/* $NetBSD: tmpfs_subr.c,v 1.35 2007/07/09 21:10:50 ad Exp $ */ /*- * Copyright (c) 2005 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Julio M. Merino Vidal, developed as part of Google's Summer of Code * 2005 program. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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. */ /* * Efficient memory file system supporting functions. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include SYSCTL_NODE(_vfs, OID_AUTO, tmpfs, CTLFLAG_RW, 0, "tmpfs file system"); static long tmpfs_pages_reserved = TMPFS_PAGES_MINRESERVED; static int sysctl_mem_reserved(SYSCTL_HANDLER_ARGS) { int error; long pages, bytes; pages = *(long *)arg1; bytes = pages * PAGE_SIZE; error = sysctl_handle_long(oidp, &bytes, 0, req); if (error || !req->newptr) return (error); pages = bytes / PAGE_SIZE; if (pages < TMPFS_PAGES_MINRESERVED) return (EINVAL); *(long *)arg1 = pages; return (0); } SYSCTL_PROC(_vfs_tmpfs, OID_AUTO, memory_reserved, CTLTYPE_LONG|CTLFLAG_RW, &tmpfs_pages_reserved, 0, sysctl_mem_reserved, "L", "Amount of available memory and swap below which tmpfs growth stops"); size_t tmpfs_mem_avail(void) { vm_ooffset_t avail; avail = swap_pager_avail + cnt.v_free_count + cnt.v_cache_count - tmpfs_pages_reserved; if (__predict_false(avail < 0)) avail = 0; return (avail); } size_t tmpfs_pages_used(struct tmpfs_mount *tmp) { const size_t node_size = sizeof(struct tmpfs_node) + sizeof(struct tmpfs_dirent); size_t meta_pages; meta_pages = howmany((uintmax_t)tmp->tm_nodes_inuse * node_size, PAGE_SIZE); return (meta_pages + tmp->tm_pages_used); } static size_t tmpfs_pages_check_avail(struct tmpfs_mount *tmp, size_t req_pages) { if (tmpfs_mem_avail() < req_pages) return (0); if (tmp->tm_pages_max != SIZE_MAX && tmp->tm_pages_max < req_pages + tmpfs_pages_used(tmp)) return (0); return (1); } /* --------------------------------------------------------------------- */ /* * Allocates a new node of type 'type' inside the 'tmp' mount point, with * its owner set to 'uid', its group to 'gid' and its mode set to 'mode', * using the credentials of the process 'p'. * * If the node type is set to 'VDIR', then the parent parameter must point * to the parent directory of the node being created. It may only be NULL * while allocating the root node. * * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter * specifies the device the node represents. * * If the node type is set to 'VLNK', then the parameter target specifies * the file name of the target file for the symbolic link that is being * created. * * Note that new nodes are retrieved from the available list if it has * items or, if it is empty, from the node pool as long as there is enough * space to create them. * * Returns zero on success or an appropriate error code on failure. */ int tmpfs_alloc_node(struct tmpfs_mount *tmp, enum vtype type, uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *parent, char *target, dev_t rdev, struct tmpfs_node **node) { struct tmpfs_node *nnode; /* If the root directory of the 'tmp' file system is not yet * allocated, this must be the request to do it. */ MPASS(IMPLIES(tmp->tm_root == NULL, parent == NULL && type == VDIR)); MPASS(IFF(type == VLNK, target != NULL)); MPASS(IFF(type == VBLK || type == VCHR, rdev != VNOVAL)); if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max) return (ENOSPC); if (tmpfs_pages_check_avail(tmp, 1) == 0) return (ENOSPC); nnode = (struct tmpfs_node *)uma_zalloc_arg( tmp->tm_node_pool, tmp, M_WAITOK); /* Generic initialization. */ nnode->tn_type = type; vfs_timestamp(&nnode->tn_atime); nnode->tn_birthtime = nnode->tn_ctime = nnode->tn_mtime = nnode->tn_atime; nnode->tn_uid = uid; nnode->tn_gid = gid; nnode->tn_mode = mode; nnode->tn_id = alloc_unr(tmp->tm_ino_unr); /* Type-specific initialization. */ switch (nnode->tn_type) { case VBLK: case VCHR: nnode->tn_rdev = rdev; break; case VDIR: TAILQ_INIT(&nnode->tn_dir.tn_dirhead); MPASS(parent != nnode); MPASS(IMPLIES(parent == NULL, tmp->tm_root == NULL)); nnode->tn_dir.tn_parent = (parent == NULL) ? nnode : parent; nnode->tn_dir.tn_readdir_lastn = 0; nnode->tn_dir.tn_readdir_lastp = NULL; nnode->tn_links++; TMPFS_NODE_LOCK(nnode->tn_dir.tn_parent); nnode->tn_dir.tn_parent->tn_links++; TMPFS_NODE_UNLOCK(nnode->tn_dir.tn_parent); break; case VFIFO: /* FALLTHROUGH */ case VSOCK: break; case VLNK: MPASS(strlen(target) < MAXPATHLEN); nnode->tn_size = strlen(target); nnode->tn_link = malloc(nnode->tn_size, M_TMPFSNAME, M_WAITOK); memcpy(nnode->tn_link, target, nnode->tn_size); break; case VREG: nnode->tn_reg.tn_aobj = vm_pager_allocate(OBJT_SWAP, NULL, 0, VM_PROT_DEFAULT, 0, NULL /* XXXKIB - tmpfs needs swap reservation */); break; default: panic("tmpfs_alloc_node: type %p %d", nnode, (int)nnode->tn_type); } TMPFS_LOCK(tmp); LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries); tmp->tm_nodes_inuse++; TMPFS_UNLOCK(tmp); *node = nnode; return 0; } /* --------------------------------------------------------------------- */ /* * Destroys the node pointed to by node from the file system 'tmp'. * If the node does not belong to the given mount point, the results are * unpredicted. * * If the node references a directory; no entries are allowed because * their removal could need a recursive algorithm, something forbidden in * kernel space. Furthermore, there is not need to provide such * functionality (recursive removal) because the only primitives offered * to the user are the removal of empty directories and the deletion of * individual files. * * Note that nodes are not really deleted; in fact, when a node has been * allocated, it cannot be deleted during the whole life of the file * system. Instead, they are moved to the available list and remain there * until reused. */ void tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node) { vm_object_t uobj; #ifdef INVARIANTS TMPFS_NODE_LOCK(node); MPASS(node->tn_vnode == NULL); MPASS((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0); TMPFS_NODE_UNLOCK(node); #endif TMPFS_LOCK(tmp); LIST_REMOVE(node, tn_entries); tmp->tm_nodes_inuse--; TMPFS_UNLOCK(tmp); switch (node->tn_type) { case VNON: /* Do not do anything. VNON is provided to let the * allocation routine clean itself easily by avoiding * duplicating code in it. */ /* FALLTHROUGH */ case VBLK: /* FALLTHROUGH */ case VCHR: /* FALLTHROUGH */ case VDIR: /* FALLTHROUGH */ case VFIFO: /* FALLTHROUGH */ case VSOCK: break; case VLNK: free(node->tn_link, M_TMPFSNAME); break; case VREG: uobj = node->tn_reg.tn_aobj; if (uobj != NULL) { TMPFS_LOCK(tmp); tmp->tm_pages_used -= uobj->size; TMPFS_UNLOCK(tmp); vm_object_deallocate(uobj); } break; default: panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type); } free_unr(tmp->tm_ino_unr, node->tn_id); uma_zfree(tmp->tm_node_pool, node); } /* --------------------------------------------------------------------- */ /* * Allocates a new directory entry for the node node with a name of name. * The new directory entry is returned in *de. * * The link count of node is increased by one to reflect the new object * referencing it. * * Returns zero on success or an appropriate error code on failure. */ int tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node, const char *name, uint16_t len, struct tmpfs_dirent **de) { struct tmpfs_dirent *nde; nde = (struct tmpfs_dirent *)uma_zalloc( tmp->tm_dirent_pool, M_WAITOK); nde->td_name = malloc(len, M_TMPFSNAME, M_WAITOK); nde->td_namelen = len; memcpy(nde->td_name, name, len); nde->td_node = node; if (node != NULL) node->tn_links++; *de = nde; return 0; } /* --------------------------------------------------------------------- */ /* * Frees a directory entry. It is the caller's responsibility to destroy * the node referenced by it if needed. * * The link count of node is decreased by one to reflect the removal of an * object that referenced it. This only happens if 'node_exists' is true; * otherwise the function will not access the node referred to by the * directory entry, as it may already have been released from the outside. */ void tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de, boolean_t node_exists) { if (node_exists) { struct tmpfs_node *node; node = de->td_node; if (node != NULL) { MPASS(node->tn_links > 0); node->tn_links--; } } free(de->td_name, M_TMPFSNAME); uma_zfree(tmp->tm_dirent_pool, de); } /* --------------------------------------------------------------------- */ /* * Allocates