1 /* 2 * Copyright (c) 1989 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Rick Macklem at The University of Guelph. 7 * 8 * Redistribution and use in source and binary forms are permitted 9 * provided that the above copyright notice and this paragraph are 10 * duplicated in all such forms and that any documentation, 11 * advertising materials, and other materials related to such 12 * distribution and use acknowledge that the software was developed 13 * by the University of California, Berkeley. The name of the 14 * University may not be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 19 * 20 * @(#)nfs_bio.c 7.14 (Berkeley) 05/18/90 21 */ 22 23 #include "param.h" 24 #include "user.h" 25 #include "buf.h" 26 #include "vnode.h" 27 #include "trace.h" 28 #include "mount.h" 29 #include "nfsnode.h" 30 #include "nfsv2.h" 31 #include "nfs.h" 32 #include "nfsiom.h" 33 #include "nfsmount.h" 34 35 /* True and false, how exciting */ 36 #define TRUE 1 37 #define FALSE 0 38 39 /* 40 * Vnode op for read using bio 41 * Any similarity to readip() is purely coincidental 42 */ 43 nfs_bioread(vp, uio, ioflag, cred) 44 register struct vnode *vp; 45 struct uio *uio; 46 int ioflag; 47 struct ucred *cred; 48 { 49 register struct nfsnode *np = VTONFS(vp); 50 struct buf *bp; 51 struct vattr vattr; 52 daddr_t lbn, bn, rablock; 53 int diff, error = 0; 54 long n, on; 55 56 #ifdef lint 57 ioflag = ioflag; 58 #endif /* lint */ 59 if (uio->uio_rw != UIO_READ) 60 panic("nfs_read mode"); 61 if (uio->uio_resid == 0) 62 return (0); 63 if (uio->uio_offset < 0 && vp->v_type != VDIR) 64 return (EINVAL); 65 /* 66 * If the file's modify time on the server has changed since the 67 * last read rpc or you have written to the file, 68 * you may have lost data cache consistency with the 69 * server, so flush all of the file's data out of the cache. 70 * Then force a getattr rpc to ensure that you have up to date 71 * attributes. 72 * NB: This implies that cache data can be read when up to 73 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 74 * attributes this could be forced by setting n_attrstamp to 0 before 75 * the nfs_getattr() call. 76 */ 77 if (vp->v_type != VLNK) { 78 if (np->n_flag & NMODIFIED) { 79 np->n_flag &= ~NMODIFIED; 80 vinvalbuf(vp, TRUE); 81 np->n_attrstamp = 0; 82 np->n_direofoffset = 0; 83 if (error = nfs_getattr(vp, &vattr, cred)) 84 return (error); 85 np->n_mtime = vattr.va_mtime.tv_sec; 86 } else { 87 if (error = nfs_getattr(vp, &vattr, cred)) 88 return (error); 89 if (np->n_mtime != vattr.va_mtime.tv_sec) { 90 np->n_direofoffset = 0; 91 vinvalbuf(vp, TRUE); 92 np->n_mtime = vattr.va_mtime.tv_sec; 93 } 94 } 95 } 96 do { 97 switch (vp->v_type) { 98 case VREG: 99 nfsstats.biocache_reads++; 100 lbn = uio->uio_offset >> NFS_BIOSHIFT; 101 on = uio->uio_offset & (NFS_BIOSIZE-1); 102 n = MIN((unsigned)(NFS_BIOSIZE - on), uio->uio_resid); 103 diff = np->n_size - uio->uio_offset; 104 if (diff <= 0) 105 return (error); 106 if (diff < n) 107 n = diff; 108 bn = lbn*(NFS_BIOSIZE/DEV_BSIZE); 109 rablock = (lbn+1)*(NFS_BIOSIZE/DEV_BSIZE); 110 if (vp->v_lastr + 1 == lbn && 111 np->n_size > (rablock * DEV_BSIZE)) 112 error = breada(vp, bn, NFS_BIOSIZE, rablock, NFS_BIOSIZE, 113 cred, &bp); 114 else 115 error = bread(vp, bn, NFS_BIOSIZE, cred, &bp); 116 vp->v_lastr = lbn; 117 if (bp->b_resid) { 118 diff = (on >= (NFS_BIOSIZE-bp->b_resid)) ? 