From: Christoph Hellwig <hch@lst.de>
To: Arnd Bergmann <arnd@arndb.de>
Cc: linux-kernel@vger.kernel.org,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Jani Nikula <jani.nikula@intel.com>,
Randy Dunlap <rdunlap@infradead.org>,
"Darrick J. Wong" <darrick.wong@oracle.com>,
Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
Hannes Reinecke <hare@suse.com>, Omar Sandoval <osandov@fb.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>
Subject: Re: [PATCH] [v2] blkdev: always export SECTOR_SHIFT
Date: Fri, 19 Jul 2019 14:13:37 +0200 [thread overview]
Message-ID: <20190719121336.GB28960@lst.de> (raw)
In-Reply-To: <20190719113139.4005262-1-arnd@arndb.de>
> +/*
> + * The basic unit of block I/O is a sector. It is used in a number of contexts
> + * in Linux (blk, bio, genhd). The size of one sector is 512 = 2**9
> + * bytes. Variables of type sector_t represent an offset or size that is a
> + * multiple of 512 bytes. Hence these two constants.
> + */
> +#ifndef SECTOR_SHIFT
> +#define SECTOR_SHIFT 9
> +#endif
> +#ifndef SECTOR_SIZE
> +#define SECTOR_SIZE (1 << SECTOR_SHIFT)
> +#endif
While we're at it we really should drop the ifndefs.
Otherwise looks good.
In fact given that sector_t is in linux/types.h I wonder if these
should just move there.
next prev parent reply other threads:[~2019-07-19 12:13 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-19 11:31 Arnd Bergmann
2019-07-19 12:13 ` Christoph Hellwig [this message]
2019-07-19 13:14 ` Arnd Bergmann
2019-07-19 13:28 ` Arnd Bergmann
2019-07-19 12:47 ` Masahiro Yamada
2019-07-19 13:15 ` Arnd Bergmann
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