Commit 7e79cb86 authored by David Sterba's avatar David Sterba
Browse files

btrfs: split dev-replace locking helpers for read and write 



The current calls are unclear in what way btrfs_dev_replace_lock takes
the locks, so drop the argument, split the helpers and use similar
naming as for read and write locks.

Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent e7ab0af6

fs/btrfs/dev-replace.c

+49 −49
Original line number Diff line number Diff line
@@ -205,13 +205,13 @@ int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, 
	struct btrfs_dev_replace_item *ptr;

	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;



	btrfs_dev_replace_lock(dev_replace, 0);

	btrfs_dev_replace_read_lock(dev_replace);

	if (!dev_replace->is_valid ||

	    !dev_replace->item_needs_writeback) {

		btrfs_dev_replace_unlock(dev_replace, 0);

		btrfs_dev_replace_read_unlock(dev_replace);

		return 0;

	}

	btrfs_dev_replace_unlock(dev_replace, 0);

	btrfs_dev_replace_read_unlock(dev_replace);



	key.objectid = 0;

	key.type = BTRFS_DEV_REPLACE_KEY;
@@ -269,7 +269,7 @@ int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, 
	ptr = btrfs_item_ptr(eb, path->slots[0],

			     struct btrfs_dev_replace_item);



	btrfs_dev_replace_lock(dev_replace, 1);

	btrfs_dev_replace_write_lock(dev_replace);

	if (dev_replace->srcdev)

		btrfs_set_dev_replace_src_devid(eb, ptr,

			dev_replace->srcdev->devid);
@@ -292,7 +292,7 @@ int btrfs_run_dev_replace(struct btrfs_trans_handle *trans, 
	btrfs_set_dev_replace_cursor_right(eb, ptr,

		dev_replace->cursor_right);

	dev_replace->item_needs_writeback = 0;

	btrfs_dev_replace_unlock(dev_replace, 1);

	btrfs_dev_replace_write_unlock(dev_replace);



	btrfs_mark_buffer_dirty(eb);
@@ -357,7 +357,7 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 
		return PTR_ERR(trans);

	}



	btrfs_dev_replace_lock(dev_replace, 1);

	btrfs_dev_replace_write_lock(dev_replace);

	switch (dev_replace->replace_state) {

	case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:

	case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
@@ -395,7 +395,7 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 
	dev_replace->item_needs_writeback = 1;

	atomic64_set(&dev_replace->num_write_errors, 0);

	atomic64_set(&dev_replace->num_uncorrectable_read_errors, 0);

	btrfs_dev_replace_unlock(dev_replace, 1);

	btrfs_dev_replace_write_unlock(dev_replace);



	ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device);

	if (ret)
@@ -407,7 +407,7 @@ 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);

		btrfs_dev_replace_lock(dev_replace, 1);

		btrfs_dev_replace_write_lock(dev_replace);

		goto leave;

	}
@@ -431,7 +431,7 @@ int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 
leave:

	dev_replace->srcdev = NULL;

	dev_replace->tgtdev = NULL;

	btrfs_dev_replace_unlock(dev_replace, 1);

	btrfs_dev_replace_write_unlock(dev_replace);

	btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);

	return ret;

}
@@ -498,18 +498,18 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 
	/* don't allow cancel or unmount to disturb the finishing procedure */

	mutex_lock(&dev_replace->lock_finishing_cancel_unmount);



	btrfs_dev_replace_lock(dev_replace, 0);

	btrfs_dev_replace_read_lock(dev_replace);

	/* was the operation canceled, or is it finished? */

	if (dev_replace->replace_state !=

	    BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED) {

		btrfs_dev_replace_unlock(dev_replace, 0);

		btrfs_dev_replace_read_unlock(dev_replace);

		mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);

		return 0;

	}



	tgt_device = dev_replace->tgtdev;

	src_device = dev_replace->srcdev;

	btrfs_dev_replace_unlock(dev_replace, 0);

	btrfs_dev_replace_read_unlock(dev_replace);



