/* * 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 */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Just call nfs_writebp() with the force argument set to 1. * * NOTE: B_DONE may or may not be set in a_bp on call. */ static int nfs_bwrite(struct buf *bp) { return (nfs_writebp(bp, 1, curthread)); } struct buf_ops buf_ops_nfs = { "buf_ops_nfs", nfs_bwrite }; static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td); /* * Vnode op for VM getpages. */ int nfs_getpages(struct vop_getpages_args *ap) { int i, error, nextoff, size, toff, count, npages; struct uio uio; struct iovec iov; vm_offset_t kva; struct buf *bp; struct vnode *vp; struct thread *td; struct ucred *cred; struct nfsmount *nmp; vm_object_t object; vm_page_t *pages; GIANT_REQUIRED; vp = ap->a_vp; td = curthread; /* XXX */ cred = curthread->td_ucred; /* XXX */ nmp = VFSTONFS(vp->v_mount); pages = ap->a_m; count = ap->a_count; if ((object = vp->v_object) == NULL) { printf("nfs_getpages: called with non-merged cache vnode??\n"); return VM_PAGER_ERROR; } if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { (void)nfs_fsinfo(nmp, vp, cred, td); } npages = btoc(count); /* * If the requested page is partially valid, just return it and * allow the pager to zero-out the blanks. Partially valid pages * can only occur at the file EOF. */ { vm_page_t m = pages[ap->a_reqpage]; VM_OBJECT_LOCK(object); vm_page_lock_queues(); if (m->valid != 0) { /* handled by vm_fault now */ /* vm_page_zero_invalid(m, TRUE); */ for (i = 0; i < npages; ++i) { if (i != ap->a_reqpage) vm_page_free(pages[i]); } vm_page_unlock_queues(); VM_OBJECT_UNLOCK(object); return(0); } vm_page_unlock_queues(); VM_OBJECT_UNLOCK(object); } /* * We use only the kva address for the buffer, but this is extremely * convienient and fast. */ bp = getpbuf(&nfs_pbuf_freecnt); kva = (vm_offset_t) bp->b_data; pmap_qenter(kva, pages, npages); cnt.v_vnodein++; cnt.v_vnodepgsin += npages; iov.iov_base = (caddr_t) kva; iov.iov_len = count; uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = IDX_TO_OFF(pages[0]->pindex); uio.uio_resid = count; uio.uio_segflg = UIO_SYSSPACE; uio.uio_rw = UIO_READ; uio.uio_td = td; error = nfs_readrpc(vp, &uio, cred); pmap_qremove(kva, npages); relpbuf(bp, &nfs_pbuf_freecnt); if (error && (uio.uio_resid == count)) { printf("nfs_getpages: error %d\n", error); VM_OBJECT_LOCK(object); vm_page_lock_queues(); for (i = 0; i < npages; ++i) { if (i != ap->a_reqpage) vm_page_free(pages[i]); } vm_page_unlock_queues(); VM_OBJECT_UNLOCK(object); return VM_PAGER_ERROR; } /* * Calculate the number of bytes read and validate only that number * of bytes. Note that due to pending writes, size may be 0. This * does not mean that the remaining data is invalid! */ size = count - uio.uio_resid; VM_OBJECT_LOCK(object); vm_page_lock_queues(); for (i = 0, toff = 0; i < npages; i++, toff = nextoff) { vm_page_t m; nextoff = toff + PAGE_SIZE; m = pages[i]; m->flags &= ~PG_ZERO; if (nextoff <= size) { /* * Read operation filled an entire page */ m->valid = VM_PAGE_BITS_ALL; vm_page_undirty(m); } else if (size > toff) { /* * Read operation filled a partial page. */ m->valid = 0; vm_page_set_validclean(m, 0, size - toff); /* handled by vm_fault now */ /* vm_page_zero_invalid(m, TRUE); */ } else { /* * Read operation was short. If no error occured * we may have hit a zero-fill section. We simply * leave valid set to 0. */ ; } if (i != ap->a_reqpage) { /* * Whether or not to leave the page activated is up in * the air, but we should put the page on a page queue * somewhere (it already is in the object). Result: * It appears that emperical results show that * deactivating pages is best. */ /* * Just in case someone was asking for this page we * now tell them that it is ok to use. */ if (!error) { if (m->flags & PG_WANTED) vm_page_activate(m); else vm_page_deactivate(m); vm_page_wakeup(m); } else { vm_page_free(m); } } } vm_page_unlock_queues(); VM_OBJECT_UNLOCK(object); return 0; } /* * Vnode