/* $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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static ino_t tmpfs_fetch_ino(struct tmpfs_mount *); static int tmpfs_dirtree_compare(struct tmpfs_dirent *a, struct tmpfs_dirent *b); RB_GENERATE(tmpfs_dirtree, tmpfs_dirent, rb_node, tmpfs_dirtree_compare); static int tmpfs_dirtree_compare_cookie(struct tmpfs_dirent *a, struct tmpfs_dirent *b); RB_GENERATE(tmpfs_dirtree_cookie, tmpfs_dirent, rb_cookienode, tmpfs_dirtree_compare_cookie); /* --------------------------------------------------------------------- */ /* * 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, char *target, int rmajor, int rminor, struct tmpfs_node **node) { struct tmpfs_node *nnode; struct timespec ts; dev_t rdev; KKASSERT(IFF(type == VLNK, target != NULL)); KKASSERT(IFF(type == VBLK || type == VCHR, rmajor != VNOVAL)); if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max) return (ENOSPC); nnode = kmalloc_obj(sizeof(struct tmpfs_node), tmp->tm_node_zone, M_WAITOK | M_ZERO | M_NULLOK); if (nnode == NULL) return (ENOSPC); tmpfs_node_init(nnode); /* Generic initialization. */ nnode->tn_type = type; vfs_timestamp(&ts); nnode->tn_ctime = nnode->tn_mtime = nnode->tn_atime = ts.tv_sec; nnode->tn_ctimensec = nnode->tn_mtimensec = nnode->tn_atimensec = ts.tv_nsec; nnode->tn_uid = uid; nnode->tn_gid = gid; nnode->tn_mode = mode; nnode->tn_id = tmpfs_fetch_ino(tmp); nnode->tn_advlock.init_done = 0; KKASSERT(nnode->tn_links == 0); /* Type-specific initialization. */ switch (nnode->tn_type) { case VBLK: case VCHR: rdev = makeudev(rmajor, rminor); if (rdev == NOUDEV) { tmpfs_node_uninit(nnode); kfree_obj(nnode, tmp->tm_node_zone); return(EINVAL); } nnode->tn_rdev = rdev; break; case VDIR: RB_INIT(&nnode->tn_dir.tn_dirtree); RB_INIT(&nnode->tn_dir.tn_cookietree); nnode->tn_dir.tn_parent = NULL; nnode->tn_size = 0; break; case VFIFO: /* FALLTHROUGH */ case VSOCK: break; case VLNK: nnode->tn_size = strlen(target); nnode->tn_link = kmalloc(nnode->tn_size + 1, tmp->tm_name_zone, M_WAITOK | M_NULLOK); if (nnode->tn_link == NULL) { tmpfs_node_uninit(nnode); kfree_obj(nnode, tmp->tm_node_zone); return (ENOSPC); } bcopy(target, nnode->tn_link, nnode->tn_size); nnode->tn_link[nnode->tn_size] = '\0'; break; case VREG: nnode->tn_reg.tn_aobj = swap_pager_alloc(NULL, 0, VM_PROT_DEFAULT, 0); nnode->tn_reg.tn_aobj_pages = 0; nnode->tn_size = 0; vm_object_set_flag(nnode->tn_reg.tn_aobj, OBJ_NOPAGEIN); break; default: panic("tmpfs_alloc_node: type %p %d", nnode, (int)nnode->tn_type); } TMPFS_NODE_LOCK(nnode); TMPFS_LOCK(tmp); LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries); tmp->tm_nodes_inuse++; TMPFS_UNLOCK(tmp); TMPFS_NODE_UNLOCK(nnode); *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. * * A caller must have TMPFS_NODE_LOCK(node) and this function unlocks it. */ void tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node) { vm_pindex_t pages = 0; #ifdef INVARIANTS TMPFS_ASSERT_ELOCKED(node); KKASSERT(node->tn_vnode == NULL); #endif TMPFS_LOCK(tmp); LIST_REMOVE(node, tn_entries); tmp->tm_nodes_inuse--; TMPFS_UNLOCK(tmp); TMPFS_NODE_UNLOCK(node); /* Caller has this lock */ 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 */ break; case VDIR: /* * The parent link can be NULL if this is the root * node or if it is a directory node that was rmdir'd. * * XXX what if node is a directory which still contains * directory entries (e.g. due to a forced umount) ? */ node->tn_size = 0; KKASSERT(node->tn_dir.tn_parent == NULL); /* * If the root node is being destroyed don't leave a * dangling pointer in tmpfs_mount. */ if (node == tmp->tm_root) tmp->tm_root = NULL; break; case VFIFO: /* FALLTHROUGH */ case VSOCK: break; case VLNK: kfree(node->tn_link, tmp->tm_name_zone); node->tn_link = NULL; node->tn_size = 0; break; case VREG: if (node->tn_reg.tn_aobj != NULL) vm_object_deallocate(node->tn_reg.tn_aobj); node->tn_reg.tn_aobj = NULL; pages = node->tn_reg.tn_aobj_pages; break; default: panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type); } /* * Clean up fields as a safety before destroying the entry. */ tmpfs_node_uninit(node); kfree_obj(node, tmp->tm_node_zone); /* node is now invalid */ if (pages) atomic_add_long(&tmp->tm_pages_used, -(long)pages); } /* --------------------------------------------------------------------- */ /* * 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 = kmalloc_obj(sizeof(struct tmpfs_dirent), tmp->tm_dirent_zone, M_WAITOK); nde->td_name = kmalloc(len + 1, tmp->tm_name_zone, M_WAITOK | M_NULLOK); if (nde->td_name == NULL) { kfree_obj(nde, tmp->tm_dirent_zone); *de = NULL; return (ENOSPC); } nde->td_namelen = len; bcopy(name, nde->td_name, len); nde->td_name[len] = '\0'; nde->td_node = node; atomic_add_int(&node->tn_links, 1); *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) { struct tmpfs_node *node; node = de->td_node; KKASSERT(node->tn_links > 0); atomic_add_int(&node->tn_links, -1); kfree(de->td_name, tmp->tm_name_zone); de->td_namelen = 0; de->td_name = NULL; de->td_node = NULL; kfree_obj(de, tmp->tm_dirent_zone); } /* --------------------------------------------------------------------- */ /* * 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. * * The caller must ensure that node cannot go away (usually by holding * the related directory entry). * * If dnode is non-NULL this routine avoids deadlocking against it but * can return EAGAIN. Caller must try again. The dnode lock will cycle * in this case, it remains locked on return in all cases. dnode must * be shared-locked. */ int tmpfs_alloc_vp(struct mount *mp, struct tmpfs_node *dnode, struct tmpfs_node *node, int lkflag, struct vnode **vpp) { int error = 0; struct vnode *vp; loop: vp = NULL; if (node->tn_vnode == NULL) { error = getnewvnode(VT_TMPFS, mp, &vp, VLKTIMEOUT, LK_CANRECURSE); if (error) goto out; } /* * Interlocked extraction from node. This can race many things. * We have to get a soft reference on the vnode while we hold * the node locked, then acquire it properly and check for races. */ TMPFS_NODE_LOCK(node); if (node->tn_vnode) { if (vp) { vp->v_type = VBAD; vx_put(vp); } vp = node->tn_vnode; KKASSERT((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0); vhold(vp); TMPFS_NODE_UNLOCK(node); if (dnode) { /* * Special-case handling to avoid deadlocking against * dnode. This case has been validated and occurs * every so often during synth builds and in other * situations. */ if (vget(vp, (lkflag & ~LK_RETRY) | LK_NOWAIT | LK_EXCLUSIVE) != 0) { TMPFS_NODE_UNLOCK(dnode); if (vget(vp, (lkflag & ~LK_RETRY) | LK_SLEEPFAIL | LK_EXCLUSIVE) == 0) { vput(vp); } vdrop(vp); TMPFS_NODE_LOCK_SH(dnode); return EAGAIN; } } else { /* * Normal path */ if (vget(vp, lkflag | LK_EXCLUSIVE) != 0) { vdrop(vp); goto loop; } } if (node->tn_vnode != vp) { vput(vp); vdrop(vp); goto loop; } vdrop(vp); goto out; } /* * We need to assign node->tn_vnode. If vp is NULL, loop up to * allocate the vp. This can happen due to SMP races. */ if (vp == NULL) { TMPFS_NODE_UNLOCK(node); goto loop; } /* * This should never happen. */ if (node->tn_vpstate & TMPFS_VNODE_DOOMED) { TMPFS_NODE_UNLOCK(node); vp->v_type = VBAD; vx_put(vp); error = ENOENT; goto out; } KKASSERT(node->tn_vnode == NULL); KKASSERT(vp != NULL); vp->v_data = node; vp->v_type = node->tn_type; /* Type-specific initialization. */ switch (node->tn_type) { case VBLK: /* FALLTHROUGH */ case VCHR: /* FALLTHROUGH */ case VSOCK: break; case VREG: /* * VMIO is mandatory. Tmpfs also supports KVABIO * for its tmpfs_strategy(). */ vsetflags(vp, VKVABIO); vinitvmio(vp, node->tn_size, node->tn_blksize, -1); break; case VLNK: break; case VFIFO: vp->v_ops = &mp->mnt_vn_fifo_ops; break; case VDIR: break; default: panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type); } node->tn_vnode = vp; TMPFS_NODE_UNLOCK(node); vx_downgrade(vp); out: *vpp = vp; KKASSERT(IFF(error == 0, *vpp != NULL && vn_islocked(*vpp))); return error; } /* --------------------------------------------------------------------- */ /* * 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 namecache *ncp, struct ucred *cred, char *target) { int error; struct tmpfs_dirent *de; struct tmpfs_mount *tmp; struct tmpfs_node *dnode; struct tmpfs_node *node; tmp = VFS_TO_TMPFS(dvp->v_mount); dnode = VP_TO_TMPFS_DIR(dvp); *vpp = NULL; TMPFS_NODE_LOCK(dnode); /* * If the directory was removed but a process was CD'd into it, * we do not allow any more file/dir creation within it. Otherwise * we will lose track of it. */ KKASSERT(dnode->tn_type == VDIR); if (dnode != tmp->tm_root && dnode->tn_dir.tn_parent == NULL) { TMPFS_NODE_UNLOCK(dnode); return ENOENT; } /* * Make sure the link count does not overflow. */ if (vap->va_type == VDIR && dnode->tn_links >= LINK_MAX) { TMPFS_NODE_UNLOCK(dnode); return EMLINK; } /* Allocate a node that represents the new file. */ error = tmpfs_alloc_node(tmp, vap->va_type, cred->cr_uid, dnode->tn_gid, vap->va_mode, target, vap->va_rmajor, vap->va_rminor, &node); if (error != 0) { TMPFS_NODE_UNLOCK(dnode); return error; } TMPFS_NODE_LOCK(node); /* Allocate a directory entry that points to the new file. */ error = tmpfs_alloc_dirent(tmp, node, ncp->nc_name, ncp->nc_nlen, &de); if (error != 0) { TMPFS_NODE_UNLOCK(dnode); tmpfs_free_node(tmp, node); /* eats node lock */ return error; } /* Allocate a vnode for the new file. */ error = tmpfs_alloc_vp(dvp->v_mount, NULL, node, LK_EXCLUSIVE, vpp); if (error != 0) { TMPFS_NODE_UNLOCK(dnode); tmpfs_free_dirent(tmp, de); tmpfs_free_node(tmp, node); /* eats node lock */ return error; } /* * Now that all required items are allocated, we can proceed to * insert the new node into the directory, an operation that * cannot fail. */ tmpfs_dir_attach_locked(dnode, de); TMPFS_NODE_UNLOCK(dnode); TMPFS_NODE_UNLOCK(node); return error; } /* --------------------------------------------------------------------- */ /* * Attaches the directory entry de to the directory represented by dnode. * 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. * * dnode must be locked. */ void tmpfs_dir_attach_locked(struct tmpfs_node *dnode, struct tmpfs_dirent *de) { struct tmpfs_node *node = de->td_node; struct tmpfs_dirent *de2; if (node && node->tn_type == VDIR) { TMPFS_NODE_LOCK(node); atomic_add_int(&node->tn_links, 1); node->tn_status |= TMPFS_NODE_CHANGED; node->tn_dir.tn_parent = dnode; atomic_add_int(&dnode->tn_links, 1); TMPFS_NODE_UNLOCK(node); } de2 = RB_INSERT(tmpfs_dirtree, &dnode->tn_dir.tn_dirtree, de); KASSERT(de2 == NULL, ("tmpfs_dir_attach_lockedA: duplicate insertion of %p, has %p\n", de, de2)); de2 = RB_INSERT(tmpfs_dirtree_cookie, &dnode->tn_dir.tn_cookietree, de); KASSERT(de2 == NULL, ("tmpfs_dir_attach_lockedB: duplicate insertion of %p, has %p\n", de, de2)); 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 dnode. * 