From: Nicolas Pitre <nicolas.pitre@linaro.org>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
linux-embedded@vger.kernel.org, linux-kernel@vger.kernel.org,
Chris Brandt <Chris.Brandt@renesas.com>
Subject: Re: [PATCH v6 1/4] cramfs: direct memory access support
Date: Fri, 13 Oct 2017 13:39:13 -0400 (EDT) [thread overview]
Message-ID: <nycvar.YSQ.7.76.1710131332360.1718@knanqh.ubzr> (raw)
In-Reply-To: <20171013172934.GG21978@ZenIV.linux.org.uk>
On Fri, 13 Oct 2017, Al Viro wrote:
> On Thu, Oct 12, 2017 at 02:16:10AM -0400, Nicolas Pitre wrote:
>
> > static void cramfs_kill_sb(struct super_block *sb)
> > {
> > struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
> >
> > - kill_block_super(sb);
> > + if (IS_ENABLED(CCONFIG_CRAMFS_MTD)) {
> > + if (sbi->mtd_point_size)
> > + mtd_unpoint(sb->s_mtd, 0, sbi->mtd_point_size);
> > + if (sb->s_mtd)
> > + kill_mtd_super(sb);
>
> ...
>
> > + mtd_unpoint(sb->s_mtd, 0, PAGE_SIZE);
> > + err = mtd_point(sb->s_mtd, 0, sbi->size, &sbi->mtd_point_size,
> > + &sbi->linear_virt_addr, &sbi->linear_phys_addr);
> > + if (err || sbi->mtd_point_size != sbi->size) {
>
> What happens if that mtd_point() fails? Note that ->kill_sb() will be
> called anyway and ->mtd_point_size is going to be non-zero here...
mtd_point() always clears sbi->mtd_point_size first thing upon entry
even before it has a chance to fail. So it it fails then
sbi->mtd_point_size will be zero and ->kill_sb() will skip the unpoint
call.
Nicolas
WARNING: multiple messages have this Message-ID (diff)
From: Nicolas Pitre <nicolas.pitre@linaro.org>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>,
linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
linux-embedded@vger.kernel.org, linux-kernel@vger.kernel.org,
Chris Brandt <Chris.Brandt@renesas.com>
Subject: Re: [PATCH v6 1/4] cramfs: direct memory access support
Date: Fri, 13 Oct 2017 13:39:13 -0400 (EDT) [thread overview]
Message-ID: <nycvar.YSQ.7.76.1710131332360.1718@knanqh.ubzr> (raw)
In-Reply-To: <20171013172934.GG21978@ZenIV.linux.org.uk>
On Fri, 13 Oct 2017, Al Viro wrote:
> On Thu, Oct 12, 2017 at 02:16:10AM -0400, Nicolas Pitre wrote:
>
> > static void cramfs_kill_sb(struct super_block *sb)
> > {
> > struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
> >
> > - kill_block_super(sb);
> > + if (IS_ENABLED(CCONFIG_CRAMFS_MTD)) {
> > + if (sbi->mtd_point_size)
> > + mtd_unpoint(sb->s_mtd, 0, sbi->mtd_point_size);
> > + if (sb->s_mtd)
> > + kill_mtd_super(sb);
>
> ...
>
> > + mtd_unpoint(sb->s_mtd, 0, PAGE_SIZE);
> > + err = mtd_point(sb->s_mtd, 0, sbi->size, &sbi->mtd_point_size,
> > + &sbi->linear_virt_addr, &sbi->linear_phys_addr);
> > + if (err || sbi->mtd_point_size != sbi->size) {
>
> What happens if that mtd_point() fails? Note that ->kill_sb() will be
> called anyway and ->mtd_point_size is going to be non-zero here...
mtd_point() always clears sbi->mtd_point_size first thing upon entry
even before it has a chance to fail. So it it fails then
sbi->mtd_point_size will be zero and ->kill_sb() will skip the unpoint
call.
Nicolas
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next prev parent reply other threads:[~2017-10-13 17:39 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-12 6:16 [PATCH v6 0/4] cramfs refresh for embedded usage Nicolas Pitre
2017-10-12 6:16 ` Nicolas Pitre
2017-10-12 6:16 ` [PATCH v6 1/4] cramfs: direct memory access support Nicolas Pitre
2017-10-12 6:16 ` Nicolas Pitre
2017-10-12 17:03 ` Chris Brandt
2017-10-12 17:03 ` Chris Brandt
2017-10-13 1:20 ` Nicolas Pitre
2017-10-13 1:20 ` Nicolas Pitre
2017-10-13 7:30 ` Christoph Hellwig
2017-10-13 7:30 ` Christoph Hellwig
2017-10-13 17:29 ` Al Viro
2017-10-13 17:29 ` Al Viro
2017-10-13 17:39 ` Nicolas Pitre [this message]
2017-10-13 17:39 ` Nicolas Pitre
2017-10-13 17:52 ` Al Viro
2017-10-13 17:52 ` Al Viro
2017-10-13 18:18 ` Nicolas Pitre
2017-10-13 18:18 ` Nicolas Pitre
2017-10-13 20:09 ` Nicolas Pitre
2017-10-13 20:09 ` Nicolas Pitre
2017-10-14 0:31 ` Al Viro
2017-10-14 0:31 ` Al Viro
2017-10-14 2:25 ` Nicolas Pitre
2017-10-14 2:25 ` Nicolas Pitre
2017-10-14 2:37 ` Nicolas Pitre
2017-10-14 2:37 ` Nicolas Pitre
2017-10-12 6:16 ` [PATCH v6 2/4] cramfs: implement uncompressed and arbitrary data block positioning Nicolas Pitre
2017-10-12 6:16 ` Nicolas Pitre
2017-10-12 6:16 ` [PATCH v6 3/4] cramfs: add mmap support Nicolas Pitre
2017-10-12 6:16 ` Nicolas Pitre
2017-10-13 7:31 ` Christoph Hellwig
2017-10-13 7:31 ` Christoph Hellwig
2017-10-12 6:16 ` [PATCH v6 4/4] cramfs: rehabilitate it Nicolas Pitre
2017-10-12 6:16 ` Nicolas Pitre
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