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Commit 5b20384f authored by Ryusuke Konishi's avatar Ryusuke Konishi Committed by Linus Torvalds
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nilfs2: add bmap function to seek a valid key 



Add a new bmap function, nilfs_bmap_seek_key(), which seeks a valid
entry and returns its key starting from a given key.  This function
can be used to skip hole blocks efficiently.

Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3568a13f

fs/nilfs2/bmap.c

+31 −0
Original line number Diff line number Diff line
@@ -189,6 +189,37 @@ static int nilfs_bmap_do_delete(struct nilfs_bmap *bmap, __u64 key) 
	return bmap->b_ops->bop_delete(bmap, key);

}



/**

 * nilfs_bmap_seek_key - seek a valid entry and return its key

 * @bmap: bmap struct

 * @start: start key number

 * @keyp: place to store valid key

 *

 * Description: nilfs_bmap_seek_key() seeks a valid key on @bmap

 * starting from @start, and stores it to @keyp if found.

 *

 * Return Value: On success, 0 is returned. On error, one of the following

 * negative error codes is returned.

 *

 * %-EIO - I/O error.

 *

 * %-ENOMEM - Insufficient amount of memory available.

 *

 * %-ENOENT - No valid entry was found

 */

int nilfs_bmap_seek_key(struct nilfs_bmap *bmap, __u64 start, __u64 *keyp)

{

	int ret;



	down_read(&bmap->b_sem);

	ret = bmap->b_ops->bop_seek_key(bmap, start, keyp);

	up_read(&bmap->b_sem);



	if (ret < 0)

		ret = nilfs_bmap_convert_error(bmap, __func__, ret);

	return ret;

}



int nilfs_bmap_last_key(struct nilfs_bmap *bmap, __u64 *keyp)

{

	int ret;

fs/nilfs2/bmap.h

+4 −1
Original line number Diff line number Diff line
@@ -76,8 +76,10 @@ struct nilfs_bmap_operations { 
			  union nilfs_binfo *);

	int (*bop_mark)(struct nilfs_bmap *, __u64, int);



	/* The following functions are internal use only. */

	int (*bop_seek_key)(const struct nilfs_bmap *, __u64, __u64 *);

	int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);



	/* The following functions are internal use only. */

	int (*bop_check_insert)(const struct nilfs_bmap *, __u64);

	int (*bop_check_delete)(struct nilfs_bmap *, __u64);

	int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int);
@@ -155,6 +157,7 @@ void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *); 
int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned);

int nilfs_bmap_insert(struct nilfs_bmap *bmap, __u64 key, unsigned long rec);

int nilfs_bmap_delete(struct nilfs_bmap *bmap, __u64 key);

int nilfs_bmap_seek_key(struct nilfs_bmap *bmap, __u64 start, __u64 *keyp);

int nilfs_bmap_last_key(struct nilfs_bmap *bmap, __u64 *keyp);

int nilfs_bmap_truncate(struct nilfs_bmap *bmap, __u64 key);

void nilfs_bmap_clear(struct nilfs_bmap *);

fs/nilfs2/btree.c

+63 −0
Original line number Diff line number Diff line
@@ -633,6 +633,44 @@ static int nilfs_btree_do_lookup_last(const struct nilfs_bmap *btree, 
	return 0;

}



/**

 * nilfs_btree_get_next_key - get next valid key from btree path array

 * @btree: bmap struct of btree

 * @path: array of nilfs_btree_path struct

 * @minlevel: start level

 * @nextkey: place to store the next valid key

 *

 * Return Value: If a next key was found, 0 is returned. Otherwise,

 * -ENOENT is returned.

