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freebsd-skq/sys/fs/tmpfs/tmpfs_vnops.c
Mark Johnston 785eb42adf Clear the cookie pointer on error in tmpfs_readdir(). 
It is otherwise left dangling, and callers that request cookies always free
the cookie buffer, even when VOP_READDIR(9) returns an error. This results
in a double free if tmpfs_readdir() returns an error to the NFS server or
the Linux getdents(2) emulation code.

Reported by:	pho
MFC after:	1 week
Security:	double free of malloc(9)-backed memory
Sponsored by:	EMC / Isilon Storage Division
2016-02-12 20:43:53 +00:00

1426 lines
34 KiB
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/* $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/lock.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/sched.h>
#include <sys/stat.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/unistd.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <fs/tmpfs/tmpfs_vnops.h>
#include <fs/tmpfs/tmpfs.h>
SYSCTL_DECL(_vfs_tmpfs);
static volatile int tmpfs_rename_restarts;
SYSCTL_INT(_vfs_tmpfs, OID_AUTO, rename_restarts, CTLFLAG_RD,
__DEVOLATILE(int *, &tmpfs_rename_restarts), 0,
"Times rename had to restart due to lock contention");
static int
tmpfs_vn_get_ino_alloc(struct mount *mp, void *arg, int lkflags,
struct vnode **rvp)
{
return (tmpfs_alloc_vp(mp, arg, lkflags, rvp));
}
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;
struct tmpfs_dirent *de;
struct tmpfs_node *dnode;
int error;
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) {
error = vn_vget_ino_gen(dvp, tmpfs_vn_get_ino_alloc,
dnode->tn_dir.tn_parent, cnp->cn_lkflags, vpp);
if (error != 0)
goto out;
} 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 && de->td_node == NULL)
cnp->cn_flags |= ISWHITEOUT;
if (de == NULL || de->td_node == 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 ||
(cnp->cn_nameiop == DELETE &&
cnp->cn_flags & DOWHITEOUT &&
cnp->cn_flags & ISWHITEOUT))) {
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);
if (error != 0)
goto out;
}
}
}
/* 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) != 0)
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;
int error;
MPASS(vap->va_type == VREG || vap->va_type == VSOCK);
error = tmpfs_alloc_file(dvp, vpp, vap, cnp, NULL);
if (error == 0 && (cnp->cn_flags & MAKEENTRY) != 0)
cache_enter(dvp, *vpp, cnp);
return (error);
}
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;
/* For regular files, the call below is nop. */
KASSERT(vp->v_type != VREG || (node->tn_reg.tn_aobj->flags &
OBJ_DEAD) == 0, ("dead object"));
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;
/* Update node times. */
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;
vm_object_t obj;
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;
if (vp->v_type == VREG) {
obj = node->tn_reg.tn_aobj;
vap->va_bytes = (u_quad_t)obj->resident_page_count * PAGE_SIZE;
} else
vap->va_bytes = node->tn_size;
vap->va_filerev = 0;
return 0;
}
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, 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_read(struct vop_read_args *v)
{
struct vnode *vp;
struct uio *uio;
struct tmpfs_node *node;
vp = v->a_vp;
if (vp->v_type != VREG)
return (EISDIR);
uio = v->a_uio;
if (uio->uio_offset < 0)
return (EINVAL);
node = VP_TO_TMPFS_NODE(vp);
node->tn_status |= TMPFS_NODE_ACCESSED;
return (uiomove_object(node->tn_reg.tn_aobj, node->tn_size, uio));
}
static int
tmpfs_write(struct vop_write_args *v)
{
struct vnode *vp;
struct uio *uio;
struct tmpfs_node *node;
off_t oldsize;
int error, ioflag;
vp = v->a_vp;
uio = v->a_uio;
ioflag = v->a_ioflag;
error = 0;
node = VP_TO_TMPFS_NODE(vp);
oldsize = node->tn_size;
if (uio->uio_offset < 0 || vp->v_type != VREG)
return (EINVAL);
if (uio->uio_resid == 0)
return (0);
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 (vn_rlimit_fsize(vp, uio, uio->uio_td))
return (EFBIG);
if (uio->uio_offset + uio->uio_resid > node->tn_size) {
error = tmpfs_reg_resize(vp, uio->uio_offset + uio->uio_resid,
FALSE);
if (error != 0)
goto out;
}
error = uiomove_object(node->tn_reg.tn_aobj, node->tn_size, uio);
node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED |
TMPFS_NODE_CHANGED;
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, TRUE);
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_check_mtime(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);
if (v->a_cnp->cn_flags & DOWHITEOUT)
tmpfs_dir_whiteout_add(dvp, v->a_cnp);
/* 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);
node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED;
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);
/* 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. */
if (cnp->cn_flags & ISWHITEOUT)
tmpfs_dir_whiteout_remove(dvp, cnp);
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;
}
/*
* We acquire all but fdvp locks using non-blocking acquisitions. If we
* fail to acquire any lock in the path we will drop all held locks,
* acquire the new lock in a blocking fashion, and then release it and
* restart the rename. This acquire/release step ensures that we do not
* spin on a lock waiting for release. On error release all vnode locks
* and decrement references the way tmpfs_rename() would do.
