/*- * Copyright (c) 1982, 1986, 1989, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)vfs_vnops.c 8.2 (Berkeley) 1/21/94 */ #include __FBSDID("$FreeBSD$"); #include "opt_mac.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static fo_rdwr_t vn_read; static fo_rdwr_t vn_write; static fo_ioctl_t vn_ioctl; static fo_poll_t vn_poll; static fo_kqfilter_t vn_kqfilter; static fo_stat_t vn_statfile; static fo_close_t vn_closefile; struct fileops vnops = { .fo_read = vn_read, .fo_write = vn_write, .fo_ioctl = vn_ioctl, .fo_poll = vn_poll, .fo_kqfilter = vn_kqfilter, .fo_stat = vn_statfile, .fo_close = vn_closefile, .fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE }; int vn_open(ndp, flagp, cmode, fdidx) struct nameidata *ndp; int *flagp, cmode, fdidx; { struct thread *td = ndp->ni_cnd.cn_thread; return (vn_open_cred(ndp, flagp, cmode, td->td_ucred, fdidx)); } /* * Common code for vnode open operations. * Check permissions, and call the VOP_OPEN or VOP_CREATE routine. * * Note that this does NOT free nameidata for the successful case, * due to the NDINIT being done elsewhere. */ int vn_open_cred(ndp, flagp, cmode, cred, fdidx) struct nameidata *ndp; int *flagp, cmode; struct ucred *cred; int fdidx; { struct vnode *vp; struct mount *mp; struct thread *td = ndp->ni_cnd.cn_thread; struct vattr vat; struct vattr *vap = &vat; int mode, fmode, error; int vfslocked; #ifdef LOOKUP_SHARED int exclusive; /* The current intended lock state */ exclusive = 0; #endif restart: vfslocked = 0; fmode = *flagp; if (fmode & O_CREAT) { ndp->ni_cnd.cn_nameiop = CREATE; ndp->ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF | MPSAFE; if ((fmode & O_EXCL) == 0 && (fmode & O_NOFOLLOW) == 0) ndp->ni_cnd.cn_flags |= FOLLOW; bwillwrite(); if ((error = namei(ndp)) != 0) return (error); vfslocked = (ndp->ni_cnd.cn_flags & GIANTHELD) != 0; ndp->ni_cnd.cn_flags &= ~MPSAFE; if (ndp->ni_vp == NULL) { VATTR_NULL(vap); vap->va_type = VREG; vap->va_mode = cmode; if (fmode & O_EXCL) vap->va_vaflags |= VA_EXCLUSIVE; if (vn_start_write(ndp->ni_dvp, &mp, V_NOWAIT) != 0) { NDFREE(ndp, NDF_ONLY_PNBUF); vput(ndp->ni_dvp); VFS_UNLOCK_GIANT(vfslocked); if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0) return (error); goto restart; } #ifdef MAC error = mac_check_vnode_create(cred, ndp->ni_dvp, &ndp->ni_cnd, vap); if (error == 0) { #endif VOP_LEASE(ndp->ni_dvp, td, cred, LEASE_WRITE); error = VOP_CREATE(ndp->ni_dvp, &ndp->ni_vp, &ndp->ni_cnd, vap); #ifdef MAC } #endif vput(ndp->ni_dvp); vn_finished_write(mp); if (error) { VFS_UNLOCK_GIANT(vfslocked); NDFREE(ndp, NDF_ONLY_PNBUF); return (error); } ASSERT_VOP_UNLOCKED(ndp->ni_dvp, "create"); ASSERT_VOP_LOCKED(ndp->ni_vp, "create"); fmode &= ~O_TRUNC; vp = ndp->ni_vp; #ifdef LOOKUP_SHARED exclusive = 1; #endif } else { if (ndp->ni_dvp == ndp->ni_vp) vrele(ndp->ni_dvp); else vput(ndp->ni_dvp); ndp->ni_dvp = NULL; vp = ndp->ni_vp; if (fmode & O_EXCL) { error = EEXIST; goto bad; } fmode &= ~O_CREAT; } } else { ndp->ni_cnd.cn_nameiop = LOOKUP; #ifdef LOOKUP_SHARED ndp->ni_cnd.cn_flags = ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKSHARED | LOCKLEAF | MPSAFE; #else ndp->ni_cnd.cn_flags = ((fmode & O_NOFOLLOW) ? NOFOLLOW : FOLLOW) | LOCKLEAF | MPSAFE; #endif if ((error = namei(ndp)) != 0) return (error); ndp->ni_cnd.cn_flags &= ~MPSAFE; vfslocked = (ndp->ni_cnd.cn_flags & GIANTHELD) != 0; vp = ndp->ni_vp; } if (vp->v_type == VLNK) { error = EMLINK; goto bad; } if (vp->v_type == VSOCK) { error = EOPNOTSUPP; goto bad; } mode = 0; if (fmode & (FWRITE | O_TRUNC)) { if (vp->v_type == VDIR) { error = EISDIR; goto bad; } mode |= VWRITE; } if (fmode & FREAD) mode |= VREAD; if (fmode & O_APPEND) mode |= VAPPEND; #ifdef MAC error = mac_check_vnode_open(cred, vp, mode); if (error) goto bad; #endif if ((fmode & O_CREAT) == 0) { if (mode & VWRITE) { error = vn_writechk(vp); if (error) goto bad; } if (mode) { error = VOP_ACCESS(vp, mode, cred, td); if (error) goto bad; } } if ((error = VOP_OPEN(vp, fmode, cred, td, fdidx)) != 0) goto bad; if (fmode & FWRITE) vp->v_writecount++; *flagp = fmode; ASSERT_VOP_LOCKED(vp, "vn_open_cred"); if (fdidx == -1) VFS_UNLOCK_GIANT(vfslocked); return (0); bad: NDFREE(ndp, NDF_ONLY_PNBUF); vput(vp); VFS_UNLOCK_GIANT(vfslocked); *flagp = fmode; ndp->ni_vp = NULL; return (error); } /* * Check for write permissions on the specified vnode. * Prototype text segments cannot be written. */ int vn_writechk(vp) register struct vnode *vp; { ASSERT_VOP_LOCKED(vp, "vn_writechk"); /* * If there's shared text associated with * the vnode, try to free it up once. If * we fail, we can't allow writing. */ if (vp->v_vflag & VV_TEXT) return (ETXTBSY); return (0); } /* * Vnode close call */ int vn_close(vp, flags, file_cred, td) register struct vnode *vp; int flags; struct ucred *file_cred; struct thread *td; { struct mount *mp; int error; VFS_ASSERT_GIANT(vp->v_mount); vn_start_write(vp, &mp, V_WAIT); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); if (flags & FWRITE) vp->v_writecount--; error = VOP_CLOSE(vp, flags, file_cred, td); vput(vp); vn_finished_write(mp); return (error); } /* * Sequential heuristic - detect sequential operation */ static __inline int sequential_heuristic(struct uio *uio, struct file *fp) { if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || uio->uio_offset == fp->f_nextoff) { /* * XXX we assume that the filesystem block size is * the default. Not true, but still gives us a pretty * good indicator of how sequential the read operations * are. */ fp->f_seqcount += (uio->uio_resid + BKVASIZE - 1) / BKVASIZE; if (fp->f_seqcount > IO_SEQMAX) fp->f_seqcount = IO_SEQMAX; return(fp->f_seqcount << IO_SEQSHIFT); } /* * Not sequential, quick draw-down of seqcount */ if (fp->f_seqcount > 1) fp->f_seqcount = 1; else fp->f_seqcount = 0; return(0); } /* * Package up an I/O request on a vnode into a uio and do it. */ int vn_rdwr(rw, vp, base, len, offset, segflg, ioflg, active_cred, file_cred, aresid, td) enum uio_rw rw; struct vnode *vp; caddr_t base; int len; off_t offset; enum uio_seg segflg; int ioflg; struct ucred *active_cred; struct ucred *file_cred; int *aresid; struct thread *td; { struct uio auio; struct iovec aiov; struct mount *mp; struct ucred *cred; int error; VFS_ASSERT_GIANT(vp->v_mount); if ((ioflg & IO_NODELOCKED) == 0) { mp = NULL; if (rw == UIO_WRITE) { if (vp->v_type != VCHR && (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) return (error); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); } else { /* * XXX This should be LK_SHARED but I don't trust VFS * enough to leave it like that until