kernel: Move GPL'd kernel files to sys/gnu to have them all in one place.
[dragonfly.git] / sys / gnu / vfs / ext2fs / ext2_readwrite.c
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1/*
2 * modified for Lites 1.1
3 *
4 * Aug 1995, Godmar Back (gback@cs.utah.edu)
5 * University of Utah, Department of Computer Science
6 */
7/*
8 * Copyright (c) 1993
9 * The Regents of the University of California. All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the University of
22 * California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 * @(#)ufs_readwrite.c 8.7 (Berkeley) 1/21/94
40 * $FreeBSD: src/sys/gnu/ext2fs/ext2_readwrite.c,v 1.18.2.2 2000/12/22 18:44:33 dillon Exp $
41 */
42
43#define BLKSIZE(a, b, c) blksize(a, b, c)
44#define FS struct ext2_sb_info
45#define I_FS i_e2fs
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46
47/*
48 * Vnode op for reading.
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49 *
50 * ext2_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
51 * struct ucred *a_cred)
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52 */
53/* ARGSUSED */
54static int
0f7f7a49 55ext2_read(struct vop_read_args *ap)
984263bc 56{
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57 struct vnode *vp;
58 struct inode *ip;
59 struct uio *uio;
60 FS *fs;
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61 struct buf *bp;
62 daddr_t lbn, nextlbn;
54078292 63 off_t nextloffset;
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64 off_t bytesinfile;
65 long size, xfersize, blkoffset;
66 int error, orig_resid;
67 int seqcount = ap->a_ioflag >> 16;
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68
69 vp = ap->a_vp;
70 ip = VTOI(vp);
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71 uio = ap->a_uio;
72
73#ifdef DIAGNOSTIC
74 if (uio->uio_rw != UIO_READ)
5197887a 75 panic("ext2_read: mode");
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76
77 if (vp->v_type == VLNK) {
78 if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen)
5197887a 79 panic("ext2_read: short symlink");
984263bc 80 } else if (vp->v_type != VREG && vp->v_type != VDIR)
5197887a 81 panic("ext2_read: type %d", vp->v_type);
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82#endif
83 fs = ip->I_FS;
84#if 0
85 if ((u_quad_t)uio->uio_offset > fs->fs_maxfilesize)
86 return (EFBIG);
87#endif
88
89 orig_resid = uio->uio_resid;
90 for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) {
91 if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0)
92 break;
93 lbn = lblkno(fs, uio->uio_offset);
94 nextlbn = lbn + 1;
54078292 95 nextloffset = lblktodoff(fs, nextlbn);
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96 size = BLKSIZE(fs, ip, lbn);
97 blkoffset = blkoff(fs, uio->uio_offset);
98
99 xfersize = fs->s_frag_size - blkoffset;
100 if (uio->uio_resid < xfersize)
101 xfersize = uio->uio_resid;
102 if (bytesinfile < xfersize)
103 xfersize = bytesinfile;
104
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105 if (nextloffset >= ip->i_size) {
106 error = bread(vp, lblktodoff(fs, lbn), size, &bp);
107 } else if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERR) == 0) {
108 error = cluster_read(vp, (off_t)ip->i_size,
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109 lblktodoff(fs, lbn), size,
110 uio->uio_resid,
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111 (ap->a_ioflag >> 16) * BKVASIZE,
112 &bp);
54078292 113 } else if (seqcount > 1) {
984263bc 114 int nextsize = BLKSIZE(fs, ip, nextlbn);
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115 error = breadn(vp, lblktodoff(fs, lbn),
116 size, &nextloffset, &nextsize, 1, &bp);
117 } else {
118 error = bread(vp, lblktodoff(fs, lbn), size, &bp);
119 }
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120 if (error) {
121 brelse(bp);
122 bp = NULL;
123 break;
124 }
125
126 /*
127 * We should only get non-zero b_resid when an I/O error
128 * has occurred, which should cause us to break above.
129 * However, if the short read did not cause an error,
130 * then we want to ensure that we do not uiomove bad
131 * or uninitialized data.
132 */
133 size -= bp->b_resid;
134 if (size < xfersize) {
135 if (size == 0)
136 break;
137 xfersize = size;
138 }
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139 error = uiomove((char *)bp->b_data + blkoffset,
140 (int)xfersize, uio);
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141 if (error)
142 break;
143
144 bqrelse(bp);
145 }
146 if (bp != NULL)
147 bqrelse(bp);
148 if (orig_resid > 0 && (error == 0 || uio->uio_resid != orig_resid) &&
149 (vp->v_mount->mnt_flag & MNT_NOATIME) == 0)
150 ip->i_flag |= IN_ACCESS;
151 return (error);
152}
153
154/*
155 * Vnode op for writing.