a new vnode for the node node or returns a new reference to * an existing one if the node had already a vnode referencing it. The * resulting locked vnode is returned in *vpp. * * Returns zero on success or an appropriate error code on failure. */ int tmpfs_alloc_vp(struct mount *mp, struct tmpfs_node *node, int lkflag, struct vnode **vpp) { int error = 0; struct vnode *vp; loop: TMPFS_NODE_LOCK(node); if ((vp = node->tn_vnode) != NULL) { MPASS((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0); VI_LOCK(vp); TMPFS_NODE_UNLOCK(node); error = vget(vp, lkflag | LK_INTERLOCK, curthread); if (error != 0) { vp = NULL; goto out; } /* * Make sure the vnode is still there after * getting the interlock to avoid racing a free. */ if (node->tn_vnode == NULL || node->tn_vnode != vp) { vput(vp); goto loop; } goto out; } if ((node->tn_vpstate & TMPFS_VNODE_DOOMED) || (node->tn_type == VDIR && node->tn_dir.tn_parent == NULL)) { TMPFS_NODE_UNLOCK(node); error = ENOENT; vp = NULL; goto out; } /* * otherwise lock the vp list while we call getnewvnode * since that can block. */ if (node->tn_vpstate & TMPFS_VNODE_ALLOCATING) { node->tn_vpstate |= TMPFS_VNODE_WANT; error = msleep((caddr_t) &node->tn_vpstate, TMPFS_NODE_MTX(node), PDROP | PCATCH, "tmpfs_alloc_vp", 0); if (error) return error; goto loop; } else node->tn_vpstate |= TMPFS_VNODE_ALLOCATING; TMPFS_NODE_UNLOCK(node); /* Get a new vnode and associate it with our node. */ error = getnewvnode("tmpfs", mp, &tmpfs_vnodeop_entries, &vp); if (error != 0) goto unlock; MPASS(vp != NULL); (void) vn_lock(vp, lkflag | LK_RETRY); vp->v_data = node; vp->v_type = node->tn_type; /* Type-specific initialization. */ switch (node->tn_type) { case VBLK: /* FALLTHROUGH */ case VCHR: /* FALLTHROUGH */ case VLNK: /* FALLTHROUGH */ case VREG: /* FALLTHROUGH */ case VSOCK: break; case VFIFO: vp->v_op = &tmpfs_fifoop_entries; break; case VDIR: MPASS(node->tn_dir.tn_parent != NULL); if (node->tn_dir.tn_parent == node) vp->v_vflag |= VV_ROOT; break; default: panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type); } vnode_pager_setsize(vp, node->tn_size); error = insmntque(vp, mp); if (error) vp = NULL; unlock: TMPFS_NODE_LOCK(node); MPASS(node->tn_vpstate & TMPFS_VNODE_ALLOCATING); node->tn_vpstate &= ~TMPFS_VNODE_ALLOCATING; node->tn_vnode = vp; if (node->tn_vpstate & TMPFS_VNODE_WANT) { node->tn_vpstate &= ~TMPFS_VNODE_WANT; TMPFS_NODE_UNLOCK(node); wakeup((caddr_t) &node->tn_vpstate); } else TMPFS_NODE_UNLOCK(node); out: *vpp = vp; #ifdef INVARIANTS if (error == 0) { MPASS(*vpp != NULL && VOP_ISLOCKED(*vpp)); TMPFS_NODE_LOCK(node); MPASS(*vpp == node->tn_vnode); TMPFS_NODE_UNLOCK(node); } #endif return error; } /* --------------------------------------------------------------------- */ /* * Destroys the association between the vnode vp and the node it * references. */ void tmpfs_free_vp(struct vnode *vp) { struct tmpfs_node *node; node = VP_TO_TMPFS_NODE(vp); mtx_assert(TMPFS_NODE_MTX(node), MA_OWNED); node->tn_vnode = NULL; vp->v_data = NULL; } /* --------------------------------------------------------------------- */ /* * Allocates a new file of type 'type' and adds it to the parent directory * 'dvp'; this addition is done using the component name given in 'cnp'. * The ownership of the new file is automatically assigned based on the * credentials of the caller (through 'cnp'), the group is set based on * the parent directory and the mode is determined from the 'vap' argument. * If successful, *vpp holds a vnode to the newly created file and zero * is returned. Otherwise *vpp is NULL and the function returns an * appropriate error code. */ int tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap, struct componentname *cnp, char *target) { int error; struct tmpfs_dirent *de; struct tmpfs_mount *tmp; struct tmpfs_node *dnode; struct tmpfs_node *node; struct tmpfs_node *parent; MPASS(VOP_ISLOCKED(dvp)); MPASS(cnp->cn_flags & HASBUF); tmp = VFS_TO_TMPFS(dvp->v_mount); dnode = VP_TO_TMPFS_DIR(dvp); *vpp = NULL; /* If the entry we are creating is a directory, we cannot overflow * the number of links of its parent, because it will get a new * link. */ if (vap->va_type == VDIR) { /* Ensure that we do not overflow the