/* * Copyright (c) 1989, 1990, 1993, 1994 * 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. 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. * * @(#)mfs_vfsops.c 8.11 (Berkeley) 6/19/95 * $FreeBSD: src/sys/ufs/mfs/mfs_vfsops.c,v 1.81.2.3 2001/07/04 17:35:21 tegge Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "mfsnode.h" #include "mfs_extern.h" MALLOC_DEFINE(M_MFSNODE, "MFS node", "MFS vnode private part"); static int mfs_mount (struct mount *mp, char *path, caddr_t data, struct ucred *td); static int mfs_start (struct mount *mp, int flags); static int mfs_statfs (struct mount *mp, struct statfs *sbp, struct ucred *cred); static int mfs_init (struct vfsconf *); static void mfs_doio(struct bio *bio, struct mfsnode *mfsp); d_open_t mfsopen; d_close_t mfsclose; d_strategy_t mfsstrategy; static struct dev_ops mfs_ops = { { "MFS", -1, D_DISK | D_NOEMERGPGR }, .d_open = mfsopen, .d_close = mfsclose, .d_read = physread, .d_write = physwrite, .d_strategy = mfsstrategy, }; /* * mfs vfs operations. */ static struct vfsops mfs_vfsops = { .vfs_flags = 0, .vfs_mount = mfs_mount, .vfs_start = mfs_start, .vfs_unmount = ffs_unmount, .vfs_root = ufs_root, .vfs_quotactl = ufs_quotactl, .vfs_statfs = mfs_statfs, .vfs_sync = ffs_sync, .vfs_vget = ffs_vget, .vfs_fhtovp = ffs_fhtovp, .vfs_checkexp = ufs_check_export, .vfs_vptofh = ffs_vptofh, .vfs_init = mfs_init }; VFS_SET(mfs_vfsops, mfs, 0); MODULE_VERSION(mfs, 1); /* * We allow the underlying MFS block device to be opened and read. */ int mfsopen(struct dev_open_args *ap) { cdev_t dev = ap->a_head.a_dev; #if 0 if (ap->a_oflags & FWRITE) return(EROFS); #endif if (dev->si_drv1) return(0); return(ENXIO); } int mfsclose(struct dev_close_args *ap) { cdev_t dev = ap->a_head.a_dev; struct mfsnode *mfsp; if ((mfsp = dev->si_drv1) == NULL) return(0); mfsp->mfs_active = 0; wakeup((caddr_t)mfsp); return(0); } int mfsstrategy(struct dev_strategy_args *ap) { cdev_t dev = ap->a_head.a_dev; struct bio *bio = ap->a_bio; struct buf *bp = bio->bio_buf; off_t boff = bio->bio_offset; off_t eoff = boff + bp->b_bcount; struct mfsnode *mfsp; if ((mfsp = dev->si_drv1) == NULL) { bp->b_error = ENXIO; goto error; } if (boff < 0) goto bad; if (eoff > mfsp->mfs_size) { if (boff > mfsp->mfs_size || (bp->b_flags & B_BNOCLIP)) goto bad; /* * Return EOF by completing the I/O with 0 bytes transfered. * Set B_INVAL to indicate that any data in the buffer is not * valid. */ if (boff == mfsp->mfs_size) { bp->b_resid = bp->b_bcount; bp->b_flags |= B_INVAL; goto done; } bp->b_bcount = mfsp->mfs_size - boff; } /* * Initiate I/O */ if (mfsp->mfs_td == curthread) { mfs_doio(bio, mfsp); } else { bioq_insert_tail(&mfsp->bio_queue, bio); wakeup((caddr_t)mfsp); } return(0); /* * Failure conditions on bio */ bad: bp->b_error = EINVAL; error: bp->b_flags |= B_ERROR | B_INVAL; done: biodone(bio); return(0); } /* * mfs_mount * * Called when mounting local physical media * * PARAMETERS: * mountroot * mp mount point structure * path NULL (flag for root mount!!!) * data * ndp * p process (user credentials check [statfs]) * * mount * mp mount point structure * path path to mount point * data pointer to argument struct in user space * ndp mount point namei() return (used for * credentials on reload), reused to look * up block device. * p process (user credentials check) * * RETURNS: 0 Success * !0 error number (errno.h) * * LOCK STATE: * * ENTRY * mount point is locked * EXIT * mount point is locked * * NOTES: * A NULL path can be used for a flag since the mount * system call will fail with EFAULT in copyinstr in * namei() if it is a genuine NULL from the user. */ /* ARGSUSED */ static int mfs_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred) { struct vnode *devvp; struct mfs_args args; struct ufsmount *ump; struct fs *fs; struct