p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity
linux_old1/fs/xfs/xfs_ioctl.c

1630 lines
36 KiB
C
Raw Blame History

/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_alloc.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_ioctl.h"
#include "xfs_rtalloc.h"
#include "xfs_itable.h"
#include "xfs_error.h"
#include "xfs_attr.h"
#include "xfs_bmap.h"
#include "xfs_buf_item.h"
#include "xfs_utils.h"
#include "xfs_dfrag.h"
#include "xfs_fsops.h"
#include "xfs_vnodeops.h"
#include "xfs_discard.h"
#include "xfs_quota.h"
#include "xfs_inode_item.h"
#include "xfs_export.h"
#include "xfs_trace.h"
#include "xfs_icache.h"
#include <linux/capability.h>
#include <linux/dcache.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/exportfs.h>
/*
* xfs_find_handle maps from userspace xfs_fsop_handlereq structure to
* a file or fs handle.
*
* XFS_IOC_PATH_TO_FSHANDLE
* returns fs handle for a mount point or path within that mount point
* XFS_IOC_FD_TO_HANDLE
* returns full handle for a FD opened in user space
* XFS_IOC_PATH_TO_HANDLE
* returns full handle for a path
*/
int
xfs_find_handle(
unsigned int cmd,
xfs_fsop_handlereq_t *hreq)
{
int hsize;
xfs_handle_t handle;
struct inode *inode;
struct fd f = {0};
struct path path;
int error;
struct xfs_inode *ip;
if (cmd == XFS_IOC_FD_TO_HANDLE) {
f = fdget(hreq->fd);
if (!f.file)
return -EBADF;
inode = file_inode(f.file);
} else {
error = user_lpath((const char __user *)hreq->path, &path);
if (error)
return error;
inode = path.dentry->d_inode;
}
ip = XFS_I(inode);
/*
* We can only generate handles for inodes residing on a XFS filesystem,
* and only for regular files, directories or symbolic links.
*/
error = -EINVAL;
if (inode->i_sb->s_magic != XFS_SB_MAGIC)
goto out_put;
error = -EBADF;
if (!S_ISREG(inode->i_mode) &&
!S_ISDIR(inode->i_mode) &&
!S_ISLNK(inode->i_mode))
goto out_put;
memcpy(&handle.ha_fsid, ip->i_mount->m_fixedfsid, sizeof(xfs_fsid_t));
if (cmd == XFS_IOC_PATH_TO_FSHANDLE) {
/*
* This handle only contains an fsid, zero the rest.
*/
memset(&handle.ha_fid, 0, sizeof(handle.ha_fid));
hsize = sizeof(xfs_fsid_t);
} else {
int lock_mode;
lock_mode = xfs_ilock_map_shared(ip);
handle.ha_fid.fid_len = sizeof(xfs_fid_t) -
sizeof(handle.ha_fid.fid_len);
handle.ha_fid.fid_pad = 0;
handle.ha_fid.fid_gen = ip->i_d.di_gen;
handle.ha_fid.fid_ino = ip->i_ino;
xfs_iunlock_map_shared(ip, lock_mode);
hsize = XFS_HSIZE(handle);
}
error = -EFAULT;
if (copy_to_user(hreq->ohandle, &handle, hsize) ||
copy_to_user(hreq->ohandlen, &hsize, sizeof(__s32)))
goto out_put;
error = 0;
out_put:
if (cmd == XFS_IOC_FD_TO_HANDLE)
fdput(f);
else
path_put(&path);
return error;
}
/*
* No need to do permission checks on the various pathname components
* as the handle operations are privileged.
*/
STATIC int
xfs_handle_acceptable(
void *context,
struct dentry *dentry)
{
return 1;
}
/*
* Convert userspace handle data into a dentry.
*/
struct dentry *
xfs_handle_to_dentry(
struct file *parfilp,
void __user *uhandle,
u32 hlen)
{
xfs_handle_t handle;
struct xfs_fid64 fid;
/*
* Only allow handle opens under a directory.
