From: Andrew Morton <akpm@linux-foundation.org>
To: ocfs2-devel@oss.oracle.com
Subject: [Ocfs2-devel] [PATCH] ocfs2: don't evaluate buffer head to NULL managed by caller
Date: Thu, 29 Mar 2018 14:45:23 -0700 [thread overview]
Message-ID: <20180329144523.91722a7b35c8ad17d3f1375e@linux-foundation.org> (raw)
In-Reply-To: <1522289162-31693-1-git-send-email-ge.changwei@h3c.com>
On Thu, 29 Mar 2018 10:06:02 +0800 Changwei Ge <ge.changwei@h3c.com> wrote:
> ocfs2_read_blocks() is used to read several blocks from disk.
> Currently, the input argument *bhs* can be NULL or NOT. It depends on
> the caller's behavior. If the function fails in reading blocks from
> disk, the corresponding bh will be assigned to NULL and put.
>
> Obviously, above process for non-NULL input bh is not appropriate.
> Because the caller doesn't even know its bhs are put and re-assigned.
>
> If buffer head is managed by caller, ocfs2_read_blocks should not
> evaluate it to NULL. It will cause caller accessing illegal memory,
> thus crash.
(What about ocfs2_read_blocks_sync()?)
Passing non-NULL entries in bhs[] looks like a weird thing to do. Do
any callers actually do this? And of they do, do they actually care
about the alteration of bhs[] if the call failed?
next prev parent reply other threads:[~2018-03-29 21:45 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-29 2:06 [Ocfs2-devel] [PATCH] ocfs2: don't evaluate buffer head to NULL managed by caller Changwei Ge
2018-03-29 2:35 ` Gang He
2018-03-29 3:01 ` Changwei Ge
2018-03-29 3:21 ` Gang He
2018-03-29 6:25 ` Changwei Ge
2018-03-29 3:36 ` Larry Chen
2018-03-29 6:27 ` Changwei Ge
2018-03-29 9:50 ` piaojun
2018-03-29 10:32 ` Larry Chen
2018-03-29 12:04 ` Changwei Ge
2018-03-29 12:03 ` Changwei Ge
2018-03-29 21:45 ` Andrew Morton [this message]
2018-03-30 0:50 ` Changwei Ge
2018-03-30 1:26 ` Joseph Qi
2018-03-30 1:31 ` Changwei Ge
2018-03-30 2:03 ` Joseph Qi
2018-03-30 2:17 ` Changwei Ge
2018-03-30 2:37 ` Joseph Qi
2018-03-31 2:06 ` Changwei Ge
2018-03-30 2:16 ` piaojun
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