From: Christoph Hellwig <hch@infradead.org>
To: Luis Chamberlain <mcgrof@kernel.org>
Cc: hch@infradead.org, djwong@kernel.org, dchinner@redhat.com,
kbusch@kernel.org, willy@infradead.org, hare@suse.de,
ritesh.list@gmail.com, rgoldwyn@suse.com, jack@suse.cz,
patches@lists.linux.dev, linux-xfs@vger.kernel.org,
linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
p.raghav@samsung.com, da.gomez@samsung.com,
rohan.puri@samsung.com, rpuri.linux@gmail.com, corbet@lwn.net,
jake@lwn.net
Subject: Re: [RFC 1/4] bdev: replace export of blockdev_superblock with BDEVFS_MAGIC
Date: Thu, 8 Jun 2023 06:53:46 -0700 [thread overview]
Message-ID: <ZIHdavOjpLpUC4cy@infradead.org> (raw)
In-Reply-To: <20230608032404.1887046-2-mcgrof@kernel.org>
On Wed, Jun 07, 2023 at 08:24:01PM -0700, Luis Chamberlain wrote:
> -extern struct super_block *blockdev_superblock;
> static inline bool sb_is_blkdev_sb(struct super_block *sb)
> {
> - return IS_ENABLED(CONFIG_BLOCK) && sb == blockdev_superblock;
> + return IS_ENABLED(CONFIG_BLOCK) && sb->s_magic == BDEVFS_MAGIC;
> }
So while I'd love to be able to make blockdev_superblock, I think
the existing code is the better idea here. BDEVFS_MAGIC can easily
end up in any other s_magic as it's a free-form field.
blockdev_superblock can't accidentally have the same address as a
random non-bdev sb.
next prev parent reply other threads:[~2023-06-08 13:53 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-08 3:24 [RFC 0/4] bdev: allow buffer-head & iomap aops to co-exist Luis Chamberlain
2023-06-08 3:24 ` [RFC 1/4] bdev: replace export of blockdev_superblock with BDEVFS_MAGIC Luis Chamberlain
2023-06-08 10:22 ` Jan Kara
2023-06-08 13:53 ` Christoph Hellwig [this message]
2023-06-08 3:24 ` [RFC 2/4] bdev: abstract inode lookup on blkdev_get_no_open() Luis Chamberlain
2023-06-08 3:24 ` [RFC 3/4] bdev: rename iomap aops Luis Chamberlain
2023-06-08 3:24 ` [RFC 4/4] bdev: extend bdev inode with it's own super_block Luis Chamberlain
2023-06-08 13:37 ` Matthew Wilcox
2023-06-08 13:50 ` Christoph Hellwig
2023-06-08 17:45 ` Luis Chamberlain
2023-06-09 4:20 ` Christoph Hellwig
2023-06-09 9:17 ` Luis Chamberlain
2023-06-08 13:50 ` Christoph Hellwig
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