[v2,2/6] btrfs: Do chunk level rw degrade check at mount time
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Message ID 20170306085855.11403-3-quwenruo@cn.fujitsu.com
State New
Headers show

Commit Message

Qu Wenruo March 6, 2017, 8:58 a.m. UTC
Now use the btrfs_check_rw_degradable() to do mount time degration check.

With this patch, now we can mount with the following case:
 # mkfs.btrfs -f -m raid1 -d single /dev/sdb /dev/sdc
 # wipefs -a /dev/sdc
 # mount /dev/sdb /mnt/btrfs -o degraded
 As the single data chunk is only in sdb, so it's OK to mount as
 degraded, as missing one device is OK for RAID1.

But still fail with the following case as expected:
 # mkfs.btrfs -f -m raid1 -d single /dev/sdb /dev/sdc
 # wipefs -a /dev/sdb
 # mount /dev/sdc /mnt/btrfs -o degraded
 As the data chunk is only in sdb, so it's not OK to mount it as

Reported-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Reported-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
 fs/btrfs/disk-io.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

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diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 73fdc6bdaea9..c26b8a0b121c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3057,15 +3057,10 @@  int open_ctree(struct super_block *sb,
 		btrfs_err(fs_info, "failed to read block groups: %d", ret);
 		goto fail_sysfs;
-	fs_info->num_tolerated_disk_barrier_failures =
-		btrfs_calc_num_tolerated_disk_barrier_failures(fs_info);
-	if (fs_info->fs_devices->missing_devices >
-	     fs_info->num_tolerated_disk_barrier_failures &&
-	    !(sb->s_flags & MS_RDONLY)) {
+	if (!(sb->s_flags & MS_RDONLY) && !btrfs_check_rw_degradable(fs_info)) {
-"missing devices (%llu) exceeds the limit (%d), writeable mount is not allowed",
-			fs_info->fs_devices->missing_devices,
-			fs_info->num_tolerated_disk_barrier_failures);
+		"writeable mount is not allowed due to too many missing devices");
 		goto fail_sysfs;