Re: [f2fs-dev] [PATCH 1/4] f2fs: propagate error given by f2fs_find_entry

From: Jaegeuk Kim
Date: Sun May 29 2016 - 22:39:09 EST


On Fri, May 27, 2016 at 12:48:48PM +0800, He YunLei wrote:
> On 2016/5/27 8:25, Jaegeuk Kim wrote:
> >If we get ENOMEM or EIO in f2fs_find_entry, we should stop right away.
> >Otherwise, for example, we can get duplicate directory entry by ->chash and
> >->clevel.
> >
> >Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
> >---
> > fs/f2fs/dir.c | 23 ++++++++++++++++-------
> > fs/f2fs/inline.c | 4 +++-
> > fs/f2fs/namei.c | 5 +++++
> > 3 files changed, 24 insertions(+), 8 deletions(-)
> >
> >diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
> >index 24d1308..ae37543 100644
> >--- a/fs/f2fs/dir.c
> >+++ b/fs/f2fs/dir.c
> >@@ -185,8 +185,13 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir,
> > /* no need to allocate new dentry pages to all the indices */
> > dentry_page = find_data_page(dir, bidx);
> > if (IS_ERR(dentry_page)) {
> >- room = true;
> >- continue;
> >+ if (PTR_ERR(dentry_page) == -ENOENT) {
> >+ room = true;
> >+ continue;
> >+ } else {
> >+ *res_page = dentry_page;
> >+ break;
> >+ }
> > }
> >
> > de = find_in_block(dentry_page, fname, namehash, &max_slots,
> >@@ -223,19 +228,22 @@ struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
> > struct fscrypt_name fname;
> > int err;
> >
> >- *res_page = NULL;
> >-
> > err = fscrypt_setup_filename(dir, child, 1, &fname);
> >- if (err)
> >+ if (err) {
> >+ *res_page = ERR_PTR(-ENOMEM);
> > return NULL;
> >+ }
> >
> > if (f2fs_has_inline_dentry(dir)) {
> >+ *res_page = NULL;
> > de = find_in_inline_dir(dir, &fname, res_page);
> > goto out;
> > }
> >
> >- if (npages == 0)
> >+ if (npages == 0) {
> >+ *res_page = NULL;
> > goto out;
> >+ }
> >
> > max_depth = F2FS_I(dir)->i_current_depth;
> > if (unlikely(max_depth > MAX_DIR_HASH_DEPTH)) {
> >@@ -247,8 +255,9 @@ struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
> > }
> >
> > for (level = 0; level < max_depth; level++) {
> >+ *res_page = NULL;
> > de = find_in_level(dir, level, &fname, res_page);
> >- if (de)
> >+ if (de || IS_ERR(*res_page))
> > break;
> > }
>
> Hi, kim
> Here, we return NULL for the error of find_data_page, it means
> the file looked up is not exist to vfs, but may be the file has already exist
> behind the block read error. So maybe we 'd better reported the error to vfs.
>

How about this? :)