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 } zfs_uio_t;
  77
  78
  79 #define zfs_uio_segflg(u)               (u)->uio_segflg
  80 #define zfs_uio_offset(u)               (u)->uio_loffset
  81 #define zfs_uio_resid(u)                (u)->uio_resid
  82 #define zfs_uio_iovcnt(u)               (u)->uio_iovcnt
  83 #define zfs_uio_iovlen(u, idx)          (u)->uio_iov[(idx)].iov_len
  84 #define zfs_uio_iovbase(u, idx)         (u)->uio_iov[(idx)].iov_base
  85 #define zfs_uio_fault_disable(u, set)   (u)->uio_fault_disable = set
  86 #define zfs_uio_rlimit_fsize(z, u)      (0)
  87 #define zfs_uio_fault_move(p, n, rw, u) zfs_uiomove((p), (n), (rw), (u))
  88
  89 extern int zfs_uio_prefaultpages(ssize_t, zfs_uio_t *);
  90
  91 static inline void
  92 zfs_uio_setoffset(zfs_uio_t *uio, offset_t off)
  93 {
  94         uio->uio_loffset = off;
  95 }
  96
  97 static inline void
  98 zfs_uio_advance(zfs_uio_t *uio, size_t size)
  99 {
 100         uio->uio_resid -= size;
 101         uio->uio_loffset += size;
 102 }
 103
 104 static inline void
 105 zfs_uio_iovec_init(zfs_uio_t *uio, const struct iovec *iov,
 106     unsigned long nr_segs, offset_t offset, zfs_uio_seg_t seg, ssize_t resid,
 107     size_t skip)
 108 {
 109         ASSERT(seg == UIO_USERSPACE || seg == UIO_SYSSPACE);
 110
 111         uio->uio_iov = iov;
 112         uio->uio_iovcnt = nr_segs;
 113         uio->uio_loffset = offset;
 114         uio->uio_segflg = seg;
 115         uio->uio_fault_disable = B_FALSE;
 116         uio->uio_fmode = 0;
 117         uio->uio_extflg = 0;
 118         uio->uio_resid = resid;
 119         uio->uio_skip = skip;
 120 }
 121
 122 static inline void
 123 zfs_uio_bvec_init(zfs_uio_t *uio, struct bio *bio, struct request *rq)
 124 {
 125         /* Either bio or rq will be set, but not both */
 126         ASSERT3P(uio, !=, bio);
 127
 128         if (bio) {
 129                 uio->uio_iovcnt = bio->bi_vcnt - BIO_BI_IDX(bio);
 130                 uio->uio_bvec = &bio->bi_io_vec[BIO_BI_IDX(bio)];
 131         } else {
 132                 uio->uio_bvec = NULL;
 133                 uio->uio_iovcnt = 0;
 134         }
 135
 136         uio->uio_loffset = io_offset(bio, rq);
 137         uio->uio_segflg = UIO_BVEC;
 138         uio->uio_fault_disable = B_FALSE;
 139         uio->uio_fmode = 0;
 140         uio->uio_extflg = 0;
 141         uio->uio_resid = io_size(bio, rq);
 142         if (bio) {
 143                 uio->uio_skip = BIO_BI_SKIP(bio);
 144         } else {
 145                 uio->uio_skip = 0;
 146         }
 147
 148         uio->rq = rq;
 149 }
 150
 151 #if defined(HAVE_VFS_IOV_ITER)
 152 static inline void
 153 zfs_uio_iov_iter_init(zfs_uio_t *uio, struct iov_iter *iter, offset_t offset,
 154     ssize_t resid, size_t skip)
 155 {
 156         uio->uio_iter = iter;
 157         uio->uio_iovcnt = iter->nr_segs;
 158         uio->uio_loffset = offset;
 159         uio->uio_segflg = UIO_ITER;
 160         uio->uio_fault_disable = B_FALSE;
 161         uio->uio_fmode = 0;
 162         uio->uio_extflg = 0;
 163         uio->uio_resid = resid;
 164         uio->uio_skip = skip;
 165 }
 166 #endif
 167
 168 #if defined(HAVE_ITER_IOV)
 169 #define zfs_uio_iter_iov(iter)  iter_iov((iter))
 170 #else
 171 #define zfs_uio_iter_iov(iter)  (iter)->iov
 172 #endif
 173
 174 #if defined(HAVE_IOV_ITER_TYPE)
 175 #define zfs_uio_iov_iter_type(iter)     iov_iter_type((iter))
 176 #else
 177 #define zfs_uio_iov_iter_type(iter)     (iter)->type
 178 #endif
 179
 180 #endif /* SPL_UIO_H */