In this patch, I adjust the seqence of if-conditions.
It will assess the page->private situation.
First, we make sure the page->private is not null.
And then, we can do some with this page->private.
---
Signed-off-by: Liuwenyi <qingshenlwy@gmail.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Yan Zheng <zheng.yan@oracle.com>
Cc: Josef Bacik <jbacik@redhat.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: linux-btrfs@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
fs/btrfs/disk-io.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 009e3bd..a300dca 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1407,11 +1407,11 @@ static int bio_ready_for_csum(struct bio *bio)
bio_for_each_segment(bvec, bio, i) {
page = bvec->bv_page;
- if (page->private == EXTENT_PAGE_PRIVATE) {
+ if (!page->private) {
length += bvec->bv_len;
continue;
}
- if (!page->private) {
+ if (page->private == EXTENT_PAGE_PRIVATE) {
length += bvec->bv_len;
continue;
}
--
1.6.6
---
Best Regards,
Liuwenyi
2010-01-277
2010/1/27 Liuwenyi <qingshenlwy@gmail.com>:> In this patch, I adjust the seqence of if-conditions. > It will assess the page->private situation. > First, we make sure the page->private is not null. > And then, we can do some with this page->private. > > --- > Signed-off-by: Liuwenyi <qingshenlwy@gmail.com> > Cc: Chris Mason <chris.mason@oracle.com> > Cc: Yan Zheng <zheng.yan@oracle.com> > Cc: Josef Bacik <jbacik@redhat.com> > Cc: Jens Axboe <jens.axboe@oracle.com> > Cc: linux-btrfs@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > > --- > fs/btrfs/disk-io.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > index 009e3bd..a300dca 100644 > --- a/fs/btrfs/disk-io.c > +++ b/fs/btrfs/disk-io.c > @@ -1407,11 +1407,11 @@ static int bio_ready_for_csum(struct bio *bio) > > bio_for_each_segment(bvec, bio, i) { > page = bvec->bv_page; > - if (page->private == EXTENT_PAGE_PRIVATE) { > + if (!page->private) { > length += bvec->bv_len; > continue; > } > - if (!page->private) { > + if (page->private == EXTENT_PAGE_PRIVATE) { > length += bvec->bv_len; > continue; > } > --Why do you want to do this? The code is perfect safe even page->private is NULL. Furthermore, your patch is malformed. Yan, Zheng
于 2010年01月27日 16:00, Yan, Zheng 写道:> 2010/1/27 Liuwenyi<qingshenlwy@gmail.com>: > >> In this patch, I adjust the seqence of if-conditions. >> It will assess the page->private situation. >> First, we make sure the page->private is not null. >> And then, we can do some with this page->private. >> >> --- >> Signed-off-by: Liuwenyi<qingshenlwy@gmail.com> >> Cc: Chris Mason<chris.mason@oracle.com> >> Cc: Yan Zheng<zheng.yan@oracle.com> >> Cc: Josef Bacik<jbacik@redhat.com> >> Cc: Jens Axboe<jens.axboe@oracle.com> >> Cc: linux-btrfs@vger.kernel.org >> Cc: linux-kernel@vger.kernel.org >> >> --- >> fs/btrfs/disk-io.c | 4 ++-- >> 1 files changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c >> index 009e3bd..a300dca 100644 >> --- a/fs/btrfs/disk-io.c >> +++ b/fs/btrfs/disk-io.c >> @@ -1407,11 +1407,11 @@ static int bio_ready_for_csum(struct bio *bio) >> >> bio_for_each_segment(bvec, bio, i) { >> page = bvec->bv_page; >> - if (page->private == EXTENT_PAGE_PRIVATE) { >> + if (!page->private) { >> length += bvec->bv_len; >> continue; >> } >> - if (!page->private) { >> + if (page->private == EXTENT_PAGE_PRIVATE) { >> length += bvec->bv_len; >> continue; >> } >> -- >> > Why do you want to do this? The code is perfect safe even > page->private is NULL. Furthermore, your patch is malformed. > > Yan, Zheng >Yes, I agree with you, this code is safe. But I think we should check whether the pointer is available first. It is unnecessary judge the "(page->private == EXTENT_PAGE_PRIVATE)" while page->private is null. --- Best Regards, Liuwenyi 2010-1-27