btrfs-progs: Check sb_bytenr with device size before scanning one device.

When using btrfs check with -s option, if using '-s 2' on a small
device which doesn't have the third superblock, "No valid Btrfs found"
will be output, but it is not appropriate.

So check sb_bytenr against device size before scanning a device and
output proper error message.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
This commit is contained in:
Qu Wenruo 2014-11-12 13:52:11 +08:00 committed by David Sterba
parent 1e3da6d65e
commit 0c44c195fe

View File

@ -1008,10 +1008,20 @@ int btrfs_scan_fs_devices(int fd, const char *path,
u64 sb_bytenr, int super_recover)
{
u64 total_devs;
u64 dev_size;
int ret;
if (!sb_bytenr)
sb_bytenr = BTRFS_SUPER_INFO_OFFSET;
dev_size = lseek(fd, 0, SEEK_END);
if (dev_size < 0)
return (int)(dev_size);
lseek(fd, 0, SEEK_SET);
if (sb_bytenr > dev_size) {
fprintf(stderr, "Superblock bytenr is larger than device size\n");
return -EINVAL;
}
ret = btrfs_scan_one_device(fd, path, fs_devices,
&total_devs, sb_bytenr, super_recover);
if (ret) {