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156 *
157 * ext2_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
158 * struct ucred *a_cred)
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159 */
160static int
0f7f7a49 161ext2_write(struct vop_write_args *ap)
984263bc 162{
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163 struct vnode *vp;
164 struct uio *uio;
165 struct inode *ip;
166 FS *fs;
984263bc 167 struct buf *bp;
7b95be2a 168 struct thread *td;
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169 daddr_t lbn;
170 off_t osize;
171 int seqcount;
172 int blkoffset, error, flags, ioflag, resid, size, xfersize;
173
174 ioflag = ap->a_ioflag;
175 seqcount = ap->a_ioflag >> 16;
176 uio = ap->a_uio;
177 vp = ap->a_vp;
178 ip = VTOI(vp);
179
180#ifdef DIAGNOSTIC
181 if (uio->uio_rw != UIO_WRITE)
5197887a 182 panic("ext2_write: mode");
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183#endif
184
185 switch (vp->v_type) {
186 case VREG:
187 if (ioflag & IO_APPEND)
188 uio->uio_offset = ip->i_size;
189 if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
190 return (EPERM);
191 /* FALLTHROUGH */
192 case VLNK:
193 break;
194 case VDIR:
195 if ((ioflag & IO_SYNC) == 0)
5197887a 196 panic("ext2_write: nonsync dir write");
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197 break;
198 default:
5197887a 199 panic("ext2_write: type");
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200 }
201
202 fs = ip->I_FS;
203#if 0
204 if (uio->uio_offset < 0 ||
205 (u_quad_t)uio->uio_offset + uio->uio_resid > fs->fs_maxfilesize)
206 return (EFBIG);
207#endif
208 /*
209 * Maybe this should be above the vnode op call, but so long as
210 * file servers have no limits, I don't think it matters.
211 */
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212 td = uio->uio_td;
213 if (vp->v_type == VREG && td && td->td_proc &&
984263bc 214 uio->uio_offset + uio->uio_resid >
7b95be2a 215 td->td_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
7278a846 216 lwpsignal(td->td_proc, td->td_lwp, SIGXFSZ);
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217 return (EFBIG);
218 }
219
220 resid = uio->uio_resid;
221 osize = ip->i_size;
222 flags = ioflag & IO_SYNC ? B_SYNC : 0;
223
224 for (error = 0; uio->uio_resid > 0;) {
225 lbn = lblkno(fs, uio->uio_offset);
226 blkoffset = blkoff(fs, uio->uio_offset);
227 xfersize = fs->s_frag_size - blkoffset;
228 if (uio->uio_resid < xfersize)
229 xfersize = uio->uio_resid;
230
231 if (uio->uio_offset + xfersize > ip->i_size)
232 vnode_pager_setsize(vp, uio->uio_offset + xfersize);
233
b993bb87 234 /*
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235 * Avoid a data-consistency race between write() and mmap()
236 * by ensuring that newly allocated blocks are zerod. The
237 * race can occur even in the case where the write covers
238 * the entire block.
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239 *
240 * Just set B_CLRBUF unconditionally, even if the write
241 * covers the whole block. This also handles the UIO_NOCOPY
242 * case. See ffs_write() in ufs for a more sophisticated
243 * version.
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244 */
245 flags |= B_CLRBUF;
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246 error = ext2_balloc(ip, lbn, blkoffset + xfersize,
247 ap->a_cred, &bp, flags);
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248 if (error)
249 break;
250
251 if (uio->uio_offset + xfersize > ip->i_size) {
252 ip->i_size = uio->uio_offset + xfersize;
253 }
254
255 size = BLKSIZE(fs, ip, lbn) - bp->b_resid;
256 if (size < xfersize)
257 xfersize = size;
258
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259 error = uiomove((char *)bp->b_data + blkoffset,
260 (int)xfersize, uio);
984263bc 261 if ((ioflag & IO_VMIO) &&
c081fe84 262 LIST_FIRST(&bp->b_dep) == NULL) /* in ext2fs? */
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263 bp->b_flags |= B_RELBUF;
264
265 if (ioflag & IO_SYNC) {
b1ce5639 266 bwrite(bp);
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267 } else if (xfersize + blkoffset == fs->s_frag_size) {
268 if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
269 bp->b_flags |= B_CLUSTEROK;
e92ca23a 270 cluster_write(bp, (off_t)ip->i_size, vp->v_mount->mnt_stat.f_iosize, seqcount);
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271 } else {
272 bawrite(bp);
273 }
274 } else {
275 bp->b_flags |= B_CLUSTEROK;
276 bdwrite(bp);
277 }
278 if (error || xfersize == 0)
279 break;
280 ip->i_flag |= IN_CHANGE | IN_UPDATE;
281 }
282 /*
283 * If we successfully wrote any data, and we are not the superuser
284 * we clear the setuid and setgid bits as a precaution against
285 * tampering.
286 */
287 if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0)
288 ip->i_mode &= ~(ISUID | ISGID);
289 if (error) {
290 if (ioflag & IO_UNIT) {
87de5057 291 EXT2_TRUNCATE(vp, osize, ioflag & IO_SYNC, ap->a_cred);
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292 uio->uio_offset -= resid - uio->uio_resid;
293 uio->uio_resid = resid;
294 }
295 } else if (resid > uio->uio_resid && (ioflag & IO_SYNC))
1f1db49f 296 error = EXT2_UPDATE(vp, 1);
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297 return (error);
298}