfs/dev-replace.h @@ -11,7 +11,6 @@ struct btrfs_ioctl_dev_replace_args; int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info); int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info); -void btrfs_after_dev_replace_commit(struct btrfs_fs_info *fs_info); int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info, struct btrfs_ioctl_dev_replace_args *args); int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 3b1cc978d409..cadc747292d9 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -1198,7 +1198,10 @@ again: list_add_tail(&fs_info->extent_root->dirty_list, &trans->transaction->switch_commits); - btrfs_after_dev_replace_commit(fs_info); + + /* Update dev-replace pointer once everything is committed */ + fs_info->dev_replace.committed_cursor_left = + fs_info->dev_replace.cursor_left_last_write_of_item; return 0; } -- cgit v1.2.3 From aa144bfeaa7f87c536ab323edfe2692285343e68 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 24 Aug 2018 17:44:05 +0200 Subject: btrfs: dev-replace: avoid useless lock on error handling path The exit sequence in btrfs_dev_replace_start does not allow to simply add a label to the right place so the error handling after starting transaction failure jumps there. Currently there's a lock that pairs with the unlock in the section, which is unnecessary and only raises questions. Add a variable to track the locking status and avoid the extra locking. Reviewed-by: Omar Sandoval Reviewed-by: Anand Jain Signed-off-by: David Sterba --- fs/btrfs/dev-replace.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'fs/btrfs/dev-replace.c') diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index 264105a26e7e..c7f2d6b91a6f 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -400,6 +400,7 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, int ret; struct btrfs_device *tgt_device = NULL; struct btrfs_device *src_device = NULL; + bool need_unlock; src_device = btrfs_find_device_by_devspec(fs_info, srcdevid, srcdev_name); @@ -424,6 +425,7 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, return PTR_ERR(trans); } + need_unlock = true; btrfs_dev_replace_write_lock(dev_replace); switch (dev_replace->replace_state) { case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: @@ -463,6 +465,7 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, atomic64_set(&dev_replace->num_write_errors, 0); atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0); btrfs_dev_replace_write_unlock(dev_replace); + need_unlock = false; ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device); if (ret) @@ -474,6 +477,7 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, trans = btrfs_start_transaction(root, 0); if (IS_ERR(trans)) { ret = PTR_ERR(trans); + need_unlock = true; btrfs_dev_replace_write_lock(dev_replace); dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED; @@ -500,7 +504,8 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, return ret; leave: - btrfs_dev_replace_write_unlock(dev_replace); + if (need_unlock) + btrfs_dev_replace_write_unlock(dev_replace); btrfs_destroy_dev_replace_tgtdev(tgt_device); return ret; } -- cgit v1.2.3 From 7f8d236ae132a8886a0186008c828e21f7460474 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Thu, 5 Apr 2018 01:04:49 +0200 Subject: btrfs: dev-replace: move replace members out of fs_info The replace_wait and bio_counter were mistakenly added to fs_info in commit c404e0dc2c843b154f ("Btrfs: fix use-after-free in the finishing procedure of the device replace"), but they logically belong to fs_info::dev_replace. Besides, bio_counter is a very generic name and is confusing in bare fs_info context. Reviewed-by: Anand Jain Signed-off-by: David Sterba --- fs/btrfs/ctree.h | 6 +++--- fs/btrfs/dev-replace.c | 16 ++++++++-------- fs/btrfs/disk-io.c | 9 +++++---- 3 files changed, 16 insertions(+), 15 deletions(-) (limited to 'fs/btrfs/dev-replace.c') diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index daa273c7e150..e8244c0b0597 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -365,6 +365,9 @@ struct btrfs_dev_replace { wait_queue_head_t read_lock_wq; struct btrfs_scrub_progress scrub_progress; + + struct percpu_counter bio_counter; + wait_queue_head_t replace_wait; }; /* For raid type sysfs entries */ @@ -1087,9 +1090,6 @@ struct btrfs_fs_info { /* device replace state */ struct btrfs_dev_replace dev_replace; - struct percpu_counter