Annotation of sys/kern/vfs_vnops.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: vfs_vnops.c,v 1.58 2007/06/14 20:36:34 otto Exp $ */
! 2: /* $NetBSD: vfs_vnops.c,v 1.20 1996/02/04 02:18:41 christos Exp $ */
! 3:
! 4: /*
! 5: * Copyright (c) 1982, 1986, 1989, 1993
! 6: * The Regents of the University of California. All rights reserved.
! 7: * (c) UNIX System Laboratories, Inc.
! 8: * All or some portions of this file are derived from material licensed
! 9: * to the University of California by American Telephone and Telegraph
! 10: * Co. or Unix System Laboratories, Inc. and are reproduced herein with
! 11: * the permission of UNIX System Laboratories, Inc.
! 12: *
! 13: * Redistribution and use in source and binary forms, with or without
! 14: * modification, are permitted provided that the following conditions
! 15: * are met:
! 16: * 1. Redistributions of source code must retain the above copyright
! 17: * notice, this list of conditions and the following disclaimer.
! 18: * 2. Redistributions in binary form must reproduce the above copyright
! 19: * notice, this list of conditions and the following disclaimer in the
! 20: * documentation and/or other materials provided with the distribution.
! 21: * 3. Neither the name of the University nor the names of its contributors
! 22: * may be used to endorse or promote products derived from this software
! 23: * without specific prior written permission.
! 24: *
! 25: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 26: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 27: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 28: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 29: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 30: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 31: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 32: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 33: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 34: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 35: * SUCH DAMAGE.
! 36: *
! 37: * @(#)vfs_vnops.c 8.5 (Berkeley) 12/8/94
! 38: */
! 39:
! 40: #include <sys/param.h>
! 41: #include <sys/systm.h>
! 42: #include <sys/kernel.h>
! 43: #include <sys/malloc.h>
! 44: #include <sys/file.h>
! 45: #include <sys/stat.h>
! 46: #include <sys/buf.h>
! 47: #include <sys/proc.h>
! 48: #include <sys/mount.h>
! 49: #include <sys/namei.h>
! 50: #include <sys/vnode.h>
! 51: #include <sys/ioctl.h>
! 52: #include <sys/tty.h>
! 53: #include <sys/cdio.h>
! 54: #include <sys/poll.h>
! 55:
! 56: #include <uvm/uvm_extern.h>
! 57: #include <miscfs/specfs/specdev.h>
! 58:
! 59: int vn_read(struct file *, off_t *, struct uio *, struct ucred *);
! 60: int vn_write(struct file *, off_t *, struct uio *, struct ucred *);
! 61: int vn_poll(struct file *, int, struct proc *);
! 62: int vn_kqfilter(struct file *, struct knote *);
! 63: int vn_closefile(struct file *, struct proc *);
! 64:
! 65: struct fileops vnops =
! 66: { vn_read, vn_write, vn_ioctl, vn_poll, vn_kqfilter, vn_statfile,
! 67: vn_closefile };
! 68:
! 69: /*
! 70: * Common code for vnode open operations.
! 71: * Check permissions, and call the VOP_OPEN or VOP_CREATE routine.
! 72: */
! 73: int
! 74: vn_open(struct nameidata *ndp, int fmode, int cmode)
! 75: {
! 76: struct vnode *vp;
! 77: struct proc *p = ndp->ni_cnd.cn_proc;
! 78: struct ucred *cred = p->p_ucred;
! 79: struct vattr va;
! 80: int error;
! 81:
! 82: if ((fmode & (FREAD|FWRITE)) == 0)
! 83: return (EINVAL);
! 84: if ((fmode & (O_TRUNC | FWRITE)) == O_TRUNC)
! 85: return (EINVAL);
! 86: if (fmode & O_CREAT) {
! 87: ndp->ni_cnd.cn_nameiop = CREATE;
! 88: ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF;
! 89: if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0)
! 90: ndp->ni_cnd.cn_flags |= FOLLOW;
! 91: if ((error = namei(ndp)) != 0)
! 92: return (error);
! 93:
! 94: if (ndp->ni_vp == NULL) {
! 95: VATTR_NULL(&va);
! 96: va.va_type = VREG;
! 97: va.va_mode = cmode;
! 98: error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp,
! 99: &ndp->ni_cnd, &va);
! 100: if (error)
! 101: return (error);
! 102: fmode &= ~O_TRUNC;
! 103: vp = ndp->ni_vp;
! 104: } else {
! 105: VOP_ABORTOP(ndp->ni_dvp, &ndp->ni_cnd);
! 106: if (ndp->ni_dvp == ndp->ni_vp)
! 107: vrele(ndp->ni_dvp);
! 108: else
! 109: vput(ndp->ni_dvp);
! 110: ndp->ni_dvp = NULL;
! 111: vp = ndp->ni_vp;
! 112: if (fmode & O_EXCL) {
! 113: error = EEXIST;
! 114: goto bad;
! 115: }
! 116: fmode &= ~O_CREAT;
! 117: }
! 118: } else {
! 119: ndp->ni_cnd.cn_nameiop = LOOKUP;
! 120: ndp->ni_cnd.cn_flags =
! 121: ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF;
! 122: if ((error = namei(ndp)) != 0)
! 123: return (error);
! 124: vp = ndp->ni_vp;
! 125: }
! 126: if (vp->v_type == VSOCK) {
! 127: error = EOPNOTSUPP;
! 128: goto bad;
! 129: }
! 130: if (vp->v_type == VLNK) {
! 131: error = EMLINK;
! 132: goto bad;
! 133: }
! 134: if ((fmode & O_CREAT) == 0) {
! 135: if (fmode & FREAD) {
! 136: if ((error = VOP_ACCESS(vp, VREAD, cred, p)) != 0)
! 137: goto bad;
! 138: }
! 139: if (fmode & FWRITE) {
! 140: if (vp->v_type == VDIR) {
! 141: error = EISDIR;
! 142: goto bad;
! 143: }
! 144: if ((error = vn_writechk(vp)) != 0 ||
! 145: (error = VOP_ACCESS(vp, VWRITE, cred, p)) != 0)
! 146: goto bad;
! 147: }
! 148: }
! 149: if ((fmode & O_TRUNC) && vp->v_type == VREG) {
! 150: VATTR_NULL(&va);
! 151: va.va_size = 0;
! 152: if ((error = VOP_SETATTR(vp, &va, cred, p)) != 0)
! 153: goto bad;
! 154: }
! 155: if ((error = VOP_OPEN(vp, fmode, cred, p)) != 0)
! 156: goto bad;
! 157:
! 158: if (vp->v_flag & VCLONED) {
! 159: struct cloneinfo *cip = (struct cloneinfo *) vp->v_data;
! 160:
! 161: vp->v_flag &= ~VCLONED;
! 162: ndp->ni_vp = cip->ci_vp; /* return cloned vnode */
! 163: vp->v_data = cip->ci_data; /* restore v_data */
! 164: VOP_UNLOCK(vp, 0, p); /* keep a reference */
! 165: vp = ndp->ni_vp; /* for the increment below */
! 166:
! 167: free(cip, M_TEMP);
! 168: }
! 169:
! 170: if (fmode & FWRITE)
! 171: vp->v_writecount++;
! 172: return (0);
! 173: bad:
! 174: vput(vp);
! 175: return (error);
! 176: }
! 177:
! 178: /*
! 179: * Check for write permissions on the specified vnode.
! 180: * Prototype text segments cannot be written.
! 181: */
! 182: int
! 183: vn_writechk(struct vnode *vp)
! 184: {
! 185: /*
! 186: * Disallow write attempts on read-only file systems;
! 187: * unless the file is a socket or a block or character
! 188: * device resident on the file system.
! 189: */
! 190: if (vp->v_mount->mnt_flag & MNT_RDONLY) {
! 191: switch (vp->v_type) {
! 192: case VREG:
! 193: case VDIR:
! 194: case VLNK:
! 195: return (EROFS);
! 196: case VNON:
! 197: case VCHR:
! 198: case VSOCK:
! 199: case VFIFO:
! 200: case VBAD:
! 201: case VBLK:
! 202: break;
! 203: }
! 204: }
! 205: /*
! 206: * If there's shared text associated with
! 207: * the vnode, try to free it up once. If
! 208: * we fail, we can't allow writing.
! 209: */
! 210: if ((vp->v_flag & VTEXT) && !uvm_vnp_uncache(vp))
! 211: return (ETXTBSY);
! 212:
! 213: return (0);
! 214: }
! 215:
! 216: /*
! 217: * Mark a vnode as being the text image of a running process.
! 218: */
! 219: void
! 220: vn_marktext(struct vnode *vp)
! 221: {
! 222: vp->v_flag |= VTEXT;
! 223: }
! 224:
! 225: /*
! 226: * Vnode close call
! 227: */
! 228: int
! 229: vn_close(struct vnode *vp, int flags, struct ucred *cred, struct proc *p)
! 230: {
! 231: int error;
! 232:
! 233: if (flags & FWRITE)
! 234: vp->v_writecount--;
! 235: vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
! 236: error = VOP_CLOSE(vp, flags, cred, p);
! 237: vput(vp);
! 238: return (error);
! 239: }
! 240:
! 241: /*
! 242: * Package up an I/O request on a vnode into a uio and do it.