it has been * reviewed further. */ vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); } } auio.uio_iov = &aiov; auio.uio_iovcnt = 1; aiov.iov_base = base; aiov.iov_len = len; auio.uio_resid = len; auio.uio_offset = offset; auio.uio_segflg = segflg; auio.uio_rw = rw; auio.uio_td = td; error = 0; #ifdef MAC if ((ioflg & IO_NOMACCHECK) == 0) { if (rw == UIO_READ) error = mac_check_vnode_read(active_cred, file_cred, vp); else error = mac_check_vnode_write(active_cred, file_cred, vp); } #endif if (error == 0) { if (file_cred) cred = file_cred; else cred = active_cred; if (rw == UIO_READ) error = VOP_READ(vp, &auio, ioflg, cred); else error = VOP_WRITE(vp, &auio, ioflg, cred); } if (aresid) *aresid = auio.uio_resid; else if (auio.uio_resid && error == 0) error = EIO; if ((ioflg & IO_NODELOCKED) == 0) { if (rw == UIO_WRITE) vn_finished_write(mp); VOP_UNLOCK(vp, 0, td); } return (error); } /* * Package up an I/O request on a vnode into a uio and do it. The I/O * request is split up into smaller chunks and we try to avoid saturating * the buffer cache while potentially holding a vnode locked, so we * check bwillwrite() before calling vn_rdwr(). We also call uio_yield() * to give other processes a chance to lock the vnode (either other processes * core'ing the same binary, or unrelated processes scanning the directory). */ int vn_rdwr_inchunks(rw, vp, base, len, offset, segflg, ioflg, active_cred, file_cred, aresid, td) enum uio_rw rw; struct vnode *vp; caddr_t base; size_t len; off_t offset; enum uio_seg segflg; int ioflg; struct ucred *active_cred; struct ucred *file_cred; size_t *aresid; struct thread *td; { int error = 0; int iaresid; VFS_ASSERT_GIANT(vp->v_mount); do { int chunk; /* * Force `offset' to a multiple of MAXBSIZE except possibly * for the first chunk, so that filesystems only need to * write full blocks except possibly for the first and last * chunks. */ chunk = MAXBSIZE - (uoff_t)offset % MAXBSIZE; if (chunk > len) chunk = len; if (rw != UIO_READ && vp->v_type == VREG) bwillwrite(); iaresid = 0; error = vn_rdwr(rw, vp, base, chunk, offset, segflg, ioflg, active_cred, file_cred, &iaresid, td); len -= chunk; /* aresid calc already includes length */ if (error) break; offset += chunk; base += chunk; uio_yield(); } while (len); if (aresid) *aresid = len + iaresid; return (error); } /* * File table vnode read routine. */ static int vn_read(fp, uio, active_cred, flags, td) struct file *fp; struct uio *uio; struct ucred *active_cred; struct thread *td; int flags; { struct vnode *vp; int error, ioflag; int vfslocked; KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td)); vp = fp->f_vnode; ioflag = 0; if (fp->f_flag & FNONBLOCK) ioflag |= IO_NDELAY; if (fp->f_flag & O_DIRECT) ioflag |= IO_DIRECT; vfslocked = VFS_LOCK_GIANT(vp->v_mount); VOP_LEASE(vp, td, fp->f_cred, LEASE_READ); /* * According to McKusick the vn lock is protecting f_offset here. * Once this field has it's own lock we can acquire this shared. */ if ((flags & FOF_OFFSET) == 0) { vn_lock(vp, LK_EXCLUSIVE | LK_NOPAUSE | LK_RETRY, td); uio->uio_offset = fp->f_offset; } else vn_lock(vp, LK_SHARED | LK_NOPAUSE | LK_RETRY, td); ioflag |= sequential_heuristic(uio, fp); #ifdef MAC error = mac_check_vnode_read(active_cred, fp->f_cred, vp); if (error == 0) #endif