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freebsd-dev/sys/fs/tmpfs/tmpfs_subr.c

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/* $NetBSD: tmpfs_subr.c,v 1.35 2007/07/09 21:10:50 ad Exp $ */
/*-
* SPDX-License-Identifier: BSD-2-Clause-NetBSD
*
* 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/systm.h>
#include <sys/dirent.h>
#include <sys/fnv_hash.h>
#include <sys/lock.h>
#include <sys/limits.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/random.h>
#include <sys/refcount.h>
#include <sys/rwlock.h>
#include <sys/smr.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/user.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 <vm/swap_pager.h>
#include <fs/tmpfs/tmpfs.h>
#include <fs/tmpfs/tmpfs_fifoops.h>
#include <fs/tmpfs/tmpfs_vnops.h>
SYSCTL_NODE(_vfs, OID_AUTO, tmpfs, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"tmpfs file system");
static long tmpfs_pages_reserved = TMPFS_PAGES_MINRESERVED;
MALLOC_DEFINE(M_TMPFSDIR, "tmpfs dir", "tmpfs dirent structure");
static uma_zone_t tmpfs_node_pool;
VFS_SMR_DECLARE;
int tmpfs_pager_type = -1;
static vm_object_t
tmpfs_pager_alloc(void *handle, vm_ooffset_t size, vm_prot_t prot,
vm_ooffset_t offset, struct ucred *cred)
{
vm_object_t object;
MPASS(handle == NULL);
MPASS(offset == 0);
object = vm_object_allocate_dyn(tmpfs_pager_type, size,
OBJ_COLORED | OBJ_SWAP);
if (!swap_pager_init_object(object, NULL, NULL, size, 0)) {
vm_object_deallocate(object);
object = NULL;
}
return (object);
}
/*
* Make sure tmpfs vnodes with writable mappings can be found on the lazy list.
*
* This allows for periodic mtime updates while only scanning vnodes which are
* plausibly dirty, see tmpfs_update_mtime_lazy.
*/
static void
tmpfs_pager_writecount_recalc(vm_object_t object, vm_offset_t old,
vm_offset_t new)
{
struct vnode *vp;
VM_OBJECT_ASSERT_WLOCKED(object);
vp = object->un_pager.swp.swp_tmpfs;
/*
* Forced unmount?
*/
if (vp == NULL) {
KASSERT((object->flags & OBJ_TMPFS_VREF) == 0,
("object %p with OBJ_TMPFS_VREF but without vnode", object));
VM_OBJECT_WUNLOCK(object);
return;
}
if (old == 0) {
VNASSERT((object->flags & OBJ_TMPFS_VREF) == 0, vp,
("object without writable mappings has a reference"));
VNPASS(vp->v_usecount > 0, vp);
} else {
VNASSERT((object->flags & OBJ_TMPFS_VREF) != 0, vp,
("object with writable mappings does not have a reference"));
}
if (old == new) {
VM_OBJECT_WUNLOCK(object);
return;
}
if (new == 0) {
vm_object_clear_flag(object, OBJ_TMPFS_VREF);
VM_OBJECT_WUNLOCK(object);
vrele(vp);
} else {
if ((object->flags & OBJ_TMPFS_VREF) == 0) {
vref(vp);
vlazy(vp);
vm_object_set_flag(object, OBJ_TMPFS_VREF);
}
VM_OBJECT_WUNLOCK(object);
}
}
static void
tmpfs_pager_update_writecount(vm_object_t object, vm_offset_t start,
vm_offset_t end)
{
vm_offset_t new, old;
VM_OBJECT_WLOCK(object);
KASSERT((object->flags & OBJ_ANON) == 0,
("%s: object %p with OBJ_ANON", __func__, object));
old = object->un_pager.swp.writemappings;
object->un_pager.swp.writemappings += (vm_ooffset_t)end - start;
new = object->un_pager.swp.writemappings;
tmpfs_pager_writecount_recalc(object, old, new);
VM_OBJECT_ASSERT_UNLOCKED(object);
}
static void
tmpfs_pager_release_writecount(vm_object_t object, vm_offset_t start,
vm_offset_t end)
{
vm_offset_t new, old;
VM_OBJECT_WLOCK(object);
KASSERT((object->flags & OBJ_ANON) == 0,
("%s: object %p with OBJ_ANON", __func__, object));
old = object->un_pager.swp.writemappings;
object->un_pager.swp.writemappings -= (vm_ooffset_t)end - start;
new = object->un_pager.swp.writemappings;
tmpfs_pager_writecount_recalc(object, old, new);
VM_OBJECT_ASSERT_UNLOCKED(object);
}
static void
tmpfs_pager_getvp(vm_object_t object, struct vnode **vpp, bool *vp_heldp)
{
struct vnode *vp;
/*
* Tmpfs VREG node, which was reclaimed, has tmpfs_pager_type
* type, but not OBJ_TMPFS flag. In this case there is no
* v_writecount to adjust.