! 243: */
! 244: int
! 245: vn_rdwr(enum uio_rw rw, struct vnode *vp, caddr_t base, int len, off_t offset,
! 246: enum uio_seg segflg, int ioflg, struct ucred *cred, size_t *aresid,
! 247: struct proc *p)
! 248: {
! 249: struct uio auio;
! 250: struct iovec aiov;
! 251: int error;
! 252:
! 253: if ((ioflg & IO_NODELOCKED) == 0)
! 254: vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
! 255: auio.uio_iov = &aiov;
! 256: auio.uio_iovcnt = 1;
! 257: aiov.iov_base = base;
! 258: aiov.iov_len = len;
! 259: auio.uio_resid = len;
! 260: auio.uio_offset = offset;
! 261: auio.uio_segflg = segflg;
! 262: auio.uio_rw = rw;
! 263: auio.uio_procp = p;
! 264: if (rw == UIO_READ) {
! 265: error = VOP_READ(vp, &auio, ioflg, cred);
! 266: } else {
! 267: error = VOP_WRITE(vp, &auio, ioflg, cred);
! 268: }
! 269: if (aresid)
! 270: *aresid = auio.uio_resid;
! 271: else
! 272: if (auio.uio_resid && error == 0)
! 273: error = EIO;
! 274: if ((ioflg & IO_NODELOCKED) == 0)
! 275: VOP_UNLOCK(vp, 0, p);
! 276: return (error);
! 277: }
! 278:
! 279: /*
! 280: * File table vnode read routine.
! 281: */
! 282: int
! 283: vn_read(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred)
! 284: {
! 285: struct vnode *vp = (struct vnode *)fp->f_data;
! 286: int error = 0;
! 287: size_t count;
! 288: struct proc *p = uio->uio_procp;
! 289:
! 290: vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
! 291: uio->uio_offset = *poff;
! 292: count = uio->uio_resid;
! 293: if (vp->v_type != VDIR)
! 294: error = VOP_READ(vp, uio,
! 295: (fp->f_flag & FNONBLOCK) ? IO_NDELAY : 0, cred);
! 296: *poff += count - uio->uio_resid;
! 297: VOP_UNLOCK(vp, 0, p);
! 298: return (error);
! 299: }
! 300:
! 301: /*
! 302: * File table vnode write routine.
! 303: */
! 304: int
! 305: vn_write(struct file *fp, off_t *poff, struct uio *uio, struct ucred *cred)
! 306: {
! 307: struct vnode *vp = (struct vnode *)fp->f_data;
! 308: struct proc *p = uio->uio_procp;
! 309: int error, ioflag = IO_UNIT;
! 310: size_t count;
! 311:
! 312: if (vp->v_type == VREG && (fp->f_flag & O_APPEND))
! 313: ioflag |= IO_APPEND;
! 314: if (fp->f_flag & FNONBLOCK)
! 315: ioflag |= IO_NDELAY;
! 316: if ((fp->f_flag & FFSYNC) ||
! 317: (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS)))
! 318: ioflag |= IO_SYNC;
! 319: vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
! 320: uio->uio_offset = *poff;
! 321: count = uio->uio_resid;
! 322: error = VOP_WRITE(vp, uio, ioflag, cred);
! 323: if (ioflag & IO_APPEND)
! 324: *poff = uio->uio_offset;
! 325: else
! 326: *poff += count - uio->uio_resid;
! 327: VOP_UNLOCK(vp, 0, p);
! 328: return (error);
! 329: }
! 330:
! 331: /*
! 332: * File table wrapper for vn_stat
! 333: */
! 334: int
! 335: vn_statfile(struct file *fp, struct stat *sb, struct proc *p)
! 336: {
! 337: struct vnode *vp = (struct vnode *)fp->f_data;
! 338: return vn_stat(vp, sb, p);
! 339: }
! 340:
! 341: /*
! 342: * vnode stat routine.
! 343: */
! 344: int
! 345: vn_stat(struct vnode *vp, struct stat *sb, struct proc *p)
! 346: {
! 347: struct vattr va;
! 348: int error;
! 349: mode_t mode;
! 350:
! 351: error = VOP_GETATTR(vp, &va, p->p_ucred, p);
! 352: if (error)
! 353: return (error);
! 354: /*
! 355: * Copy from vattr table
! 356: */
! 357: sb->st_dev = va.va_fsid;
! 358: sb->st_ino = va.va_fileid;
! 359: mode = va.va_mode;
! 360: switch (vp->v_type) {
! 361: case VREG:
! 362: mode |= S_IFREG;
! 363: break;
! 364: case VDIR:
! 365: mode |= S_IFDIR;
! 366: break;
! 367: case VBLK:
! 368: mode |= S_IFBLK;
! 369: break;
! 370: case VCHR:
! 371: mode |= S_IFCHR;
! 372: break;
! 373: case VLNK:
! 374: mode |= S_IFLNK;
! 375: break;
! 376: case VSOCK:
! 377: mode |= S_IFSOCK;
! 378: break;
! 379: case VFIFO:
! 380: mode |= S_IFIFO;
! 381: break;
! 382: default:
! 383: return (EBADF);
! 384: }
! 385: sb->st_mode = mode;
! 386: sb->st_nlink = va.va_nlink;
! 387: sb->st_uid = va.va_uid;
! 388: sb->st_gid = va.va_gid;
! 389: sb->st_rdev = va.va_rdev;
! 390: sb->st_size = va.va_size;
! 391: sb->st_atimespec = va.va_atime;
! 392: sb->st_mtimespec = va.va_mtime;
! 393: sb->st_ctimespec = va.va_ctime;
! 394: sb->st_blksize = va.va_blocksize;
! 395: sb->st_flags = va.va_flags;
! 396: sb->st_gen = va.va_gen;
! 397: sb->st_blocks = va.va_bytes / S_BLKSIZE;
! 398: return (0);
! 399: }
! 400:
! 401: /*
! 402: * File table vnode ioctl routine.
