347 lines
11 KiB
C
347 lines
11 KiB
C
/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License (the "License").
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* You may not use this file except in compliance with the License.
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*
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* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
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* or http://www.opensolaris.org/os/licensing.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
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* If applicable, add the following below this CDDL HEADER, with the
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* fields enclosed by brackets "[]" replaced with your own identifying
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* information: Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*/
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/*
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* Copyright (C) 2011 Lawrence Livermore National Security, LLC.
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* Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
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* Written by Brian Behlendorf <behlendorf1@llnl.gov>.
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* LLNL-CODE-403049.
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*/
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#ifndef _ZFS_BLKDEV_H
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#define _ZFS_BLKDEV_H
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#include <linux/blkdev.h>
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#include <linux/elevator.h>
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#ifndef HAVE_FMODE_T
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typedef unsigned __bitwise__ fmode_t;
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#endif /* HAVE_FMODE_T */
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/*
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* 2.6.36 API change,
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* The blk_queue_flush() interface has replaced blk_queue_ordered()
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* interface. However, while the old interface was available to all the
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* new one is GPL-only. Thus if the GPL-only version is detected we
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* implement our own trivial helper compatibility funcion. The hope is
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* that long term this function will be opened up.
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*/
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#if defined(HAVE_BLK_QUEUE_FLUSH) && defined(HAVE_BLK_QUEUE_FLUSH_GPL_ONLY)
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#define blk_queue_flush __blk_queue_flush
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static inline void
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__blk_queue_flush(struct request_queue *q, unsigned int flags)
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{
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q->flush_flags = flags & (REQ_FLUSH | REQ_FUA);
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}
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#endif /* HAVE_BLK_QUEUE_FLUSH && HAVE_BLK_QUEUE_FLUSH_GPL_ONLY */
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/*
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* Most of the blk_* macros were removed in 2.6.36. Ostensibly this was
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* done to improve readability and allow easier grepping. However, from
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* a portability stand point the macros are helpful. Therefore the needed
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* macros are redefined here if they are missing from the kernel.
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*/
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#ifndef blk_fs_request
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#define blk_fs_request(rq) ((rq)->cmd_type == REQ_TYPE_FS)
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#endif
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/*
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* 2.6.27 API change,
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* The blk_queue_stackable() queue flag was added in 2.6.27 to handle dm
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* stacking drivers. Prior to this request stacking drivers were detected
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* by checking (q->request_fn == NULL), for earlier kernels we revert to
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* this legacy behavior.
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*/
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#ifndef blk_queue_stackable
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#define blk_queue_stackable(q) ((q)->request_fn == NULL)
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#endif
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/*
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* 2.6.34 API change,
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* The blk_queue_max_hw_sectors() function replaces blk_queue_max_sectors().
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*/
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#ifndef HAVE_BLK_QUEUE_MAX_HW_SECTORS
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#define blk_queue_max_hw_sectors __blk_queue_max_hw_sectors
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static inline void
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__blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_sectors)
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{
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blk_queue_max_sectors(q, max_hw_sectors);
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}
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#endif
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/*
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* 2.6.34 API change,
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* The blk_queue_max_segments() function consolidates
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* blk_queue_max_hw_segments() and blk_queue_max_phys_segments().
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*/
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#ifndef HAVE_BLK_QUEUE_MAX_SEGMENTS
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#define blk_queue_max_segments __blk_queue_max_segments
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static inline void
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__blk_queue_max_segments(struct request_queue *q, unsigned short max_segments)
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{
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blk_queue_max_phys_segments(q, max_segments);
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blk_queue_max_hw_segments(q, max_segments);
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}
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#endif
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#ifndef HAVE_GET_DISK_RO
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static inline int
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get_disk_ro(struct gendisk *disk)
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{
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int policy = 0;
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if (disk->part[0])
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policy = disk->part[0]->policy;
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return (policy);
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}
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#endif /* HAVE_GET_DISK_RO */
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#ifdef HAVE_BIO_BVEC_ITER
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#define BIO_BI_SECTOR(bio) (bio)->bi_iter.bi_sector
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#define BIO_BI_SIZE(bio) (bio)->bi_iter.bi_size
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#define BIO_BI_IDX(bio) (bio)->bi_iter.bi_idx
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#define bio_for_each_segment4(bv, bvp, b, i) \
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bio_for_each_segment((bv), (b), (i))
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typedef struct bvec_iter bvec_iterator_t;
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#else
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#define BIO_BI_SECTOR(bio) (bio)->bi_sector
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#define BIO_BI_SIZE(bio) (bio)->bi_size
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#define BIO_BI_IDX(bio) (bio)->bi_idx
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#define bio_for_each_segment4(bv, bvp, b, i) \
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bio_for_each_segment((bvp), (b), (i))
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typedef int bvec_iterator_t;
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#endif
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/*
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* Portable helper for correctly setting the FAILFAST flags. The
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* correct usage has changed 3 times from 2.6.12 to 2.6.38.
