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: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2022-11-13 09:32:07 +08:00 committed by David Sterba
parent 3c32c7212f
commit cb3e217bdb
10 changed files with 36 additions and 39 deletions

View file

@ -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 @@ out:
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 @@ error:
"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;