*/
if (!S_ISDIR(file_inode(parfilp)->i_mode))
return ERR_PTR(-ENOTDIR);
if (hlen != sizeof(xfs_handle_t))
return ERR_PTR(-EINVAL);
if (copy_from_user(&handle, uhandle, hlen))
return ERR_PTR(-EFAULT);
if (handle.ha_fid.fid_len !=
sizeof(handle.ha_fid) - sizeof(handle.ha_fid.fid_len))
return ERR_PTR(-EINVAL);
memset(&fid, 0, sizeof(struct fid));
fid.ino = handle.ha_fid.fid_ino;
fid.gen = handle.ha_fid.fid_gen;
return exportfs_decode_fh(parfilp->f_path.mnt, (struct fid *)&fid, 3,
FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG,
xfs_handle_acceptable, NULL);
}
STATIC struct dentry *
xfs_handlereq_to_dentry(
struct file *parfilp,
xfs_fsop_handlereq_t *hreq)
{
return xfs_handle_to_dentry(parfilp, hreq->ihandle, hreq->ihandlen);
}
int
xfs_open_by_handle(
struct file *parfilp,
xfs_fsop_handlereq_t *hreq)
{
const struct cred *cred = current_cred();
int error;
int fd;
int permflag;
struct file *filp;
struct inode *inode;
struct dentry *dentry;
fmode_t fmode;
struct path path;
if (!capable(CAP_SYS_ADMIN))
return -XFS_ERROR(EPERM);
dentry = xfs_handlereq_to_dentry(parfilp, hreq);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
inode = dentry->d_inode;
/* Restrict xfs_open_by_handle to directories & regular files. */
if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))) {
error = -XFS_ERROR(EPERM);
goto out_dput;
}
#if BITS_PER_LONG != 32
hreq->oflags |= O_LARGEFILE;
#endif
permflag = hreq->oflags;
fmode = OPEN_FMODE(permflag);
if ((!(permflag & O_APPEND) || (permflag & O_TRUNC)) &&
(fmode & FMODE_WRITE) && IS_APPEND(inode)) {
error = -XFS_ERROR(EPERM);
goto out_dput;
}
if ((fmode & FMODE_WRITE) && IS_IMMUTABLE(inode)) {
error = -XFS_ERROR(EACCES);
goto out_dput;
}
/* Can't write directories. */
if (S_ISDIR(inode->i_mode) && (fmode & FMODE_WRITE)) {
error = -XFS_ERROR(EISDIR);
goto out_dput;
}
fd = get_unused_fd();
if (fd < 0) {
error = fd;
goto out_dput;
}
path.mnt = parfilp->f_path.mnt;
path.dentry = dentry;
filp = dentry_open(&path, hreq->oflags, cred);
dput(dentry);
if (IS_ERR(filp)) {
put_unused_fd(fd);
return PTR_ERR(filp);
}
if (S_ISREG(inode->i_mode)) {
filp->f_flags |= O_NOATIME;
filp->f_mode |= FMODE_NOCMTIME;
}
fd_install(fd, filp);
return fd;
out_dput:
dput(dentry);
return error;
}
/*
* This is a copy from fs/namei.c:vfs_readlink(), except for removing it's
* unused first argument.
*/
STATIC int
do_readlink(
char __user *buffer,
int buflen,
const char *link)
{
int len;
len = PTR_ERR(link);
if (IS_ERR(link))
goto out;
len = strlen(link);
if (len > (unsigned) buflen)
len = buflen;
if (copy_to_user(buffer, link, len))
len = -EFAULT;
out:
return len;
}
int
xfs_readlink_by_handle(
struct file *parfilp,
xfs_fsop_handlereq_t *hreq)
{
struct dentry *dentry;
__u32 olen;
void *link;
int error;
if (!capable(CAP_SYS_ADMIN))
return -XFS_ERROR(EPERM);
dentry = xfs_handlereq_to_dentry(parfilp, hreq);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
/* Restrict this handle operation to symlinks only. */
if (!S_ISLNK(dentry->d_inode->i_mode)) {
error = -XFS_ERROR(EINVAL);
goto out_dput;
}
if (copy_from_user(&olen, hreq->ohandlen, sizeof(__u32))) {
error = -XFS_ERROR(EFAULT);
goto out_dput;
}
link = kmalloc(MAXPATHLEN+1, GFP_KERNEL);
if (!link) {
error = -XFS_ERROR(ENOMEM);
goto out_dput;
}
error = -xfs_readlink(XFS_I(dentry->d_inode), link);
if (error)
goto out_kfree;
error = do_readlink(hreq->ohandle, olen, link);
if (error)
goto out_kfree;
out_kfree:
kfree(link);
out_dput:
dput(dentry);
return error;
}
STATIC int
xfs_fssetdm_by_handle(
struct file *parfilp,
void __user *arg)
{
int error;
struct fsdmidata fsd;
xfs_fsop_setdm_handlereq_t dmhreq;
struct dentry *dentry;
if (!capable(CAP_MKNOD))
return -XFS_ERROR(EPERM);
if (copy_from_user(&dmhreq, arg, sizeof(xfs_fsop_setdm_handlereq_t)))
return -XFS_ERROR(EFAULT);
error = mnt_want_write_file(parfilp);
if (error)
return error;
dentry = xfs_handlereq_to_dentry(parfilp, &dmhreq.hreq);
if (IS_ERR(dentry)) {
mnt_drop_write_file(parfilp);
return PTR_ERR(dentry);
}
if (IS_IMMUTABLE(dentry->d_inode) || IS_APPEND(dentry->d_inode)) {
error = -XFS_ERROR(EPERM);
goto out;
}
if (copy_from_user(&fsd, dmhreq.data, sizeof(fsd))) {
error = -XFS_ERROR(EFAULT);
goto out;
}
error = -xfs_set_dmattrs(XFS_I(dentry->d_inode), fsd.fsd_dmevmask,
fsd.fsd_dmstate);
out:
mnt_drop_write_file(parfilp);
dput(dentry);
return error;
}
STATIC int
xfs_attrlist_by_handle(
struct file *parfilp,
void __user *arg)
{
int error = -ENOMEM;
attrlist_cursor_kern_t *cursor;
xfs_fsop_attrlist_handlereq_t al_hreq;
struct dentry *dentry;
char *kbuf;
if (!capable(CAP_SYS_ADMIN))
return -XFS_ERROR(EPERM);
if (copy_from_user(&al_hreq, arg, sizeof(xfs_fsop_attrlist_handlereq_t)))
return -XFS_ERROR(EFAULT);
if (al_hreq.buflen > XATTR_LIST_MAX)
return -XFS_ERROR(EINVAL);
/*
* Reject flags, only allow namespaces.
