/* $NetBSD: nfs_bio.c,v 1.128 2005/02/26 22:39:50 perry 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 __KERNEL_RCSID(0, "$NetBSD: nfs_bio.c,v 1.128 2005/02/26 22:39:50 perry Exp $"); #include "opt_nfs.h" #include "opt_ddb.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern int nfs_numasync; extern int nfs_commitsize; extern struct nfsstats nfsstats; static int nfs_doio_read __P((struct buf *, struct uio *)); static int nfs_doio_write __P((struct buf *, struct uio *)); static int nfs_doio_phys __P((struct buf *, struct uio *)); /* * Vnode op for read using bio * Any similarity to readip() is purely coincidental */ int nfs_bioread(vp, uio, ioflag, cred, cflag) struct vnode *vp; struct uio *uio; int ioflag, cflag; struct ucred *cred; { struct nfsnode *np = VTONFS(vp); struct buf *bp = NULL, *rabp; struct proc *p; struct nfsmount *nmp = VFSTONFS(vp->v_mount); struct nfsdircache *ndp = NULL, *nndp = NULL; caddr_t baddr, ep, edp; int got_buf = 0, error = 0, n = 0, on = 0, en, enn; int enough = 0; struct dirent *dp, *pdp; off_t curoff = 0; #ifdef DIAGNOSTIC if (uio->uio_rw != UIO_READ) panic("nfs_read mode"); #endif if (uio->uio_resid == 0) return (0); if (vp->v_type != VDIR && uio->uio_offset < 0) return (EINVAL); p = uio->uio_procp; #ifndef NFS_V2_ONLY if ((nmp->nm_flag & NFSMNT_NFSV3) && !(nmp->nm_iflag & NFSMNT_GOTFSINFO)) (void)nfs_fsinfo(nmp, vp, cred, p); #endif if (vp->v_type != VDIR && (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) return (EFBIG); /* * 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 && vp->v_type != VLNK) { error = nfs_flushstalebuf(vp, cred, p, NFS_FLUSHSTALEBUF_MYWRITE); if (error) return error; } do { #ifndef NFS_V2_ONLY /* * 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_invaldircache(vp, 0); } 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_invaldircache(vp, 0); error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); if (error) return (error); } } #endif /* * Don't cache symlinks. */ if (np->n_flag & NQNFSNONCACHE || ((vp->v_flag & VROOT) && vp->v_type == VLNK)) { switch (vp->v_type) { case VREG: return (nfs_readrpc(vp, uio)); case VLNK: return (nfs_readlinkrpc(vp, uio, cred)); case VDIR: break; default: printf(" NQNFSNONCACHE: type %x unexpected\n", vp->v_type); }; } baddr = (caddr_t)0; switch (vp->v_type) { case VREG: nfsstats.biocache_reads++; error = 0; if (uio->uio_offset >= np->n_size) { break; } while (uio->uio_resid > 0) { void *win; int flags; vsize_t bytelen = MIN(np->n_size - uio->uio_offset, uio->uio_resid); if (bytelen == 0) break; win = ubc_alloc(&vp->v_uobj, uio->uio_offset, &bytelen, UBC_READ); error = uiomove(win, bytelen, uio); flags = UBC_WANT_UNMAP(vp) ? UBC_UNMAP : 0; ubc_release(win, flags); if (error) { break; } } n = 0; 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_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; case VDIR: diragain: nfsstats.biocache_readdirs++; ndp = nfs_searchdircache(vp, uio->uio_offset, (nmp->nm_flag & NFSMNT_XLATECOOKIE), 0); if (!ndp) { /* * We've been handed a cookie that is not * in the cache. If we're not translating * 32 <-> 64, it may be a value that was * flushed out of the cache because it grew * too big. Let the server judge if it's * valid or not. In the