	/*

	 * flush all outstanding I/O and inode extent mappings before the
@@ -534,7 +534,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 
	/* keep away write_all_supers() during the finishing procedure */

	mutex_lock(&fs_info->fs_devices->device_list_mutex);

	mutex_lock(&fs_info->chunk_mutex);

	btrfs_dev_replace_lock(dev_replace, 1);

	btrfs_dev_replace_write_lock(dev_replace);

	dev_replace->replace_state =

		scrub_ret ? BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED

			  : BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED;
@@ -554,7 +554,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 
				 btrfs_dev_name(src_device),

				 src_device->devid,

				 rcu_str_deref(tgt_device->name), scrub_ret);

		btrfs_dev_replace_unlock(dev_replace, 1);

		btrfs_dev_replace_write_unlock(dev_replace);

		mutex_unlock(&fs_info->chunk_mutex);

		mutex_unlock(&fs_info->fs_devices->device_list_mutex);

		mutex_unlock(&uuid_mutex);
@@ -591,7 +591,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 
	list_add(&tgt_device->dev_alloc_list, &fs_info->fs_devices->alloc_list);

	fs_info->fs_devices->rw_devices++;



	btrfs_dev_replace_unlock(dev_replace, 1);

	btrfs_dev_replace_write_unlock(dev_replace);



	btrfs_rm_dev_replace_blocked(fs_info);
@@ -684,7 +684,7 @@ void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 
{

	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;



	btrfs_dev_replace_lock(dev_replace, 0);

	btrfs_dev_replace_read_lock(dev_replace);

	/* even if !dev_replace_is_valid, the values are good enough for

	 * the replace_status ioctl */

	args->result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NO_ERROR;
@@ -696,7 +696,7 @@ void btrfs_dev_replace_status(struct btrfs_fs_info *fs_info, 
	args->status.num_uncorrectable_read_errors =

		atomic64_read(&dev_replace->num_uncorrectable_read_errors);

	args->status.progress_1000 = btrfs_dev_replace_progress(fs_info);

	btrfs_dev_replace_unlock(dev_replace, 0);

	btrfs_dev_replace_read_unlock(dev_replace);

}



int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info)
@@ -713,13 +713,13 @@ int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 
		return -EROFS;



	mutex_lock(&dev_replace->lock_finishing_cancel_unmount);

	btrfs_dev_replace_lock(dev_replace, 1);

	btrfs_dev_replace_write_lock(dev_replace);

	switch (dev_replace->replace_state) {

	case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:

	case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:

	case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:

		result = BTRFS_IOCTL_DEV_REPLACE_RESULT_NOT_STARTED;

		btrfs_dev_replace_unlock(dev_replace, 1);

		btrfs_dev_replace_write_unlock(dev_replace);

		goto leave;

	case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:

	case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
@@ -733,7 +733,7 @@ int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info) 
	dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED;

	dev_replace->time_stopped = get_seconds();

	dev_replace->item_needs_writeback = 1;

	btrfs_dev_replace_unlock(dev_replace, 1);

	btrfs_dev_replace_write_unlock(dev_replace);

	btrfs_scrub_cancel(fs_info);



	trans = btrfs_start_transaction(root, 0);
@@ -762,7 +762,7 @@ void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 
	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;



	mutex_lock(&dev_replace->lock_finishing_cancel_unmount);

	btrfs_dev_replace_lock(dev_replace, 1);

	btrfs_dev_replace_write_lock(dev_replace);

	switch (dev_replace->replace_state) {

	case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:

	case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:
@@ -778,7 +778,7 @@ void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info) 
		break;

	}



	btrfs_dev_replace_unlock(dev_replace, 1);

	btrfs_dev_replace_write_unlock(dev_replace);

	mutex_unlock(&dev_replace->lock_finishing_cancel_unmount);

