FreeBSD-5.3/sys/ufs/ufs/ufs_extattr.c
/*-
* Copyright (c) 1999-2002 Robert N. M. Watson
* Copyright (c) 2002-2003 Networks Associates Technology, Inc.
* All rights reserved.
*
* This software was developed by Robert Watson for the TrustedBSD Project.
*
* This software was developed for the FreeBSD Project in part by Network
* Associates Laboratories, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
* as part of the DARPA CHATS research 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 AUTHOR 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 AUTHOR 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.
*
*/
/*
* Support for filesystem extended attribute: UFS-specific support functions.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/ufs/ufs/ufs_extattr.c,v 1.73 2004/07/12 08:14:09 alfred Exp $");
#include "opt_ufs.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <sys/fcntl.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/lock.h>
#include <sys/dirent.h>
#include <sys/extattr.h>
#include <sys/sysctl.h>
#include <vm/uma.h>
#include <ufs/ufs/dir.h>
#include <ufs/ufs/extattr.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufs_extern.h>
#ifdef UFS_EXTATTR
static MALLOC_DEFINE(M_UFS_EXTATTR, "ufs_extattr", "ufs extended attribute");
static int ufs_extattr_sync = 0;
SYSCTL_INT(_debug, OID_AUTO, ufs_extattr_sync, CTLFLAG_RW, &ufs_extattr_sync,
0, "");
static int ufs_extattr_valid_attrname(int attrnamespace,
const char *attrname);
static int ufs_extattr_enable_with_open(struct ufsmount *ump,
struct vnode *vp, int attrnamespace, const char *attrname,
struct thread *td);
static int ufs_extattr_enable(struct ufsmount *ump, int attrnamespace,
const char *attrname, struct vnode *backing_vnode,
struct thread *td);
static int ufs_extattr_disable(struct ufsmount *ump, int attrnamespace,
const char *attrname, struct thread *td);
static int ufs_extattr_get(struct vnode *vp, int attrnamespace,
const char *name, struct uio *uio, size_t *size,
struct ucred *cred, struct thread *td);
static int ufs_extattr_set(struct vnode *vp, int attrnamespace,
const char *name, struct uio *uio, struct ucred *cred,
struct thread *td);
static int ufs_extattr_rm(struct vnode *vp, int attrnamespace,
const char *name, struct ucred *cred, struct thread *td);
/*
* Per-FS attribute lock protecting attribute operations.
* XXX Right now there is a lot of lock contention due to having a single
* lock per-FS; really, this should be far more fine-grained.
*/
static void
ufs_extattr_uepm_lock(struct ufsmount *ump, struct thread *td)
{
/* Ideally, LK_CANRECURSE would not be used, here. */
lockmgr(&ump->um_extattr.uepm_lock, LK_EXCLUSIVE | LK_RETRY |
LK_CANRECURSE, 0, td);
}
static void
ufs_extattr_uepm_unlock(struct ufsmount *ump, struct thread *td)
{
lockmgr(&ump->um_extattr.uepm_lock, LK_RELEASE, 0, td);
}
/*-
* Determine whether the name passed is a valid name for an actual
* attribute.
*
* Invalid currently consists of:
* NULL pointer for attrname
* zero-length attrname (used to retrieve application attribute list)
*/
static int
ufs_extattr_valid_attrname(int attrnamespace, const char *attrname)
{
if (attrname == NULL)
return (0);
if (strlen(attrname) == 0)
return (0);
return (1);
}
/*
* Locate an attribute given a name and mountpoint.
* Must be holding uepm lock for the mount point.
*/
static struct ufs_extattr_list_entry *
ufs_extattr_find_attr(struct ufsmount *ump, int attrnamespace,
const char *attrname)
{
struct ufs_extattr_list_entry *search_attribute;
for (search_attribute = LIST_FIRST(&ump->um_extattr.uepm_list);
search_attribute != NULL;
search_attribute = LIST_NEXT(search_attribute, uele_entries)) {
if (!(strncmp(attrname, search_attribute->uele_attrname,
UFS_EXTATTR_MAXEXTATTRNAME)) &&
(attrnamespace == search_attribute->uele_attrnamespace)) {
return (search_attribute);
}
}
return (0);
}
/*
* Initialize per-FS structures supporting extended attributes. Do not
* start extended attributes yet.
*/
void
ufs_extattr_uepm_init(struct ufs_extattr_per_mount *uepm)
{
uepm->uepm_flags = 0;
LIST_INIT(&uepm->uepm_list);
/* XXX is PVFS right, here? */
lockinit(&uepm->uepm_lock, PVFS, "extattr", 0, 0);
uepm->uepm_flags |= UFS_EXTATTR_UEPM_INITIALIZED;
}
/*
* Destroy per-FS structures supporting extended attributes. Assumes
* that EAs have already been stopped, and will panic if not.
