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 #include <sys/string.h>
37
38 /*
39 * uio_extflg: extended flags
40 */
41 #define UIO_DIRECT 0x0001 /* Direct I/O request */
42
43 #if defined(HAVE_FAULT_IN_IOV_ITER_READABLE)
44 #define iov_iter_fault_in_readable(a, b) fault_in_iov_iter_readable(a, b)
45 #endif
46
47 typedef struct iovec iovec_t;
48
49 typedef enum zfs_uio_rw {
50 UIO_READ = 0,
51 UIO_WRITE = 1,
52 } zfs_uio_rw_t;
53
54 typedef enum zfs_uio_seg {
55 UIO_SYSSPACE = 0,
56 UIO_BVEC = 1,
57 UIO_ITER = 2,
58 } zfs_uio_seg_t;
59
60 /*
61 * This structures is used when doing Direct I/O.
62 */
63 typedef struct {
64 struct page **pages; /* Mapped pages */
65 long npages; /* Number of mapped pages */
66 boolean_t pinned; /* Whether FOLL_PIN was used */
67 } zfs_uio_dio_t;
68
69 typedef struct zfs_uio {
70 union {
71 const struct iovec *uio_iov;
72 const struct bio_vec *uio_bvec;
73 struct iov_iter *uio_iter;
74 };
75 int uio_iovcnt; /* Number of iovecs */
76 offset_t uio_soffset; /* Starting logical offset */
77 offset_t uio_loffset; /* Current logical offset */
78 zfs_uio_seg_t uio_segflg; /* Segment type */
79 boolean_t uio_fault_disable;
80 uint16_t uio_fmode; /* Access mode (unused) */
81 uint16_t uio_extflg; /* Extra flags (UIO_DIRECT) */
82 ssize_t uio_resid; /* Residual unprocessed bytes */
83 size_t uio_skip; /* Skipped bytes in current iovec */
84 zfs_uio_dio_t uio_dio; /* Direct I/O user pages */
85
86 struct request *rq;
87 } zfs_uio_t;
88
89
90 #define zfs_uio_segflg(u) (u)->uio_segflg
91 #define zfs_uio_offset(u) (u)->uio_loffset
92 #define zfs_uio_resid(u) (u)->uio_resid
93 #define zfs_uio_iovcnt(u) (u)->uio_iovcnt
94 #define zfs_uio_iovlen(u, idx) (u)->uio_iov[(idx)].iov_len
95 #define zfs_uio_iovbase(u, idx) (u)->uio_iov[(idx)].iov_base
96 #define zfs_uio_fault_disable(u, set) (u)->uio_fault_disable = set
97 #define zfs_uio_soffset(u) (u)->uio_soffset
98 #define zfs_uio_rlimit_fsize(z, u) (0)
99 #define zfs_uio_fault_move(p, n, rw, u) zfs_uiomove((p), (n), (rw), (u))
100
101 extern int zfs_uio_prefaultpages(ssize_t, zfs_uio_t *);
102
103 static inline void
zfs_uio_setoffset(zfs_uio_t * uio,offset_t off)104 zfs_uio_setoffset(zfs_uio_t *uio, offset_t off)
105 {
106 uio->uio_loffset = off;
107 }
108
109 static inline void
zfs_uio_setsoffset(zfs_uio_t * uio,offset_t off)110 zfs_uio_setsoffset(zfs_uio_t *uio, offset_t off)
111 {
112 ASSERT3U(zfs_uio_offset(uio), ==, off);
113 zfs_uio_soffset(uio) = off;
114 }
115
116 static inline void
zfs_uio_advance(zfs_uio_t * uio,ssize_t size)117 zfs_uio_advance(zfs_uio_t *uio, ssize_t size)
118 {
119 uio->uio_resid -= size;
120 uio->uio_loffset += size;
121 }
122
123 static inline void
