Commit cb3e217b authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: use btrfs_dev_name() helper to handle missing devices better 



[BUG]
If dev-replace failed to re-construct its data/metadata, the kernel
message would be incorrect for the missing device:

 BTRFS info (device dm-1): dev_replace from <missing disk> (devid 2) to /dev/mapper/test-scratch2 started
 BTRFS error (device dm-1): failed to rebuild valid logical 38862848 for dev (efault)

Note the above "dev (efault)" of the second line.
While the first line is properly reporting "<missing disk>".

[CAUSE]
Although dev-replace is using btrfs_dev_name(), the heavy lifting work
is still done by scrub (scrub is reused by both dev-replace and regular
scrub).

Unfortunately scrub code never uses btrfs_dev_name() helper, as it's
only declared locally inside dev-replace.c.

[FIX]
Fix the output by:

- Move the btrfs_dev_name() helper to volumes.h

- Use btrfs_dev_name() to replace open-coded rcu_str_deref() calls
  Only zoned code is not touched, as I'm not familiar with degraded
  zoned code.

- Constify return value and parameter

Now the output looks pretty sane:

 BTRFS info (device dm-1): dev_replace from <missing disk> (devid 2) to /dev/mapper/test-scratch2 started
 BTRFS error (device dm-1): failed to rebuild valid logical 38862848 for dev <missing disk>

Reviewed-by: default avatarAnand Jain <anand.jain@oracle.com>
Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 3c32c721

fs/btrfs/check-integrity.c

+1 −1
Original line number Diff line number Diff line
@@ -757,7 +757,7 @@ static int btrfsic_process_superblock_dev_mirror( 
			btrfs_info_in_rcu(fs_info,

			"new initial S-block (bdev %p, %s) @%llu (%pg/%llu/%d)",

				     superblock_bdev,

				     rcu_str_deref(device->name), dev_bytenr,

				     btrfs_dev_name(device), dev_bytenr,

				     dev_state->bdev, dev_bytenr,

				     superblock_mirror_num);

		list_add(&superblock_tmp->all_blocks_node,

fs/btrfs/dev-replace.c

+3 −12
Original line number Diff line number Diff line
@@ -18,7 +18,6 @@ 
#include "volumes.h"

#include "async-thread.h"

#include "check-integrity.h"

#include "rcu-string.h"

#include "dev-replace.h"

#include "sysfs.h"

#include "zoned.h"
@@ -451,14 +450,6 @@ int btrfs_run_dev_replace(struct btrfs_trans_handle *trans) 
	return ret;

}



static char* btrfs_dev_name(struct btrfs_device *device)

{

	if (!device || test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state))

		return "<missing disk>";

	else

		return rcu_str_deref(device->name);

}



static int mark_block_group_to_copy(struct btrfs_fs_info *fs_info,

				    struct btrfs_device *src_dev)

{
@@ -674,7 +665,7 @@ static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, 
		      "dev_replace from %s (devid %llu) to %s started",

		      btrfs_dev_name(src_device),

		      src_device->devid,

		      rcu_str_deref(tgt_device->name));

		      btrfs_dev_name(tgt_device));



	/*

	 * from now on, the writes to the srcdev are all duplicated to
@@ -933,7 +924,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 
				 "btrfs_scrub_dev(%s, %llu, %s) failed %d",

				 btrfs_dev_name(src_device),

				 src_device->devid,

				 rcu_str_deref(tgt_device->name), scrub_ret);

				 btrfs_dev_name(tgt_device), scrub_ret);

error:

		up_write(&dev_replace->rwsem);

		mutex_unlock(&fs_info->chunk_mutex);
@@ -951,7 +942,7 @@ static int btrfs_dev_replace_finishing(struct btrfs_fs_info *fs_info, 
			  "dev_replace from %s (devid %llu) to %s finished",

			  btrfs_dev_name(src_device),

			  src_device->devid,

			  rcu_str_deref(tgt_device->name));

			  btrfs_dev_name(tgt_device));

	clear_bit(BTRFS_DEV_STATE_REPLACE_TGT, &tgt_device->dev_state);

	tgt_device->devid = src_device->devid;

	src_device->devid = BTRFS_DEV_REPLACE_DEVID;

fs/btrfs/disk-io.c

+1 −1
Original line number Diff line number Diff line
@@ -3944,7 +3944,7 @@ static void btrfs_end_super_write(struct bio *bio) 
		if (bio->bi_status) {

			btrfs_warn_rl_in_rcu(device->fs_info,

				"lost page write due to IO error on %s (%d)",

				rcu_str_deref(device->name),

				btrfs_dev_name(device),

				blk_status_to_errno(bio->bi_status));

			ClearPageUptodate(page);

			SetPageError(page);

fs/btrfs/extent-tree.c

+1 −1
Original line number Diff line number Diff line
@@ -6048,7 +6048,7 @@ static int btrfs_trim_free_extents(struct btrfs_device *device, u64 *trimmed) 
			btrfs_warn_in_rcu(fs_info,

"ignoring attempt to trim beyond device size: offset %llu length %llu device %s device size %llu",

					  start, end - start + 1,

					  rcu_str_deref(device->name),

					  btrfs_dev_name(device),

					  device->total_bytes);

			mutex_unlock(&fs_info->chunk_mutex);

			ret = 0;

fs/btrfs/extent_io.c

+1 −2
Original line number Diff line number Diff line
@@ -611,8 +611,7 @@ static int repair_io_failure(struct btrfs_fs_info *fs_info, u64 ino, u64 start, 


	btrfs_info_rl_in_rcu(fs_info,

		"read error corrected: ino %llu off %llu (dev %s sector %llu)",

				  ino, start,

				  rcu_str_deref(dev->name), sector);

			     ino, start, btrfs_dev_name(dev), sector);

	ret = 0;



out_bio_uninit: