diff options
Diffstat (limited to 'sys/fs/tmpfs/tmpfs_subr.c')
| -rw-r--r-- | sys/fs/tmpfs/tmpfs_subr.c | 1736 |
1 files changed, 1736 insertions, 0 deletions
diff --git a/sys/fs/tmpfs/tmpfs_subr.c b/sys/fs/tmpfs/tmpfs_subr.c new file mode 100644 index 0000000..4739f85 --- /dev/null +++ b/sys/fs/tmpfs/tmpfs_subr.c @@ -0,0 +1,1736 @@ +/* $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 <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/fnv_hash.h> +#include <sys/lock.h> +#include <sys/namei.h> +#include <sys/priv.h> +#include <sys/proc.h> +#include <sys/rwlock.h> +#include <sys/stat.h> +#include <sys/systm.h> +#include <sys/sysctl.h> +#include <sys/vnode.h> +#include <sys/vmmeter.h> + +#include <vm/vm.h> +#include <vm/vm_param.h> +#include <vm/vm_object.h> +#include <vm/vm_page.h> +#include <vm/vm_pageout.h> +#include <vm/vm_pager.h> +#include <vm/vm_extern.h> + +#include <fs/tmpfs/tmpfs.h> +#include <fs/tmpfs/tmpfs_fifoops.h> +#include <fs/tmpfs/tmpfs_vnops.h> + +struct tmpfs_dir_cursor { + struct tmpfs_dirent *tdc_current; + struct tmpfs_dirent *tdc_tree; +}; + +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"); + +static __inline int tmpfs_dirtree_cmp(struct tmpfs_dirent *a, + struct tmpfs_dirent *b); +RB_PROTOTYPE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp); + +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: + RB_INIT(&nnode->tn_dir.tn_dirhead); + LIST_INIT(&nnode->tn_dir.tn_dupindex); + 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); +} + +/* --------------------------------------------------------------------- */ + +static __inline uint32_t +tmpfs_dirent_hash(const char *name, u_int len) +{ + uint32_t hash; + + hash = fnv_32_buf(name, len, FNV1_32_INIT + len) & TMPFS_DIRCOOKIE_MASK; +#ifdef TMPFS_DEBUG_DIRCOOKIE_DUP + hash &= 0xf; +#endif + if (hash < TMPFS_DIRCOOKIE_MIN) + hash += TMPFS_DIRCOOKIE_MIN; + + return (hash); +} + +static __inline off_t +tmpfs_dirent_cookie(struct tmpfs_dirent *de) +{ + MPASS(de->td_cookie >= TMPFS_DIRCOOKIE_MIN); + + return (de->td_cookie); +} + +static __inline boolean_t +tmpfs_dirent_dup(struct tmpfs_dirent *de) +{ + return ((de->td_cookie & TMPFS_DIRCOOKIE_DUP) != 0); +} + +static __inline boolean_t +tmpfs_dirent_duphead(struct tmpfs_dirent *de) +{ + return ((de->td_cookie & TMPFS_DIRCOOKIE_DUPHEAD) != 0); +} + +void +tmpfs_dirent_init(struct tmpfs_dirent *de, const char *name, u_int namelen) +{ + de->td_hash = de->td_cookie = tmpfs_dirent_hash(name, namelen); + memcpy(de->ud.td_name, name, namelen); + de->td_namelen = namelen; +} + +/* + * 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, u_int len, struct tmpfs_dirent **de) +{ + struct tmpfs_dirent *nde; + + nde = uma_zalloc(tmp->tm_dirent_pool, M_WAITOK); + nde->td_node = node; + if (name != NULL) { + nde->ud.td_name = malloc(len, M_TMPFSNAME, M_WAITOK); + tmpfs_dirent_init(nde, name, len); + } else + nde->td_namelen = 0; + 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) +{ + struct tmpfs_node *node; + + node = de->td_node; + if (node != NULL) { + MPASS(node->tn_links > 0); + node->tn_links--; + } + if (!tmpfs_dirent_duphead(de) && de->ud.td_name != NULL) + free(de->ud.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); + 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; +} + +/* --------------------------------------------------------------------- */ + +static struct tmpfs_dirent * +tmpfs_dir_first(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc) +{ + struct tmpfs_dirent *de; + + de = RB_MIN(tmpfs_dir, &dnode->tn_dir.tn_dirhead); + dc->tdc_tree = de; + if (de != NULL && tmpfs_dirent_duphead(de)) + de = LIST_FIRST(&de->ud.td_duphead); + dc->tdc_current = de; + + return (dc->tdc_current); +} + +static struct tmpfs_dirent * +tmpfs_dir_next(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc) +{ + struct tmpfs_dirent *de; + + MPASS(dc->tdc_tree != NULL); + if (tmpfs_dirent_dup(dc->tdc_current)) { + dc->tdc_current = LIST_NEXT(dc->tdc_current, uh.td_dup.entries); + if (dc->tdc_current != NULL) + return (dc->tdc_current); + } + dc->tdc_tree = dc->tdc_current = RB_NEXT(tmpfs_dir, + &dnode->tn_dir.tn_dirhead, dc->tdc_tree); + if ((de = dc->tdc_current) != NULL && tmpfs_dirent_duphead(de)) { + dc->tdc_current = LIST_FIRST(&de->ud.td_duphead); + MPASS(dc->tdc_current != NULL); + } + + return (dc->tdc_current); +} + +/* Lookup directory entry in RB-Tree. Function may return duphead entry. */ +static struct tmpfs_dirent * +tmpfs_dir_xlookup_hash(struct tmpfs_node *dnode, uint32_t hash) +{ + struct tmpfs_dirent *de, dekey; + + dekey.td_hash = hash; + de = RB_FIND(tmpfs_dir, &dnode->tn_dir.tn_dirhead, &dekey); + return (de); +} + +/* Lookup directory entry by cookie, initialize directory cursor accordingly. */ +static struct tmpfs_dirent * +tmpfs_dir_lookup_cookie(struct tmpfs_node *node, off_t cookie, + struct tmpfs_dir_cursor *dc) +{ + struct tmpfs_dir *dirhead = &node->tn_dir.tn_dirhead; + struct tmpfs_dirent *de, dekey; + + MPASS(cookie >= TMPFS_DIRCOOKIE_MIN); + + if (cookie == node->tn_dir.tn_readdir_lastn && + (de = node->tn_dir.tn_readdir_lastp) != NULL) { + /* Protect against possible race, tn_readdir_last[pn] + * may be updated with only shared vnode lock held. */ + if (cookie == tmpfs_dirent_cookie(de)) + goto out; + } + + if ((cookie & TMPFS_DIRCOOKIE_DUP) != 0) { + LIST_FOREACH(de, &node->tn_dir.tn_dupindex, + uh.td_dup.index_entries) { + MPASS(tmpfs_dirent_dup(de)); + if (de->td_cookie == cookie) + goto out; + /* dupindex list is sorted. */ + if (de->td_cookie < cookie) { + de = NULL; + goto out; + } + } + MPASS(de == NULL); + goto out; + } + + MPASS((cookie & TMPFS_DIRCOOKIE_MASK) == cookie); + dekey.td_hash = cookie; + /* Recover if direntry for cookie was removed */ + de = RB_NFIND(tmpfs_dir, dirhead, &dekey); + dc->tdc_tree = de; + dc->tdc_current = de; + if (de != NULL && tmpfs_dirent_duphead(de)) { + dc->tdc_current = LIST_FIRST(&de->ud.td_duphead); + MPASS(dc->tdc_current != NULL); + } + return (dc->tdc_current); + +out: + dc->tdc_tree = de; + dc->tdc_current = de; + if (de != NULL && tmpfs_dirent_dup(de)) + dc->tdc_tree = tmpfs_dir_xlookup_hash(node, + de->td_hash); + return (dc->tdc_current); +} + +/* + * 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) +{ + struct tmpfs_dir_duphead *duphead; + struct tmpfs_dirent *de; + uint32_t hash; + + 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); + + hash = tmpfs_dirent_hash(cnp->cn_nameptr, cnp->cn_namelen); + de = tmpfs_dir_xlookup_hash(node, hash); + if (de != NULL && tmpfs_dirent_duphead(de)) { + duphead = &de->ud.td_duphead; + LIST_FOREACH(de, duphead, uh.td_dup.entries) { + if (TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr, + cnp->cn_namelen)) + break; + } + } else if (de != NULL) { + if (!TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr, + cnp->cn_namelen)) + de = NULL; + } + if (de != NULL && f != NULL && de->td_node != f) + de = NULL; + + return (de); +} + +/* + * Attach duplicate-cookie directory entry nde to dnode and insert to dupindex + * list, allocate new cookie value. + */ +static void +tmpfs_dir_attach_dup(struct tmpfs_node *dnode, + struct tmpfs_dir_duphead *duphead, struct tmpfs_dirent *nde) +{ + struct tmpfs_dir_duphead *dupindex; + struct tmpfs_dirent *de, *pde; + + dupindex = &dnode->tn_dir.tn_dupindex; + de = LIST_FIRST(dupindex); + if (de == NULL || de->td_cookie < TMPFS_DIRCOOKIE_DUP_MAX) { + if (de == NULL) + nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN; + else + nde->td_cookie = de->td_cookie + 1; + MPASS(tmpfs_dirent_dup(nde)); + LIST_INSERT_HEAD(dupindex, nde, uh.td_dup.index_entries); + LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); + return; + } + + /* + * Cookie numbers are near exhaustion. Scan dupindex list for unused + * numbers. dupindex list is sorted in descending order. Keep it so + * after inserting nde. + */ + while (1) { + pde = de; + de = LIST_NEXT(de, uh.td_dup.index_entries); + if (de == NULL && pde->td_cookie != TMPFS_DIRCOOKIE_DUP_MIN) { + /* + * Last element of the index doesn't have minimal cookie + * value, use it. + */ + nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN; + LIST_INSERT_AFTER(pde, nde, uh.td_dup.index_entries); + LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); + return; + } else if (de == NULL) { + /* + * We are so lucky have 2^30 hash duplicates in single + * directory :) Return largest possible cookie value. + * It should be fine except possible issues with + * VOP_READDIR restart. + */ + nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MAX; + LIST_INSERT_HEAD(dupindex, nde, + uh.td_dup.index_entries); + LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); + return; + } + if (de->td_cookie + 1 == pde->td_cookie || + de->td_cookie >= TMPFS_DIRCOOKIE_DUP_MAX) + continue; /* No hole or invalid cookie. */ + nde->td_cookie = de->td_cookie + 1; + MPASS(tmpfs_dirent_dup(nde)); + MPASS(pde->td_cookie > nde->td_cookie); + MPASS(nde->td_cookie > de->td_cookie); + LIST_INSERT_BEFORE(de, nde, uh.td_dup.index_entries); + LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries); + return; + }; +} + +/* + * 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; + struct tmpfs_dirent *xde, *nde; + + ASSERT_VOP_ELOCKED(vp, __func__); + MPASS(de->td_namelen > 0); + MPASS(de->td_hash >= TMPFS_DIRCOOKIE_MIN); + MPASS(de->td_cookie == de->td_hash); + + dnode = VP_TO_TMPFS_DIR(vp); + dnode->tn_dir.tn_readdir_lastn = 0; + dnode->tn_dir.tn_readdir_lastp = NULL; + + MPASS(!tmpfs_dirent_dup(de)); + xde = RB_INSERT(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de); + if (xde != NULL && tmpfs_dirent_duphead(xde)) + tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de); + else if (xde != NULL) { + /* + * Allocate new duphead. Swap xde with duphead to avoid + * adding/removing elements with the same hash. + */ + MPASS(!tmpfs_dirent_dup(xde)); + tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount), NULL, NULL, 0, + &nde); + /* *nde = *xde; XXX gcc 4.2.1 may generate invalid code. */ + memcpy(nde, xde, sizeof(*xde)); + xde->td_cookie |= TMPFS_DIRCOOKIE_DUPHEAD; + LIST_INIT(&xde->ud.td_duphead); + xde->td_namelen = 0; + xde->td_node = NULL; + tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, nde); + tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de); + } + 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_mount *tmp; + struct tmpfs_dir *head; + struct tmpfs_node *dnode; + struct tmpfs_dirent *xde; + + ASSERT_VOP_ELOCKED(vp, __func__); + + dnode = VP_TO_TMPFS_DIR(vp); + head = &dnode->tn_dir.tn_dirhead; + dnode->tn_dir.tn_readdir_lastn = 0; + dnode->tn_dir.tn_readdir_lastp = NULL; + + if (tmpfs_dirent_dup(de)) { + /* Remove duphead if de was last entry. */ + if (LIST_NEXT(de, uh.td_dup.entries) == NULL) { + xde = tmpfs_dir_xlookup_hash(dnode, de->td_hash); + MPASS(tmpfs_dirent_duphead(xde)); + } else + xde = NULL; + LIST_REMOVE(de, uh.td_dup.entries); + LIST_REMOVE(de, uh.td_dup.index_entries); + if (xde != NULL) { + if (LIST_EMPTY(&xde->ud.td_duphead)) { + RB_REMOVE(tmpfs_dir, head, xde); + tmp = VFS_TO_TMPFS(vp->v_mount); + MPASS(xde->td_node == NULL); + tmpfs_free_dirent(tmp, xde); + } + } + } else + RB_REMOVE(tmpfs_dir, head, de); + + dnode->tn_size -= sizeof(struct tmpfs_dirent); + dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \ + TMPFS_NODE_MODIFIED; +} + +void +tmpfs_dir_destroy(struct tmpfs_mount *tmp, struct tmpfs_node *dnode) +{ + struct tmpfs_dirent *de, *dde, *nde; + + RB_FOREACH_SAFE(de, tmpfs_dir, &dnode->tn_dir.tn_dirhead, nde) { + RB_REMOVE(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de); + /* Node may already be destroyed. */ + de->td_node = NULL; + if (tmpfs_dirent_duphead(de)) { + while ((dde = LIST_FIRST(&de->ud.td_duphead)) != NULL) { + LIST_REMOVE(dde, uh.td_dup.entries); + dde->td_node = NULL; + tmpfs_free_dirent(tmp, dde); + } + } + tmpfs_free_dirent(tmp, 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. + */ +static 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 = EJUSTRETURN; + else + error = uiomove(&dent, dent.d_reclen, uio); + + 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. + */ +static 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 = EJUSTRETURN; + else + error = uiomove(&dent, dent.d_reclen, uio); + + node->tn_status |= TMPFS_NODE_ACCESSED; + + return error; +} + +/* --------------------------------------------------------------------- */ + +/* + * 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, int cnt, + u_long *cookies, int *ncookies) +{ + struct tmpfs_dir_cursor dc; + struct tmpfs_dirent *de; + off_t off; + int error; + + TMPFS_VALIDATE_DIR(node); + + off = 0; + switch (uio->uio_offset) { + case TMPFS_DIRCOOKIE_DOT: + error = tmpfs_dir_getdotdent(node, uio); + if (error != 0) + return (error); + uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT; + if (cnt != 0) + cookies[(*ncookies)++] = off = uio->uio_offset; + case TMPFS_DIRCOOKIE_DOTDOT: + error = tmpfs_dir_getdotdotdent(node, uio); + if (error != 0) + return (error); + de = tmpfs_dir_first(node, &dc); + if (de == NULL) + uio->uio_offset = TMPFS_DIRCOOKIE_EOF; + else + uio->uio_offset = tmpfs_dirent_cookie(de); + if (cnt != 0) + cookies[(*ncookies)++] = off = uio->uio_offset; + if (de == NULL) + return (0); + break; + case TMPFS_DIRCOOKIE_EOF: + return (0); + default: + de = tmpfs_dir_lookup_cookie(node, uio->uio_offset, &dc); + if (de == NULL) + return (EINVAL); + if (cnt != 0) + off = tmpfs_dirent_cookie(de); + } + + /* 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->ud.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 = EJUSTRETURN; + break; + } + + /* Copy the new dirent structure into the output buffer and + * advance pointers. */ + error = uiomove(&d, d.d_reclen, uio); + if (error == 0) { + de = tmpfs_dir_next(node, &dc); + if (cnt != 0) { + if (de == NULL) + off = TMPFS_DIRCOOKIE_EOF; + else + off = tmpfs_dirent_cookie(de); + MPASS(*ncookies < cnt); + cookies[(*ncookies)++] = off; + } + } + } while (error == 0 && uio->uio_resid > 0 && de != NULL); + + /* Update the offset and cache. */ + if (cnt == 0) { + if (de == NULL) + off = TMPFS_DIRCOOKIE_EOF; + else + off = tmpfs_dirent_cookie(de); + } + + uio->uio_offset = off; + node->tn_dir.tn_readdir_lastn = off; + 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); +} + +/* --------------------------------------------------------------------- */ + +/* + * 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_WLOCK(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_WUNLOCK(uobj); + VM_WAIT; + VM_OBJECT_WLOCK(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_WUNLOCK(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_WUNLOCK(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, u_long flags, struct ucred *cred, + struct thread *p) +{ + int error; + struct tmpfs_node *node; + + MPASS(VOP_ISLOCKED(vp)); + + node = VP_TO_TMPFS_NODE(vp); + + if ((flags & ~(UF_NODUMP | UF_IMMUTABLE | UF_APPEND | UF_OPAQUE | + UF_NOUNLINK | SF_ARCHIVED | SF_IMMUTABLE | SF_APPEND | + SF_NOUNLINK)) != 0) + return (EOPNOTSUPP); + + /* 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); + } + } else { + if (node->tn_flags & + (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) || + ((flags ^ node->tn_flags) & SF_SETTABLE)) + return (EPERM); + } + node->tn_flags = flags; + 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; +} + +static __inline int +tmpfs_dirtree_cmp(struct tmpfs_dirent *a, struct tmpfs_dirent *b) +{ + if (a->td_hash > b->td_hash) + return (1); + else if (a->td_hash < b->td_hash) + return (-1); + return (0); +} + +RB_GENERATE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp); |