*/
void
ufs_extattr_uepm_destroy(struct ufs_extattr_per_mount *uepm)
{
if (!(uepm->uepm_flags & UFS_EXTATTR_UEPM_INITIALIZED))
panic("ufs_extattr_uepm_destroy: not initialized");
if ((uepm->uepm_flags & UFS_EXTATTR_UEPM_STARTED))
panic("ufs_extattr_uepm_destroy: called while still started");
/*
* It's not clear that either order for the next two lines is
* ideal, and it should never be a problem if this is only called
* during unmount, and with vfs_busy().
*/
uepm->uepm_flags &= ~UFS_EXTATTR_UEPM_INITIALIZED;
lockdestroy(&uepm->uepm_lock);
}
/*
* Start extended attribute support on an FS.
*/
int
ufs_extattr_start(struct mount *mp, struct thread *td)
{
struct ufsmount *ump;
int error = 0;
ump = VFSTOUFS(mp);
ufs_extattr_uepm_lock(ump, td);
if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_INITIALIZED)) {
error = EOPNOTSUPP;
goto unlock;
}
if (ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED) {
error = EBUSY;
goto unlock;
}
ump->um_extattr.uepm_flags |= UFS_EXTATTR_UEPM_STARTED;
ump->um_extattr.uepm_ucred = crhold(td->td_ucred);
unlock:
ufs_extattr_uepm_unlock(ump, td);
return (error);
}
#ifdef UFS_EXTATTR_AUTOSTART
/*
* Helper routine: given a locked parent directory and filename, return
* the locked vnode of the inode associated with the name. Will not
* follow symlinks, may return any type of vnode. Lock on parent will
* be released even in the event of a failure. In the event that the
* target is the parent (i.e., "."), there will be two references and
* one lock, requiring the caller to possibly special-case.
*/
#define UE_GETDIR_LOCKPARENT 1
#define UE_GETDIR_LOCKPARENT_DONT 2
static int
ufs_extattr_lookup(struct vnode *start_dvp, int lockparent, char *dirname,
struct vnode **vp, struct thread *td)
{
struct vop_cachedlookup_args vargs;
struct componentname cnp;
struct vnode *target_vp;
int error;
bzero(&cnp, sizeof(cnp));
cnp.cn_nameiop = LOOKUP;
cnp.cn_flags = ISLASTCN;
if (lockparent == UE_GETDIR_LOCKPARENT)
cnp.cn_flags |= LOCKPARENT;
cnp.cn_thread = td;
cnp.cn_cred = td->td_ucred;
cnp.cn_pnbuf = uma_zalloc(namei_zone, M_WAITOK);
cnp.cn_nameptr = cnp.cn_pnbuf;
error = copystr(dirname, cnp.cn_pnbuf, MAXPATHLEN,
(size_t *) &cnp.cn_namelen);
if (error) {
if (lockparent == UE_GETDIR_LOCKPARENT_DONT) {
VOP_UNLOCK(start_dvp, 0, td);
}
uma_zfree(namei_zone, cnp.cn_pnbuf);
printf("ufs_extattr_lookup: copystr failed\n");
return (error);
}
cnp.cn_namelen--; /* trim nul termination */
vargs.a_desc = NULL;
vargs.a_dvp = start_dvp;
vargs.a_vpp = &target_vp;
vargs.a_cnp = &cnp;
error = ufs_lookup(&vargs);
uma_zfree(namei_zone, cnp.cn_pnbuf);
if (error) {
/*
* Error condition, may have to release the lock on the parent
* if ufs_lookup() didn't.
*/
if (!(cnp.cn_flags & PDIRUNLOCK) &&
(lockparent == UE_GETDIR_LOCKPARENT_DONT))
VOP_UNLOCK(start_dvp, 0, td);
/*
* Check that ufs_lookup() didn't release the lock when we
* didn't want it to.
*/
if ((cnp.cn_flags & PDIRUNLOCK) &&
(lockparent == UE_GETDIR_LOCKPARENT))
panic("ufs_extattr_lookup: lockparent but PDIRUNLOCK");
return (error);
}
/*
if (target_vp == start_dvp)
panic("ufs_extattr_lookup: target_vp == start_dvp");
*/
if (target_vp != start_dvp &&
!(cnp.cn_flags & PDIRUNLOCK) &&
(lockparent == UE_GETDIR_LOCKPARENT_DONT))
panic("ufs_extattr_lookup: !lockparent but !PDIRUNLOCK");
if ((cnp.cn_flags & PDIRUNLOCK) &&
(lockparent == UE_GETDIR_LOCKPARENT))
panic("ufs_extattr_lookup: lockparent but PDIRUNLOCK");
/* printf("ufs_extattr_lookup: success\n"); */
*vp = target_vp;
return (0);
}
#endif /* !UFS_EXTATTR_AUTOSTART */
/*
* Enable an EA using the passed filesystem, backing vnode, attribute name,
* namespace, and proc. Will perform a VOP_OPEN() on the vp, so expects vp
* to be locked when passed in. The vnode will be returned unlocked,
* regardless of success/failure of the function. As a result, the caller
* will always need to vrele(), but not vput().