*/
if (vp_heldp != NULL)
VM_OBJECT_RLOCK(object);
else
VM_OBJECT_ASSERT_LOCKED(object);
if ((object->flags & OBJ_TMPFS) != 0) {
vp = object->un_pager.swp.swp_tmpfs;
if (vp != NULL) {
*vpp = vp;
if (vp_heldp != NULL) {
vhold(vp);
*vp_heldp = true;
}
}
}
if (vp_heldp != NULL)
VM_OBJECT_RUNLOCK(object);
}
struct pagerops tmpfs_pager_ops = {
.pgo_kvme_type = KVME_TYPE_VNODE,
.pgo_alloc = tmpfs_pager_alloc,
.pgo_set_writeable_dirty = vm_object_set_writeable_dirty_,
.pgo_update_writecount = tmpfs_pager_update_writecount,
.pgo_release_writecount = tmpfs_pager_release_writecount,
.pgo_mightbedirty = vm_object_mightbedirty_,
.pgo_getvp = tmpfs_pager_getvp,
};
static int
tmpfs_node_ctor(void *mem, int size, void *arg, int flags)
{
struct tmpfs_node *node;
node = mem;
node->tn_gen++;
node->tn_size = 0;
node->tn_status = 0;
node->tn_accessed = false;
node->tn_flags = 0;
node->tn_links = 0;
node->tn_vnode = NULL;
node->tn_vpstate = 0;
return (0);
}
static void
tmpfs_node_dtor(void *mem, int size, void *arg)
{
struct tmpfs_node *node;
node = mem;
node->tn_type = VNON;
}
static int
tmpfs_node_init(void *mem, int size, int flags)
{
struct tmpfs_node *node;
node = mem;
node->tn_id = 0;
mtx_init(&node->tn_interlock, "tmpfsni", NULL, MTX_DEF);
node->tn_gen = arc4random();
return (0);
}
static void
tmpfs_node_fini(void *mem, int size)
{
struct tmpfs_node *node;
node = mem;
mtx_destroy(&node->tn_interlock);
}
int
tmpfs_subr_init(void)
{
tmpfs_pager_type = vm_pager_alloc_dyn_type(&tmpfs_pager_ops,
OBJT_SWAP);
if (tmpfs_pager_type == -1)
return (EINVAL);
tmpfs_node_pool = uma_zcreate("TMPFS node",
sizeof(struct tmpfs_node), tmpfs_node_ctor, tmpfs_node_dtor,
tmpfs_node_init, tmpfs_node_fini, UMA_ALIGN_PTR, 0);
VFS_SMR_ZONE_SET(tmpfs_node_pool);
return (0);
}
void
tmpfs_subr_uninit(void)
{
if (tmpfs_pager_type != -1)
vm_pager_free_dyn_type(tmpfs_pager_type);
tmpfs_pager_type = -1;
uma_zdestroy(tmpfs_node_pool);
}
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_MPSAFE|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)
{
size_t avail;
long reserved;
avail = swap_pager_avail + vm_free_count();
reserved = atomic_load_long(&tmpfs_pages_reserved);
if (__predict_false(avail < reserved))
return (0);
return (avail - reserved);
}
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 != ULONG_MAX &&
tmp->tm_pages_max < req_pages + tmpfs_pages_used(tmp))
return (0);
return (1);
}
void
tmpfs_ref_node(struct tmpfs_node *node)
{
#ifdef INVARIANTS
u_int old;
old =
#endif
refcount_acquire(&node->tn_refcount);
#ifdef INVARIANTS
KASSERT(old > 0, ("node %p zero refcount", node));
#endif
}
/*
* 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 mount *mp, struct tmpfs_mount *tmp, enum vtype type,
uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *parent,
const char *target, dev_t rdev, struct tmpfs_node **node)
{
struct tmpfs_node *nnode;
vm_object_t obj;
char *symlink;
char symlink_smr;
/* 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);
if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
/*
* When a new tmpfs node is created for fully
* constructed mount point, there must be a parent
* node, which vnode is locked exclusively. As
* consequence, if the unmount is executing in
* parallel, vflush() cannot reclaim the parent vnode.
* Due to this, the check for MNTK_UNMOUNT flag is not
* racy: if we did not see MNTK_UNMOUNT flag, then tmp
* cannot be destroyed until node construction is
* finished and the parent vnode unlocked.
*
* Tmpfs does not need to instantiate new nodes during
* unmount.
*/
return (EBUSY);
}
if ((mp->mnt_kern_flag & MNT_RDONLY) != 0)
return (EROFS);
nnode = uma_zalloc_smr(tmpfs_node_pool, 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_unr64(&tmp->tm_ino_unr);
nnode->tn_refcount = 1;
/* 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);
symlink = NULL;
if (!tmp->tm_nonc) {
symlink = cache_symlink_alloc(nnode->tn_size + 1, M_WAITOK);
symlink_smr = true;
}
if (symlink == NULL) {
symlink = malloc(nnode->tn_size + 1, M_TMPFSNAME, M_WAITOK);
symlink_smr = false;
}
memcpy(symlink, target, nnode->tn_size + 1);
/*
* Allow safe symlink resolving for lockless lookup.
* tmpfs_fplookup_symlink references this comment.
*
* 1. nnode is not yet visible to the world
* 2. both tn_link_target and tn_link_smr get populated
* 3. release fence publishes their content
* 4. tn_link_target content is immutable until node destruction,
* where the pointer gets set to NULL
* 5. tn_link_smr is never changed once set
*
* As a result it is sufficient to issue load consume on the node
* pointer to also get the above content in a stable manner.
* Worst case tn_link_smr flag may be set to true despite being stale,
* while the target buffer is already cleared out.
*/
atomic_store_ptr(&nnode->tn_link_target, symlink);
atomic_store_char((char *)&nnode->tn_link_smr, symlink_smr);
atomic_thread_fence_rel();
break;
case VREG:
obj = nnode->tn_reg.tn_aobj =
vm_pager_allocate(tmpfs_pager_type, NULL, 0,
VM_PROT_DEFAULT, 0,
NULL /* XXXKIB - tmpfs needs swap reservation */);
/* OBJ_TMPFS is set together with the setting of vp->v_object */
nnode->tn_reg.tn_tmp = tmp;
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);
nnode->tn_attached = true;
tmp->tm_nodes_inuse++;
tmp->tm_refcount++;
TMPFS_UNLOCK(tmp);
*node = nnode;
return (0);
}
/*
* Destroys the node pointed to by node from the file system 'tmp'.
* If the node references a directory, no entries are allowed.