 */

static int nilfs_btree_get_next_key(const struct nilfs_bmap *btree,

				    const struct nilfs_btree_path *path,

				    int minlevel, __u64 *nextkey)

{

	struct nilfs_btree_node *node;

	int maxlevel = nilfs_btree_height(btree) - 1;

	int index, next_adj, level;



	/* Next index is already set to bp_index for leaf nodes. */

	next_adj = 0;

	for (level = minlevel; level <= maxlevel; level++) {

		if (level == maxlevel)

			node = nilfs_btree_get_root(btree);

		else

			node = nilfs_btree_get_nonroot_node(path, level);



		index = path[level].bp_index + next_adj;

		if (index < nilfs_btree_node_get_nchildren(node)) {

			/* Next key is in this node */

			*nextkey = nilfs_btree_node_get_key(node, index);

			return 0;

		}

		/* For non-leaf nodes, next index is stored at bp_index + 1. */

		next_adj = 1;

	}

	return -ENOENT;

}



static int nilfs_btree_lookup(const struct nilfs_bmap *btree,

			      __u64 key, int level, __u64 *ptrp)

{
@@ -1563,6 +1601,27 @@ static int nilfs_btree_delete(struct nilfs_bmap *btree, __u64 key) 
	return ret;

}



static int nilfs_btree_seek_key(const struct nilfs_bmap *btree, __u64 start,

				__u64 *keyp)

{

	struct nilfs_btree_path *path;

	const int minlevel = NILFS_BTREE_LEVEL_NODE_MIN;

	int ret;



	path = nilfs_btree_alloc_path();

	if (!path)

		return -ENOMEM;



	ret = nilfs_btree_do_lookup(btree, path, start, NULL, minlevel, 0);

	if (!ret)

		*keyp = start;

	else if (ret == -ENOENT)

		ret = nilfs_btree_get_next_key(btree, path, minlevel, keyp);



	nilfs_btree_free_path(path);

	return ret;

}



static int nilfs_btree_last_key(const struct nilfs_bmap *btree, __u64 *keyp)

{

	struct nilfs_btree_path *path;
@@ -2298,7 +2357,9 @@ static const struct nilfs_bmap_operations nilfs_btree_ops = { 
	.bop_assign		=	nilfs_btree_assign,

	.bop_mark		=	nilfs_btree_mark,



	.bop_seek_key		=	nilfs_btree_seek_key,

	.bop_last_key		=	nilfs_btree_last_key,



	.bop_check_insert	=	NULL,

	.bop_check_delete	=	nilfs_btree_check_delete,

	.bop_gather_data	=	nilfs_btree_gather_data,
@@ -2318,7 +2379,9 @@ static const struct nilfs_bmap_operations nilfs_btree_ops_gc = { 
	.bop_assign		=	nilfs_btree_assign_gc,

	.bop_mark		=	NULL,



	.bop_seek_key		=	NULL,

	.bop_last_key		=	NULL,



	.bop_check_insert	=	NULL,

	.bop_check_delete	=	NULL,

	.bop_gather_data	=	NULL,

fs/nilfs2/direct.c

+17 −0
Original line number Diff line number Diff line
@@ -173,6 +173,21 @@ static int nilfs_direct_delete(struct nilfs_bmap *bmap, __u64 key) 
	return ret;

}



static int nilfs_direct_seek_key(const struct nilfs_bmap *direct, __u64 start,

				 __u64 *keyp)

{

	__u64 key;



	for (key = start; key <= NILFS_DIRECT_KEY_MAX; key++) {

		if (nilfs_direct_get_ptr(direct, key) !=

		    NILFS_BMAP_INVALID_PTR) {

			*keyp = key;

			return 0;

		}

	}

	return -ENOENT;

}



static int nilfs_direct_last_key(const struct nilfs_bmap *direct, __u64 *keyp)

{

	__u64 key, lastkey;
@@ -355,7 +370,9 @@ static const struct nilfs_bmap_operations nilfs_direct_ops = { 
	.bop_assign		=	nilfs_direct_assign,

	.bop_mark		=	NULL,



	.bop_seek_key		=	nilfs_direct_seek_key,

	.bop_last_key		=	nilfs_direct_last_key,



	.bop_check_insert	=	nilfs_direct_check_insert,

	.bop_check_delete	=	NULL,

	.bop_gather_data	=	nilfs_direct_gather_data,