The patch titled
buffer_head: remove redundant test from wait_on_buffer
has been added to the -mm tree. Its filename is
buffer_head-remove-redundant-test-from-wait_on_buffer.patch
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------------------------------------------------------
Subject: buffer_head: remove redundant test from wait_on_buffer
From: Richard Kennedy <richard@xxxxxxxxxxxxxxx>
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 <richard@xxxxxxxxxxxxxxx>
Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx>
Cc: Jens Axboe <jens.axboe@xxxxxxxxxx>
Cc: Jeff Mahoney <jeffm@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/buffer_head.h | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)
diff -puN include/linux/buffer_head.h~buffer_head-remove-redundant-test-from-wait_on_buffer include/linux/buffer_head.h
--- a/include/linux/buffer_head.h~buffer_head-remove-redundant-test-from-wait_on_buffer
+++ a/include/linux/buffer_head.h
@@ -305,15 +305,10 @@ map_bh(struct buffer_head *bh, struct su
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)
{
might_sleep();
- if (buffer_locked(bh) || atomic_read(&bh->b_count) == 0)
+ if (buffer_locked(bh))
__wait_on_buffer(bh);
}
_
Patches currently in -mm which might be from richard@xxxxxxxxxxxxxxx are
linux-next.patch
buffer_head-remove-redundant-test-from-wait_on_buffer.patch
buffer_head-remove-redundant-test-from-wait_on_buffer-fix.patch
wait_on_buffer-remove-the-buffer_locked-test.patch
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