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*/
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static inline void
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bio_set_flags_failfast(struct block_device *bdev, int *flags)
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{
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#ifdef CONFIG_BUG
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/*
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* Disable FAILFAST for loopback devices because of the
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* following incorrect BUG_ON() in loop_make_request().
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* This support is also disabled for md devices because the
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* test suite layers md devices on top of loopback devices.
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* This may be removed when the loopback driver is fixed.
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*
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* BUG_ON(!lo || (rw != READ && rw != WRITE));
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*/
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if ((MAJOR(bdev->bd_dev) == LOOP_MAJOR) ||
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(MAJOR(bdev->bd_dev) == MD_MAJOR))
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return;
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#ifdef BLOCK_EXT_MAJOR
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if (MAJOR(bdev->bd_dev) == BLOCK_EXT_MAJOR)
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return;
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#endif /* BLOCK_EXT_MAJOR */
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#endif /* CONFIG_BUG */
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#if defined(HAVE_BIO_RW_FAILFAST_DTD)
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/* BIO_RW_FAILFAST_* preferred interface from 2.6.28 - 2.6.35 */
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*flags |= (
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(1 << BIO_RW_FAILFAST_DEV) |
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(1 << BIO_RW_FAILFAST_TRANSPORT) |
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(1 << BIO_RW_FAILFAST_DRIVER));
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#elif defined(HAVE_REQ_FAILFAST_MASK)
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/*
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* REQ_FAILFAST_* preferred interface from 2.6.36 - 2.6.xx,
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* the BIO_* and REQ_* flags were unified under REQ_* flags.
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*/
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*flags |= REQ_FAILFAST_MASK;
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#else
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#error "Undefined block IO FAILFAST interface."
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#endif
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}
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/*
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* Maximum disk label length, it may be undefined for some kernels.
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*/
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#ifndef DISK_NAME_LEN
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#define DISK_NAME_LEN 32
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#endif /* DISK_NAME_LEN */
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/*
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* 2.6.24 API change,
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* The bio_end_io() prototype changed slightly. These are helper
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* macro's to ensure the prototype and return value are handled.
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*/
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#ifdef HAVE_2ARGS_BIO_END_IO_T
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#define BIO_END_IO_PROTO(fn, x, y, z) static void fn(struct bio *x, int z)
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#define BIO_END_IO_RETURN(rc) return
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#else
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#define BIO_END_IO_PROTO(fn, x, y, z) static int fn( \
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struct bio *x, \
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unsigned int y, \
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int z)
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#define BIO_END_IO_RETURN(rc) return rc
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#endif /* HAVE_2ARGS_BIO_END_IO_T */
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/*
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* 2.6.38 - 2.6.x API,
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* blkdev_get_by_path()
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* blkdev_put()
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*
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* 2.6.28 - 2.6.37 API,
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* open_bdev_exclusive()
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* close_bdev_exclusive()
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*
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* 2.6.12 - 2.6.27 API,
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* open_bdev_excl()
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* close_bdev_excl()
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*
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* Used to exclusively open a block device from within the kernel.
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*/
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#if defined(HAVE_BLKDEV_GET_BY_PATH)
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#define vdev_bdev_open(path, md, hld) blkdev_get_by_path(path, \
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(md) | FMODE_EXCL, hld)
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#define vdev_bdev_close(bdev, md) blkdev_put(bdev, (md) | FMODE_EXCL)
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#elif defined(HAVE_OPEN_BDEV_EXCLUSIVE)
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#define vdev_bdev_open(path, md, hld) open_bdev_exclusive(path, md, hld)
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#define vdev_bdev_close(bdev, md) close_bdev_exclusive(bdev, md)
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#else
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#define vdev_bdev_open(path, md, hld) open_bdev_excl(path, md, hld)
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#define vdev_bdev_close(bdev, md) close_bdev_excl(bdev)
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#endif /* HAVE_BLKDEV_GET_BY_PATH | HAVE_OPEN_BDEV_EXCLUSIVE */
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/*
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* 2.6.22 API change
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* The function invalidate_bdev() lost it's second argument because
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* it was unused.
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*/
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#ifdef HAVE_1ARG_INVALIDATE_BDEV
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#define vdev_bdev_invalidate(bdev) invalidate_bdev(bdev)
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#else
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#define vdev_bdev_invalidate(bdev) invalidate_bdev(bdev, 1)
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#endif /* HAVE_1ARG_INVALIDATE_BDEV */
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/*
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* 2.6.27 API change
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* The function was exported for use, prior to this it existed by the
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* symbol was not exported.
