zfs/include/linux/blkdev_compat.h

436 lines
12 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (C) 2011 Lawrence Livermore National Security, LLC.
* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
* LLNL-CODE-403049.
*/
#ifndef _ZFS_BLKDEV_H
#define _ZFS_BLKDEV_H
#include <linux/blkdev.h>
#include <linux/elevator.h>
#ifndef HAVE_FMODE_T
typedef unsigned __bitwise__ fmode_t;
#endif /* HAVE_FMODE_T */
#ifndef HAVE_BLK_FETCH_REQUEST
static inline struct request *
blk_fetch_request(struct request_queue *q)
{
struct request *req;
req = elv_next_request(q);
if (req)
blkdev_dequeue_request(req);
return req;
}
#endif /* HAVE_BLK_FETCH_REQUEST */
#ifndef HAVE_BLK_REQUEUE_REQUEST
static inline void
blk_requeue_request(request_queue_t *q, struct request *req)
{
elv_requeue_request(q, req);
}
#endif /* HAVE_BLK_REQUEUE_REQUEST */
#ifndef HAVE_BLK_END_REQUEST
static inline bool
__blk_end_request(struct request *req, int error, unsigned int nr_bytes)
{
LIST_HEAD(list);
/*
* Request has already been dequeued but 2.6.18 version of
* end_request() unconditionally dequeues the request so we
* add it to a local list to prevent hitting the BUG_ON.
*/
list_add(&req->queuelist, &list);
/*
* The old API required the driver to end each segment and not
* the entire request. In our case we always need to end the
* entire request partial requests are not supported.
*/
req->hard_cur_sectors = nr_bytes >> 9;
end_request(req, ((error == 0) ? 1 : error));
return 0;
}
static inline bool
blk_end_request(struct request *req, int error, unsigned int nr_bytes)
{
struct request_queue *q = req->q;
bool rc;
spin_lock_irq(q->queue_lock);
rc = __blk_end_request(req, error, nr_bytes);
spin_unlock_irq(q->queue_lock);
return rc;
}
#else
# ifdef HAVE_BLK_END_REQUEST_GPL_ONLY
/*
* Define required to avoid conflicting 2.6.29 non-static prototype for a
* GPL-only version of the helper. As of 2.6.31 the helper is available
* to non-GPL modules and is not explicitly exported GPL-only.
*/
# define __blk_end_request __blk_end_request_x
# define blk_end_request blk_end_request_x
static inline bool
__blk_end_request_x(struct request *req, int error, unsigned int nr_bytes)
{
/*
* The old API required the driver to end each segment and not
* the entire request. In our case we always need to end the
* entire request partial requests are not supported.
*/
req->hard_cur_sectors = nr_bytes >> 9;
end_request(req, ((error == 0) ? 1 : error));
return 0;
}
static inline bool
blk_end_request_x(struct request *req, int error, unsigned int nr_bytes)
{
struct request_queue *q = req->q;
bool rc;
spin_lock_irq(q->queue_lock);
rc = __blk_end_request_x(req, error, nr_bytes);
spin_unlock_irq(q->queue_lock);
return rc;
}
# endif /* HAVE_BLK_END_REQUEST_GPL_ONLY */
#endif /* HAVE_BLK_END_REQUEST */
/*
* 2.6.36 API change,
* The blk_queue_flush() interface has replaced blk_queue_ordered()
* interface. However, while the old interface was available to all the
* new one is GPL-only. Thus if the GPL-only version is detected we
* implement our own trivial helper compatibility funcion. The hope is
* that long term this function will be opened up.
*/
#if defined(HAVE_BLK_QUEUE_FLUSH) && defined(HAVE_BLK_QUEUE_FLUSH_GPL_ONLY)
#define blk_queue_flush __blk_queue_flush
static inline void
__blk_queue_flush(struct request_queue *q, unsigned int flags)
{
q->flush_flags = flags & (REQ_FLUSH | REQ_FUA);
}
#endif /* HAVE_BLK_QUEUE_FLUSH && HAVE_BLK_QUEUE_FLUSH_GPL_ONLY */
#ifndef HAVE_BLK_RQ_POS
static inline sector_t
blk_rq_pos(struct request *req)
{
return req->sector;
}
#endif /* HAVE_BLK_RQ_POS */
#ifndef HAVE_BLK_RQ_SECTORS
static inline unsigned int
blk_rq_sectors(struct request *req)
{
return req->nr_sectors;
}
#endif /* HAVE_BLK_RQ_SECTORS */
#if !defined(HAVE_BLK_RQ_BYTES) || defined(HAVE_BLK_RQ_BYTES_GPL_ONLY)
/*
* Define required to avoid conflicting 2.6.29 non-static prototype for a
* GPL-only version of the helper. As of 2.6.31 the helper is available
* to non-GPL modules in the form of a static inline in the header.