*/
if (al_hreq.flags & ~(ATTR_ROOT | ATTR_SECURE))
return -XFS_ERROR(EINVAL);
dentry = xfs_handlereq_to_dentry(parfilp, &al_hreq.hreq);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
kbuf = kzalloc(al_hreq.buflen, GFP_KERNEL);
if (!kbuf)
goto out_dput;
cursor = (attrlist_cursor_kern_t *)&al_hreq.pos;
error = -xfs_attr_list(XFS_I(dentry->d_inode), kbuf, al_hreq.buflen,
al_hreq.flags, cursor);
if (error)
goto out_kfree;
if (copy_to_user(al_hreq.buffer, kbuf, al_hreq.buflen))
error = -EFAULT;
out_kfree:
kfree(kbuf);
out_dput:
dput(dentry);
return error;
}
int
xfs_attrmulti_attr_get(
struct inode *inode,
unsigned char *name,
unsigned char __user *ubuf,
__uint32_t *len,
__uint32_t flags)
{
unsigned char *kbuf;
int error = EFAULT;
if (*len > XATTR_SIZE_MAX)
return EINVAL;
kbuf = kmem_zalloc(*len, KM_SLEEP | KM_MAYFAIL);
if (!kbuf) {
kbuf = kmem_zalloc_large(*len);
if (!kbuf)
return ENOMEM;
}
error = xfs_attr_get(XFS_I(inode), name, kbuf, (int *)len, flags);
if (error)
goto out_kfree;
if (copy_to_user(ubuf, kbuf, *len))
error = EFAULT;
out_kfree:
if (is_vmalloc_addr(kbuf))
kmem_free_large(kbuf);
else
kmem_free(kbuf);
return error;
}
int
xfs_attrmulti_attr_set(
struct inode *inode,
unsigned char *name,
const unsigned char __user *ubuf,
__uint32_t len,
__uint32_t flags)
{
unsigned char *kbuf;
int error = EFAULT;
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
return EPERM;
if (len > XATTR_SIZE_MAX)
return EINVAL;
kbuf = memdup_user(ubuf, len);
if (IS_ERR(kbuf))
return PTR_ERR(kbuf);
error = xfs_attr_set(XFS_I(inode), name, kbuf, len, flags);
return error;
}
int
xfs_attrmulti_attr_remove(
struct inode *inode,
unsigned char *name,
__uint32_t flags)
{
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
return EPERM;
return xfs_attr_remove(XFS_I(inode), name, flags);
}
STATIC int
xfs_attrmulti_by_handle(
struct file *parfilp,
void __user *arg)
{
int error;
xfs_attr_multiop_t *ops;
xfs_fsop_attrmulti_handlereq_t am_hreq;
struct dentry *dentry;
unsigned int i, size;
unsigned char *attr_name;
if (!capable(CAP_SYS_ADMIN))
return -XFS_ERROR(EPERM);
if (copy_from_user(&am_hreq, arg, sizeof(xfs_fsop_attrmulti_handlereq_t)))
return -XFS_ERROR(EFAULT);
/* overflow check */
if (am_hreq.opcount >= INT_MAX / sizeof(xfs_attr_multiop_t))
return -E2BIG;
dentry = xfs_handlereq_to_dentry(parfilp, &am_hreq.hreq);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
error = E2BIG;
size = am_hreq.opcount * sizeof(xfs_attr_multiop_t);
if (!size || size > 16 * PAGE_SIZE)
goto out_dput;
ops = memdup_user(am_hreq.ops, size);
if (IS_ERR(ops)) {
error = PTR_ERR(ops);
goto out_dput;
}
attr_name = kmalloc(MAXNAMELEN, GFP_KERNEL);
if (!attr_name)
goto out_kfree_ops;
error = 0;
for (i = 0; i < am_hreq.opcount; i++) {
ops[i].am_error = strncpy_from_user((char *)attr_name,
ops[i].am_attrname, MAXNAMELEN);
if (ops[i].am_error == 0 || ops[i].am_error == MAXNAMELEN)
error = -ERANGE;
if (ops[i].am_error < 0)
break;
switch (ops[i].am_opcode) {
case ATTR_OP_GET:
ops[i].am_error = xfs_attrmulti_attr_get(
dentry->d_inode, attr_name,
ops[i].am_attrvalue, &ops[i].am_length,
ops[i].am_flags);
break;
case ATTR_OP_SET:
ops[i].am_error = mnt_want_write_file(parfilp);
