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freebsd-dev/sys/fs/tmpfs/tmpfs_vnops.c
Xin LI 82cf92d483 Add locking around access to parent node, and bail out when the parent 
node is already freed rather than panicking the system.

PR:		kern/122038
Submitted by:	gk
Tested by:	pho
MFC after:	1 week
2009-10-11 07:03:56 +00:00

1567 lines
37 KiB
C
Raw Blame History

/* $NetBSD: tmpfs_vnops.c,v 1.39 2007/07/23 15:41:01 jmmv Exp $ */
/*-
* Copyright (c) 2005, 2006 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.
*/
/*
* tmpfs vnode interface.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/fcntl.h>
#include <sys/lockf.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/sched.h>
#include <sys/sf_buf.h>
#include <sys/stat.h>
#include <sys/systm.h>
#include <sys/unistd.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <machine/_inttypes.h>
#include <fs/fifofs/fifo.h>
#include <fs/tmpfs/tmpfs_vnops.h>
#include <fs/tmpfs/tmpfs.h>
/* --------------------------------------------------------------------- */
static int
tmpfs_lookup(struct vop_cachedlookup_args *v)
{
struct vnode *dvp = v->a_dvp;
struct vnode **vpp = v->a_vpp;
struct componentname *cnp = v->a_cnp;
int error;
struct tmpfs_dirent *de;
struct tmpfs_node *dnode;
dnode = VP_TO_TMPFS_DIR(dvp);
*vpp = NULLVP;
/* Check accessibility of requested node as a first step. */
error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, cnp->cn_thread);
if (error != 0)
goto out;
/* We cannot be requesting the parent directory of the root node. */
MPASS(IMPLIES(dnode->tn_type == VDIR &&
dnode->tn_dir.tn_parent == dnode,
!(cnp->cn_flags & ISDOTDOT)));
TMPFS_ASSERT_LOCKED(dnode);
if (dnode->tn_dir.tn_parent == NULL) {
error = ENOENT;
goto out;
}
if (cnp->cn_flags & ISDOTDOT) {
int ltype = 0;
ltype = VOP_ISLOCKED(dvp);
vhold(dvp);
VOP_UNLOCK(dvp, 0);
/* Allocate a new vnode on the matching entry. */
error = tmpfs_alloc_vp(dvp->v_mount, dnode->tn_dir.tn_parent,
cnp->cn_lkflags, vpp);
vn_lock(dvp, ltype | LK_RETRY);
vdrop(dvp);
} else if (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.') {
VREF(dvp);
*vpp = dvp;
error = 0;
} else {
de = tmpfs_dir_lookup(dnode, NULL, cnp);
if (de == NULL) {
/* The entry was not found in the directory.
* This is OK if we are creating or renaming an
* entry and are working on the last component of
* the path name. */
if ((cnp->cn_flags & ISLASTCN) &&
(cnp->cn_nameiop == CREATE || \
cnp->cn_nameiop == RENAME)) {
error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred,
cnp->cn_thread);
if (error != 0)
goto out;
/* Keep the component name in the buffer for
* future uses. */
cnp->cn_flags |= SAVENAME;
error = EJUSTRETURN;
} else
error = ENOENT;
} else {
struct tmpfs_node *tnode;
/* The entry was found, so get its associated
* tmpfs_node. */
tnode = de->td_node;
/* If we are not at the last path component and
* found a non-directory or non-link entry (which
* may itself be pointing to a directory), raise
* an error. */
if ((tnode->tn_type != VDIR &&
tnode->tn_type != VLNK) &&
!(cnp->cn_flags & ISLASTCN)) {
error = ENOTDIR;
goto out;
}
/* If we are deleting or renaming the entry, keep
* track of its tmpfs_dirent so that it can be
* easily deleted later. */
if ((cnp->cn_flags & ISLASTCN) &&
(cnp->cn_nameiop == DELETE ||
cnp->cn_nameiop == RENAME)) {
error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred,
cnp->cn_thread);
if (error != 0)
goto out;
/* Allocate a new vnode on the matching entry. */
error = tmpfs_alloc_vp(dvp->v_mount, tnode,
cnp->cn_lkflags, vpp);
if (error != 0)
goto out;
if ((dnode->tn_mode & S_ISTXT) &&
VOP_ACCESS(dvp, VADMIN, cnp->cn_cred, cnp->cn_thread) &&
VOP_ACCESS(*vpp, VADMIN, cnp->cn_cred, cnp->cn_thread)) {
error = EPERM;
vput(*vpp);
*vpp = NULL;
goto out;
}
cnp->cn_flags |= SAVENAME;
} else {
error = tmpfs_alloc_vp(dvp->v_mount, tnode,
cnp->cn_lkflags, vpp);
}
}
}
/* Store the result of this lookup in the cache. Avoid this if the
* request was for creation, as it does not improve timings on
* emprical tests. */
if ((cnp->cn_flags & MAKEENTRY) && cnp->cn_nameiop != CREATE)
cache_enter(dvp, *vpp, cnp);
out:
/* If there were no errors, *vpp cannot be null and it must be
* locked. */