*/
void
tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node)
{
if (refcount_release_if_not_last(&node->tn_refcount))
return;
TMPFS_LOCK(tmp);
TMPFS_NODE_LOCK(node);
if (!tmpfs_free_node_locked(tmp, node, false)) {
TMPFS_NODE_UNLOCK(node);
TMPFS_UNLOCK(tmp);
}
}
bool
tmpfs_free_node_locked(struct tmpfs_mount *tmp, struct tmpfs_node *node,
bool detach)
{
vm_object_t uobj;
char *symlink;
bool last;
TMPFS_MP_ASSERT_LOCKED(tmp);
TMPFS_NODE_ASSERT_LOCKED(node);
last = refcount_release(&node->tn_refcount);
if (node->tn_attached && (detach || last)) {
MPASS(tmp->tm_nodes_inuse > 0);
tmp->tm_nodes_inuse--;
LIST_REMOVE(node, tn_entries);
node->tn_attached = false;
}
if (!last)
return (false);
TMPFS_NODE_UNLOCK(node);
#ifdef INVARIANTS
MPASS(node->tn_vnode == NULL);
MPASS((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0);
/*
* Make sure this is a node type we can deal with. Everything is explicitly
* enumerated without the 'default' clause so the the compiler can throw an
* error in case a new type is added.
*/
switch (node->tn_type) {
case VBLK:
case VCHR:
case VDIR:
case VFIFO:
case VSOCK:
case VLNK:
case VREG:
break;
case VNON:
case VBAD:
case VMARKER:
panic("%s: bad type %d for node %p", __func__, (int)node->tn_type, node);
}
#endif
switch (node->tn_type) {
case VREG:
uobj = node->tn_reg.tn_aobj;
if (uobj != NULL) {
if (uobj->size != 0)
atomic_subtract_long(&tmp->tm_pages_used, uobj->size);
}
tmpfs_free_tmp(tmp);
if (uobj != NULL) {
KASSERT((uobj->flags & OBJ_TMPFS) == 0,
("leaked OBJ_TMPFS node %p vm_obj %p", node, uobj));
vm_object_deallocate(uobj);
}
break;
case VLNK:
tmpfs_free_tmp(tmp);
symlink = node->tn_link_target;
atomic_store_ptr(&node->tn_link_target, NULL);
if (atomic_load_char(&node->tn_link_smr)) {
cache_symlink_free(symlink, node->tn_size + 1);
} else {
free(symlink, M_TMPFSNAME);
}
break;
default:
tmpfs_free_tmp(tmp);
break;
}
uma_zfree_smr(tmpfs_node_pool, node);
return (true);
}
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)
{
if (de == NULL)
return (TMPFS_DIRCOOKIE_EOF);
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 = malloc(sizeof(*nde), M_TMPFSDIR, 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);
free(de, M_TMPFSDIR);
}
void
tmpfs_destroy_vobject(struct vnode *vp, vm_object_t obj)
{
bool want_vrele;
ASSERT_VOP_ELOCKED(vp, "tmpfs_destroy_vobject");
if (vp->v_type != VREG || obj == NULL)
return;
VM_OBJECT_WLOCK(obj);
VI_LOCK(vp);
/*
* May be going through forced unmount.
*/
want_vrele = false;
if ((obj->flags & OBJ_TMPFS_VREF) != 0) {
vm_object_clear_flag(obj, OBJ_TMPFS_VREF);
want_vrele = true;
}
vm_object_clear_flag(obj, OBJ_TMPFS);
obj->un_pager.swp.swp_tmpfs = NULL;
if (vp->v_writecount < 0)
vp->v_writecount = 0;
VI_UNLOCK(vp);
VM_OBJECT_WUNLOCK(obj);
if (want_vrele) {
vrele(vp);
}
}
/*
* Need to clear v_object for insmntque failure.
