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 * %sccs.include.redist.c% 9 * 10 * @(#)nfs_bio.c 7.18 (Berkeley) 03/19/91 11 */ 12 13 #include "param.h" 14 #include "proc.h" 15 #include "buf.h" 16 #include "vnode.h" 17 #include "trace.h" 18 #include "mount.h" 19 #include "resourcevar.h" 20 21 #include "nfsnode.h" 22 #include "nfsv2.h" 23 #include "nfs.h" 24 #include "nfsiom.h" 25 #include "nfsmount.h" 26 27 /* True and false, how exciting */ 28 #define TRUE 1 29 #define FALSE 0 30 31 /* 32 * Vnode op for read using bio 33 * Any similarity to readip() is purely coincidental 34 */ 35 nfs_bioread(vp, uio, ioflag, cred) 36 register struct vnode *vp; 37 register struct uio *uio; 38 int ioflag; 39 struct ucred *cred; 40 { 41 register struct nfsnode *np = VTONFS(vp); 42 register int biosize; 43 struct buf *bp; 44 struct vattr vattr; 45 daddr_t lbn, bn, rablock; 46 int diff, error = 0; 47 long n, on; 48 49 #ifdef lint 50 ioflag = ioflag; 51 #endif /* lint */ 52 if (uio->uio_rw != UIO_READ) 53 panic("nfs_read mode"); 54 if (uio->uio_resid == 0) 55 return (0); 56 if (uio->uio_offset < 0 && vp->v_type != VDIR) 57 return (EINVAL); 58 biosize = VFSTONFS(vp->v_mount)->nm_rsize; 59 /* 60 * If the file's modify time on the server has changed since the 61 * last read rpc or you have written to the file, 62 * you may have lost data cache consistency with the 63 * server, so flush all of the file's data out of the cache. 64 * Then force a getattr rpc to ensure that you have up to date 65 * attributes. 66 * NB: This implies that cache data can be read when up to 67 * NFS_ATTRTIMEO seconds out of date. If you find that you need current 68 * attributes this could be forced by setting n_attrstamp to 0 before 69 * the nfs_dogetattr() call. 70 */ 71 if (vp->v_type != VLNK) { 72 if (np->n_flag & NMODIFIED) { 73 np->n_flag &= ~NMODIFIED; 74 vinvalbuf(vp, TRUE); 75 np->n_attrstamp = 0; 76 np->n_direofoffset = 0; 77 if (error = nfs_dogetattr(vp, &vattr, cred, 1)) 78 return (error); 79 np->n_mtime = vattr.va_mtime.tv_sec; 80 } else { 81 if (error = nfs_dogetattr(vp, &vattr, cred, 1)) 82 return (error); 83 if (np->n_mtime != vattr.va_mtime.tv_sec) { 84 np->n_direofoffset = 0; 85 vinvalbuf(vp, TRUE); 86 np->n_mtime = vattr.va_mtime.tv_sec; 87 } 88 } 89 } 90 do { 91 switch (vp->v_type) { 92 case VREG: 93 nfsstats.biocache_reads++; 94 lbn = uio->uio_offset / biosize; 95 on = uio->uio_offset & (biosize-1); 96 n = MIN((unsigned)(biosize - on), uio->uio_resid); 97 diff = np->n_size - uio->uio_offset; 98 if (diff <= 0) 99 return (error); 100 if (diff < n) 101 n = diff; 102 bn = lbn*(biosize/DEV_BSIZE); 103 rablock = (lbn+1)*(biosize/DEV_BSIZE); 104 if (vp->v_lastr + 1 == lbn && 105 np->n_size > (rablock * DEV_BSIZE)) 106 error = breada(vp, bn, biosize, rablock, biosize, 107 cred, &bp); 108 else 109 error = bread(vp, bn, biosize, cred, &bp); 110 vp->v_lastr = lbn; 111 if (bp->b_resid) { 112 diff = (on >= (biosize-bp->b_resid)) ? 0 : 113 (biosize-bp->b_resid-on); 114 n = MIN(n, diff); 115 } 116 break; 117 case VLNK: 118 nfsstats.biocache_readlinks++; 119 on = 0; 120 error = bread(vp, (daddr_t)0, NFS_MAXPATHLEN, cred, &bp); 121 n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); 122 break; 123 case VDIR: 124 nfsstats.biocache_readdirs++; 125 on = 0; 126 error = bread(vp, uio->uio_offset, DIRBLKSIZ, cred, &bp); 127 n = MIN(uio->uio_resid, DIRBLKSIZ - bp->b_resid); 128 break; 129 }; 130 if (error) { 131 brelse(bp); 132 return (error); 133 } 134 if (n > 0) 135 error = uiomove(bp->b_un.b_addr + on, (int)n, uio); 136 