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Commit db55d922 authored by Ryusuke Konishi's avatar Ryusuke Konishi
Browse files

nilfs2: add kernel doc comments to persistent object allocator functions 



The implementation of persistent object allocator (alloc.c) is poorly
documented.  This adds kernel doc style comments on that functions.

Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
parent fdce895e

fs/nilfs2/alloc.c

+153 −1
Original line number Diff line number Diff line
@@ -31,6 +31,11 @@ 
#include "alloc.h"





/**

 * nilfs_palloc_groups_per_desc_block - get the number of groups that a group

 *					descriptor block can maintain

 * @inode: inode of metadata file using this allocator

 */

static inline unsigned long

nilfs_palloc_groups_per_desc_block(const struct inode *inode)

{
@@ -38,12 +43,21 @@ nilfs_palloc_groups_per_desc_block(const struct inode *inode) 
		sizeof(struct nilfs_palloc_group_desc);

}



/**

 * nilfs_palloc_groups_count - get maximum number of groups

 * @inode: inode of metadata file using this allocator

 */

static inline unsigned long

nilfs_palloc_groups_count(const struct inode *inode)

{

	return 1UL << (BITS_PER_LONG - (inode->i_blkbits + 3 /* log2(8) */));

}



/**

 * nilfs_palloc_init_blockgroup - initialize private variables for allocator

 * @inode: inode of metadata file using this allocator

 * @entry_size: size of the persistent object

 */

int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned entry_size)

{

	struct nilfs_mdt_info *mi = NILFS_MDT(inode);
@@ -69,6 +83,12 @@ int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned entry_size) 
	return 0;

}



/**

 * nilfs_palloc_group - get group number and offset from an entry number

 * @inode: inode of metadata file using this allocator

 * @nr: serial number of the entry (e.g. inode number)

 * @offset: pointer to store offset number in the group

 */

static unsigned long nilfs_palloc_group(const struct inode *inode, __u64 nr,

					unsigned long *offset)

{
@@ -78,6 +98,14 @@ static unsigned long nilfs_palloc_group(const struct inode *inode, __u64 nr, 
	return group;

}



/**

 * nilfs_palloc_desc_blkoff - get block offset of a group descriptor block

 * @inode: inode of metadata file using this allocator

 * @group: group number

 *

 * nilfs_palloc_desc_blkoff() returns block offset of the descriptor

 * block which contains a descriptor of the specified group.

 */

static unsigned long

nilfs_palloc_desc_blkoff(const struct inode *inode, unsigned long group)

{
@@ -86,6 +114,14 @@ nilfs_palloc_desc_blkoff(const struct inode *inode, unsigned long group) 
	return desc_block * NILFS_MDT(inode)->mi_blocks_per_desc_block;

}



/**

 * nilfs_palloc_bitmap_blkoff - get block offset of a bitmap block

 * @inode: inode of metadata file using this allocator

 * @group: group number

 *

 * nilfs_palloc_bitmap_blkoff() returns block offset of the bitmap

 * block used to allocate/deallocate entries in the specified group.

 */

static unsigned long

nilfs_palloc_bitmap_blkoff(const struct inode *inode, unsigned long group)

{
@@ -95,6 +131,12 @@ nilfs_palloc_bitmap_blkoff(const struct inode *inode, unsigned long group) 
		desc_offset * NILFS_MDT(inode)->mi_blocks_per_group;

}



/**

 * nilfs_palloc_group_desc_nfrees - get the number of free entries in a group

 * @inode: inode of metadata file using this allocator

 * @group: group number

 * @desc: pointer to descriptor structure for the group

 */

static unsigned long

nilfs_palloc_group_desc_nfrees(struct inode *inode, unsigned long group,

			       const struct nilfs_palloc_group_desc *desc)
@@ -107,6 +149,13 @@ nilfs_palloc_group_desc_nfrees(struct inode *inode, unsigned long group, 
	return nfree;

}



/**

 * nilfs_palloc_group_desc_add_entries - adjust count of free entries

 * @inode: inode of metadata file using this allocator

 * @group: group number

 * @desc: pointer to descriptor structure for the group

 * @n: delta to be added

 */

static void

nilfs_palloc_group_desc_add_entries(struct inode *inode,

				    unsigned long group,
@@ -118,6 +167,11 @@ nilfs_palloc_group_desc_add_entries(struct inode *inode, 
	spin_unlock(nilfs_mdt_bgl_lock(inode, group));