mfsnode *mfsp; struct nlookupdata nd; size_t size; char devname[16]; int flags; int minnum; int error; cdev_t dev; /* * Use NULL path to flag a root mount */ if (path == NULL) { /* *** * Mounting root file system *** */ /* you lose */ panic("mfs_mount: mount MFS as root: not configured!"); } mfsp = NULL; /* *** * Mounting non-root file system or updating a file system *** */ /* copy in user arguments*/ error = copyin(data, (caddr_t)&args, sizeof (struct mfs_args)); if (error) goto error_1; /* * If updating, check whether changing from read-only to * read/write; if there is no device name, that's all we do. */ if (mp->mnt_flag & MNT_UPDATE) { /* ******************** * UPDATE ******************** */ ump = VFSTOUFS(mp); fs = ump->um_fs; if (fs->fs_ronly == 0 && (mp->mnt_flag & MNT_RDONLY)) { flags = WRITECLOSE; if (mp->mnt_flag & MNT_FORCE) flags |= FORCECLOSE; error = ffs_flushfiles(mp, flags); if (error) goto error_1; } if (fs->fs_ronly && (mp->mnt_kern_flag & MNTK_WANTRDWR)) { /* XXX reopen the device vnode read-write */ fs->fs_ronly = 0; } /* if not updating name...*/ if (args.fspec == 0) { /* * Process export requests. Jumping to "success" * will return the vfs_export() error code. */ error = vfs_export(mp, &ump->um_export, &args.export); goto success; } /* XXX MFS does not support name updating*/ goto success; } /* * Do the MALLOC before the make_dev since doing so afterward * might cause a bogus v_data pointer to get dereferenced * elsewhere if MALLOC should block. */ mfsp = kmalloc(sizeof *mfsp, M_MFSNODE, M_WAITOK | M_ZERO); minnum = (int)curproc->p_pid; dev = make_dev(&mfs_ops, minnum, UID_ROOT, GID_WHEEL, 0600, "mfs%d", minnum); /* It is not clear that these will get initialized otherwise */ dev->si_bsize_phys = DEV_BSIZE; dev->si_iosize_max = MAXPHYS; dev->si_drv1 = mfsp; mfsp->mfs_baseoff = args.base; mfsp->mfs_size = args.size; mfsp->mfs_dev = dev; mfsp->mfs_td = curthread; mfsp->mfs_active = 1; bioq_init(&mfsp->bio_queue); devfs_config(); /* sync devfs work */ ksnprintf(devname, sizeof(devname), "/dev/mfs%d", minnum); nlookup_init(&nd, devname, UIO_SYSSPACE, 0); devvp = NULL; error = nlookup(&nd); if (error == 0) { devvp = nd.nl_nch.ncp->nc_vp; if (devvp == NULL) error = ENOENT; error = vget(devvp, LK_SHARED); } nlookup_done(&nd); if (error) goto error_1; vn_unlock(devvp); /* * Our 'block' device must be backed by a VM object. Theoretically * we could use the anonymous memory VM object supplied by userland, * but it would be somewhat of a complex task to deal with it * that way since it would result in I/O requests which supply * the VM pages from our own object. * * vnode_pager_alloc() is typically called when a VM object is * being referenced externally. We have to undo the refs for * the self reference between vnode and object. */ vnode_pager_setsize(devvp, args.size); /* Save "mounted from" info for mount point (NULL pad)*/ copyinstr(args.fspec, /* device name*/ mp->mnt_stat.f_mntfromname, /* save area*/ MNAMELEN - 1, /* max size*/ &size); /* real size*/ bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); /* vref is eaten by mount? */ error = ffs_mountfs(devvp, mp, M_MFSNODE); if (error) { mfsp->mfs_active = 0; goto error_2; } /* * Initialize FS stat information in mount struct; uses * mp->mnt_stat.f_mntfromname. * * This code is common to root and non-root mounts */ VFS_STATFS(mp, &mp->mnt_stat, cred); /* * Mark VFS_START MPSAFE; this is to avoid accessing * per-mount token after VFS_START exits */ mp->mnt_kern_flag |= MNTK_ST_MPSAFE; goto success; error_2: /* error with devvp held*/ vrele(devvp); error_1: /* no state to back out*/ if (mfsp) { if (mfsp->mfs_dev) { destroy_dev(mfsp->mfs_dev); mfsp->mfs_dev = NULL; } kfree(mfsp, M_MFSNODE); } success: return(error); } /* * Used to grab the process and keep