[PATCH 1/4] Add buffer head related helper functions
From: Aneesh Kumar K.V <hidden>
Date: 2007-11-15 12:11:32
Subsystem:
the rest · Maintainer:
Linus Torvalds
Add buffer head related helper function bh_uptodate_or_lock and bh_submit_read which can be used by file system Signed-off-by: Aneesh Kumar K.V <redacted> --- include/linux/buffer_head.h | 29 +++++++++++++++++++++++++++++ 1 files changed, 29 insertions(+), 0 deletions(-)
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index da0d83f..82cc9ef 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h@@ -327,6 +327,35 @@ static inline void lock_buffer(struct buffer_head *bh) extern int __set_page_dirty_buffers(struct page *page); +/* Return true if the buffer is up-to-date. + * Return false, with the buffer locked, if not. + */ +static inline int bh_uptodate_or_lock(struct buffer_head *bh) +{ + if (!buffer_uptodate(bh)) { + lock_buffer(bh); + if (!buffer_uptodate(bh)) + return 0; + unlock_buffer(bh); + } + return 1; +} +/* + * Submit a locked buffer for reading, + * return a negative error and release + * the buffer if failed. + */ +static inline int bh_submit_read(struct buffer_head *bh) +{ + get_bh(bh); + bh->b_end_io = end_buffer_read_sync; + submit_bh(READ, bh); + wait_on_buffer(bh); + if (buffer_uptodate(bh)) + return 0; + brelse(bh); + return -EIO; +} #else /* CONFIG_BLOCK */ static inline void buffer_init(void) {}
--
1.5.3.5.652.gf192c-dirty