MPASS(IFF(error == 0, *vpp != NULLVP && VOP_ISLOCKED(*vpp)));
return error;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_create(struct vop_create_args *v)
{
struct vnode *dvp = v->a_dvp;
struct vnode **vpp = v->a_vpp;
struct componentname *cnp = v->a_cnp;
struct vattr *vap = v->a_vap;
MPASS(vap->va_type == VREG || vap->va_type == VSOCK);
return tmpfs_alloc_file(dvp, vpp, vap, cnp, NULL);
}
/* --------------------------------------------------------------------- */
static int
tmpfs_mknod(struct vop_mknod_args *v)
{
struct vnode *dvp = v->a_dvp;
struct vnode **vpp = v->a_vpp;
struct componentname *cnp = v->a_cnp;
struct vattr *vap = v->a_vap;
if (vap->va_type != VBLK && vap->va_type != VCHR &&
vap->va_type != VFIFO)
return EINVAL;
return tmpfs_alloc_file(dvp, vpp, vap, cnp, NULL);
}
/* --------------------------------------------------------------------- */
static int
tmpfs_open(struct vop_open_args *v)
{
struct vnode *vp = v->a_vp;
int mode = v->a_mode;
int error;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(vp));
node = VP_TO_TMPFS_NODE(vp);
/* The file is still active but all its names have been removed
* (e.g. by a "rmdir $(pwd)"). It cannot be opened any more as
* it is about to die. */
if (node->tn_links < 1)
return (ENOENT);
/* If the file is marked append-only, deny write requests. */
if (node->tn_flags & APPEND && (mode & (FWRITE | O_APPEND)) == FWRITE)
error = EPERM;
else {
error = 0;
vnode_create_vobject(vp, node->tn_size, v->a_td);
}
MPASS(VOP_ISLOCKED(vp));
return error;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_close(struct vop_close_args *v)
{
struct vnode *vp = v->a_vp;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(vp));
node = VP_TO_TMPFS_NODE(vp);
if (node->tn_links > 0) {
/* Update node times. No need to do it if the node has
* been deleted, because it will vanish after we return. */
tmpfs_update(vp);
}
return 0;
}
/* --------------------------------------------------------------------- */
int
tmpfs_access(struct vop_access_args *v)
{
struct vnode *vp = v->a_vp;
accmode_t accmode = v->a_accmode;
struct ucred *cred = v->a_cred;
int error;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(vp));
node = VP_TO_TMPFS_NODE(vp);
switch (vp->v_type) {
case VDIR:
/* FALLTHROUGH */
case VLNK:
/* FALLTHROUGH */
case VREG:
if (accmode & VWRITE && vp->v_mount->mnt_flag & MNT_RDONLY) {
error = EROFS;
goto out;
}
break;
case VBLK:
/* FALLTHROUGH */
case VCHR:
/* FALLTHROUGH */
case VSOCK:
/* FALLTHROUGH */
case VFIFO:
break;
default:
error = EINVAL;
goto out;
}
if (accmode & VWRITE && node->tn_flags & IMMUTABLE) {
error = EPERM;
goto out;
}
error = vaccess(vp->v_type, node->tn_mode, node->tn_uid,
node->tn_gid, accmode, cred, NULL);
out:
MPASS(VOP_ISLOCKED(vp));
return error;
}
/* --------------------------------------------------------------------- */
int
tmpfs_getattr(struct vop_getattr_args *v)
{
struct vnode *vp = v->a_vp;
struct vattr *vap = v->a_vap;
struct tmpfs_node *node;
node = VP_TO_TMPFS_NODE(vp);
tmpfs_update(vp);
vap->va_type = vp->v_type;
vap->va_mode = node->tn_mode;
vap->va_nlink = node->tn_links;
vap->va_uid = node->tn_uid;
vap->va_gid = node->tn_gid;
vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
vap->va_fileid = node->tn_id;
vap->va_size = node->tn_size;
vap->va_blocksize = PAGE_SIZE;
vap->va_atime = node->tn_atime;
vap->va_mtime = node->tn_mtime;
vap->va_ctime = node->tn_ctime;
vap->va_birthtime = node->tn_birthtime;
vap->va_gen = node->tn_gen;
vap->va_flags = node->tn_flags;
vap->va_rdev = (vp->v_type == VBLK || vp->v_type == VCHR) ?
node->tn_rdev : NODEV;
vap->va_bytes = round_page(node->tn_size);
vap->va_filerev = 0;
return 0;
}
/* --------------------------------------------------------------------- */
/* XXX Should this operation be atomic? I think it should, but code in
* XXX other places (e.g., ufs) doesn't seem to be... */
int
tmpfs_setattr(struct vop_setattr_args *v)
{
struct vnode *vp = v->a_vp;
struct vattr *vap = v->a_vap;
struct ucred *cred = v->a_cred;
struct thread *td = curthread;
int error;
MPASS(VOP_ISLOCKED(vp));
error = 0;
/* Abort if any unsettable attribute is given. */
if (vap->va_type != VNON ||
vap->va_nlink != VNOVAL ||
vap->va_fsid != VNOVAL ||
vap->va_fileid != VNOVAL ||