bio_counter; - wait_queue_head_t replace_wait; - struct semaphore uuid_tree_rescan_sem; /* Used to reclaim the metadata space in the background. */ diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index c7f2d6b91a6f..d1ea76bccaaf 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -545,8 +545,8 @@ int btrfs_dev_replace_by_ioctl(struct btrfs_fs_info *fs_info, static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) { set_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); - wait_event(fs_info->replace_wait, !percpu_counter_sum( - &fs_info->bio_counter)); + wait_event(fs_info->dev_replace.replace_wait, !percpu_counter_sum( + &fs_info->dev_replace.bio_counter)); } /* @@ -555,7 +555,7 @@ static void btrfs_rm_dev_replace_blocked(struct btrfs_fs_info *fs_info) static void btrfs_rm_dev_replace_unblocked(struct btrfs_fs_info *fs_info) { clear_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state); - wake_up(&fs_info->replace_wait); + wake_up(&fs_info->dev_replace.replace_wait); } static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, @@ -997,25 +997,25 @@ void btrfs_dev_replace_set_lock_blocking( void btrfs_bio_counter_inc_noblocked(struct btrfs_fs_info *fs_info) { - percpu_counter_inc(&fs_info->bio_counter); + percpu_counter_inc(&fs_info->dev_replace.bio_counter); } void btrfs_bio_counter_sub(struct btrfs_fs_info *fs_info, s64 amount) { - percpu_counter_sub(&fs_info->bio_counter, amount); - cond_wake_up_nomb(&fs_info->replace_wait); + percpu_counter_sub(&fs_info->dev_replace.bio_counter, amount); + cond_wake_up_nomb(&fs_info->dev_replace.replace_wait); } void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info) { while (1) { - percpu_counter_inc(&fs_info->bio_counter); + percpu_counter_inc(&fs_info->dev_replace.bio_counter); if (likely(!test_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state))) break; btrfs_bio_counter_dec(fs_info); - wait_event(fs_info->replace_wait, + wait_event(fs_info->dev_replace.replace_wait, !test_bit(BTRFS_FS_STATE_DEV_REPLACING, &fs_info->fs_state)); } diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 79903243877b..27f6a3348f94 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2156,7 +2156,7 @@ static void btrfs_init_dev_replace_locks(struct btrfs_fs_info *fs_info) mutex_init(&fs_info->dev_replace.lock_finishing_cancel_unmount); rwlock_init(&fs_info->dev_replace.lock); atomic_set(&fs_info->dev_replace.blocking_readers, 0); - init_waitqueue_head(&fs_info->replace_wait); + init_waitqueue_head(&fs_info->dev_replace.replace_wait); init_waitqueue_head(&fs_info->dev_replace.read_lock_wq); } @@ -2646,7 +2646,8 @@ int open_ctree(struct super_block *sb, goto fail_dirty_metadata_bytes; } - ret = percpu_counter_init(&fs_info->bio_counter, 0, GFP_KERNEL); + ret = percpu_counter_init(&fs_info->dev_replace.bio_counter, 0, + GFP_KERNEL); if (ret) { err = ret; goto fail_delalloc_bytes; @@ -3307,7 +3308,7 @@ fail_iput: iput(fs_info->btree_inode); fail_bio_counter: - percpu_counter_destroy(&fs_info->bio_counter); + percpu_counter_destroy(&fs_info->dev_replace.bio_counter); fail_delalloc_bytes: percpu_counter_destroy(&fs_info->delalloc_bytes); fail_dirty_metadata_bytes: @@ -4016,7 +4017,7 @@ void close_ctree(struct btrfs_fs_info *fs_info) percpu_counter_destroy(&fs_info->dirty_metadata_bytes); percpu_counter_destroy(&fs_info->delalloc_bytes); - percpu_counter_destroy(&fs_info->bio_counter); + percpu_counter_destroy(&fs_info->dev_replace.bio_counter); cleanup_srcu_struct(&fs_info->subvol_srcu); btrfs_free_stripe_hash_table(fs_info); -- cgit v1.2.3 From 9b142115ed3593480b813a9331593e9f199da340 Mon Sep 17 00:00:00 2001 From: David Sterba Date: Thu, 5 Apr 2018 01:19:50 +0200 Subject: btrfs: dev-replace: remove pointless assert in write unlock The value of blocking_readers is increased only when the lock is taken for read, no way we can fail the condition with the write lock. Reviewed-by: Anand Jain Signed-off-by: David Sterba --- fs/btrfs/dev-replace.c | 1 - 1 file changed, 1 deletion(-) (limited to 'fs/btrfs/dev-replace.c') diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index d1ea76bccaaf..2aa48aecc52b 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -982,7 +982,6 @@ again: void btrfs_dev_replace_write_unlock(struct btrfs_dev_replace *dev_replace) { - ASSERT(atomic_read(&dev_replace->blocking_readers) == 0); write_unlock(&dev_replace->lock); } -- cgit v1.2.3