btrfs-progs: error if device for mkfs is too small

Eric pointed out that mkfs abort if specified volume is too small:

  # truncate --size=2m testfile
  # ./mkfs.btrfs testfile
   :
  SMALL VOLUME: forcing mixed metadata/data groups
  mkfs.btrfs: volumes.c:852: btrfs_alloc_chunk: Assertion `!(ret)' failed.
  Aborted (core dumped)

As the first step to fix problems around there, let mkfs to report
error if the size of target volume is less than the size of the first
system block group, BTRFS_MKFS_SYSTEM_GROUP_SIZE (= 4MB).

Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This commit is contained in:
Hidetoshi Seto 2013-09-05 15:53:34 +09:00 committed by Chris Mason
parent 7c9074422a
commit f9d102efdc
1 changed files with 5 additions and 0 deletions

5
mkfs.c
View File

@ -1513,6 +1513,11 @@ int main(int ac, char **av)
dev_block_count = block_count;
}
/* To create the first block group and chunk 0 in make_btrfs */
if (dev_block_count < BTRFS_MKFS_SYSTEM_GROUP_SIZE) {
fprintf(stderr, "device is too small to make filesystem\n");
exit(1);
}
blocks[0] = BTRFS_SUPER_INFO_OFFSET;
for (i = 1; i < 7; i++) {