vap->va_blocksize != VNOVAL ||
vap->va_gen != VNOVAL ||
vap->va_rdev != VNOVAL ||
vap->va_bytes != VNOVAL)
error = EINVAL;
if (error == 0 && (vap->va_flags != VNOVAL))
error = tmpfs_chflags(vp, vap->va_flags, cred, td);
if (error == 0 && (vap->va_size != VNOVAL))
error = tmpfs_chsize(vp, vap->va_size, cred, td);
if (error == 0 && (vap->va_uid != VNOVAL || vap->va_gid != VNOVAL))
error = tmpfs_chown(vp, vap->va_uid, vap->va_gid, cred, td);
if (error == 0 && (vap->va_mode != (mode_t)VNOVAL))
error = tmpfs_chmod(vp, vap->va_mode, cred, td);
if (error == 0 && ((vap->va_atime.tv_sec != VNOVAL &&
vap->va_atime.tv_nsec != VNOVAL) ||
(vap->va_mtime.tv_sec != VNOVAL &&
vap->va_mtime.tv_nsec != VNOVAL) ||
(vap->va_birthtime.tv_sec != VNOVAL &&
vap->va_birthtime.tv_nsec != VNOVAL)))
error = tmpfs_chtimes(vp, &vap->va_atime, &vap->va_mtime,
&vap->va_birthtime, vap->va_vaflags, cred, td);
/* Update the node times. We give preference to the error codes
* generated by this function rather than the ones that may arise
* from tmpfs_update. */
tmpfs_update(vp);
MPASS(VOP_ISLOCKED(vp));
return error;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_nocacheread(vm_object_t tobj, vm_pindex_t idx,
vm_offset_t offset, size_t tlen, struct uio *uio)
{
vm_page_t m;
int error;
VM_OBJECT_LOCK(tobj);
vm_object_pip_add(tobj, 1);
m = vm_page_grab(tobj, idx, VM_ALLOC_WIRED |
VM_ALLOC_ZERO | VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
if (m->valid != VM_PAGE_BITS_ALL) {
if (vm_pager_has_page(tobj, idx, NULL, NULL)) {
error = vm_pager_get_pages(tobj, &m, 1, 0);
if (error != 0) {
printf("tmpfs get pages from pager error [read]\n");
goto out;
}
} else
vm_page_zero_invalid(m, TRUE);
}
VM_OBJECT_UNLOCK(tobj);
error = uiomove_fromphys(&m, offset, tlen, uio);
VM_OBJECT_LOCK(tobj);
out:
vm_page_lock_queues();
vm_page_unwire(m, TRUE);
vm_page_unlock_queues();
vm_page_wakeup(m);
vm_object_pip_subtract(tobj, 1);
VM_OBJECT_UNLOCK(tobj);
return (error);
}
static __inline int
tmpfs_nocacheread_buf(vm_object_t tobj, vm_pindex_t idx,
vm_offset_t offset, size_t tlen, void *buf)
{
struct uio uio;
struct iovec iov;
uio.uio_iovcnt = 1;
uio.uio_iov = &iov;
iov.iov_base = buf;
iov.iov_len = tlen;
uio.uio_offset = 0;
uio.uio_resid = tlen;
uio.uio_rw = UIO_READ;
uio.uio_segflg = UIO_SYSSPACE;
uio.uio_td = curthread;
return (tmpfs_nocacheread(tobj, idx, offset, tlen, &uio));
}
static int
tmpfs_mappedread(vm_object_t vobj, vm_object_t tobj, size_t len, struct uio *uio)
{
struct sf_buf *sf;
vm_pindex_t idx;
vm_page_t m;
vm_offset_t offset;
off_t addr;
size_t tlen;
char *ma;
int error;
addr = uio->uio_offset;
idx = OFF_TO_IDX(addr);
offset = addr & PAGE_MASK;
tlen = MIN(PAGE_SIZE - offset, len);
if ((vobj == NULL) ||
(vobj->resident_page_count == 0 && vobj->cache == NULL))
goto nocache;
VM_OBJECT_LOCK(vobj);
lookupvpg:
if (((m = vm_page_lookup(vobj, idx)) != NULL) &&
vm_page_is_valid(m, offset, tlen)) {
if (vm_page_sleep_if_busy(m, FALSE, "tmfsmr"))
goto lookupvpg;
vm_page_busy(m);
VM_OBJECT_UNLOCK(vobj);
error = uiomove_fromphys(&m, offset, tlen, uio);
VM_OBJECT_LOCK(vobj);
vm_page_wakeup(m);
VM_OBJECT_UNLOCK(vobj);
return (error);
} else if (m != NULL && uio->uio_segflg == UIO_NOCOPY) {
if (vm_page_sleep_if_busy(m, FALSE, "tmfsmr"))
goto lookupvpg;
vm_page_busy(m);
VM_OBJECT_UNLOCK(vobj);
sched_pin();
sf = sf_buf_alloc(m, SFB_CPUPRIVATE);
ma = (char *)sf_buf_kva(sf);
error = tmpfs_nocacheread_buf(tobj, idx, offset, tlen,
ma + offset);
if (error == 0) {
uio->uio_offset += tlen;
uio->uio_resid -= tlen;
}
sf_buf_free(sf);
sched_unpin();
VM_OBJECT_LOCK(vobj);
vm_page_wakeup(m);
VM_OBJECT_UNLOCK(vobj);
return (error);
}
VM_OBJECT_UNLOCK(vobj);
nocache:
error = tmpfs_nocacheread(tobj, idx, offset, tlen, uio);
return (error);
}
static int
tmpfs_read(struct vop_read_args *v)
{
struct vnode *vp = v->a_vp;
struct uio *uio = v->a_uio;
struct tmpfs_node *node;
vm_object_t uobj;
size_t len;
int resid;
int error = 0;
node = VP_TO_TMPFS_NODE(vp);
if (vp->v_type != VREG) {
error = EISDIR;
goto out;
}
if (uio->uio_offset < 0) {
error = EINVAL;
goto out;
}
node->tn_status |= TMPFS_NODE_ACCESSED;
uobj = node->tn_reg.tn_aobj;
while ((resid = uio->uio_resid) > 0) {
error = 0;
