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Subject[PATCH RFC] buffer_head: remove redundant test from wait_on_buffer
The comment suggests that when b_count equals zero it is calling
__wait_no_buffer to trigger some debug, but as there is no debug in
__wait_on_buffer the whole thing is redundant.

AFAICT from the git log this has been the case for at least 5 years, so
it seems safe just to remove this.

Signed-off-by: Richard Kennedy <>

This patch against 2.6.34-rc4
compiled & tested on x86_64


diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index 16ed028..4c62dd4 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -305,15 +305,10 @@ map_bh(struct buffer_head *bh, struct super_block *sb, sector_t block)
bh->b_size = sb->s_blocksize;

- * Calling wait_on_buffer() for a zero-ref buffer is illegal, so we call into
- * __wait_on_buffer() just to trip a debug check. Because debug code in inline
- * functions is bloaty.
- */
static inline void wait_on_buffer(struct buffer_head *bh)
- if (buffer_locked(bh) || atomic_read(&bh->b_count) == 0)
+ if (buffer_locked(bh))

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