/* * 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 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. * * @(#)nfs_bio.c 8.9 (Berkeley) 3/30/95 * $Id: nfs_bio.c,v 1.48 1998/01/31 01:27:18 tegge Exp $ */ #include "opt_diagnostic.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static struct buf *nfs_getcacheblk __P((struct vnode *vp, daddr_t bn, int size, struct proc *p)); extern int nfs_numasync; extern struct nfsstats nfsstats; /* * Vnode op for VM getpages. */ int nfs_getpages(ap) struct vop_getpages_args *ap; { int i, pcount, error; struct uio uio; struct iovec iov; vm_page_t m; vm_offset_t kva; if ((ap->a_vp->v_object) == NULL) { printf("nfs_getpages: called with non-merged cache vnode??\n"); return EOPNOTSUPP; } m = ap->a_m[ap->a_reqpage]; kva = vm_pager_map_page(m); iov.iov_base = (caddr_t) kva; iov.iov_len = PAGE_SIZE; uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = IDX_TO_OFF(m->pindex); uio.uio_resid = PAGE_SIZE; uio.uio_segflg = UIO_SYSSPACE; uio.uio_rw = UIO_READ; uio.uio_procp = curproc; error = nfs_readrpc(ap->a_vp, &uio, curproc->p_ucred); vm_pager_unmap_page(kva); pcount = round_page(ap->a_count) / PAGE_SIZE; for (i = 0; i < pcount; i++) { if (i != ap->a_reqpage) { vnode_pager_freepage(ap->a_m[i]); } } if (error && (uio.uio_resid == PAGE_SIZE)) return VM_PAGER_ERROR; return 0; } /* * Vnode op for read using bio * Any similarity to readip() is purely coincidental */ int nfs_bioread(vp, uio, ioflag, cred, getpages) register struct vnode *vp; register struct uio *uio; int ioflag; struct ucred *cred; int getpages; { register struct nfsnode *np = VTONFS(vp); register int biosize, diff, i; struct buf *bp = 0, *rabp; struct vattr vattr; struct proc *p; struct nfsmount *nmp = VFSTONFS(vp->v_mount); daddr_t lbn, rabn; int bufsize; int nra, error = 0, n = 0, on = 0, not_readin; #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 = vp->v_mount->mnt_stat.f_iosize; /* * 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 nqnfs, full cache consistency is maintained within the loop. * 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 ((nmp->nm_flag & NFSMNT_NQNFS) == 0) { if (np->n_flag & NMODIFIED) { if (vp->v_type != VREG) { if (vp->v_type != VDIR) panic("nfs: bioread, not dir"); nfs_invaldir(vp); error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); if (error) return (error); } 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) { if (vp->v_type == VDIR) nfs_invaldir(vp); error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); if (error) return (error); np->n_mtime = vattr.va_mtime.tv_sec; } } } do { /* * Get a valid lease. If cached data is stale, flush it. */ if (nmp->nm_flag & NFSMNT_NQNFS) { if (NQNFS_CKINVALID(vp, np, ND_READ)) { do { error = nqnfs_getlease(vp, ND_READ, cred, p); } while (error == NQNFS_EXPIRED); if (error) return (error); if (np->n_lrev != np->n_brev || (np->n_flag & NQNFSNONCACHE) || ((np->n_flag & NMODIFIED) && vp->v_type == VDIR)) { if (vp->v_type == VDIR) nfs_invaldir(vp); error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); if (error) return (error); np->n_brev = np->n_lrev; } } else if (vp->v_type == VDIR && (np->n_flag & NMODIFIED)) { nfs_invaldir(vp); error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); if (error) return (error); } } if (np->n_flag & NQNFSNONCACHE) { switch (vp->v_type) { case VREG: return (nfs_readrpc(vp, uio, cred)); case