Messages in this thread | | | Date | Sun, 26 Mar 2023 21:47:14 +0800 | From | Chao Yu <> | Subject | Re: [f2fs-dev] [PATCH] f2fs: get out of a repeat loop when getting a locked data page |
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On 2023/3/24 5:39, Jaegeuk Kim wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=216050 > > Somehow we're getting a page which has a different mapping. > Let's avoid the infinite loop. > > Cc: <stable@vger.kernel.org> > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> > --- > fs/f2fs/data.c | 8 ++------ > 1 file changed, 2 insertions(+), 6 deletions(-) > > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index bf51e6e4eb64..80702c93e885 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -1329,18 +1329,14 @@ struct page *f2fs_get_lock_data_page(struct inode *inode, pgoff_t index, > { > struct address_space *mapping = inode->i_mapping; > struct page *page; > -repeat: > + > page = f2fs_get_read_data_page(inode, index, 0, for_write, NULL); > if (IS_ERR(page)) > return page; > > /* wait for read completion */ > lock_page(page); > - if (unlikely(page->mapping != mapping)) {
How about using such logic only for move_data_page() to limit affect for other paths?
Jaegeuk, any thoughts about why mapping is mismatch in between page's one and inode->i_mapping?
After several times code review, I didn't get any clue about why f2fs always get the different mapping in a loop.
Maybe we can loop MM guys to check whether below folio_file_page() may return page which has different mapping?
struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index, int fgp_flags, gfp_t gfp) { struct folio *folio;
folio = __filemap_get_folio(mapping, index, fgp_flags, gfp); if (IS_ERR(folio)) return NULL; return folio_file_page(folio, index); }
Thanks,
> - f2fs_put_page(page, 1); > - goto repeat; > - } > - if (unlikely(!PageUptodate(page))) { > + if (unlikely(page->mapping != mapping || !PageUptodate(page))) { > f2fs_put_page(page, 1); > return ERR_PTR(-EIO); > }
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