*/
static void
tmpfs_insmntque_dtr(struct vnode *vp, void *dtr_arg)
{
tmpfs_destroy_vobject(vp, vp->v_object);
vp->v_object = NULL;
vp->v_data = NULL;
vp->v_op = &dead_vnodeops;
vgone(vp);
vput(vp);
}
/*
* 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)
{
struct vnode *vp;
enum vgetstate vs;
struct tmpfs_mount *tm;
vm_object_t object;
int error;
error = 0;
tm = VFS_TO_TMPFS(mp);
TMPFS_NODE_LOCK(node);
tmpfs_ref_node(node);
loop:
TMPFS_NODE_ASSERT_LOCKED(node);
if ((vp = node->tn_vnode) != NULL) {
MPASS((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0);
if ((node->tn_type == VDIR && node->tn_dir.tn_parent == NULL) ||
(VN_IS_DOOMED(vp) &&
(lkflag & LK_NOWAIT) != 0)) {
TMPFS_NODE_UNLOCK(node);
error = ENOENT;
vp = NULL;
goto out;
}
if (VN_IS_DOOMED(vp)) {
node->tn_vpstate |= TMPFS_VNODE_WRECLAIM;
while ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0) {
msleep(&node->tn_vnode, TMPFS_NODE_MTX(node),
0, "tmpfsE", 0);
}
goto loop;
}
vs = vget_prep(vp);
TMPFS_NODE_UNLOCK(node);
error = vget_finish(vp, lkflag, vs);
if (error == ENOENT) {
TMPFS_NODE_LOCK(node);
goto loop;
}
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 != vp) {
vput(vp);
TMPFS_NODE_LOCK(node);
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), 0, "tmpfs_alloc_vp", 0);
if (error != 0)
goto out;
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, VFS_TO_TMPFS(mp)->tm_nonc ?
&tmpfs_vnodeop_nonc_entries : &tmpfs_vnodeop_entries, &vp);
if (error != 0)
goto unlock;
MPASS(vp != NULL);
/* lkflag is ignored, the lock is exclusive */
(void) vn_lock(vp, LK_EXCLUSIVE | 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 VSOCK:
break;
case VFIFO:
vp->v_op = &tmpfs_fifoop_entries;
break;
case VREG:
object = node->tn_reg.tn_aobj;
VM_OBJECT_WLOCK(object);
KASSERT((object->flags & OBJ_TMPFS_VREF) == 0,
("%s: object %p with OBJ_TMPFS_VREF but without vnode",
__func__, object));
KASSERT(object->un_pager.swp.writemappings == 0,
("%s: object %p has writemappings",
__func__, object));
VI_LOCK(vp);
KASSERT(vp->v_object == NULL, ("Not NULL v_object in tmpfs"));
vp->v_object = object;
object->un_pager.swp.swp_tmpfs = vp;
vm_object_set_flag(object, OBJ_TMPFS);
vn_irflag_set_locked(vp, VIRF_PGREAD);
VI_UNLOCK(vp);
VM_OBJECT_WUNLOCK(object);
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);
}
if (vp->v_type != VFIFO)
VN_LOCK_ASHARE(vp);
error = insmntque1(vp, mp, tmpfs_insmntque_dtr, NULL);
if (error != 0)
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:
if (error == 0) {
*vpp = vp;
#ifdef INVARIANTS
MPASS(*vpp != NULL && VOP_ISLOCKED(*vpp));
TMPFS_NODE_LOCK(node);
MPASS(*vpp == node->tn_vnode);
TMPFS_NODE_UNLOCK(node);
#endif
}
tmpfs_free_node(tm, node);
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);
TMPFS_NODE_ASSERT_LOCKED(node);
node->tn_vnode = NULL;
if ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0)
wakeup(&node->tn_vnode);
node->tn_vpstate &= ~TMPFS_VNODE_WRECLAIM;
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, const char *target)
{
int error;
struct tmpfs_dirent *de;
struct tmpfs_mount *tmp;
struct tmpfs_node *dnode;
struct tmpfs_node *node;
struct tmpfs_node *parent;
ASSERT_VOP_ELOCKED(dvp, "tmpfs_alloc_file");
