Miao Xie
2010-Jul-29 08:32 UTC
[PATCH 7/7] btrfs: fix a wrong error check in add_ra_bio_pages()
From: Liu Bo <liubo2009@cn.fujitsu.com>
Only when a page is not found by page_index, we''ll go to the error
check.
Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
---
fs/btrfs/compression.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index cb3877c..8458840 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -467,7 +467,7 @@ static noinline int add_ra_bio_pages(struct inode *inode,
rcu_read_lock();
page = radix_tree_lookup(&mapping->page_tree, page_index);
rcu_read_unlock();
- if (page) {
+ if (!page) {
check_misses:
misses++;
if (misses > 4)
--
1.7.0.1
Yan, Zheng
2010-Jul-29 10:38 UTC
Re: [PATCH 7/7] btrfs: fix a wrong error check in add_ra_bio_pages()
2010/7/29 Miao Xie <miaox@cn.fujitsu.com>:> From: Liu Bo <liubo2009@cn.fujitsu.com> > > Only when a page is not found by page_index, we''ll go to the error check. > > Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> > Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> > --- > fs/btrfs/compression.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c > index cb3877c..8458840 100644 > --- a/fs/btrfs/compression.c > +++ b/fs/btrfs/compression.c > @@ -467,7 +467,7 @@ static noinline int add_ra_bio_pages(struct inode *inode, > rcu_read_lock(); > page = radix_tree_lookup(&mapping->page_tree, page_index); > rcu_read_unlock(); > - if (page) { > + if (!page) { > check_misses: > misses++; > if (misses > 4)This patch is wrong. The word "miss" here means "miss for read-ahead because the page is already in the page cache" Yan, Zheng
Miao Xie
2010-Jul-29 10:47 UTC
Re: [PATCH 7/7] btrfs: fix a wrong error check in add_ra_bio_pages()
On Thu, 29 Jul 2010 18:38:39 +0800, Yan, Zheng wrote:> 2010/7/29 Miao Xie<miaox@cn.fujitsu.com>: >> From: Liu Bo<liubo2009@cn.fujitsu.com> >> >> Only when a page is not found by page_index, we''ll go to the error check. >> >> Signed-off-by: Liu Bo<liubo2009@cn.fujitsu.com> >> Signed-off-by: Miao Xie<miaox@cn.fujitsu.com> >> --- >> fs/btrfs/compression.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c >> index cb3877c..8458840 100644 >> --- a/fs/btrfs/compression.c >> +++ b/fs/btrfs/compression.c >> @@ -467,7 +467,7 @@ static noinline int add_ra_bio_pages(struct inode *inode, >> rcu_read_lock(); >> page = radix_tree_lookup(&mapping->page_tree, page_index); >> rcu_read_unlock(); >> - if (page) { >> + if (!page) { >> check_misses: >> misses++; >> if (misses> 4) > > This patch is wrong. The word "miss" here means "miss for read-ahead because > the page is already in the page cache"Oh, my mistake. Sorry! Please ignore this patch. Thanks for your review! How about the others? Miao> > Yan, Zheng > >