}



/**

 * nilfs_palloc_entry_blkoff - get block offset of an entry block

 * @inode: inode of metadata file using this allocator

 * @nr: serial number of the entry (e.g. inode number)

 */

static unsigned long

nilfs_palloc_entry_blkoff(const struct inode *inode, __u64 nr)

{
@@ -129,6 +183,12 @@ nilfs_palloc_entry_blkoff(const struct inode *inode, __u64 nr) 
		group_offset / NILFS_MDT(inode)->mi_entries_per_block;

}



/**

 * nilfs_palloc_desc_block_init - initialize buffer of a group descriptor block

 * @inode: inode of metadata file

 * @bh: buffer head of the buffer to be initialized

 * @kaddr: kernel address mapped for the page including the buffer

 */

static void nilfs_palloc_desc_block_init(struct inode *inode,

					 struct buffer_head *bh, void *kaddr)

{
@@ -179,6 +239,13 @@ static int nilfs_palloc_get_block(struct inode *inode, unsigned long blkoff, 
	return ret;

}



/**

 * nilfs_palloc_get_desc_block - get buffer head of a group descriptor block

 * @inode: inode of metadata file using this allocator

 * @group: group number

 * @create: create flag

 * @bhp: pointer to store the resultant buffer head

 */

static int nilfs_palloc_get_desc_block(struct inode *inode,

				       unsigned long group,

				       int create, struct buffer_head **bhp)
@@ -191,6 +258,13 @@ static int nilfs_palloc_get_desc_block(struct inode *inode, 
				      bhp, &cache->prev_desc, &cache->lock);

}



/**

 * nilfs_palloc_get_bitmap_block - get buffer head of a bitmap block

 * @inode: inode of metadata file using this allocator

 * @group: group number

 * @create: create flag

 * @bhp: pointer to store the resultant buffer head

 */

static int nilfs_palloc_get_bitmap_block(struct inode *inode,

					 unsigned long group,

					 int create, struct buffer_head **bhp)
@@ -203,6 +277,13 @@ static int nilfs_palloc_get_bitmap_block(struct inode *inode, 
				      &cache->prev_bitmap, &cache->lock);

}



/**

 * nilfs_palloc_get_entry_block - get buffer head of an entry block

 * @inode: inode of metadata file using this allocator

 * @nr: serial number of the entry (e.g. inode number)

 * @create: create flag

 * @bhp: pointer to store the resultant buffer head

 */

int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,

				 int create, struct buffer_head **bhp)

{
@@ -214,6 +295,13 @@ int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr, 
				      &cache->prev_entry, &cache->lock);

}



/**

 * nilfs_palloc_block_get_group_desc - get kernel address of a group descriptor

 * @inode: inode of metadata file using this allocator

 * @group: group number

 * @bh: buffer head of the buffer storing the group descriptor block

 * @kaddr: kernel address mapped for the page including the buffer

 */

static struct nilfs_palloc_group_desc *

nilfs_palloc_block_get_group_desc(const struct inode *inode,

				  unsigned long group,
@@ -223,6 +311,13 @@ nilfs_palloc_block_get_group_desc(const struct inode *inode, 
		group % nilfs_palloc_groups_per_desc_block(inode);

}



/**

 * nilfs_palloc_block_get_entry - get kernel address of an entry

 * @inode: inode of metadata file using this allocator

 * @nr: serial number of the entry (e.g. inode number)

 * @bh: buffer head of the buffer storing the entry block

 * @kaddr: kernel address mapped for the page including the buffer

 */

void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,

				   const struct buffer_head *bh, void *kaddr)

{
@@ -235,11 +330,19 @@ void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr, 
		entry_offset * NILFS_MDT(inode)->mi_entry_size;

}



/**

 * nilfs_palloc_find_available_slot - find available slot in a group

 * @inode: inode of metadata file using this allocator

 * @group: group number

 * @target: offset number of an entry in the group (start point)

 * @bitmap: bitmap of the group

 * @bsize: size in bits

 */

static int nilfs_palloc_find_available_slot(struct inode *inode,

					    unsigned long group,

					    unsigned long target,

					    unsigned char *bitmap,

					    int bsize)  /* size in bits */

					    int bsize)

{

	int curr, pos, end, i;
@@ -277,6 +380,13 @@ static int nilfs_palloc_find_available_slot(struct inode *inode, 
	return -ENOSPC;