translation case, * we have no way of validating this value, * so punt. */ if (nmp->nm_flag & NFSMNT_XLATECOOKIE) return (EINVAL); ndp = nfs_enterdircache(vp, uio->uio_offset, uio->uio_offset, 0, 0); } if (NFS_EOFVALID(np) && ndp->dc_cookie == np->n_direofoffset) { nfs_putdircache(np, ndp); nfsstats.direofcache_hits++; return (0); } bp = nfs_getcacheblk(vp, NFSDC_BLKNO(ndp), NFS_DIRBLKSIZ, p); if (!bp) return (EINTR); if ((bp->b_flags & B_DONE) == 0) { bp->b_flags |= B_READ; bp->b_dcookie = ndp->dc_blkcookie; error = nfs_doio(bp, p); if (error) { /* * Yuck! The directory has been modified on the * server. Punt and let the userland code * deal with it. */ nfs_putdircache(np, ndp); brelse(bp); if (error == NFSERR_BAD_COOKIE) { nfs_invaldircache(vp, 0); nfs_vinvalbuf(vp, 0, cred, p, 1); error = EINVAL; } return (error); } } /* * Just return if we hit EOF right away with this * block. Always check here, because direofoffset * may have been set by an nfsiod since the last * check. * * also, empty block implies EOF. */ if (bp->b_bcount == bp->b_resid || (NFS_EOFVALID(np) && ndp->dc_blkcookie == np->n_direofoffset)) { KASSERT(bp->b_bcount != bp->b_resid || ndp->dc_blkcookie == bp->b_dcookie); nfs_putdircache(np, ndp); bp->b_flags |= B_NOCACHE; brelse(bp); return 0; } /* * Find the entry we were looking for in the block. */ en = ndp->dc_entry; pdp = dp = (struct dirent *)bp->b_data; edp = bp->b_data + bp->b_bcount - bp->b_resid; enn = 0; while (enn < en && (caddr_t)dp < edp) { pdp = dp; dp = (struct dirent *)((caddr_t)dp + dp->d_reclen); enn++; } /* * If the entry number was bigger than the number of * entries in the block, or the cookie of the previous * entry doesn't match, the directory cache is * stale. Flush it and try again (i.e. go to * the server). */ if ((caddr_t)dp >= edp || (caddr_t)dp + dp->d_reclen > edp || (en > 0 && NFS_GETCOOKIE(pdp) != ndp->dc_cookie)) { #ifdef DEBUG printf("invalid cache: %p %p %p off %lx %lx\n", pdp, dp, edp, (unsigned long)uio->uio_offset, (unsigned long)NFS_GETCOOKIE(pdp)); #endif nfs_putdircache(np, ndp); brelse(bp); nfs_invaldircache(vp, 0); nfs_vinvalbuf(vp, 0, cred, p, 0); goto diragain; } on = (caddr_t)dp - bp->b_data; /* * Cache all entries that may be exported to the * user, as they may be thrown back at us. The * NFSBIO_CACHECOOKIES flag indicates that all * entries are being 'exported', so cache them all. */ if (en == 0 && pdp == dp) { dp = (struct dirent *) ((caddr_t)dp + dp->d_reclen); enn++; } if (uio->uio_resid < (bp->b_bcount - bp->b_resid - on)) { n = uio->uio_resid; enough = 1; } else n = bp->b_bcount - bp->b_resid - on; ep = bp->b_data + on + n; /* * Find last complete entry to copy, caching entries * (if requested) as we go. */ while ((caddr_t)dp < ep && (caddr_t)dp + dp->d_reclen <= ep) { if (cflag & NFSBIO_CACHECOOKIES) { nndp = nfs_enterdircache(vp, NFS_GETCOOKIE(pdp), ndp->dc_blkcookie, enn, bp->b_lblkno); if (nmp->nm_flag & NFSMNT_XLATECOOKIE) { NFS_STASHCOOKIE32(pdp, nndp->dc_cookie32); } nfs_putdircache(np, nndp); } pdp = dp; dp = (struct dirent *)((caddr_t)dp + dp->d_reclen); enn++; } nfs_putdircache(np, ndp); /* * If the last requested entry was not the last in the * buffer (happens if NFS_DIRFRAGSIZ < NFS_DIRBLKSIZ), * cache the cookie of the