diff options
Diffstat (limited to 'sys/kern/vfs_default.c')
| -rw-r--r-- | sys/kern/vfs_default.c | 845 |
1 files changed, 845 insertions, 0 deletions
diff --git a/sys/kern/vfs_default.c b/sys/kern/vfs_default.c new file mode 100644 index 0000000..6bfe085 --- /dev/null +++ b/sys/kern/vfs_default.c @@ -0,0 +1,845 @@ +/* + * Copyright (c) 1989, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed + * to Berkeley by John Heidemann of the UCLA Ficus project. + * + * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project + * + * 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. + * + * + * $FreeBSD$ + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/bio.h> +#include <sys/buf.h> +#include <sys/conf.h> +#include <sys/kernel.h> +#include <sys/lock.h> +#include <sys/malloc.h> +#include <sys/mount.h> +#include <sys/mutex.h> +#include <sys/unistd.h> +#include <sys/vnode.h> +#include <sys/poll.h> + +#include <machine/limits.h> + +#include <vm/vm.h> +#include <vm/vm_object.h> +#include <vm/vm_extern.h> +#include <vm/pmap.h> +#include <vm/vm_map.h> +#include <vm/vm_page.h> +#include <vm/vm_pager.h> +#include <vm/vnode_pager.h> + +static int vop_nolookup(struct vop_lookup_args *); +static int vop_nostrategy(struct vop_strategy_args *); + +/* + * This vnode table stores what we want to do if the filesystem doesn't + * implement a particular VOP. + * + * If there is no specific entry here, we will return EOPNOTSUPP. + * + */ + +vop_t **default_vnodeop_p; +static struct vnodeopv_entry_desc default_vnodeop_entries[] = { + { &vop_default_desc, (vop_t *) vop_eopnotsupp }, + { &vop_advlock_desc, (vop_t *) vop_einval }, + { &vop_bmap_desc, (vop_t *) vop_stdbmap }, + { &vop_close_desc, (vop_t *) vop_null }, + { &vop_createvobject_desc, (vop_t *) vop_stdcreatevobject }, + { &vop_destroyvobject_desc, (vop_t *) vop_stddestroyvobject }, + { &vop_fsync_desc, (vop_t *) vop_null }, + { &vop_getpages_desc, (vop_t *) vop_stdgetpages }, + { &vop_getvobject_desc, (vop_t *) vop_stdgetvobject }, + { &vop_inactive_desc, (vop_t *) vop_stdinactive }, + { &vop_ioctl_desc, (vop_t *) vop_enotty }, + { &vop_islocked_desc, (vop_t *) vop_noislocked }, + { &vop_lease_desc, (vop_t *) vop_null }, + { &vop_lock_desc, (vop_t *) vop_nolock }, + { &vop_lookup_desc, (vop_t *) vop_nolookup }, + { &vop_open_desc, (vop_t *) vop_null }, + { &vop_pathconf_desc, (vop_t *) vop_einval }, + { &vop_putpages_desc, (vop_t *) vop_stdputpages }, + { &vop_poll_desc, (vop_t *) vop_nopoll }, + { &vop_readlink_desc, (vop_t *) vop_einval }, + { &vop_revoke_desc, (vop_t *) vop_revoke }, + { &vop_strategy_desc, (vop_t *) vop_nostrategy }, + { &vop_unlock_desc, (vop_t *) vop_nounlock }, + { NULL, NULL } +}; + +static struct vnodeopv_desc default_vnodeop_opv_desc = + { &default_vnodeop_p, default_vnodeop_entries }; + +VNODEOP_SET(default_vnodeop_opv_desc); + +/* + * Series of placeholder functions for various error returns for + * VOPs. + */ + +int +vop_eopnotsupp(struct vop_generic_args *ap) +{ + /* + printf("vop_notsupp[%s]\n", ap->a_desc->vdesc_name); + */ + + return (EOPNOTSUPP); +} + +int +vop_ebadf(struct vop_generic_args *ap) +{ + + return (EBADF); +} + +int +vop_enotty(struct vop_generic_args *ap) +{ + + return (ENOTTY); +} + +int +vop_einval(struct vop_generic_args *ap) +{ + + return (EINVAL); +} + +int +vop_null(struct vop_generic_args *ap) +{ + + return (0); +} + +/* + * Used to make a defined VOP fall back to the default VOP. + */ +int +vop_defaultop(struct vop_generic_args *ap) +{ + + return (VOCALL(default_vnodeop_p, ap->a_desc->vdesc_offset, ap)); +} + +/* + * Helper function to panic on some bad VOPs in some filesystems. + */ +int +vop_panic(struct vop_generic_args *ap) +{ + + panic("filesystem goof: