static int msdosfs_deget_dotdot(struct vnode *vp, u_long cluster, int blkoff, struct vnode **rvp) { struct mount *mp; struct msdosfsmount *pmp; struct denode *rdp; int ltype, error; mp = vp->v_mount; pmp = VFSTOMSDOSFS(mp); ltype = VOP_ISLOCKED(vp); KASSERT(ltype == LK_EXCLUSIVE || ltype == LK_SHARED, ("msdosfs_deget_dotdot: vp not locked")); error = vfs_busy(mp, MBF_NOWAIT); if (error != 0) { vfs_ref(mp); VOP_UNLOCK(vp, 0); error = vfs_busy(mp, 0); vn_lock(vp, ltype | LK_RETRY); vfs_rel(mp); if (error != 0) return (ENOENT); if (vp->v_iflag & VI_DOOMED) { vfs_unbusy(mp); return (ENOENT); } } VOP_UNLOCK(vp, 0); error = deget(pmp, cluster, blkoff, &rdp); vfs_unbusy(mp); if (error == 0) *rvp = DETOV(rdp); if (*rvp != vp) vn_lock(vp, ltype | LK_RETRY); if (vp->v_iflag & VI_DOOMED) { if (error == 0) { if (*rvp == vp) vunref(*rvp); else vput(*rvp); } error = ENOENT; } return (error); }
/* * Q_QUOTAON - set up a quota file for a particular filesystem. */ int quotaon(struct thread *td, struct mount *mp, int type, void *fname) { struct ufsmount *ump; struct vnode *vp, **vpp; struct vnode *mvp; struct dquot *dq; int error, flags; struct nameidata nd; error = priv_check(td, PRIV_UFS_QUOTAON); if (error != 0) { vfs_unbusy(mp); return (error); } if ((mp->mnt_flag & MNT_RDONLY) != 0) { vfs_unbusy(mp); return (EROFS); } ump = VFSTOUFS(mp); dq = NODQUOT; NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, fname, td); flags = FREAD | FWRITE; vfs_ref(mp); vfs_unbusy(mp); error = vn_open(&nd, &flags, 0, NULL); if (error != 0) { vfs_rel(mp); return (error); } NDFREE(&nd, NDF_ONLY_PNBUF); vp = nd.ni_vp; error = vfs_busy(mp, MBF_NOWAIT); vfs_rel(mp); if (error == 0) { if (vp->v_type != VREG) { error = EACCES; vfs_unbusy(mp); } } if (error != 0) { VOP_UNLOCK(vp, 0); (void) vn_close(vp, FREAD|FWRITE, td->td_ucred, td); return (error); } UFS_LOCK(ump); if ((ump->um_qflags[type] & (QTF_OPENING|QTF_CLOSING)) != 0) { UFS_UNLOCK(ump); VOP_UNLOCK(vp, 0); (void) vn_close(vp, FREAD|FWRITE, td->td_ucred, td); vfs_unbusy(mp); return (EALREADY); } ump->um_qflags[type] |= QTF_OPENING|QTF_CLOSING; UFS_UNLOCK(ump); if ((error = dqopen(vp, ump, type)) != 0) { VOP_UNLOCK(vp, 0); UFS_LOCK(ump); ump->um_qflags[type] &= ~(QTF_OPENING|QTF_CLOSING); UFS_UNLOCK(ump); (void) vn_close(vp, FREAD|FWRITE, td->td_ucred, td); vfs_unbusy(mp); return (error); } VOP_UNLOCK(vp, 0); MNT_ILOCK(mp); mp->mnt_flag |= MNT_QUOTA; MNT_IUNLOCK(mp); vpp = &ump->um_quotas[type]; if (*vpp != vp) quotaoff1(td, mp, type); /* * When the directory vnode containing the quota file is * inactivated, due to the shared lookup of the quota file * vput()ing the dvp, the qsyncvp() call for the containing * directory would try to acquire the quota lock exclusive. * At the same time, lookup already locked the quota vnode * shared. Mark the quota vnode lock as allowing recursion * and automatically converting shared locks to exclusive. * * Also mark quota vnode as system. */ vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); vp->v_vflag |= VV_SYSTEM; VN_LOCK_AREC(vp); VN_LOCK_DSHARE(vp); VOP_UNLOCK(vp, 0); *vpp = vp; /* * Save the credential of the process that turned on