diff options
authorChandan Rajendra <chandan@linux.vnet.ibm.com>2016-06-17 11:07:54 +0530
committerDavid Sterba <dsterba@suse.com>2016-06-17 17:11:26 +0200
commit49ec1413a78624d4bf4c99d184c8fbaf99cd0ad4 (patch)
parentdf05c7ed455f519e6e15e46196392e4757257305 (diff)
Btrfs-progs: Initialize stripesize to the value of sectorsize
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@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2 files changed, 3 insertions, 1 deletions
diff --git a/disk-io.c b/disk-io.c
index 77eb0a6..fbce506 100644
--- a/disk-io.c
+++ b/disk-io.c
@@ -1476,7 +1476,8 @@ static int check_super(struct btrfs_super_block *sb)
error("invalid bytes_used %llu", btrfs_super_bytes_used(sb));
goto error_out;
- if (btrfs_super_stripesize(sb) != 4096) {
+ if ((btrfs_super_stripesize(sb) != 4096)
+ && (btrfs_super_stripesize(sb) != btrfs_super_sectorsize(sb))) {
error("invalid stripesize %u", btrfs_super_stripesize(sb));
goto error_out;
diff --git a/mkfs.c b/mkfs.c
index a3a3c14..697bdc2 100644
--- a/mkfs.c
+++ b/mkfs.c
@@ -1482,6 +1482,7 @@ int main(int argc, char **argv)
sectorsize = max(sectorsize, (u32)sysconf(_SC_PAGESIZE));
+ stripesize = sectorsize;
saved_optind = optind;
dev_cnt = argc - optind;
if (dev_cnt == 0)