/* $OpenBSD: nfs_bio.c,v 1.46 2007/06/01 23:47:57 deraadt Exp $ */ /* $NetBSD: nfs_bio.c,v 1.25.4.2 1996/07/08 20:47:04 jtc Exp $ */ /* * Copyright (c) 1989, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Rick Macklem at The University of Guelph. * * 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. * 3. 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. * * @(#)nfs_bio.c 8.9 (Berkeley) 3/30/95 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern struct proc *nfs_iodwant[NFS_MAXASYNCDAEMON]; extern int nfs_numasync; extern struct nfsstats nfsstats; struct nfs_bufqhead nfs_bufq; /* * Vnode op for read using bio * Any similarity to readip() is purely coincidental */ int nfs_bioread(vp, uio, ioflag, cred) struct vnode *vp; struct uio *uio; int ioflag; struct ucred *cred; { struct nfsnode *np = VTONFS(vp); int biosize, diff; struct buf *bp = NULL, *rabp; struct vattr vattr; struct proc *p; struct nfsmount *nmp = VFSTONFS(vp->v_mount); daddr64_t lbn, bn, rabn; caddr_t baddr; int got_buf = 0, nra, error = 0, n = 0, on = 0, not_readin; off_t offdiff; #ifdef DIAGNOSTIC if (uio->uio_rw != UIO_READ) panic("nfs_read mode"); #endif if (uio->uio_resid == 0) return (0); if (uio->uio_offset < 0) return (EINVAL); p = uio->uio_procp; if ((nmp->nm_flag & (NFSMNT_NFSV3 | NFSMNT_GOTFSINFO)) == NFSMNT_NFSV3) (void)nfs_fsinfo(nmp, vp, cred, p); biosize = nmp->nm_rsize; /* * For nfs, cache consistency can only be maintained approximately. * Although RFC1094 does not specify the criteria, the following is * believed to be compatible with the reference port. * For nfs: * If the file's modify time on the server has changed since the * last read rpc or you have written to the file, * you may have lost data cache consistency with the * server, so flush all of the file's data out of the cache. * Then force a getattr rpc to ensure that you have up to date * attributes. * NB: This implies that cache data can be read when up to * NFS_ATTRTIMEO seconds out of date. If you find that you need current * attributes this could be forced by setting n_attrstamp to 0 before * the VOP_GETATTR() call. */ if (np->n_flag & NMODIFIED) { np->n_attrstamp = 0; error = VOP_GETATTR(vp, &vattr, cred, p); if (error) return (error); np->n_mtime = vattr.va_mtime.tv_sec; } else { error = VOP_GETATTR(vp, &vattr, cred, p); if (error) return (error); if (np->n_mtime != vattr.va_mtime.tv_sec) { error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); if (error) return (error); np->n_mtime = vattr.va_mtime.tv_sec; } } /* * update the cache read creds for this vnode */ if (np->n_rcred) crfree(np->n_rcred); np->n_rcred = cred; crhold(cred); do { if ((vp->v_flag & VROOT) && vp->v_type == VLNK) { return (nfs_readlinkrpc(vp, uio, cred)); } baddr = (caddr_t)0; switch (vp->v_type) { case VREG: nfsstats.biocache_reads++; lbn = uio->uio_offset / biosize; on = uio->uio_offset & (biosize - 1); bn = lbn * (biosize / DEV_BSIZE); not_readin = 1; /* * Start the read ahead(s), as required. */ if (nfs_numasync > 0 && nmp->nm_readahead > 0) { for (nra = 0; nra < nmp->nm_readahead && (lbn + 1 + nra) * biosize < np->n_size; nra++) { rabn = (lbn + 1 + nra) * (biosize / DEV_BSIZE); if (!incore(vp, rabn)) { rabp = nfs_getcacheblk(vp, rabn, biosize, p); if (!rabp) return (EINTR); if ((rabp->b_flags & (B_DELWRI | B_DONE)) == 0) { rabp->b_flags |= (B_READ | B_ASYNC); if (nfs_asyncio(rabp)) { rabp->b_flags |= B_INVAL; brelse(rabp); } } else brelse(rabp); } } } /* * If the block is in the cache and has the required data * in a valid region, just copy it out. * Otherwise, get the block and write back/read in, * as required. */ if ((bp = incore(vp, bn)) && (bp->b_flags & (B_BUSY | B_WRITEINPROG)) == (B_BUSY | B_WRITEINPROG)) got_buf = 0; else { again: bp = nfs_getcacheblk(vp, bn, biosize, p); if (!bp) return (EINTR); got_buf = 1; if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0) { bp->b_flags |= B_READ; not_readin = 0; error = nfs_doio(bp, p); if (error) { brelse(bp); return (error); } } } n = min((unsigned)(biosize - on), uio->uio_resid); offdiff = np->n_size - uio->uio_offset; if (offdiff < (off_t)n) n = (int)offdiff; if (not_readin && n > 0) { if (on < bp->b_validoff || (on + n) > bp->b_validend) { if (!got_buf) { bp = nfs_getcacheblk(vp, bn, biosize, p); if (!bp) return (EINTR); got_buf = 1; } bp->b_flags |= B_INVAFTERWRITE; if (bp->b_dirtyend > 0) { if ((bp->b_flags & B_DELWRI) == 0) panic("nfsbioread"); if (VOP_BWRITE(bp) == EINTR) return (EINTR); } else brelse(bp); goto again; } } diff = (on >= bp->b_validend) ? 0 : (bp->b_validend - on); if (diff < n) n = diff; break; case VLNK: nfsstats.biocache_readlinks++; bp = nfs_getcacheblk(vp, 0, NFS_MAXPATHLEN, p); if (!bp) return (EINTR); if ((bp->b_flags & B_DONE) == 0) { bp->b_flags |= B_READ; error = nfs_doio(bp, p); if (error) { brelse(bp); return (error); } } n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); got_buf = 1; on = 0; break; default: printf(" nfsbioread: type %x unexpected\n",vp->v_type); break; } if (n > 0) { if (!baddr) baddr = bp->b_data; error = uiomove(baddr + on, (int)n, uio); } switch (vp->v_type) { case VREG: break; case VLNK: n = 0; break; default: printf(" nfsbioread: type %x unexpected\n",vp->v_type); } if (got_buf) brelse(bp); } while (error == 0 && uio->uio_resid > 0 && n > 0); return (error); } /* * Vnode op for write using bio */ int nfs_write(v) void *v; { struct vop_write_args *ap = v; int biosize; struct uio *uio = ap->a_uio; struct proc *p = uio->uio_procp; struct vnode *vp = ap->a_vp; struct nfsnode *np = VTONFS(vp); struct ucred *cred = ap->a_cred; int ioflag = ap->a_ioflag; struct buf *bp; struct vattr vattr; struct nfsmount *nmp = VFSTONFS(vp->v_mount); daddr64_t lbn, bn; int n, on, error = 0, extended = 0, wrotedta = 0, truncated = 0; #ifdef DIAGNOSTIC if (uio->uio_rw != UIO_WRITE) panic("nfs_write mode"); if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc) panic("nfs_write proc"); #endif if (vp->v_type != VREG) return (EIO); if (np->n_flag & NWRITEERR) { np->n_flag &= ~NWRITEERR; return (np->n_error); } if ((nmp->nm_flag & (NFSMNT_NFSV3 | NFSMNT_GOTFSINFO)) == NFSMNT_NFSV3) (void)nfs_fsinfo(nmp, vp, cred, p); if (ioflag & (IO_APPEND | IO_SYNC)) { if (np->n_flag & NMODIFIED) { np->n_attrstamp = 0; error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); if (error) return (error); } if (ioflag & IO_APPEND) { np->n_attrstamp = 0; error = VOP_GETATTR(vp, &vattr, cred, p); if (error) return (error); uio->uio_offset = np->n_size; } } if (uio->uio_offset < 0) return (EINVAL); if (uio->uio_resid == 0) return (0); /* * Maybe this should be above the