if (node->tn_size <= uio->uio_offset)
break;
len = MIN(node->tn_size - uio->uio_offset, resid);
if (len == 0)
break;
error = tmpfs_mappedread(vp->v_object, uobj, len, uio);
if ((error != 0) || (resid == uio->uio_resid))
break;
}
out:
return error;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_mappedwrite(vm_object_t vobj, vm_object_t tobj, size_t len, struct uio *uio)
{
vm_pindex_t idx;
vm_page_t vpg, tpg;
vm_offset_t offset;
off_t addr;
size_t tlen;
int error;
error = 0;
addr = uio->uio_offset;
idx = OFF_TO_IDX(addr);
offset = addr & PAGE_MASK;
tlen = MIN(PAGE_SIZE - offset, len);
if ((vobj == NULL) ||
(vobj->resident_page_count == 0 && vobj->cache == NULL)) {
vpg = NULL;
goto nocache;
}
VM_OBJECT_LOCK(vobj);
lookupvpg:
if (((vpg = vm_page_lookup(vobj, idx)) != NULL) &&
vm_page_is_valid(vpg, offset, tlen)) {
if (vm_page_sleep_if_busy(vpg, FALSE, "tmfsmw"))
goto lookupvpg;
vm_page_busy(vpg);
vm_page_lock_queues();
vm_page_undirty(vpg);
vm_page_unlock_queues();
VM_OBJECT_UNLOCK(vobj);
error = uiomove_fromphys(&vpg, offset, tlen, uio);
} else {
if (__predict_false(vobj->cache != NULL))
vm_page_cache_free(vobj, idx, idx + 1);
VM_OBJECT_UNLOCK(vobj);
vpg = NULL;
}
nocache:
VM_OBJECT_LOCK(tobj);
vm_object_pip_add(tobj, 1);
tpg = vm_page_grab(tobj, idx, VM_ALLOC_WIRED |
VM_ALLOC_ZERO | VM_ALLOC_NORMAL | VM_ALLOC_RETRY);
if (tpg->valid != VM_PAGE_BITS_ALL) {
if (vm_pager_has_page(tobj, idx, NULL, NULL)) {
error = vm_pager_get_pages(tobj, &tpg, 1, 0);
if (error != 0) {
printf("tmpfs get pages from pager error [write]\n");
goto out;
}
} else
vm_page_zero_invalid(tpg, TRUE);
}
VM_OBJECT_UNLOCK(tobj);
if (vpg == NULL)
error = uiomove_fromphys(&tpg, offset, tlen, uio);
else {
KASSERT(vpg->valid == VM_PAGE_BITS_ALL, ("parts of vpg invalid"));
pmap_copy_page(vpg, tpg);
}
VM_OBJECT_LOCK(tobj);
out:
if (vobj != NULL)
VM_OBJECT_LOCK(vobj);
vm_page_lock_queues();
if (error == 0) {
KASSERT(tpg->valid == VM_PAGE_BITS_ALL,
("parts of tpg invalid"));
vm_page_dirty(tpg);
}
vm_page_unwire(tpg, TRUE);
vm_page_unlock_queues();
vm_page_wakeup(tpg);
if (vpg != NULL)
vm_page_wakeup(vpg);
if (vobj != NULL)
VM_OBJECT_UNLOCK(vobj);
vm_object_pip_subtract(tobj, 1);
VM_OBJECT_UNLOCK(tobj);
return (error);
}
static int
tmpfs_write(struct vop_write_args *v)
{
struct vnode *vp = v->a_vp;
struct uio *uio = v->a_uio;
int ioflag = v->a_ioflag;
struct thread *td = uio->uio_td;
boolean_t extended;
int error = 0;
off_t oldsize;
struct tmpfs_node *node;
vm_object_t uobj;
size_t len;
int resid;
node = VP_TO_TMPFS_NODE(vp);
oldsize = node->tn_size;
if (uio->uio_offset < 0 || vp->v_type != VREG) {
error = EINVAL;
goto out;
}
if (uio->uio_resid == 0) {
error = 0;
goto out;
}
if (ioflag & IO_APPEND)
uio->uio_offset = node->tn_size;
if (uio->uio_offset + uio->uio_resid >
VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize)
return (EFBIG);
if (vp->v_type == VREG && td != NULL) {
PROC_LOCK(td->td_proc);
if (uio->uio_offset + uio->uio_resid >
lim_cur(td->td_proc, RLIMIT_FSIZE)) {
psignal(td->td_proc, SIGXFSZ);
PROC_UNLOCK(td->td_proc);
return (EFBIG);
}
PROC_UNLOCK(td->td_proc);
}
extended = uio->uio_offset + uio->uio_resid > node->tn_size;
if (extended) {
error = tmpfs_reg_resize(vp, uio->uio_offset + uio->uio_resid);
if (error != 0)
goto out;
}
uobj = node->tn_reg.tn_aobj;
while ((resid = uio->uio_resid) > 0) {
if (node->tn_size <= uio->uio_offset)
break;
len = MIN(node->tn_size - uio->uio_offset, resid);
if (len == 0)
break;
error = tmpfs_mappedwrite(vp->v_object, uobj, len, uio);
if ((error != 0) || (resid == uio->uio_resid))
break;
}
node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED |
(extended ? TMPFS_NODE_CHANGED : 0);
if (node->tn_mode & (S_ISUID | S_ISGID)) {
if (priv_check_cred(v->a_cred, PRIV_VFS_RETAINSUGID, 0))
node->tn_mode &= ~(S_ISUID | S_ISGID);
}
if (error != 0)
(void)tmpfs_reg_resize(vp, oldsize);
out:
MPASS(IMPLIES(error == 0, uio->uio_resid == 0));
MPASS(IMPLIES(error != 0, oldsize == node->tn_size));
return error;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_fsync(struct vop_fsync_args *v)
{
struct vnode *vp = v->a_vp;
MPASS(VOP_ISLOCKED(vp));
tmpfs_update(vp);
return 0;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_remove(struct vop_remove_args *v)