maximum number of links * imposed by the system. */ MPASS(dnode->tn_links <= LINK_MAX); if (dnode->tn_links == LINK_MAX) { error = EMLINK; goto out; } parent = dnode; MPASS(parent != NULL); } else parent = NULL; /* Allocate a node that represents the new file. */ error = tmpfs_alloc_node(tmp, vap->va_type, cnp->cn_cred->cr_uid, dnode->tn_gid, vap->va_mode, parent, target, vap->va_rdev, &node); if (error != 0) goto out; /* Allocate a directory entry that points to the new file. */ error = tmpfs_alloc_dirent(tmp, node, cnp->cn_nameptr, cnp->cn_namelen, &de); if (error != 0) { tmpfs_free_node(tmp, node); goto out; } /* Allocate a vnode for the new file. */ error = tmpfs_alloc_vp(dvp->v_mount, node, LK_EXCLUSIVE, vpp); if (error != 0) { tmpfs_free_dirent(tmp, de, TRUE); tmpfs_free_node(tmp, node); goto out; } /* Now that all required items are allocated, we can proceed to * insert the new node into the directory, an operation that * cannot fail. */ if (cnp->cn_flags & ISWHITEOUT) tmpfs_dir_whiteout_remove(dvp, cnp); tmpfs_dir_attach(dvp, de); out: return error; } /* --------------------------------------------------------------------- */ /* * Attaches the directory entry de to the directory represented by vp. * Note that this does not change the link count of the node pointed by * the directory entry, as this is done by tmpfs_alloc_dirent. */ void tmpfs_dir_attach(struct vnode *vp, struct tmpfs_dirent *de) { struct tmpfs_node *dnode; ASSERT_VOP_ELOCKED(vp, __func__); dnode = VP_TO_TMPFS_DIR(vp); TAILQ_INSERT_TAIL(&dnode->tn_dir.tn_dirhead, de, td_entries); dnode->tn_size += sizeof(struct tmpfs_dirent); dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \ TMPFS_NODE_MODIFIED; } /* --------------------------------------------------------------------- */ /* * Detaches the directory entry de from the directory represented by vp. * Note that this does not change the link count of the node pointed by * the directory entry, as this is done by tmpfs_free_dirent. */ void tmpfs_dir_detach(struct vnode *vp, struct tmpfs_dirent *de) { struct tmpfs_node *dnode; ASSERT_VOP_ELOCKED(vp, __func__); dnode = VP_TO_TMPFS_DIR(vp); if (dnode->tn_dir.tn_readdir_lastp == de) { dnode->tn_dir.tn_readdir_lastn = 0; dnode->tn_dir.tn_readdir_lastp = NULL; } TAILQ_REMOVE(&dnode->tn_dir.tn_dirhead, de, td_entries); dnode->tn_size -= sizeof(struct tmpfs_dirent); dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \ TMPFS_NODE_MODIFIED; } /* --------------------------------------------------------------------- */ /* * Looks for a directory entry in the directory represented by node. * 'cnp' describes the name of the entry to look for. Note that the . * and .. components are not allowed as they do not physically exist * within directories. * * Returns a pointer to the entry when found, otherwise NULL. */ struct tmpfs_dirent * tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f, struct componentname *cnp) { boolean_t found; struct tmpfs_dirent *de; MPASS(IMPLIES(cnp->cn_namelen == 1, cnp->cn_nameptr[0] != '.')); MPASS(IMPLIES(cnp->cn_namelen == 2, !(cnp->cn_nameptr[0] == '.' && cnp->cn_nameptr[1] == '.'))); TMPFS_VALIDATE_DIR(node); found = 0; TAILQ_FOREACH(de, &node->tn_dir.tn_dirhead, td_entries) { if (f != NULL && de->td_node != f) continue; MPASS(cnp->cn_namelen < 0xffff); if (de->td_namelen == (uint16_t)cnp->cn_namelen && bcmp(de->td_name, cnp->cn_nameptr, de->td_namelen) == 0) { found = 1; break; } } node->tn_status |= TMPFS_NODE_ACCESSED; return found ? de : NULL; } /* --------------------------------------------------------------------- */ /* * Helper function for tmpfs_readdir. Creates a '.' entry for the given * directory and returns it in the uio space. The function returns 0 * on success, -1 if there was not enough space in the uio structure to * hold the directory entry or an appropriate error code if another * error happens. */ int tmpfs_dir_getdotdent(struct tmpfs_node *node, struct uio *uio) { int error; struct dirent dent; TMPFS_VALIDATE_DIR(node); MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOT); dent.d_fileno = node->tn_id; dent.d_type = DT_DIR; dent.d_namlen = 1; dent.d_name[0] = '.'; dent.d_name[1] = '\0'; dent.d_reclen = GENERIC_DIRSIZ(&dent); if (dent.d_reclen > uio->uio_resid) error = -1; else { error = uiomove(&dent, dent.d_reclen, uio); if (error == 0) uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT; } node->tn_status |= TMPFS_NODE_ACCESSED; return error; } /* --------------------------------------------------------------------- */ /* * Helper function for tmpfs_readdir. Creates a '..' entry for the given * directory and returns it in the uio space. The function returns 0 * on success, -1 if there was not enough space in the uio structure to * hold the directory entry or an appropriate error code if another * error happens. */ int tmpfs_dir_getdotdotdent(struct tmpfs_node *node, struct uio *uio) { int error; struct dirent dent; TMPFS_VALIDATE_DIR(node); MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT); /* * Return ENOENT if the current node is already removed. */ TMPFS_ASSERT_LOCKED(node); if (node->tn_dir.tn_parent == NULL) { return (ENOENT); } TMPFS_NODE_LOCK(node->tn_dir.tn_parent); dent.d_fileno = node->tn_dir.tn_parent->tn_id; TMPFS_NODE_UNLOCK(node->tn_dir.tn_parent); dent.d_type = DT_DIR; dent.d_namlen = 2; dent.d_name[0] = '.'; dent.d_name[1] = '.'; dent.d_name[2] = '\0'; dent.d_reclen = GENERIC_DIRSIZ(&dent); if (dent.d_reclen > uio->uio_resid) error = -1; else { error = uiomove(&dent, dent.d_reclen, uio); if (error == 0) { struct tmpfs_dirent *de; de = TAILQ_FIRST(&node->tn_dir.tn_dirhead); if (de == NULL) uio->uio_offset = TMPFS_DIRCOOKIE_EOF; else uio->uio_offset = tmpfs_dircookie(de); } } node->tn_status |= TMPFS_NODE_ACCESSED; return error; } /* --------------------------------------------------------------------- */ /* * Lookup a directory entry by its associated cookie. */ struct tmpfs_dirent * tmpfs_dir_lookupbycookie(struct tmpfs_node *node, off_t cookie) { struct tmpfs_dirent *de; if (cookie == node->tn_dir.tn_readdir_lastn && node->tn_dir.tn_readdir_lastp != NULL) { return node->tn_dir.tn_readdir_lastp; } TAILQ_FOREACH(de, &node->tn_dir.tn_dirhead, td_entries) { if (tmpfs_dircookie(de) == cookie) { break; } } return de; } /* --------------------------------------------------------------------- */ /* * Helper function for tmpfs_readdir. Returns as much directory entries * as can fit in the uio space. The read starts at uio->uio_offset. * The function returns 0 on success, -1 if there was not enough space * in the uio structure to hold the directory entry or an appropriate * error code if another error happens. */ int tmpfs_dir_getdents(struct tmpfs_node *node, struct uio *uio, off_t *cntp) { int error; off_t startcookie; struct tmpfs_dirent *de; TMPFS_VALIDATE_DIR(node); /* Locate the first directory entry we have to return. We have cached * the last readdir in the node, so use those values if appropriate. * Otherwise do a linear scan to find the requested entry. */ startcookie = uio->uio_offset; MPASS(startcookie != TMPFS_DIRCOOKIE_DOT); MPASS(startcookie != TMPFS_DIRCOOKIE_DOTDOT); if (startcookie == TMPFS_DIRCOOKIE_EOF) { return 0; } else { de = tmpfs_dir_lookupbycookie(node, startcookie); } if (de == NULL) { return EINVAL; } /* Read as much entries as possible; i.e., until we reach the end of * the directory or we exhaust uio space. */ do { struct dirent d; /* Create a dirent structure representing the current * tmpfs_node and fill it. */ if (de->td_node == NULL) { d.d_fileno = 1; d.d_type = DT_WHT; } else { d.d_fileno = de->td_node->tn_id; switch (de->td_node->tn_type) { case VBLK: d.d_type = DT_BLK; break; case VCHR: d.d_type = DT_CHR; break; case VDIR: d.d_type = DT_DIR; break; case VFIFO: d.d_type = DT_FIFO; break; case VLNK: d.d_type = DT_LNK; break; case VREG: d.d_type = DT_REG; break; case VSOCK: d.d_type = DT_SOCK; break; default: panic("tmpfs_dir_getdents: type %p %d", de->td_node, (int)de->td_node->tn_type); } } d.d_namlen = de->td_namelen; MPASS(de->td_namelen < sizeof(d.d_name)); (void)memcpy(d.d_name, de->td_name, de->td_namelen); d.d_name[de->td_namelen] = '\0'; d.d_reclen = GENERIC_DIRSIZ(&d); /* Stop reading if the directory entry we are treating is * bigger than the amount of data that can be returned. */ if (d.d_reclen > uio->uio_resid) { error = -1; break; } /* Copy the new dirent structure into the output buffer and * advance pointers. */ error = uiomove(&d, d.d_reclen, uio); if (error == 0) { (*cntp)++; de = TAILQ_NEXT(de, td_entries); } } while (error == 0 && uio->uio_resid > 0 && de != NULL); /* Update the offset and cache. */ if (de == NULL) { uio->uio_offset = TMPFS_DIRCOOKIE_EOF; node->tn_dir.tn_readdir_lastn = 0; node->tn_dir.tn_readdir_lastp = NULL; } else { node->tn_dir.tn_readdir_lastn = uio->uio_offset = tmpfs_dircookie(de); node->tn_dir.tn_readdir_lastp = de; } node->tn_status |= TMPFS_NODE_ACCESSED; return error; } int tmpfs_dir_whiteout_add(struct vnode *dvp, struct componentname *cnp) { struct tmpfs_dirent *de; int error; error = tmpfs_alloc_dirent(VFS_TO_TMPFS(dvp->v_mount), NULL, cnp->cn_nameptr, cnp->cn_namelen, &de); if (error != 0) return (error); tmpfs_dir_attach(dvp, de); return (0); } void tmpfs_dir_whiteout_remove(struct vnode *dvp, struct componentname *cnp) { struct tmpfs_dirent *de; de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(dvp), NULL, cnp); MPASS(de != NULL && de->td_node == NULL); tmpfs_dir_detach(dvp, de); tmpfs_free_dirent(VFS_TO_TMPFS(dvp->v_mount), de, TRUE); } /* --------------------------------------------------------------------- */ /* * Resizes the aobj associated with the regular file pointed to by 'vp' to the * size 'newsize'. 'vp' must point to a vnode that represents a regular file. * 'newsize' must be positive. * * Returns zero on success or an appropriate error code on failure. */ int tmpfs_reg_resize(struct vnode *vp, off_t newsize, boolean_t ignerr) { struct tmpfs_mount *tmp; struct tmpfs_node *node; vm_object_t uobj; vm_page_t m, ma[1]; vm_pindex_t idx, newpages, oldpages; off_t oldsize; int base, rv; MPASS(vp->v_type == VREG); MPASS(newsize >= 0); node = VP_TO_TMPFS_NODE(vp); uobj = node->tn_reg.tn_aobj; tmp = VFS_TO_TMPFS(vp->v_mount); /* * Convert the old and new sizes to the number of pages needed to * store them. It may happen that we do not need to do anything * because the last allocated page can accommodate the change on * its own. */ oldsize = node->tn_size; oldpages = OFF_TO_IDX(oldsize + PAGE_MASK); MPASS(oldpages == uobj->size); newpages = OFF_TO_IDX(newsize + PAGE_MASK); if (newpages > oldpages && tmpfs_pages_check_avail(tmp, newpages - oldpages) == 0) return (ENOSPC); VM_OBJECT_LOCK(uobj); if (newsize < oldsize) { /* * Zero the truncated part of the last page. */ base = newsize & PAGE_MASK; if (base != 0) { idx = OFF_TO_IDX(newsize); retry: m = vm_page_lookup(uobj, idx); if (m != NULL) { if ((m->oflags & VPO_BUSY) != 0 || m->busy != 0) { vm_page_sleep(m, "tmfssz"); goto retry; } MPASS(m->valid == VM_PAGE_BITS_ALL); } else if (vm_pager_has_page(uobj, idx, NULL, NULL)) { m = vm_page_alloc(uobj, idx, VM_ALLOC_NORMAL); if (m == NULL) { VM_OBJECT_UNLOCK(uobj); VM_WAIT; VM_OBJECT_LOCK(uobj); goto retry; } else if (m->valid != VM_PAGE_BITS_ALL) { ma[0] = m; rv = vm_pager_get_pages(uobj, ma, 1, 0); m = vm_page_lookup(uobj, idx); } else /* A cached page was reactivated. */ rv = VM_PAGER_OK; vm_page_lock(m); if (rv == VM_PAGER_OK) { vm_page_deactivate(m); vm_page_unlock(m); vm_page_wakeup(m); } else { vm_page_free(m); vm_page_unlock(m); if (ignerr) m = NULL; else { VM_OBJECT_UNLOCK(uobj); return (EIO); } } } if (m != NULL) { pmap_zero_page_area(m, base, PAGE_SIZE - base); vm_page_dirty(m); vm_pager_page_unswapped(m); } } /* * Release any swap space and free any whole pages. */ if (newpages < oldpages) { swap_pager_freespace(uobj, newpages, oldpages - newpages); vm_object_page_remove(uobj, newpages, 0, 0); } } uobj->size = newpages; VM_OBJECT_UNLOCK(uobj); TMPFS_LOCK(tmp); tmp->tm_pages_used += (newpages - oldpages); TMPFS_UNLOCK(tmp); node->tn_size = newsize; vnode_pager_setsize(vp, newsize); return (0); } /* --------------------------------------------------------------------- */ /* * Change flags of the given vnode. * Caller should execute tmpfs_update on vp after a successful execution. * The vnode must be locked on entry and remain locked on exit. */ int tmpfs_chflags(struct vnode *vp, int flags, struct ucred *cred, struct thread *p) { int error; struct tmpfs_node *node; MPASS(VOP_ISLOCKED(vp)); node = VP_TO_TMPFS_NODE(vp); /* Disallow this operation if the file system is mounted