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 <= TMPFS_LINK_MAX);
if (dnode->tn_links == TMPFS_LINK_MAX) {
return (EMLINK);
}
parent = dnode;
MPASS(parent != NULL);
} else
parent = NULL;
/* Allocate a node that represents the new file. */
error = tmpfs_alloc_node(dvp->v_mount, tmp, vap->va_type,
cnp->cn_cred->cr_uid, dnode->tn_gid, vap->va_mode, parent,
target, vap->va_rdev, &node);
if (error != 0)
return (error);
/* 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);
return (error);
}
/* 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);
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. */
if (cnp->cn_flags & ISWHITEOUT)
tmpfs_dir_whiteout_remove(dvp, cnp);
tmpfs_dir_attach(dvp, de);
return (0);
}
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);
}
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;
}
if ((cookie & TMPFS_DIRCOOKIE_MASK) != cookie) {
de = NULL;
} else {
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_CHANGED | TMPFS_NODE_MODIFIED;
dnode->tn_accessed = true;
tmpfs_update(vp);
}
/*
* 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);
}
}
de->td_cookie = de->td_hash;
} else
RB_REMOVE(tmpfs_dir, head, de);
dnode->tn_size -= sizeof(struct tmpfs_dirent);
dnode->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED;
dnode->tn_accessed = true;
tmpfs_update(vp);
}
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_mount *tm, 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_off = TMPFS_DIRCOOKIE_DOTDOT;
dent.d_type = DT_DIR;
dent.d_namlen = 1;
dent.d_name[0] = '.';
dent.d_reclen = GENERIC_DIRSIZ(&dent);
dirent_terminate(&dent);
if (dent.d_reclen > uio->uio_resid)
error = EJUSTRETURN;
else
error = uiomove(&dent, dent.d_reclen, uio);
tmpfs_set_accessed(tm, node);
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_mount *tm, struct tmpfs_node *node,
struct uio *uio, off_t next)
{
struct tmpfs_node *parent;
struct dirent dent;
int error;
TMPFS_VALIDATE_DIR(node);
MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT);
/*
* Return ENOENT if the current node is already removed.
*/
TMPFS_ASSERT_LOCKED(node);
parent = node->tn_dir.tn_parent;
if (parent == NULL)
return (ENOENT);
dent.d_fileno = parent->tn_id;
dent.d_off = next;
dent.d_type = DT_DIR;
dent.d_namlen = 2;
dent.d_name[0] = '.';
dent.d_name[1] = '.';
dent.d_reclen = GENERIC_DIRSIZ(&dent);
dirent_terminate(&dent);
if (dent.d_reclen > uio->uio_resid)
error = EJUSTRETURN;
else
error = uiomove(&dent, dent.d_reclen, uio);
tmpfs_set_accessed(tm, node);
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_mount *tm, struct tmpfs_node *node,
struct uio *uio, int maxcookies, u_long *cookies, int *ncookies)
{
struct tmpfs_dir_cursor dc;
struct tmpfs_dirent *de, *nde;
off_t off;
int error;
TMPFS_VALIDATE_DIR(node);
off = 0;
/*
* Lookup the node from the current offset. The starting offset of
* 0 will lookup both '.' and '..', and then the first real entry,
* or EOF if there are none. Then find all entries for the dir that
* fit into the buffer. Once no more entries are found (de == NULL),
* the offset is set to TMPFS_DIRCOOKIE_EOF, which will cause the next
* call to return 0.