zfs_uio_iovec_init(zfs_uio_t * uio,const struct iovec * iov,unsigned long nr_segs,offset_t offset,zfs_uio_seg_t seg,ssize_t resid,size_t skip)124 zfs_uio_iovec_init(zfs_uio_t *uio, const struct iovec *iov,
125 unsigned long nr_segs, offset_t offset, zfs_uio_seg_t seg, ssize_t resid,
126 size_t skip)
127 {
128 ASSERT(seg == UIO_SYSSPACE);
129
130 uio->uio_iov = iov;
131 uio->uio_iovcnt = nr_segs;
132 uio->uio_loffset = offset;
133 uio->uio_segflg = seg;
134 uio->uio_fault_disable = B_FALSE;
135 uio->uio_fmode = 0;
136 uio->uio_extflg = 0;
137 uio->uio_resid = resid;
138 uio->uio_skip = skip;
139 uio->uio_soffset = uio->uio_loffset;
140 memset(&uio->uio_dio, 0, sizeof (zfs_uio_dio_t));
141 }
142
143 static inline void
zfs_uio_bvec_init(zfs_uio_t * uio,struct bio * bio,struct request * rq)144 zfs_uio_bvec_init(zfs_uio_t *uio, struct bio *bio, struct request *rq)
145 {
146 /* Either bio or rq will be set, but not both */
147 ASSERT3P(uio, !=, bio);
148
149 if (bio) {
150 uio->uio_iovcnt = bio->bi_vcnt - BIO_BI_IDX(bio);
151 uio->uio_bvec = &bio->bi_io_vec[BIO_BI_IDX(bio)];
152 } else {
153 uio->uio_bvec = NULL;
154 uio->uio_iovcnt = 0;
155 }
156
157 uio->uio_loffset = io_offset(bio, rq);
158 uio->uio_segflg = UIO_BVEC;
159 uio->uio_fault_disable = B_FALSE;
160 uio->uio_fmode = 0;
161 uio->uio_extflg = 0;
162 uio->uio_resid = io_size(bio, rq);
163 if (bio) {
164 uio->uio_skip = BIO_BI_SKIP(bio);
165 } else {
166 uio->uio_skip = 0;
167 }
168
169 uio->rq = rq;
170 uio->uio_soffset = uio->uio_loffset;
171 memset(&uio->uio_dio, 0, sizeof (zfs_uio_dio_t));
172 }
173
174 static inline void
zfs_uio_iov_iter_init(zfs_uio_t * uio,struct iov_iter * iter,offset_t offset,ssize_t resid,size_t skip)175 zfs_uio_iov_iter_init(zfs_uio_t *uio, struct iov_iter *iter, offset_t offset,
176 ssize_t resid, size_t skip)
177 {
178 uio->uio_iter = iter;
179 uio->uio_iovcnt = iter->nr_segs;
180 uio->uio_loffset = offset;
181 uio->uio_segflg = UIO_ITER;
182 uio->uio_fault_disable = B_FALSE;
183 uio->uio_fmode = 0;
184 uio->uio_extflg = 0;
185 uio->uio_resid = resid;
186 uio->uio_skip = skip;
187 uio->uio_soffset = uio->uio_loffset;
188 memset(&uio->uio_dio, 0, sizeof (zfs_uio_dio_t));
189 }
190
191 #if defined(HAVE_ITER_IOV)
192 #define zfs_uio_iter_iov(iter) iter_iov((iter))
193 #else
194 #define zfs_uio_iter_iov(iter) (iter)->iov
195 #endif
196
197 #if defined(HAVE_IOV_ITER_TYPE)
198 #define zfs_uio_iov_iter_type(iter) iov_iter_type((iter))
199 #else
200 #define zfs_uio_iov_iter_type(iter) (iter)->type
201 #endif
202
203 #if defined(HAVE_ITER_IS_UBUF)
204 #define zfs_user_backed_iov_iter(iter) \
205 (iter_is_ubuf((iter)) || \
206 (zfs_uio_iov_iter_type((iter)) == ITER_IOVEC))
207 #else
208 #define zfs_user_backed_iov_iter(iter) \
209 (zfs_uio_iov_iter_type((iter)) == ITER_IOVEC)
210 #endif
211
212 #endif /* SPL_UIO_H */
213