0 : 119 (NFS_BIOSIZE-bp->b_resid-on); 120 n = MIN(n, diff); 121 } 122 break; 123 case VLNK: 124 nfsstats.biocache_readlinks++; 125 on = 0; 126 error = bread(vp, (daddr_t)0, NFS_MAXPATHLEN, cred, &bp); 127 n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 128 break; 129 case VDIR: 130 nfsstats.biocache_readdirs++; 131 on = 0; 132 error = bread(vp, uio->uio_offset, DIRBLKSIZ, cred, &bp); 133 n = MIN(uio->uio_resid, DIRBLKSIZ - bp->b_resid); 134 break; 135 }; 136 if (error) { 137 brelse(bp); 138 return (error); 139 } 140 if (n > 0) 141 error = uiomove(bp->b_un.b_addr + on, (int)n, uio); 142 switch (vp->v_type) { 143 case VREG: 144 if (n+on == NFS_BIOSIZE || uio->uio_offset == np->n_size) 145 bp->b_flags |= B_AGE; 146 break; 147 case VLNK: 148 n = 0; 149 break; 150 case VDIR: 151 uio->uio_offset = bp->b_blkno; 152 break; 153 }; 154 brelse(bp); 155 } while (error == 0 && uio->uio_resid > 0 && n != 0); 156 return (error); 157 } 158 159 /* 160 * Vnode op for write using bio 161 */ 162 nfs_write(vp, uio, ioflag, cred) 163 register struct vnode *vp; 164 register struct uio *uio; 165 int ioflag; 166 struct ucred *cred; 167 { 168 struct buf *bp; 169 struct nfsnode *np = VTONFS(vp); 170 struct vattr vattr; 171 daddr_t lbn, bn; 172 int n, on, error = 0; 173 174 if (uio->uio_rw != UIO_WRITE) 175 panic("nfs_write mode"); 176 if (vp->v_type != VREG) 177 return (EIO); 178 /* Should we try and do this ?? */ 179 if (ioflag & IO_APPEND) { 180 if (np->n_flag & NMODIFIED) { 181 np->n_flag &= ~NMODIFIED; 182 vinvalbuf(vp, TRUE); 183 } 184 np->n_attrstamp = 0; 185 if (error = nfs_getattr(vp, &vattr, cred)) 186 return (error); 187 uio->uio_offset = np->n_size; 188 return (nfs_writerpc(vp, uio, cred, u.u_procp)); 189 } 190 #ifdef notdef 191 cnt = uio->uio_resid; 192 osize = np->n_size; 193 #endif 194 if (uio->uio_offset < 0) 195 return (EINVAL); 196 if (uio->uio_resid == 0) 197 return (0); 198 /* 199 * Maybe this should be above the vnode op call, but so long as 200 * file servers have no limits, i don't think it matters 201 */ 202 if (uio->uio_offset + uio->uio_resid > 203 u.u_rlimit[RLIMIT_FSIZE].rlim_cur) { 204 psignal(u.u_procp, SIGXFSZ); 205 return (EFBIG); 206 } 207 np->n_flag |= NMODIFIED; 208 do { 209 nfsstats.biocache_writes++; 210 lbn = uio->uio_offset >> NFS_BIOSHIFT; 211 on = uio->uio_offset & (NFS_BIOSIZE-1); 212 n = MIN((unsigned)(NFS_BIOSIZE - on), uio->uio_resid); 213 if (uio->uio_offset+n > np->n_size) 214 np->n_size = uio->uio_offset+n; 215 bn = lbn*(NFS_BIOSIZE/DEV_BSIZE); 216 again: 217 bp = getblk(vp, bn, NFS_BIOSIZE); 218 if (bp->b_wcred == NOCRED) { 219 crhold(cred); 220 bp->b_wcred = cred; 221 } 222 if (bp->b_dirtyend > 0) { 223 /* 224 * If the new write will leave a contiguous dirty 225 * area, just update the b_dirtyoff and b_dirtyend, 226 * otherwise force a write rpc of the old dirty area. 227 */ 228 if (on <= bp->b_dirtyend && (on+n) >= bp->b_dirtyoff) { 229 bp->b_dirtyoff = MIN(on, bp->b_dirtyoff); 230 bp->b_dirtyend = MAX((on+n), bp->b_dirtyend); 231 } else { 232 bp->b_proc = u.u_procp; 233 if (error = bwrite(bp)) 234 return (error); 235 goto again; 236 } 237 } else { 238 bp->b_dirtyoff = on; 239 bp->b_dirtyend = on+n; 240 } 241 if (error = uiomove(bp->b_un.b_addr + on, n, uio)) { 242 brelse(bp); 243 return (error); 244 } 245 if ((n+on) == NFS_BIOSIZE) { 246 bp->b_flags |= B_AGE; 247 bp->b_proc = (struct proc *)0; 248 bawrite(bp); 249 } else { 250 bp->b_proc = (struct proc *)0; 251 bdwrite(bp); 252 } 253 } while (error == 0 && uio->uio_resid > 0 && n != 0); 254 #ifdef notdef 255 /* Should we try and do this for nfs ?? */ 256 if (error && (ioflag & IO_UNIT)) { 257 np->n_size = osize; 258 uio->uio_offset -= cnt - uio->uio_resid; 259 uio->uio_resid = cnt; 260 } 261 #endif 262 return (error); 263 } 264