*/
switch (uio->uio_offset) {
case TMPFS_DIRCOOKIE_DOT:
error = tmpfs_dir_getdotdent(tm, node, uio);
if (error != 0)
return (error);
uio->uio_offset = off = TMPFS_DIRCOOKIE_DOTDOT;
if (cookies != NULL)
cookies[(*ncookies)++] = off;
/* FALLTHROUGH */
case TMPFS_DIRCOOKIE_DOTDOT:
de = tmpfs_dir_first(node, &dc);
off = tmpfs_dirent_cookie(de);
error = tmpfs_dir_getdotdotdent(tm, node, uio, off);
if (error != 0)
return (error);
uio->uio_offset = off;
if (cookies != NULL)
cookies[(*ncookies)++] = off;
/* EOF. */
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 (cookies != NULL)
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_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;
}
nde = tmpfs_dir_next(node, &dc);
d.d_off = tmpfs_dirent_cookie(nde);
dirent_terminate(&d);
/*
* Copy the new dirent structure into the output buffer and
* advance pointers.
*/
error = uiomove(&d, d.d_reclen, uio);
if (error == 0) {
de = nde;
if (cookies != NULL) {
off = tmpfs_dirent_cookie(de);
MPASS(*ncookies < maxcookies);
cookies[(*ncookies)++] = off;
}
}
} while (error == 0 && uio->uio_resid > 0 && de != NULL);
/* Skip setting off when using cookies as it is already done above. */
if (cookies == NULL)
off = tmpfs_dirent_cookie(de);
/* Update the offset and cache. */
uio->uio_offset = off;
node->tn_dir.tn_readdir_lastn = off;
node->tn_dir.tn_readdir_lastp = de;
tmpfs_set_accessed(tm, node);
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;
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 (__predict_true(newpages == oldpages && newsize >= oldsize)) {
node->tn_size = newsize;
return (0);
}
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_grab(uobj, idx, VM_ALLOC_NOCREAT);
if (m != NULL) {
MPASS(vm_page_all_valid(m));
} else if (vm_pager_has_page(uobj, idx, NULL, NULL)) {
m = vm_page_alloc(uobj, idx, VM_ALLOC_NORMAL |
VM_ALLOC_WAITFAIL);
if (m == NULL)
goto retry;
vm_object_pip_add(uobj, 1);
VM_OBJECT_WUNLOCK(uobj);
rv = vm_pager_get_pages(uobj, &m, 1, NULL,
NULL);
VM_OBJECT_WLOCK(uobj);
vm_object_pip_wakeup(uobj);
if (rv == VM_PAGER_OK) {
/*
* Since the page was not resident,
* and therefore not recently
* accessed, immediately enqueue it
* for asynchronous laundering. The
* current operation is not regarded
* as an access.
*/
vm_page_launder(m);
} else {
vm_page_free(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_set_dirty(m);
vm_page_xunbusy(m);
}
}
/*
* Release any swap space and free any whole pages.
*/
if (newpages < oldpages)
vm_object_page_remove(uobj, newpages, 0, 0);
}
uobj->size = newpages;
VM_OBJECT_WUNLOCK(uobj);
atomic_add_long(&tmp->tm_pages_used, newpages - oldpages);
node->tn_size = newsize;
return (0);
}
void
tmpfs_check_mtime(struct vnode *vp)
{
struct tmpfs_node *node;
struct vm_object *obj;
ASSERT_VOP_ELOCKED(vp, "check_mtime");
if (vp->v_type != VREG)
return;
obj = vp->v_object;
KASSERT(obj->type == tmpfs_pager_type &&
(obj->flags & (OBJ_SWAP | OBJ_TMPFS)) ==
(OBJ_SWAP | OBJ_TMPFS), ("non-tmpfs obj"));
/* unlocked read */
if (obj->generation != obj->cleangeneration) {
VM_OBJECT_WLOCK(obj);
if (obj->generation != obj->cleangeneration) {
obj->cleangeneration = obj->generation;
node = VP_TO_TMPFS_NODE(vp);
node->tn_status |= TMPFS_NODE_MODIFIED |
TMPFS_NODE_CHANGED;
}
VM_OBJECT_WUNLOCK(obj);
}
}
/*
* 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;
ASSERT_VOP_ELOCKED(vp, "chflags");