if (ops[i].am_error)
break;
ops[i].am_error = xfs_attrmulti_attr_set(
dentry->d_inode, attr_name,
ops[i].am_attrvalue, ops[i].am_length,
ops[i].am_flags);
mnt_drop_write_file(parfilp);
break;
case ATTR_OP_REMOVE:
ops[i].am_error = mnt_want_write_file(parfilp);
if (ops[i].am_error)
break;
ops[i].am_error = xfs_attrmulti_attr_remove(
dentry->d_inode, attr_name,
ops[i].am_flags);
mnt_drop_write_file(parfilp);
break;
default:
ops[i].am_error = EINVAL;
}
}
if (copy_to_user(am_hreq.ops, ops, size))
error = XFS_ERROR(EFAULT);
kfree(attr_name);
out_kfree_ops:
kfree(ops);
out_dput:
dput(dentry);
return -error;
}
int
xfs_ioc_space(
struct xfs_inode *ip,
struct inode *inode,
struct file *filp,
int ioflags,
unsigned int cmd,
xfs_flock64_t *bf)
{
int attr_flags = 0;
int error;
/*
* Only allow the sys admin to reserve space unless
* unwritten extents are enabled.
*/
if (!xfs_sb_version_hasextflgbit(&ip->i_mount->m_sb) &&
!capable(CAP_SYS_ADMIN))
return -XFS_ERROR(EPERM);
if (inode->i_flags & (S_IMMUTABLE|S_APPEND))
return -XFS_ERROR(EPERM);
if (!(filp->f_mode & FMODE_WRITE))
return -XFS_ERROR(EBADF);
if (!S_ISREG(inode->i_mode))
return -XFS_ERROR(EINVAL);
if (filp->f_flags & (O_NDELAY|O_NONBLOCK))
attr_flags |= XFS_ATTR_NONBLOCK;
if (filp->f_flags & O_DSYNC)
attr_flags |= XFS_ATTR_SYNC;
if (ioflags & IO_INVIS)
attr_flags |= XFS_ATTR_DMI;
error = mnt_want_write_file(filp);
if (error)
return error;
error = xfs_change_file_space(ip, cmd, bf, filp->f_pos, attr_flags);
mnt_drop_write_file(filp);
return -error;
}
STATIC int
xfs_ioc_bulkstat(
xfs_mount_t *mp,
unsigned int cmd,
void __user *arg)
{
xfs_fsop_bulkreq_t bulkreq;
int count; /* # of records returned */
xfs_ino_t inlast; /* last inode number */
int done;
int error;
/* done = 1 if there are more stats to get and if bulkstat */
/* should be called again (unused here, but used in dmapi) */
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (XFS_FORCED_SHUTDOWN(mp))
return -XFS_ERROR(EIO);
if (copy_from_user(&bulkreq, arg, sizeof(xfs_fsop_bulkreq_t)))
return -XFS_ERROR(EFAULT);
if (copy_from_user(&inlast, bulkreq.lastip, sizeof(__s64)))
return -XFS_ERROR(EFAULT);
if ((count = bulkreq.icount) <= 0)
return -XFS_ERROR(EINVAL);
if (bulkreq.ubuffer == NULL)
return -XFS_ERROR(EINVAL);
if (cmd == XFS_IOC_FSINUMBERS)
error = xfs_inumbers(mp, &inlast, &count,
bulkreq.ubuffer, xfs_inumbers_fmt);
else if (cmd == XFS_IOC_FSBULKSTAT_SINGLE)
error = xfs_bulkstat_single(mp, &inlast,
bulkreq.ubuffer, &done);
else /* XFS_IOC_FSBULKSTAT */
error = xfs_bulkstat(mp, &inlast, &count, xfs_bulkstat_one,
sizeof(xfs_bstat_t), bulkreq.ubuffer,
&done);
if (error)
return -error;
if (bulkreq.ocount != NULL) {
if (copy_to_user(bulkreq.lastip, &inlast,
sizeof(xfs_ino_t)))
return -XFS_ERROR(EFAULT);
if (copy_to_user(bulkreq.ocount, &count, sizeof(count)))
return -XFS_ERROR(EFAULT);
}
return 0;
}
STATIC int
xfs_ioc_fsgeometry_v1(
xfs_mount_t *mp,
void __user *arg)
{
xfs_fsop_geom_t fsgeo;
int error;
error = xfs_fs_geometry(mp, &fsgeo, 3);
if (error)
return -error;
/*
* Caller should have passed an argument of type
* xfs_fsop_geom_v1_t. This is a proper subset of the
* xfs_fsop_geom_t that xfs_fs_geometry() fills in.