last requested one, and * set of the offset to it. */ if ((on + n) < bp->b_bcount - bp->b_resid) { curoff = NFS_GETCOOKIE(pdp); nndp = nfs_enterdircache(vp, curoff, ndp->dc_blkcookie, enn, bp->b_lblkno); if (nmp->nm_flag & NFSMNT_XLATECOOKIE) { NFS_STASHCOOKIE32(pdp, nndp->dc_cookie32); curoff = nndp->dc_cookie32; } nfs_putdircache(np, nndp); } else curoff = bp->b_dcookie; /* * Always cache the entry for the next block, * so that readaheads can use it. */ nndp = nfs_enterdircache(vp, bp->b_dcookie, bp->b_dcookie, 0,0); if (nmp->nm_flag & NFSMNT_XLATECOOKIE) { if (curoff == bp->b_dcookie) { NFS_STASHCOOKIE32(pdp, nndp->dc_cookie32); curoff = nndp->dc_cookie32; } } n = ((caddr_t)pdp + pdp->d_reclen) - (bp->b_data + on); /* * 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 && !NFS_EOFVALID(np) && !(np->n_flag & NQNFSNONCACHE)) { rabp = nfs_getcacheblk(vp, NFSDC_BLKNO(nndp), NFS_DIRBLKSIZ, p); if (rabp) { if ((rabp->b_flags & (B_DONE | B_DELWRI)) == 0) { rabp->b_dcookie = nndp->dc_cookie; rabp->b_flags |= (B_READ | B_ASYNC); if (nfs_asyncio(rabp)) { rabp->b_flags |= B_INVAL; brelse(rabp); } } else brelse(rabp); } } nfs_putdircache(np, nndp); got_buf = 1; 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; case VDIR: if (np->n_flag & NQNFSNONCACHE) bp->b_flags |= B_INVAL; uio->uio_offset = curoff; if (enough) 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 /* { struct vnode *a_vp; struct uio *a_uio; int a_ioflag; struct ucred *a_cred; } */ *ap = v; 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; struct vattr vattr; struct nfsmount *nmp = VFSTONFS(vp->v_mount); void *win; voff_t oldoff, origoff; vsize_t bytelen; int flags, error = 0; int ioflag = ap->a_ioflag; int extended = 0, wrotedata = 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); } #ifndef NFS_V2_ONLY if ((nmp->nm_flag & NFSMNT_NFSV3) && !(nmp->nm_iflag & NFSMNT_GOTFSINFO)) (void)nfs_fsinfo(nmp, vp, cred, p); #endif if (ioflag & (IO_APPEND | IO_SYNC)) { if (np->n_flag & NMODIFIED) { NFS_INVALIDATE_ATTRCACHE(np); error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); if (error) return (error); } if (ioflag & IO_APPEND) { NFS_INVALIDATE_ATTRCACHE(np); 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_offset + uio->uio_resid) > nmp->nm_maxfilesize) return (EFBIG); 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); } if ((np->n_flag & NQNFSNONCACHE) && uio->uio_iovcnt == 1) { int iomode = NFSV3WRITE_FILESYNC; boolean_t stalewriteverf = FALSE; lockmgr(&nmp->nm_writeverflock, LK_SHARED, NULL); error = nfs_writerpc(vp, uio, &iomode, FALSE, &stalewriteverf); lockmgr(&nmp->nm_writeverflock, LK_RELEASE, NULL); if (stalewriteverf) nfs_clearcommit(vp->v_mount); return (error); } origoff = uio->uio_offset; do { boolean_t extending; /* if we are extending whole pages */ u_quad_t oldsize; oldoff = uio->uio_offset; bytelen = uio->uio_resid; #ifndef NFS_V2_ONLY /* * 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; } } #endif nfsstats.biocache_writes++; oldsize = np->n_size; np->n_flag |= NMODIFIED; if (np->n_size < uio->uio_offset + bytelen) { np->n_size = uio->uio_offset + bytelen; } extending = ((uio->uio_offset & PAGE_MASK) == 0 && (bytelen & PAGE_MASK) == 0 && uio->uio_offset >= vp->v_size); win = ubc_alloc(&vp->v_uobj, uio->uio_offset, &bytelen, UBC_WRITE | (extending ? UBC_FAULTBUSY : 0)); error = uiomove(win, bytelen, uio); flags = UBC_WANT_UNMAP(vp) ? UBC_UNMAP : 0; ubc_release(win, flags); if (error) { if (extending) { /* * backout size and free pages past eof. */ np->n_size = oldsize; simple_lock(&vp->v_interlock); (void)VOP_PUTPAGES(vp, round_page(vp->v_size), 0, PGO_SYNCIO | PGO_FREE); } break; } wrotedata = 1; /* * update UVM's notion of the size now that we've * copied the data into the vnode's pages. */ if (vp->v_size < uio->uio_offset) { uvm_vnp_setsize(vp, uio->uio_offset); extended = 1; } if ((oldoff & ~(nmp->nm_wsize - 1)) != (uio->uio_offset & ~(nmp->nm_wsize - 1))) { simple_lock(&vp->v_interlock); error = VOP_PUTPAGES(vp, trunc_page(oldoff & ~(nmp->nm_wsize - 1)), round_page((uio->uio_offset + nmp->nm_wsize - 1) & ~(nmp->nm_wsize - 1)), PGO_CLEANIT); } } while (uio->uio_resid > 0); if (wrotedata) VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0)); if ((np->n_flag & NQNFSNONCACHE) || (ioflag & IO_SYNC)) { simple_lock(&vp->v_interlock); error = VOP_PUTPAGES(vp, trunc_page(origoff & ~(nmp->nm_wsize - 1)), round_page((uio->uio_offset + nmp->nm_wsize - 1) & ~(nmp->nm_wsize - 1)), PGO_CLEANIT | PGO_SYNCIO); } return error; } /* * 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; daddr_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 == NULL) { if (nfs_sigintr(nmp, NULL, p)) return (NULL); 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. */ simple_lock(&vp->v_interlock); while (np->n_flag & NFLUSHINPROG) { np->n_flag |= NFLUSHWANT; error = ltsleep(&np->n_flag, PRIBIO + 2, "nfsvinval", slptimeo, &vp->v_interlock); if (error && intrflg && nfs_sigintr(nmp, NULL, p)) { simple_unlock(&vp->v_interlock); return EINTR; } } /* * Now, flush as required. */ np->n_flag |= NFLUSHINPROG; simple_unlock(&vp->v_interlock); error = vinvalbuf(vp, flags, cred, p, slpflag, 0); while (error) { if (intrflg && nfs_sigintr(nmp, NULL, p)) { error = EINTR; break; } error = vinvalbuf(vp, flags, cred, p, 0, slptimeo); } simple_lock(&vp->v_interlock); if (error == 0) np->n_flag &= ~NMODIFIED; np->n_flag &= ~NFLUSHINPROG; if (np->n_flag & NFLUSHWANT) { np->n_flag &= ~NFLUSHWANT; wakeup(&np->n_flag); } simple_unlock(&vp->v_interlock); return error; } /* * nfs_flushstalebuf: flush cache if it's stale. * * => caller shouldn't own any pages or buffers which belong to the vnode. */ int nfs_flushstalebuf(struct vnode *vp, struct ucred *cred, struct proc *p, int flags) { struct nfsnode *np = VTONFS(vp); struct vattr vattr; int error; if (np->n_flag & NMODIFIED) { if ((flags & NFS_FLUSHSTALEBUF_MYWRITE) == 0 || vp->v_type != VREG) { error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); if (error) return error; if (vp->v_type == VDIR) { nfs_invaldircache(vp, 0); } } else { /* * XXX assuming writes are ours. */ } NFS_INVALIDATE_ATTRCACHE(np); error = VOP_GETATTR(vp, &vattr, cred, p); if (error) return error; np->n_mtime = vattr.va_mtime; } else { error = VOP_GETATTR(vp, &vattr, cred, p); if (error) return error; if (timespeccmp(&np->n_mtime, &vattr.va_mtime, !