[PATCH 02/13] btrfs: re-introduce struct btrfs_io_geometry

Johannes Thumshirn
2023-12-12T12:38:33Z

Re-introduce struct btrfs_io_geometry, holding the necessary bits and
pieces needed in btrfs_map_block() to decide the I/O geometry of a specific
block mapping.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
fs/btrfs/volumes.c | 156 +++++++++++++++++++++++++++++------------------------
1 file changed, 86 insertions(+), 70 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 1011178a244c..d0e529b3fd39 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -41,6 +41,16 @@
BTRFS_BLOCK_GROUP_RAID10 | \
BTRFS_BLOCK_GROUP_RAID56_MASK)

+struct btrfs_io_geometry {
+ u32 stripe_index;
+ u32 stripe_nr;
+ int mirror_num;
+ int num_stripes;
+ u64 stripe_offset;
+ u64 raid56_full_stripe_start;
+ int max_errors;
+};
+
const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
[BTRFS_RAID_RAID10] = {
.sub_stripes = 2,
@@ -6393,28 +6403,22 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
struct btrfs_io_stripe *smap, int *mirror_num_ret)
{
struct btrfs_chunk_map *map;
+ struct btrfs_io_geometry io_geom = { };
u64 map_offset;
- u64 stripe_offset;
- u32 stripe_nr;
- u32 stripe_index;
int data_stripes;
int i;
int ret = 0;
- int mirror_num = (mirror_num_ret ? *mirror_num_ret : 0);
- int num_stripes;
int num_copies;
- int max_errors = 0;
struct btrfs_io_context *bioc = NULL;
struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
int dev_replace_is_ongoing = 0;
u16 num_alloc_stripes;
- u64 raid56_full_stripe_start = (u64)-1;
u64 max_len;

ASSERT(bioc_ret);

num_copies = btrfs_num_copies(fs_info, logical, fs_info->sectorsize);
- if (mirror_num > num_copies)
+ if (io_geom.mirror_num > num_copies)
return -EINVAL;

map = btrfs_get_chunk_map(fs_info, logical, *length);
@@ -6424,8 +6428,10 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
data_stripes = nr_data_stripes(map);

map_offset = logical - map->start;
- max_len = btrfs_max_io_len(map, op, map_offset, &stripe_nr,
- &stripe_offset, &raid56_full_stripe_start);
+ io_geom.raid56_full_stripe_start = (u64)-1;
+ max_len = btrfs_max_io_len(map, op, map_offset, &io_geom.stripe_nr,
+ &io_geom.stripe_offset,
+ &io_geom.raid56_full_stripe_start);
*length = min_t(u64, map->chunk_len - map_offset, max_len);

down_read(&dev_replace->rwsem);
@@ -6437,53 +6443,54 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
if (!dev_replace_is_ongoing)
up_read(&dev_replace->rwsem);

- num_stripes = 1;
- stripe_index = 0;
+ io_geom.num_stripes = 1;
+ io_geom.stripe_index = 0;
+ io_geom.mirror_num = (mirror_num_ret ? *mirror_num_ret : 0);
if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
- stripe_index = stripe_nr % map->num_stripes;
- stripe_nr /= map->num_stripes;
+ io_geom.stripe_index = io_geom.stripe_nr % map->num_stripes;
+ io_geom.stripe_nr /= map->num_stripes;
if (op == BTRFS_MAP_READ)
- mirror_num = 1;
+ io_geom.mirror_num = 1;
} else if (map->type & BTRFS_BLOCK_GROUP_RAID1_MASK) {
if (op != BTRFS_MAP_READ) {
- num_stripes = map->num_stripes;
- } else if (mirror_num) {
- stripe_index = mirror_num - 1;
+ io_geom.num_stripes = map->num_stripes;
+ } else if (io_geom.mirror_num) {
+ io_geom.stripe_index = io_geom.mirror_num - 1;
} else {
- stripe_index = find_live_mirror(fs_info, map, 0,
+ io_geom.stripe_index = find_live_mirror(fs_info, map, 0,
dev_replace_is_ongoing);
- mirror_num = stripe_index + 1;
+ io_geom.mirror_num = io_geom.stripe_index + 1;
}

