![[PukiWiki]](image/pukiwiki.png "[PukiWiki]")
*参照元 [#h78e9fc2] #backlinks *説明 [#xa3aaebf] -パス: [[linux-2.6.33/include/linux/buffer_head.h]] -FIXME: これは何？ --説明 **参考 [#r8d69890] *実装 [#w09c33b5] /* * Historically, a buffer_head was used to map a single block * within a page, and of course as the unit of I/O through the * filesystem and block layers. Nowadays the basic I/O unit * is the bio, and buffer_heads are used for extracting block * mappings (via a get_block_t call), for tracking state within * a page (via a page_mapping) and for wrapping bio submission * for backward compatibility reasons (e.g. submit_bh). */ struct buffer_head { unsigned long b_state; /* buffer state bitmap (see above) */ struct buffer_head *b_this_page;/* circular list of page's buffers */ - --[[linux-2.6.33/buffer_head]] struct page *b_page; /* the page this bh is mapped to */ - --[[linux-2.6.33/page]] sector_t b_blocknr; /* start block number */ - --[[linux-2.6.33/sector_t]] size_t b_size; /* size of mapping */ char *b_data; /* pointer to data within the page */ struct block_device *b_bdev; - --[[linux-2.6.33/block_device]] bh_end_io_t *b_end_io; /* I/O completion */ - --[[linux-2.6.33/bh_end_io_t]] void *b_private; /* reserved for b_end_io */ struct list_head b_assoc_buffers; /* associated with another mapping */ - --[[linux-2.6.33/list_head]] struct address_space *b_assoc_map; /* mapping this buffer is associated with */ - --[[linux-2.6.33/address_space]] atomic_t b_count; /* users using this buffer_head */ - --[[linux-2.6.33/atomic_t]] }; *コメント [#i697079d]