node = VP_TO_TMPFS_NODE(vp);
if ((flags & ~(SF_APPEND | SF_ARCHIVED | SF_IMMUTABLE | SF_NOUNLINK |
UF_APPEND | UF_ARCHIVE | UF_HIDDEN | UF_IMMUTABLE | UF_NODUMP |
UF_NOUNLINK | UF_OFFLINE | UF_OPAQUE | UF_READONLY | UF_REPARSE |
UF_SPARSE | UF_SYSTEM)) != 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)) {
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;
ASSERT_VOP_ELOCKED(vp, "chflags2");
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;
mode_t newmode;
ASSERT_VOP_ELOCKED(vp, "chmod");
ASSERT_VOP_IN_SEQC(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))
return (EFTYPE);
}
if (!groupmember(node->tn_gid, cred) && (mode & S_ISGID)) {
error = priv_check_cred(cred, PRIV_VFS_SETGID);
if (error)
return (error);
}
newmode = node->tn_mode & ~ALLPERMS;
newmode |= mode & ALLPERMS;
atomic_store_short(&node->tn_mode, newmode);
node->tn_status |= TMPFS_NODE_CHANGED;
ASSERT_VOP_ELOCKED(vp, "chmod2");
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;
mode_t newmode;
ASSERT_VOP_ELOCKED(vp, "chown");
ASSERT_VOP_IN_SEQC(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)))
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)) {
newmode = node->tn_mode & ~(S_ISUID | S_ISGID);
atomic_store_short(&node->tn_mode, newmode);
}
}
ASSERT_VOP_ELOCKED(vp, "chown2");
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;
ASSERT_VOP_ELOCKED(vp, "chsize");
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.
*/
ASSERT_VOP_ELOCKED(vp, "chsize2");
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 vattr *vap,
struct ucred *cred, struct thread *l)
{
int error;
struct tmpfs_node *node;
ASSERT_VOP_ELOCKED(vp, "chtimes");
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);
error = vn_utimes_perm(vp, vap, cred, l);
if (error != 0)
return (error);
if (vap->va_atime.tv_sec != VNOVAL)
node->tn_accessed = true;
if (vap->va_mtime.tv_sec != VNOVAL)
node->tn_status |= TMPFS_NODE_MODIFIED;
if (vap->va_birthtime.tv_sec != VNOVAL)
node->tn_status |= TMPFS_NODE_MODIFIED;
tmpfs_itimes(vp, &vap->va_atime, &vap->va_mtime);
if (vap->va_birthtime.tv_sec != VNOVAL)
node->tn_birthtime = vap->va_birthtime;
ASSERT_VOP_ELOCKED(vp, "chtimes2");
return (0);
}
void
tmpfs_set_status(struct tmpfs_mount *tm, struct tmpfs_node *node, int status)
{
if ((node->tn_status & status) == status || tm->tm_ronly)
return;
TMPFS_NODE_LOCK(node);
node->tn_status |= status;
TMPFS_NODE_UNLOCK(node);
}
void
tmpfs_set_accessed(struct tmpfs_mount *tm, struct tmpfs_node *node)
{
if (node->tn_accessed || tm->tm_ronly)
return;
atomic_store_8(&node->tn_accessed, true);
}
/* Sync timestamps */
void
tmpfs_itimes(struct vnode *vp, const struct timespec *acc,
const struct timespec *mod)
{
struct tmpfs_node *node;
struct timespec now;
ASSERT_VOP_LOCKED(vp, "tmpfs_itimes");
node = VP_TO_TMPFS_NODE(vp);
if (!node->tn_accessed &&
(node->tn_status & (TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED)) == 0)
return;
vfs_timestamp(&now);
TMPFS_NODE_LOCK(node);
if (node->tn_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_MODIFIED | TMPFS_NODE_CHANGED);
node->tn_accessed = false;
TMPFS_NODE_UNLOCK(node);
/* XXX: FIX? The entropy here is desirable, but the harvesting may be expensive */
random_harvest_queue(node, sizeof(*node), RANDOM_FS_ATIME);
}
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);
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