btrfs-progs: test/common: Enhance prepare_test_dev to reset device size

[platform/upstream/btrfs-progs.git] / cmds-filesystem.c

diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index c39f2d1..7728430 100644 (file)
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -150,7 +150,7 @@ static int cmd_filesystem_df(int argc, char **argv)
        return !!ret;
 }
 
-static int match_search_item_kernel(__u8 *fsid, char *mnt, char *label,
+static int match_search_item_kernel(u8 *fsid, char *mnt, char *label,
                                        char *search)
 {
        char uuidbuf[BTRFS_UUID_UNPARSED_SIZE];
@@ -431,33 +431,6 @@ out:
        return !found;
 }
 
-static int dev_to_fsid(const char *dev, __u8 *fsid)
-{
-       struct btrfs_super_block *disk_super;
-       char buf[BTRFS_SUPER_INFO_SIZE];
-       int ret;
-       int fd;
-
-       fd = open(dev, O_RDONLY);
-       if (fd < 0) {
-               ret = -errno;
-               return ret;
-       }
-
-       disk_super = (struct btrfs_super_block *)buf;
-       ret = btrfs_read_dev_super(fd, disk_super,
-                                  BTRFS_SUPER_INFO_OFFSET, SBREAD_DEFAULT);
-       if (ret)
-               goto out;
-
-       memcpy(fsid, disk_super->fsid, BTRFS_FSID_SIZE);
-       ret = 0;
-
-out:
-       close(fd);
-       return ret;
-}
-
 static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
 {
        struct btrfs_fs_devices *cur_seed, *next_seed;
@@ -705,7 +678,7 @@ static int cmd_filesystem_show(int argc, char **argv)
        int type = 0;
        char mp[PATH_MAX];
        char path[PATH_MAX];
-       __u8 fsid[BTRFS_FSID_SIZE];
+       u8 fsid[BTRFS_FSID_SIZE];
        char uuid_buf[BTRFS_UUID_UNPARSED_SIZE];
        unsigned unit_mode;
        int found = 0;
@@ -893,6 +866,11 @@ static const char * const cmd_filesystem_defrag_usage[] = {
        "-s start            defragment only from byte onward",
        "-l len              defragment only up to len bytes",
        "-t size             target extent size hint (default: 32M)",
+       "",
+       "Warning: most Linux kernels will break up the ref-links of COW data",
+       "(e.g., files copied with 'cp --reflink', snapshots) which may cause",
+       "considerable increase of space usage. See btrfs-filesystem(8) for",
+       "more information.",
        NULL
 };