error = VOP_READ(vp, uio, ioflag, fp->f_cred); if ((flags & FOF_OFFSET) == 0) fp->f_offset = uio->uio_offset; fp->f_nextoff = uio->uio_offset; VOP_UNLOCK(vp, 0, td); VFS_UNLOCK_GIANT(vfslocked); return (error); } /* * File table vnode write routine. */ static int vn_write(fp, uio, active_cred, flags, td) struct file *fp; struct uio *uio; struct ucred *active_cred; struct thread *td; int flags; { struct vnode *vp; struct mount *mp; int error, ioflag; int vfslocked; KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td)); vp = fp->f_vnode; vfslocked = VFS_LOCK_GIANT(vp->v_mount); if (vp->v_type == VREG) bwillwrite(); ioflag = IO_UNIT; if (vp->v_type == VREG && (fp->f_flag & O_APPEND)) ioflag |= IO_APPEND; if (fp->f_flag & FNONBLOCK) ioflag |= IO_NDELAY; if (fp->f_flag & O_DIRECT) ioflag |= IO_DIRECT; if ((fp->f_flag & O_FSYNC) || (vp->v_mount && (vp->v_mount->mnt_flag & MNT_SYNCHRONOUS))) ioflag |= IO_SYNC; mp = NULL; if (vp->v_type != VCHR && (error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) goto unlock; VOP_LEASE(vp, td, fp->f_cred, LEASE_WRITE); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); if ((flags & FOF_OFFSET) == 0) uio->uio_offset = fp->f_offset; ioflag |= sequential_heuristic(uio, fp); #ifdef MAC error = mac_check_vnode_write(active_cred, fp->f_cred, vp); if (error == 0) #endif error = VOP_WRITE(vp, uio, ioflag, fp->f_cred); if ((flags & FOF_OFFSET) == 0) fp->f_offset = uio->uio_offset; fp->f_nextoff = uio->uio_offset; VOP_UNLOCK(vp, 0, td); vn_finished_write(mp); unlock: VFS_UNLOCK_GIANT(vfslocked); return (error); } /* * File table vnode stat routine. */ static int vn_statfile(fp, sb, active_cred, td) struct file *fp; struct stat *sb; struct ucred *active_cred; struct thread *td; { struct vnode *vp = fp->f_vnode; int vfslocked; int error; vfslocked = VFS_LOCK_GIANT(vp->v_mount); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); error = vn_stat(vp, sb, active_cred, fp->f_cred, td); VOP_UNLOCK(vp, 0, td); VFS_UNLOCK_GIANT(vfslocked); return (error); } /* * Stat a vnode; implementation for the stat syscall */ int vn_stat(vp, sb, active_cred, file_cred, td) struct vnode *vp; register struct stat *sb; struct ucred *active_cred; struct ucred *file_cred; struct thread *td; { struct vattr vattr; register struct vattr *vap; int error; u_short mode; #ifdef MAC error = mac_check_vnode_stat(active_cred, file_cred, vp); if (error) return (error); #endif vap = &vattr; error = VOP_GETATTR(vp, vap, active_cred, td); if (error) return (error); /* * Zero the spare stat fields */ bzero(sb, sizeof *sb); /* * Copy from vattr table */ if (vap->va_fsid != VNOVAL) sb->st_dev = vap->va_fsid; else sb->st_dev = vp->v_mount->mnt_stat.f_fsid.val[0]; sb->st_ino = vap->va_fileid; mode = vap->va_mode; switch (vap->va_type) { case VREG: mode |= S_IFREG; break; case VDIR: mode |= S_IFDIR; break; case VBLK: mode |= S_IFBLK; break; case VCHR: mode |= S_IFCHR; break; case VLNK: mode |= S_IFLNK; /* This is a cosmetic change, symlinks do not have a mode. */ if (vp->v_mount->mnt_flag & MNT_NOSYMFOLLOW) sb->st_mode &= ~ACCESSPERMS; /* 0000 */ else sb->st_mode |= ACCESSPERMS; /* 0777 */ break; case VSOCK: mode |= S_IFSOCK; break; case VFIFO: mode |= S_IFIFO; break; default: return (EBADF); }; sb->st_mode = mode; sb->st_nlink = vap->va_nlink; sb->st_uid = vap->va_uid; sb->st_gid = vap->va_gid; sb->st_rdev = vap->va_rdev; if (vap->va_size > OFF_MAX) return (EOVERFLOW); sb->st_size = vap->va_size; sb->st_atimespec = vap->va_atime; sb->st_mtimespec = vap->va_mtime; sb->st_ctimespec = vap->va_ctime; sb->st_birthtimespec = vap->va_birthtime; /* * According to www.opengroup.org, the meaning of st_blksize is * "a filesystem-specific preferred I/O block size for this * object. In some filesystem types, this may vary from file * to file" * Default to PAGE_SIZE after much discussion. * XXX: min(PAGE_SIZE, vp->v_bufobj.bo_bsize) may be more correct. */ sb->st_blksize = PAGE_SIZE; sb->st_flags = vap->va_flags; if (suser(td)) sb->st_gen = 0; else sb->st_gen = vap->va_gen; #if (S_BLKSIZE == 512) /* Optimize this case */ sb->st_blocks = vap->va_bytes >> 9; #else sb->st_blocks = vap->va_bytes / S_BLKSIZE; #endif return (0); } /* * File table vnode ioctl routine. */ static int vn_ioctl(fp, com, data, active_cred, td) struct file *fp; u_long com; void *data; struct ucred *active_cred; struct thread *td; { struct vnode *vp = fp->f_vnode; struct vattr vattr; int vfslocked; int error; vfslocked = VFS_LOCK_GIANT(vp->v_mount); error = ENOTTY; switch (vp->v_type) { case VREG: case VDIR: if (com == FIONREAD) { vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); error = VOP_GETATTR(vp, &vattr, active_cred, td); VOP_UNLOCK(vp, 0, td); if (!error) *(int *)data = vattr.va_size - fp->f_offset; } if (com == FIONBIO || com == FIOASYNC) /* XXX */ error = 0; else error = VOP_IOCTL(vp, com, data, fp->f_flag, active_cred, td); break; default: break; } VFS_UNLOCK_GIANT(vfslocked); return (error); } /* * File table vnode poll routine. */ static int vn_poll(fp, events, active_cred, td) struct file *fp; int events; struct ucred *active_cred; struct thread *td; { struct vnode *vp; int error; mtx_lock(&Giant); vp = fp->f_vnode; #ifdef MAC vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); error = mac_check_vnode_poll(active_cred, fp->f_cred, vp); VOP_UNLOCK(vp, 0, td); if (!error) #endif error = VOP_POLL(vp, events, fp->f_cred, td); mtx_unlock(&Giant); return (error); } /* * Check that the vnode is still valid, and if so * acquire requested lock. */ int #ifndef DEBUG_LOCKS vn_lock(vp, flags, td) #else debug_vn_lock(vp, flags, td, filename, line) #endif struct vnode *vp; int flags; struct thread *td; #ifdef DEBUG_LOCKS const char *filename; int line; #endif { int error; do { if ((flags & LK_INTERLOCK) == 0) VI_LOCK(vp); if ((vp->v_iflag & VI_DOOMED) && vp->v_vxthread != td && (flags & LK_NOWAIT)) { VI_UNLOCK(vp); return (ENOENT); } #ifdef DEBUG_LOCKS vp->filename = filename; vp->line = line; #endif /* * lockmgr drops interlock before it will return for * any reason. So force the code above to relock it. */ error = VOP_LOCK(vp, flags | LK_NOPAUSE | LK_INTERLOCK, td); flags &= ~LK_INTERLOCK; /* * Callers specify LK_RETRY if they wish to get dead vnodes. * If RETRY is not set, we return ENOENT instead. */ if (error != 0 && (vp->v_iflag & VI_DOOMED) && vp->v_vxthread != td && (flags & LK_RETRY) == 0) { VOP_UNLOCK(vp, 0, td); error = ENOENT; break; } } while (flags & LK_RETRY && error != 0); return (error); } /* * File table vnode close routine. */ static int vn_closefile(fp, td) struct file *fp; struct