2014-05-16 22:44 GMT+08:00 Anand Jain <anand.j...@oracle.com>: > > > Wang, > > when we unmount && mount (instead of remount) and followed > with device del <seed> it ends up with null pointer deref at > btrfs_shrink_dev. Thats because the btrfs_root is not set for > seed disk as we mounted the writable sprout disk. I am writing > a separate fix for that as its a new bug.
You means this one which was addressed by Liu few days ago? https://patchwork.kernel.org/patch/4150471/ > > Thanks, Anand > > > > On 16/05/14 22:14, Anand Jain wrote: >> >> >> Wang, >> >> There seems to be a problem - after we delete the seed >> disk, the total_devices didn't decrement back to 1. >> reproducer as in the below test case. (I used btrfs-devlist >> (posted) to check fs_devices). >> >> > # mkfs.btrfs -f /dev/sdb >> > # btrfstune -S 1 /dev/sdb >> > # mount /dev/sdb /mnt >> > # btrfs device add -f /dev/sdc /mnt --->fs_devices->total_devices = 1 >> mount -o rw,remount /mnt >> btrfs dev del /dev/sdb /mnt --> fs_devices->total_devices is still 2 >> >> Thanks, Anand >> >> >> On 13/05/14 17:05, Wang Shilong wrote: >>> >>> Seeding device support allows us to create a new filesystem >>> based on existed filesystem. >>> >>> However newly created filesystem's @total_devices should include seed >>> devices. This patch fix the following problem: >>> >>> # mkfs.btrfs -f /dev/sdb >>> # btrfstune -S 1 /dev/sdb >>> # mount /dev/sdb /mnt >>> # btrfs device add -f /dev/sdc /mnt --->fs_devices->total_devices = 1 >>> # umount /mnt >>> # mount /dev/sdc /mnt --->fs_devices->total_devices = 2 >>> >>> This is because we record right @total_devices in superblock, but >>> @fs_devices->total_devices is reset to be 0 in btrfs_prepare_sprout(). >>> >>> Fix this problem by not resetting @fs_devices->total_devices. >>> >>> Signed-off-by: Wang Shilong <wangsl.f...@cn.fujitsu.com> >>> --- >>> fs/btrfs/volumes.c | 1 - >>> 1 file changed, 1 deletion(-) >>> >>> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c >>> index 6fd7fe6..19b2d32 100644 >>> --- a/fs/btrfs/volumes.c >>> +++ b/fs/btrfs/volumes.c >>> @@ -1883,7 +1883,6 @@ static int btrfs_prepare_sprout(struct >>> btrfs_root *root) >>> fs_devices->seeding = 0; >>> fs_devices->num_devices = 0; >>> fs_devices->open_devices = 0; >>> - fs_devices->total_devices = 0; >>> fs_devices->seed = seed_devices; >>> >>> generate_random_uuid(fs_devices->fsid); >>> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in >> the body of a message to majord...@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
