/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2008 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #pragma ident "%Z%%M% %I% %E% SMI" /* * This is the device filesystem. * * It is a combination of a namer to drive autoconfiguration, * plus the access methods for the device drivers of the system. * * The prototype is fairly dependent on specfs for the latter part * of its implementation, though a final version would integrate the two. */ #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 /* * devfs vfs operations. */ static int devfs_mount(struct vfs *, struct vnode *, struct mounta *, struct cred *); static int devfs_unmount(struct vfs *, int, struct cred *); static int devfs_root(struct vfs *, struct vnode **); static int devfs_statvfs(struct vfs *, struct statvfs64 *); static int devfs_mountroot(struct vfs *, enum whymountroot); static int devfsinit(int, char *); static vfsdef_t devfs_vfssw = { VFSDEF_VERSION, "devfs", /* type name string */ devfsinit, /* init routine */ 0, /* flags */ NULL /* mount options table prototype */ }; static kmutex_t devfs_lock; /* protects global data */ static int devfstype; /* fstype */ static dev_t devfsdev; /* the fictious 'device' we live on */ static struct devfs_data *devfs_mntinfo; /* linked list of instances */ /* * Module linkage information */ static struct modlfs modlfs = { &mod_fsops, "devices filesystem %I%", &devfs_vfssw }; static struct modlinkage modlinkage = { MODREV_1, (void *)&modlfs, NULL }; int _init(void) { int e; mutex_init(&devfs_lock, "devfs lock", MUTEX_DEFAULT, NULL); dv_node_cache_init(); if ((e = mod_install(&modlinkage)) != 0) { dv_node_cache_fini(); mutex_destroy(&devfs_lock); return (e); } dcmn_err(("devfs loaded\n")); return (0); } int _fini(void) { return (EBUSY); } int _info(struct modinfo *modinfop) { return (mod_info(&modlinkage, modinfop)); } /*ARGSUSED1*/ static int devfsinit(int fstype, char *name) { static const fs_operation_def_t devfs_vfsops_template[] = { VFSNAME_MOUNT, { .vfs_mount = devfs_mount }, VFSNAME_UNMOUNT, { .vfs_unmount = devfs_unmount }, VFSNAME_ROOT, { .vfs_root = devfs_root }, VFSNAME_STATVFS, { .vfs_statvfs = devfs_statvfs }, VFSNAME_SYNC, { .vfs_sync = fs_sync }, VFSNAME_MOUNTROOT, { .vfs_mountroot = devfs_mountroot }, NULL, NULL }; int error; int dev; extern major_t getudev(void); /* gack - what a function */ devfstype = fstype; /* * Associate VFS ops vector with this fstype */ error = vfs_setfsops(fstype, devfs_vfsops_template, NULL); if (error != 0) { cmn_err(CE_WARN, "devfsinit: bad vfs ops template"); return (error); } error = vn_make_ops("dev fs", dv_vnodeops_template, &dv_vnodeops); if (error != 0) { (void) vfs_freevfsops_by_type(fstype); cmn_err(CE_WARN, "devfsinit: bad vnode ops template"); return (error); } /* * Invent a dev_t (sigh). */ if ((dev = getudev()) == DDI_MAJOR_T_NONE) { cmn_err(CE_NOTE, "%s: can't get unique dev", devfs_vfssw.name); dev = 0; } devfsdev = makedevice(dev, 0); return (0); } /* * The name of the mount point and the name of the attribute * filesystem are passed down from userland for now. */ static int devfs_mount(struct vfs *vfsp, struct vnode *mvp, struct mounta *uap, struct cred *cr) { struct devfs_data *devfs_data; struct vnode *avp; struct dv_node *dv; struct vattr va; dcmn_err(("devfs_mount\n")); if (secpolicy_fs_mount(cr, mvp, vfsp) != 0) return (EPERM); /* * check that the mount point is sane */ if (mvp->v_type != VDIR) return (ENOTDIR); ASSERT(uap->flags & MS_SYSSPACE); /* * Devfs can only be mounted from kernel during boot. * avp is the existing /devices, the same as the mount point. */ avp = mvp; /* * Create and initialize the vfs-private data. * This includes a hand-crafted root vnode (we build * this here mostly so that traverse() doesn't sleep * in VFS_ROOT()). */ mutex_enter(&devfs_lock); ASSERT(devfs_mntinfo == NULL); dv = dv_mkroot(vfsp, devfsdev); dv->dv_attrvp = avp; /* attribute root vp */ ASSERT(dv == dv->dv_dotdot); devfs_data = kmem_zalloc(sizeof (struct devfs_data), KM_SLEEP); devfs_data->devfs_vfsp = vfsp; devfs_data->devfs_root = dv; vfsp->vfs_data = (caddr_t)devfs_data; vfsp->vfs_fstype = devfstype; vfsp->vfs_dev = devfsdev; vfsp->vfs_bsize = DEV_BSIZE; vfsp->vfs_mtime = ddi_get_time(); vfs_make_fsid(&vfsp->vfs_fsid, vfsp->vfs_dev, devfstype); /* We're