On Thu, Dec 24, 2015 at 01:49:24PM +0800, Chao Yu wrote: > Hi Jaegeuk, > > > -----Original Message----- > > From: Jaegeuk Kim [mailto:jaeg...@kernel.org] > > Sent: Thursday, December 24, 2015 10:15 AM > > To: linux-kernel@vger.kernel.org; linux-fsde...@vger.kernel.org; > > linux-f2fs-de...@lists.sourceforge.net > > Cc: Jaegeuk Kim > > Subject: [f2fs-dev] [PATCH 2/4] f2fs: return early when trying to read null > > nid > > > > If get_node_page() gets zero nid, we can return early without getting a > > wrong > > page. For example, get_dnode_of_data() can try to do that. > > Good catch! > > > > > Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org> > > --- > > fs/f2fs/node.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c > > index 341de5d..e17128d 100644 > > --- a/fs/f2fs/node.c > > +++ b/fs/f2fs/node.c > > @@ -1059,6 +1059,9 @@ struct page *get_node_page(struct f2fs_sb_info *sbi, > > pgoff_t nid) > > { > > struct page *page; > > int err; > > + > > + if (!nid) > > + return ERR_PTR(-ENOENT); > > How about expand to check upper and lower boundary: > > if (check_nid_range) > return ERR_PTR(-ENOENT);
It'd better to add f2fs_bug_on(check_nid_range()) after this. Cause check_nid_range() checks its nid as *unlikely*, but this case seems *likely*. Thanks, > > Thanks, > > > repeat: > > page = grab_cache_page(NODE_MAPPING(sbi), nid); > > if (!page) > > -- > > 2.5.4 (Apple Git-61) > > > > > > ------------------------------------------------------------------------------ > > _______________________________________________ > > Linux-f2fs-devel mailing list > > linux-f2fs-de...@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