*/
static int
ufs_extattr_enable_with_open(struct ufsmount *ump, struct vnode *vp,
int attrnamespace, const char *attrname, struct thread *td)
{
int error;
error = VOP_OPEN(vp, FREAD|FWRITE, td->td_ucred, td, -1);
if (error) {
printf("ufs_extattr_enable_with_open.VOP_OPEN(): failed "
"with %d\n", error);
VOP_UNLOCK(vp, 0, td);
return (error);
}
/*
* XXX: Note, should VOP_CLOSE() if vfs_object_create() fails, but due
* to a similar piece of code in vn_open(), we don't.
*/
if (vn_canvmio(vp) == TRUE)
if ((error = vfs_object_create(vp, td,
td->td_ucred)) != 0) {
/*
* XXX: bug replicated from vn_open(): should
* VOP_CLOSE() here.
*/
VOP_UNLOCK(vp, 0, td);
return (error);
}
vp->v_writecount++;
vref(vp);
VOP_UNLOCK(vp, 0, td);
error = ufs_extattr_enable(ump, attrnamespace, attrname, vp, td);
if (error != 0)
vn_close(vp, FREAD|FWRITE, td->td_ucred, td);
return (error);
}
#ifdef UFS_EXTATTR_AUTOSTART
/*
* Given a locked directory vnode, iterate over the names in the directory
* and use ufs_extattr_lookup() to retrieve locked vnodes of potential
* attribute files. Then invoke ufs_extattr_enable_with_open() on each
* to attempt to start the attribute. Leaves the directory locked on
* exit.
*/
static int
ufs_extattr_iterate_directory(struct ufsmount *ump, struct vnode *dvp,
int attrnamespace, struct thread *td)
{
struct vop_readdir_args vargs;
struct dirent *dp, *edp;
struct vnode *attr_vp;
struct uio auio;
struct iovec aiov;
char *dirbuf;
int error, eofflag = 0;
if (dvp->v_type != VDIR)
return (ENOTDIR);
MALLOC(dirbuf, char *, DIRBLKSIZ, M_TEMP, M_WAITOK);
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_rw = UIO_READ;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_td = td;
auio.uio_offset = 0;
vargs.a_desc = NULL;
vargs.a_vp = dvp;
vargs.a_uio = &auio;
vargs.a_cred = td->td_ucred;
vargs.a_eofflag = &eofflag;
vargs.a_ncookies = NULL;
vargs.a_cookies = NULL;
while (!eofflag) {
auio.uio_resid = DIRBLKSIZ;
aiov.iov_base = dirbuf;
aiov.iov_len = DIRBLKSIZ;
error = ufs_readdir(&vargs);
if (error) {
printf("ufs_extattr_iterate_directory: ufs_readdir "
"%d\n", error);
return (error);
}
/*
* XXXRW: While in UFS, we always get DIRBLKSIZ returns from
* the directory code on success, on other file systems this
* may not be the case. For portability, we should check the
* read length on return from ufs_readdir().
*/
edp = (struct dirent *)&dirbuf[DIRBLKSIZ];
for (dp = (struct dirent *)dirbuf; dp < edp; ) {
#if (BYTE_ORDER == LITTLE_ENDIAN)
dp->d_type = dp->d_namlen;
dp->d_namlen = 0;
#else
dp->d_type = 0;
#endif
if (dp->d_reclen == 0)
break;
error = ufs_extattr_lookup(dvp, UE_GETDIR_LOCKPARENT,
dp->d_name, &attr_vp, td);
if (error) {
printf("ufs_extattr_iterate_directory: lookup "
"%s %d\n", dp->d_name, error);
} else if (attr_vp == dvp) {
vrele(attr_vp);
} else if (attr_vp->v_type != VREG) {
vput(attr_vp);
} else {
error = ufs_extattr_enable_with_open(ump,
attr_vp, attrnamespace, dp->d_name, td);
vrele(attr_vp);
if (error) {
printf("ufs_extattr_iterate_directory: "
"enable %s %d\n", dp->d_name,
error);
} else if (bootverbose) {
printf("UFS autostarted EA %s\n",
dp->d_name);
}
}
dp = (struct dirent *) ((char *)dp + dp->d_reclen);
if (dp >= edp)
break;
}
}
FREE(dirbuf, M_TEMP);
return (0);
}
/*
* Auto-start of extended attributes, to be executed (optionally) at
* mount-time.
*/
int
ufs_extattr_autostart(struct mount *mp, struct thread *td)
{
struct vnode *rvp, *attr_dvp, *attr_system_dvp, *attr_user_dvp;
int error;
/*
* Does UFS_EXTATTR_FSROOTSUBDIR exist off the filesystem root?
* If so, automatically start EA's.