there. */ devfs_mntinfo = devfs_data; mutex_exit(&devfs_lock); va.va_mask = AT_ATIME|AT_MTIME; gethrestime(&va.va_atime); gethrestime(&va.va_mtime); (void) VOP_SETATTR(DVTOV(dv), &va, 0, cr, NULL); return (0); } /* * We never unmount devfs in a real production system. */ /*ARGSUSED*/ static int devfs_unmount(struct vfs *vfsp, int flag, struct cred *cr) { return (EBUSY); } /* * return root vnode for given vfs */ static int devfs_root(struct vfs *vfsp, struct vnode **vpp) { dcmn_err(("devfs_root\n")); *vpp = DVTOV(VFSTODVFS(vfsp)->devfs_root); VN_HOLD(*vpp); return (0); } /* * return 'generic superblock' information to userland. * * not much that we can usefully admit to here */ static int devfs_statvfs(struct vfs *vfsp, struct statvfs64 *sbp) { extern kmem_cache_t *dv_node_cache; dev32_t d32; dcmn_err(("devfs_statvfs\n")); bzero(sbp, sizeof (*sbp)); sbp->f_frsize = sbp->f_bsize = vfsp->vfs_bsize; /* * We could compute the number of devfsnodes here .. but since * it's dynamic anyway, it's not clear how useful this is. */ sbp->f_files = kmem_cache_stat(dv_node_cache, "alloc"); /* no illusions that free/avail files is relevant to devfs */ sbp->f_ffree = 0; sbp->f_favail = 0; /* no illusions that blocks are relevant to devfs */ sbp->f_bfree = 0; sbp->f_bavail = 0; sbp->f_blocks = 0; (void) cmpldev(&d32, vfsp->vfs_dev); sbp->f_fsid = d32; (void) strcpy(sbp->f_basetype, vfssw[devfstype].vsw_name); sbp->f_flag = vf_to_stf(vfsp->vfs_flag); sbp->f_namemax = MAXNAMELEN - 1; (void) strcpy(sbp->f_fstr, "devices"); return (0); } /* * devfs always mount after root is mounted, so this should never * be invoked. */ /*ARGSUSED*/ static int devfs_mountroot(struct vfs *vfsp, enum whymountroot why) { dcmn_err(("devfs_mountroot\n")); return (EINVAL); } struct dv_node * devfs_dip_to_dvnode(dev_info_t *dip) { char *dirpath; struct vnode *dirvp; ASSERT(dip != NULL); /* no-op if devfs not mounted yet */ if (devfs_mntinfo == NULL) return (NULL); /* * The lookupname below only looks up cached dv_nodes * because devfs_clean_key is set in thread specific data. */ dirpath = kmem_alloc(MAXPATHLEN, KM_SLEEP); (void) ddi_pathname(dip, dirpath); if (devfs_lookupname(dirpath, NULLVPP, &dirvp)) { dcmn_err(("directory %s not found\n", dirpath)); kmem_free(dirpath, MAXPATHLEN); return (NULL); } kmem_free(dirpath, MAXPATHLEN); return (VTODV(dirvp)); } /* * If DV_CLEAN_FORCE devfs_clean is issued with a dip that is not the root * and not a vHCI we also need to clean any vHCI branches because they * may contain pHCI nodes. A detach_node() of a pHCI will fail if its * mdi_devi_offline() fails, and the mdi_devi_offline() of the last * pHCI will fail unless an ndi_devi_offline() of the Client nodes under * the vHCI is successful - which requires a clean vHCI branch to removed * the devi_refs associated with devfs vnodes. */ static int devfs_clean_vhci(dev_info_t *dip, void *args) { struct dv_node *dvp; uint_t flags = (uint_t)(uintptr_t)args; (void) tsd_set(devfs_clean_key, (void *)1); dvp = devfs_dip_to_dvnode(dip); if (dvp) { (void) dv_cleandir(dvp, NULL, flags); VN_RELE(DVTOV(dvp)); } (void) tsd_set(devfs_clean_key, NULL); return (DDI_WALK_CONTINUE); } /* * devfs_clean() * * Destroy unreferenced dv_node's and detach devices. * * devfs_clean will try its best to clean up unused nodes. It is * no longer valid to assume that just because devfs_clean fails, * the device is not removable. This is because device contracts * can result in userland processes releasing a device during the * device offline process in the kernel. Thus it is no longer * correct to fail an offline just because devfs_clean finds * referenced dv_nodes. To enforce this, devfs_clean() always * returns success i.e. 0. * * devfs_clean() may return before removing all possible nodes if * we cannot acquire locks in areas of the code where potential for * deadlock exists (see comments in dv_find() and dv_cleandir() for * examples of this). * * devfs caches unreferenced dv_node to speed by the performance * of ls, find, etc. devfs_clean() is invoked to cleanup cached * dv_nodes to reclaim memory as well as to facilitate device * removal (dv_node reference devinfo nodes, which prevents driver * detach). * * If a shell parks in a /devices