{
struct vnode *dvp = v->a_dvp;
struct vnode *vp = v->a_vp;
int error;
struct tmpfs_dirent *de;
struct tmpfs_mount *tmp;
struct tmpfs_node *dnode;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(dvp));
MPASS(VOP_ISLOCKED(vp));
if (vp->v_type == VDIR) {
error = EISDIR;
goto out;
}
dnode = VP_TO_TMPFS_DIR(dvp);
node = VP_TO_TMPFS_NODE(vp);
tmp = VFS_TO_TMPFS(vp->v_mount);
de = tmpfs_dir_lookup(dnode, node, v->a_cnp);
MPASS(de != NULL);
/* Files marked as immutable or append-only cannot be deleted. */
if ((node->tn_flags & (IMMUTABLE | APPEND | NOUNLINK)) ||
(dnode->tn_flags & APPEND)) {
error = EPERM;
goto out;
}
/* Remove the entry from the directory; as it is a file, we do not
* have to change the number of hard links of the directory. */
tmpfs_dir_detach(dvp, de);
/* Free the directory entry we just deleted. Note that the node
* referred by it will not be removed until the vnode is really
* reclaimed. */
tmpfs_free_dirent(tmp, de, TRUE);
if (node->tn_links > 0)
node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \
TMPFS_NODE_MODIFIED;
error = 0;
out:
return error;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_link(struct vop_link_args *v)
{
struct vnode *dvp = v->a_tdvp;
struct vnode *vp = v->a_vp;
struct componentname *cnp = v->a_cnp;
int error;
struct tmpfs_dirent *de;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(dvp));
MPASS(cnp->cn_flags & HASBUF);
MPASS(dvp != vp); /* XXX When can this be false? */
node = VP_TO_TMPFS_NODE(vp);
/* XXX: Why aren't the following two tests done by the caller? */
/* Hard links of directories are forbidden. */
if (vp->v_type == VDIR) {
error = EPERM;
goto out;
}
/* Cannot create cross-device links. */
if (dvp->v_mount != vp->v_mount) {
error = EXDEV;
goto out;
}
/* Ensure that we do not overflow the maximum number of links imposed
* by the system. */
MPASS(node->tn_links <= LINK_MAX);
if (node->tn_links == LINK_MAX) {
error = EMLINK;
goto out;
}
/* We cannot create links of files marked immutable or append-only. */
if (node->tn_flags & (IMMUTABLE | APPEND)) {
error = EPERM;
goto out;
}
/* Allocate a new directory entry to represent the node. */
error = tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount), node,
cnp->cn_nameptr, cnp->cn_namelen, &de);
if (error != 0)
goto out;
/* Insert the new directory entry into the appropriate directory. */
tmpfs_dir_attach(dvp, de);
/* vp link count has changed, so update node times. */
node->tn_status |= TMPFS_NODE_CHANGED;
tmpfs_update(vp);
error = 0;
out:
return error;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_rename(struct vop_rename_args *v)
{
struct vnode *fdvp = v->a_fdvp;
struct vnode *fvp = v->a_fvp;
struct componentname *fcnp = v->a_fcnp;
struct vnode *tdvp = v->a_tdvp;
struct vnode *tvp = v->a_tvp;
struct componentname *tcnp = v->a_tcnp;
char *newname;
int error;
struct tmpfs_dirent *de;
struct tmpfs_mount *tmp;
struct tmpfs_node *fdnode;
struct tmpfs_node *fnode;
struct tmpfs_node *tnode;
struct tmpfs_node *tdnode;
MPASS(VOP_ISLOCKED(tdvp));
MPASS(IMPLIES(tvp != NULL, VOP_ISLOCKED(tvp)));
MPASS(fcnp->cn_flags & HASBUF);
MPASS(tcnp->cn_flags & HASBUF);
tnode = (tvp == NULL) ? NULL : VP_TO_TMPFS_NODE(tvp);
/* Disallow cross-device renames.
* XXX Why isn't this done by the caller? */
if (fvp->v_mount != tdvp->v_mount ||
(tvp != NULL && fvp->v_mount != tvp->v_mount)) {
error = EXDEV;
goto out;
}
tmp = VFS_TO_TMPFS(tdvp->v_mount);
tdnode = VP_TO_TMPFS_DIR(tdvp);
/* If source and target are the same file, there is nothing to do. */
if (fvp == tvp) {
error = 0;
goto out;
}
/* If we need to move the directory between entries, lock the
* source so that we can safely operate on it. */
if (tdvp != fdvp) {
error = vn_lock(fdvp, LK_EXCLUSIVE | LK_RETRY);
if (error != 0)
goto out;
}
fdnode = VP_TO_TMPFS_DIR(fdvp);
fnode = VP_TO_TMPFS_NODE(fvp);
de = tmpfs_dir_lookup(fdnode, fnode, fcnp);
/* Avoid manipulating '.' and '..' entries. */
if (de == NULL) {
MPASS(fvp->v_type == VDIR);
error = EINVAL;
goto out_locked;
}
MPASS(de->td_node == fnode);
/* If re-naming a directory to another preexisting directory
* ensure that the target directory is empty so that its
* removal causes no side effects.