*/
error = VFS_ROOT(mp, &rvp, td);
if (error) {
printf("ufs_extattr_autostart.VFS_ROOT() returned %d\n",
error);
return (error);
}
error = ufs_extattr_lookup(rvp, UE_GETDIR_LOCKPARENT_DONT,
UFS_EXTATTR_FSROOTSUBDIR, &attr_dvp, td);
if (error) {
/* rvp ref'd but now unlocked */
vrele(rvp);
return (error);
}
if (rvp == attr_dvp) {
/* Should never happen. */
vrele(attr_dvp);
vput(rvp);
return (EINVAL);
}
vrele(rvp);
if (attr_dvp->v_type != VDIR) {
printf("ufs_extattr_autostart: %s != VDIR\n",
UFS_EXTATTR_FSROOTSUBDIR);
goto return_vput_attr_dvp;
}
error = ufs_extattr_start(mp, td);
if (error) {
printf("ufs_extattr_autostart: ufs_extattr_start failed (%d)\n",
error);
goto return_vput_attr_dvp;
}
/*
* Look for two subdirectories: UFS_EXTATTR_SUBDIR_SYSTEM,
* UFS_EXTATTR_SUBDIR_USER. For each, iterate over the sub-directory,
* and start with appropriate type. Failures in either don't
* result in an over-all failure. attr_dvp is left locked to
* be cleaned up on exit.
*/
error = ufs_extattr_lookup(attr_dvp, UE_GETDIR_LOCKPARENT,
UFS_EXTATTR_SUBDIR_SYSTEM, &attr_system_dvp, td);
if (!error) {
error = ufs_extattr_iterate_directory(VFSTOUFS(mp),
attr_system_dvp, EXTATTR_NAMESPACE_SYSTEM, td);
if (error)
printf("ufs_extattr_iterate_directory returned %d\n",
error);
vput(attr_system_dvp);
}
error = ufs_extattr_lookup(attr_dvp, UE_GETDIR_LOCKPARENT,
UFS_EXTATTR_SUBDIR_USER, &attr_user_dvp, td);
if (!error) {
error = ufs_extattr_iterate_directory(VFSTOUFS(mp),
attr_user_dvp, EXTATTR_NAMESPACE_USER, td);
if (error)
printf("ufs_extattr_iterate_directory returned %d\n",
error);
vput(attr_user_dvp);
}
/* Mask startup failures in sub-directories. */
error = 0;
return_vput_attr_dvp:
vput(attr_dvp);
return (error);
}
#endif /* !UFS_EXTATTR_AUTOSTART */
/*
* Stop extended attribute support on an FS.
*/
int
ufs_extattr_stop(struct mount *mp, struct thread *td)
{
struct ufs_extattr_list_entry *uele;
struct ufsmount *ump = VFSTOUFS(mp);
int error = 0;
ufs_extattr_uepm_lock(ump, td);
if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) {
error = EOPNOTSUPP;
goto unlock;
}
while (LIST_FIRST(&ump->um_extattr.uepm_list) != NULL) {
uele = LIST_FIRST(&ump->um_extattr.uepm_list);
ufs_extattr_disable(ump, uele->uele_attrnamespace,
uele->uele_attrname, td);
}
ump->um_extattr.uepm_flags &= ~UFS_EXTATTR_UEPM_STARTED;
crfree(ump->um_extattr.uepm_ucred);
ump->um_extattr.uepm_ucred = NULL;
unlock:
ufs_extattr_uepm_unlock(ump, td);
return (error);
}
/*
* Enable a named attribute on the specified filesystem; provide an
* unlocked backing vnode to hold the attribute data.
*/
static int
ufs_extattr_enable(struct ufsmount *ump, int attrnamespace,
const char *attrname, struct vnode *backing_vnode, struct thread *td)
{
struct ufs_extattr_list_entry *attribute;
struct iovec aiov;
struct uio auio;
int error = 0;
if (!ufs_extattr_valid_attrname(attrnamespace, attrname))
return (EINVAL);
if (backing_vnode->v_type != VREG)
return (EINVAL);
MALLOC(attribute, struct ufs_extattr_list_entry *,
sizeof(struct ufs_extattr_list_entry), M_UFS_EXTATTR, M_WAITOK);
if (attribute == NULL)
return (ENOMEM);
if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) {
error = EOPNOTSUPP;
goto free_exit;
}
if (ufs_extattr_find_attr(ump, attrnamespace, attrname)) {
error = EEXIST;
goto free_exit;
}
strncpy(attribute->uele_attrname, attrname,
UFS_EXTATTR_MAXEXTATTRNAME);
attribute->uele_attrnamespace = attrnamespace;
bzero(&attribute->uele_fileheader,
sizeof(struct ufs_extattr_fileheader));
attribute->uele_backing_vnode = backing_vnode;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
aiov.iov_base = (caddr_t) &attribute->uele_fileheader;
aiov.iov_len = sizeof(struct ufs_extattr_fileheader);
auio.uio_resid = sizeof(struct ufs_extattr_fileheader);
auio.uio_offset = (off_t) 0;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_rw = UIO_READ;
auio.uio_td = td;
VOP_LEASE(backing_vnode, td, td->td_ucred, LEASE_WRITE);
vn_lock(backing_vnode, LK_SHARED | LK_NOPAUSE | LK_RETRY, td);
error = VOP_READ(backing_vnode, &auio, IO_NODELOCKED,
ump->um_extattr.uepm_ucred);
if (error)
goto unlock_free_exit;
if (auio.uio_resid != 0) {
printf("ufs_extattr_enable: malformed attribute header\n");
error = EINVAL;
goto unlock_free_exit;
}
if (attribute->uele_fileheader.uef_magic != UFS_EXTATTR_MAGIC) {
printf("ufs_extattr_enable: invalid attribute header magic\n");
error = EINVAL;
goto unlock_free_exit;
}
if (attribute->uele_fileheader.uef_version != UFS_EXTATTR_VERSION) {
printf("ufs_extattr_enable: incorrect attribute header "
"version\n");
error = EINVAL;
goto unlock_free_exit;
}
ASSERT_VOP_LOCKED(backing_vnode, "ufs_extattr_enable");
LIST_INSERT_HEAD(&ump->um_extattr.uepm_list, attribute,
uele_entries);
VOP_UNLOCK(backing_vnode, 0, td);
return (0);
unlock_free_exit:
VOP_UNLOCK(backing_vnode, 0, td);
free_exit:
FREE(attribute, M_UFS_EXTATTR);
return (error);
}
/*
* Disable extended attribute support on an FS.