directory, the dv_node will be * held, preventing the corresponding device to be detached. * This would be a denial of service against DR. To prevent this, * DR code calls devfs_clean() with the DV_CLEAN_FORCE flag. * The dv_cleandir() implementation does the right thing to ensure * successful DR. */ int devfs_clean(dev_info_t *dip, char *devnm, uint_t flags) { struct dv_node *dvp; dcmn_err(("devfs_unconfigure: dip = 0x%p, flags = 0x%x", (void *)dip, flags)); /* avoid recursion back into the device tree */ (void) tsd_set(devfs_clean_key, (void *)1); dvp = devfs_dip_to_dvnode(dip); if (dvp == NULL) { (void) tsd_set(devfs_clean_key, NULL); return (0); } (void) dv_cleandir(dvp, devnm, flags); (void) tsd_set(devfs_clean_key, NULL); VN_RELE(DVTOV(dvp)); /* * If we are doing a DV_CLEAN_FORCE, and we did not start at the * root, and we did not start at a vHCI node then clean vHCI * branches too. Failure to clean vHCI branch does not cause EBUSY. * * Also, to accommodate nexus callers that clean 'self' to DR 'child' * (like pcihp) we clean vHCIs even when dv_cleandir() of dip branch * above fails - this prevents a busy DR 'child' sibling from causing * the DR of 'child' to fail because a vHCI branch was not cleaned. */ if ((flags & DV_CLEAN_FORCE) && (dip != ddi_root_node()) && (mdi_component_is_vhci(dip, NULL) != MDI_SUCCESS)) { /* * NOTE: for backport the following is recommended * (void) devfs_clean_vhci(scsi_vhci_dip, * (void *)(uintptr_t)flags); */ mdi_walk_vhcis(devfs_clean_vhci, (void *)(uintptr_t)flags); } return (0); } /* * lookup a devfs relative pathname, returning held vnodes for the final * component and the containing directory (if requested). * * NOTE: We can't use lookupname because this would use the current * processes credentials (CRED) in the call lookuppnvp instead * of kcred. It also does not give you the flexibility so * specify the directory to start the resolution in (devicesdir). */ int devfs_lookupname( char *pathname, /* user pathname */ vnode_t **dirvpp, /* ret for ptr to parent dir vnode */ vnode_t **compvpp) /* ret for ptr to component vnode */ { struct pathname pn; int error; ASSERT(devicesdir); /* devfs must be initialized */ ASSERT(pathname); /* must have some path */ if (error = pn_get(pathname, UIO_SYSSPACE, &pn)) return (error); /* make the path relative to /devices. */ pn_skipslash(&pn); if (pn_pathleft(&pn) == 0) { /* all we had was "\0" or "/" (which skipslash skiped) */ if (dirvpp) *dirvpp = NULL; if (compvpp) { VN_HOLD(devicesdir); *compvpp = devicesdir; } } else { /* * Use devfs lookup to resolve pathname to the vnode for * the device via relative lookup in devfs. Extra holds for * using devicesdir as directory we are searching and for * being our root without being == rootdir. */ VN_HOLD(devicesdir); VN_HOLD(devicesdir); error = lookuppnvp(&pn, NULL, FOLLOW, dirvpp, compvpp, devicesdir, devicesdir, kcred); } pn_free(&pn); return (error); } /* * Given a devfs path (without the /devices prefix), walk * the dv_node sub-tree rooted at the path. */ int devfs_walk( char *path, void (*callback)(struct dv_node *, void *), void *arg) { char *dirpath, *devnm; struct vnode *dirvp; ASSERT(path && callback); if (*path != '/' || devfs_mntinfo == NULL) return (ENXIO); dcmn_err(("devfs_walk: path = %s", path)); dirpath = kmem_alloc(MAXPATHLEN, KM_SLEEP); (void) snprintf(dirpath, MAXPATHLEN, "/devices%s", path); devnm = strrchr(dirpath, '/'); ASSERT(devnm); *devnm++ = '\0'; if (lookupname(dirpath, UIO_SYSSPACE, 0, NULL, &dirvp)) { dcmn_err(("directory %s not found\n", dirpath)); kmem_free(dirpath, MAXPATHLEN); return (ENXIO); } /* * if path == "/", visit the root dv_node */ if (*devnm == '\0') { callback(VTODV(dirvp), arg); devnm = NULL; } dv_walk(VTODV(dirvp), devnm, callback, arg); VN_RELE(dirvp); kmem_free(dirpath, MAXPATHLEN); return (0); } int devfs_devpolicy(vnode_t *vp, devplcy_t **dpp) { struct vnode *rvp; struct dv_node *dvp; int rval = -1; /* fail if devfs not mounted yet */ if (devfs_mntinfo == NULL) return (rval); if (VOP_REALVP(vp, &rvp, NULL) == 0 && vn_matchops(rvp, dv_vnodeops)) { dvp = VTODV(rvp); rw_enter(&dvp->dv_contents, RW_READER); if (dvp->dv_priv) { dphold(dvp->dv_priv); *dpp = dvp->dv_priv; rval = 0; } rw_exit(&dvp->dv_contents); } return (rval); }