* Kern_rename gurantees the destination to be a directory
* if the source is one. */
if (tvp != NULL) {
MPASS(tnode != NULL);
if ((tnode->tn_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
(tdnode->tn_flags & (APPEND | IMMUTABLE))) {
error = EPERM;
goto out_locked;
}
if (fnode->tn_type == VDIR && tnode->tn_type == VDIR) {
if (tnode->tn_size > 0) {
error = ENOTEMPTY;
goto out_locked;
}
} else if (fnode->tn_type == VDIR && tnode->tn_type != VDIR) {
error = ENOTDIR;
goto out_locked;
} else if (fnode->tn_type != VDIR && tnode->tn_type == VDIR) {
error = EISDIR;
goto out_locked;
} else {
MPASS(fnode->tn_type != VDIR &&
tnode->tn_type != VDIR);
}
}
if ((fnode->tn_flags & (NOUNLINK | IMMUTABLE | APPEND))
|| (fdnode->tn_flags & (APPEND | IMMUTABLE))) {
error = EPERM;
goto out_locked;
}
/* Ensure that we have enough memory to hold the new name, if it
* has to be changed. */
if (fcnp->cn_namelen != tcnp->cn_namelen ||
bcmp(fcnp->cn_nameptr, tcnp->cn_nameptr, fcnp->cn_namelen) != 0) {
newname = malloc(tcnp->cn_namelen, M_TMPFSNAME, M_WAITOK);
} else
newname = NULL;
/* If the node is being moved to another directory, we have to do
* the move. */
if (fdnode != tdnode) {
/* In case we are moving a directory, we have to adjust its
* parent to point to the new parent. */
if (de->td_node->tn_type == VDIR) {
struct tmpfs_node *n;
/* Ensure the target directory is not a child of the
* directory being moved. Otherwise, we'd end up
* with stale nodes. */
n = tdnode;
/* TMPFS_LOCK garanties that no nodes are freed while
* traversing the list. Nodes can only be marked as
* removed: tn_parent == NULL. */
TMPFS_LOCK(tmp);
TMPFS_NODE_LOCK(n);
while (n != n->tn_dir.tn_parent) {
struct tmpfs_node *parent;
if (n == fnode) {
TMPFS_NODE_UNLOCK(n);
TMPFS_UNLOCK(tmp);
error = EINVAL;
if (newname != NULL)
free(newname, M_TMPFSNAME);
goto out_locked;
}
parent = n->tn_dir.tn_parent;
TMPFS_NODE_UNLOCK(n);
if (parent == NULL) {
n = NULL;
break;
}
TMPFS_NODE_LOCK(parent);
if (parent->tn_dir.tn_parent == NULL) {
TMPFS_NODE_UNLOCK(parent);
n = NULL;
break;
}
n = parent;
}
TMPFS_UNLOCK(tmp);
if (n == NULL) {
error = EINVAL;
if (newname != NULL)
free(newname, M_TMPFSNAME);
goto out_locked;
}
TMPFS_NODE_UNLOCK(n);
/* Adjust the parent pointer. */
TMPFS_VALIDATE_DIR(fnode);
TMPFS_NODE_LOCK(de->td_node);
de->td_node->tn_dir.tn_parent = tdnode;
TMPFS_NODE_UNLOCK(de->td_node);
/* As a result of changing the target of the '..'
* entry, the link count of the source and target
* directories has to be adjusted. */
TMPFS_NODE_LOCK(tdnode);
TMPFS_ASSERT_LOCKED(tdnode);
tdnode->tn_links++;
TMPFS_NODE_UNLOCK(tdnode);
TMPFS_NODE_LOCK(fdnode);
TMPFS_ASSERT_LOCKED(fdnode);
fdnode->tn_links--;
TMPFS_NODE_UNLOCK(fdnode);
}
/* Do the move: just remove the entry from the source directory
* and insert it into the target one. */
tmpfs_dir_detach(fdvp, de);
tmpfs_dir_attach(tdvp, de);
}
/* If the name has changed, we need to make it effective by changing
* it in the directory entry. */
if (newname != NULL) {
MPASS(tcnp->cn_namelen <= MAXNAMLEN);
free(de->td_name, M_TMPFSNAME);
de->td_namelen = (uint16_t)tcnp->cn_namelen;
memcpy(newname, tcnp->cn_nameptr, tcnp->cn_namelen);
de->td_name = newname;
fnode->tn_status |= TMPFS_NODE_CHANGED;
tdnode->tn_status |= TMPFS_NODE_MODIFIED;
}
/* If we are overwriting an entry, we have to remove the old one
* from the target directory. */
if (tvp != NULL) {
/* Remove the old entry from the target directory. */
de = tmpfs_dir_lookup(tdnode, tnode, tcnp);
tmpfs_dir_detach(tdvp, de);
/* Free the directory entry we just deleted. Note that the
* node referred by it will not be removed until the vnode is
* really reclaimed. */
tmpfs_free_dirent(VFS_TO_TMPFS(tvp->v_mount), de, TRUE);
}
error = 0;
out_locked:
if (fdnode != tdnode)
VOP_UNLOCK(fdvp, 0);
out:
/* Release target nodes. */
/* XXX: I don't understand when tdvp can be the same as tvp, but
* other code takes care of this... */
if (tdvp == tvp)
vrele(tdvp);
else
vput(tdvp);
if (tvp != NULL)
vput(tvp);
/* Release source nodes. */
vrele(fdvp);
vrele(fvp);
return error;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_mkdir(struct vop_mkdir_args *v)
{
struct vnode *dvp = v->a_dvp;
struct vnode **vpp = v->a_vpp;
struct componentname *cnp = v->a_cnp;
struct vattr *vap = v->a_vap;
MPASS(vap->va_type == VDIR);
return tmpfs_alloc_file(dvp, vpp, vap, cnp, NULL);
}
/* --------------------------------------------------------------------- */
static int
tmpfs_rmdir(struct vop_rmdir_args *v)
{
struct vnode *dvp = v->a_dvp;
struct vnode *vp = v->a_vp;
int error;
struct tmpfs_dirent *de;
struct tmpfs_mount *tmp;
struct tmpfs_node *dnode;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(dvp));
MPASS(VOP_ISLOCKED(vp));
tmp = VFS_TO_TMPFS(dvp->v_mount);
dnode = VP_TO_TMPFS_DIR(dvp);
node = VP_TO_TMPFS_DIR(vp);
/* Directories with more than two entries ('.' and '..') cannot be
* removed. */
if (node->tn_size > 0) {
error = ENOTEMPTY;
goto out;
}
if ((dnode->tn_flags & APPEND)
|| (node->tn_flags & (NOUNLINK | IMMUTABLE | APPEND))) {
error = EPERM;
goto out;
}
/* This invariant holds only if we are not trying to remove "..".