VLNK: return (nfs_readlinkrpc(vp, uio, cred)); case VDIR: break; default: printf(" NQNFSNONCACHE: type %x unexpected\n", vp->v_type); }; } switch (vp->v_type) { case VREG: nfsstats.biocache_reads++; lbn = uio->uio_offset / biosize; on = uio->uio_offset & (biosize - 1); 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 && (off_t)(lbn + 1 + nra) * biosize < np->n_size; nra++) { rabn = lbn + 1 + nra; if (!incore(vp, rabn)) { rabp = nfs_getcacheblk(vp, rabn, biosize, p); if (!rabp) return (EINTR); if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { rabp->b_flags |= (B_READ | B_ASYNC); vfs_busy_pages(rabp, 0); if (nfs_asyncio(rabp, cred)) { rabp->b_flags |= B_INVAL|B_ERROR; vfs_unbusy_pages(rabp); 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. */ again: bufsize = biosize; if ((off_t)(lbn + 1) * biosize > np->n_size && (off_t)(lbn + 1) * biosize - np->n_size < biosize) { bufsize = np->n_size - lbn * biosize; bufsize = (bufsize + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); } bp = nfs_getcacheblk(vp, lbn, bufsize, p); if (!bp) return (EINTR); /* * If we are being called from nfs_getpages, we must * make sure the buffer is a vmio buffer. The vp will * already be setup for vmio but there may be some old * non-vmio buffers attached to it. */ if (getpages && !(bp->b_flags & B_VMIO)) { #ifdef DIAGNOSTIC printf("nfs_bioread: non vmio buf found, discarding\n"); #endif bp->b_flags |= B_NOCACHE; 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; } if ((bp->b_flags & B_CACHE) == 0) { bp->b_flags |= B_READ; bp->b_flags &= ~(B_DONE | B_ERROR | B_INVAL); not_readin = 0; vfs_busy_pages(bp, 0); error = nfs_doio(bp, cred, p); if (error) { brelse(bp); return (error); } } if (bufsize > on) { n = min((unsigned)(bufsize - on), uio->uio_resid); } else { n = 0; } diff = np->n_size - uio->uio_offset; if (diff < n) n = diff; if (not_readin && n > 0) { if (on < bp->b_validoff || (on + n) > bp->b_validend) { bp->b_flags |= B_NOCACHE; 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; } } vp->v_lastr = lbn; 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, (daddr_t)0, NFS_MAXPATHLEN, p); if (!bp) return (EINTR); if ((bp->b_flags & B_CACHE) == 0) { bp->b_flags |= B_READ; vfs_busy_pages(bp, 0); error = nfs_doio(bp, cred, p); if (error) { bp->b_flags |= B_ERROR; brelse(bp); return (error); } } n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid); on = 0; break; case VDIR: nfsstats.biocache_readdirs++; if (np->n_direofoffset && uio->uio_offset >= np->n_direofoffset) { return (0); } lbn = uio->uio_offset / NFS_DIRBLKSIZ; on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, p); if (!bp) return (EINTR); if ((bp->b_flags & B_CACHE) == 0) { bp->b_flags |= B_READ; vfs_busy_pages(bp, 0); error = nfs_doio(bp, cred, p); if (error) { brelse(bp); } while (error == NFSERR_BAD_COOKIE) { nfs_invaldir(vp); error = nfs_vinvalbuf(vp, 0, cred, p, 1); /* * Yuck! The directory has been modified on the * server. The only way to get the block is by * reading from the beginning to get all the * offset cookies. */ for (i = 0; i <= lbn && !error; i++) { if (np->n_direofoffset && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) return (0); bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, p); if (!bp) return (EINTR); if ((bp->b_flags & B_DONE) == 0) { bp->b_flags |= B_READ; vfs_busy_pages(bp, 0); error = nfs_doio(bp, cred, p); if (error) { brelse(bp); } else if (i < lbn) { brelse(bp); } } } } if (error) return (error); } /* * If not eof and read aheads are enabled, start one. * (You need the current block first, so that you have the * directory offset cookie of the next block.) */ if (nfs_numasync > 0 && nmp->nm_readahead > 0 && (np->n_direofoffset == 0 || (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && !(np->n_flag & NQNFSNONCACHE) && !incore(vp, lbn + 1)) { rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, p); if (rabp) { if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { rabp->b_flags |= (B_READ | B_ASYNC); vfs_busy_pages(rabp, 0); if (nfs_asyncio(rabp, cred)) { rabp->b_flags |= B_INVAL|B_ERROR; vfs_unbusy_pages(rabp); brelse(rabp); } } else { brelse(rabp); } } } /* * Make sure we use a signed variant of min() since * the second term may be negative. */ n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); break; default: printf(" nfs_bioread: type %x unexpected\n",vp->v_type); break; }; if (n > 0) { error = uiomove(bp->b_data + on, (int)n, uio); } switch (vp->v_type) { case VREG: break; case VLNK: n = 0; break; case VDIR: if (np->n_flag & NQNFSNONCACHE) bp->b_flags |= B_INVAL; break; default: printf(" nfs_bioread: type %x unexpected\n",vp->v_type); } brelse(bp); } while (error == 0 && uio->uio_resid > 0 && n > 0); return (error); } /* * Vnode op for write using bio */ int nfs_write(ap) struct vop_write_args /* { struct vnode *a_vp; struct uio *a_uio; int a_ioflag; struct ucred *a_cred; } */ *ap; { register int biosize; register struct uio *uio = ap->a_uio; struct proc *p = uio->uio_procp; register struct vnode *vp = ap->a_vp; struct nfsnode *np = VTONFS(vp); register struct ucred *cred = ap->a_cred; int ioflag = ap->a_ioflag; struct buf *bp; struct vattr vattr; struct nfsmount *nmp = VFSTONFS(vp->v_mount); daddr_t lbn; int bufsize; int n, on, error = 0, iomode, must_commit; #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); } /* * 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 = vp->v_mount->mnt_stat.f_iosize; do { /* * Check for a valid write lease. */ if ((nmp->nm_flag & NFSMNT_NQNFS) && NQNFS_CKINVALID(vp, np, ND_WRITE)) { do { error = nqnfs_getlease(vp, ND_WRITE, cred, p); } while (error == NQNFS_EXPIRED); if (error) return (error); if (np->n_lrev != np->n_brev || (np->n_flag & NQNFSNONCACHE)) { error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); if (error) return (error); np->n_brev = np->n_lrev; } } if ((np->n_flag & NQNFSNONCACHE) && uio->uio_iovcnt == 1) { iomode = NFSV3WRITE_FILESYNC; error = nfs_writerpc(vp, uio, cred, &iomode, &must_commit); if (must_commit) nfs_clearcommit(vp->v_mount); return (error); } nfsstats.biocache_writes++; lbn = uio->uio_offset / biosize; on = uio->uio_offset & (biosize-1); n = min((unsigned)(biosize - on), uio->uio_resid); again: if (uio->uio_offset + n > np->n_size) { np->n_size = uio->uio_offset + n; np->n_flag |= NMODIFIED; vnode_pager_setsize(vp, (u_long)np->n_size); } bufsize = biosize; if ((lbn + 1) * biosize > np->n_size) { bufsize = np->n_size - lbn * biosize; bufsize = (bufsize + DEV_BSIZE - 1) & ~(DEV_BSIZE - 1); } bp = nfs_getcacheblk(vp, lbn, bufsize, p); if (!bp) return (EINTR); if (bp->b_wcred == NOCRED) { crhold(cred); bp->b_wcred = cred; } np->n_flag |= NMODIFIED; if ((bp->b_blkno * DEV_BSIZE) + bp->b_dirtyend > np->n_size) { bp->b_dirtyend = np->n_size - (bp->b_blkno * DEV_BSIZE); } /* * 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; } /* * Check for valid write lease and get one as required. * In case getblk() and/or bwrite() delayed us. */ if ((nmp->nm_flag & NFSMNT_NQNFS) && NQNFS_CKINVALID(vp, np, ND_WRITE)) { do { error = nqnfs_getlease(vp, ND_WRITE, cred, p); } while (error == NQNFS_EXPIRED); if (error) { brelse(bp); return (error); } if (np->n_lrev != np->n_brev || (np->n_flag & NQNFSNONCACHE)) { brelse(bp); error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); if (error) return (error); np->n_brev = np->n_lrev; 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); } /* * Since this block is being modified, it must be written * again and not just committed. */ bp->b_flags &= ~B_NEEDCOMMIT; /* * If the lease is non-cachable or IO_SYNC do bwrite(). */ if ((np->n_flag & NQNFSNONCACHE) || (ioflag & IO_SYNC)) { bp->b_proc = p; error = VOP_BWRITE(bp); if (error) return (error); if (np->n_flag & NQNFSNONCACHE) { error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); if (error) return (error); } } else if ((n + on) == biosize && (nmp->nm_flag & NFSMNT_NQNFS) == 0) { 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); 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. */ static struct buf * nfs_getcacheblk(vp, bn, size, p) struct vnode *vp; daddr_t bn; int size; struct proc *p; { register struct buf *bp; struct mount *mp; struct nfsmount *nmp; mp = vp->v_mount; nmp = VFSTONFS(mp); 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); if( vp->v_type == VREG) { int biosize; biosize = mp->mnt_stat.f_iosize; bp->b_blkno = (bn * biosize) / DEV_BSIZE; } 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; { register struct nfsnode *np = VTONFS(vp); struct nfsmount *nmp = VFSTONFS(vp->v_mount); int error = 0, slpflag, slptimeo; if (vp->v_flag & VXLOCK) { return (0); } 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, cred) register struct buf *bp; struct ucred *cred; { struct nfsmount *nmp; int i; int gotiod; int slpflag = 0; int slptimeo = 0; int error; if (nfs_numasync == 0) return (EIO); nmp = VFSTONFS(bp->b_vp->v_mount); again: if (nmp->nm_flag & NFSMNT_INT) slpflag = PCATCH; gotiod = FALSE; /* * Find a free iod to process this request. */ for (i = 0; i < NFS_MAXASYNCDAEMON; i++) if (nfs_iodwant[i]) { /* * Found one, so wake it up and tell it which * mount to process. */ NFS_DPF(ASYNCIO, ("nfs_asyncio: waking iod %d for mount %p\n", i, nmp)); nfs_iodwant[i] = (struct proc *)0; nfs_iodmount[i] = nmp; nmp->nm_bufqiods++; wakeup((caddr_t)&nfs_iodwant[i]); gotiod = TRUE; break; } /* * If none are free, we may already have an iod working on this mount * point. If so, it will process our request. */ if (!gotiod) { if (nmp->nm_bufqiods > 0) { NFS_DPF(ASYNCIO, ("nfs_asyncio: %d iods are already processing mount %p\n", nmp->nm_bufqiods, nmp)); gotiod = TRUE; } } /* * If we have an iod which can process the request, then queue * the buffer. */ if (gotiod) { /* * Ensure that the queue never grows too large. */ while (nmp->nm_bufqlen >= 2*nfs_numasync) { NFS_DPF(ASYNCIO, ("nfs_asyncio: waiting for mount %p queue to drain\n", nmp)); nmp->nm_bufqwant = TRUE; error = tsleep(&nmp->nm_bufq, slpflag | PRIBIO, "nfsaio", slptimeo); if (error) { if (nfs_sigintr(nmp, NULL, bp->b_proc)) return (EINTR); if (slpflag == PCATCH) { slpflag = 0; slptimeo = 2 * hz; } } /* * We