} else if (map->type & BTRFS_BLOCK_GROUP_DUP) {
if (op != BTRFS_MAP_READ) {
- num_stripes = map->num_stripes;
- } else if (mirror_num) {
- stripe_index = mirror_num - 1;
+ io_geom.num_stripes = map->num_stripes;
+ } else if (io_geom.mirror_num) {
+ io_geom.stripe_index = io_geom.mirror_num - 1;
} else {
- mirror_num = 1;
+ io_geom.mirror_num = 1;
}

} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
u32 factor = map->num_stripes / map->sub_stripes;

- stripe_index = (stripe_nr % factor) * map->sub_stripes;
- stripe_nr /= factor;
+ io_geom.stripe_index = (io_geom.stripe_nr % factor) * map->sub_stripes;
+ io_geom.stripe_nr /= factor;

if (op != BTRFS_MAP_READ)
- num_stripes = map->sub_stripes;
- else if (mirror_num)
- stripe_index += mirror_num - 1;
+ io_geom.num_stripes = map->sub_stripes;
+ else if (io_geom.mirror_num)
+ io_geom.stripe_index += io_geom.mirror_num - 1;
else {
- int old_stripe_index = stripe_index;
- stripe_index = find_live_mirror(fs_info, map,
- stripe_index,
+ int old_stripe_index = io_geom.stripe_index;
+ io_geom.stripe_index = find_live_mirror(fs_info, map,
+ io_geom.stripe_index,
dev_replace_is_ongoing);
- mirror_num = stripe_index - old_stripe_index + 1;
+ io_geom.mirror_num = io_geom.stripe_index - old_stripe_index + 1;
}

} else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
- if (op != BTRFS_MAP_READ || mirror_num > 1) {
+ if (op != BTRFS_MAP_READ || io_geom.mirror_num > 1) {
/*
* Needs full stripe mapping.
*
@@ -6495,29 +6502,33 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
* but that can be expensive. Here we just divide
* @stripe_nr with @data_stripes.
*/
- stripe_nr /= data_stripes;
+ io_geom.stripe_nr /= data_stripes;

/* RAID[56] write or recovery. Return all stripes */
- num_stripes = map->num_stripes;
- max_errors = btrfs_chunk_max_errors(map);
+ io_geom.num_stripes = map->num_stripes;
+ io_geom.max_errors = btrfs_chunk_max_errors(map);

/* Return the length to the full stripe end */
*length = min(logical + *length,
- raid56_full_stripe_start + map->start +
- btrfs_stripe_nr_to_offset(data_stripes)) -
+ io_geom.raid56_full_stripe_start +
+ map->start +
+ btrfs_stripe_nr_to_offset(
+ data_stripes)) -
logical;
- stripe_index = 0;
- stripe_offset = 0;
+ io_geom.stripe_index = 0;
+ io_geom.stripe_offset = 0;
} else {
- ASSERT(mirror_num <= 1);
+ ASSERT(io_geom.mirror_num <= 1);
/* Just grab the data stripe directly. */
- stripe_index = stripe_nr % data_stripes;
- stripe_nr /= data_stripes;
+ io_geom.stripe_index = io_geom.stripe_nr % data_stripes;
+ io_geom.stripe_nr /= data_stripes;

/* We distribute the parity blocks across stripes */
- stripe_index = (stripe_nr + stripe_index) % map->num_stripes;
- if (op == BTRFS_MAP_READ && mirror_num < 1)
- mirror_num = 1;
+ io_geom.stripe_index =
+ (io_geom.stripe_nr + io_geom.stripe_index) %
+ map->num_stripes;
+ if (op == BTRFS_MAP_READ && io_geom.mirror_num < 1)
+ io_geom.mirror_num = 1;
}
} else {
/*
@@ -6525,19 +6536,19 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
* device we have to walk to find the data, and stripe_index is
* the number of our device in the stripe array
*/
- stripe_index = stripe_nr % map->num_stripes;
- stripe_nr /= map->num_stripes;
- mirror_num = stripe_index + 1;
+ io_geom.stripe_index = io_geom.stripe_nr % map->num_stripes;
+ io_geom.stripe_nr /= map->num_stripes;
+ io_geom.mirror_num = io_geom.stripe_index + 1;
}
- if (stripe_index >= map->num_stripes) {
+ if (io_geom.stripe_index >= map->num_stripes) {
btrfs_crit(fs_info,
"stripe index math went horribly wrong, got stripe_index=%u, num_stripes=%u",
- stripe_index, map->num_stripes);
+ io_geom.stripe_index, map->num_stripes);
ret = -EINVAL;
goto out;
}

