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btrfs: replace map_lookup->stripe_len by BTRFS_STRIPE_LEN
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Currently btrfs doesn't support stripe lengths other than 64KiB.
This is already set in the tree-checker.

There is really no meaning to record that fixed value in map_lookup for
now, and can all be replaced with BTRFS_STRIPE_LEN.

Furthermore we can use the fix stripe length to do the following
optimization:

- Use BTRFS_STRIPE_LEN_SHIFT to replace some 64bit division
  Now we only need to do a right shift.

  And the value of BTRFS_STRIPE_LEN itself is already too large for bit
  shift, thus if we accidentally use BTRFS_STRIPE_LEN to do bit shift,
  a compiler warning would be triggered.

  Thus this bit shift optimization would be safe.

- Use BTRFS_STRIPE_LEN_MASK to calculate the offset inside a stripe

Reviewed-by: Johannes Thumshirn <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Qu Wenruo <[email protected]>
Reviewed-by: David Sterba <[email protected]>
Signed-off-by: David Sterba <[email protected]>
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@adam900710 @kdave
adam900710 authored and kdave committed Apr 17, 2023
1 parent dcb2137 commit a97699d
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Showing 5 changed files with 66 additions and 60 deletions.
10 changes: 6 additions & 4 deletions fs/btrfs/block-group.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1977,12 +1977,12 @@ 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;
io_stripe_size = BTRFS_STRIPE_LEN;
chunk_start = em->start;

/* For RAID5/6 adjust to a full IO stripe length */
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
io_stripe_size = map->stripe_len * nr_data_stripes(map);
io_stripe_size = nr_data_stripes(map) << BTRFS_STRIPE_LEN_SHIFT;

buf = kcalloc(map->num_stripes, sizeof(u64), GFP_NOFS);
if (!buf) {
Expand All @@ -2000,8 +2000,10 @@ int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
data_stripe_length))
continue;

stripe_nr = physical - map->stripes[i].physical;
stripe_nr = div64_u64_rem(stripe_nr, map->stripe_len, &offset);
stripe_nr = (physical - map->stripes[i].physical) >>
BTRFS_STRIPE_LEN_SHIFT;
offset = (physical - map->stripes[i].physical) &
BTRFS_STRIPE_LEN_MASK;

if (map->type & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID10)) {
Expand Down
43 changes: 21 additions & 22 deletions fs/btrfs/scrub.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2722,7 +2722,7 @@ static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map,

if (flags & BTRFS_EXTENT_FLAG_DATA) {
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
blocksize = map->stripe_len;
blocksize = BTRFS_STRIPE_LEN;
else
blocksize = sctx->fs_info->sectorsize;
spin_lock(&sctx->stat_lock);
Expand All @@ -2731,7 +2731,7 @@ static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map,
spin_unlock(&sctx->stat_lock);
} else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK)
blocksize = map->stripe_len;
blocksize = BTRFS_STRIPE_LEN;
else
blocksize = sctx->fs_info->nodesize;
spin_lock(&sctx->stat_lock);
Expand Down Expand Up @@ -2920,9 +2920,9 @@ static int get_raid56_logic_offset(u64 physical, int num,

*offset = last_offset;
for (i = 0; i < data_stripes; i++) {
*offset = last_offset + i * map->stripe_len;
*offset = last_offset + (i << BTRFS_STRIPE_LEN_SHIFT);

stripe_nr = div64_u64(*offset, map->stripe_len);
stripe_nr = *offset >> BTRFS_STRIPE_LEN_SHIFT;
stripe_nr = div_u64(stripe_nr, data_stripes);

/* Work out the disk rotation on this stripe-set */
Expand All @@ -2935,7 +2935,7 @@ static int get_raid56_logic_offset(u64 physical, int num,
if (stripe_index < num)
j++;
}
*offset = last_offset + j * map->stripe_len;
*offset = last_offset + (j << BTRFS_STRIPE_LEN_SHIFT);
return 1;
}

Expand Down Expand Up @@ -3205,7 +3205,7 @@ static int scrub_raid56_data_stripe_for_parity(struct scrub_ctx *sctx,
/* Path must not be populated */
ASSERT(!path->nodes[0]);

while (cur_logical < logical + map->stripe_len) {
while (cur_logical < logical + BTRFS_STRIPE_LEN) {
struct btrfs_io_context *bioc = NULL;
struct btrfs_device *extent_dev;
u64 extent_start;
Expand All @@ -3217,7 +3217,7 @@ static int scrub_raid56_data_stripe_for_parity(struct scrub_ctx *sctx,
u64 extent_mirror_num;

ret = find_first_extent_item(extent_root, path, cur_logical,
logical + map->stripe_len - cur_logical);
logical + BTRFS_STRIPE_LEN - cur_logical);
/* No more extent item in this data stripe */
if (ret > 0) {
ret = 0;
Expand All @@ -3231,7 +3231,7 @@ static int scrub_raid56_data_stripe_for_parity(struct scrub_ctx *sctx,
/* Metadata should not cross stripe boundaries */
if ((extent_flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) &&
does_range_cross_boundary(extent_start, extent_size,
logical, map->stripe_len)) {
logical, BTRFS_STRIPE_LEN)) {
btrfs_err(fs_info,
"scrub: tree block %llu spanning stripes, ignored. logical=%llu",
extent_start, logical);
Expand All @@ -3247,7 +3247,7 @@ static int scrub_raid56_data_stripe_for_parity(struct scrub_ctx *sctx,