*/
#define blk_rq_bytes __blk_rq_bytes
static inline unsigned int
__blk_rq_bytes(struct request *req)
{
return blk_rq_sectors(req) << 9;
}
#endif /* !HAVE_BLK_RQ_BYTES || HAVE_BLK_RQ_BYTES_GPL_ONLY */
/*
* Most of the blk_* macros were removed in 2.6.36. Ostensibly this was
* done to improve readability and allow easier grepping. However, from
* a portability stand point the macros are helpful. Therefore the needed
* macros are redefined here if they are missing from the kernel.
*/
#ifndef blk_fs_request
#define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
#endif
/*
* 2.6.27 API change,
* The blk_queue_stackable() queue flag was added in 2.6.27 to handle dm
* stacking drivers. Prior to this request stacking drivers were detected
* by checking (q->request_fn == NULL), for earlier kernels we revert to
* this legacy behavior.
*/
#ifndef blk_queue_stackable
#define blk_queue_stackable(q) ((q)->request_fn == NULL)
#endif
/*
* 2.6.34 API change,
* The blk_queue_max_hw_sectors() function replaces blk_queue_max_sectors().
*/
#ifndef HAVE_BLK_QUEUE_MAX_HW_SECTORS
#define blk_queue_max_hw_sectors __blk_queue_max_hw_sectors
static inline void
__blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors)
{
blk_queue_max_sectors(q, max_hw_sectors);
}
#endif
/*
* 2.6.34 API change,
* The blk_queue_max_segments() function consolidates
* blk_queue_max_hw_segments() and blk_queue_max_phys_segments().
*/
#ifndef HAVE_BLK_QUEUE_MAX_SEGMENTS
#define blk_queue_max_segments __blk_queue_max_segments
static inline void
__blk_queue_max_segments(struct request_queue *q, unsigned short max_segments)
{
blk_queue_max_phys_segments(q, max_segments);
blk_queue_max_hw_segments(q, max_segments);
}
#endif
/*
* 2.6.30 API change,
* The blk_queue_physical_block_size() function was introduced to
* indicate the smallest I/O the device can write without incurring
* a read-modify-write penalty. For older kernels this is a no-op.
*/
#ifndef HAVE_BLK_QUEUE_PHYSICAL_BLOCK_SIZE
#define blk_queue_physical_block_size(q, x) ((void)(0))
#endif
/*
* 2.6.30 API change,
* The blk_queue_io_opt() function was added to indicate the optimal
* I/O size for the device. For older kernels this is a no-op.
*/
#ifndef HAVE_BLK_QUEUE_IO_OPT
#define blk_queue_io_opt(q, x) ((void)(0))
#endif
#ifndef HAVE_GET_DISK_RO
static inline int
get_disk_ro(struct gendisk *disk)
{
int policy = 0;
if (disk->part[0])
policy = disk->part[0]->policy;
return policy;
}
#endif /* HAVE_GET_DISK_RO */
#ifndef HAVE_RQ_IS_SYNC
static inline bool
rq_is_sync(struct request *req)
{
return (req->flags & REQ_RW_SYNC);
}
#endif /* HAVE_RQ_IS_SYNC */
#ifndef HAVE_RQ_FOR_EACH_SEGMENT
struct req_iterator {
int i;
struct bio *bio;
};
# define for_each_bio(_bio) \
for (; _bio; _bio = _bio->bi_next)
# define __rq_for_each_bio(_bio, rq) \
if ((rq->bio)) \
for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
# define rq_for_each_segment(bvl, _rq, _iter) \
__rq_for_each_bio(_iter.bio, _rq) \
bio_for_each_segment(bvl, _iter.bio, _iter.i)
#endif /* HAVE_RQ_FOR_EACH_SEGMENT */
/*
* Portable helper for correctly setting the FAILFAST flags. The
* correct usage has changed 3 times from 2.6.12 to 2.6.38.
*/
static inline void
bio_set_flags_failfast(struct block_device *bdev, int *flags)
{
#ifdef CONFIG_BUG
/*
* Disable FAILFAST for loopback devices because of the
* following incorrect BUG_ON() in loop_make_request().
* This support is also disabled for md devices because the
* test suite layers md devices on top of loopback devices.
* This may be removed when the loopback driver is fixed.
*
* BUG_ON(!lo || (rw != READ && rw != WRITE));
*/
if ((MAJOR(bdev->bd_dev) == LOOP_MAJOR) ||
(MAJOR(bdev->bd_dev) == MD_MAJOR))
return;
#ifdef BLOCK_EXT_MAJOR
if (MAJOR(bdev->bd_dev) == BLOCK_EXT_MAJOR)
return;
#endif /* BLOCK_EXT_MAJOR */
#endif /* CONFIG_BUG */
#ifdef HAVE_BIO_RW_FAILFAST_DTD
/* BIO_RW_FAILFAST_* preferred interface from 2.6.28 - 2.6.35 */
*flags |=
((1 << BIO_RW_FAILFAST_DEV) |
(1 << BIO_RW_FAILFAST_TRANSPORT) |
(1 << BIO_RW_FAILFAST_DRIVER));
#else
# ifdef HAVE_BIO_RW_FAILFAST
/* BIO_RW_FAILFAST preferred interface from 2.6.12 - 2.6.27 */
*flags |= (1 << BIO_RW_FAILFAST);
# else
# ifdef HAVE_REQ_FAILFAST_MASK
/* REQ_FAILFAST_* preferred interface from 2.6.36 - 2.6.xx,
* the BIO_* and REQ_* flags were unified under REQ_* flags. */
*flags |= REQ_FAILFAST_MASK;
# endif /* HAVE_REQ_FAILFAST_MASK */
# endif /* HAVE_BIO_RW_FAILFAST */
#endif /* HAVE_BIO_RW_FAILFAST_DTD */
}
/*
* Maximum disk label length, it may be undefined for some kernels.