read-only. */ if (vp->v_mount->mnt_flag & MNT_RDONLY) return EROFS; /* * Callers may only modify the file flags on objects they * have VADMIN rights for. */ if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) return (error); /* * Unprivileged processes are not permitted to unset system * flags, or modify flags if any system flags are set. */ if (!priv_check_cred(cred, PRIV_VFS_SYSFLAGS, 0)) { if (node->tn_flags & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) { error = securelevel_gt(cred, 0); if (error) return (error); } /* Snapshot flag cannot be set or cleared */ if (((flags & SF_SNAPSHOT) != 0 && (node->tn_flags & SF_SNAPSHOT) == 0) || ((flags & SF_SNAPSHOT) == 0 && (node->tn_flags & SF_SNAPSHOT) != 0)) return (EPERM); node->tn_flags = flags; } else { if (node->tn_flags & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) || (flags & UF_SETTABLE) != flags) return (EPERM); node->tn_flags &= SF_SETTABLE; node->tn_flags |= (flags & UF_SETTABLE); } node->tn_status |= TMPFS_NODE_CHANGED; MPASS(VOP_ISLOCKED(vp)); return 0; } /* --------------------------------------------------------------------- */ /* * Change access mode on the given vnode. * Caller should execute tmpfs_update on vp after a successful execution. * The vnode must be locked on entry and remain locked on exit. */ int tmpfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct thread *p) { int error; struct tmpfs_node *node; MPASS(VOP_ISLOCKED(vp)); node = VP_TO_TMPFS_NODE(vp); /* Disallow this operation if the file system is mounted read-only. */ if (vp->v_mount->mnt_flag & MNT_RDONLY) return EROFS; /* Immutable or append-only files cannot be modified, either. */ if (node->tn_flags & (IMMUTABLE | APPEND)) return EPERM; /* * To modify the permissions on a file, must possess VADMIN * for that file. */ if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) return (error); /* * Privileged processes may set the sticky bit on non-directories, * as well as set the setgid bit on a file with a group that the * process is not a member of. */ if (vp->v_type != VDIR && (mode & S_ISTXT)) { if (priv_check_cred(cred, PRIV_VFS_STICKYFILE, 0)) return (EFTYPE); } if (!groupmember(node->tn_gid, cred) && (mode & S_ISGID)) { error = priv_check_cred(cred, PRIV_VFS_SETGID, 0); if (error) return (error); } node->tn_mode &= ~ALLPERMS; node->tn_mode |= mode & ALLPERMS; node->tn_status |= TMPFS_NODE_CHANGED; MPASS(VOP_ISLOCKED(vp)); return 0; } /* --------------------------------------------------------------------- */ /* * Change ownership of the given vnode. At least one of uid or gid must * be different than VNOVAL. If one is set to that value, the attribute * is unchanged. * Caller should execute tmpfs_update on vp after a successful execution. * The vnode must be locked on entry and remain locked on exit. */ int tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred, struct thread *p) { int error; struct tmpfs_node *node; uid_t ouid; gid_t ogid; MPASS(VOP_ISLOCKED(vp)); node = VP_TO_TMPFS_NODE(vp); /* Assign default values if they are unknown. */ MPASS(uid != VNOVAL || gid != VNOVAL); if (uid == VNOVAL) uid = node->tn_uid; if (gid == VNOVAL) gid = node->tn_gid; MPASS(uid != VNOVAL && gid != VNOVAL); /* Disallow this operation if the file system is mounted read-only. */ if (vp->v_mount->mnt_flag & MNT_RDONLY) return EROFS; /* Immutable or append-only files cannot be modified, either. */ if (node->tn_flags & (IMMUTABLE | APPEND)) return EPERM; /* * To modify the ownership of a file, must possess VADMIN for that * file. */ if ((error = VOP_ACCESS(vp, VADMIN, cred, p))) return (error); /* * To change the owner of a file, or change the group of a file to a * group of which we are not a member, the caller must have * privilege. */ if ((uid != node->tn_uid || (gid != node->tn_gid && !groupmember(gid, cred))) && (error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0))) return (error); ogid = node->tn_gid; ouid = node->tn_uid; node->tn_uid = uid; node->tn_gid = gid; node->tn_status |= TMPFS_NODE_CHANGED; if ((node->tn_mode & (S_ISUID | S_ISGID)) && (ouid != uid || ogid != gid)) { if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0)) node->tn_mode &= ~(S_ISUID | S_ISGID); } MPASS(VOP_ISLOCKED(vp)); return 