thread *td; { struct vnode *vp; struct flock lf; int vfslocked; int error; vp = fp->f_vnode; vfslocked = VFS_LOCK_GIANT(vp->v_mount); if (fp->f_type == DTYPE_VNODE && fp->f_flag & FHASLOCK) { lf.l_whence = SEEK_SET; lf.l_start = 0; lf.l_len = 0; lf.l_type = F_UNLCK; (void) VOP_ADVLOCK(vp, (caddr_t)fp, F_UNLCK, &lf, F_FLOCK); } fp->f_ops = &badfileops; error = vn_close(vp, fp->f_flag, fp->f_cred, td); VFS_UNLOCK_GIANT(vfslocked); return (error); } /* * Preparing to start a filesystem write operation. If the operation is * permitted, then we bump the count of operations in progress and * proceed. If a suspend request is in progress, we wait until the * suspension is over, and then proceed. */ int vn_start_write(vp, mpp, flags) struct vnode *vp; struct mount **mpp; int flags; { struct mount *mp; int error; error = 0; /* * If a vnode is provided, get and return the mount point that * to which it will write. */ if (vp != NULL) { if ((error = VOP_GETWRITEMOUNT(vp, mpp)) != 0) { *mpp = NULL; if (error != EOPNOTSUPP) return (error); return (0); } } if ((mp = *mpp) == NULL) return (0); MNT_ILOCK(mp); /* * Check on status of suspension. */ while ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { if (flags & V_NOWAIT) { error = EWOULDBLOCK; goto unlock; } error = msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | (flags & PCATCH), "suspfs", 0); if (error) goto unlock; } if (flags & V_XSLEEP) goto unlock; mp->mnt_writeopcount++; unlock: MNT_IUNLOCK(mp); return (error); } /* * Secondary suspension. Used by operations such as vop_inactive * routines that are needed by the higher level functions. These * are allowed to proceed until all the higher level functions have * completed (indicated by mnt_writeopcount dropping to zero). At that * time, these operations are halted until the suspension is over. */ int vn_write_suspend_wait(vp, mp, flags) struct vnode *vp; struct mount *mp; int flags; { int error; if (vp != NULL) { if ((error = VOP_GETWRITEMOUNT(vp, &mp)) != 0) { if (error != EOPNOTSUPP) return (error); return (0); } } /* * If we are not suspended or have not yet reached suspended * mode, then let the operation proceed. */ if (mp == NULL) return (0); MNT_ILOCK(mp); if ((mp->mnt_kern_flag & MNTK_SUSPENDED) == 0) { MNT_IUNLOCK(mp); return (0); } if (flags & V_NOWAIT) { MNT_IUNLOCK(mp); return (EWOULDBLOCK); } /* * Wait for the suspension to finish. */ return (msleep(&mp->mnt_flag, MNT_MTX(mp), (PUSER - 1) | (flags & PCATCH) | PDROP, "suspfs", 0)); } /* * Filesystem write operation has completed. If we are suspending and this * operation is the last one, notify the suspender that the suspension is * now in effect. */ void vn_finished_write(mp) struct mount *mp; { if (mp == NULL) return; MNT_ILOCK(mp); mp->mnt_writeopcount--; if (mp->mnt_writeopcount < 0) panic("vn_finished_write: neg cnt"); if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0 && mp->mnt_writeopcount <= 0) wakeup(&mp->mnt_writeopcount); MNT_IUNLOCK(mp); } /* * Request a filesystem to suspend write operations. */ int vfs_write_suspend(mp) struct mount *mp; { struct thread *td = curthread; int error; error = 0; MNT_ILOCK(mp); if (mp->mnt_kern_flag & MNTK_SUSPEND) goto unlock; mp->mnt_kern_flag |= MNTK_SUSPEND; if (mp->mnt_writeopcount > 0) (void) msleep(&mp->mnt_writeopcount, MNT_MTX(mp), (PUSER - 1)|PDROP, "suspwt", 0); else MNT_IUNLOCK(mp); if ((error = VFS_SYNC(mp, MNT_WAIT, td)) != 0) { vfs_write_resume(mp); return (error); } MNT_ILOCK(mp); mp->mnt_kern_flag |= MNTK_SUSPENDED; unlock: MNT_IUNLOCK(mp); return (error); } /* * Request a filesystem to resume write operations. */ void vfs_write_resume(mp) struct mount *mp; { MNT_ILOCK(mp); if ((mp->mnt_kern_flag & MNTK_SUSPEND) != 0) { mp->mnt_kern_flag &= ~(MNTK_SUSPEND | MNTK_SUSPENDED); wakeup(&mp->mnt_writeopcount); wakeup(&mp->mnt_flag); } MNT_IUNLOCK(mp); } /* * Implement kqueues for files by translating it to vnode operation. */ static int vn_kqfilter(struct file *fp, struct knote *kn) { int error; mtx_lock(&Giant); error = VOP_KQFILTER(fp->f_vnode, kn); mtx_unlock(&Giant); return error; } /* * Simplified in-kernel wrapper calls for extended attribute access. * Both calls pass in a NULL credential, authorizing as "kernel" access. * Set IO_NODELOCKED in ioflg if the vnode is already locked. */ int vn_extattr_get(struct vnode *vp, int ioflg, int attrnamespace, const char *attrname, int *buflen, char *buf, struct thread *td) { struct uio auio; struct iovec iov; int error; iov.iov_len = *buflen; iov.iov_base = buf; auio.uio_iov = &iov; auio.uio_iovcnt = 1; auio.uio_rw = UIO_READ; auio.uio_segflg = UIO_SYSSPACE; auio.uio_td = td; auio.uio_offset = 0; auio.uio_resid = *buflen; if ((ioflg & IO_NODELOCKED) == 0) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); /* authorize attribute retrieval as kernel */ error = VOP_GETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, NULL, td); if ((ioflg & IO_NODELOCKED) == 0) VOP_UNLOCK(vp, 0, td); if (error == 0) { *buflen = *buflen - auio.uio_resid; } return (error); } /* * XXX failure mode if partially written? */ int vn_extattr_set(struct vnode *vp, int ioflg, int attrnamespace, const char *attrname, int buflen, char *buf, struct thread *td) { struct uio auio; struct iovec iov; struct mount *mp; int error; iov.iov_len = buflen; iov.iov_base = buf; auio.uio_iov = &iov; auio.uio_iovcnt = 1; auio.uio_rw = UIO_WRITE; auio.uio_segflg = UIO_SYSSPACE; auio.uio_td = td; auio.uio_offset = 0; auio.uio_resid = buflen; if ((ioflg & IO_NODELOCKED) == 0) { if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) return (error); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); } ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); /* authorize attribute setting as kernel */ error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio, NULL, td); if ((ioflg & IO_NODELOCKED) == 0) { vn_finished_write(mp); VOP_UNLOCK(vp, 0, td); } return (error); } int vn_extattr_rm(struct vnode *vp, int ioflg, int attrnamespace, const char *attrname, struct thread *td) { struct mount *mp; int error; if ((ioflg & IO_NODELOCKED) == 0) { if ((error = vn_start_write(vp, &mp, V_WAIT)) != 0) return (error); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); } ASSERT_VOP_LOCKED(vp, "IO_NODELOCKED with no vp lock held"); /* authorize attribute removal as kernel */ error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, NULL, td); if (error == EOPNOTSUPP) error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL, NULL, td); if ((ioflg & IO_NODELOCKED) == 0) { vn_finished_write(mp); VOP_UNLOCK(vp, 0, td); } return (error); }