*/
static int
tmpfs_rename_relock(struct vnode *fdvp, struct vnode **fvpp,
struct vnode *tdvp, struct vnode **tvpp,
struct componentname *fcnp, struct componentname *tcnp)
{
struct vnode *nvp;
struct mount *mp;
struct tmpfs_dirent *de;
int error, restarts = 0;
VOP_UNLOCK(tdvp, 0);
if (*tvpp != NULL && *tvpp != tdvp)
VOP_UNLOCK(*tvpp, 0);
mp = fdvp->v_mount;
relock:
restarts += 1;
error = vn_lock(fdvp, LK_EXCLUSIVE);
if (error)
goto releout;
if (vn_lock(tdvp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
VOP_UNLOCK(fdvp, 0);
error = vn_lock(tdvp, LK_EXCLUSIVE);
if (error)
goto releout;
VOP_UNLOCK(tdvp, 0);
goto relock;
}
/*
* Re-resolve fvp to be certain it still exists and fetch the
* correct vnode.
*/
de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(fdvp), NULL, fcnp);
if (de == NULL) {
VOP_UNLOCK(fdvp, 0);
VOP_UNLOCK(tdvp, 0);
if ((fcnp->cn_flags & ISDOTDOT) != 0 ||
(fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.'))
error = EINVAL;
else
error = ENOENT;
goto releout;
}
error = tmpfs_alloc_vp(mp, de->td_node, LK_EXCLUSIVE | LK_NOWAIT, &nvp);
if (error != 0) {
VOP_UNLOCK(fdvp, 0);
VOP_UNLOCK(tdvp, 0);
if (error != EBUSY)
goto releout;
error = tmpfs_alloc_vp(mp, de->td_node, LK_EXCLUSIVE, &nvp);
if (error != 0)
goto releout;
VOP_UNLOCK(nvp, 0);
/*
* Concurrent rename race.
*/
if (nvp == tdvp) {
vrele(nvp);
error = EINVAL;
goto releout;
}
vrele(*fvpp);
*fvpp = nvp;
goto relock;
}
vrele(*fvpp);
*fvpp = nvp;
VOP_UNLOCK(*fvpp, 0);
/*
* Re-resolve tvp and acquire the vnode lock if present.
*/
de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(tdvp), NULL, tcnp);
/*
* If tvp disappeared we just carry on.
*/
if (de == NULL && *tvpp != NULL) {
vrele(*tvpp);
*tvpp = NULL;
}
/*
* Get the tvp ino if the lookup succeeded. We may have to restart
* if the non-blocking acquire fails.
*/
if (de != NULL) {
nvp = NULL;
error = tmpfs_alloc_vp(mp, de->td_node,
LK_EXCLUSIVE | LK_NOWAIT, &nvp);
if (*tvpp != NULL)
vrele(*tvpp);
*tvpp = nvp;
if (error != 0) {
VOP_UNLOCK(fdvp, 0);
VOP_UNLOCK(tdvp, 0);
if (error != EBUSY)
goto releout;
error = tmpfs_alloc_vp(mp, de->td_node, LK_EXCLUSIVE,
&nvp);
if (error != 0)
goto releout;
VOP_UNLOCK(nvp, 0);
/*
* fdvp contains fvp, thus tvp (=fdvp) is not empty.
*/
if (nvp == fdvp) {
error = ENOTEMPTY;
goto releout;
}
goto relock;
}
}
tmpfs_rename_restarts += restarts;
return (0);
releout:
vrele(fdvp);
vrele(*fvpp);
vrele(tdvp);
if (*tvpp != NULL)
vrele(*tvpp);
tmpfs_rename_restarts += restarts;
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;
struct mount *mp = NULL;
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);
/* 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;
}
/* 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 (fdvp != tdvp && fdvp != tvp) {
if (vn_lock(fdvp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
mp = tdvp->v_mount;
error = vfs_busy(mp, 0);
if (error != 0) {
mp = NULL;
goto out;
}
error = tmpfs_rename_relock(fdvp, &fvp, tdvp, &tvp,
fcnp, tcnp);
if (error != 0) {
vfs_unbusy(mp);
return (error);
}
ASSERT_VOP_ELOCKED(fdvp,
"tmpfs_rename: fdvp not locked");
ASSERT_VOP_ELOCKED(tdvp,
"tmpfs_rename: tdvp not locked");
if (tvp != NULL)
ASSERT_VOP_ELOCKED(tvp,
"tmpfs_rename: tvp not locked");
if (fvp == tvp) {
error = 0;
goto out_locked;
}
}
}
tmp = VFS_TO_TMPFS(tdvp->v_mount);
tdnode = VP_TO_TMPFS_DIR(tdvp);
tnode = (tvp == NULL) ? NULL : VP_TO_TMPFS_NODE(tvp);
fdnode = VP_TO_TMPFS_DIR(fdvp);
fnode = VP_TO_TMPFS_NODE(fvp);
de = tmpfs_dir_lookup(fdnode, fnode, fcnp);
/* Entry can disappear before we lock fdvp,
* also avoid manipulating '.' and '..' entries. */
if (de == NULL) {
if ((fcnp->cn_flags & ISDOTDOT) != 0 ||
(fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.'))
