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. 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
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