On 07/18, Chao Yu wrote:
> On 2019/7/18 11:12, Jaegeuk Kim wrote:
> > f2fs_allocate_data_block() invalidates old block address and enable new
> > block
> > address. Then, if we try to read old block by f2fs_submit_page_bio(), it
> > will
> > give WARN due to reading invalid blocks.
> >
> > Let's make the order sanely back.
>
> Hmm.. to avoid WARM, we may suffer one more memcpy, I suspect this can reduce
> online resize or foreground gc ioctl performance...
I worried about performance tho, more concern came to me that there may exist a
chance that other thread can allocate and write something in old block address.
>
> Can we just relief to use DATA_GENERIC_ENHANCE_READ for this case...?
We need to keep consistency for this api.
Thanks,
>
> >
> > Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
>
> Except performance, I'm okay with this change.
>
> Reviewed-by: Chao Yu <yuch...@huawei.com>
>
> Thanks,
>
> > ---
> > v2:
> > I was fixing the comments. :)
> >
> > fs/f2fs/gc.c | 70 +++++++++++++++++++++++++---------------------------
> > 1 file changed, 34 insertions(+), 36 deletions(-)
> >
> > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> > index 6691f526fa40..8974672db78f 100644
> > --- a/fs/f2fs/gc.c
> > +++ b/fs/f2fs/gc.c
> > @@ -796,6 +796,29 @@ static int move_data_block(struct inode *inode,
> > block_t bidx,
> > if (lfs_mode)
> > down_write(&fio.sbi->io_order_lock);
> >
> > + mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
> > + fio.old_blkaddr, false);
> > + if (!mpage)
> > + goto up_out;
> > +
> > + fio.encrypted_page = mpage;
> > +
> > + /* read source block in mpage */
> > + if (!PageUptodate(mpage)) {
> > + err = f2fs_submit_page_bio(&fio);
> > + if (err) {
> > + f2fs_put_page(mpage, 1);
> > + goto up_out;
> > + }
> > + lock_page(mpage);
> > + if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
> > + !PageUptodate(mpage))) {
> > + err = -EIO;
> > + f2fs_put_page(mpage, 1);
> > + goto up_out;
> > + }
> > + }
> > +
> > f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
> > &sum, CURSEG_COLD_DATA, NULL, false);
> >
> > @@ -803,44 +826,18 @@ static int move_data_block(struct inode *inode,
> > block_t bidx,
> > newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
> > if (!fio.encrypted_page) {
> > err = -ENOMEM;
> > - goto recover_block;
> > - }
> > -
> > - mpage = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
> > - fio.old_blkaddr, FGP_LOCK, GFP_NOFS);
> > - if (mpage) {
> > - bool updated = false;
> > -
> > - if (PageUptodate(mpage)) {
> > - memcpy(page_address(fio.encrypted_page),
> > - page_address(mpage), PAGE_SIZE);
> > - updated = true;
> > - }
> > f2fs_put_page(mpage, 1);
> > - invalidate_mapping_pages(META_MAPPING(fio.sbi),
> > - fio.old_blkaddr, fio.old_blkaddr);
> > - if (updated)
> > - goto write_page;
> > - }
> > -
> > - err = f2fs_submit_page_bio(&fio);
> > - if (err)
> > - goto put_page_out;
> > -
> > - /* write page */
> > - lock_page(fio.encrypted_page);
> > -
> > - if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) {
> > - err = -EIO;
> > - goto put_page_out;
> > - }
> > - if (unlikely(!PageUptodate(fio.encrypted_page))) {
> > - err = -EIO;
> > - goto put_page_out;
> > + goto recover_block;
> > }
> >
> > -write_page:
> > + /* write target block */
> > f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
> > + memcpy(page_address(fio.encrypted_page),
> > + page_address(mpage), PAGE_SIZE);
> > + f2fs_put_page(mpage, 1);
> > + invalidate_mapping_pages(META_MAPPING(fio.sbi),
> > + fio.old_blkaddr, fio.old_blkaddr);
> > +
> > set_page_dirty(fio.encrypted_page);
> > if (clear_page_dirty_for_io(fio.encrypted_page))
> > dec_page_count(fio.sbi, F2FS_DIRTY_META);
> > @@ -871,11 +868,12 @@ static int move_data_block(struct inode *inode,
> > block_t bidx,
> > put_page_out:
> > f2fs_put_page(fio.encrypted_page, 1);
> > recover_block:
> > - if (lfs_mode)
> > - up_write(&fio.sbi->io_order_lock);
> > if (err)
> > f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
> > true, true);
> > +up_out:
> > + if (lfs_mode)
> > + up_write(&fio.sbi->io_order_lock);
> > put_out:
> > f2fs_put_dnode(&dn);
> > out:
> >
>
>
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