* We checked for that above so this is safe now. */
MPASS(node->tn_dir.tn_parent == dnode);
/* Get the directory entry associated with node (vp). This was
* filled by tmpfs_lookup while looking up the entry. */
de = tmpfs_dir_lookup(dnode, node, v->a_cnp);
MPASS(TMPFS_DIRENT_MATCHES(de,
v->a_cnp->cn_nameptr,
v->a_cnp->cn_namelen));
/* Check flags to see if we are allowed to remove the directory. */
if (dnode->tn_flags & APPEND
|| node->tn_flags & (NOUNLINK | IMMUTABLE | APPEND)) {
error = EPERM;
goto out;
}
/* Detach the directory entry from the directory (dnode). */
tmpfs_dir_detach(dvp, de);
/* No vnode should be allocated for this entry from this point */
TMPFS_NODE_LOCK(node);
TMPFS_ASSERT_ELOCKED(node);
node->tn_links--;
node->tn_dir.tn_parent = NULL;
node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \
TMPFS_NODE_MODIFIED;
TMPFS_NODE_UNLOCK(node);
TMPFS_NODE_LOCK(dnode);
TMPFS_ASSERT_ELOCKED(dnode);
dnode->tn_links--;
dnode->tn_status |= TMPFS_NODE_ACCESSED | \
TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED;
TMPFS_NODE_UNLOCK(dnode);
cache_purge(dvp);
cache_purge(vp);
/* Free the directory entry we just deleted. Note that the node
* referred by it will not be removed until the vnode is really
* reclaimed. */
tmpfs_free_dirent(tmp, de, TRUE);
/* Release the deleted vnode (will destroy the node, notify
* interested parties and clean it from the cache). */
dnode->tn_status |= TMPFS_NODE_CHANGED;
tmpfs_update(dvp);
error = 0;
out:
return error;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_symlink(struct vop_symlink_args *v)
{
struct vnode *dvp = v->a_dvp;
struct vnode **vpp = v->a_vpp;
struct componentname *cnp = v->a_cnp;
struct vattr *vap = v->a_vap;
char *target = v->a_target;
#ifdef notyet /* XXX FreeBSD BUG: kern_symlink is not setting VLNK */
MPASS(vap->va_type == VLNK);
#else
vap->va_type = VLNK;
#endif
return tmpfs_alloc_file(dvp, vpp, vap, cnp, target);
}
/* --------------------------------------------------------------------- */
static int
tmpfs_readdir(struct vop_readdir_args *v)
{
struct vnode *vp = v->a_vp;
struct uio *uio = v->a_uio;
int *eofflag = v->a_eofflag;
u_long **cookies = v->a_cookies;
int *ncookies = v->a_ncookies;
int error;
off_t startoff;
off_t cnt = 0;
struct tmpfs_node *node;
/* This operation only makes sense on directory nodes. */
if (vp->v_type != VDIR)
return ENOTDIR;
node = VP_TO_TMPFS_DIR(vp);
startoff = uio->uio_offset;
if (uio->uio_offset == TMPFS_DIRCOOKIE_DOT) {
error = tmpfs_dir_getdotdent(node, uio);
if (error != 0)
goto outok;
cnt++;
}
if (uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT) {
error = tmpfs_dir_getdotdotdent(node, uio);
if (error != 0)
goto outok;
cnt++;
}
error = tmpfs_dir_getdents(node, uio, &cnt);
outok:
MPASS(error >= -1);
if (error == -1)
error = 0;
if (eofflag != NULL)
*eofflag =
(error == 0 && uio->uio_offset == TMPFS_DIRCOOKIE_EOF);
/* Update NFS-related variables. */
if (error == 0 && cookies != NULL && ncookies != NULL) {
off_t i;
off_t off = startoff;
struct tmpfs_dirent *de = NULL;
*ncookies = cnt;
*cookies = malloc(cnt * sizeof(off_t), M_TEMP, M_WAITOK);
for (i = 0; i < cnt; i++) {
MPASS(off != TMPFS_DIRCOOKIE_EOF);
if (off == TMPFS_DIRCOOKIE_DOT) {
off = TMPFS_DIRCOOKIE_DOTDOT;
} else {
if (off == TMPFS_DIRCOOKIE_DOTDOT) {
de = TAILQ_FIRST(&node->tn_dir.tn_dirhead);
} else if (de != NULL) {
de = TAILQ_NEXT(de, td_entries);
} else {
de = tmpfs_dir_lookupbycookie(node,
off);
MPASS(de != NULL);
de = TAILQ_NEXT(de, td_entries);
}
if (de == NULL)
off = TMPFS_DIRCOOKIE_EOF;
else
off = tmpfs_dircookie(de);
}
(*cookies)[i] = off;
}
MPASS(uio->uio_offset == off);
}
return error;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_readlink(struct vop_readlink_args *v)
{
struct vnode *vp = v->a_vp;
struct uio *uio = v->a_uio;
int error;