*/
if (copy_to_user(arg, &fsgeo, sizeof(xfs_fsop_geom_v1_t)))
return -XFS_ERROR(EFAULT);
return 0;
}
STATIC int
xfs_ioc_fsgeometry(
xfs_mount_t *mp,
void __user *arg)
{
xfs_fsop_geom_t fsgeo;
int error;
error = xfs_fs_geometry(mp, &fsgeo, 4);
if (error)
return -error;
if (copy_to_user(arg, &fsgeo, sizeof(fsgeo)))
return -XFS_ERROR(EFAULT);
return 0;
}
/*
* Linux extended inode flags interface.
*/
STATIC unsigned int
xfs_merge_ioc_xflags(
unsigned int flags,
unsigned int start)
{
unsigned int xflags = start;
if (flags & FS_IMMUTABLE_FL)
xflags |= XFS_XFLAG_IMMUTABLE;
else
xflags &= ~XFS_XFLAG_IMMUTABLE;
if (flags & FS_APPEND_FL)
xflags |= XFS_XFLAG_APPEND;
else
xflags &= ~XFS_XFLAG_APPEND;
if (flags & FS_SYNC_FL)
xflags |= XFS_XFLAG_SYNC;
else
xflags &= ~XFS_XFLAG_SYNC;
if (flags & FS_NOATIME_FL)
xflags |= XFS_XFLAG_NOATIME;
else
xflags &= ~XFS_XFLAG_NOATIME;
if (flags & FS_NODUMP_FL)
xflags |= XFS_XFLAG_NODUMP;
else
xflags &= ~XFS_XFLAG_NODUMP;
return xflags;
}
STATIC unsigned int
xfs_di2lxflags(
__uint16_t di_flags)
{
unsigned int flags = 0;
if (di_flags & XFS_DIFLAG_IMMUTABLE)
flags |= FS_IMMUTABLE_FL;
if (di_flags & XFS_DIFLAG_APPEND)
flags |= FS_APPEND_FL;
if (di_flags & XFS_DIFLAG_SYNC)
flags |= FS_SYNC_FL;
if (di_flags & XFS_DIFLAG_NOATIME)
flags |= FS_NOATIME_FL;
if (di_flags & XFS_DIFLAG_NODUMP)
flags |= FS_NODUMP_FL;
return flags;
}
STATIC int
xfs_ioc_fsgetxattr(
xfs_inode_t *ip,
int attr,
void __user *arg)
{
struct fsxattr fa;
memset(&fa, 0, sizeof(struct fsxattr));
xfs_ilock(ip, XFS_ILOCK_SHARED);
fa.fsx_xflags = xfs_ip2xflags(ip);
fa.fsx_extsize = ip->i_d.di_extsize << ip->i_mount->m_sb.sb_blocklog;
fa.fsx_projid = xfs_get_projid(ip);
if (attr) {
if (ip->i_afp) {
if (ip->i_afp->if_flags & XFS_IFEXTENTS)
fa.fsx_nextents = ip->i_afp->if_bytes /
sizeof(xfs_bmbt_rec_t);
else
fa.fsx_nextents = ip->i_d.di_anextents;
} else
fa.fsx_nextents = 0;
} else {
if (ip->i_df.if_flags & XFS_IFEXTENTS)
fa.fsx_nextents = ip->i_df.if_bytes /
sizeof(xfs_bmbt_rec_t);
else
fa.fsx_nextents = ip->i_d.di_nextents;
}
xfs_iunlock(ip, XFS_ILOCK_SHARED);
if (copy_to_user(arg, &fa, sizeof(fa)))
return -EFAULT;
return 0;
}
STATIC void
xfs_set_diflags(
struct xfs_inode *ip,
unsigned int xflags)
{
unsigned int di_flags;
/* can't set PREALLOC this way, just preserve it */
di_flags = (ip->i_d.di_flags & XFS_DIFLAG_PREALLOC);
if (xflags & XFS_XFLAG_IMMUTABLE)
di_flags |= XFS_DIFLAG_IMMUTABLE;
if (xflags & XFS_XFLAG_APPEND)
di_flags |= XFS_DIFLAG_APPEND;
if (xflags & XFS_XFLAG_SYNC)
di_flags |= XFS_DIFLAG_SYNC;
if (xflags & XFS_XFLAG_NOATIME)
di_flags |= XFS_DIFLAG_NOATIME;
if (xflags & XFS_XFLAG_NODUMP)
di_flags |= XFS_DIFLAG_NODUMP;
if (xflags & XFS_XFLAG_PROJINHERIT)
di_flags |= XFS_DIFLAG_PROJINHERIT;
if (xflags & XFS_XFLAG_NODEFRAG)
di_flags |= XFS_DIFLAG_NODEFRAG;
if (xflags & XFS_XFLAG_FILESTREAM)