quotas. * Set up the time limits for this quota. */ ump->um_cred[type] = crhold(td->td_ucred); ump->um_btime[type] = MAX_DQ_TIME; ump->um_itime[type] = MAX_IQ_TIME; if (dqget(NULLVP, 0, ump, type, &dq) == 0) { if (dq->dq_btime > 0) ump->um_btime[type] = dq->dq_btime; if (dq->dq_itime > 0) ump->um_itime[type] = dq->dq_itime; dqrele(NULLVP, dq); } /* * Allow the getdq from getinoquota below to read the quota * from file. */ UFS_LOCK(ump); ump->um_qflags[type] &= ~QTF_CLOSING; UFS_UNLOCK(ump); /* * Search vnodes associated with this mount point, * adding references to quota file being opened. * NB: only need to add dquot's for inodes being modified. */ again: MNT_VNODE_FOREACH_ALL(vp, mp, mvp) { if (vget(vp, LK_EXCLUSIVE | LK_INTERLOCK, td)) { MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); goto again; } if (vp->v_type == VNON || vp->v_writecount == 0) { VOP_UNLOCK(vp, 0); vrele(vp); continue; } error = getinoquota(VTOI(vp)); VOP_UNLOCK(vp, 0); vrele(vp); if (error) { MNT_VNODE_FOREACH_ALL_ABORT(mp, mvp); break; } } if (error) quotaoff_inchange(td, mp, type); UFS_LOCK(ump); ump->um_qflags[type] &= ~QTF_OPENING; KASSERT((ump->um_qflags[type] & QTF_CLOSING) == 0, ("quotaon: leaking flags")); UFS_UNLOCK(ump); vfs_unbusy(mp); return (error); }
/* * The system call that results in changing the rootfs. */ static int kern_reroot(void) { struct vnode *oldrootvnode, *vp; struct mount *mp, *devmp; int error; if (curproc != initproc) return (EPERM); /* * Mark the filesystem containing currently-running executable * (the temporary copy of init(8)) busy. */ vp = curproc->p_textvp; error = vn_lock(vp, LK_SHARED); if (error != 0) return (error); mp = vp->v_mount; error = vfs_busy(mp, MBF_NOWAIT); if (error != 0) { vfs_ref(mp); VOP_UNLOCK(vp, 0); error = vfs_busy(mp, 0); vn_lock(vp, LK_SHARED | LK_RETRY); vfs_rel(mp); if (error != 0) { VOP_UNLOCK(vp, 0); return (ENOENT); } if (vp->v_iflag & VI_DOOMED) { VOP_UNLOCK(vp, 0); vfs_unbusy(mp); return (ENOENT); } } VOP_UNLOCK(vp, 0); /* * Remove the filesystem containing currently-running executable * from the mount list, to prevent it from being unmounted * by vfs_unmountall(), and to avoid confusing vfs_mountroot(). * * Also preserve /dev - forcibly unmounting it could cause driver * reinitialization. */ vfs_ref(rootdevmp); devmp = rootdevmp; rootdevmp = NULL; mtx_lock(&mountlist_mtx); TAILQ_REMOVE(&mountlist, mp, mnt_list); TAILQ_REMOVE(&mountlist, devmp, mnt_list); mtx_unlock(&mountlist_mtx); oldrootvnode = rootvnode; /* * Unmount everything except for the two filesystems preserved above. */ vfs_unmountall(); /* * Add /dev back; vfs_mountroot() will move it into its new place. */ mtx_lock(&mountlist_mtx); TAILQ_INSERT_HEAD(&mountlist, devmp, mnt_list); mtx_unlock(&mountlist_mtx); rootdevmp = devmp; vfs_rel(rootdevmp); /* * Mount the new rootfs. */ vfs_mountroot(); /* * Update all references to the old rootvnode. */ mountcheckdirs(oldrootvnode, rootvnode); /* * Add the temporary filesystem back and unbusy it. */ mtx_lock(&mountlist_mtx); TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list); mtx_unlock(&mountlist_mtx); vfs_unbusy(mp); return (0); }
