On Fri, Jun 17, 2016 at 11:07:54AM +0530, Chandan Rajendra wrote: > stripesize should ideally be set to the value of sectorsize. However > previous versions of btrfs-progs/mkfs.btrfs had set stripesize to a > value of 4096. On machines with PAGE_SIZE other than 4096, This could > lead to the following scenario, > > - /dev/loop0, /dev/loop1 and /dev/loop2 are mounted as a single > filesystem. The filesystem was created by an older version of mkfs.btrfs > which set stripesize to 4k. > - losetup -a > /dev/loop0: [0030]:19477 (/root/disk-imgs/file-0.img) > /dev/loop1: [0030]:16577 (/root/disk-imgs/file-1.img) > /dev/loop2: [64770]:3423229 (/root/disk-imgs/file-2.img) > - /etc/mtab lists only /dev/loop0 > - losetup /dev/loop4 /root/disk-imgs/file-1.img > The new mkfs.btrfs invoked as 'mkfs.btrfs -f /dev/loop4' succeeds even > though /dev/loop1 has already been mounted and has > /root/disk-imgs/file-1.img as its backing file. > > The above behaviour occurs because check_super() function returns an > error code (due to stripesize not being set to 4096) and hence > check_mounted_where() function treats /dev/loop1 as a disk containing a > filesystem other than Btrfs. > > Hence as a workaround this commit allows 4096 as a valid stripesize. > > Signed-off-by: Chandan Rajendra <chandan@xxxxxxxxxxxxxxxxxx> Applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