*/
#ifndef DISK_NAME_LEN
#define DISK_NAME_LEN 32
#endif /* DISK_NAME_LEN */
/*
* 2.6.24 API change,
* The bio_end_io() prototype changed slightly. These are helper
* macro's to ensure the prototype and return value are handled.
*/
#ifdef HAVE_2ARGS_BIO_END_IO_T
# define BIO_END_IO_PROTO(fn, x, y, z) static void fn(struct bio *x, int z)
# define BIO_END_IO_RETURN(rc) return
#else
# define BIO_END_IO_PROTO(fn, x, y, z) static int fn(struct bio *x, \
unsigned int y, int z)
# define BIO_END_IO_RETURN(rc) return rc
#endif /* HAVE_2ARGS_BIO_END_IO_T */
/*
* 2.6.38 - 2.6.x API,
* blkdev_get_by_path()
* blkdev_put()
*
* 2.6.28 - 2.6.37 API,
* open_bdev_exclusive()
* close_bdev_exclusive()
*
* 2.6.12 - 2.6.27 API,
* open_bdev_excl()
* close_bdev_excl()
*
* Used to exclusively open a block device from within the kernel.
*/
#if defined(HAVE_BLKDEV_GET_BY_PATH)
# define vdev_bdev_open(path, md, hld) blkdev_get_by_path(path, \
(md) | FMODE_EXCL, hld)
# define vdev_bdev_close(bdev, md) blkdev_put(bdev, (md) | FMODE_EXCL)
#elif defined(HAVE_OPEN_BDEV_EXCLUSIVE)
# define vdev_bdev_open(path, md, hld) open_bdev_exclusive(path, md, hld)
# define vdev_bdev_close(bdev, md) close_bdev_exclusive(bdev, md)
#else
# define vdev_bdev_open(path, md, hld) open_bdev_excl(path, md, hld)
# define vdev_bdev_close(bdev, md) close_bdev_excl(bdev)
#endif /* HAVE_BLKDEV_GET_BY_PATH | HAVE_OPEN_BDEV_EXCLUSIVE */
/*
* 2.6.22 API change
* The function invalidate_bdev() lost it's second argument because
* it was unused.
*/
#ifdef HAVE_1ARG_INVALIDATE_BDEV
# define vdev_bdev_invalidate(bdev) invalidate_bdev(bdev)
#else
# define vdev_bdev_invalidate(bdev) invalidate_bdev(bdev, 1)
#endif /* HAVE_1ARG_INVALIDATE_BDEV */
/*
* 2.6.30 API change
* Change to make it explicit there this is the logical block size.
*/
#ifdef HAVE_BDEV_LOGICAL_BLOCK_SIZE
# define vdev_bdev_block_size(bdev) bdev_logical_block_size(bdev)
#else
# define vdev_bdev_block_size(bdev) bdev_hardsect_size(bdev)
#endif
/*
* 2.6.37 API change
* The WRITE_FLUSH, WRITE_FUA, and WRITE_FLUSH_FUA flags have been
* introduced as a replacement for WRITE_BARRIER. This was done to
* allow richer semantics to be expressed to the block layer. It is
* the block layers responsibility to choose the correct way to
* implement these semantics.
*
* The existence of these flags implies that REQ_FLUSH an REQ_FUA are
* defined. Thus we can safely define VDEV_REQ_FLUSH and VDEV_REQ_FUA
* compatibility macros.
*/
#ifdef WRITE_FLUSH_FUA
# define VDEV_WRITE_FLUSH_FUA WRITE_FLUSH_FUA
# define VDEV_REQ_FLUSH REQ_FLUSH
# define VDEV_REQ_FUA REQ_FUA
#else
# define VDEV_WRITE_FLUSH_FUA WRITE_BARRIER
# define VDEV_REQ_FLUSH REQ_HARDBARRIER
# define VDEV_REQ_FUA REQ_HARDBARRIER
#endif
/*
* Default Linux IO Scheduler,
* Setting the scheduler to noop will allow the Linux IO scheduler to
* still perform front and back merging, while leaving the request
* ordering and prioritization to the ZFS IO scheduler.
*/
#define VDEV_SCHEDULER "noop"
#endif /* _ZFS_BLKDEV_H */