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Commit da019954 authored by Ryusuke Konishi's avatar Ryusuke Konishi Committed by Linus Torvalds
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nilfs2: add helper functions to delete blocks from dat file 



This adds delete functions for data blocks of metadata files using bitmap
based allocator.  nilfs_palloc_delete_entry_block() deletes an entry block
(e.g.  block storing dat entries), and nilfs_palloc_delete_bitmap_block()
deletes a bitmap block, respectively.

These helpers are intended to be used in the successive change on
deallocator of block addresses ("nilfs2: free unused dat file blocks
during garbage collection").

Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b2258094

fs/nilfs2/alloc.c

+50 −0
Original line number Diff line number Diff line
@@ -235,6 +235,26 @@ static int nilfs_palloc_get_block(struct inode *inode, unsigned long blkoff, 
	return ret;

}



/**

 * nilfs_palloc_delete_block - delete a block on the persistent allocator file

 * @inode: inode of metadata file using this allocator

 * @blkoff: block offset

 * @prev: nilfs_bh_assoc struct of the last used buffer

 * @lock: spin lock protecting @prev

 */

static int nilfs_palloc_delete_block(struct inode *inode, unsigned long blkoff,

				     struct nilfs_bh_assoc *prev,

				     spinlock_t *lock)

{

	spin_lock(lock);

	if (prev->bh && blkoff == prev->blkoff) {

		brelse(prev->bh);

		prev->bh = NULL;

	}

	spin_unlock(lock);

	return nilfs_mdt_delete_block(inode, blkoff);

}



/**

 * nilfs_palloc_get_desc_block - get buffer head of a group descriptor block

 * @inode: inode of metadata file using this allocator
@@ -273,6 +293,22 @@ static int nilfs_palloc_get_bitmap_block(struct inode *inode, 
				      &cache->prev_bitmap, &cache->lock);

}



/**

 * nilfs_palloc_delete_bitmap_block - delete a bitmap block

 * @inode: inode of metadata file using this allocator

 * @group: group number

 */

static int nilfs_palloc_delete_bitmap_block(struct inode *inode,

					    unsigned long group)

{

	struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;



	return nilfs_palloc_delete_block(inode,

					 nilfs_palloc_bitmap_blkoff(inode,

								    group),

					 &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
@@ -291,6 +327,20 @@ int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr, 
				      &cache->prev_entry, &cache->lock);

}



/**

 * nilfs_palloc_delete_entry_block - delete an entry block

 * @inode: inode of metadata file using this allocator

 * @nr: serial number of the entry

 */

static int nilfs_palloc_delete_entry_block(struct inode *inode, __u64 nr)

{

	struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;



	return nilfs_palloc_delete_block(inode,

					 nilfs_palloc_entry_blkoff(inode, 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