include/linux/buffer_head.h

51  * Historically, a buffer_head was used to map a single block
53  * filesystem and block layers.  Nowadays the basic I/O unit
54  * is the bio, and buffer_heads are used for extracting block
67 	sector_t b_blocknr;		/* start block number */
215 void clean_bdev_aliases(struct block_device *bdev, sector_t block,
225 struct buffer_head *__find_get_block(struct block_device *bdev, sector_t block,
227 struct buffer_head *bdev_getblk(struct block_device *bdev, sector_t block,
231 void __breadahead(struct block_device *, sector_t block, unsigned int size);
233 				sector_t block, unsigned size, gfp_t gfp);
319 sb_bread(struct super_block *sb, sector_t block)
321 	return __bread_gfp(sb->s_bdev, block, sb->s_blocksize, __GFP_MOVABLE);
325 sb_bread_unmovable(struct super_block *sb, sector_t block)
327 	return __bread_gfp(sb->s_bdev, block, sb->s_blocksize, 0);
331 sb_breadahead(struct super_block *sb, sector_t block)
333 	__breadahead(sb->s_bdev, block, sb->s_blocksize);
337 		sector_t block, unsigned size)
344 	return bdev_getblk(bdev, block, size, gfp);
348 		sector_t block, unsigned size)
355 	return bdev_getblk(bdev, block, size, gfp);
359 		sector_t block)
361 	return __getblk(sb->s_bdev, block, sb->s_blocksize);
365 		sector_t block, gfp_t gfp)
367 	return bdev_getblk(sb->s_bdev, block, sb->s_blocksize, gfp);
371 sb_find_get_block(struct super_block *sb, sector_t block)
373 	return __find_get_block(sb->s_bdev, block, sb->s_blocksize);
377 map_bh(struct buffer_head *bh, struct super_block *sb, sector_t block)
381 	bh->b_blocknr = block;
440  *  __bread() - reads a specified block and returns the bh
442  *  @block: number of block
445  *  Reads a specified block, and returns buffer head that contains it.
447  *  It returns NULL if the block was unreadable.
450 __bread(struct block_device *bdev, sector_t block, unsigned size)
452 	return __bread_gfp(bdev, block, size, __GFP_MOVABLE);
462  * divided by the block size.  It can be used for other purposes, but