ext4: support GETFSMAP ioctls
Support the GETFSMAP ioctls so that we can use the xfs free space
management tools to probe ext4 as well. Note that this is a partial
implementation -- we only report fixed-location metadata and free space;
everything else is reported as "unknown".
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index dbe51301..36de58a 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -5277,3 +5277,52 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
range->len = EXT4_C2B(EXT4_SB(sb), trimmed) << sb->s_blocksize_bits;
return ret;
}
+
+/* Iterate all the free extents in the group. */
+int
+ext4_mballoc_query_range(
+ struct super_block *sb,
+ ext4_group_t group,
+ ext4_grpblk_t start,
+ ext4_grpblk_t end,
+ ext4_mballoc_query_range_fn formatter,
+ void *priv)
+{
+ void *bitmap;
+ ext4_grpblk_t next;
+ struct ext4_buddy e4b;
+ int error;
+
+ error = ext4_mb_load_buddy(sb, group, &e4b);
+ if (error)
+ return error;
+ bitmap = e4b.bd_bitmap;
+
+ ext4_lock_group(sb, group);
+
+ start = (e4b.bd_info->bb_first_free > start) ?
+ e4b.bd_info->bb_first_free : start;
+ if (end >= EXT4_CLUSTERS_PER_GROUP(sb))
+ end = EXT4_CLUSTERS_PER_GROUP(sb) - 1;
+
+ while (start <= end) {
+ start = mb_find_next_zero_bit(bitmap, end + 1, start);
+ if (start > end)
+ break;
+ next = mb_find_next_bit(bitmap, end + 1, start);
+
+ ext4_unlock_group(sb, group);
+ error = formatter(sb, group, start, next - start, priv);
+ if (error)
+ goto out_unload;
+ ext4_lock_group(sb, group);
+
+ start = next + 1;
+ }
+
+ ext4_unlock_group(sb, group);
+out_unload:
+ ext4_mb_unload_buddy(&e4b);
+
+ return error;
+}