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*/
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#ifndef HAVE_LOOKUP_BDEV
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#define lookup_bdev(path) ERR_PTR(-ENOTSUP)
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#endif
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/*
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* 2.6.30 API change
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* To ensure good performance preferentially use the physical block size
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* for proper alignment. The physical size is supposed to be the internal
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* sector size used by the device. This is often 4096 byte for AF devices,
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* while a smaller 512 byte logical size is supported for compatibility.
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*
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* Unfortunately, many drives still misreport their physical sector size.
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* For devices which are known to lie you may need to manually set this
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* at pool creation time with 'zpool create -o ashift=12 ...'.
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*
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* When the physical block size interface isn't available, we fall back to
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* the logical block size interface and then the older hard sector size.
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*/
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#ifdef HAVE_BDEV_PHYSICAL_BLOCK_SIZE
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#define vdev_bdev_block_size(bdev) bdev_physical_block_size(bdev)
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#else
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#ifdef HAVE_BDEV_LOGICAL_BLOCK_SIZE
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#define vdev_bdev_block_size(bdev) bdev_logical_block_size(bdev)
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#else
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#define vdev_bdev_block_size(bdev) bdev_hardsect_size(bdev)
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#endif /* HAVE_BDEV_LOGICAL_BLOCK_SIZE */
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#endif /* HAVE_BDEV_PHYSICAL_BLOCK_SIZE */
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/*
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* 2.6.37 API change
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* The WRITE_FLUSH, WRITE_FUA, and WRITE_FLUSH_FUA flags have been
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* introduced as a replacement for WRITE_BARRIER. This was done to
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* allow richer semantics to be expressed to the block layer. It is
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* the block layers responsibility to choose the correct way to
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* implement these semantics.
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*
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* The existence of these flags implies that REQ_FLUSH an REQ_FUA are
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* defined. Thus we can safely define VDEV_REQ_FLUSH and VDEV_REQ_FUA
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* compatibility macros.
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*/
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#ifdef WRITE_FLUSH_FUA
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#define VDEV_WRITE_FLUSH_FUA WRITE_FLUSH_FUA
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#define VDEV_REQ_FLUSH REQ_FLUSH
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#define VDEV_REQ_FUA REQ_FUA
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#else
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#define VDEV_WRITE_FLUSH_FUA WRITE_BARRIER
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#ifdef HAVE_BIO_RW_BARRIER
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#define VDEV_REQ_FLUSH (1 << BIO_RW_BARRIER)
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#define VDEV_REQ_FUA (1 << BIO_RW_BARRIER)
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#else
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#define VDEV_REQ_FLUSH REQ_HARDBARRIER
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#define VDEV_REQ_FUA REQ_FUA
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#endif
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#endif
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/*
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* 2.6.32 API change
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* Use the normal I/O patch for discards.
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*/
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#ifdef QUEUE_FLAG_DISCARD
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#ifdef HAVE_BIO_RW_DISCARD
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#define VDEV_REQ_DISCARD (1 << BIO_RW_DISCARD)
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#else
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#define VDEV_REQ_DISCARD REQ_DISCARD
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#endif
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#else
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#error "Allowing the build will cause discard requests to become writes "
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"potentially triggering the DMU_MAX_ACCESS assertion. Please file a "
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"an issue report at: https://github.com/zfsonlinux/zfs/issues/new"
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#endif
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/*
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* 2.6.33 API change
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* Discard granularity and alignment restrictions may now be set. For
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* older kernels which do not support this it is safe to skip it.
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*/
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#ifdef HAVE_DISCARD_GRANULARITY
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static inline void
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blk_queue_discard_granularity(struct request_queue *q, unsigned int dg)
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{
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q->limits.discard_granularity = dg;
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}
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#else
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#define blk_queue_discard_granularity(x, dg) ((void)0)
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#endif /* HAVE_DISCARD_GRANULARITY */
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/*
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* Default Linux IO Scheduler,
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* Setting the scheduler to noop will allow the Linux IO scheduler to
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* still perform front and back merging, while leaving the request
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* ordering and prioritization to the ZFS IO scheduler.
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*/
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#define VDEV_SCHEDULER "noop"
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/*
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* A common holder for vdev_bdev_open() is used to relax the exclusive open
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* semantics slightly. Internal vdev disk callers may pass VDEV_HOLDER to
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* allow them to open the device multiple times. Other kernel callers and
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* user space processes which don't pass this value will get EBUSY. This is
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* currently required for the correct operation of hot spares.
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*/
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#define VDEV_HOLDER ((void *)0x2401de7)
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#endif /* _ZFS_BLKDEV_H */
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