vnode op call, but so long as * file servers have no limits, i don't think it matters */ if (p && uio->uio_offset + uio->uio_resid > p->p_rlimit[RLIMIT_FSIZE].rlim_cur) { psignal(p, SIGXFSZ); return (EFBIG); } /* * update the cache write creds for this node. */ if (np->n_wcred) crfree(np->n_wcred); np->n_wcred = cred; crhold(cred); /* * I use nm_rsize, not nm_wsize so that all buffer cache blocks * will be the same size within a filesystem. nfs_writerpc will * still use nm_wsize when sizing the rpc's. */ biosize = nmp->nm_rsize; do { /* * XXX make sure we aren't cached in the VM page cache */ uvm_vnp_uncache(vp); nfsstats.biocache_writes++; lbn = uio->uio_offset / biosize; on = uio->uio_offset & (biosize-1); n = min((unsigned)(biosize - on), uio->uio_resid); bn = lbn * (biosize / DEV_BSIZE); again: bp = nfs_getcacheblk(vp, bn, biosize, p); if (!bp) return (EINTR); np->n_flag |= NMODIFIED; if (uio->uio_offset + n > np->n_size) { np->n_size = uio->uio_offset + n; uvm_vnp_setsize(vp, (u_long)np->n_size); extended = 1; } else if (uio->uio_offset + n < np->n_size) truncated = 1; /* * If the new write will leave a contiguous dirty * area, just update the b_dirtyoff and b_dirtyend, * otherwise force a write rpc of the old dirty area. */ if (bp->b_dirtyend > 0 && (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { bp->b_proc = p; if (VOP_BWRITE(bp) == EINTR) return (EINTR); goto again; } error = uiomove((char *)bp->b_data + on, n, uio); if (error) { bp->b_flags |= B_ERROR; brelse(bp); return (error); } if (bp->b_dirtyend > 0) { bp->b_dirtyoff = min(on, bp->b_dirtyoff); bp->b_dirtyend = max((on + n), bp->b_dirtyend); } else { bp->b_dirtyoff = on; bp->b_dirtyend = on + n; } if (bp->b_validend == 0 || bp->b_validend < bp->b_dirtyoff || bp->b_validoff > bp->b_dirtyend) { bp->b_validoff = bp->b_dirtyoff; bp->b_validend = bp->b_dirtyend; } else { bp->b_validoff = min(bp->b_validoff, bp->b_dirtyoff); bp->b_validend = max(bp->b_validend, bp->b_dirtyend); } wrotedta = 1; /* * Since this block is being modified, it must be written * again and not just committed. */ if (NFS_ISV3(vp)) { rw_enter_write(&np->n_commitlock); if (bp->b_flags & B_NEEDCOMMIT) { bp->b_flags &= ~B_NEEDCOMMIT; nfs_del_tobecommitted_range(vp, bp); } nfs_del_committed_range(vp, bp); rw_exit_write(&np->n_commitlock); } else bp->b_flags &= ~B_NEEDCOMMIT; /* * If the lease is non-cachable or IO_SYNC do bwrite(). */ if (ioflag & IO_SYNC) { bp->b_proc = p; error = VOP_BWRITE(bp); if (error) return (error); } else if ((n + on) == biosize) { bp->b_proc = (struct proc *)0; bp->b_flags |= B_ASYNC; (void)nfs_writebp(bp, 0); } else { bdwrite(bp); } } while (uio->uio_resid > 0 && n > 0); if (wrotedta) VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0) | (truncated ? NOTE_TRUNCATE : 0)); return (0); } /* * Get an nfs cache block. * Allocate a new one if the block isn't currently in the cache * and return the block marked busy. If the calling process is * interrupted by a signal for an interruptible mount point, return * NULL. */ struct buf * nfs_getcacheblk(vp, bn, size, p) struct vnode *vp; daddr64_t bn; int size; struct proc *p; { struct buf *bp; struct nfsmount *nmp = VFSTONFS(vp->v_mount); if (nmp->nm_flag & NFSMNT_INT) { bp = getblk(vp, bn, size, PCATCH, 0); while (bp == (struct buf *)0) { if (nfs_sigintr(nmp, (struct nfsreq *)0, p)) return ((struct buf *)0); bp = getblk(vp, bn, size, 0, 2 * hz); } } else bp = getblk(vp, bn, size, 0, 0); return (bp); } /* * Flush and invalidate all dirty buffers. If another process is already * doing the flush, just wait for completion. */ int nfs_vinvalbuf(vp, flags, cred, p, intrflg) struct vnode *vp; int flags; struct ucred *cred; struct proc *p; int intrflg; { struct nfsnode *np = VTONFS(vp); struct nfsmount *nmp = VFSTONFS(vp->v_mount); int error = 0, slpflag, slptimeo; if ((nmp->nm_flag & NFSMNT_INT) == 0) intrflg = 0; if (intrflg) { slpflag = PCATCH; slptimeo = 2 * hz; } else { slpflag = 0; slptimeo = 0; } /* * First wait for any other process doing a flush to complete. */ while (np->n_flag & NFLUSHINPROG) { np->n_flag |= NFLUSHWANT; error = tsleep((caddr_t)&np->n_flag, PRIBIO + 2, "nfsvinval", slptimeo); if (error && intrflg && nfs_sigintr(nmp, (struct nfsreq *)0, p)) return (EINTR); } /* * Now, flush as required. */ np->n_flag |= NFLUSHINPROG; error = vinvalbuf(vp, flags, cred, p, slpflag, 0); while (error) { if (intrflg && nfs_sigintr(nmp, (struct nfsreq *)0, p)) { np->n_flag &= ~NFLUSHINPROG; if (np->n_flag & NFLUSHWANT) { np->n_flag &= ~NFLUSHWANT; wakeup((caddr_t)&np->n_flag); } return (EINTR); } error = vinvalbuf(vp, flags, cred, p, 0, slptimeo); } np->n_flag &= ~(NMODIFIED | NFLUSHINPROG); if (np->n_flag & NFLUSHWANT) { np->n_flag &= ~NFLUSHWANT; wakeup((caddr_t)&np->n_flag); } return (0); } /* * Initiate asynchronous I/O. Return an error if no nfsiods are available. * This is mainly to avoid queueing async I/O requests when the nfsiods * are all hung on a dead server. */ int nfs_asyncio(bp) struct buf *bp; { int i,s; if (nfs_numasync == 0) return (EIO); for (i = 0; i < NFS_MAXASYNCDAEMON; i++) if (nfs_iodwant[i]) { if ((bp->b_flags & B_READ) == 0) { bp->b_flags |= B_WRITEINPROG; } TAILQ_INSERT_TAIL(&nfs_bufq, bp, b_freelist); nfs_iodwant[i] = (struct proc *)0; wakeup((caddr_t)&nfs_iodwant[i]); return (0); } /* * If it is a read or a write already marked B_WRITEINPROG or B_NOCACHE * return EIO so the process will call nfs_doio() and do it * synchronously. */ if (bp->b_flags & (B_READ | B_WRITEINPROG | B_NOCACHE)) return (EIO); /* * Just turn the async write into a delayed write, instead of * doing in synchronously. Hopefully, at least one of the nfsiods * is currently doing a write for this file and will pick up the * delayed writes before going back to sleep. */ s = splbio(); buf_dirty(bp); biodone(bp); splx(s); return (0); } /* * Do an I/O operation to/from a cache block. This may be called * synchronously or from an nfsiod. */ int nfs_doio(bp, p) struct buf *bp; struct proc *p; { struct uio *uiop; struct vnode *vp; struct nfsnode *np; struct nfsmount *nmp; int s, error = 0, diff, len, iomode, must_commit = 0; struct uio uio; struct iovec io; vp = bp->b_vp; np = VTONFS(vp); nmp = VFSTONFS(vp->v_mount); uiop = &uio; uiop->uio_iov = &io; uiop->uio_iovcnt = 1; uiop->uio_segflg = UIO_SYSSPACE; uiop->uio_procp = p; /* * Historically, paging was done with physio, but no more... */ if (bp->b_flags & B_PHYS) { /* * ...though reading /dev/drum still gets us here. */ io.iov_len = uiop->uio_resid = bp->b_bcount; /* mapping was done by vmapbuf() */ io.iov_base = bp->b_data; uiop->uio_offset = ((off_t)bp->b_blkno) << DEV_BSHIFT; if (bp->b_flags & B_READ) { uiop->uio_rw = UIO_READ; nfsstats.read_physios++; error = nfs_readrpc(vp, uiop); } else { iomode = NFSV3WRITE_DATASYNC; uiop->uio_rw = UIO_WRITE; nfsstats.write_physios++; error = nfs_writerpc(vp, uiop, &iomode, &must_commit); } if (error) { bp->b_flags |= B_ERROR; bp->b_error = error; } } else if (bp->b_flags & B_READ) { io.iov_len = uiop->uio_resid = bp->b_bcount; io.iov_base = bp->b_data; uiop->uio_rw = UIO_READ; switch (vp->v_type) { case VREG: uiop->uio_offset = ((off_t)bp->b_blkno) << DEV_BSHIFT; nfsstats.read_bios++; error = nfs_readrpc(vp, uiop); if (!error) { bp->b_validoff = 0; if (uiop->uio_resid) { /* * If len > 0, there is a hole in the file and * no writes after the hole have been pushed to * the server yet. * Just zero fill the rest of the valid area. */ diff = bp->b_bcount - uiop->uio_resid; len = np->n_size - ((((off_t)bp->b_blkno) << DEV_BSHIFT) + diff); if (len > 0) { len = min(len, uiop->uio_resid); bzero((char *)bp->b_data + diff, len); bp->b_validend = diff + len; } else bp->b_validend = diff; } else bp->b_validend = bp->b_bcount; } if (p && (vp->v_flag & VTEXT) && (np->n_mtime != np->n_vattr.va_mtime.tv_sec)) { uprintf("Process killed due to text file modification\n"); psignal(p, SIGKILL); } break; case VLNK: uiop->uio_offset = (off_t)0; nfsstats.readlink_bios++; error = nfs_readlinkrpc(vp, uiop, curproc->p_ucred); break; default: printf("nfs_doio: type %x unexpected\n", vp->v_type); break; }; if (error) { bp->b_flags |= B_ERROR; bp->b_error = error; } } else { io.iov_len = uiop->uio_resid = bp->b_dirtyend - bp->b_dirtyoff; uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; io.iov_base = (char *)bp->b_data + bp->b_dirtyoff; uiop->uio_rw = UIO_WRITE; nfsstats.write_bios++; if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE)) == B_ASYNC) iomode = NFSV3WRITE_UNSTABLE; else iomode = NFSV3WRITE_FILESYNC; bp->b_flags |= B_WRITEINPROG; error = nfs_writerpc(vp, uiop, &iomode, &must_commit); rw_enter_write(&np->n_commitlock); if (!error && iomode == NFSV3WRITE_UNSTABLE) { bp->b_flags |= B_NEEDCOMMIT; nfs_add_tobecommitted_range(vp, bp); } else { bp->b_flags &= ~B_NEEDCOMMIT; nfs_del_committed_range(vp, bp); } rw_exit_write(&np->n_commitlock); bp->b_flags &= ~B_WRITEINPROG; /* * For an interrupted write, the buffer is still valid and the * write hasn't been pushed to the server yet, so we can't set * B_ERROR and report the interruption by setting B_EINTR. For * the B_ASYNC case, B_EINTR is not relevant, so the rpc attempt * is essentially a noop. * For the case of a V3 write rpc not being committed to stable * storage, the block is still dirty and requires either a commit * rpc or another write rpc with iomode == NFSV3WRITE_FILESYNC * before the block is reused. This is indicated by setting the * B_DELWRI and B_NEEDCOMMIT flags. */ if (error == EINTR || (!error && (bp->b_flags & B_NEEDCOMMIT))) { s = splbio(); buf_dirty(bp); splx(s); if (!(bp->b_flags & B_ASYNC) && error) bp->b_flags |= B_EINTR; } else { if (error) { bp->b_flags |= B_ERROR; bp->b_error = np->n_error = error; np->n_flag |= NWRITEERR; } bp->b_dirtyoff = bp->b_dirtyend = 0; } } bp->b_resid = uiop->uio_resid; if (must_commit) nfs_clearcommit(vp->v_mount); s = splbio(); biodone(bp); splx(s); return (error); }