0; } /* --------------------------------------------------------------------- */ /* * Change size of the given vnode. * Caller should execute tmpfs_update on vp after a successful execution. * The vnode must be locked on entry and remain locked on exit. */ int tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred, struct thread *p) { int error; struct tmpfs_node *node; MPASS(VOP_ISLOCKED(vp)); node = VP_TO_TMPFS_NODE(vp); /* Decide whether this is a valid operation based on the file type. */ error = 0; switch (vp->v_type) { case VDIR: return EISDIR; case VREG: if (vp->v_mount->mnt_flag & MNT_RDONLY) return EROFS; break; case VBLK: /* FALLTHROUGH */ case VCHR: /* FALLTHROUGH */ case VFIFO: /* Allow modifications of special files even if in the file * system is mounted read-only (we are not modifying the * files themselves, but the objects they represent). */ return 0; default: /* Anything else is unsupported. */ return EOPNOTSUPP; } /* Immutable or append-only files cannot be modified, either. */ if (node->tn_flags & (IMMUTABLE | APPEND)) return EPERM; error = tmpfs_truncate(vp, size); /* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents * for us, as will update tn_status; no need to do that here. */ MPASS(VOP_ISLOCKED(vp)); return error; } /* --------------------------------------------------------------------- */ /* * Change access and modification times of the given vnode. * Caller should execute tmpfs_update on vp after a successful execution. * The vnode must be locked on entry and remain locked on exit. */ int tmpfs_chtimes(struct vnode *vp, struct timespec *atime, struct timespec *mtime, struct timespec *birthtime, int vaflags, struct ucred *cred, struct thread *l) { int error; struct tmpfs_node *node; MPASS(VOP_ISLOCKED(vp)); node = VP_TO_TMPFS_NODE(vp); /* Disallow this operation if the file system is mounted read-only. */ if (vp->v_mount->mnt_flag & MNT_RDONLY) return EROFS; /* Immutable or append-only files cannot be modified, either. */ if (node->tn_flags & (IMMUTABLE | APPEND)) return EPERM; /* Determine if the user have proper privilege to update time. */ if (vaflags & VA_UTIMES_NULL) { error = VOP_ACCESS(vp, VADMIN, cred, l); if (error) error = VOP_ACCESS(vp, VWRITE, cred, l); } else error = VOP_ACCESS(vp, VADMIN, cred, l); if (error) return (error); if (atime->tv_sec != VNOVAL && atime->tv_nsec != VNOVAL) node->tn_status |= TMPFS_NODE_ACCESSED; if (mtime->tv_sec != VNOVAL && mtime->tv_nsec != VNOVAL) node->tn_status |= TMPFS_NODE_MODIFIED; if (birthtime->tv_nsec != VNOVAL && birthtime->tv_nsec != VNOVAL) node->tn_status |= TMPFS_NODE_MODIFIED; tmpfs_itimes(vp, atime, mtime); if (birthtime->tv_nsec != VNOVAL && birthtime->tv_nsec != VNOVAL) node->tn_birthtime = *birthtime; MPASS(VOP_ISLOCKED(vp)); return 0; } /* --------------------------------------------------------------------- */ /* Sync timestamps */ void tmpfs_itimes(struct vnode *vp, const struct timespec *acc, const struct timespec *mod) { struct tmpfs_node *node; struct timespec now; node = VP_TO_TMPFS_NODE(vp); if ((node->tn_status & (TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED)) == 0) return; vfs_timestamp(&now); if (node->tn_status & TMPFS_NODE_ACCESSED) { if (acc == NULL) acc = &now; node->tn_atime = *acc; } if (node->tn_status & TMPFS_NODE_MODIFIED) { if (mod == NULL) mod = &now; node->tn_mtime = *mod; } if (node->tn_status & TMPFS_NODE_CHANGED) { node->tn_ctime = now; } node->tn_status &= ~(TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED); } /* --------------------------------------------------------------------- */ void tmpfs_update(struct vnode *vp) { tmpfs_itimes(vp, NULL, NULL); } /* --------------------------------------------------------------------- */ int tmpfs_truncate(struct vnode *vp, off_t length) { int error; struct tmpfs_node *node; node = VP_TO_TMPFS_NODE(vp); if (length < 0) { error = EINVAL; goto out; } if (node->tn_size == length) { error = 0; goto out; } if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize) return (EFBIG); error = tmpfs_reg_resize(vp, length, FALSE); if (error == 0) { node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED; } out: tmpfs_update(vp); return error; }