di_flags |= XFS_DIFLAG_FILESTREAM;
if (S_ISDIR(ip->i_d.di_mode)) {
if (xflags & XFS_XFLAG_RTINHERIT)
di_flags |= XFS_DIFLAG_RTINHERIT;
if (xflags & XFS_XFLAG_NOSYMLINKS)
di_flags |= XFS_DIFLAG_NOSYMLINKS;
if (xflags & XFS_XFLAG_EXTSZINHERIT)
di_flags |= XFS_DIFLAG_EXTSZINHERIT;
} else if (S_ISREG(ip->i_d.di_mode)) {
if (xflags & XFS_XFLAG_REALTIME)
di_flags |= XFS_DIFLAG_REALTIME;
if (xflags & XFS_XFLAG_EXTSIZE)
di_flags |= XFS_DIFLAG_EXTSIZE;
}
ip->i_d.di_flags = di_flags;
}
STATIC void
xfs_diflags_to_linux(
struct xfs_inode *ip)
{
struct inode *inode = VFS_I(ip);
unsigned int xflags = xfs_ip2xflags(ip);
if (xflags & XFS_XFLAG_IMMUTABLE)
inode->i_flags |= S_IMMUTABLE;
else
inode->i_flags &= ~S_IMMUTABLE;
if (xflags & XFS_XFLAG_APPEND)
inode->i_flags |= S_APPEND;
else
inode->i_flags &= ~S_APPEND;
if (xflags & XFS_XFLAG_SYNC)
inode->i_flags |= S_SYNC;
else
inode->i_flags &= ~S_SYNC;
if (xflags & XFS_XFLAG_NOATIME)
inode->i_flags |= S_NOATIME;
else
inode->i_flags &= ~S_NOATIME;
}
#define FSX_PROJID 1
#define FSX_EXTSIZE 2
#define FSX_XFLAGS 4
#define FSX_NONBLOCK 8
STATIC int
xfs_ioctl_setattr(
xfs_inode_t *ip,
struct fsxattr *fa,
int mask)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_trans *tp;
unsigned int lock_flags = 0;
struct xfs_dquot *udqp = NULL;
struct xfs_dquot *gdqp = NULL;
struct xfs_dquot *olddquot = NULL;
int code;
trace_xfs_ioctl_setattr(ip);
if (mp->m_flags & XFS_MOUNT_RDONLY)
return XFS_ERROR(EROFS);
if (XFS_FORCED_SHUTDOWN(mp))
return XFS_ERROR(EIO);
/*
* Disallow 32bit project ids when projid32bit feature is not enabled.
*/
if ((mask & FSX_PROJID) && (fa->fsx_projid > (__uint16_t)-1) &&
!xfs_sb_version_hasprojid32bit(&ip->i_mount->m_sb))
return XFS_ERROR(EINVAL);
/*
* If disk quotas is on, we make sure that the dquots do exist on disk,
* before we start any other transactions. Trying to do this later
* is messy. We don't care to take a readlock to look at the ids
* in inode here, because we can't hold it across the trans_reserve.
* If the IDs do change before we take the ilock, we're covered
* because the i_*dquot fields will get updated anyway.
*/
if (XFS_IS_QUOTA_ON(mp) && (mask & FSX_PROJID)) {
code = xfs_qm_vop_dqalloc(ip, ip->i_d.di_uid,
ip->i_d.di_gid, fa->fsx_projid,
XFS_QMOPT_PQUOTA, &udqp, &gdqp);
if (code)
return code;
}
/*
* For the other attributes, we acquire the inode lock and
* first do an error checking pass.
*/
tp = xfs_trans_alloc(mp, XFS_TRANS_SETATTR_NOT_SIZE);
code = xfs_trans_reserve(tp, 0, XFS_ICHANGE_LOG_RES(mp), 0, 0, 0);
if (code)
goto error_return;
lock_flags = XFS_ILOCK_EXCL;
xfs_ilock(ip, lock_flags);
/*
* CAP_FOWNER overrides the following restrictions:
*
* The user ID of the calling process must be equal
* to the file owner ID, except in cases where the
* CAP_FSETID capability is applicable.