vop_panic[%s]", ap->a_desc->vdesc_name); +} + +/* + * vop_std<something> and vop_no<something> are default functions for use by + * filesystems that need the "default reasonable" implementation for a + * particular operation. + * + * The documentation for the operations they implement exists (if it exists) + * in the VOP_<SOMETHING>(9) manpage (all uppercase). + */ + +/* + * Default vop for filesystems that do not support name lookup + */ +static int +vop_nolookup(ap) + struct vop_lookup_args /* { + struct vnode *a_dvp; + struct vnode **a_vpp; + struct componentname *a_cnp; + } */ *ap; +{ + + *ap->a_vpp = NULL; + return (ENOTDIR); +} + +/* + * vop_nostrategy: + * + * Strategy routine for VFS devices that have none. + * + * BIO_ERROR and B_INVAL must be cleared prior to calling any strategy + * routine. Typically this is done for a BIO_READ strategy call. + * Typically B_INVAL is assumed to already be clear prior to a write + * and should not be cleared manually unless you just made the buffer + * invalid. BIO_ERROR should be cleared either way. + */ + +static int +vop_nostrategy (struct vop_strategy_args *ap) +{ + printf("No strategy for buffer at %p\n", ap->a_bp); + vprint("", ap->a_vp); + vprint("", ap->a_bp->b_vp); + ap->a_bp->b_ioflags |= BIO_ERROR; + ap->a_bp->b_error = EOPNOTSUPP; + bufdone(ap->a_bp); + return (EOPNOTSUPP); +} + +/* + * vop_stdpathconf: + * + * Standard implementation of POSIX pathconf, to get information about limits + * for a filesystem. + * Override per filesystem for the case where the filesystem has smaller + * limits. + */ +int +vop_stdpathconf(ap) + struct vop_pathconf_args /* { + struct vnode *a_vp; + int a_name; + int *a_retval; + } */ *ap; +{ + + switch (ap->a_name) { + case _PC_LINK_MAX: + *ap->a_retval = LINK_MAX; + return (0); + case _PC_MAX_CANON: + *ap->a_retval = MAX_CANON; + return (0); + case _PC_MAX_INPUT: + *ap->a_retval = MAX_INPUT; + return (0); + case _PC_PIPE_BUF: + *ap->a_retval = PIPE_BUF; + return (0); + case _PC_CHOWN_RESTRICTED: + *ap->a_retval = 1; + return (0); + case _PC_VDISABLE: + *ap->a_retval = _POSIX_VDISABLE; + return (0); + default: + return (EINVAL); + } + /* NOTREACHED */ +} + +/* + * Standard lock, unlock and islocked functions. + */ +int +vop_stdlock(ap) + struct vop_lock_args /* { + struct vnode *a_vp; + int a_flags; + struct thread *a_td; + } */ *ap; +{ + struct vnode *vp = ap->a_vp; + +#ifndef DEBUG_LOCKS + return (lockmgr(&vp->v_lock, ap->a_flags, &vp->v_interlock, ap->a_td)); +#else + return (debuglockmgr(&vp->v_lock, ap->a_flags, &vp->v_interlock, + ap->a_td, "vop_stdlock", vp->filename, vp->line)); +#endif +} + +/* See above. */ +int +vop_stdunlock(ap) + struct vop_unlock_args /* { + struct vnode *a_vp; + int a_flags; + struct thread *a_td; + } */ *ap; +{ + struct vnode *vp = ap->a_vp; + + return (lockmgr(&vp->v_lock, ap->a_flags | LK_RELEASE, &vp->v_interlock, + ap->a_td)); +} + +/* See above. */ +int +vop_stdislocked(ap) + struct vop_islocked_args /* { + struct vnode *a_vp; + struct thread *a_td; + } */ *ap; +{ + + return (lockstatus(&ap->a_vp->v_lock, ap->a_td)); +} + +/* Mark the vnode inactive */ +int +vop_stdinactive(ap) + struct vop_inactive_args /* { + struct vnode *a_vp; + struct thread *a_td; + } */ *ap; +{ + + VOP_UNLOCK(ap->a_vp, 0, ap->a_td); + return (0); +} + +/* + * Return true for select/poll. + */ +int +vop_nopoll(ap) + struct vop_poll_args /* { + struct vnode *a_vp; + int a_events; + struct ucred *a_cred; + struct thread *a_td; + } */ *ap; +{ + /* + * Return true for read/write. If the user asked for something + * special, return POLLNVAL, so that clients have a way of + * determining reliably whether or not the extended + * functionality is present without hard-coding knowledge + * of specific filesystem implementations. + */ + if (ap->a_events & ~POLLSTANDARD) + return (POLLNVAL); + + return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); +} + +/* + * Implement poll for local filesystems that support it. + */ +int +vop_stdpoll(ap) + struct vop_poll_args /* { + struct vnode *a_vp; + int a_events; + struct ucred *a_cred; + struct thread *a_td; + } */ *ap; +{ + if (ap->a_events & ~POLLSTANDARD) + return (vn_pollrecord(ap->a_vp, ap->a_td, ap->a_events)); + return (ap->a_events & (POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM)); +} + +/* + * Stubs to use when there is no locking to be done on the underlying object. + * A minimal shared lock is necessary to ensure that the underlying object + * is not revoked while an operation is in progress. So, an active shared + * count is maintained in an auxillary vnode lock structure. + */ +int +vop_sharedlock(ap) + struct vop_lock_args /* { + struct vnode *a_vp; + int a_flags; + struct thread *a_td; + } */ *ap; +{ + /* + * This code cannot be used until all the non-locking filesystems + * (notably NFS) are converted to properly lock and release nodes. + * Also, certain vnode operations change the locking state within + * the operation (create, mknod, remove, link, rename, mkdir, rmdir, + * and symlink). Ideally these operations should not change the + * lock state, but should be changed to let the caller of the + * function unlock them. Otherwise all intermediate vnode layers + * (such as union, umapfs, etc) must catch these functions to do + * the necessary locking at their layer. Note that the inactive + * and lookup operations also change their lock state, but this + * cannot be avoided, so these two operations will always need + * to be handled in intermediate layers. + */ + struct vnode *vp = ap->a_vp; + int vnflags, flags = ap->a_flags; + + switch (flags & LK_TYPE_MASK) { + case LK_DRAIN: + vnflags = LK_DRAIN; + break; + case LK_EXCLUSIVE: +#ifdef DEBUG_VFS_LOCKS + /* + * Normally, we use shared locks here, but that confuses + * the locking assertions. + */ + vnflags = LK_EXCLUSIVE; + break; +#endif + case LK_SHARED: + vnflags = LK_SHARED; + break; + case LK_UPGRADE: + case LK_EXCLUPGRADE: + case LK_DOWNGRADE: + return (0); + case LK_RELEASE: + default: + panic("vop_sharedlock: bad operation %d", flags & LK_TYPE_MASK); + } + if (flags & LK_INTERLOCK) + vnflags |= LK_INTERLOCK; +#ifndef DEBUG_LOCKS + return (lockmgr(&vp->v_lock, vnflags, &vp->v_interlock, ap->a_td)); +#else + return (debuglockmgr(&vp->v_lock, vnflags, &vp->v_interlock, ap->a_td, + "vop_sharedlock", vp->filename, vp->line)); +#endif +} + +/* + * Stubs to use when there is no locking to be done on the underlying object. + * A minimal shared lock is necessary to ensure that the underlying object + * is not revoked while an operation is in progress. So, an active shared + * count is maintained in an auxillary vnode lock structure. + */ +int +vop_nolock(ap) + struct vop_lock_args /* { + struct vnode *a_vp; + int a_flags; + struct thread *a_td; + } */ *ap; +{ +#ifdef notyet + /* + * This code cannot be used until all the non-locking filesystems + * (notably NFS) are converted to properly lock and release nodes. + * Also, certain vnode operations change the locking state within + * the operation (create, mknod, remove, link, rename, mkdir, rmdir, + * and symlink). Ideally these operations should not change the + * lock state, but should be changed to let the caller of the + * function unlock them. Otherwise all intermediate vnode layers + * (such as union, umapfs, etc) must catch these functions to do + * the necessary locking at their layer. Note that the inactive + * and lookup operations also change their lock state, but this + * cannot be avoided, so these two operations will always need + * to