op for VM putpages. */ int nfs_putpages(struct vop_putpages_args *ap) { struct uio uio; struct iovec iov; vm_offset_t kva; struct buf *bp; int iomode, must_commit, i, error, npages, count; off_t offset; int *rtvals; struct vnode *vp; struct thread *td; struct ucred *cred; struct nfsmount *nmp; struct nfsnode *np; vm_page_t *pages; GIANT_REQUIRED; vp = ap->a_vp; np = VTONFS(vp); td = curthread; /* XXX */ cred = curthread->td_ucred; /* XXX */ nmp = VFSTONFS(vp->v_mount); pages = ap->a_m; count = ap->a_count; rtvals = ap->a_rtvals; npages = btoc(count); offset = IDX_TO_OFF(pages[0]->pindex); if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) { (void)nfs_fsinfo(nmp, vp, cred, td); } for (i = 0; i < npages; i++) rtvals[i] = VM_PAGER_AGAIN; /* * When putting pages, do not extend file past EOF. */ if (offset + count > np->n_size) { count = np->n_size - offset; if (count < 0) count = 0; } /* * We use only the kva address for the buffer, but this is extremely * convienient and fast. */ bp = getpbuf(&nfs_pbuf_freecnt); kva = (vm_offset_t) bp->b_data; pmap_qenter(kva, pages, npages); cnt.v_vnodeout++; cnt.v_vnodepgsout += count; iov.iov_base = (caddr_t) kva; iov.iov_len = count; uio.uio_iov = &iov; uio.uio_iovcnt = 1; uio.uio_offset = offset; uio.uio_resid = count; uio.uio_segflg = UIO_SYSSPACE; uio.uio_rw = UIO_WRITE; uio.uio_td = td; if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0) iomode = NFSV3WRITE_UNSTABLE; else iomode = NFSV3WRITE_FILESYNC; error = nfs_writerpc(vp, &uio, cred, &iomode, &must_commit); pmap_qremove(kva, npages); relpbuf(bp, &nfs_pbuf_freecnt); if (!error) { int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE; for (i = 0; i < nwritten; i++) { rtvals[i] = VM_PAGER_OK; vm_page_undirty(pages[i]); } if (must_commit) { nfs_clearcommit(vp->v_mount); } } return rtvals[0]; } /* * Vnode op for read using bio */ int nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred) { struct nfsnode *np = VTONFS(vp); int biosize, i; struct buf *bp = 0, *rabp; struct vattr vattr; struct thread *td; struct nfsmount *nmp = VFSTONFS(vp->v_mount); daddr_t lbn, rabn; int bcount; int seqcount; int nra, error = 0, n = 0, on = 0; #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) /* XXX VDIR cookies can be negative */ return (EINVAL); td = uio->uio_td; if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 && (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) (void)nfs_fsinfo(nmp, vp, cred, td); if (vp->v_type != VDIR && (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize) return (EFBIG); biosize = vp->v_mount->mnt_stat.f_iosize; seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE); /* * 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) { 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, td, 1); if (error) return (error); } np->n_attrstamp = 0; error = VOP_GETATTR(vp, &vattr, cred, td); if (error) return (error); np->n_mtime = vattr.va_mtime.tv_sec; } else { error = VOP_GETATTR(vp, &vattr, cred, td); 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, td, 1); if (error) return (error); np->n_mtime = vattr.va_mtime.tv_sec; } } do { switch (vp->v_type) { case VREG: nfsstats.biocache_reads++; lbn = uio->uio_offset / biosize; on = uio->uio_offset & (biosize - 1); /* * Start the read ahead(s), as required. */ if (nmp->nm_readahead > 0) { for (nra = 0; nra < nmp->nm_readahead && nra < seqcount && (off_t)(lbn + 1 + nra) * biosize < np->n_size; nra++) { rabn = lbn + 1 + nra; if (incore(vp, rabn) == NULL) { rabp = nfs_getcacheblk(vp, rabn, biosize, td); if (!rabp) return (EINTR); if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { rabp->b_flags |= B_ASYNC; rabp->b_iocmd = BIO_READ; vfs_busy_pages(rabp, 0); if (nfs_asyncio(rabp, cred, td)) { rabp->b_flags |= B_INVAL; rabp->b_ioflags |= BIO_ERROR; vfs_unbusy_pages(rabp); brelse(rabp); break; } } else { brelse(rabp); } } } } /* * Obtain the buffer cache block. Figure out the buffer size * when we are at EOF. If we are modifying the