- num_alloc_stripes = num_stripes;
+ num_alloc_stripes = io_geom.num_stripes;
if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL &&
op != BTRFS_MAP_READ)
/*
@@ -6555,11 +6566,12 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
* I/O context structure.
*/
if (is_single_device_io(fs_info, smap, map, num_alloc_stripes, op,
- mirror_num)) {
+ io_geom.mirror_num)) {
ret = set_io_stripe(fs_info, op, logical, length, smap, map,
- stripe_index, stripe_offset, stripe_nr);
+ io_geom.stripe_index, io_geom.stripe_offset,
+ io_geom.stripe_nr);
if (mirror_num_ret)
- *mirror_num_ret = mirror_num;
+ *mirror_num_ret = io_geom.mirror_num;
*bioc_ret = NULL;
goto out;
}
@@ -6579,7 +6591,7 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
* It's still mostly the same as other profiles, just with extra rotation.
*/
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK &&
- (op != BTRFS_MAP_READ || mirror_num > 1)) {
+ (op != BTRFS_MAP_READ || io_geom.mirror_num > 1)) {
/*
* For RAID56 @stripe_nr is already the number of full stripes
* before us, which is also the rotation value (needs to modulo
@@ -6589,12 +6601,13 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
* modulo, to reduce one modulo call.
*/
bioc->full_stripe_logical = map->start +
- btrfs_stripe_nr_to_offset(stripe_nr * data_stripes);
- for (int i = 0; i < num_stripes; i++) {
+ btrfs_stripe_nr_to_offset(io_geom.stripe_nr * data_stripes);
+ for (int i = 0; i < io_geom.num_stripes; i++) {
ret = set_io_stripe(fs_info, op, logical, length,
&bioc->stripes[i], map,
- (i + stripe_nr) % num_stripes,
- stripe_offset, stripe_nr);
+ (i + io_geom.stripe_nr) % io_geom.num_stripes,
+ io_geom.stripe_offset,
+ io_geom.stripe_nr);
if (ret < 0)
break;
}
@@ -6603,13 +6616,15 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
* For all other non-RAID56 profiles, just copy the target
* stripe into the bioc.
*/
- for (i = 0; i < num_stripes; i++) {
+ for (i = 0; i < io_geom.num_stripes; i++) {
ret = set_io_stripe(fs_info, op, logical, length,
- &bioc->stripes[i], map, stripe_index,
- stripe_offset, stripe_nr);
+ &bioc->stripes[i], map,
+ io_geom.stripe_index,
+ io_geom.stripe_offset,
+ io_geom.stripe_nr);
if (ret < 0)
break;
- stripe_index++;
+ io_geom.stripe_index++;
}
}

@@ -6620,18 +6635,19 @@ int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
}

if (op != BTRFS_MAP_READ)
- max_errors = btrfs_chunk_max_errors(map);
+ io_geom.max_errors = btrfs_chunk_max_errors(map);

if (dev_replace_is_ongoing && dev_replace->tgtdev != NULL &&
op != BTRFS_MAP_READ) {
handle_ops_on_dev_replace(op, bioc, dev_replace, logical,
- &num_stripes, &max_errors);
+ &io_geom.num_stripes,
+ &io_geom.max_errors);
}

*bioc_ret = bioc;
- bioc->num_stripes = num_stripes;
- bioc->max_errors = max_errors;
- bioc->mirror_num = mirror_num;
+ bioc->num_stripes = io_geom.num_stripes;
+ bioc->max_errors = io_geom.max_errors;
+ bioc->mirror_num = io_geom.mirror_num;

out:
if (dev_replace_is_ongoing) {

--
2.43.0