*/
static int
ufs_extattr_disable(struct ufsmount *ump, int attrnamespace,
const char *attrname, struct thread *td)
{
struct ufs_extattr_list_entry *uele;
int error = 0;
if (!ufs_extattr_valid_attrname(attrnamespace, attrname))
return (EINVAL);
uele = ufs_extattr_find_attr(ump, attrnamespace, attrname);
if (!uele)
return (ENOATTR);
LIST_REMOVE(uele, uele_entries);
vn_lock(uele->uele_backing_vnode, LK_SHARED | LK_NOPAUSE | LK_RETRY,
td);
ASSERT_VOP_LOCKED(uele->uele_backing_vnode, "ufs_extattr_disable");
VOP_UNLOCK(uele->uele_backing_vnode, 0, td);
error = vn_close(uele->uele_backing_vnode, FREAD|FWRITE,
td->td_ucred, td);
FREE(uele, M_UFS_EXTATTR);
return (error);
}
/*
* VFS call to manage extended attributes in UFS. If filename_vp is
* non-NULL, it must be passed in locked, and regardless of errors in
* processing, will be unlocked.
*/
int
ufs_extattrctl(struct mount *mp, int cmd, struct vnode *filename_vp,
int attrnamespace, const char *attrname, struct thread *td)
{
struct ufsmount *ump = VFSTOUFS(mp);
int error;
/*
* Processes with privilege, but in jail, are not allowed to
* configure extended attributes.
*/
if ((error = suser(td))) {
if (filename_vp != NULL)
VOP_UNLOCK(filename_vp, 0, td);
return (error);
}
switch(cmd) {
case UFS_EXTATTR_CMD_START:
if (filename_vp != NULL) {
VOP_UNLOCK(filename_vp, 0, td);
return (EINVAL);
}
if (attrname != NULL)
return (EINVAL);
error = ufs_extattr_start(mp, td);
return (error);
case UFS_EXTATTR_CMD_STOP:
if (filename_vp != NULL) {
VOP_UNLOCK(filename_vp, 0, td);
return (EINVAL);
}
if (attrname != NULL)
return (EINVAL);
error = ufs_extattr_stop(mp, td);
return (error);
case UFS_EXTATTR_CMD_ENABLE:
if (filename_vp == NULL)
return (EINVAL);
if (attrname == NULL) {
VOP_UNLOCK(filename_vp, 0, td);
return (EINVAL);
}
/*
* ufs_extattr_enable_with_open() will always unlock the
* vnode, regardless of failure.
*/
ufs_extattr_uepm_lock(ump, td);
error = ufs_extattr_enable_with_open(ump, filename_vp,
attrnamespace, attrname, td);
ufs_extattr_uepm_unlock(ump, td);
return (error);
case UFS_EXTATTR_CMD_DISABLE:
if (filename_vp != NULL) {
VOP_UNLOCK(filename_vp, 0, td);
return (EINVAL);
}
if (attrname == NULL)
return (EINVAL);
ufs_extattr_uepm_lock(ump, td);
error = ufs_extattr_disable(ump, attrnamespace, attrname,
td);
ufs_extattr_uepm_unlock(ump, td);
return (error);
default:
return (EINVAL);
}
}
/*
* Vnode operating to retrieve a named extended attribute.
*/
int
ufs_getextattr(struct vop_getextattr_args *ap)
/*
vop_getextattr {
IN struct vnode *a_vp;
IN int a_attrnamespace;
IN const char *a_name;
INOUT struct uio *a_uio;
OUT size_t *a_size;
IN struct ucred *a_cred;
IN struct thread *a_td;
};
*/
{
struct mount *mp = ap->a_vp->v_mount;
struct ufsmount *ump = VFSTOUFS(mp);
int error;
ufs_extattr_uepm_lock(ump, ap->a_td);
error = ufs_extattr_get(ap->a_vp, ap->a_attrnamespace, ap->a_name,
ap->a_uio, ap->a_size, ap->a_cred, ap->a_td);
ufs_extattr_uepm_unlock(ump, ap->a_td);
return (error);
}
/*
* Real work associated with retrieving a named attribute--assumes that
* the attribute lock has already been grabbed.