error = EINVAL;
else
error = ENOENT;
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);
if (fcnp->cn_flags & DOWHITEOUT)
tmpfs_dir_whiteout_add(fdvp, fcnp);
if (tcnp->cn_flags & ISWHITEOUT)
tmpfs_dir_whiteout_remove(tdvp, tcnp);
/* 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->ud.td_name, M_TMPFSNAME);
de->ud.td_name = newname;
tmpfs_dirent_init(de, tcnp->cn_nameptr, tcnp->cn_namelen);
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) {
struct tmpfs_dirent *tde;
/* Remove the old entry from the target directory. */
tde = tmpfs_dir_lookup(tdnode, tnode, tcnp);
tmpfs_dir_detach(tdvp, tde);
/* 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), tde);
}
tmpfs_dir_attach(tdvp, de);
cache_purge(fvp);
if (tvp != NULL)
cache_purge(tvp);
cache_purge_negative(tdvp);
error = 0;
out_locked:
if (fdvp != tdvp && fdvp != tvp)
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);
if (mp != NULL)
vfs_unbusy(mp);
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);
if (v->a_cnp->cn_flags & DOWHITEOUT)
tmpfs_dir_whiteout_add(dvp, v->a_cnp);
/* 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);
/* 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;
ssize_t startresid;
int maxcookies;
struct tmpfs_node *node;
/* This operation only makes sense on directory nodes. */
if (vp->v_type != VDIR)
return ENOTDIR;
maxcookies = 0;
node = VP_TO_TMPFS_DIR(vp);
startresid = uio->uio_resid;
/* Allocate cookies for NFS and compat modules. */
if (cookies != NULL && ncookies != NULL) {
maxcookies = howmany(node->tn_size,
sizeof(struct tmpfs_dirent)) + 2;
*cookies = malloc(maxcookies * sizeof(**cookies), M_TEMP,
M_WAITOK);
*ncookies = 0;
}
if (cookies == NULL)
error = tmpfs_dir_getdents(node, uio, 0, NULL, NULL);
else
error = tmpfs_dir_getdents(node, uio, maxcookies, *cookies,
ncookies);
/* Buffer was filled without hitting EOF. */
if (error == EJUSTRETURN)
error = (uio->uio_resid != startresid) ? 0 : EINVAL;
if (error != 0 && cookies != NULL && ncookies != NULL) {
free(*cookies, M_TEMP);
*cookies = NULL;
*ncookies = 0;
}
if (eofflag != NULL)
*eofflag =
(error == 0 && uio->uio_offset == TMPFS_DIRCOOKIE_EOF);
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;
struct tmpfs_node *node;
vp = v->a_vp;
node = VP_TO_TMPFS_NODE(vp);
if (node->tn_links == 0)
vrecycle(vp);
else
tmpfs_check_mtime(vp);
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);
if (vp->v_type == VREG)
tmpfs_destroy_vobject(vp, node->tn_reg.tn_aobj);
else
vnode_destroy_vobject(vp);
vp->v_object = NULL;
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%lx, links %d\n",
node, node->tn_flags, node->tn_links);
printf("\tmode 0%o, owner %d, group %d, size %jd, status 0x%x\n",
node->tn_mode, node->tn_uid, node->tn_gid,
(intmax_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);
}
static int
tmpfs_whiteout(struct vop_whiteout_args *ap)
{
struct vnode *dvp = ap->a_dvp;
struct componentname *cnp = ap->a_cnp;
struct tmpfs_dirent *de;
switch (ap->a_flags) {
case LOOKUP:
return (0);
case CREATE:
de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(dvp), NULL, cnp);
if (de != NULL)
return (de->td_node == NULL ? 0 : EEXIST);
return (tmpfs_dir_whiteout_add(dvp, cnp));
case DELETE:
tmpfs_dir_whiteout_remove(dvp, cnp);
return (0);
default:
panic("tmpfs_whiteout: unknown op");
}
}
/*
* 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_whiteout = tmpfs_whiteout,
.vop_bmap = VOP_EOPNOTSUPP,
};
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