switch (vp->v_type) { 137 case VREG: 138 if (n+on == biosize || uio->uio_offset == np->n_size) 139 bp->b_flags |= B_AGE; 140 break; 141 case VLNK: 142 n = 0; 143 break; 144 case VDIR: 145 uio->uio_offset = bp->b_blkno; 146 break; 147 }; 148 brelse(bp); 149 } while (error == 0 && uio->uio_resid > 0 && n != 0); 150 return (error); 151 } 152 153 /* 154 * Vnode op for write using bio 155 */ 156 nfs_write(vp, uio, ioflag, cred) 157 register struct vnode *vp; 158 register struct uio *uio; 159 int ioflag; 160 struct ucred *cred; 161 { 162 struct proc *p = curproc; /* XXX */ 163 register int biosize; 164 struct buf *bp; 165 struct nfsnode *np = VTONFS(vp); 166 struct vattr vattr; 167 daddr_t lbn, bn; 168 int n, on, error = 0; 169 170 if (uio->uio_rw != UIO_WRITE) 171 panic("nfs_write mode"); 172 if (vp->v_type != VREG) 173 return (EIO); 174 /* Should we try and do this ?? */ 175 if (ioflag & (IO_APPEND | IO_SYNC)) { 176 if (np->n_flag & NMODIFIED) { 177 np->n_flag &= ~NMODIFIED; 178 vinvalbuf(vp, TRUE); 179 } 180 if (ioflag & IO_APPEND) { 181 np->n_attrstamp = 0; 182 if (error = nfs_dogetattr(vp, &vattr, cred, 1)) 183 return (error); 184 uio->uio_offset = np->n_size; 185 } 186 return (nfs_writerpc(vp, uio, cred, p)); 187 } 188 #ifdef notdef 189 cnt = uio->uio_resid; 190 osize = np->n_size; 191 #endif 192 if (uio->uio_offset < 0) 193 return (EINVAL); 194 if (uio->uio_resid == 0) 195 return (0); 196 /* 197 * Maybe this should be above the vnode op call, but so long as 198 * file servers have no limits, i don't think it matters 199 */ 200 if (uio->uio_offset + uio->uio_resid > 201 p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { 202 psignal(p, SIGXFSZ); 203 return (EFBIG); 204 } 205 /* 206 * I use nm_rsize, not nm_wsize so that all buffer cache blocks 207 * will be the same size within a filesystem. nfs_writerpc will 208 * still use nm_wsize when sizing the rpc's. 209 */ 210 biosize = VFSTONFS(vp->v_mount)->nm_rsize; 211 np->n_flag |= NMODIFIED; 212 do { 213 nfsstats.biocache_writes++; 214 lbn = uio->uio_offset / biosize; 215 on = uio->uio_offset & (biosize-1); 216 n = MIN((unsigned)(biosize - on), uio->uio_resid); 217 if (uio->uio_offset+n > np->n_size) { 218 np->n_size = uio->uio_offset+n; 219 vnode_pager_setsize(vp, np->n_size); 220 } 221 bn = lbn*(biosize/DEV_BSIZE); 222 again: 223 bp = getblk(vp, bn, biosize); 224 if (bp->b_wcred == NOCRED) { 225 crhold(cred); 226 bp->b_wcred = cred; 227 } 228 if (bp->b_dirtyend > 0) { 229 /* 230 * If the new write will leave a contiguous dirty 231 * area, just update the b_dirtyoff and b_dirtyend, 232 * otherwise force a write rpc of the old dirty area. 233 */ 234 if (on <= bp->b_dirtyend && (on+n) >= bp->b_dirtyoff) { 235 bp->b_dirtyoff = MIN(on, bp->b_dirtyoff); 236 bp->b_dirtyend = MAX((on+n), bp->b_dirtyend); 237 } else { 238 bp->b_proc = p; 239 if (error = bwrite(bp)) 240 return (error); 241 goto again; 242 } 243 } else { 244 bp->b_dirtyoff = on; 245 bp->b_dirtyend = on+n; 246 } 247 if (error = uiomove(bp->b_un.b_addr + on, n, uio)) { 248 brelse(bp); 249 return (error); 250 } 251 if ((n+on) == biosize) { 252 bp->b_flags |= B_AGE; 253 bp->b_proc = (struct proc *)0; 254 bawrite(bp); 255 } else { 256 bp->b_proc = (struct proc *)0; 257 bdwrite(bp); 258 } 259 } while (error == 0 && uio->uio_resid > 0 && n != 0); 260 #ifdef notdef 261 /* Should we try and do this for nfs ?? */ 262 if (error && (ioflag & IO_UNIT)) { 263 np->n_size = osize; 264 uio->uio_offset -= cnt - uio->uio_resid; 265 uio->uio_resid = cnt; 266 } 267 #endif 268 return (error); 269 } 270