=)) { if (vp->v_type == VDIR) { nfs_invaldircache(vp, 0); } error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1); if (error) return error; np->n_mtime = vattr.va_mtime; } } return error; } /* * 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; struct nfsmount *nmp; int gotiod, slpflag = 0, slptimeo = 0, 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++) { struct nfs_iod *iod = &nfs_asyncdaemon[i]; simple_lock(&iod->nid_slock); if (iod->nid_want) { /* * Found one, so wake it up and tell it which * mount to process. */ iod->nid_want = NULL; iod->nid_mount = nmp; wakeup(&iod->nid_want); simple_lock(&nmp->nm_slock); simple_unlock(&iod->nid_slock); nmp->nm_bufqiods++; gotiod = TRUE; break; } simple_unlock(&iod->nid_slock); } /* * If none are free, we may already have an iod working on this mount * point. If so, it will process our request. */ if (!gotiod) { simple_lock(&nmp->nm_slock); if (nmp->nm_bufqiods > 0) gotiod = TRUE; } LOCK_ASSERT(simple_lock_held(&nmp->nm_slock)); /* * If we have an iod which can process the request, then queue * the buffer. However, even if we have an iod, do not initiate * queue cleaning if curproc is the pageout daemon. if the NFS mount * is via local loopback, we may put curproc (pagedaemon) to sleep * waiting for the writes to complete. But the server (ourself) * may block the write, waiting for its (ie., our) pagedaemon * to produce clean pages to handle the write: deadlock. * XXX: start non-loopback mounts straight away? If "lots free", * let pagedaemon start loopback writes anyway? */ if (gotiod) { /* * Ensure that the queue never grows too large. */ if (curproc == uvm.pagedaemon_proc) { /* Enque for later, to avoid free-page deadlock */ (void) 0; } else while (nmp->nm_bufqlen >= 2*nfs_numasync) { nmp->nm_bufqwant = TRUE; error = ltsleep(&nmp->nm_bufq, slpflag | PRIBIO | PNORELOCK, "nfsaio", slptimeo, &nmp->nm_slock); if (error) { if (nfs_sigintr(nmp, NULL, curproc)) 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) goto again; simple_lock(&nmp->nm_slock); } TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist); nmp->nm_bufqlen++; simple_unlock(&nmp->nm_slock); return (0); } simple_unlock(&nmp->nm_slock); /* * All the iods are busy on other mounts, so return EIO to * force the caller to process the i/o synchronously. */ return (EIO); } /* * nfs_doio for read. */ static int nfs_doio_read(bp, uiop) struct buf *bp; struct uio *uiop; { struct vnode *vp = bp->b_vp; struct nfsnode *np = VTONFS(vp); struct nfsmount *nmp = VFSTONFS(vp->v_mount); int error = 0; uiop->uio_rw = UIO_READ; switch (vp->v_type) { case VREG: nfsstats.read_bios++; error = nfs_readrpc(vp, uiop); if (!error && uiop->uio_resid) { int diff, len; /* * If uio_resid > 0, there is a hole in the file and * no writes after the hole have been pushed to * the server yet or the file has been truncated * on the server. * Just zero fill the rest of the valid area. */ KASSERT(vp->v_size >= uiop->uio_offset + uiop->uio_resid); diff = bp->b_bcount - uiop->uio_resid; len = uiop->uio_resid; memset((char *)bp->b_data + diff, 0, len); } if (uiop->uio_procp && (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) && timespeccmp(&np->n_mtime, &np->n_vattr->va_mtime, !