might have lost our iod while sleeping, * so check and loop if nescessary. */ if (nmp->nm_bufqiods == 0) { NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp)); goto again; } } if (bp->b_flags & B_READ) { if (bp->b_rcred == NOCRED && cred != NOCRED) { crhold(cred); bp->b_rcred = cred; } } else { bp->b_flags |= B_WRITEINPROG; if (bp->b_wcred == NOCRED && cred != NOCRED) { crhold(cred); bp->b_wcred = cred; } } TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); nmp->nm_bufqlen++; return (0); } /* * All the iods are busy on other mounts, so return EIO to * force the caller to process the i/o synchronously. */ NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n")); return (EIO); } /* * Do an I/O operation to/from a cache block. This may be called * synchronously or from an nfsiod. */ int nfs_doio(bp, cr, p) register struct buf *bp; struct ucred *cr; struct proc *p; { register struct uio *uiop; register struct vnode *vp; struct nfsnode *np; struct nfsmount *nmp; int 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_BSIZE; if (bp->b_flags & B_READ) { uiop->uio_rw = UIO_READ; nfsstats.read_physios++; error = nfs_readrpc(vp, uiop, cr); } else { int com; iomode = NFSV3WRITE_DATASYNC; uiop->uio_rw = UIO_WRITE; nfsstats.write_physios++; error = nfs_writerpc(vp, uiop, cr, &iomode, &com); } 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_BSIZE; nfsstats.read_bios++; error = nfs_readrpc(vp, uiop, cr); 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 - (((u_quad_t)bp->b_blkno) * DEV_BSIZE + 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) && (((nmp->nm_flag & NFSMNT_NQNFS) && NQNFS_CKINVALID(vp, np, ND_READ) && np->n_lrev != np->n_brev) || (!(nmp->nm_flag & NFSMNT_NQNFS) && np->n_mtime != np->n_vattr.va_mtime.tv_sec))) { uprintf("Process killed due to text file modification\n"); psignal(p, SIGKILL); p->p_flag |= P_NOSWAP; } break; case VLNK: uiop->uio_offset = (off_t)0; nfsstats.readlink_bios++; error = nfs_readlinkrpc(vp, uiop, cr); break; case VDIR: nfsstats.readdir_bios++; uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ; if (nmp->nm_flag & NFSMNT_RDIRPLUS) { error = nfs_readdirplusrpc(vp, uiop, cr); if (error == NFSERR_NOTSUPP) nmp->nm_flag &= ~NFSMNT_RDIRPLUS; } if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) error = nfs_readdirrpc(vp, uiop, cr); 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 { if (((bp->b_blkno * DEV_BSIZE) + bp->b_dirtyend) > np->n_size) bp->b_dirtyend = np->n_size - (bp->b_blkno * DEV_BSIZE); if (bp->b_dirtyend > bp->b_dirtyoff) { 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_CLUSTER)) == B_ASYNC) iomode = NFSV3WRITE_UNSTABLE; else iomode = NFSV3WRITE_FILESYNC; bp->b_flags |= B_WRITEINPROG; error = nfs_writerpc(vp, uiop, cr, &iomode, &must_commit); if (!error && iomode == NFSV3WRITE_UNSTABLE) { bp->b_flags |= B_NEEDCOMMIT; if (bp->b_dirtyoff == 0 && bp->b_dirtyend == bp->b_bufsize) bp->b_flags |= B_CLUSTEROK; } else bp->b_flags &= ~B_NEEDCOMMIT; 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))) { bp->b_flags &= ~(B_INVAL|B_NOCACHE); ++numdirtybuffers; bp->b_flags |= B_DELWRI; reassignbuf(bp, vp); if ((bp->b_flags & B_ASYNC) == 0) 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; } } else { bp->b_resid = 0; biodone(bp); return (0); } } bp->b_resid = uiop->uio_resid; if (must_commit) nfs_clearcommit(vp->v_mount); biodone(bp); return (error); }