btrfs: Move and unexport btrfs_rmap_block

It's used only during initial block group reading to map physical
address of super block to a list of logical ones. Make it private to
block-group.c, add proper kernel doc and ensure it's exported only for
tests.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Nikolay Borisov 2019-12-10 19:57:51 +02:00 committed by David Sterba
parent 68c467cbb2
commit 96a14336bd
4 changed files with 91 additions and 71 deletions

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@ -15,6 +15,7 @@
#include "tree-log.h"
#include "delalloc-space.h"
#include "discard.h"
#include "raid56.h"
/*
* Return target flags in extended format or 0 if restripe for this chunk_type
@ -1561,6 +1562,91 @@ static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags)
write_sequnlock(&fs_info->profiles_lock);
}
/**
* btrfs_rmap_block - Map a physical disk address to a list of logical addresses
* @chunk_start: logical address of block group
* @physical: physical address to map to logical addresses
* @logical: return array of logical addresses which map to @physical
* @naddrs: length of @logical
* @stripe_len: size of IO stripe for the given block group
*
* Maps a particular @physical disk address to a list of @logical addresses.
* 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 extent_map *em;
struct map_lookup *map;
u64 *buf;
u64 bytenr;
u64 length;
u64 stripe_nr;
u64 rmap_len;
int i, j, nr = 0;
em = btrfs_get_chunk_map(fs_info, chunk_start, 1);
if (IS_ERR(em))
return -EIO;
map = em->map_lookup;
length = em->len;
rmap_len = map->stripe_len;
if (map->type & BTRFS_BLOCK_GROUP_RAID10)
length = div_u64(length, map->num_stripes / map->sub_stripes);
else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
length = div_u64(length, map->num_stripes);
else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
length = div_u64(length, nr_data_stripes(map));
rmap_len = map->stripe_len * nr_data_stripes(map);
}
buf = kcalloc(map->num_stripes, sizeof(u64), GFP_NOFS);
BUG_ON(!buf); /* -ENOMEM */
for (i = 0; i < map->num_stripes; i++) {
if (map->stripes[i].physical > physical ||
map->stripes[i].physical + length <= physical)
continue;
stripe_nr = physical - map->stripes[i].physical;
stripe_nr = div64_u64(stripe_nr, map->stripe_len);
if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
stripe_nr = stripe_nr * map->num_stripes + i;
stripe_nr = div_u64(stripe_nr, map->sub_stripes);
} else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
stripe_nr = stripe_nr * map->num_stripes + i;
}
/*
* The remaining case would be for RAID56, multiply by
* nr_data_stripes(). Alternatively, just use rmap_len below
* instead of map->stripe_len
*/
bytenr = chunk_start + stripe_nr * rmap_len;
WARN_ON(nr >= map->num_stripes);
for (j = 0; j < nr; j++) {
if (buf[j] == bytenr)
break;
}
if (j == nr) {
WARN_ON(nr >= map->num_stripes);
buf[nr++] = bytenr;
}
}
*logical = buf;
*naddrs = nr;
*stripe_len = rmap_len;
free_extent_map(em);
return 0;
}
static int exclude_super_stripes(struct btrfs_block_group *cache)
{
struct btrfs_fs_info *fs_info = cache->fs_info;

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@ -283,4 +283,9 @@ static inline int btrfs_block_group_done(struct btrfs_block_group *cache)
cache->cached == BTRFS_CACHE_ERROR;
}
#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 */

View File

@ -6114,75 +6114,6 @@ int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
return __btrfs_map_block(fs_info, op, logical, length, bbio_ret, 0, 1);
}
int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
u64 physical, u64 **logical, int *naddrs, int *stripe_len)
{
struct extent_map *em;
struct map_lookup *map;
u64 *buf;
u64 bytenr;
u64 length;
u64 stripe_nr;
u64 rmap_len;
int i, j, nr = 0;
em = btrfs_get_chunk_map(fs_info, chunk_start, 1);
if (IS_ERR(em))
return -EIO;
map = em->map_lookup;
length = em->len;
rmap_len = map->stripe_len;
if (map->type & BTRFS_BLOCK_GROUP_RAID10)
length = div_u64(length, map->num_stripes / map->sub_stripes);
else if (map->type & BTRFS_BLOCK_GROUP_RAID0)
length = div_u64(length, map->num_stripes);
else if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) {
length = div_u64(length, nr_data_stripes(map));
rmap_len = map->stripe_len * nr_data_stripes(map);
}
buf = kcalloc(map->num_stripes, sizeof(u64), GFP_NOFS);
BUG_ON(!buf); /* -ENOMEM */
for (i = 0; i < map->num_stripes; i++) {
if (map->stripes[i].physical > physical ||
map->stripes[i].physical + length <= physical)
continue;
stripe_nr = physical - map->stripes[i].physical;
stripe_nr = div64_u64(stripe_nr, map->stripe_len);
if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
stripe_nr = stripe_nr * map->num_stripes + i;
stripe_nr = div_u64(stripe_nr, map->sub_stripes);
} else if (map->type & BTRFS_BLOCK_GROUP_RAID0) {
stripe_nr = stripe_nr * map->num_stripes + i;
} /* else if RAID[56], multiply by nr_data_stripes().
* Alternatively, just use rmap_len below instead of
* map->stripe_len */
bytenr = chunk_start + stripe_nr * rmap_len;
WARN_ON(nr >= map->num_stripes);
for (j = 0; j < nr; j++) {
if (buf[j] == bytenr)
break;
}
if (j == nr) {
WARN_ON(nr >= map->num_stripes);
buf[nr++] = bytenr;
}
}
*logical = buf;
*naddrs = nr;
*stripe_len = rmap_len;
free_extent_map(em);
return 0;
}
static inline void btrfs_end_bbio(struct btrfs_bio *bbio, struct bio *bio)
{
bio->bi_private = bbio->private;

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@ -415,8 +415,6 @@ int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
struct btrfs_bio **bbio_ret);
int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
u64 logical, u64 len, struct btrfs_io_geometry *io_geom);
int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
u64 physical, u64 **logical, int *naddrs, int *stripe_len);
int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, u64 type);