/*- * Copyright (c) 1993 * The Regents of the University of California. All rights reserved. * * 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. * * @(#)ufs_readwrite.c 8.11 (Berkeley) 5/8/95 * $FreeBSD: src/sys/ufs/ufs/ufs_readwrite.c,v 1.65.2.14 2003/04/04 22:21:29 tegge Exp $ * $DragonFly: src/sys/vfs/ufs/ufs_readwrite.c,v 1.26 2008/06/19 23:27:39 dillon Exp $ */ #define BLKSIZE(a, b, c) blksize(a, b, c) #define FS struct fs #define I_FS i_fs #include #include #include #include #include #include #include #include #include #include "opt_directio.h" #define VN_KNOTE(vp, b) \ KNOTE((struct klist *)&vp->v_pollinfo.vpi_selinfo.si_note, (b)) #ifdef DIRECTIO extern int ffs_rawread(struct vnode *vp, struct uio *uio, int *workdone); #endif SYSCTL_DECL(_vfs_ffs); static int getpages_uses_bufcache = 0; SYSCTL_INT(_vfs_ffs, OID_AUTO, getpages_uses_bufcache, CTLFLAG_RW, &getpages_uses_bufcache, 0, ""); /* * Vnode op for reading. * * ffs_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, * struct ucred *a_cred) */ /* ARGSUSED */ int ffs_read(struct vop_read_args *ap) { struct vnode *vp; struct inode *ip; struct uio *uio; FS *fs; struct buf *bp; off_t bytesinfile; int xfersize, blkoffset; int error, orig_resid; u_short mode; int seqcount; int ioflag; vp = ap->a_vp; seqcount = ap->a_ioflag >> 16; ip = VTOI(vp); mode = ip->i_mode; uio = ap->a_uio; ioflag = ap->a_ioflag; #ifdef DIRECTIO if ((ioflag & IO_DIRECT) != 0) { int workdone; error = ffs_rawread(vp, uio, &workdone); if (error || workdone) return error; } #endif #ifdef DIAGNOSTIC if (uio->uio_rw != UIO_READ) panic("ffs_read: mode"); if (vp->v_type == VLNK) { if ((int)ip->i_size < vp->v_mount->mnt_maxsymlinklen) panic("ffs_read: short symlink"); } else if (vp->v_type != VREG && vp->v_type != VDIR) panic("ffs_read: type %d", vp->v_type); #endif fs = ip->I_FS; if ((uint64_t)uio->uio_offset > fs->fs_maxfilesize) return (EFBIG); orig_resid = uio->uio_resid; if (orig_resid <= 0) return (0); bytesinfile = ip->i_size - uio->uio_offset; if (bytesinfile <= 0) { if ((vp->v_mount->mnt_flag & MNT_NOATIME) == 0) ip->i_flag |= IN_ACCESS; return 0; } /* * Ok so we couldn't do it all in one vm trick... * so cycle around trying smaller bites.. */ for (error = 0, bp = NULL; uio->uio_resid > 0; bp = NULL) { if ((bytesinfile = ip->i_size - uio->uio_offset) <= 0) break; error = ffs_blkatoff_ra(vp, uio->uio_offset, NULL, &bp, seqcount); if (error) break; /* * If IO_DIRECT then set B_DIRECT for the buffer. This * will cause us to attempt to release the buffer later on * and will cause the buffer cache to attempt to free the * underlying pages. */ if (ioflag & IO_DIRECT) bp->b_flags |= B_DIRECT; /* * We should only get non-zero b_resid when an I/O error * has occurred, which should cause us to break above. * However, if the short read did not cause an error, * then we want to ensure that we do not uiomove bad * or uninitialized data. * * XXX b_resid is only valid when an actual I/O has occured * and may be incorrect if the buffer is B_CACHE or if the * last op on the buffer was a failed write. This KASSERT * is a precursor to removing it from the UFS code. */ KASSERT(bp->b_resid == 0, ("bp->b_resid != 0")); /* * Calculate how much data we can copy */ blkoffset = blkoff(fs, uio->uio_offset); xfersize = bp->b_bufsize - blkoffset; if (xfersize > uio->uio_resid) xfersize = uio->uio_resid; if (xfersize > bytesinfile) xfersize = bytesinfile; if (xfersize <= 0) { panic("ufs_readwrite: impossible xfersize: %d", xfersize); } /* * otherwise use the general form */ error = uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio); if (error) break; if ((ioflag & (IO_VMIO|IO_DIRECT)) && (LIST_FIRST(&bp->b_dep) == NULL)) { /* * If there are no dependencies, and it's VMIO, * then we don't need the buf, mark it available * for freeing. The VM has the data. */ bp->b_flags |= B_RELBUF; brelse(bp); } else { /* * Otherwise let whoever * made the request take care of * freeing it. We just queue * it onto another list. */ bqrelse(bp); } } /* * This can only happen in the case of an error * because the loop above resets bp to NULL on each iteration * and on normal completion has not set a new value into it. * so it must have come from a 'break' statement */ if (bp != NULL) { if ((ioflag & (IO_VMIO|IO_DIRECT)) && (LIST_FIRST(&bp->b_dep) == NULL)) { bp->b_flags |= B_RELBUF; brelse(bp); } else { bqrelse(bp); } } if ((error == 0 || uio->uio_resid != orig_resid) && (vp->v_mount->mnt_flag & MNT_NOATIME) == 0) ip->i_flag |= IN_ACCESS; return (error); } /* * Vnode op for writing. * * ffs_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag, * struct ucred *a_cred) */ int ffs_write(struct vop_write_args *ap) { struct vnode *vp; struct uio *uio; struct inode *ip; FS *fs; struct buf *bp; ufs_daddr_t lbn; off_t osize; int seqcount; int blkoffset, error, extended, flags, ioflag, resid, size, xfersize; struct thread *td; extended = 0; seqcount = ap->a_ioflag >> 16; ioflag = ap->a_ioflag; uio = ap->a_uio; vp = ap->a_vp; ip = VTOI(vp); #ifdef DIAGNOSTIC if (uio->uio_rw != UIO_WRITE) panic("ffs_write: mode"); #endif switch (vp->v_type) { case VREG: if (ioflag & IO_APPEND) uio->uio_offset = ip->i_size; if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size) return (EPERM); /* FALLTHROUGH */ case VLNK: break; case VDIR: panic("ffs_write: dir write"); break; default: panic("ffs_write: type %p %d (%d,%d)", vp, (int)vp->v_type, (int)uio->uio_offset, (int)uio->uio_resid ); } fs = ip->I_FS; if (uio->uio_offset < 0 || (uint64_t)uio->uio_offset + uio->uio_resid > fs->fs_maxfilesize) { return (EFBIG); } /* * Maybe this should be above the vnode op call, but so long as * file servers have no limits, I don't think it matters. */ td = uio->uio_td; if (vp->v_type == VREG && td && td->td_proc && uio->uio_offset + uio->uio_resid > td->td_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) { lwpsignal(td->td_proc, td->td_lwp, SIGXFSZ); return (EFBIG); } resid = uio->uio_resid; osize = ip->i_size; /* * NOTE! These B_ flags are actually balloc-only flags, not buffer * flags. They are similar to the BA_ flags in fbsd. */ if (seqcount > B_SEQMAX) flags = B_SEQMAX << B_SEQSHIFT; else flags = seqcount << B_SEQSHIFT; if ((ioflag & IO_SYNC) && !DOINGASYNC(vp)) flags |= B_SYNC; for (error = 0; uio->uio_resid > 0;) { lbn = lblkno(fs, uio->uio_offset); blkoffset = blkoff(fs, uio->uio_offset); xfersize = fs->fs_bsize - blkoffset; if (uio->uio_resid < xfersize) xfersize = uio->uio_resid; if (uio->uio_offset + xfersize > ip->i_size) vnode_pager_setsize(vp, uio->uio_offset + xfersize); /* * We must perform a read-before-write if the transfer * size does not cover the entire buffer, or if doing * a dummy write to flush the buffer. */ if (xfersize < fs->fs_bsize || uio->uio_segflg == UIO_NOCOPY) flags |= B_CLRBUF; else flags &= ~B_CLRBUF; /* XXX is uio->uio_offset the right thing here? */ error = VOP_BALLOC(vp, uio->uio_offset, xfersize, ap->a_cred, flags, &bp); if (error != 0) break; /* * If the buffer is not valid and we did not clear garbage * out above, we have to do so here even though the write * covers the entire buffer in order to avoid a mmap()/write * race where another process may see the garbage prior to * the uiomove() for a write replacing it. */ if ((bp->b_flags & B_CACHE) == 0 && (flags & B_CLRBUF) == 0) vfs_bio_clrbuf(bp); if (ioflag & IO_DIRECT) bp->b_flags |= B_DIRECT; if ((ioflag & (IO_SYNC|IO_INVAL)) == (IO_SYNC|IO_INVAL)) bp->b_flags |= B_NOCACHE; if (uio->uio_offset + xfersize > ip->i_size) { ip->i_size = uio->uio_offset + xfersize; extended = 1; } size = BLKSIZE(fs, ip, lbn) - bp->b_resid; if (size < xfersize) xfersize = size; error = uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio); if ((ioflag & (IO_VMIO|IO_DIRECT)) && (LIST_FIRST(&bp->b_dep) == NULL)) { bp->b_flags |= B_RELBUF; } /* * If IO_SYNC each buffer is written synchronously. Otherwise * if we have a severe page deficiency write the buffer * asynchronously. Otherwise try to cluster, and if that * doesn't do it then either do an async write (if O_DIRECT), * or a delayed write (if not). */ if (ioflag & IO_SYNC) { (void)bwrite(bp); } else if (vm_page_count_severe() || buf_dirty_count_severe() || (ioflag & IO_ASYNC)) { bp->b_flags |= B_CLUSTEROK; bawrite(bp); } else if (xfersize + blkoffset == fs->fs_bsize) { if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) { bp->b_flags |= B_CLUSTEROK; cluster_write(bp, (off_t)ip->i_size, vp->v_mount->mnt_stat.f_iosize, seqcount); } else { bawrite(bp); } } else if (ioflag & IO_DIRECT) { bp->b_flags |= B_CLUSTEROK; bawrite(bp); } else { bp->b_flags |= B_CLUSTEROK; bdwrite(bp); } if (error || xfersize == 0) break; ip->i_flag |= IN_CHANGE | IN_UPDATE; } /* * If we successfully wrote any data, and we are not the superuser * we clear the setuid and setgid bits as a precaution against * tampering. */ if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0) ip->i_mode &= ~(ISUID | ISGID); if (resid > uio->uio_resid) VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0)); if (error) { if (ioflag & IO_UNIT) { (void)ffs_truncate(vp, osize, ioflag & IO_SYNC, ap->a_cred); uio->uio_offset -= resid - uio->uio_resid; uio->uio_resid = resid; } } else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) { error = ffs_update(vp, 1); } return (error); } /* * get page routine */ int ffs_getpages(struct vop_getpages_args *ap) { off_t foff, physoffset; int i, size, bsize; struct vnode *dp, *vp; vm_object_t obj; vm_pindex_t pindex, firstindex; vm_page_t mreq; int bbackwards, bforwards; int pbackwards, pforwards; int firstpage; off_t reqoffset; off_t doffset; int poff; int pcount; int rtval; int pagesperblock; /* * If set just use the system standard getpages which issues a * UIO_NOCOPY VOP_READ. */ if (getpages_uses_bufcache) { return vop_stdgetpages(ap); } pcount = round_page(ap->a_count) / PAGE_SIZE; mreq = ap->a_m[ap->a_reqpage]; firstindex = ap->a_m[0]->pindex; /* * if ANY DEV_BSIZE blocks are valid on a large filesystem block, * then the entire page is valid. Since the page may be mapped, * user programs might reference data beyond the actual end of file * occuring within the page. We have to zero that data. */ if (mreq->valid) { if (mreq->valid != VM_PAGE_BITS_ALL) vm_page_zero_invalid(mreq, TRUE); for (i = 0; i < pcount; i++) { if (i != ap->a_reqpage) { vm_page_free(ap->a_m[i]); } } return VM_PAGER_OK; } vp = ap->a_vp; obj = vp->v_object; bsize = vp->v_mount->mnt_stat.f_iosize; pindex = mreq->pindex; foff = IDX_TO_OFF(pindex) /* + ap->a_offset should be zero */; if (bsize < PAGE_SIZE) return vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count, ap->a_reqpage); /* * foff is the file offset of the required page * reqlblkno is the logical block that contains the page * poff is the bytes offset of the page in the logical block */ poff = (int)(foff % bsize); reqoffset = foff - poff; if (VOP_BMAP(vp, reqoffset, &doffset, &bforwards, &bbackwards, BUF_CMD_READ) || doffset == NOOFFSET ) { for (i = 0; i < pcount; i++) { if (i != ap->a_reqpage) vm_page_free(ap->a_m[i]); } if (doffset == NOOFFSET) { if ((mreq->flags & PG_ZERO) == 0) vm_page_zero_fill(mreq); vm_page_undirty(mreq); mreq->valid = VM_PAGE_BITS_ALL; return VM_PAGER_OK; } else { return VM_PAGER_ERROR; } } physoffset = doffset + poff; pagesperblock = bsize / PAGE_SIZE; /* * find the first page that is contiguous. * * bforwards and bbackwards are the number of contiguous bytes * available before and after the block offset. poff is the page * offset, in bytes, relative to the block offset. * * pforwards and pbackwards are the number of contiguous pages * relative to the requested page, non-inclusive of the requested * page (so a pbackwards and pforwards of 0 indicates just the * requested page). */ firstpage = 0; if (ap->a_count) { /* * Calculate pbackwards and clean up any requested * pages that are too far back. */ pbackwards = (poff + bbackwards) >> PAGE_SHIFT; if (ap->a_reqpage > pbackwards) { firstpage = ap->a_reqpage - pbackwards; for (i = 0; i < firstpage; i++) vm_page_free(ap->a_m[i]); } /* * Calculate pforwards */ pforwards = (bforwards - poff - PAGE_SIZE) >> PAGE_SHIFT; if (pforwards < 0) pforwards = 0; if (pforwards < (pcount - (ap->a_reqpage + 1))) { for(i = ap->a_reqpage + pforwards + 1; i < pcount; i++) vm_page_free(ap->a_m[i]); pcount = ap->a_reqpage + pforwards + 1; } /* * Adjust pcount to be relative to firstpage. All pages prior * to firstpage in the array have been cleaned up. */ pcount -= firstpage; } /* * calculate the size of the transfer */ size = pcount * PAGE_SIZE; if ((IDX_TO_OFF(ap->a_m[firstpage]->pindex) + size) > vp->v_filesize) { size = vp->v_filesize - IDX_TO_OFF(ap->a_m[firstpage]->pindex); } physoffset -= foff; dp = VTOI(ap->a_vp)->i_devvp; rtval = VOP_GETPAGES(dp, &ap->a_m[firstpage], size, (ap->a_reqpage - firstpage), physoffset); return (rtval); }