Messages in this thread | | | Date | Wed, 29 Jan 2020 11:46:09 +1100 | From | Dave Chinner <> | Subject | Re: [PATCH 06/12] btrfs: Convert from readpages to readahead |
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On Fri, Jan 24, 2020 at 05:35:47PM -0800, Matthew Wilcox wrote: > From: "Matthew Wilcox (Oracle)" <willy@infradead.org> > > Use the new readahead operation in btrfs > > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > Cc: linux-btrfs@vger.kernel.org > --- > fs/btrfs/extent_io.c | 15 ++++----------- > fs/btrfs/extent_io.h | 2 +- > fs/btrfs/inode.c | 18 +++++++++--------- > 3 files changed, 14 insertions(+), 21 deletions(-) > > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c > index 2f4802f405a2..b1e2acbec165 100644 > --- a/fs/btrfs/extent_io.c > +++ b/fs/btrfs/extent_io.c > @@ -4283,7 +4283,7 @@ int extent_writepages(struct address_space *mapping, > return ret; > } > > -int extent_readpages(struct address_space *mapping, struct list_head *pages, > +unsigned extent_readahead(struct address_space *mapping, pgoff_t start, > unsigned nr_pages) > { > struct bio *bio = NULL; > @@ -4294,20 +4294,13 @@ int extent_readpages(struct address_space *mapping, struct list_head *pages, > int nr = 0; > u64 prev_em_start = (u64)-1; > > - while (!list_empty(pages)) { > + while (nr_pages) { > u64 contig_end = 0; > > - for (nr = 0; nr < ARRAY_SIZE(pagepool) && !list_empty(pages);) { > - struct page *page = lru_to_page(pages); > + for (nr = 0; nr < ARRAY_SIZE(pagepool) && nr_pages--;) {
What is stopping nr_pages from going negative here, and then looping forever on the outer nr_pages loop? Perhaps "while(nr_pages > 0) {" would be better there?
-Dave. -- Dave Chinner david@fromorbit.com
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