include/os/linux/spl/sys/uio.h

   1 /*
   2  *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
   3  *  Copyright (C) 2007 The Regents of the University of California.
   4  *  Copyright (c) 2015 by Chunwei Chen. All rights reserved.
   5  *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
   6  *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
   7  *  UCRL-CODE-235197
   8  *
   9  *  This file is part of the SPL, Solaris Porting Layer.
  10  *
  11  *  The SPL is free software; you can redistribute it and/or modify it
  12  *  under the terms of the GNU General Public License as published by the
  13  *  Free Software Foundation; either version 2 of the License, or (at your
  14  *  option) any later version.
  15  *
  16  *  The SPL is distributed in the hope that it will be useful, but WITHOUT
  17  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  18  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  19  *  for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License along
  22  *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
  23  */
  24
  25 #ifndef _SPL_UIO_H
  26 #define _SPL_UIO_H
  27
  28 #include <sys/debug.h>
  29 #include <linux/uio.h>
  30 #include <linux/blkdev.h>
  31 #include <linux/blkdev_compat.h>
  32 #include <linux/mm.h>
  33 #include <linux/bio.h>
  34 #include <asm/uaccess.h>
  35 #include <sys/types.h>
  36
  37 #if defined(HAVE_VFS_IOV_ITER) && defined(HAVE_FAULT_IN_IOV_ITER_READABLE)
  38 #define iov_iter_fault_in_readable(a, b)        fault_in_iov_iter_readable(a, b)
  39 #endif
  40
  41 typedef struct iovec iovec_t;
  42
  43 typedef enum zfs_uio_rw {
  44         UIO_READ =              0,
  45         UIO_WRITE =             1,
  46 } zfs_uio_rw_t;
  47
  48 typedef enum zfs_uio_seg {
  49         UIO_USERSPACE =         0,
  50         UIO_SYSSPACE =          1,
  51         UIO_BVEC =              2,
  52 #if defined(HAVE_VFS_IOV_ITER)
  53         UIO_ITER =              3,
  54 #endif
  55 } zfs_uio_seg_t;
  56
  57 typedef struct zfs_uio {
  58         union {
  59                 const struct iovec      *uio_iov;
  60                 const struct bio_vec    *uio_bvec;
  61 #if defined(HAVE_VFS_IOV_ITER)
  62                 struct iov_iter         *uio_iter;
  63 #endif
  64         };
  65         int             uio_iovcnt;
  66         offset_t        uio_loffset;
  67         zfs_uio_seg_t   uio_segflg;
  68         boolean_t       uio_fault_disable;
  69         uint16_t        uio_fmode;
  70         uint16_t        uio_extflg;
  71         ssize_t         uio_resid;
  72
  73         size_t          uio_skip;
  74
  75         struct request  *rq;
  76
  77         /*
  78          * Used for saving rq_for_each_segment() state between calls
  79          * to zfs_uiomove_bvec_rq().
  80          */
  81         struct req_iterator iter;
  82         struct bio_vec bv;
  83 } zfs_uio_t;
  84
  85
  86 #define zfs_uio_segflg(u)               (u)->uio_segflg
  87 #define zfs_uio_offset(u)               (u)->uio_loffset
  88 #define zfs_uio_resid(u)                (u)->uio_resid
  89 #define zfs_uio_iovcnt(u)               (u)->uio_iovcnt
  90 #define zfs_uio_iovlen(u, idx)          (u)->uio_iov[(idx)].iov_len
  91 #define zfs_uio_iovbase(u, idx)         (u)->uio_iov[(idx)].iov_base
  92 #define zfs_uio_fault_disable(u, set)   (u)->uio_fault_disable = set
  93 #define zfs_uio_rlimit_fsize(z, u)      (0)
  94 #define zfs_uio_fault_move(p, n, rw, u) zfs_uiomove((p), (n), (rw), (u))
  95
  96 extern int zfs_uio_prefaultpages(ssize_t, zfs_uio_t *);
  97
  98 static inline void
  99 zfs_uio_setoffset(zfs_uio_t *uio, offset_t off)
 100 {
 101         uio->uio_loffset = off;
 102 }
 103
 104 static inline void
 105 zfs_uio_advance(zfs_uio_t *uio, size_t size)
 106 {
 107         uio->uio_resid -= size;
 108         uio->uio_loffset += size;
 109 }
 110
 111 static inline void
 112 zfs_uio_iovec_init(zfs_uio_t *uio, const struct iovec *iov,
 113     unsigned long nr_segs, offset_t offset, zfs_uio_seg_t seg, ssize_t resid,
 114     size_t skip)
 115 {
 116         ASSERT(seg == UIO_USERSPACE || seg == UIO_SYSSPACE);
 117
 118         uio->uio_iov = iov;
 119         uio->uio_iovcnt = nr_segs;
 120         uio->uio_loffset = offset;
 121         uio->uio_segflg = seg;
 122         uio->uio_fault_disable = B_FALSE;
 123         uio->uio_fmode = 0;
 124         uio->uio_extflg = 0;
 125         uio->uio_resid = resid;
 126         uio->uio_skip = skip;
 127 }
 128
 129 static inline void
 130 zfs_uio_bvec_init(zfs_uio_t *uio, struct bio *bio, struct request *rq)
 131 {
 132         /* Either bio or rq will be set, but not both */
 133         ASSERT3P(uio, !=, bio);
 134
 135         if (bio) {
 136                 uio->uio_iovcnt = bio->bi_vcnt - BIO_BI_IDX(bio);
 137                 uio->uio_bvec = &bio->bi_io_vec[BIO_BI_IDX(bio)];
 138         } else {
 139                 uio->uio_bvec = NULL;
 140                 uio->uio_iovcnt = 0;
 141                 memset(&uio->iter, 0, sizeof (uio->iter));
 142         }
 143
 144         uio->uio_loffset = io_offset(bio, rq);
 145         uio->uio_segflg = UIO_BVEC;
 146         uio->uio_fault_disable = B_FALSE;
 147         uio->uio_fmode = 0;
 148         uio->uio_extflg = 0;
 149         uio->uio_resid = io_size(bio, rq);
 150         if (bio) {
 151                 uio->uio_skip = BIO_BI_SKIP(bio);
 152         } else {
 153                 uio->uio_skip = 0;
 154         }
 155
 156         uio->rq = rq;
 157 }
 158
 159 #if defined(HAVE_VFS_IOV_ITER)
 160 static inline void
 161 zfs_uio_iov_iter_init(zfs_uio_t *uio, struct iov_iter *iter, offset_t offset,
 162     ssize_t resid, size_t skip)
 163 {
 164         uio->uio_iter = iter;
 165         uio->uio_iovcnt = iter->nr_segs;
 166         uio->uio_loffset = offset;
 167         uio->uio_segflg = UIO_ITER;
 168         uio->uio_fault_disable = B_FALSE;
 169         uio->uio_fmode = 0;
 170         uio->uio_extflg = 0;
 171         uio->uio_resid = resid;
 172         uio->uio_skip = skip;
 173 }
 174 #endif
 175
 176 #if defined(HAVE_ITER_IOV)
 177 #define zfs_uio_iter_iov(iter)  iter_iov((iter))
 178 #else
 179 #define zfs_uio_iter_iov(iter)  (iter)->iov
 180 #endif
 181
 182 #if defined(HAVE_IOV_ITER_TYPE)
 183 #define zfs_uio_iov_iter_type(iter)     iov_iter_type((iter))
 184 #else
 185 #define zfs_uio_iov_iter_type(iter)     (iter)->type
 186 #endif
 187
 188 #endif /* SPL_UIO_H */