2013-12-02 (월), 14:14 +0800, Chao Yu: > Hi Kim, > > > -----Original Message----- > > From: Jaegeuk Kim [mailto:jaegeuk....@samsung.com] > > Sent: Saturday, November 30, 2013 9:48 AM > > Cc: linux-fsde...@vger.kernel.org; linux-ker...@vger.kernel.org; > > linux-f2fs-devel@lists.sourceforge.net > > Subject: [f2fs-dev] [PATCH] f2fs: remove the own bi_private allocation > > > > Previously f2fs allocates its own bi_private data structure all the time > > even > > though we don't use it. But, can we remove this bi_private allocation? > > > > This patch removes such the additional bi_private allocation. > > > > 1. Retrieve f2fs_sb_info from its page->mapping->host->i_sb. > > - This removes the usecases of bi_private in end_io. > > > > 2. Use bi_private only when we really need it. > > - The bi_private is used only when the checkpoint procedure is conducted. > > - When conducting the checkpoint, f2fs submits a META_FLUSH bio to wait > > its bio > > completion. > > - Since we have no dependancies to remove bi_private now, let's just use > > bi_private pointer as the completion pointer. > > > > Signed-off-by: Jaegeuk Kim <jaegeuk....@samsung.com> > > --- > > fs/f2fs/segment.c | 43 ++++++++++++++++--------------------------- > > fs/f2fs/segment.h | 7 ------- > > 2 files changed, 16 insertions(+), 34 deletions(-) > > > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > > index 0387863..0db4027 100644 > > --- a/fs/f2fs/segment.c > > +++ b/fs/f2fs/segment.c > > @@ -791,7 +791,7 @@ static void f2fs_end_io_write(struct bio *bio, int err) > > { > > const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); > > struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; > > - struct bio_private *p = bio->bi_private; > > + struct f2fs_sb_info *sbi = F2FS_SB(bvec->bv_page->mapping->host->i_sb); > > I'm not sure whether bvec->bv_page->mapping will be set to NULL in the flow > where may not check WRITEBACK flag of page. Is it possible?
The mapping should be not NULL cause it is a writebacking page. Otherwise, it's a bug. Thanks, -- Jaegeuk Kim Samsung ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349351&iu=/4140/ostg.clktrk _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