}



/**

 * nilfs_palloc_rest_groups_in_desc_block - get the remaining number of groups

 *					    in a group descriptor block

 * @inode: inode of metadata file using this allocator

 * @curr: current group number

 * @max: maximum number of groups

 */

static unsigned long

nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,

				       unsigned long curr, unsigned long max)
@@ -287,6 +397,11 @@ nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode, 
		     max - curr + 1);

}



/**

 * nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object

 * @inode: inode of metadata file using this allocator

 * @req: nilfs_palloc_req structure exchanged for the allocation

 */

int nilfs_palloc_prepare_alloc_entry(struct inode *inode,

				     struct nilfs_palloc_req *req)

{
@@ -366,6 +481,11 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode, 
	return ret;

}



/**

 * nilfs_palloc_commit_alloc_entry - finish allocation of a persistent object

 * @inode: inode of metadata file using this allocator

 * @req: nilfs_palloc_req structure exchanged for the allocation

 */

void nilfs_palloc_commit_alloc_entry(struct inode *inode,

				     struct nilfs_palloc_req *req)

{
@@ -377,6 +497,11 @@ void nilfs_palloc_commit_alloc_entry(struct inode *inode, 
	brelse(req->pr_desc_bh);

}



/**

 * nilfs_palloc_commit_free_entry - finish deallocating a persistent object

 * @inode: inode of metadata file using this allocator

 * @req: nilfs_palloc_req structure exchanged for the removal

 */

void nilfs_palloc_commit_free_entry(struct inode *inode,

				    struct nilfs_palloc_req *req)

{
@@ -410,6 +535,11 @@ void nilfs_palloc_commit_free_entry(struct inode *inode, 
	brelse(req->pr_desc_bh);

}



/**

 * nilfs_palloc_abort_alloc_entry - cancel allocation of a persistent object

 * @inode: inode of metadata file using this allocator

 * @req: nilfs_palloc_req structure exchanged for the allocation

 */

void nilfs_palloc_abort_alloc_entry(struct inode *inode,

				    struct nilfs_palloc_req *req)

{
@@ -442,6 +572,11 @@ void nilfs_palloc_abort_alloc_entry(struct inode *inode, 
	req->pr_desc_bh = NULL;

}



/**

 * nilfs_palloc_prepare_free_entry - prepare to deallocate a persistent object

 * @inode: inode of metadata file using this allocator

 * @req: nilfs_palloc_req structure exchanged for the removal

 */

int nilfs_palloc_prepare_free_entry(struct inode *inode,

				    struct nilfs_palloc_req *req)

{
@@ -464,6 +599,11 @@ int nilfs_palloc_prepare_free_entry(struct inode *inode, 
	return 0;

}



/**

 * nilfs_palloc_abort_free_entry - cancel deallocating a persistent object

 * @inode: inode of metadata file using this allocator

 * @req: nilfs_palloc_req structure exchanged for the removal

 */

void nilfs_palloc_abort_free_entry(struct inode *inode,

				   struct nilfs_palloc_req *req)

{
@@ -475,6 +615,12 @@ void nilfs_palloc_abort_free_entry(struct inode *inode, 
	req->pr_desc_bh = NULL;

}



/**

 * nilfs_palloc_group_is_in - judge if an entry is in a group

 * @inode: inode of metadata file using this allocator

 * @group: group number

 * @nr: serial number of the entry (e.g. inode number)

 */

static int

nilfs_palloc_group_is_in(struct inode *inode, unsigned long group, __u64 nr)

{
@@ -485,6 +631,12 @@ nilfs_palloc_group_is_in(struct inode *inode, unsigned long group, __u64 nr) 
	return (nr >= first) && (nr <= last);

}



/**

 * nilfs_palloc_freev - deallocate a set of persistent objects

 * @inode: inode of metadata file using this allocator

 * @entry_nrs: array of entry numbers to be deallocated

 * @nitems: number of entries stored in @entry_nrs

 */

int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)

{

	struct buffer_head *desc_bh, *bitmap_bh;

fs/nilfs2/alloc.h

+7 −0
Original line number Diff line number Diff line
@@ -29,6 +29,13 @@ 
#include <linux/buffer_head.h>

#include <linux/fs.h>



/**

 * nilfs_palloc_entries_per_group - get the number of entries per group

 * @inode: inode of metadata file using this allocator

 *

 * The number of entries per group is defined by the number of bits

 * that a bitmap block can maintain.

 */

static inline unsigned long

nilfs_palloc_entries_per_group(const struct inode *inode)

{