*/
static int
ufs_extattr_get(struct vnode *vp, int attrnamespace, const char *name,
struct uio *uio, size_t *size, struct ucred *cred, struct thread *td)
{
struct ufs_extattr_list_entry *attribute;
struct ufs_extattr_header ueh;
struct iovec local_aiov;
struct uio local_aio;
struct mount *mp = vp->v_mount;
struct ufsmount *ump = VFSTOUFS(mp);
struct inode *ip = VTOI(vp);
off_t base_offset;
size_t len, old_len;
int error = 0;
if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED))
return (EOPNOTSUPP);
if (strlen(name) == 0)
return (EINVAL);
error = extattr_check_cred(vp, attrnamespace, cred, td, IREAD);
if (error)
return (error);
attribute = ufs_extattr_find_attr(ump, attrnamespace, name);
if (!attribute)
return (ENOATTR);
/*
* Allow only offsets of zero to encourage the read/replace
* extended attribute semantic. Otherwise we can't guarantee
* atomicity, as we don't provide locks for extended attributes.
*/
if (uio != NULL && uio->uio_offset != 0)
return (ENXIO);
/*
* Find base offset of header in file based on file header size, and
* data header size + maximum data size, indexed by inode number.
*/
base_offset = sizeof(struct ufs_extattr_fileheader) +
ip->i_number * (sizeof(struct ufs_extattr_header) +
attribute->uele_fileheader.uef_size);
/*
* Read in the data header to see if the data is defined, and if so
* how much.
*/
bzero(&ueh, sizeof(struct ufs_extattr_header));
local_aiov.iov_base = (caddr_t) &ueh;
local_aiov.iov_len = sizeof(struct ufs_extattr_header);
local_aio.uio_iov = &local_aiov;
local_aio.uio_iovcnt = 1;
local_aio.uio_rw = UIO_READ;
local_aio.uio_segflg = UIO_SYSSPACE;
local_aio.uio_td = td;
local_aio.uio_offset = base_offset;
local_aio.uio_resid = sizeof(struct ufs_extattr_header);
/*
* Acquire locks.
*/
VOP_LEASE(attribute->uele_backing_vnode, td, cred, LEASE_READ);
/*
* Don't need to get a lock on the backing file if the getattr is
* being applied to the backing file, as the lock is already held.
*/
if (attribute->uele_backing_vnode != vp)
vn_lock(attribute->uele_backing_vnode, LK_SHARED |
LK_NOPAUSE | LK_RETRY, td);
error = VOP_READ(attribute->uele_backing_vnode, &local_aio,
IO_NODELOCKED, ump->um_extattr.uepm_ucred);
if (error)
goto vopunlock_exit;
/* Defined? */
if ((ueh.ueh_flags & UFS_EXTATTR_ATTR_FLAG_INUSE) == 0) {
error = ENOATTR;
goto vopunlock_exit;
}
/* Valid for the current inode generation? */
if (ueh.ueh_i_gen != ip->i_gen) {
/*
* The inode itself has a different generation number
* than the attribute data. For now, the best solution
* is to coerce this to undefined, and let it get cleaned
* up by the next write or extattrctl clean.
*/
printf("ufs_extattr_get (%s): inode number inconsistency (%d, %jd)\n",
mp->mnt_stat.f_mntonname, ueh.ueh_i_gen, (intmax_t)ip->i_gen);
error = ENOATTR;
goto vopunlock_exit;
}
/* Local size consistency check. */
if (ueh.ueh_len > attribute->uele_fileheader.uef_size) {
error = ENXIO;
goto vopunlock_exit;
}
/* Return full data size if caller requested it. */
if (size != NULL)
*size = ueh.ueh_len;
/* Return data if the caller requested it. */
if (uio != NULL) {
/* Allow for offset into the attribute data. */
uio->uio_offset = base_offset + sizeof(struct
ufs_extattr_header);
/*
* Figure out maximum to transfer -- use buffer size and
* local data limit.
*/
len = MIN(uio->uio_resid, ueh.ueh_len);
old_len = uio->uio_resid;
uio->uio_resid = len;
error = VOP_READ(attribute->uele_backing_vnode, uio,
IO_NODELOCKED, ump->um_extattr.uepm_ucred);
if (error)
goto vopunlock_exit;
uio->uio_resid = old_len - (len - uio->uio_resid);
}
vopunlock_exit:
if (uio != NULL)
uio->uio_offset = 0;
if (attribute->uele_backing_vnode != vp)
VOP_UNLOCK(attribute->uele_backing_vnode, 0, td);
return (error);
}
/*
* Vnode operation to remove a named attribute.
*/
int
ufs_deleteextattr(struct vop_deleteextattr_args *ap)
/*
vop_deleteextattr {
IN struct vnode *a_vp;
IN int a_attrnamespace;
IN const char *a_name;
IN struct ucred *a_cred;
IN struct thread *a_td;
};
*/
{
struct mount *mp = ap->a_vp->v_mount;
struct ufsmount *ump = VFSTOUFS(mp);
int error;
ufs_extattr_uepm_lock(ump, ap->a_td);
error = ufs_extattr_rm(ap->a_vp, ap->a_attrnamespace, ap->a_name,
ap->a_cred, ap->a_td);
ufs_extattr_uepm_unlock(ump, ap->a_td);
return (error);
}
/*
* Vnode operation to set a named attribute.
