Commit 96a14336 authored by Nikolay Borisov's avatar Nikolay Borisov Committed by David Sterba
Browse files

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: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 68c467cb

fs/btrfs/block-group.c

+86 −0
Original line number Diff line number Diff line
@@ -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;

fs/btrfs/block-group.h

+5 −0
Original line number Diff line number Diff line
@@ -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 */

fs/btrfs/volumes.c

+0 −69
Original line number Diff line number Diff line
@@ -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;

fs/btrfs/volumes.h

+0 −2
Original line number Diff line number Diff line
@@ -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);

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