/* Truncate the range inside this data stripe */
extent_size = min(extent_start + extent_size,
logical + map->stripe_len) - cur_logical;
logical + BTRFS_STRIPE_LEN) - cur_logical;
extent_start = cur_logical;
ASSERT(extent_size <= U32_MAX);

Expand Down Expand Up @@ -3320,8 +3320,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
path->search_commit_root = 1;
path->skip_locking = 1;

ASSERT(map->stripe_len <= U32_MAX);
nsectors = map->stripe_len >> fs_info->sectorsize_bits;
nsectors = BTRFS_STRIPE_LEN >> fs_info->sectorsize_bits;
ASSERT(nsectors <= BITS_PER_LONG);
sparity = kzalloc(sizeof(struct scrub_parity), GFP_NOFS);
if (!sparity) {
Expand All @@ -3332,8 +3331,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,
return -ENOMEM;
}

ASSERT(map->stripe_len <= U32_MAX);
sparity->stripe_len = map->stripe_len;
sparity->stripe_len = BTRFS_STRIPE_LEN;
sparity->nsectors = nsectors;
sparity->sctx = sctx;
sparity->scrub_dev = sdev;
Expand All @@ -3344,7 +3342,7 @@ static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx,

ret = 0;
for (cur_logical = logic_start; cur_logical < logic_end;
cur_logical += map->stripe_len) {
cur_logical += BTRFS_STRIPE_LEN) {
ret = scrub_raid56_data_stripe_for_parity(sctx, sparity, map,
sdev, path, cur_logical);
if (ret < 0)
Expand Down Expand Up @@ -3536,7 +3534,7 @@ static u64 simple_stripe_full_stripe_len(const struct map_lookup *map)
ASSERT(map->type & (BTRFS_BLOCK_GROUP_RAID0 |
BTRFS_BLOCK_GROUP_RAID10));

return map->num_stripes / map->sub_stripes * map->stripe_len;
return (map->num_stripes / map->sub_stripes) << BTRFS_STRIPE_LEN_SHIFT;
}

/* Get the logical bytenr for the stripe */
Expand All @@ -3552,7 +3550,8 @@ static u64 simple_stripe_get_logical(struct map_lookup *map,
* (stripe_index / sub_stripes) gives how many data stripes we need to
* skip.
*/
return (stripe_index / map->sub_stripes) * map->stripe_len + bg->start;
return ((stripe_index / map->sub_stripes) << BTRFS_STRIPE_LEN_SHIFT) +
bg->start;
}

/* Get the mirror number for the stripe */
Expand Down Expand Up @@ -3589,14 +3588,14 @@ static int scrub_simple_stripe(struct scrub_ctx *sctx,
* this stripe.
*/
ret = scrub_simple_mirror(sctx, extent_root, csum_root, bg, map,
cur_logical, map->stripe_len, device,
cur_logical, BTRFS_STRIPE_LEN, device,
cur_physical, mirror_num);
if (ret)
return ret;
/* Skip to next stripe which belongs to the target device */
cur_logical += logical_increment;
/* For physical offset, we just go to next stripe */
cur_physical += map->stripe_len;
cur_physical += BTRFS_STRIPE_LEN;
}
return ret;
}
Expand Down Expand Up @@ -3690,7 +3689,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
if (profile & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID10)) {
ret = scrub_simple_stripe(sctx, root, csum_root, bg, map,
scrub_dev, stripe_index);
offset = map->stripe_len * (stripe_index / map->sub_stripes);
offset = (stripe_index / map->sub_stripes) << BTRFS_STRIPE_LEN_SHIFT;
goto out;
}

Expand All @@ -3705,7 +3704,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,

/* Initialize @offset in case we need to go to out: label */
get_raid56_logic_offset(physical, stripe_index, map, &offset, NULL);
increment = map->stripe_len * nr_data_stripes(map);
increment = nr_data_stripes(map) << BTRFS_STRIPE_LEN_SHIFT;

/*
* Due to the rotation, for RAID56 it's better to iterate each stripe
Expand Down Expand Up @@ -3736,13 +3735,13 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx,
* is still based on @mirror_num.
*/
ret = scrub_simple_mirror(sctx, root, csum_root, bg, map,
logical, map->stripe_len,
logical, BTRFS_STRIPE_LEN,
scrub_dev, physical, 1);
if (ret < 0)
goto out;
next:
logical += increment;
physical += map->stripe_len;
physical += BTRFS_STRIPE_LEN;
spin_lock(&sctx->stat_lock);
if (stop_loop)
sctx->stat.last_physical =
Expand Down
1 change: 0 additions & 1 deletion fs/btrfs/tests/extent-map-tests.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -486,7 +486,6 @@ static int test_rmap_block(struct btrfs_fs_info *fs_info,
em->map_lookup = map;

map->num_stripes = test->num_stripes;
map->stripe_len = BTRFS_STRIPE_LEN;
map->type = test->raid_type;

for (i = 0; i < map->num_stripes; i++) {
Expand Down
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