*/
int
ufs_setextattr(struct vop_setextattr_args *ap)
/*
vop_setextattr {
IN struct vnode *a_vp;
IN int a_attrnamespace;
IN const char *a_name;
INOUT struct uio *a_uio;
IN struct ucred *a_cred;
IN struct thread *a_td;
};
*/
{
struct mount *mp = ap->a_vp->v_mount;
struct ufsmount *ump = VFSTOUFS(mp);
int error;
ufs_extattr_uepm_lock(ump, ap->a_td);
/*
* XXX: No longer a supported way to delete extended attributes.
*/
if (ap->a_uio == NULL)
return (EINVAL);
error = ufs_extattr_set(ap->a_vp, ap->a_attrnamespace, ap->a_name,
ap->a_uio, ap->a_cred, ap->a_td);
ufs_extattr_uepm_unlock(ump, ap->a_td);
return (error);
}
/*
* Real work associated with setting a vnode's extended attributes;
* assumes that the attribute lock has already been grabbed.
*/
static int
ufs_extattr_set(struct vnode *vp, int attrnamespace, const char *name,
struct uio *uio, struct ucred *cred, struct thread *td)
{
struct ufs_extattr_list_entry *attribute;
struct ufs_extattr_header ueh;
struct iovec local_aiov;
struct uio local_aio;
struct mount *mp = vp->v_mount;
struct ufsmount *ump = VFSTOUFS(mp);
struct inode *ip = VTOI(vp);
off_t base_offset;
int error = 0, ioflag;
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return (EROFS);
if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED))
return (EOPNOTSUPP);
if (!ufs_extattr_valid_attrname(attrnamespace, name))
return (EINVAL);
error = extattr_check_cred(vp, attrnamespace, cred, td, IWRITE);
if (error)
return (error);
attribute = ufs_extattr_find_attr(ump, attrnamespace, name);
if (!attribute)
return (ENOATTR);
/*
* Early rejection of invalid offsets/length.
* Reject: any offset but 0 (replace)
* Any size greater than attribute size limit
*/
if (uio->uio_offset != 0 ||
uio->uio_resid > attribute->uele_fileheader.uef_size)
return (ENXIO);
/*
* Find base offset of header in file based on file header size, and
* data header size + maximum data size, indexed by inode number.
*/
base_offset = sizeof(struct ufs_extattr_fileheader) +
ip->i_number * (sizeof(struct ufs_extattr_header) +
attribute->uele_fileheader.uef_size);
/*
* Write out a data header for the data.
*/
ueh.ueh_len = uio->uio_resid;
ueh.ueh_flags = UFS_EXTATTR_ATTR_FLAG_INUSE;
ueh.ueh_i_gen = ip->i_gen;
local_aiov.iov_base = (caddr_t) &ueh;
local_aiov.iov_len = sizeof(struct ufs_extattr_header);
local_aio.uio_iov = &local_aiov;
local_aio.uio_iovcnt = 1;
local_aio.uio_rw = UIO_WRITE;
local_aio.uio_segflg = UIO_SYSSPACE;
local_aio.uio_td = td;
local_aio.uio_offset = base_offset;
local_aio.uio_resid = sizeof(struct ufs_extattr_header);
/*
* Acquire locks.
*/
VOP_LEASE(attribute->uele_backing_vnode, td, cred, LEASE_WRITE);
/*
* Don't need to get a lock on the backing file if the setattr is
* being applied to the backing file, as the lock is already held.
*/
if (attribute->uele_backing_vnode != vp)
vn_lock(attribute->uele_backing_vnode,
LK_EXCLUSIVE | LK_NOPAUSE | LK_RETRY, td);
ioflag = IO_NODELOCKED;
if (ufs_extattr_sync)
ioflag |= IO_SYNC;
error = VOP_WRITE(attribute->uele_backing_vnode, &local_aio, ioflag,
ump->um_extattr.uepm_ucred);
if (error)
goto vopunlock_exit;
if (local_aio.uio_resid != 0) {
error = ENXIO;
goto vopunlock_exit;
}
/*
* Write out user data.
*/
uio->uio_offset = base_offset + sizeof(struct ufs_extattr_header);
ioflag = IO_NODELOCKED;
if (ufs_extattr_sync)
ioflag |= IO_SYNC;
error = VOP_WRITE(attribute->uele_backing_vnode, uio, ioflag,
ump->um_extattr.uepm_ucred);
vopunlock_exit:
uio->uio_offset = 0;
if (attribute->uele_backing_vnode != vp)
VOP_UNLOCK(attribute->uele_backing_vnode, 0, td);
return (error);
}
/*
* Real work associated with removing an extended attribute from a vnode.
* Assumes the attribute lock has already been grabbed.