*/
if (current_fsuid() != ip->i_d.di_uid && !capable(CAP_FOWNER)) {
code = XFS_ERROR(EPERM);
goto error_return;
}
/*
* Do a quota reservation only if projid is actually going to change.
*/
if (mask & FSX_PROJID) {
if (XFS_IS_QUOTA_RUNNING(mp) &&
XFS_IS_PQUOTA_ON(mp) &&
xfs_get_projid(ip) != fa->fsx_projid) {
ASSERT(tp);
code = xfs_qm_vop_chown_reserve(tp, ip, udqp, gdqp,
capable(CAP_FOWNER) ?
XFS_QMOPT_FORCE_RES : 0);
if (code) /* out of quota */
goto error_return;
}
}
if (mask & FSX_EXTSIZE) {
/*
* Can't change extent size if any extents are allocated.
*/
if (ip->i_d.di_nextents &&
((ip->i_d.di_extsize << mp->m_sb.sb_blocklog) !=
fa->fsx_extsize)) {
code = XFS_ERROR(EINVAL); /* EFBIG? */
goto error_return;
}
/*
* Extent size must be a multiple of the appropriate block
* size, if set at all. It must also be smaller than the
* maximum extent size supported by the filesystem.
*
* Also, for non-realtime files, limit the extent size hint to
* half the size of the AGs in the filesystem so alignment
* doesn't result in extents larger than an AG.
*/
if (fa->fsx_extsize != 0) {
xfs_extlen_t size;
xfs_fsblock_t extsize_fsb;
extsize_fsb = XFS_B_TO_FSB(mp, fa->fsx_extsize);
if (extsize_fsb > MAXEXTLEN) {
code = XFS_ERROR(EINVAL);
goto error_return;
}
if (XFS_IS_REALTIME_INODE(ip) ||
((mask & FSX_XFLAGS) &&
(fa->fsx_xflags & XFS_XFLAG_REALTIME))) {
size = mp->m_sb.sb_rextsize <<
mp->m_sb.sb_blocklog;
} else {
size = mp->m_sb.sb_blocksize;
if (extsize_fsb > mp->m_sb.sb_agblocks / 2) {
code = XFS_ERROR(EINVAL);
goto error_return;
}
}
if (fa->fsx_extsize % size) {
code = XFS_ERROR(EINVAL);
goto error_return;
}
}
}
if (mask & FSX_XFLAGS) {
/*
* Can't change realtime flag if any extents are allocated.
*/
if ((ip->i_d.di_nextents || ip->i_delayed_blks) &&
(XFS_IS_REALTIME_INODE(ip)) !=
(fa->fsx_xflags & XFS_XFLAG_REALTIME)) {
code = XFS_ERROR(EINVAL); /* EFBIG? */
goto error_return;
}
/*
* If realtime flag is set then must have realtime data.
*/
if ((fa->fsx_xflags & XFS_XFLAG_REALTIME)) {
if ((mp->m_sb.sb_rblocks == 0) ||
(mp->m_sb.sb_rextsize == 0) ||
(ip->i_d.di_extsize % mp->m_sb.sb_rextsize)) {
code = XFS_ERROR(EINVAL);
goto error_return;
}
}
/*
* Can't modify an immutable/append-only file unless
* we have appropriate permission.
*/
if ((ip->i_d.di_flags &
(XFS_DIFLAG_IMMUTABLE|XFS_DIFLAG_APPEND) ||
(fa->fsx_xflags &
(XFS_XFLAG_IMMUTABLE | XFS_XFLAG_APPEND))) &&
!capable(CAP_LINUX_IMMUTABLE)) {
code = XFS_ERROR(EPERM);
goto error_return;
}
}
xfs_trans_ijoin(tp, ip, 0);
/*
* Change file ownership. Must be the owner or privileged.
*/
if (mask & FSX_PROJID) {
/*
* CAP_FSETID overrides the following restrictions:
*
* The set-user-ID and set-group-ID bits of a file will be
* cleared upon successful return from chown()
*/
if ((ip->i_d.di_mode & (S_ISUID|S_ISGID)) &&
!capable(CAP_FSETID))
ip->i_d.di_mode &= ~(S_ISUID|S_ISGID);
/*
* Change the ownerships and register quota modifications
* in the transaction.
*/
if (xfs_get_projid(ip) != fa->fsx_projid) {
if (XFS_IS_QUOTA_RUNNING(mp) && XFS_IS_PQUOTA_ON(mp)) {
olddquot = xfs_qm_vop_chown(tp, ip,
&ip->i_gdquot, gdqp);
}
xfs_set_projid(ip, fa->fsx_projid);
/*
* We may have to rev the inode as well as
* the superblock version number since projids didn't
* exist before DINODE_VERSION_2 and SB_VERSION_NLINK.
