From: Gao Xiang <gaoxiang25@huawei.com>
To: Dan Carpenter <dan.carpenter@oracle.com>
Cc: miaoxie@huawei.com, xiang@kernel.org, linux-erofs@lists.ozlabs.org
Subject: Re: [bug report] staging: erofs: introduce erofs_grab_bio
Date: Wed, 28 Aug 2019 19:02:49 +0800 [thread overview]
Message-ID: <20190828110249.GA56298@architecture4> (raw)
In-Reply-To: <20190828105541.GA21320@mwanda>
Hi Dan,
On Wed, Aug 28, 2019 at 01:55:41PM +0300, Dan Carpenter wrote:
> Hello Gao Xiang,
>
> The patch 8be31270362b: "staging: erofs: introduce erofs_grab_bio"
> from Aug 21, 2018, leads to the following static checker warning:
>
> fs/erofs/zdata.c:1272 z_erofs_vle_submit_all()
> error: 'bio' dereferencing possible ERR_PTR()
>
> fs/erofs/zdata.c
> 1259 if (bio && force_submit) {
> 1260 submit_bio_retry:
> 1261 __submit_bio(bio, REQ_OP_READ, 0);
> 1262 bio = NULL;
> 1263 }
> 1264
> 1265 if (!bio) {
> 1266 bio = erofs_grab_bio(sb, first_index + i,
> 1267 BIO_MAX_PAGES, bi_private,
> 1268 z_erofs_vle_read_endio, true);
>
> This assumes erofs_grab_bio() can't fail. It returns ERR_PTR(-ENOMEM)
> on failure.
I think there is no problem at all as well.
The last argument of erofs_grab_bio is nofail, and here is "true".
415 static inline struct bio *erofs_grab_bio(struct super_block *sb,
416 erofs_blk_t blkaddr,
417 unsigned int nr_pages,
418 void *bi_private, bio_end_io_t endio,
419 bool nofail)
420 {
421 const gfp_t gfp = GFP_NOIO;
422 struct bio *bio;
423
424 do {
425 if (nr_pages == 1) {
426 bio = bio_alloc(gfp | (nofail ? __GFP_NOFAIL : 0), 1);
427 if (unlikely(!bio)) {
428 DBG_BUGON(nofail);
429 return ERR_PTR(-ENOMEM);
430 }
431 break;
432 }
433 bio = bio_alloc(gfp, nr_pages);
434 nr_pages /= 2;
435 } while (unlikely(!bio));
436
437 bio->bi_end_io = endio;
438 bio_set_dev(bio, sb->s_bdev);
439 bio->bi_iter.bi_sector = (sector_t)blkaddr << LOG_SECTORS_PER_BLOCK;
440 bio->bi_private = bi_private;
441 return bio;
442 }
You can see __GFP_NOFAIL is set, Am I missing something?
Thanks,
Gao Xiang
>
> 1269 ++nr_bios;
> 1270 }
> 1271
> 1272 err = bio_add_page(bio, page, PAGE_SIZE, 0);
> 1273 if (err < PAGE_SIZE)
> 1274 goto submit_bio_retry;
> 1275
> 1276 force_submit = false;
> 1277 last_index = first_index + i;
> 1278 skippage:
> 1279 if (++i < clusterpages)
> 1280 goto repeat;
>
> regards,
> dan carpenter
next prev parent reply other threads:[~2019-08-28 11:05 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-28 10:55 [bug report] staging: erofs: introduce erofs_grab_bio Dan Carpenter
2019-08-28 11:02 ` Gao Xiang [this message]
2019-08-28 11:36 ` Dan Carpenter
2019-08-28 11:40 ` Gao Xiang
2019-08-28 11:39 ` Gao Xiang
2019-08-28 12:11 ` Dan Carpenter
2019-08-28 12:22 ` Gao Xiang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190828110249.GA56298@architecture4 \
--to=gaoxiang25@huawei.com \
--cc=dan.carpenter@oracle.com \
--cc=linux-erofs@lists.ozlabs.org \
--cc=miaoxie@huawei.com \
--cc=xiang@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).