*/
static int
ufs_extattr_rm(struct vnode *vp, int attrnamespace, const char *name,
struct ucred *cred, struct thread *td)
{
struct ufs_extattr_list_entry *attribute;
struct ufs_extattr_header ueh;
struct iovec local_aiov;
struct uio local_aio;
struct mount *mp = vp->v_mount;
struct ufsmount *ump = VFSTOUFS(mp);
struct inode *ip = VTOI(vp);
off_t base_offset;
int error = 0, ioflag;
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return (EROFS);
if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED))
return (EOPNOTSUPP);
if (!ufs_extattr_valid_attrname(attrnamespace, name))
return (EINVAL);
error = extattr_check_cred(vp, attrnamespace, cred, td, IWRITE);
if (error)
return (error);
attribute = ufs_extattr_find_attr(ump, attrnamespace, name);
if (!attribute)
return (ENOATTR);
/*
* Find base offset of header in file based on file header size, and
* data header size + maximum data size, indexed by inode number.
*/
base_offset = sizeof(struct ufs_extattr_fileheader) +
ip->i_number * (sizeof(struct ufs_extattr_header) +
attribute->uele_fileheader.uef_size);
/*
* Check to see if currently defined.
*/
bzero(&ueh, sizeof(struct ufs_extattr_header));
local_aiov.iov_base = (caddr_t) &ueh;
local_aiov.iov_len = sizeof(struct ufs_extattr_header);
local_aio.uio_iov = &local_aiov;
local_aio.uio_iovcnt = 1;
local_aio.uio_rw = UIO_READ;
local_aio.uio_segflg = UIO_SYSSPACE;
local_aio.uio_td = td;
local_aio.uio_offset = base_offset;
local_aio.uio_resid = sizeof(struct ufs_extattr_header);
VOP_LEASE(attribute->uele_backing_vnode, td, cred, LEASE_WRITE);
/*
* Don't need to get the lock on the backing vnode if the vnode we're
* modifying is it, as we already hold the lock.
*/
if (attribute->uele_backing_vnode != vp)
vn_lock(attribute->uele_backing_vnode,
LK_EXCLUSIVE | LK_NOPAUSE | LK_RETRY, td);
error = VOP_READ(attribute->uele_backing_vnode, &local_aio,
IO_NODELOCKED, ump->um_extattr.uepm_ucred);
if (error)
goto vopunlock_exit;
/* Defined? */
if ((ueh.ueh_flags & UFS_EXTATTR_ATTR_FLAG_INUSE) == 0) {
error = ENOATTR;
goto vopunlock_exit;
}
/* Valid for the current inode generation? */
if (ueh.ueh_i_gen != ip->i_gen) {
/*
* The inode itself has a different generation number than
* the attribute data. For now, the best solution is to
* coerce this to undefined, and let it get cleaned up by
* the next write or extattrctl clean.
*/
printf("ufs_extattr_rm (%s): inode number inconsistency (%d, %jd)\n",
mp->mnt_stat.f_mntonname, ueh.ueh_i_gen, (intmax_t)ip->i_gen);
error = ENOATTR;
goto vopunlock_exit;
}
/* Flag it as not in use. */
ueh.ueh_flags = 0;
ueh.ueh_len = 0;
local_aiov.iov_base = (caddr_t) &ueh;
local_aiov.iov_len = sizeof(struct ufs_extattr_header);
local_aio.uio_iov = &local_aiov;
local_aio.uio_iovcnt = 1;
local_aio.uio_rw = UIO_WRITE;
local_aio.uio_segflg = UIO_SYSSPACE;
local_aio.uio_td = td;
local_aio.uio_offset = base_offset;
local_aio.uio_resid = sizeof(struct ufs_extattr_header);
ioflag = IO_NODELOCKED;
if (ufs_extattr_sync)
ioflag |= IO_SYNC;
error = VOP_WRITE(attribute->uele_backing_vnode, &local_aio, ioflag,
ump->um_extattr.uepm_ucred);
if (error)
goto vopunlock_exit;
if (local_aio.uio_resid != 0)
error = ENXIO;
vopunlock_exit:
VOP_UNLOCK(attribute->uele_backing_vnode, 0, td);
return (error);
}
/*
* Called by UFS when an inode is no longer active and should have its
* attributes stripped.
*/
void
ufs_extattr_vnode_inactive(struct vnode *vp, struct thread *td)
{
struct ufs_extattr_list_entry *uele;
struct mount *mp = vp->v_mount;
struct ufsmount *ump = VFSTOUFS(mp);
/*
* In that case, we cannot lock. We should not have any active vnodes
* on the fs if this is not yet initialized but is going to be, so
* this can go unlocked.
*/
if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_INITIALIZED))
return;
ufs_extattr_uepm_lock(ump, td);
if (!(ump->um_extattr.uepm_flags & UFS_EXTATTR_UEPM_STARTED)) {
ufs_extattr_uepm_unlock(ump, td);
return;
}
LIST_FOREACH(uele, &ump->um_extattr.uepm_list, uele_entries)
ufs_extattr_rm(vp, uele->uele_attrnamespace,
uele->uele_attrname, NULL, td);
ufs_extattr_uepm_unlock(ump, td);
}
#endif /* !UFS_EXTATTR */