Linux NFS development
 help / color / mirror / Atom feed
From: Dan Carpenter <error27@gmail.com>
To: trond.myklebust@hammerspace.com
Cc: linux-nfs@vger.kernel.org
Subject: [bug report] NFS: Convert buffered writes to use folios
Date: Wed, 22 Feb 2023 17:02:18 +0300	[thread overview]
Message-ID: <Y/YgahwOk4DL217a@kili> (raw)

Hello Trond Myklebust,

This is a semi-automatic email about new static checker warnings.

The patch 0c493b5cf16e: "NFS: Convert buffered writes to use folios" 
from Jan 19, 2023, leads to the following Smatch complaint:

    fs/nfs/write.c:793 nfs_inode_remove_request()
    warn: variable dereferenced before check 'folio' (see line 790)

fs/nfs/write.c
   789			struct folio *folio = nfs_page_to_folio(req->wb_head);
   790			struct address_space *mapping = folio_file_mapping(folio);
                                                                           ^^^^^
Patch adds dereference

   791	
   792			spin_lock(&mapping->private_lock);
   793			if (likely(folio && !folio_test_swapcache(folio))) {
                                   ^^^^^
Patch adds a check (too late).

   794				folio->private = NULL;
   795				folio_clear_private(folio);

regards,
dan carpenter

                 reply	other threads:[~2023-02-23  4:57 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

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=Y/YgahwOk4DL217a@kili \
    --to=error27@gmail.com \
    --cc=linux-nfs@vger.kernel.org \
    --cc=trond.myklebust@hammerspace.com \
    /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