! 403: */
! 404: int
! 405: vn_ioctl(struct file *fp, u_long com, caddr_t data, struct proc *p)
! 406: {
! 407: struct vnode *vp = ((struct vnode *)fp->f_data);
! 408: struct vattr vattr;
! 409: int error;
! 410:
! 411: switch (vp->v_type) {
! 412:
! 413: case VREG:
! 414: case VDIR:
! 415: if (com == FIONREAD) {
! 416: error = VOP_GETATTR(vp, &vattr, p->p_ucred, p);
! 417: if (error)
! 418: return (error);
! 419: *(int *)data = vattr.va_size - fp->f_offset;
! 420: return (0);
! 421: }
! 422: if (com == FIONBIO || com == FIOASYNC) /* XXX */
! 423: return (0); /* XXX */
! 424: /* FALLTHROUGH */
! 425: default:
! 426: return (ENOTTY);
! 427:
! 428: case VFIFO:
! 429: case VCHR:
! 430: case VBLK:
! 431: error = VOP_IOCTL(vp, com, data, fp->f_flag, p->p_ucred, p);
! 432: if (error == 0 && com == TIOCSCTTY) {
! 433: if (p->p_session->s_ttyvp)
! 434: vrele(p->p_session->s_ttyvp);
! 435: p->p_session->s_ttyvp = vp;
! 436: VREF(vp);
! 437: }
! 438: return (error);
! 439: }
! 440: }
! 441:
! 442: /*
! 443: * File table vnode poll routine.
! 444: */
! 445: int
! 446: vn_poll(struct file *fp, int events, struct proc *p)
! 447: {
! 448: return (VOP_POLL(((struct vnode *)fp->f_data), events, p));
! 449: }
! 450:
! 451: /*
! 452: * Check that the vnode is still valid, and if so
! 453: * acquire requested lock.
! 454: */
! 455: int
! 456: vn_lock(struct vnode *vp, int flags, struct proc *p)
! 457: {
! 458: int error;
! 459:
! 460: if ((flags & LK_RECURSEFAIL) == 0)
! 461: flags |= LK_CANRECURSE;
! 462:
! 463: do {
! 464: if (vp->v_flag & VXLOCK) {
! 465: vp->v_flag |= VXWANT;
! 466: tsleep(vp, PINOD, "vn_lock", 0);
! 467: error = ENOENT;
! 468: } else {
! 469: error = VOP_LOCK(vp, flags, p);
! 470: if (error == 0)
! 471: return (error);
! 472: }
! 473: } while (flags & LK_RETRY);
! 474: return (error);
! 475: }
! 476:
! 477: /*
! 478: * File table vnode close routine.
! 479: */
! 480: int
! 481: vn_closefile(struct file *fp, struct proc *p)
! 482: {
! 483: return (vn_close(((struct vnode *)fp->f_data), fp->f_flag,
! 484: fp->f_cred, p));
! 485: }
! 486:
! 487: int
! 488: vn_kqfilter(struct file *fp, struct knote *kn)
! 489: {
! 490: return (VOP_KQFILTER(((struct vnode *)fp->f_data), kn));
! 491: }
! 492:
! 493: /*
! 494: * Common code for vnode access operations.
! 495: */
! 496:
! 497: /* Check if a directory can be found inside another in the hierarchy */
! 498: int
! 499: vn_isunder(struct vnode *lvp, struct vnode *rvp, struct proc *p)
! 500: {
! 501: int error;
! 502:
! 503: error = vfs_getcwd_common(lvp, rvp, NULL, NULL, MAXPATHLEN/2, 0, p);
! 504:
! 505: if (!error)
! 506: return (1);
! 507:
! 508: return (0);
! 509: }
CVSweb
![[BACK]](/icons/back.gif){kind=icon}
Return to vfs_vnops.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / sys / kern