=)))) { uprintf("Process killed due to " "text file modification\n"); psignal(uiop->uio_procp, SIGKILL); #if 0 /* XXX NJWLWP */ uiop->uio_procp->p_holdcnt++; #endif } break; case VLNK: KASSERT(uiop->uio_offset == (off_t)0); nfsstats.readlink_bios++; error = nfs_readlinkrpc(vp, uiop, curproc->p_ucred); break; case VDIR: nfsstats.readdir_bios++; uiop->uio_offset = bp->b_dcookie; #ifndef NFS_V2_ONLY if (nmp->nm_flag & NFSMNT_RDIRPLUS) { error = nfs_readdirplusrpc(vp, uiop, np->n_rcred); if (error == NFSERR_NOTSUPP) nmp->nm_flag &= ~NFSMNT_RDIRPLUS; } #else nmp->nm_flag &= ~NFSMNT_RDIRPLUS; #endif if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0) error = nfs_readdirrpc(vp, uiop, np->n_rcred); if (!error) { bp->b_dcookie = uiop->uio_offset; } break; default: printf("nfs_doio: type %x unexpected\n", vp->v_type); break; } if (error) { bp->b_flags |= B_ERROR; bp->b_error = error; } return error; } /* * nfs_doio for write. */ static int nfs_doio_write(bp, uiop) struct buf *bp; struct uio *uiop; { struct vnode *vp = bp->b_vp; struct nfsnode *np = VTONFS(vp); struct nfsmount *nmp = VFSTONFS(vp->v_mount); int iomode; boolean_t stalewriteverf = FALSE; int i, npages = (bp->b_bcount + PAGE_SIZE - 1) >> PAGE_SHIFT; struct vm_page *pgs[npages]; #ifndef NFS_V2_ONLY boolean_t needcommit = TRUE; /* need only COMMIT RPC */ #else boolean_t needcommit = FALSE; /* need only COMMIT RPC */ #endif boolean_t pageprotected; struct uvm_object *uobj = &vp->v_uobj; int error; off_t off, cnt; if ((bp->b_flags & B_ASYNC) != 0 && NFS_ISV3(vp)) { iomode = NFSV3WRITE_UNSTABLE; } else { iomode = NFSV3WRITE_FILESYNC; } #ifndef NFS_V2_ONLY again: #endif lockmgr(&nmp->nm_writeverflock, LK_SHARED, NULL); for (i = 0; i < npages; i++) { pgs[i] = uvm_pageratop((vaddr_t)bp->b_data + (i << PAGE_SHIFT)); if (pgs[i]->uobject == uobj && pgs[i]->offset == uiop->uio_offset + (i << PAGE_SHIFT)) { KASSERT(pgs[i]->flags & PG_BUSY); /* * this page belongs to our object. */ simple_lock(&uobj->vmobjlock); /* * write out the page stably if it's about to * be released because we can't resend it * on the server crash. * * XXX assuming PG_RELEASE|PG_PAGEOUT won't be * changed until unbusy the page. */ if (pgs[i]->flags & (PG_RELEASED|PG_PAGEOUT)) iomode = NFSV3WRITE_FILESYNC; /* * if we met a page which hasn't been sent yet, * we need do WRITE RPC. */ if ((pgs[i]->flags & PG_NEEDCOMMIT) == 0) needcommit = FALSE; simple_unlock(&uobj->vmobjlock); } else { iomode = NFSV3WRITE_FILESYNC; needcommit = FALSE; } } if (!needcommit && iomode == NFSV3WRITE_UNSTABLE) { simple_lock(&uobj->vmobjlock); for (i = 0; i < npages; i++) { pgs[i]->flags |= PG_NEEDCOMMIT | PG_RDONLY; pmap_page_protect(pgs[i], VM_PROT_READ); } simple_unlock(&uobj->vmobjlock); pageprotected = TRUE; /* pages can't be modified during i/o. */ } else pageprotected = FALSE; /* * Send the data to the server if necessary, * otherwise just send a commit rpc. */ #ifndef NFS_V2_ONLY if (needcommit) { /* * If the buffer is in the range that we already committed, * there's nothing to do. * * If it's in the range that we need to commit, push the * whole range at once, otherwise only push the buffer. * In both these cases, acquire the commit lock to avoid * other processes modifying the range. */ off = uiop->uio_offset; cnt = bp->b_bcount; lockmgr(&np->n_commitlock, LK_EXCLUSIVE, NULL); if (!nfs_in_committed_range(vp, off, bp->b_bcount)) { boolean_t pushedrange; if (nfs_in_tobecommitted_range(vp, off, bp->b_bcount)) { pushedrange = TRUE; off = np->n_pushlo; cnt = np->n_pushhi - np->n_pushlo; } else { pushedrange = FALSE; } error = nfs_commit(vp, off, cnt, curproc); if (error == 0) { if (pushedrange) { nfs_merge_commit_ranges(vp); } else { nfs_add_committed_range(vp, off, cnt); } } } else { error = 0; } lockmgr(&np->n_commitlock, LK_RELEASE, NULL); lockmgr(&nmp->nm_writeverflock, LK_RELEASE, NULL); if (!error) { /* * pages are now on stable storage. */ uiop->uio_resid = 0; simple_lock(&uobj->vmobjlock); for (i = 0; i < npages; i++) { pgs[i]->flags &= ~(PG_NEEDCOMMIT | PG_RDONLY); } simple_unlock(&uobj->vmobjlock); return 0; } else if (error == NFSERR_STALEWRITEVERF) { nfs_clearcommit(vp->v_mount); goto again; } if (error) { bp->b_flags |= B_ERROR; bp->b_error = np->n_error = error; np->n_flag |= NWRITEERR; } return error; } #endif off = uiop->uio_offset; cnt = bp->b_bcount; uiop->uio_rw = UIO_WRITE; nfsstats.write_bios++; error = nfs_writerpc(vp, uiop, &iomode, pageprotected, &stalewriteverf); #ifndef NFS_V2_ONLY if (!error && iomode == NFSV3WRITE_UNSTABLE) { /* * we need to commit pages later. */ lockmgr(&np->n_commitlock, LK_EXCLUSIVE, NULL); nfs_add_tobecommitted_range(vp, off, cnt); /* * if there can be too many uncommitted pages, commit them now. */ if (np->n_pushhi - np->n_pushlo > nfs_commitsize) { off = np->n_pushlo; cnt = nfs_commitsize >> 1; error = nfs_commit(vp, off, cnt, curproc); if (!error) { nfs_add_committed_range(vp, off, cnt); nfs_del_tobecommitted_range(vp, off, cnt); } if (error == NFSERR_STALEWRITEVERF) { stalewriteverf = TRUE; error = 0; /* it isn't a real error */ } } else { /* * re-dirty pages so that they will be passed * to us later again. */ simple_lock(&uobj->vmobjlock); for (i = 0; i < npages; i++) { pgs[i]->flags &= ~PG_CLEAN; } simple_unlock(&uobj->vmobjlock); } lockmgr(&np->n_commitlock, LK_RELEASE, NULL); } else #endif if (!error) { /* * pages are now on stable storage. */ lockmgr(&np->n_commitlock, LK_EXCLUSIVE, NULL); nfs_del_committed_range(vp, off, cnt); lockmgr(&np->n_commitlock, LK_RELEASE, NULL); simple_lock(&uobj->vmobjlock); for (i = 0; i < npages; i++) { pgs[i]->flags &= ~(PG_NEEDCOMMIT | PG_RDONLY); } simple_unlock(&uobj->vmobjlock); } else { /* * we got an error. */ bp->b_flags |= B_ERROR; bp->b_error = np->n_error = error; np->n_flag |= NWRITEERR; } lockmgr(&nmp->nm_writeverflock, LK_RELEASE, NULL); if (stalewriteverf) { nfs_clearcommit(vp->v_mount); } return error; } /* * nfs_doio for B_PHYS. */ static int nfs_doio_phys(bp, uiop) struct buf *bp; struct uio *uiop; { struct vnode *vp = bp->b_vp; int error; 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 { int iomode = NFSV3WRITE_DATASYNC; boolean_t stalewriteverf; struct nfsmount *nmp = VFSTONFS(vp->v_mount); uiop->uio_rw = UIO_WRITE; nfsstats.write_physios++; lockmgr(&nmp->nm_writeverflock, LK_SHARED, NULL); error = nfs_writerpc(vp, uiop, &iomode, FALSE, &stalewriteverf); lockmgr(&nmp->nm_writeverflock, LK_RELEASE, NULL); if (stalewriteverf) { nfs_clearcommit(bp->b_vp->v_mount); } } if (error) { bp->b_flags |= B_ERROR; bp->b_error = error; } return error; } /* * 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; { int error; struct uio uio; struct uio *uiop = &uio; struct iovec io; UVMHIST_FUNC("nfs_doio"); UVMHIST_CALLED(ubchist); uiop->uio_iov = &io; uiop->uio_iovcnt = 1; uiop->uio_segflg = UIO_SYSSPACE; uiop->uio_procp = NULL; uiop->uio_offset = (((off_t)bp->b_blkno) << DEV_BSHIFT); io.iov_base = bp->b_data; io.iov_len = uiop->uio_resid = bp->b_bcount; /* * Historically, paging was done with physio, but no more... */ if (bp->b_flags & B_PHYS) { /* * ...though reading /dev/drum still gets us here. */ error = nfs_doio_phys(bp, uiop); } else if (bp->b_flags & B_READ) { error = nfs_doio_read(bp, uiop); } else { error = nfs_doio_write(bp, uiop); } bp->b_resid = uiop->uio_resid; biodone(bp); return (error); } /* * Vnode op for VM getpages. */ int nfs_getpages(v) void *v; { struct vop_getpages_args /* { struct vnode *a_vp; voff_t a_offset; struct vm_page **a_m; int *a_count; int a_centeridx; vm_prot_t a_access_type; int a_advice; int a_flags; } */ *ap = v; struct vnode *vp = ap->a_vp; struct uvm_object *uobj = &vp->v_uobj; struct nfsnode *np = VTONFS(vp); const int npages = *ap->a_count; struct vm_page *pg, **pgs, *opgs[npages]; off_t origoffset, len; int i, error; boolean_t v3 = NFS_ISV3(vp); boolean_t write = (ap->a_access_type & VM_PROT_WRITE) != 0; boolean_t locked = (ap->a_flags & PGO_LOCKED) != 0; /* * call the genfs code to get the pages. `pgs' may be NULL * when doing read-ahead. */ pgs = ap->a_m; if (write && locked && v3) { KASSERT(pgs != NULL); #ifdef DEBUG /* * If PGO_LOCKED is set, real pages shouldn't exists * in the array. */ for (i = 0; i < npages; i++) KDASSERT(pgs[i] == NULL || pgs[i] == PGO_DONTCARE); #endif memcpy(opgs, pgs, npages * sizeof(struct vm_pages *)); } error = genfs_getpages(v); if (error) { return (error); } /* * for read faults where the nfs node is not yet marked NMODIFIED, * set PG_RDONLY on the pages so that we come back here if someone * tries to modify later via the mapping that will be entered for * this fault. */ if (!write && (np->n_flag & NMODIFIED) == 0 && pgs != NULL) { if (!locked) { simple_lock(&uobj->vmobjlock); } for (i = 0; i < npages; i++) { pg = pgs[i]; if (pg == NULL || pg == PGO_DONTCARE) { continue; } pg->flags |= PG_RDONLY; } if (!locked) { simple_unlock(&uobj->vmobjlock); } } if (!write) { return (0); } /* * this is a write fault, update the commit info. */ origoffset = ap->a_offset; len = npages << PAGE_SHIFT; if (v3) { error = lockmgr(&np->n_commitlock, LK_EXCLUSIVE | (locked ? LK_NOWAIT : 0), NULL); if (error) { KASSERT(locked != 0); /* * Since PGO_LOCKED is set, we need to unbusy * all pages fetched by genfs_getpages() above, * tell the caller that there are no pages * available and put back original pgs array. */ uvm_lock_pageq(); uvm_page_unbusy(pgs, npages); uvm_unlock_pageq(); *ap->a_count = 0; memcpy(pgs, opgs, npages * sizeof(struct vm_pages *)); return (error); } nfs_del_committed_range(vp, origoffset, len); nfs_del_tobecommitted_range(vp, origoffset, len); } np->n_flag |= NMODIFIED; if (!locked) { simple_lock(&uobj->vmobjlock); } for (i = 0; i < npages; i++) { pg = pgs[i]; if (pg == NULL || pg == PGO_DONTCARE) { continue; } pg->flags &= ~(PG_NEEDCOMMIT | PG_RDONLY); } if (!locked) { simple_unlock(&uobj->vmobjlock); } if (v3) { lockmgr(&np->n_commitlock, LK_RELEASE, NULL); } return (0); }