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From: Dan Carpenter <dan.carpenter@oracle.com>
To: walter harms <wharms@bfs.de>
Cc: kernel-janitors@vger.kernel.org, linux-mtd@lists.infradead.org
Subject: Re: [patch] mtd: use correct error codes in debugfs_create()
Date: Mon, 22 Jul 2013 12:47:12 +0000	[thread overview]
Message-ID: <20130722124712.GG5636@mwanda> (raw)
In-Reply-To: <51ECE488.1050307@bfs.de>

The debugfs API is a bit confusing initialy but it's straight
foward to use.  You call:

	dfs_rootdir = debugfs_create_dir(...);

If it returns NULL then you return an error code.  If debugfs is
not enabled then it returns ERR_PTR(-ENODEV) but you don't normally
need to test for it.  After all later when you call:

	debugfs_create_file("wear_report", S_IRUSR,
			    dfs_rootdir, dev, &dfs_fops);

That function is just a no-op because debugfs is disabled.

The problem here is that we test for IS_ERR_OR_NULL() instead of
just if (!dfs_rootdir) which is wrong.  Also if we do hit an error
we return success because the true false bit are reversed.

regards,
dan carpenter
> 

WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: walter harms <wharms@bfs.de>
Cc: kernel-janitors@vger.kernel.org, linux-mtd@lists.infradead.org
Subject: Re: [patch] mtd: use correct error codes in debugfs_create()
Date: Mon, 22 Jul 2013 15:47:12 +0300	[thread overview]
Message-ID: <20130722124712.GG5636@mwanda> (raw)
In-Reply-To: <51ECE488.1050307@bfs.de>

The debugfs API is a bit confusing initialy but it's straight
foward to use.  You call:

	dfs_rootdir = debugfs_create_dir(...);

If it returns NULL then you return an error code.  If debugfs is
not enabled then it returns ERR_PTR(-ENODEV) but you don't normally
need to test for it.  After all later when you call:

	debugfs_create_file("wear_report", S_IRUSR,
			    dfs_rootdir, dev, &dfs_fops);

That function is just a no-op because debugfs is disabled.

The problem here is that we test for IS_ERR_OR_NULL() instead of
just if (!dfs_rootdir) which is wrong.  Also if we do hit an error
we return success because the true false bit are reversed.

regards,
dan carpenter
> 

  reply	other threads:[~2013-07-22 12:47 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-07-19  5:49 [patch] mtd: use correct error codes in debugfs_create() Dan Carpenter
2013-07-19  5:49 ` Dan Carpenter
2013-07-22  5:56 ` Dan Carpenter
2013-07-22  5:56   ` Dan Carpenter
2013-07-22  7:51   ` walter harms
2013-07-22  7:51     ` walter harms
2013-07-22 12:47     ` Dan Carpenter [this message]
2013-07-22 12:47       ` Dan Carpenter
2013-07-22 20:43 ` [patch v2] mtd: tiny debugfs related fixes Dan Carpenter
2013-07-22 20:43   ` Dan Carpenter

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