size of the * buffer based on an EOF condition we need to hold * nfs_rslock() through obtaining the buffer to prevent * a potential writer-appender from messing with n_size. * Otherwise we may accidently truncate the buffer and * lose dirty data. * * Note that bcount is *not* DEV_BSIZE aligned. */ again: bcount = biosize; if ((off_t)lbn * biosize >= np->n_size) { bcount = 0; } else if ((off_t)(lbn + 1) * biosize > np->n_size) { bcount = np->n_size - (off_t)lbn * biosize; } if (bcount != biosize) { switch(nfs_rslock(np, td)) { case ENOLCK: goto again; /* not reached */ case EINTR: case ERESTART: return(EINTR); /* not reached */ default: break; } } bp = nfs_getcacheblk(vp, lbn, bcount, td); if (bcount != biosize) nfs_rsunlock(np, td); if (!bp) return (EINTR); /* * If B_CACHE is not set, we must issue the read. If this * fails, we return an error. */ if ((bp->b_flags & B_CACHE) == 0) { bp->b_iocmd = BIO_READ; vfs_busy_pages(bp, 0); error = nfs_doio(bp, cred, td); if (error) { brelse(bp); return (error); } } /* * on is the offset into the current bp. Figure out how many * bytes we can copy out of the bp. Note that bcount is * NOT DEV_BSIZE aligned. * * Then figure out how many bytes we can copy into the uio. */ n = 0; if (on < bcount) n = min((unsigned)(bcount - on), uio->uio_resid); break; case VLNK: nfsstats.biocache_readlinks++; bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td); if (!bp) return (EINTR); if ((bp->b_flags & B_CACHE) == 0) { bp->b_iocmd = BIO_READ; vfs_busy_pages(bp, 0); error = nfs_doio(bp, cred, td); if (error) { bp->b_ioflags |= BIO_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 = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ; on = uio->uio_offset & (NFS_DIRBLKSIZ - 1); bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td); if (!bp) return (EINTR); if ((bp->b_flags & B_CACHE) == 0) { bp->b_iocmd = BIO_READ; vfs_busy_pages(bp, 0); error = nfs_doio(bp, cred, td); if (error) { brelse(bp); } while (error == NFSERR_BAD_COOKIE) { printf("got bad cookie vp %p bp %p\n", vp, bp); nfs_invaldir(vp); error = nfs_vinvalbuf(vp, 0, cred, td, 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. * * Leave the last bp intact unless there is an error. * Loop back up to the while if the error is another * NFSERR_BAD_COOKIE (double yuch!). */ 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, td); if (!bp) return (EINTR); if ((bp->b_flags & B_CACHE) == 0) { bp->b_iocmd = BIO_READ; vfs_busy_pages(bp, 0); error = nfs_doio(bp, cred, td); /* * no error + B_INVAL == directory EOF, * use the block. */ if (error == 0 && (bp->b_flags & B_INVAL)) break; } /* * An error will throw away the block and the * for loop will break out. If no error and this * is not the block we want, we throw away the * block and go for the next one via the for loop. */ if (error || i < lbn) brelse(bp); } } /* * The above while is repeated if we hit another cookie * error. If we hit an error and it wasn't a cookie error, * we give up. */ 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 (nmp->nm_readahead > 0 && (bp->b_flags & B_INVAL) == 0 && (np->n_direofoffset == 0 || (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) && incore(vp, lbn + 1) == NULL) { rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td); if (rabp) { if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) { rabp->b_flags |= B_ASYNC; rabp->b_iocmd = BIO_READ; vfs_busy_pages(rabp, 0); if (nfs_asyncio(rabp, cred, td)) { rabp->b_flags |= B_INVAL; rabp->b_ioflags |= BIO_ERROR; vfs_unbusy_pages(rabp); brelse(rabp); } } else { brelse(rabp); } } } /* * Unlike VREG files, whos buffer size ( bp->b_bcount ) is * chopped for the EOF condition, we cannot tell how large * NFS directories are going to be until we hit EOF. So * an NFS directory buffer is *not* chopped to its EOF. Now, * it just so happens that b_resid will effectively chop it * to EOF. *BUT* this information is lost if the buffer goes * away and is reconstituted into a B_CACHE state ( due