/* struct vnop_lookup_args { struct vnodeop_desc *a_desc; struct vnode *a_dvp; struct vnode **a_vpp; struct componentname *a_cnp; }; */ int fuse_vnop_lookup(struct vop_lookup_args *ap) { struct vnode *dvp = ap->a_dvp; struct vnode **vpp = ap->a_vpp; struct componentname *cnp = ap->a_cnp; struct thread *td = cnp->cn_thread; struct ucred *cred = cnp->cn_cred; int nameiop = cnp->cn_nameiop; int flags = cnp->cn_flags; int wantparent = flags & (LOCKPARENT | WANTPARENT); int islastcn = flags & ISLASTCN; struct mount *mp = vnode_mount(dvp); int err = 0; int lookup_err = 0; struct vnode *vp = NULL; struct fuse_dispatcher fdi; enum fuse_opcode op; uint64_t nid; struct fuse_access_param facp; FS_DEBUG2G("parent_inode=%ju - %*s\n", (uintmax_t)VTOI(dvp), (int)cnp->cn_namelen, cnp->cn_nameptr); if (fuse_isdeadfs(dvp)) { *vpp = NULL; return ENXIO; } if (!vnode_isdir(dvp)) { return ENOTDIR; } if (islastcn && vfs_isrdonly(mp) && (nameiop != LOOKUP)) { return EROFS; } /* * We do access check prior to doing anything else only in the case * when we are at fs root (we'd like to say, "we are at the first * component", but that's not exactly the same... nevermind). * See further comments at further access checks. */ bzero(&facp, sizeof(facp)); if (vnode_isvroot(dvp)) { /* early permission check hack */ if ((err = fuse_internal_access(dvp, VEXEC, &facp, td, cred))) { return err; } } if (flags & ISDOTDOT) { nid = VTOFUD(dvp)->parent_nid; if (nid == 0) { return ENOENT; } fdisp_init(&fdi, 0); op = FUSE_GETATTR; goto calldaemon; } else if (cnp->cn_namelen == 1 && *(cnp->cn_nameptr) == '.') { nid = VTOI(dvp); fdisp_init(&fdi, 0); op = FUSE_GETATTR; goto calldaemon; } else if (fuse_lookup_cache_enable) { err = cache_lookup(dvp, vpp, cnp, NULL, NULL); switch (err) { case -1: /* positive match */ atomic_add_acq_long(&fuse_lookup_cache_hits, 1); return 0; case 0: /* no match in cache */ atomic_add_acq_long(&fuse_lookup_cache_misses, 1); break; case ENOENT: /* negative match */ /* fall through */ default: return err; } } nid = VTOI(dvp); fdisp_init(&fdi, cnp->cn_namelen + 1); op = FUSE_LOOKUP; calldaemon: fdisp_make(&fdi, op, mp, nid, td, cred); if (op == FUSE_LOOKUP) { memcpy(fdi.indata, cnp->cn_nameptr, cnp->cn_namelen); ((char *)fdi.indata)[cnp->cn_namelen] = '\0'; } lookup_err = fdisp_wait_answ(&fdi); if ((op == FUSE_LOOKUP) && !lookup_err) { /* lookup call succeeded */ nid = ((struct fuse_entry_out *)fdi.answ)->nodeid; if (!nid) { /* * zero nodeid is the same as "not found", * but it's also cacheable (which we keep * keep on doing not as of writing this) */ lookup_err = ENOENT; } else if (nid == FUSE_ROOT_ID) { lookup_err = EINVAL; } } if (lookup_err && (!fdi.answ_stat || lookup_err != ENOENT || op != FUSE_LOOKUP)) { fdisp_destroy(&fdi); return lookup_err; } /* lookup_err, if non-zero, must be ENOENT at this point */ if (lookup_err) { if ((nameiop == CREATE || nameiop == RENAME) && islastcn /* && directory dvp has not been removed */ ) { if (vfs_isrdonly(mp)) { err = EROFS; goto out; } #if 0 /* THINK_ABOUT_THIS */ if ((err = fuse_internal_access(dvp, VWRITE, cred, td, &facp))) { goto out; } #endif /* * Possibly record the position of a slot in