[PATCH 12/17] btrfs: remove struct btrfs_io_geometry

Christoph Hellwig
2022-09-01T07:44:16Z

Now that btrfs_get_io_geometry has a single caller, we can massage it
into a form that is more suitable for that caller and remove the
marshalling into and out of struct btrfs_io_geometry.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/btrfs/volumes.c | 115 +++++++++++++--------------------------------
fs/btrfs/volumes.h | 18 -------
2 files changed, 32 insertions(+), 101 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index dba8e53101ed9..e497b63238189 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6269,91 +6269,43 @@ static bool need_full_stripe(enum btrfs_map_op op)
return (op == BTRFS_MAP_WRITE || op == BTRFS_MAP_GET_READ_MIRRORS);
}

-/*
- * Calculate the geometry of a particular (address, len) tuple. This
- * information is used to calculate how big a particular bio can get before it
- * straddles a stripe.
- *
- * @fs_info: the filesystem
- * @em: mapping containing the logical extent
- * @op: type of operation - write or read
- * @logical: address that we want to figure out the geometry of
- * @io_geom: pointer used to return values
- *
- * Returns < 0 in case a chunk for the given logical address cannot be found,
- * usually shouldn't happen unless @logical is corrupted, 0 otherwise.
- */
-int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, struct extent_map *em,
- enum btrfs_map_op op, u64 logical,
- struct btrfs_io_geometry *io_geom)
+static u64 btrfs_max_io_len(struct map_lookup *map, enum btrfs_map_op op,
+ u64 offset, u64 *stripe_nr, u64 *stripe_offset,
+ u64 *full_stripe_start)
{
- struct map_lookup *map;
- u64 len;
- u64 offset;
- u64 stripe_offset;
- u64 stripe_nr;
- u32 stripe_len;
- u64 raid56_full_stripe_start = (u64)-1;
- int data_stripes;
+ u32 stripe_len = map->stripe_len;

ASSERT(op != BTRFS_MAP_DISCARD);

- map = em->map_lookup;
- /* Offset of this logical address in the chunk */
- offset = logical - em->start;
- /* Len of a stripe in a chunk */
- stripe_len = map->stripe_len;
/*
- * Stripe_nr is where this block falls in
- * stripe_offset is the offset of this block in its stripe.
+ * Stripe_nr is the stripe where this block falls.
+ * Stripe_offset is the offset of this block in its stripe.
*/
- stripe_nr = div64_u64_rem(offset, stripe_len, &stripe_offset);
- ASSERT(stripe_offset < U32_MAX);
+ *stripe_nr = div64_u64_rem(offset, stripe_len, stripe_offset);
+ ASSERT(*stripe_offset < U32_MAX);

- data_stripes = nr_data_stripes(map);
+ if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
+ unsigned long full_stripe_len =
+ stripe_len * nr_data_stripes(map);

- /* Only stripe based profiles needs to check against stripe length. */
- if (map->type & BTRFS_BLOCK_GROUP_STRIPE_MASK) {
- u64 max_len = stripe_len - stripe_offset;
+ *full_stripe_start =
+ div64_u64(offset, full_stripe_len) * full_stripe_len;

/*
- * In case of raid56, we need to know the stripe aligned start
+ * For writes to RAID[56], allow to write a full stripe set, but
+ * no straddling of stripe sets.
*/
- if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
- unsigned long full_stripe_len = stripe_len * data_stripes;
- raid56_full_stripe_start = offset;
-
- /*
- * Allow a write of a full stripe, but make sure we
- * don't allow straddling of stripes
- */
- raid56_full_stripe_start = div64_u64(raid56_full_stripe_start,
- full_stripe_len);
- raid56_full_stripe_start *= full_stripe_len;
-
- /*
- * For writes to RAID[56], allow a full stripeset across
- * all disks. For other RAID types and for RAID[56]
- * reads, just allow a single stripe (on a single disk).
- */
- if (op == BTRFS_MAP_WRITE) {
- max_len = stripe_len * data_stripes -
- (offset - raid56_full_stripe_start);
- }
- }
- len = min_t(u64, em->len - offset, max_len);
- } else {
- len = em->len - offset;
+ if (op == BTRFS_MAP_WRITE)
+ return full_stripe_len - (offset - *full_stripe_start);
}