to * being VMIO ) later. So we keep track of the directory eof * in np->n_direofoffset and chop it off as an extra step * right here. */ n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on); if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset) n = np->n_direofoffset - uio->uio_offset; 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: 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(struct vop_write_args *ap) { int biosize; struct uio *uio = ap->a_uio; struct thread *td = uio->uio_td; 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); daddr_t lbn; int bcount; int n, on, error = 0; int haverslock = 0; struct proc *p = td?td->td_proc:NULL; GIANT_REQUIRED; #ifdef DIAGNOSTIC if (uio->uio_rw != UIO_WRITE) panic("nfs_write mode"); if (uio->uio_segflg == UIO_USERSPACE && uio->uio_td != curthread) 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) != 0 && (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) (void)nfs_fsinfo(nmp, vp, cred, td); /* * Synchronously flush pending buffers if we are in synchronous * mode or if we are appending. */ if (ioflag & (IO_APPEND | IO_SYNC)) { if (np->n_flag & NMODIFIED) { np->n_attrstamp = 0; error = nfs_vinvalbuf(vp, V_SAVE, cred, td, 1); if (error) return (error); } } /* * If IO_APPEND then load uio_offset. We restart here if we cannot * get the append lock. */ restart: if (ioflag & IO_APPEND) { np->n_attrstamp = 0; error = VOP_GETATTR(vp, &vattr, cred, td); 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); /* * We need to obtain the rslock if we intend to modify np->n_size * in order to guarentee the append point with multiple contending * writers, to guarentee that no other appenders modify n_size * while we are trying to obtain a truncated buffer (i.e. to avoid * accidently truncating data written by another appender due to * the race), and to ensure that the buffer is populated prior to * our extending of the file. We hold rslock through the entire * operation. * * Note that we do not synchronize the case where someone truncates * the file while we are appending to it because attempting to lock * this case may deadlock other parts of the system unexpectedly. */ if ((ioflag & IO_APPEND) || uio->uio_offset + uio->uio_resid > np->n_size) { switch(nfs_rslock(np, td)) { case ENOLCK: goto restart; /* not reached */ case EINTR: case ERESTART: return(EINTR); /* not reached */ default: break; } haverslock = 1; } /* * 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) { PROC_LOCK(p); psignal(p, SIGXFSZ); PROC_UNLOCK(p); if (haverslock) nfs_rsunlock(np, td); return (EFBIG); } biosize = vp->v_mount->mnt_stat.f_iosize; do { nfsstats.biocache_writes++; lbn = uio->uio_offset / biosize; on = uio->uio_offset & (biosize-1); n = min((unsigned)(biosize - on), uio->uio_resid); again: /* * Handle direct append and file extension cases, calculate * unaligned buffer size. */ if (uio->uio_offset == np->n_size && n) { /* * Get the buffer (in its pre-append state to maintain * B_CACHE if it was previously set). Resize the * nfsnode after we have locked the buffer to prevent * readers from reading garbage. */ bcount = on; bp = nfs_getcacheblk(vp, lbn, bcount, td); if (bp != NULL) { long save; np->n_size = uio->uio_offset + n; np->n_flag |= NMODIFIED; vnode_pager_setsize(vp, np->n_size); save = bp->b_flags & B_CACHE; bcount += n; allocbuf(bp, bcount); bp->b_flags |= save; bp->b_magic = B_MAGIC_NFS; bp->b_op = &buf_ops_nfs; } } else { /* * Obtain the locked cache block first, and then * adjust the file's size as appropriate. */ bcount = on + n; if ((off_t)lbn * biosize + bcount < np->n_size) { if ((off_t)(lbn + 1) * biosize < np->n_size) bcount = biosize; else bcount = np->n_size - (off_t)lbn * biosize; } bp = nfs_getcacheblk(vp, lbn, bcount, td); if (uio->uio_offset + n > np->n_size) { np->n_size = uio->uio_offset + n; np->n_flag |= NMODIFIED; vnode_pager_setsize(vp, np->n_size); } } if (!bp) { error = EINTR; break; } /* * Issue a READ if B_CACHE is not set. In