From cb3e217bdb39e390f8e64af519acb02af336b53d Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Sun, 13 Nov 2022 09:32:07 +0800 Subject: 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 (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 "". [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 (devid 2) to /dev/mapper/test-scratch2 started BTRFS error (device dm-1): failed to rebuild valid logical 38862848 for dev Reviewed-by: Anand Jain Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- fs/btrfs/ioctl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/ioctl.c') diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 7a9e697d9931..bed74a3ff574 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1228,7 +1228,7 @@ static noinline int btrfs_ioctl_resize(struct file *file, if (ret == 0 && new_size != old_size) btrfs_info_in_rcu(fs_info, "resize device %s (devid %llu) from %llu to %llu", - rcu_str_deref(device->name), device->devid, + btrfs_dev_name(device), device->devid, old_size, new_size); out_finish: btrfs_exclop_finish(fs_info); @@ -2860,7 +2860,7 @@ static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info, di_args->total_bytes = btrfs_device_get_total_bytes(dev); memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid)); if (dev->name) { - strncpy(di_args->path, rcu_str_deref(dev->name), + strncpy(di_args->path, btrfs_dev_name(dev), sizeof(di_args->path) - 1); di_args->path[sizeof(di_args->path) - 1] = 0; } else { -- cgit v1.2.3