- io_geom->len = len;
- io_geom->offset = offset;
- io_geom->stripe_len = stripe_len;
- io_geom->stripe_nr = stripe_nr;
- io_geom->stripe_offset = stripe_offset;
- io_geom->raid56_stripe_offset = raid56_full_stripe_start;
-
- return 0;
+ /*
+ * For other RAID types and for RAID[56] reads, just allow a single
+ * stripe (on a single disk).
+ */
+ if (map->type & BTRFS_BLOCK_GROUP_STRIPE_MASK)
+ return stripe_len - *stripe_offset;
+ return U64_MAX;
}

static void set_io_stripe(struct btrfs_io_stripe *dst, const struct map_lookup *map,
@@ -6372,6 +6324,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
{
struct extent_map *em;
struct map_lookup *map;
+ u64 map_offset;
u64 stripe_offset;
u64 stripe_nr;
u64 stripe_len;
@@ -6390,7 +6343,7 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
int patch_the_first_stripe_for_dev_replace = 0;
u64 physical_to_patch_in_first_stripe = 0;
u64 raid56_full_stripe_start = (u64)-1;
- struct btrfs_io_geometry geom;
+ u64 max_len;

ASSERT(bioc_ret);
ASSERT(op != BTRFS_MAP_DISCARD);
@@ -6398,18 +6351,14 @@ static int __btrfs_map_block(struct btrfs_fs_info *fs_info,
em = btrfs_get_chunk_map(fs_info, logical, *length);
ASSERT(!IS_ERR(em));

- ret = btrfs_get_io_geometry(fs_info, em, op, logical, &geom);
- if (ret < 0)
- return ret;
-
map = em->map_lookup;
-
- *length = geom.len;
- stripe_len = geom.stripe_len;
- stripe_nr = geom.stripe_nr;
- stripe_offset = geom.stripe_offset;
- raid56_full_stripe_start = geom.raid56_stripe_offset;
data_stripes = nr_data_stripes(map);
+ stripe_len = map->stripe_len;
+
+ map_offset = logical - em->start;
+ max_len = btrfs_max_io_len(map, op, map_offset, &stripe_nr,
+ &stripe_offset, &raid56_full_stripe_start);
+ *length = min_t(u64, em->len - map_offset, max_len);

down_read(&dev_replace->rwsem);
dev_replace_is_ongoing = btrfs_dev_replace_is_ongoing(dev_replace);
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 82bbc0aa7081d..3b1fe04ff078e 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -51,21 +51,6 @@ enum btrfs_raid_types {
BTRFS_NR_RAID_TYPES
};

-struct btrfs_io_geometry {
- /* remaining bytes before crossing a stripe */
- u64 len;
- /* offset of logical address in chunk */
- u64 offset;
- /* length of single IO stripe */
- u32 stripe_len;
- /* offset of address in stripe */
- u32 stripe_offset;
- /* number of stripe where address falls */
- u64 stripe_nr;
- /* offset of raid56 stripe into the chunk */
- u64 raid56_stripe_offset;
-};
-
/*
* Use sequence counter to get consistent device stat data on
* 32-bit processors.
@@ -568,9 +553,6 @@ int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
struct btrfs_discard_stripe *btrfs_map_discard(struct btrfs_fs_info *fs_info,
u64 logical, u64 *length_ret,
u32 *num_stripes);
-int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, struct extent_map *map,
- enum btrfs_map_op op, u64 logical,
- struct btrfs_io_geometry *io_geom);
int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
struct btrfs_block_group *btrfs_create_chunk(struct btrfs_trans_handle *trans,
--
2.30.2