special-append * mode, B_CACHE is based on the buffer prior to the write * op and is typically set, avoiding the read. If a read * is required in special append mode, the server will * probably send us a short-read since we extended the file * on our end, resulting in b_resid == 0 and, thusly, * B_CACHE getting set. * * We can also avoid issuing the read if the write covers * the entire buffer. We have to make sure the buffer state * is reasonable in this case since we will not be initiating * I/O. See the comments in kern/vfs_bio.c's getblk() for * more information. * * B_CACHE may also be set due to the buffer being cached * normally. */ if (on == 0 && n == bcount) { bp->b_flags |= B_CACHE; bp->b_flags &= ~B_INVAL; bp->b_ioflags &= ~BIO_ERROR; } if ((bp->b_flags & B_CACHE) == 0) { bp->b_iocmd = BIO_READ; vfs_busy_pages(bp, 0); error = nfs_doio(bp, cred, td); if (error) { brelse(bp); break; } } if (!bp) { error = EINTR; break; } if (bp->b_wcred == NOCRED) bp->b_wcred = crhold(cred); np->n_flag |= NMODIFIED; /* * If dirtyend exceeds file size, chop it down. This should * not normally occur but there is an append race where it * might occur XXX, so we log it. * * If the chopping creates a reverse-indexed or degenerate * situation with dirtyoff/end, we 0 both of them. */ if (bp->b_dirtyend > bcount) { printf("NFS append race @%lx:%d\n", (long)bp->b_blkno * DEV_BSIZE, bp->b_dirtyend - bcount); bp->b_dirtyend = bcount; } if (bp->b_dirtyoff >= bp->b_dirtyend) bp->b_dirtyoff = bp->b_dirtyend = 0; /* * 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. * * While it is possible to merge discontiguous writes due to * our having a B_CACHE buffer ( and thus valid read data * for the hole), we don't because it could lead to * significant cache coherency problems with multiple clients, * especially if locking is implemented later on. * * as an optimization we could theoretically maintain * a linked list of discontinuous areas, but we would still * have to commit them separately so there isn't much * advantage to it except perhaps a bit of asynchronization. */ if (bp->b_dirtyend > 0 && (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) { if (BUF_WRITE(bp) == EINTR) { error = EINTR; break; } goto again; } error = uiomove((char *)bp->b_data + on, n, uio); /* * Since this block is being modified, it must be written * again and not just committed. Since write clustering does * not work for the stage 1 data write, only the stage 2 * commit rpc, we have to clear B_CLUSTEROK as well. */ bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); if (error) { bp->b_ioflags |= BIO_ERROR; brelse(bp); break; } /* * Only update dirtyoff/dirtyend if not a degenerate * condition. */ if (n) { 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; } vfs_bio_set_validclean(bp, on, n); } /* * If IO_SYNC do bwrite(). * * IO_INVAL appears to be unused. The idea appears to be * to turn off caching in this case. Very odd. XXX */ if ((ioflag & IO_SYNC)) { if (ioflag & IO_INVAL) bp->b_flags |= B_NOCACHE; error = BUF_WRITE(bp); if (error) break; } else if ((n + on) == biosize) { bp->b_flags |= B_ASYNC; (void)nfs_writebp(bp, 0, 0); } else { bdwrite(bp); } } while (uio->uio_resid > 0 && n > 0); if (haverslock) nfs_rsunlock(np, td); 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. * * The caller must carefully deal with the possible B_INVAL state of * the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it * indirectly), so synchronous reads can be issued without worrying about * the B_INVAL state. We have to be a little more careful when dealing * with writes (see comments in nfs_write()) when extending a file past * its EOF. */ static struct buf * nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td) { 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, 0); while (bp == NULL) { if (nfs_sigintr(nmp, NULL, td)) return (NULL); bp = getblk(vp, bn, size, 0, 2 * hz, 0); } } else { bp = getblk(vp, bn, size, 0, 