btrfs-progs: create helper function to use lblkid to scan for btrfs disks

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This commit is contained in:
Anand Jain 2013-09-27 23:45:00 +08:00 committed by Chris Mason
parent 23c47a132f
commit 844034adba
2 changed files with 57 additions and 0 deletions

55
utils.c
View File

@ -1914,6 +1914,58 @@ int test_dev_for_mkfs(char *file, int force_overwrite, char *estr)
return 0;
}
int test_skip_this_disk(char *path)
{
int fd;
/*
* this will eliminate disks which are mounted (btrfs)
* and non-dm disk path when dm is enabled
*/
fd = open(path, O_RDWR|O_EXCL);
if (fd < 0)
return 1;
close(fd);
return 0;
}
int btrfs_scan_lblkid(int update_kernel)
{
int fd = -1;
u64 num_devices;
struct btrfs_fs_devices *tmp_devices;
blkid_dev_iterate iter = NULL;
blkid_dev dev = NULL;
blkid_cache cache = NULL;
char path[PATH_MAX];
if (blkid_get_cache(&cache, 0) < 0) {
printf("ERROR: lblkid cache get failed\n");
return 1;
}
blkid_probe_all(cache);
iter = blkid_dev_iterate_begin(cache);
blkid_dev_set_search(iter, "TYPE", "btrfs");
while (blkid_dev_next(iter, &dev) == 0) {
dev = blkid_verify(cache, dev);
if (!dev)
continue;
/* if we are here its definitly a btrfs disk*/
strcpy(path, blkid_dev_devname(dev));
if (test_skip_this_disk(path))
continue;
fd = open(path, O_RDONLY);
btrfs_scan_one_device(fd, path, &tmp_devices,
&num_devices, BTRFS_SUPER_INFO_OFFSET);
close(fd);
if (update_kernel)
btrfs_register_one_device(path);
}
blkid_dev_iterate_end(iter);
return 0;
}
/*
* scans devs for the btrfs
*/
@ -1928,6 +1980,9 @@ int scan_for_btrfs(int where, int update_kernel)
case BTRFS_SCAN_DEV:
ret = btrfs_scan_one_dir("/dev", update_kernel);
break;
case BTRFS_SCAN_LBLKID:
ret = btrfs_scan_lblkid(update_kernel);
break;
}
return ret;
}

View File

@ -27,6 +27,7 @@
#define BTRFS_SCAN_PROC 1
#define BTRFS_SCAN_DEV 2
#define BTRFS_SCAN_LBLKID (1ULL << 3)
int make_btrfs(int fd, const char *device, const char *label,
u64 blocks[6], u64 num_bytes, u32 nodesize,
@ -82,5 +83,6 @@ int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
int verify);
int ask_user(char *question);
int lookup_ino_rootid(int fd, u64 *rootid);
int btrfs_scan_lblkid(int update_kernel);
#endif