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. * * dnode must be locked. */ void tmpfs_dir_detach_locked(struct tmpfs_node *dnode, struct tmpfs_dirent *de) { struct tmpfs_node *node = de->td_node; RB_REMOVE(tmpfs_dirtree, &dnode->tn_dir.tn_dirtree, de); RB_REMOVE(tmpfs_dirtree_cookie, &dnode->tn_dir.tn_cookietree, de); dnode->tn_size -= sizeof(struct tmpfs_dirent); dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED; /* * Clean out the tn_parent pointer immediately when removing a * directory. * * Removal of the parent linkage also cleans out the extra tn_links * count we had on both node and dnode. * * node can be NULL (typ during a forced umount), in which case * the mount code is dealing with the linkages from a linked list * scan. */ if (node && node->tn_type == VDIR && node->tn_dir.tn_parent) { TMPFS_NODE_LOCK(node); KKASSERT(node->tn_dir.tn_parent == dnode); atomic_add_int(&dnode->tn_links, -1); atomic_add_int(&node->tn_links, -1); node->tn_dir.tn_parent = NULL; TMPFS_NODE_UNLOCK(node); } } /* --------------------------------------------------------------------- */ /* * Looks for a directory entry in the directory represented by node. * 'ncp' 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. * * Caller must hold the node locked (shared ok) */ struct tmpfs_dirent * tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f, struct namecache *ncp) { struct tmpfs_dirent *de; int len = ncp->nc_nlen; struct tmpfs_dirent wanted; wanted.td_namelen = len; wanted.td_name = ncp->nc_name; TMPFS_VALIDATE_DIR(node); de = RB_FIND(tmpfs_dirtree, &node->tn_dir.tn_dirtree, &wanted); KASSERT((f == NULL || de == NULL || f == de->td_node), ("tmpfs_dir_lookup: Incorrect node %p %p %p", f, de, (de ? de->td_node : NULL))); return de; } /* --------------------------------------------------------------------- */ /* * 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; TMPFS_VALIDATE_DIR(node); KKASSERT(uio->uio_offset == TMPFS_DIRCOOKIE_DOT); if (vop_write_dirent(&error, uio, node->tn_id, DT_DIR, 1, ".")) return -1; if (error == 0) uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT; 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_mount *tmp, struct tmpfs_node *node, struct uio *uio) { int error; ino_t d_ino; TMPFS_VALIDATE_DIR(node); KKASSERT(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT); if (node->tn_dir.tn_parent) { TMPFS_NODE_LOCK(node); if (node->tn_dir.tn_parent) d_ino = node->tn_dir.tn_parent->tn_id; else d_ino = tmp->tm_root->tn_id; TMPFS_NODE_UNLOCK(node); } else { d_ino = tmp->tm_root->tn_id; } if (vop_write_dirent(&error, uio, d_ino, DT_DIR, 2, "..")) return -1; if (error == 0) { struct tmpfs_dirent *de; de = RB_MIN(tmpfs_dirtree_cookie, &node->tn_dir.tn_cookietree); if (de == NULL) uio->uio_offset = TMPFS_DIRCOOKIE_EOF; else uio->uio_offset = tmpfs_dircookie(de); } return error; } /* --------------------------------------------------------------------- */ /* * Lookup a directory entry by its associated cookie. * * Must be called with the directory node locked (shared ok) */ #if 0 struct lubycookie_info { off_t cookie; struct tmpfs_dirent *de; }; static int lubycookie_cmp(struct tmpfs_dirent *de, void *arg) { struct lubycookie_info *info = arg; off_t cookie = tmpfs_dircookie(de); if (cookie < info->cookie) return(-1); if (cookie > info->cookie) return(1); return(0); } static int lubycookie_callback(struct tmpfs_dirent *de, void *arg) { struct lubycookie_info *info = arg; if (tmpfs_dircookie(de) == info->cookie) { info->de = de; return(-1); } return(0); } #endif /* * Find first cookie >= (cookie). If exact specified, find the exact * cookie. */ struct tmpfs_dirent * tmpfs_dir_lookupbycookie(struct tmpfs_node *node, off_t cookie, int exact) { #if 0 struct lubycookie_info info; info.cookie = cookie; info.de = NULL; RB_SCAN(tmpfs_dirtree_cookie, &node->tn_dir.tn_cookietree, lubycookie_cmp, lubycookie_callback, &info); return (info.de); #endif struct tmpfs_dirent *cdent = tmpfs_cookiedir(cookie); struct tmpfs_dirent *last; struct tmpfs_dirent *tmp; last = NULL; tmp = RB_ROOT(&node->tn_dir.tn_cookietree); while (tmp) { if (cdent == tmp) return cdent; if (cdent > tmp) { last = tmp; tmp = RB_RIGHT(tmp, rb_cookienode); } else { tmp = RB_LEFT(tmp, rb_cookienode); } } return (exact ? NULL : last); } /* --------------------------------------------------------------------- */ /* * 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. * * Caller must hold the node locked (shared ok) */ 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. * * If a particular cookie does not exist, locate the first valid * cookie after that one. */ startcookie = uio->uio_offset; KKASSERT(startcookie != TMPFS_DIRCOOKIE_DOT); KKASSERT(startcookie != TMPFS_DIRCOOKIE_DOTDOT); if (startcookie == TMPFS_DIRCOOKIE_EOF) return 0; /* * Inexact lookup, find first direntry with a cookie >= startcookie. * If none found we are at the EOF. */ de = tmpfs_dir_lookupbycookie(node, startcookie, 0); if (de == NULL) { uio->uio_offset = TMPFS_DIRCOOKIE_EOF; return 0; } /* * Read as much entries as possible; i.e., until we reach the end of * the directory or we exhaust uio space. */ do { ino_t d_ino; uint8_t d_type; /* Create a dirent structure representing the current * tmpfs_node and fill it. */ d_ino = de->td_node->tn_id; switch (de->td_node->tn_type) { case VBLK: d_type = DT_BLK; break; case VCHR: d_type = DT_CHR; break; case VDIR: d_type = DT_DIR; break; case VFIFO: d_type = DT_FIFO; break; case VLNK: d_type = DT_LNK; break; case VREG: d_type = DT_REG; break; case VSOCK: d_type = DT_SOCK; break; default: panic("tmpfs_dir_getdents: type %p %d", de->td_node, (int)de->td_node->tn_type); } KKASSERT(de->td_namelen < 256); /* 255 + 1 */ if (vop_write_dirent(&error, uio, d_ino, d_type, de->td_namelen, de->td_name)) { error = -1; break; } (*cntp)++; de = RB_NEXT(tmpfs_dirtree_cookie, node->tn_dir.tn_cookietree, de); } while (error == 0 && uio->uio_resid > 0 && de != NULL); /* Update the offset and cache. */ if (de == NULL) { uio->uio_offset = TMPFS_DIRCOOKIE_EOF; } else { uio->uio_offset = tmpfs_dircookie(de); } return error; } /* --------------------------------------------------------------------- */ /* * Resizes the aobj associated to 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. * * pass NVEXTF_TRIVIAL when buf content will be overwritten, otherwise set 0 * to be zero filled. * * Returns zero on success or an appropriate error code on failure. * * Caller must hold the node exclusively locked. */ int tmpfs_reg_resize(struct vnode *vp, off_t newsize, int trivial) { int error; vm_pindex_t newpages, oldpages; struct tmpfs_mount *tmp; struct tmpfs_node *node; off_t oldsize; int nvextflags; #ifdef INVARIANTS KKASSERT(vp->v_type == VREG); KKASSERT(newsize >= 0); #endif node = VP_TO_TMPFS_NODE(vp); 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 = round_page64(oldsize) / PAGE_SIZE; KKASSERT(oldpages == node->tn_reg.tn_aobj_pages); newpages = round_page64(newsize) / PAGE_SIZE; if (newpages > oldpages && tmp->tm_pages_used + newpages - oldpages > tmp->tm_pages_max) { error = ENOSPC; goto out; } node->tn_reg.tn_aobj_pages = newpages; node->tn_size = newsize; if (newpages != oldpages) atomic_add_long(&tmp->tm_pages_used, (newpages - oldpages)); /* * nvextflags to pass along for bdwrite() vs buwrite(), this is * so tmpfs activity doesn't eat memory being freed by the pageout * daemon. */ if (vm_pages_needed || vm_paging_start(0) || tmpfs_bufcache_mode >= 2) { nvextflags = 0; } else { nvextflags = NVEXTF_BUWRITE; } /* * When adjusting the vnode filesize and its VM object we must * also adjust our backing VM object (aobj). The blocksize * used must match the block sized we use for the buffer cache. * * The backing VM object may contain VM pages as well as swap * assignments if we previously renamed main object pages into * it during deactivation. * * To make things easier tmpfs uses a blksize in multiples of * PAGE_SIZE, and will only increase the blksize as a small file * increases in size. Once a file has exceeded TMPFS_BLKSIZE (16KB), * the blksize is maxed out. Truncating the file does not reduce * the blksize. */ if (newsize < oldsize) { vm_pindex_t osize; vm_pindex_t nsize; vm_object_t aobj; error = nvtruncbuf(vp, newsize, node->tn_blksize, -1, nvextflags); aobj = node->tn_reg.tn_aobj; if (aobj) { osize = aobj->size; nsize = vp->v_object->size; if (nsize < osize) { aobj->size = osize; swap_pager_freespace(aobj, nsize, osize - nsize); vm_object_page_remove(aobj, nsize, osize, FALSE); } } } else { vm_object_t aobj; int nblksize; /* * The first (and only the first) buffer in the file is resized * in multiples of PAGE_SIZE, up to TMPFS_BLKSIZE. */ nblksize = node->tn_blksize; while (nblksize < TMPFS_BLKSIZE && nblksize < newsize) { nblksize += PAGE_SIZE; } if (trivial) nvextflags |= NVEXTF_TRIVIAL; error = nvextendbuf(vp, oldsize, newsize, node->tn_blksize, nblksize, -1, -1, nvextflags); node->tn_blksize = nblksize; aobj = node->tn_reg.tn_aobj; if (aobj) aobj->size = vp->v_object->size; } out: return error; } /* --------------------------------------------------------------------- */ /* * 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, u_long vaflags, struct ucred *cred) { int error; struct tmpfs_node *node; int flags; KKASSERT(vn_islocked(vp)); node = VP_TO_TMPFS_NODE(vp); flags = node->tn_flags; /* Disallow this operation if the file system is mounted read-only. */ if (vp->v_mount->mnt_flag & MNT_RDONLY) return EROFS; error = vop_helper_setattr_flags(&flags, vaflags, node->tn_uid, cred); /* Actually change the flags on the node itself */ if (error == 0) { TMPFS_NODE_LOCK(node); node->tn_flags = flags; node->tn_status |= TMPFS_NODE_CHANGED; TMPFS_NODE_UNLOCK(node); } KKASSERT(vn_islocked(vp)); return error; } /* --------------------------------------------------------------------- */ /* * 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 vamode, struct ucred *cred) { struct tmpfs_node *node; mode_t cur_mode; int error; KKASSERT(vn_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; cur_mode = node->tn_mode; error = vop_helper_chmod(vp, vamode, cred, node->tn_uid, node->tn_gid, &cur_mode); if (error == 0 && (node->tn_mode & ALLPERMS) != (cur_mode & ALLPERMS)) { TMPFS_NODE_LOCK(node); node->tn_mode &= ~ALLPERMS; node->tn_mode |= cur_mode & ALLPERMS; node->tn_status |= TMPFS_NODE_CHANGED; TMPFS_NODE_UNLOCK(node); } KKASSERT(vn_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) { mode_t cur_mode; uid_t cur_uid; gid_t cur_gid; struct tmpfs_node *node; int error; KKASSERT(vn_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; cur_uid = node->tn_uid; cur_gid = node->tn_gid; cur_mode = node->tn_mode; error = vop_helper_chown(vp, uid, gid, cred, &cur_uid, &cur_gid, &cur_mode); if (error == 0) { TMPFS_NODE_LOCK(node); if (cur_uid != node->tn_uid || cur_gid != node->tn_gid || cur_mode != node->tn_mode) { node->tn_uid = cur_uid; node->tn_gid = cur_gid; node->tn_mode = cur_mode; node->tn_status |= TMPFS_NODE_CHANGED; } TMPFS_NODE_UNLOCK(node); } return error; } /* --------------------------------------------------------------------- */ /* * 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) { int error; struct tmpfs_node *node; KKASSERT(vn_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. */ KKASSERT(vn_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, int vaflags, struct ucred *cred) { struct tmpfs_node *node; KKASSERT(vn_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; TMPFS_NODE_LOCK(node); 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; vclrflags(vp, VLASTWRITETS); } TMPFS_NODE_UNLOCK(node); tmpfs_itimes(vp, atime, mtime); KKASSERT(vn_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); TMPFS_NODE_LOCK(node); if (node->tn_status & TMPFS_NODE_ACCESSED) { if (acc == NULL) acc = &now; node->tn_atime = acc->tv_sec; node->tn_atimensec = acc->tv_nsec; } if (node->tn_status & TMPFS_NODE_MODIFIED) { if (mod == NULL) mod = &now; node->tn_mtime = mod->tv_sec; node->tn_mtimensec = mod->tv_nsec; } if (node->tn_status & TMPFS_NODE_CHANGED) { node->tn_ctime = now.tv_sec; node->tn_ctimensec = now.tv_nsec; } node->tn_status &= ~(TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED); TMPFS_NODE_UNLOCK(node); } /* --------------------------------------------------------------------- */ void tmpfs_update(struct vnode *vp) { tmpfs_itimes(vp, NULL, NULL); } /* --------------------------------------------------------------------- */ /* * Caller must hold an exclusive node lock. */ 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, 1); if (error == 0) node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED; out: tmpfs_update(vp); return error; } /* --------------------------------------------------------------------- */ static ino_t tmpfs_fetch_ino(struct tmpfs_mount *tmp) { ino_t ret; ret = atomic_fetchadd_64(&tmp->tm_ino, 1); return (ret); } static int tmpfs_dirtree_compare(struct tmpfs_dirent *a, struct tmpfs_dirent *b) { if (a->td_namelen > b->td_namelen) return 1; else if (a->td_namelen < b->td_namelen) return -1; else return strncmp(a->td_name, b->td_name, a->td_namelen); } static int tmpfs_dirtree_compare_cookie(struct tmpfs_dirent *a, struct tmpfs_dirent *b) { if (a < b) return(-1); if (a > b) return(1); return 0; } /* * Lock for rename. The namecache entries for the related terminal files * are already locked but the directories are not. A directory lock order * reversal is possible so use a deterministic order. * * Generally order path parent-to-child or using a simple pointer comparison. * Probably not perfect but it should catch most of the cases. * * Underlying files must be locked after the related directory. */ void tmpfs_lock4(struct tmpfs_node *node1, struct tmpfs_node *node2, struct tmpfs_node *node3, struct tmpfs_node *node4) { if (node1->tn_dir.tn_parent != node2 && (node1 < node2 || node2->tn_dir.tn_parent == node1)) { TMPFS_NODE_LOCK(node1); /* fdir */ TMPFS_NODE_LOCK(node3); /* ffile */ TMPFS_NODE_LOCK(node2); /* tdir */ if (node4) TMPFS_NODE_LOCK(node4); /* tfile */ } else { TMPFS_NODE_LOCK(node2); /* tdir */ if (node4) TMPFS_NODE_LOCK(node4); /* tfile */ TMPFS_NODE_LOCK(node1); /* fdir */ TMPFS_NODE_LOCK(node3); /* ffile */ } } void tmpfs_unlock4(struct tmpfs_node *node1, struct tmpfs_node *node2, struct tmpfs_node *node3, struct tmpfs_node *node4) { if (node4) TMPFS_NODE_UNLOCK(node4); TMPFS_NODE_UNLOCK(node2); TMPFS_NODE_UNLOCK(node3); TMPFS_NODE_UNLOCK(node1); }