struct tmpfs_node *node;
MPASS(uio->uio_offset == 0);
MPASS(vp->v_type == VLNK);
node = VP_TO_TMPFS_NODE(vp);
error = uiomove(node->tn_link, MIN(node->tn_size, uio->uio_resid),
uio);
node->tn_status |= TMPFS_NODE_ACCESSED;
return error;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_inactive(struct vop_inactive_args *v)
{
struct vnode *vp = v->a_vp;
struct thread *l = v->a_td;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(vp));
node = VP_TO_TMPFS_NODE(vp);
if (node->tn_links == 0)
vrecycle(vp, l);
return 0;
}
/* --------------------------------------------------------------------- */
int
tmpfs_reclaim(struct vop_reclaim_args *v)
{
struct vnode *vp = v->a_vp;
struct tmpfs_mount *tmp;
struct tmpfs_node *node;
node = VP_TO_TMPFS_NODE(vp);
tmp = VFS_TO_TMPFS(vp->v_mount);
vnode_destroy_vobject(vp);
cache_purge(vp);
TMPFS_NODE_LOCK(node);
TMPFS_ASSERT_ELOCKED(node);
tmpfs_free_vp(vp);
/* If the node referenced by this vnode was deleted by the user,
* we must free its associated data structures (now that the vnode
* is being reclaimed). */
if (node->tn_links == 0 &&
(node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0) {
node->tn_vpstate = TMPFS_VNODE_DOOMED;
TMPFS_NODE_UNLOCK(node);
tmpfs_free_node(tmp, node);
} else
TMPFS_NODE_UNLOCK(node);
MPASS(vp->v_data == NULL);
return 0;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_print(struct vop_print_args *v)
{
struct vnode *vp = v->a_vp;
struct tmpfs_node *node;
node = VP_TO_TMPFS_NODE(vp);
printf("tag VT_TMPFS, tmpfs_node %p, flags 0x%x, links %d\n",
node, node->tn_flags, node->tn_links);
printf("\tmode 0%o, owner %d, group %d, size %" PRIdMAX
", status 0x%x\n",
node->tn_mode, node->tn_uid, node->tn_gid,
(uintmax_t)node->tn_size, node->tn_status);
if (vp->v_type == VFIFO)
fifo_printinfo(vp);
printf("\n");
return 0;
}
/* --------------------------------------------------------------------- */
static int
tmpfs_pathconf(struct vop_pathconf_args *v)
{
int name = v->a_name;
register_t *retval = v->a_retval;
int error;
error = 0;
switch (name) {
case _PC_LINK_MAX:
*retval = LINK_MAX;
break;
case _PC_NAME_MAX:
*retval = NAME_MAX;
break;
case _PC_PATH_MAX:
*retval = PATH_MAX;
break;
case _PC_PIPE_BUF:
*retval = PIPE_BUF;
break;
case _PC_CHOWN_RESTRICTED:
*retval = 1;
break;
case _PC_NO_TRUNC:
*retval = 1;
break;
case _PC_SYNC_IO:
*retval = 1;
break;
case _PC_FILESIZEBITS:
*retval = 0; /* XXX Don't know which value should I return. */
break;
default:
error = EINVAL;
}
return error;
}
static int
tmpfs_vptofh(struct vop_vptofh_args *ap)
{
struct tmpfs_fid *tfhp;
struct tmpfs_node *node;
tfhp = (struct tmpfs_fid *)ap->a_fhp;
node = VP_TO_TMPFS_NODE(ap->a_vp);
tfhp->tf_len = sizeof(struct tmpfs_fid);
tfhp->tf_id = node->tn_id;
tfhp->tf_gen = node->tn_gen;
return (0);
}
/* --------------------------------------------------------------------- */
/*
* vnode operations vector used for files stored in a tmpfs file system.
*/
struct vop_vector tmpfs_vnodeop_entries = {
.vop_default = &default_vnodeops,
.vop_lookup = vfs_cache_lookup,
.vop_cachedlookup = tmpfs_lookup,
.vop_create = tmpfs_create,
.vop_mknod = tmpfs_mknod,
.vop_open = tmpfs_open,
.vop_close = tmpfs_close,
.vop_access = tmpfs_access,
.vop_getattr = tmpfs_getattr,
.vop_setattr = tmpfs_setattr,
.vop_read = tmpfs_read,
.vop_write = tmpfs_write,
.vop_fsync = tmpfs_fsync,
.vop_remove = tmpfs_remove,
.vop_link = tmpfs_link,
.vop_rename = tmpfs_rename,
.vop_mkdir = tmpfs_mkdir,
.vop_rmdir = tmpfs_rmdir,
.vop_symlink = tmpfs_symlink,
.vop_readdir = tmpfs_readdir,
.vop_readlink = tmpfs_readlink,
.vop_inactive = tmpfs_inactive,
.vop_reclaim = tmpfs_reclaim,
.vop_print = tmpfs_print,
.vop_pathconf = tmpfs_pathconf,
.vop_vptofh = tmpfs_vptofh,
.vop_bmap = VOP_EOPNOTSUPP,
};
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