/*- * 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. * 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. * * @(#)vfs_init.c 8.3 (Berkeley) 1/4/94 */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include static int vfs_register(struct vfsconf *); static int vfs_unregister(struct vfsconf *); MALLOC_DEFINE(M_VNODE, "vnodes", "Dynamically allocated vnodes"); /* * The highest defined VFS number. */ int maxvfsconf = VFS_GENERIC + 1; /* * Single-linked list of configured VFSes. * New entries are added/deleted by vfs_register()/vfs_unregister() */ struct vfsconfhead vfsconf = TAILQ_HEAD_INITIALIZER(vfsconf); struct sx vfsconf_sx; SX_SYSINIT(vfsconf, &vfsconf_sx, "vfsconf"); /* * Loader.conf variable vfs.typenumhash enables setting vfc_typenum using a hash * calculation on vfc_name, so that it doesn't change when file systems are * loaded in a different order. This will avoid the NFS server file handles from * changing for file systems that use vfc_typenum in their fsid. */ static int vfs_typenumhash = 1; TUNABLE_INT("vfs.typenumhash", &vfs_typenumhash); SYSCTL_INT(_vfs, OID_AUTO, typenumhash, CTLFLAG_RDTUN, &vfs_typenumhash, 0, "Set vfc_typenum using a hash calculation on vfc_name, so that it does not" "change when file systems are loaded in a different order."); /* * A Zen vnode attribute structure. * * Initialized when the first filesystem registers by vfs_register(). */ struct vattr va_null; /* * vfs_init.c * * Allocate and fill in operations vectors. * * An undocumented feature of this approach to defining operations is that * there can be multiple entries in vfs_opv_descs for the same operations * vector. This allows third parties to extend the set of operations * supported by another layer in a binary compatibile way. For example, * assume that NFS needed to be modified to support Ficus. NFS has an entry * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions) * listing those new operations Ficus adds to NFS, all without modifying the * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but * that is a(whole)nother story.) This is a feature. */ /* * Routines having to do with the management of the vnode table. */ static struct vfsconf * vfs_byname_locked(const char *name) { struct vfsconf *vfsp; sx_assert(&vfsconf_sx, SA_LOCKED); if (!strcmp(name, "ffs")) name = "ufs"; TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) { if (!strcmp(name, vfsp->vfc_name)) return (vfsp); } return (NULL); } struct vfsconf * vfs_byname(const char *name) { struct vfsconf *vfsp; vfsconf_slock(); vfsp = vfs_byname_locked(name); vfsconf_sunlock(); return (vfsp); } struct vfsconf * vfs_byname_kld(const char *fstype, struct thread *td, int *error) { struct vfsconf *vfsp; int fileid, loaded; vfsp = vfs_byname(fstype); if (vfsp != NULL) return (vfsp); /* Try to load the respective module. */ *error = kern_kldload(td, fstype, &fileid); loaded = (*error == 0); if (*error == EEXIST) *error = 0; if (*error) return (NULL); /* Look up again to see if the VFS was loaded. */ vfsp = vfs_byname(fstype); if (vfsp == NULL) { if (loaded) (void)kern_kldunload(td, fileid, LINKER_UNLOAD_FORCE); *error = ENODEV; return (NULL); } return (vfsp); } /* Register a new filesystem type in the global table */ static int vfs_register(struct vfsconf *vfc) { struct sysctl_oid *oidp; struct vfsops *vfsops; static int once; struct vfsconf *tvfc; uint32_t hashval; int secondpass; if (!once) { vattr_null(&va_null); once = 1; } if (vfc->vfc_version != VFS_VERSION) { printf("ERROR: filesystem %s, unsupported ABI version %x\n", vfc->vfc_name, vfc->vfc_version); return (EINVAL); } vfsconf_lock(); if (vfs_byname_locked(vfc->vfc_name) != NULL) { vfsconf_unlock(); return (EEXIST); } if (vfs_typenumhash != 0) { /* * Calculate a hash on vfc_name to use for vfc_typenum. Unless * all of 1<->255 are assigned, it is limited to 8bits since * that is what ZFS uses from vfc_typenum and is also the * preferred range for vfs_getnewfsid(). */ hashval = fnv_32_str(vfc->vfc_name, FNV1_32_INIT); hashval &= 0xff; secondpass = 0; do { /* Look for and fix any collision. */ TAILQ_FOREACH(tvfc, &vfsconf, vfc_list) { if (hashval == tvfc->vfc_typenum) { if (hashval == 255 && secondpass == 0) { hashval = 1; secondpass = 1; } else hashval++; break; } } } while (tvfc != NULL); vfc->vfc_typenum = hashval; if (vfc->vfc_typenum >= maxvfsconf) maxvfsconf = vfc->vfc_typenum + 1; } else vfc->vfc_typenum = maxvfsconf++; TAILQ_INSERT_TAIL(&vfsconf, vfc, vfc_list); /* * Initialise unused ``struct vfsops'' fields, to use * the vfs_std*() functions. Note, we need the mount * and unmount operations, at the least. The check * for vfsops available is just a debugging aid. */ KASSERT(vfc->vfc_vfsops != NULL, ("Filesystem %s has no vfsops", vfc->vfc_name)); /* * Check the mount and unmount operations. */ vfsops = vfc->vfc_vfsops; KASSERT(vfsops->vfs_mount != NULL, ("Filesystem %s has no mount op", vfc->vfc_name)); KASSERT(vfsops->vfs_unmount != NULL, ("Filesystem %s has no unmount op", vfc->vfc_name)); if (vfsops->vfs_root == NULL) /* return file system's root vnode */ vfsops->vfs_root = vfs_stdroot; if (vfsops->vfs_quotactl == NULL) /* quota control */ vfsops->vfs_quotactl = vfs_stdquotactl; if (vfsops->vfs_statfs == NULL) /* return file system's status */ vfsops->vfs_statfs = vfs_stdstatfs; if (vfsops->vfs_sync == NULL) /* * flush unwritten data (nosync) * file systems can use vfs_stdsync * explicitly by setting it in the * vfsop vector. */ vfsops->vfs_sync = vfs_stdnosync; if (vfsops->vfs_vget == NULL) /* convert an inode number to a vnode */ vfsops->vfs_vget = vfs_stdvget; if (vfsops->vfs_fhtovp == NULL) /* turn an NFS file handle into a vnode */ vfsops->vfs_fhtovp = vfs_stdfhtovp; if (vfsops->vfs_checkexp == NULL) /* check if file system is exported */ vfsops->vfs_checkexp = vfs_stdcheckexp; if (vfsops->vfs_init == NULL) /* file system specific initialisation */ vfsops->vfs_init = vfs_stdinit; if (vfsops->vfs_uninit == NULL) /* file system specific uninitialisation */ vfsops->vfs_uninit = vfs_stduninit; if (vfsops->vfs_extattrctl == NULL) /* extended attribute control */ vfsops->vfs_extattrctl = vfs_stdextattrctl; if (vfsops->vfs_sysctl == NULL) vfsops->vfs_sysctl = vfs_stdsysctl; /* * Call init function for this VFS... */ (*(vfc->vfc_vfsops->vfs_init))(vfc); vfsconf_unlock(); /* * If this filesystem has a sysctl node under vfs * (i.e. vfs.xxfs), then change the oid number of that node to * match the filesystem's type number. This allows user code * which uses the type number to read sysctl variables defined * by the filesystem to continue working. Since the oids are * in a sorted list, we need to make sure the order is * preserved by re-registering the oid after modifying its * number. */ sysctl_lock(); SLIST_FOREACH(oidp, &sysctl__vfs_children, oid_link) { if (strcmp(oidp->oid_name, vfc->vfc_name) == 0) { sysctl_unregister_oid(oidp); oidp->oid_number = vfc->vfc_typenum; sysctl_register_oid(oidp); break; } } sysctl_unlock(); return (0); } /* Remove registration of a filesystem type */ static int vfs_unregister(struct vfsconf *vfc) { struct vfsconf *vfsp; int error, maxtypenum; vfsconf_lock(); vfsp = vfs_byname_locked(vfc->vfc_name); if (vfsp == NULL) { vfsconf_unlock(); return (EINVAL); } if (vfsp->vfc_refcount != 0) { vfsconf_unlock(); return (EBUSY); } if (vfc->vfc_vfsops->vfs_uninit != NULL) { error = (*vfc->vfc_vfsops->vfs_uninit)(vfsp); if (error != 0) { vfsconf_unlock(); return (error); } } TAILQ_REMOVE(&vfsconf, vfsp, vfc_list); maxtypenum = VFS_GENERIC; TAILQ_FOREACH(vfsp, &vfsconf, vfc_list) if (maxtypenum < vfsp->vfc_typenum) maxtypenum = vfsp->vfc_typenum; maxvfsconf = maxtypenum + 1; vfsconf_unlock(); return (0); } /* * Standard kernel module handling code for filesystem modules. * Referenced from VFS_SET(). */ int vfs_modevent(module_t mod, int type, void *data) { struct vfsconf *vfc; int error = 0; vfc = (struct vfsconf *)data; switch (type) { case MOD_LOAD: if (vfc) error = vfs_register(vfc); break; case MOD_UNLOAD: if (vfc) error = vfs_unregister(vfc); break; default: error = EOPNOTSUPP; break; } return (error); }