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(struct vnode *vp, int flags, struct ucred *cred, struct thread *td, int intrflg) { struct nfsnode *np = VTONFS(vp); struct nfsmount *nmp = VFSTONFS(vp->v_mount); int error = 0, slpflag, slptimeo; ASSERT_VOP_LOCKED(vp, "nfs_vinvalbuf"); /* * XXX This check stops us from needlessly doing a vinvalbuf when * being called through vclean(). It is not clear that this is * unsafe. */ if (vp->v_iflag & VI_XLOCK) 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(&np->n_flag, PRIBIO + 2, "nfsvinval", slptimeo); if (error && intrflg && nfs_sigintr(nmp, NULL, td)) return (EINTR); } /* * Now, flush as required. */ np->n_flag |= NFLUSHINPROG; error = vinvalbuf(vp, flags, cred, td, slpflag, 0); while (error) { if (intrflg && nfs_sigintr(nmp, NULL, td)) { np->n_flag &= ~NFLUSHINPROG; if (np->n_flag & NFLUSHWANT) { np->n_flag &= ~NFLUSHWANT; wakeup(&np->n_flag); } return (EINTR); } error = vinvalbuf(vp, flags, cred, td, 0, slptimeo); } np->n_flag &= ~(NMODIFIED | NFLUSHINPROG); if (np->n_flag & NFLUSHWANT) { np->n_flag &= ~NFLUSHWANT; wakeup(&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. * * Note: nfs_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp * is eventually dequeued by the async daemon, nfs_doio() *will*. */ int nfs_asyncio(struct buf *bp, struct ucred *cred, struct thread *td) { struct nfsmount *nmp; int iod; int gotiod; int slpflag = 0; int slptimeo = 0; int error; nmp = VFSTONFS(bp->b_vp->v_mount); /* * Commits are usually short and sweet so lets save some cpu and * leave the async daemons for more important rpc's (such as reads * and writes). */ if (bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) && (nmp->nm_bufqiods > nfs_numasync / 2)) { return(EIO); } again: if (nmp->nm_flag & NFSMNT_INT) slpflag = PCATCH; gotiod = FALSE; /* * Find a free iod to process this request. */ for (iod = 0; iod < nfs_numasync; iod++) if (nfs_iodwant[iod]) { gotiod = TRUE; break; } /* * Try to create one if none are free. */ if (!gotiod) { iod = nfs_nfsiodnew(); if (iod != -1) gotiod = TRUE; } if (gotiod) { /* * 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", iod, nmp)); nfs_iodwant[iod] = NULL; nfs_iodmount[iod] = nmp; nmp->nm_bufqiods++; wakeup(&nfs_iodwant[iod]); } /* * 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. We still want * to asynchronize so we block rather then return EIO. */ 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, td)) 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_iocmd == BIO_READ) { if (bp->b_rcred == NOCRED && cred != NOCRED) bp->b_rcred = crhold(cred); } else { bp->b_flags |= B_WRITEINPROG; if (bp->b_wcred == NOCRED && cred != NOCRED) bp->b_wcred = crhold(cred); } BUF_KERNPROC(bp); 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(struct buf *bp, struct ucred *cr, struct thread *td) { struct uio *uiop; struct vnode *vp; struct nfsnode *np; struct nfsmount *nmp; int error = 0, iomode, must_commit = 0; struct uio uio; struct iovec io; struct proc *p = td ? td->td_proc : NULL; 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_td = td; /* * clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We * do this here so we do not have to do it in all the code that * calls us. */ bp->b_flags &= ~B_INVAL; bp->b_ioflags &= ~BIO_ERROR; KASSERT(!(bp->b_flags & B_DONE), ("nfs_doio: bp %p already marked done", bp)); if (bp->b_iocmd == BIO_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) { if (uiop->uio_resid) { /* * If we had a short read with no error, we must have * hit a file hole. We should zero-fill the remainder. * This can also occur if the server hits the file EOF. * * Holes used to be able to occur due to pending * writes, but that is not possible any longer. */ int nread = bp->b_bcount - uiop->uio_resid; int left = uiop->uio_resid; if (left > 0) bzero((char *)bp->b_data + nread, left); uiop->uio_resid = 0; } } /* ASSERT_VOP_LOCKED(vp, "nfs_doio"); */ if (p && (vp->v_vflag & VV_TEXT) && (np->n_mtime != np->n_vattr.va_mtime.tv_sec)) { uprintf("Process