}
@@ -788,12 +788,12 @@ int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 
	struct task_struct *task;

	struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;



	btrfs_dev_replace_lock(dev_replace, 1);

	btrfs_dev_replace_write_lock(dev_replace);

	switch (dev_replace->replace_state) {

	case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED:

	case BTRFS_IOCTL_DEV_REPLACE_STATE_FINISHED:

	case BTRFS_IOCTL_DEV_REPLACE_STATE_CANCELED:

		btrfs_dev_replace_unlock(dev_replace, 1);

		btrfs_dev_replace_write_unlock(dev_replace);

		return 0;

	case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:

		break;
@@ -807,10 +807,10 @@ int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info) 
			   "cannot continue dev_replace, tgtdev is missing");

		btrfs_info(fs_info,

			   "you may cancel the operation after 'mount -o degraded'");

		btrfs_dev_replace_unlock(dev_replace, 1);

		btrfs_dev_replace_write_unlock(dev_replace);

		return 0;

	}

	btrfs_dev_replace_unlock(dev_replace, 1);

	btrfs_dev_replace_write_unlock(dev_replace);



	WARN_ON(test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));

	task = kthread_run(btrfs_dev_replace_kthread, fs_info, "btrfs-devrepl");
@@ -879,10 +879,21 @@ int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace) 
	return 1;

}



void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace, int rw)

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);

}



void btrfs_dev_replace_write_lock(struct btrfs_dev_replace *dev_replace)

{

	if (rw == 1) {

		/* write */

again:

	wait_event(dev_replace->read_lock_wq,

		   atomic_read(&dev_replace->blocking_readers) == 0);
@@ -891,23 +902,12 @@ again: 
		write_unlock(&dev_replace->lock);

		goto again;

	}

	} else {

		read_lock(&dev_replace->lock);

		atomic_inc(&dev_replace->read_locks);

	}

}



void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace, int rw)

void btrfs_dev_replace_write_unlock(struct btrfs_dev_replace *dev_replace)

{

	if (rw == 1) {

		/* write */

	ASSERT(atomic_read(&dev_replace->blocking_readers) == 0);

	write_unlock(&dev_replace->lock);

	} else {

		ASSERT(atomic_read(&dev_replace->read_locks) > 0);

		atomic_dec(&dev_replace->read_locks);

		read_unlock(&dev_replace->lock);

	}

}



/* inc blocking cnt and release read lock */

fs/btrfs/dev-replace.h

+4 −2
Original line number Diff line number Diff line
@@ -36,8 +36,10 @@ int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info); 
void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info);

int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info);

int btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace);

void btrfs_dev_replace_lock(struct btrfs_dev_replace *dev_replace, int rw);

void btrfs_dev_replace_unlock(struct btrfs_dev_replace *dev_replace, int rw);

void btrfs_dev_replace_read_lock(struct btrfs_dev_replace *dev_replace);

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);

fs/btrfs/reada.c

+5 −5
Original line number Diff line number Diff line
@@ -395,20 +395,20 @@ static struct reada_extent *reada_find_extent(struct btrfs_fs_info *fs_info, 
		goto error;



	/* insert extent in reada_tree + all per-device trees, all or nothing */

	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);

	btrfs_dev_replace_read_lock(&fs_info->dev_replace);

	spin_lock(&fs_info->reada_lock);

	ret = radix_tree_insert(&fs_info->reada_tree, index, re);

	if (ret == -EEXIST) {

		re_exist = radix_tree_lookup(&fs_info->reada_tree, index);

		re_exist->refcnt++;

		spin_unlock(&fs_info->reada_lock);

		btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);

		btrfs_dev_replace_read_unlock(&fs_info->dev_replace);

		radix_tree_preload_end();

		goto error;

	}

	if (ret) {

		spin_unlock(&fs_info->reada_lock);

		btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);

		btrfs_dev_replace_read_unlock(&fs_info->dev_replace);

		radix_tree_preload_end();

		goto error;

	}
@@ -451,13 +451,13 @@ static struct reada_extent *reada_find_extent(struct btrfs_fs_info *fs_info, 
			}

			radix_tree_delete(&fs_info->reada_tree, index);

			spin_unlock(&fs_info->reada_lock);

			btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);

			btrfs_dev_replace_read_unlock(&fs_info->dev_replace);

			goto error;

		}

		have_zone = 1;

	}

	spin_unlock(&fs_info->reada_lock);

	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);

	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);



	if (!have_zone)

		goto error;

fs/btrfs/scrub.c

+7 −7
Original line number Diff line number Diff line
@@ -3935,11 +3935,11 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx, 
			break;