be handled in intermediate layers. + */ + struct vnode *vp = ap->a_vp; + int vnflags, flags = ap->a_flags; + + switch (flags & LK_TYPE_MASK) { + case LK_DRAIN: + vnflags = LK_DRAIN; + break; + case LK_EXCLUSIVE: + case LK_SHARED: + vnflags = LK_SHARED; + break; + case LK_UPGRADE: + case LK_EXCLUPGRADE: + case LK_DOWNGRADE: + return (0); + case LK_RELEASE: + default: + panic("vop_nolock: bad operation %d", flags & LK_TYPE_MASK); + } + if (flags & LK_INTERLOCK) + vnflags |= LK_INTERLOCK; + return(lockmgr(&vp->v_lock, vnflags, &vp->v_interlock, ap->a_td)); +#else /* for now */ + /* + * Since we are not using the lock manager, we must clear + * the interlock here. + */ + if (ap->a_flags & LK_INTERLOCK) + mtx_unlock(&ap->a_vp->v_interlock); + return (0); +#endif +} + +/* + * Do the inverse of vop_nolock, handling the interlock in a compatible way. + */ +int +vop_nounlock(ap) + struct vop_unlock_args /* { + struct vnode *a_vp; + int a_flags; + struct thread *a_td; + } */ *ap; +{ + + /* + * Since we are not using the lock manager, we must clear + * the interlock here. + */ + if (ap->a_flags & LK_INTERLOCK) + mtx_unlock(&ap->a_vp->v_interlock); + return (0); +} + +/* + * Return whether or not the node is in use. + */ +int +vop_noislocked(ap) + struct vop_islocked_args /* { + struct vnode *a_vp; + struct thread *a_td; + } */ *ap; +{ + + return (0); +} + +/* + * Return our mount point, as we will take charge of the writes. + */ +int +vop_stdgetwritemount(ap) + struct vop_getwritemount_args /* { + struct vnode *a_vp; + struct mount **a_mpp; + } */ *ap; +{ + + *(ap->a_mpp) = ap->a_vp->v_mount; + return (0); +} + +/* Create the VM system backing object for this vnode */ +int +vop_stdcreatevobject(ap) + struct vop_createvobject_args /* { + struct vnode *vp; + struct ucred *cred; + struct thread *td; + } */ *ap; +{ + struct vnode *vp = ap->a_vp; + struct ucred *cred = ap->a_cred; + struct thread *td = ap->a_td; + struct vattr vat; + vm_object_t object; + int error = 0; + + GIANT_REQUIRED; + + if (!vn_isdisk(vp, NULL) && vn_canvmio(vp) == FALSE) + return (0); + +retry: + if ((object = vp->v_object) == NULL) { + if (vp->v_type == VREG || vp->v_type == VDIR) { + if ((error = VOP_GETATTR(vp, &vat, cred, td)) != 0) + goto retn; + object = vnode_pager_alloc(vp, vat.va_size, 0, 0); + } else if (devsw(vp->v_rdev) != NULL) { + /* + * This simply allocates the biggest object possible + * for a disk vnode. This should be fixed, but doesn't + * cause any problems (yet). + */ + object = vnode_pager_alloc(vp, IDX_TO_OFF(INT_MAX), 0, 0); + } else { + goto retn; + } + /* + * Dereference the reference we just created. This assumes + * that the object is associated with the vp. + */ + object->ref_count--; + vp->v_usecount--; + } else { + if (object->flags & OBJ_DEAD) { + VOP_UNLOCK(vp, 0, td); + tsleep(object, PVM, "vodead", 0); + vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td); + goto retry; + } + } + + KASSERT(vp->v_object != NULL, ("vfs_object_create: NULL object")); + vp->v_flag |= VOBJBUF; + +retn: + return (error); +} + +/* Destroy the VM system object associated with this vnode */ +int +vop_stddestroyvobject(ap) + struct vop_destroyvobject_args /* { + struct vnode *vp; + } */ *ap; +{ + struct vnode *vp = ap->a_vp; + vm_object_t obj = vp->v_object; + + GIANT_REQUIRED; + + if (vp->v_object == NULL) + return (0); + + if (obj->ref_count == 0) { + /* + * vclean() may be called twice. The first time + * removes the primary reference to the object, + * the second time goes one further and is a + * special-case to terminate the object. + * + * don't double-terminate the object + */ + if ((obj->flags & OBJ_DEAD) == 0) + vm_object_terminate(obj); + } else { + /* + * Woe to the process that tries to page now :-). + */ + vm_pager_deallocate(obj); + } + return (0); +} + +/* + * Return the underlying VM object. This routine may be called with or + * without the vnode interlock held. If called without, the returned + * object is not guarenteed to be valid. The syncer typically gets the + * object without holding the interlock in order to quickly test whether + * it might be dirty before going heavy-weight. vm_object's use zalloc + * and thus stable-storage, so this is safe. + */ +int +vop_stdgetvobject(ap) + struct vop_getvobject_args /* { + struct vnode *vp; + struct vm_object **objpp; + } */ *ap; +{ + struct vnode *vp = ap->a_vp; + struct vm_object **objpp = ap->a_objpp; + + if (objpp) + *objpp = vp->v_object; + return (vp->v_object ? 0 : EINVAL); +} + +/* XXX Needs good comment and VOP_BMAP(9) manpage */ +int +vop_stdbmap(ap) + struct vop_bmap_args /* { + struct vnode *a_vp; + daddr_t a_bn; + struct vnode **a_vpp; + daddr_t *a_bnp; + int *a_runp; + int *a_runb; + } */ *ap; +{ + + if (ap->a_vpp != NULL) + *ap->a_vpp = ap->a_vp; + if (ap->a_bnp != NULL) + *ap->a_bnp = ap->a_bn * btodb(ap->a_vp->v_mount->mnt_stat.f_iosize); + if (ap->a_runp != NULL) + *ap->a_runp = 0; + if (ap->a_runb != NULL) + *ap->a_runb = 0; + return (0); +} + +/* XXX Needs good comment and more info in the manpage (VOP_GETPAGES(9)). */ +int +vop_stdgetpages(ap) + struct vop_getpages_args /* { + struct vnode *a_vp; + vm_page_t *a_m; + int a_count; + int a_reqpage; + vm_ooffset_t a_offset; + } */ *ap; +{ + + return vnode_pager_generic_getpages(ap->a_vp, ap->a_m, + ap->a_count, ap->a_reqpage); +} + +/* XXX Needs good comment and more info in the manpage (VOP_PUTPAGES(9)). */ +int +vop_stdputpages(ap) + struct vop_putpages_args /* { + struct vnode *a_vp; + vm_page_t *a_m; + int a_count; + int a_sync; + int *a_rtvals; + vm_ooffset_t a_offset; + } */ *ap; +{ + + return vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count, + ap->a_sync, ap->a_rtvals); +} + + + +/* + * vfs default ops + * used to fill the vfs function table to get reasonable default return values. + */ +int +vfs_stdmount (mp, path, data, ndp, td) + struct mount *mp; + char *path; + caddr_t data; + struct nameidata *ndp; + struct thread *td; +{ + return (0); +} + +int +vfs_stdunmount (mp, mntflags, td) + struct mount *mp; + int mntflags; + struct thread *td; +{ + return (0); +} + +int +vfs_stdroot (mp, vpp) + struct mount *mp; + struct vnode **vpp; +{ + return (EOPNOTSUPP); +} + +int +vfs_stdstatfs (mp, sbp, td) + struct mount *mp; + struct statfs *sbp; + struct thread *td; +{ + return (EOPNOTSUPP); +} + +int +vfs_stdvptofh (vp, fhp) + struct vnode *vp; + struct fid *fhp; +{ + return (EOPNOTSUPP); +} + +int +vfs_stdstart (mp, flags, td) + struct mount *mp; + int flags; + struct thread *td; +{ + return (0); +} + +int +vfs_stdquotactl (mp, cmds, uid, arg, td) + struct mount *mp; + int cmds; + uid_t uid; + caddr_t arg; + struct thread *td; +{ + return (EOPNOTSUPP); +} + +int +vfs_stdsync (mp, waitfor, cred, td) + struct mount *mp; + int waitfor; + struct ucred *cred; + struct thread *td; +{ + return (0); +} + +int +vfs_stdvget (mp, ino, flags, vpp) + struct mount *mp; + ino_t ino; + int flags; + struct vnode **vpp; +{ + return (EOPNOTSUPP); +} + +int +vfs_stdfhtovp (mp, fhp, vpp) + struct mount *mp; + struct fid *fhp; + struct vnode **vpp; +{ + return (EOPNOTSUPP); +} + +int +vfs_stdinit (vfsp) + struct vfsconf *vfsp; +{ + return (0); +} + +int +vfs_stduninit (vfsp) + struct vfsconf *vfsp; +{ + return(0); +} + +int +vfs_stdextattrctl(mp, cmd, filename_vp, attrnamespace, attrname, td) + struct mount *mp; + int cmd; + struct vnode *filename_vp; + int attrnamespace; + const char *attrname; + struct thread *td; +{ + return(EOPNOTSUPP); +} + +/* end of vfs default ops */ |
