btrfs: extend btrfs_rmap_block for specifying a device

btrfs_rmap_block currently reverse-maps the physical addresses on all
devices to the corresponding logical addresses.

Extend the function to match to a specified device. The old functionality
of querying all devices is left intact by specifying NULL as target
device.

A block_device instead of a btrfs_device is passed into btrfs_rmap_block,
as this function is intended to reverse-map the result of a bio, which
only has a block_device.

Also export the function for later use.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index 70a0c0f..f5e9f56 100644 (file)
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -1588,6 +1588,7 @@ static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
  *
  * @fs_info:       the filesystem
  * @chunk_start:   logical address of block group
+ * @bdev:         physical device to resolve, can be NULL to indicate any device
  * @physical:     physical address to map to logical addresses
  * @logical:      return array of logical addresses which map to @physical
  * @naddrs:       length of @logical
@@ -1597,9 +1598,9 @@ static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
  * Used primarily to exclude those portions of a block group that contain super
  * block copies.
  */
-EXPORT_FOR_TESTS
 int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
-                    u64 physical, u64 **logical, int *naddrs, int *stripe_len)
+                    struct block_device *bdev, u64 physical, u64 **logical,
+                    int *naddrs, int *stripe_len)
 {
        struct extent_map *em;
        struct map_lookup *map;
@@ -1617,6 +1618,7 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
        map = em->map_lookup;
        data_stripe_length = em->orig_block_len;
        io_stripe_size = map->stripe_len;
+       chunk_start = em->start;
 
        /* For RAID5/6 adjust to a full IO stripe length */
        if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
@@ -1631,14 +1633,18 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
        for (i = 0; i < map->num_stripes; i++) {
                bool already_inserted = false;
                u64 stripe_nr;
+               u64 offset;
                int j;
 
                if (!in_range(physical, map->stripes[i].physical,
                              data_stripe_length))
                        continue;
 
+               if (bdev && map->stripes[i].dev->bdev != bdev)
+                       continue;
+
                stripe_nr = physical - map->stripes[i].physical;
-               stripe_nr = div64_u64(stripe_nr, map->stripe_len);
+               stripe_nr = div64_u64_rem(stripe_nr, map->stripe_len, &offset);
 
                if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
                        stripe_nr = stripe_nr * map->num_stripes + i;
@@ -1652,7 +1658,7 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
                 * instead of map->stripe_len
                 */
 
-               bytenr = chunk_start + stripe_nr * io_stripe_size;
+               bytenr = chunk_start + stripe_nr * io_stripe_size + offset;
 
                /* Ensure we don't add duplicate addresses */
                for (j = 0; j < nr; j++) {
@@ -1694,7 +1700,7 @@ static int exclude_super_stripes(struct btrfs_block_group *cache)
 
        for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) {
                bytenr = btrfs_sb_offset(i);
-               ret = btrfs_rmap_block(fs_info, cache->start,
+               ret = btrfs_rmap_block(fs_info, cache->start, NULL,
                                       bytenr, &logical, &nr, &stripe_len);
                if (ret)
                        return ret;

diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 0fd66fe..d14ac03 100644 (file)
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -277,6 +277,9 @@ void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
 int btrfs_free_block_groups(struct btrfs_fs_info *info);
 void btrfs_wait_space_cache_v1_finished(struct btrfs_block_group *cache,
                                struct btrfs_caching_control *caching_ctl);
+int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
+                      struct block_device *bdev, u64 physical, u64 **logical,
+                      int *naddrs, int *stripe_len);
 
 static inline u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info)
 {
@@ -303,9 +306,4 @@ static inline int btrfs_block_group_done(struct btrfs_block_group *cache)
 void btrfs_freeze_block_group(struct btrfs_block_group *cache);
 void btrfs_unfreeze_block_group(struct btrfs_block_group *cache);
 
-#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
-int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
-                    u64 physical, u64 **logical, int *naddrs, int *stripe_len);
-#endif
-
 #endif /* BTRFS_BLOCK_GROUP_H */

diff --git a/fs/btrfs/tests/extent-map-tests.c b/fs/btrfs/tests/extent-map-tests.c
index 57379e9..c0aefe6 100644 (file)
--- a/fs/btrfs/tests/extent-map-tests.c
+++ b/fs/btrfs/tests/extent-map-tests.c
@@ -507,7 +507,7 @@ static int test_rmap_block(struct btrfs_fs_info *fs_info,
                goto out_free;
        }
 
-       ret = btrfs_rmap_block(fs_info, em->start, btrfs_sb_offset(1),
+       ret = btrfs_rmap_block(fs_info, em->start, NULL, btrfs_sb_offset(1),
                               &logical, &out_ndaddrs, &out_stripe_len);
        if (ret || (out_ndaddrs == 0 && test->expected_mapped_addr)) {
                test_err("didn't rmap anything but expected %d",