		}



		btrfs_dev_replace_lock(&fs_info->dev_replace, 1);

		btrfs_dev_replace_write_lock(&fs_info->dev_replace);

		dev_replace->cursor_right = found_key.offset + length;

		dev_replace->cursor_left = found_key.offset;

		dev_replace->item_needs_writeback = 1;

		btrfs_dev_replace_unlock(&fs_info->dev_replace, 1);

		btrfs_dev_replace_write_unlock(&fs_info->dev_replace);

		ret = scrub_chunk(sctx, scrub_dev, chunk_offset, length,

				  found_key.offset, cache, is_dev_replace);
@@ -3975,10 +3975,10 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx, 


		scrub_pause_off(fs_info);



		btrfs_dev_replace_lock(&fs_info->dev_replace, 1);

		btrfs_dev_replace_write_lock(&fs_info->dev_replace);

		dev_replace->cursor_left = dev_replace->cursor_right;

		dev_replace->item_needs_writeback = 1;

		btrfs_dev_replace_unlock(&fs_info->dev_replace, 1);

		btrfs_dev_replace_write_unlock(&fs_info->dev_replace);



		if (ro_set)

			btrfs_dec_block_group_ro(cache);
@@ -4194,16 +4194,16 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start, 
		return -EIO;

	}



	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);

	btrfs_dev_replace_read_lock(&fs_info->dev_replace);

	if (dev->scrub_ctx ||

	    (!is_dev_replace &&

	     btrfs_dev_replace_is_ongoing(&fs_info->dev_replace))) {

		btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);

		btrfs_dev_replace_read_unlock(&fs_info->dev_replace);

		mutex_unlock(&fs_info->scrub_lock);

		mutex_unlock(&fs_info->fs_devices->device_list_mutex);

		return -EINPROGRESS;

	}

	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);

	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);



	ret = scrub_workers_get(fs_info, is_dev_replace);

	if (ret) {

fs/btrfs/volumes.c

+9 −9
Original line number Diff line number Diff line
@@ -1936,12 +1936,12 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path, 
	mutex_lock(&uuid_mutex);



	num_devices = fs_info->fs_devices->num_devices;

	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);

	btrfs_dev_replace_read_lock(&fs_info->dev_replace);

	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {

		WARN_ON(num_devices < 1);

		num_devices--;

	}

	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);

	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);



	ret = btrfs_check_raid_min_devices(fs_info, num_devices - 1);

	if (ret)
@@ -3910,12 +3910,12 @@ int btrfs_balance(struct btrfs_balance_control *bctl, 
	}



	num_devices = fs_info->fs_devices->num_devices;

	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);

	btrfs_dev_replace_read_lock(&fs_info->dev_replace);

	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {

		BUG_ON(num_devices < 1);

		num_devices--;

	}

	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);

	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);

	allowed = BTRFS_AVAIL_ALLOC_BIT_SINGLE | BTRFS_BLOCK_GROUP_DUP;

	if (num_devices > 1)

		allowed |= (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1);
@@ -5241,11 +5241,11 @@ int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len) 
		ret = 1;

	free_extent_map(em);



	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);

	btrfs_dev_replace_read_lock(&fs_info->dev_replace);

	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace) &&

	    fs_info->dev_replace.tgtdev)

		ret++;

	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);

	btrfs_dev_replace_read_unlock(&fs_info->dev_replace);



	return ret;

}
@@ -5823,10 +5823,10 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info, 
	if (!bbio_ret)

		goto out;



	btrfs_dev_replace_lock(dev_replace, 0);

	btrfs_dev_replace_read_lock(dev_replace);

	dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);

	if (!dev_replace_is_ongoing)

		btrfs_dev_replace_unlock(dev_replace, 0);

		btrfs_dev_replace_read_unlock(dev_replace);

	else

		btrfs_dev_replace_set_lock_blocking(dev_replace);
@@ -6024,7 +6024,7 @@ 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);

		btrfs_dev_replace_unlock(dev_replace, 0);

		btrfs_dev_replace_read_unlock(dev_replace);

	}

	free_extent_map(em);

	return ret;

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