killed due to text file modification\n"); PROC_LOCK(p); psignal(p, SIGKILL); _PHOLD(p); PROC_UNLOCK(p); } 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); /* * end-of-directory sets B_INVAL but does not generate an * error. */ if (error == 0 && uiop->uio_resid == bp->b_bcount) bp->b_flags |= B_INVAL; break; default: printf("nfs_doio: type %x unexpected\n", vp->v_type); break; }; if (error) { bp->b_ioflags |= BIO_ERROR; bp->b_error = error; } } else { /* * If we only need to commit, try to commit */ if (bp->b_flags & B_NEEDCOMMIT) { int retv; off_t off; off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff; bp->b_flags |= B_WRITEINPROG; retv = nfs_commit( bp->b_vp, off, bp->b_dirtyend-bp->b_dirtyoff, bp->b_wcred, td); bp->b_flags &= ~B_WRITEINPROG; if (retv == 0) { bp->b_dirtyoff = bp->b_dirtyend = 0; bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); bp->b_resid = 0; bufdone(bp); return (0); } if (retv == NFSERR_STALEWRITEVERF) { nfs_clearcommit(bp->b_vp->v_mount); } } /* * Setup for actual write */ if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size) bp->b_dirtyend = np->n_size - (off_t)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); /* * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try * to cluster the buffers needing commit. This will allow * the system to submit a single commit rpc for the whole * cluster. We can do this even if the buffer is not 100% * dirty (relative to the NFS blocksize), so we optimize the * append-to-file-case. * * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be * cleared because write clustering only works for commit * rpc's, not for the data portion of the write). */ if (!error && iomode == NFSV3WRITE_UNSTABLE) { bp->b_flags |= B_NEEDCOMMIT; if (bp->b_dirtyoff == 0 && bp->b_dirtyend == bp->b_bcount) bp->b_flags |= B_CLUSTEROK; } else { bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK); } 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 BIO_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 the buffer is marked B_PAGING, it does not reside on * the vp's paging queues so we cannot call bdirty(). The * bp in this case is not an NFS cache block so we should * be safe. XXX */ if (error == EINTR || (!error && (bp->b_flags & B_NEEDCOMMIT))) { int s; s = splbio(); bp->b_flags &= ~(B_INVAL|B_NOCACHE); if ((bp->b_flags & B_PAGING) == 0) { bdirty(bp); bp->b_flags &= ~B_DONE; } if (error && (bp->b_flags & B_ASYNC) == 0) bp->b_flags |= B_EINTR; splx(s); } else { if (error) { bp->b_ioflags |= BIO_ERROR; bp->b_error = np->n_error = error; np->n_flag |= NWRITEERR; } bp->b_dirtyoff = bp->b_dirtyend = 0; } } else { bp->b_resid = 0; bufdone(bp); return (0); } } bp->b_resid = uiop->uio_resid; if (must_commit) nfs_clearcommit(vp->v_mount); bufdone(bp); return (error); } /* * Used to aid in handling ftruncate() operations on the NFS client side. * Truncation creates a number of special problems for NFS. We have to * throw away VM pages and buffer cache buffers that are beyond EOF, and * we have to properly handle VM pages or (potentially dirty) buffers * that straddle the truncation point. */ int nfs_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize) { struct nfsnode *np = VTONFS(vp); u_quad_t tsize = np->n_size; int biosize = vp->v_mount->mnt_stat.f_iosize; int error = 0; np->n_size = nsize; if (np->n_size < tsize) { struct buf *bp; daddr_t lbn; int bufsize; /* * vtruncbuf() doesn't get the buffer overlapping the * truncation point. We may have a B_DELWRI and/or B_CACHE * buffer that now needs to be truncated. */ error = vtruncbuf(vp, cred, td, nsize, biosize); lbn = nsize / biosize; bufsize = nsize & (biosize - 1); bp = nfs_getcacheblk(vp, lbn, bufsize, td); if (bp->b_dirtyoff > bp->b_bcount) bp->b_dirtyoff = bp->b_bcount; if (bp->b_dirtyend > bp->b_bcount) bp->b_dirtyend = bp->b_bcount; bp->b_flags |= B_RELBUF; /* don't leave garbage around */ brelse(bp); } else { vnode_pager_setsize(vp, nsize); } return(error); }