the * directory large enough for the new component name. * This can be recorded in the vnode private data for * dvp. Set the SAVENAME flag to hold onto the * pathname for use later in VOP_CREATE or VOP_RENAME. */ cnp->cn_flags |= SAVENAME; err = EJUSTRETURN; goto out; } /* Consider inserting name into cache. */ /* * No we can't use negative caching, as the fs * changes are out of our control. * False positives' falseness turns out just as things * go by, but false negatives' falseness doesn't. * (and aiding the caching mechanism with extra control * mechanisms comes quite close to beating the whole purpose * caching...) */ #if 0 if ((cnp->cn_flags & MAKEENTRY) && nameiop != CREATE) { FS_DEBUG("inserting NULL into cache\n"); cache_enter(dvp, NULL, cnp); } #endif err = ENOENT; goto out; } else { /* !lookup_err */ struct fuse_entry_out *feo = NULL; struct fuse_attr *fattr = NULL; if (op == FUSE_GETATTR) { fattr = &((struct fuse_attr_out *)fdi.answ)->attr; } else { feo = (struct fuse_entry_out *)fdi.answ; fattr = &(feo->attr); } /* * If deleting, and at end of pathname, return parameters * which can be used to remove file. If the wantparent flag * isn't set, we return only the directory, otherwise we go on * and lock the inode, being careful with ".". */ if (nameiop == DELETE && islastcn) { /* * Check for write access on directory. */ facp.xuid = fattr->uid; facp.facc_flags |= FACCESS_STICKY; err = fuse_internal_access(dvp, VWRITE, &facp, td, cred); facp.facc_flags &= ~FACCESS_XQUERIES; if (err) { goto out; } if (nid == VTOI(dvp)) { vref(dvp); *vpp = dvp; } else { err = fuse_vnode_get(dvp->v_mount, nid, dvp, &vp, cnp, IFTOVT(fattr->mode)); if (err) goto out; *vpp = vp; } /* * Save the name for use in VOP_RMDIR and VOP_REMOVE * later. */ cnp->cn_flags |= SAVENAME; goto out; } /* * If rewriting (RENAME), return the inode and the * information required to rewrite the present directory * Must get inode of directory entry to verify it's a * regular file, or empty directory. */ if (nameiop == RENAME && wantparent && islastcn) { #if 0 /* THINK_ABOUT_THIS */ if ((err = fuse_internal_access(dvp, VWRITE, cred, td, &facp))) { goto out; } #endif /* * Check for "." */ if (nid == VTOI(dvp)) { err = EISDIR; goto out; } err = fuse_vnode_get(vnode_mount(dvp), nid, dvp, &vp, cnp, IFTOVT(fattr->mode)); if (err) { goto out; } *vpp = vp; /* * Save the name for use in VOP_RENAME later. */ cnp->cn_flags |= SAVENAME; goto out; } if (flags & ISDOTDOT) { struct mount *mp; int ltype; /* * Expanded copy of vn_vget_ino() so that * fuse_vnode_get() can be used. */ mp = dvp->v_mount; ltype = VOP_ISLOCKED(dvp); err = vfs_busy(mp, MBF_NOWAIT); if (err != 0) { vfs_ref(mp); VOP_UNLOCK(dvp, 0); err = vfs_busy(mp, 0); vn_lock(dvp, ltype | LK_RETRY); vfs_rel(mp); if (err) goto out; if ((dvp->v_iflag & VI_DOOMED) != 0) { err = ENOENT; vfs_unbusy(mp); goto out; } } VOP_UNLOCK(dvp, 0); err = fuse_vnode_get(vnode_mount(dvp), nid, NULL, &vp, cnp, IFTOVT(fattr->mode)); vfs_unbusy(mp); vn_lock(dvp, ltype | LK_RETRY); if ((dvp->v_iflag & VI_DOOMED) != 0) { if (err == 0) vput(vp); err = ENOENT; } if (err) goto out; *vpp = vp; } else if (nid == VTOI(dvp)) { vref(dvp); *vpp = dvp; } else { err = fuse_vnode_get(vnode_mount(dvp), nid, dvp, &vp, cnp, IFTOVT(fattr->mode)); if (err) { goto out; } fuse_vnode_setparent(vp, dvp); *vpp = vp; } if (op == FUSE_GETATTR) { cache_attrs(*vpp, (struct fuse_attr_out *)fdi.answ); } else { cache_attrs(*vpp, (struct fuse_entry_out *)fdi.answ); } /* Insert name into cache if appropriate. */ /* * Nooo, caching is evil. With caching, we can't avoid stale * information taking over the playground (cached info is not * just positive/negative, it does have qualitative aspects, * too). And a (VOP/FUSE)_GETATTR is always thrown anyway, when * walking down along cached path components, and that's not * any cheaper than FUSE_LOOKUP. This might change with * implementing kernel side attr caching, but... In Linux, * lookup results are not cached, and the daemon is bombarded * with FUSE_LOOKUPS on and on. This shows that by design, the * daemon is expected to handle frequent lookup queries * efficiently, do its caching in userspace, and so on. * * So just leave the name cache alone. */ /* * Well, now I know, Linux caches lookups, but with a * timeout... So it's the same thing as attribute caching: * we can deal with it when implement timeouts. */ #if 0 if (cnp->cn_flags & MAKEENTRY) { cache_enter(dvp, *vpp, cnp); } #endif } out: if (!lookup_err) { /* No lookup error; need to clean up. */ if (err) { /* Found inode; exit with no vnode. */ if (op == FUSE_LOOKUP) { fuse_internal_forget_send(vnode_mount(dvp), td, cred, nid, 1); } fdisp_destroy(&fdi); return err; } else { #ifndef NO_EARLY_PERM_CHECK_HACK if (!islastcn) { /* * We have the attributes of the next item * *now*, and it's a fact, and we do not * have to do extra work for it (ie, beg the * daemon), and it neither depends on such * accidental things like attr caching. So * the big idea: check credentials *now*, * not at the beginning of the next call to * lookup. * * The first item of the lookup chain (fs root) * won't be checked then here, of course, as * its never "the next". But go and see that * the root is taken care about at the very * beginning of this function. * * Now, given we want to do the access check * this way, one might ask: so then why not * do the access check just after fetching * the inode and its attributes from the * daemon? Why bother with producing the * corresponding vnode at all if something * is not OK? We know what's the deal as * soon as we get those attrs... There is * one bit of info though not given us by * the daemon: whether his response is * authorative or not... His response should * be ignored if something is mounted over * the dir in question. But that can be * known only by having the vnode... */ int tmpvtype = vnode_vtype(*vpp); bzero(&facp, sizeof(facp)); /*the early perm check hack */ facp.facc_flags |= FACCESS_VA_VALID; if ((tmpvtype != VDIR) && (tmpvtype != VLNK)) { err = ENOTDIR; } if (!err && !vnode_mountedhere(*vpp)) { err = fuse_internal_access(*vpp, VEXEC, &facp, td, cred); } if (err) { if (tmpvtype == VLNK) FS_DEBUG("weird, permission error with a symlink?\n"); vput(*vpp); *vpp = NULL; } } #endif } } fdisp_destroy(&fdi); return err; }