Hi Ritech, On Wed, Oct 30, 2019 at 03:43:10PM +0530, Ritesh Harjani wrote: > > > On 10/30/19 9:56 AM, Gao Xiang wrote: > > Similar to [1] [2], it seems a trivial cleanup since > > bio_alloc can handle memory allocation as mentioned in > > fs/direct-io.c (also see fs/block_dev.c, fs/buffer.c, ..) > > > > AFAIU, the reason is that, bio_alloc with __GFP_DIRECT_RECLAIM > flags guarantees bio allocation under some given restrictions, > as stated in fs/direct-io.c > So here it is ok to not check for NULL value from bio_alloc. > > I think we can update above info too in your commit msg. Ok, I will update commit msg as you suggested. > > > [1] https://lore.kernel.org/r/20191030035518.65477-1-gaoxiang25@xxxxxxxxxx > > [2] https://lore.kernel.org/r/20190830162812.GA10694@xxxxxxxxxxxxx > > Signed-off-by: Gao Xiang <gaoxiang25@xxxxxxxxxx> > > --- > > fs/ext4/page-io.c | 11 +++-------- > > fs/ext4/readpage.c | 2 -- > > 2 files changed, 3 insertions(+), 10 deletions(-) > > > > diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c > > index 12ceadef32c5..f1f7b6601780 100644 > > --- a/fs/ext4/page-io.c > > +++ b/fs/ext4/page-io.c > > @@ -358,14 +358,12 @@ void ext4_io_submit_init(struct ext4_io_submit *io, > > io->io_end = NULL; > > } > > > > -static int io_submit_init_bio(struct ext4_io_submit *io, > > - struct buffer_head *bh) > > +static void io_submit_init_bio(struct ext4_io_submit *io, > > + struct buffer_head *bh) > > { > > struct bio *bio; > > > > bio = bio_alloc(GFP_NOIO, BIO_MAX_PAGES); > > - if (!bio) > > - return -ENOMEM; > > bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9); > > bio_set_dev(bio, bh->b_bdev); > > bio->bi_end_io = ext4_end_bio; > > @@ -373,7 +371,6 @@ static int io_submit_init_bio(struct ext4_io_submit *io, > > io->io_bio = bio; > > io->io_next_block = bh->b_blocknr; > > wbc_init_bio(io->io_wbc, bio); > > - return 0; > > } > > > > static int io_submit_add_bh(struct ext4_io_submit *io, > > @@ -388,9 +385,7 @@ static int io_submit_add_bh(struct ext4_io_submit *io, > > ext4_io_submit(io); > > } > > if (io->io_bio == NULL) { > > - ret = io_submit_init_bio(io, bh); > > - if (ret) > > - return ret; > > + io_submit_init_bio(io, bh); > > io->io_bio->bi_write_hint = inode->i_write_hint; > > } > > ret = bio_add_page(io->io_bio, page, bh->b_size, bh_offset(bh)); > > > Also we can further simplify it like below. Please check. Got it, let me update the patch later. :-) Thanks for your suggestion. I will wait for a while and see if other opinions raise up... Thanks, Gao Xiang > > diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c > index f1f7b6601780..a3a2edeb3bbf 100644 > --- a/fs/ext4/page-io.c > +++ b/fs/ext4/page-io.c > @@ -373,7 +373,7 @@ static void io_submit_init_bio(struct ext4_io_submit > *io, > wbc_init_bio(io->io_wbc, bio); > } > > -static int io_submit_add_bh(struct ext4_io_submit *io, > +static void io_submit_add_bh(struct ext4_io_submit *io, > struct inode *inode, > struct page *page, > struct buffer_head *bh) > @@ -393,7 +393,6 @@ static int io_submit_add_bh(struct ext4_io_submit *io, > goto submit_and_retry; > wbc_account_cgroup_owner(io->io_wbc, page, bh->b_size); > io->io_next_block++; > - return 0; > } > > int ext4_bio_write_page(struct ext4_io_submit *io, > @@ -495,30 +494,23 @@ int ext4_bio_write_page(struct ext4_io_submit *io, > do { > if (!buffer_async_write(bh)) > continue; > - ret = io_submit_add_bh(io, inode, bounce_page ?: page, bh); > - if (ret) { > - /* > - * We only get here on ENOMEM. Not much else > - * we can do but mark the page as dirty, and > - * better luck next time. > - */ > - break; > - } > + io_submit_add_bh(io, inode, bounce_page ?: page, bh); > nr_submitted++; > clear_buffer_dirty(bh); > } while ((bh = bh->b_this_page) != head); > > - /* Error stopped previous loop? Clean up buffers... */ > - if (ret) { > - out: > - fscrypt_free_bounce_page(bounce_page); > - printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret); > - redirty_page_for_writepage(wbc, page); > - do { > - clear_buffer_async_write(bh); > - bh = bh->b_this_page; > - } while (bh != head); > - } > + goto unlock; > + > +out: > + fscrypt_free_bounce_page(bounce_page); > + printk_ratelimited(KERN_ERR "%s: ret = %d\n", __func__, ret); > + redirty_page_for_writepage(wbc, page); > + do { > + clear_buffer_async_write(bh); > + bh = bh->b_this_page; > + } while (bh != head); > + > +unlock: > unlock_page(page); > /* Nothing submitted - we have to end page writeback */ > if (!nr_submitted) > > > -ritesh >