it in the kernel to service * memory filesystem I/O requests. * * Loop servicing I/O requests. * Copy the requested data into or out of the memory filesystem * address space. */ /* ARGSUSED */ static int mfs_start(struct mount *mp, int flags) { struct vnode *vp = VFSTOUFS(mp)->um_devvp; struct mfsnode *mfsp = vp->v_rdev->si_drv1; struct bio *bio; struct buf *bp; int gotsig = 0, sig; thread_t td = curthread; /* * We must prevent the system from trying to swap * out or kill ( when swap space is low, see vm/pageout.c ) the * process. A deadlock can occur if the process is swapped out, * and the system can loop trying to kill the unkillable ( while * references exist ) MFS process when swap space is low. */ KKASSERT(curproc); PHOLD(curproc); mfsp->mfs_td = td; while (mfsp->mfs_active) { crit_enter(); while ((bio = bioq_takefirst(&mfsp->bio_queue)) != NULL) { crit_exit(); bp = bio->bio_buf; mfs_doio(bio, mfsp); wakeup(bp); crit_enter(); } crit_exit(); /* * If a non-ignored signal is received, try to unmount. * If that fails, clear the signal (it has been "processed"), * otherwise we will loop here, as tsleep will always return * EINTR/ERESTART. */ /* * Note that dounmount() may fail if work was queued after * we slept. We have to jump hoops here to make sure that we * process any buffers after the sleep, before we dounmount() */ if (gotsig) { gotsig = 0; if (dounmount(mp, 0, 0) != 0) { KKASSERT(td->td_proc); lwkt_gettoken(&td->td_proc->p_token); sig = CURSIG(td->td_lwp); if (sig) { spin_lock(&td->td_lwp->lwp_spin); lwp_delsig(td->td_lwp, sig, 1); spin_unlock(&td->td_lwp->lwp_spin); } lwkt_reltoken(&td->td_proc->p_token); } } else if (tsleep((caddr_t)mfsp, PCATCH, "mfsidl", 0)) gotsig++; /* try to unmount in next pass */ } PRELE(curproc); if (mfsp->mfs_dev) { destroy_dev(mfsp->mfs_dev); mfsp->mfs_dev = NULL; } kfree(mfsp, M_MFSNODE); return (EMOUNTEXIT); } /* * Get file system statistics. */ static int mfs_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred) { int error; error = ffs_statfs(mp, sbp, cred); sbp->f_type = mp->mnt_vfc->vfc_typenum; return (error); } /* * Memory based filesystem initialization. */ static int mfs_init(struct vfsconf *vfsp) { return (0); } /* * Memory file system I/O. * * Trivial on the HP since buffer has already been mapping into KVA space. * * Read and Write are handled with a simple copyin and copyout. * * We also partially support VOP_FREEBLKS(). We can't implement * completely -- for example, on fragments or inode metadata, but we can * implement it for page-aligned requests. */ static void mfs_doio(struct bio *bio, struct mfsnode *mfsp) { struct buf *bp = bio->bio_buf; caddr_t base = mfsp->mfs_baseoff + bio->bio_offset; int bytes; switch(bp->b_cmd) { case BUF_CMD_FREEBLKS: /* * Implement FREEBLKS, which allows the filesystem to tell * a block device when blocks are no longer needed (like when * a file is deleted). We use the hook to MADV_FREE the VM. * This makes an MFS filesystem work as well or better then * a sun-style swap-mounted filesystem. */ bytes = bp->b_bcount; if ((vm_offset_t)base & PAGE_MASK) { int n = PAGE_SIZE - ((vm_offset_t)base & PAGE_MASK); bytes -= n; base += n; } if (bytes > 0) { struct madvise_args uap; bytes &= ~PAGE_MASK; if (bytes != 0) { struct sysmsg sysmsg; bzero(&sysmsg, sizeof(sysmsg)); bzero(&uap, sizeof(uap)); uap.addr = base; uap.len = bytes; uap.behav = MADV_FREE; sys_madvise(&sysmsg, &uap); } } bp->b_error = 0; break; case BUF_CMD_READ: /* * Read data from our 'memory' disk */ bp->b_error = copyin(base, bp->b_data, bp->b_bcount); break; case BUF_CMD_WRITE: /* * Write data to our 'memory' disk */ bp->b_error = copyout(bp->b_data, base, bp->b_bcount); break; default: panic("mfs: bad b_cmd %d", bp->b_cmd); } if (bp->b_error) bp->b_flags |= B_ERROR; biodone(bio); }