*/
if (ip->i_d.di_version == 1)
xfs_bump_ino_vers2(tp, ip);
}
}
if (mask & FSX_EXTSIZE)
ip->i_d.di_extsize = fa->fsx_extsize >> mp->m_sb.sb_blocklog;
if (mask & FSX_XFLAGS) {
xfs_set_diflags(ip, fa->fsx_xflags);
xfs_diflags_to_linux(ip);
}
xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_CHG);
xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
XFS_STATS_INC(xs_ig_attrchg);
/*
* If this is a synchronous mount, make sure that the
* transaction goes to disk before returning to the user.
* This is slightly sub-optimal in that truncates require
* two sync transactions instead of one for wsync filesystems.
* One for the truncate and one for the timestamps since we
* don't want to change the timestamps unless we're sure the
* truncate worked. Truncates are less than 1% of the laddis
* mix so this probably isn't worth the trouble to optimize.
*/
if (mp->m_flags & XFS_MOUNT_WSYNC)
xfs_trans_set_sync(tp);
code = xfs_trans_commit(tp, 0);
xfs_iunlock(ip, lock_flags);
/*
* Release any dquot(s) the inode had kept before chown.
*/
xfs_qm_dqrele(olddquot);
xfs_qm_dqrele(udqp);
xfs_qm_dqrele(gdqp);
return code;
error_return:
xfs_qm_dqrele(udqp);
xfs_qm_dqrele(gdqp);
xfs_trans_cancel(tp, 0);
if (lock_flags)
xfs_iunlock(ip, lock_flags);
return code;
}
STATIC int
xfs_ioc_fssetxattr(
xfs_inode_t *ip,
struct file *filp,
void __user *arg)
{
struct fsxattr fa;
unsigned int mask;
int error;
if (copy_from_user(&fa, arg, sizeof(fa)))
return -EFAULT;
mask = FSX_XFLAGS | FSX_EXTSIZE | FSX_PROJID;
if (filp->f_flags & (O_NDELAY|O_NONBLOCK))
mask |= FSX_NONBLOCK;
error = mnt_want_write_file(filp);
if (error)
return error;
error = xfs_ioctl_setattr(ip, &fa, mask);
mnt_drop_write_file(filp);
return -error;
}
STATIC int
xfs_ioc_getxflags(
xfs_inode_t *ip,
void __user *arg)
{
unsigned int flags;
flags = xfs_di2lxflags(ip->i_d.di_flags);
if (copy_to_user(arg, &flags, sizeof(flags)))
return -EFAULT;
return 0;
}
STATIC int
xfs_ioc_setxflags(
xfs_inode_t *ip,
struct file *filp,
void __user *arg)
{
struct fsxattr fa;
unsigned int flags;
unsigned int mask;
int error;
if (copy_from_user(&flags, arg, sizeof(flags)))
return -EFAULT;
if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
FS_NOATIME_FL | FS_NODUMP_FL | \
FS_SYNC_FL))
return -EOPNOTSUPP;
mask = FSX_XFLAGS;
if (filp->f_flags & (O_NDELAY|O_NONBLOCK))
mask |= FSX_NONBLOCK;
fa.fsx_xflags = xfs_merge_ioc_xflags(flags, xfs_ip2xflags(ip));
error = mnt_want_write_file(filp);
if (error)
return error;
error = xfs_ioctl_setattr(ip, &fa, mask);
mnt_drop_write_file(filp);
return -error;
}
STATIC int
xfs_getbmap_format(void **ap, struct getbmapx *bmv, int *full)
{
struct getbmap __user *base = *ap;
/* copy only getbmap portion (not getbmapx) */
if (copy_to_user(base, bmv, sizeof(struct getbmap)))
return XFS_ERROR(EFAULT);
*ap += sizeof(struct getbmap);
return 0;
}
STATIC int
xfs_ioc_getbmap(
struct xfs_inode *ip,
int ioflags,
unsigned int cmd,
void __user *arg)
{
struct getbmapx bmx;
int error;
if (copy_from_user(&bmx, arg, sizeof(struct getbmapx)))
return -XFS_ERROR(EFAULT);
if (bmx.bmv_count < 2)
return -XFS_ERROR(EINVAL);
bmx.bmv_iflags = (cmd == XFS_IOC_GETBMAPA ? BMV_IF_ATTRFORK : 0);
if (ioflags & IO_INVIS)
bmx.bmv_iflags |= BMV_IF_NO_DMAPI_READ;
error = xfs_getbmap(ip, &bmx, xfs_getbmap_format,
(struct getbmap *)arg+1);
if (error)
return -error;
/* copy back header - only size of getbmap */
if (copy_to_user(arg, &bmx, sizeof(struct getbmap)))
return -XFS_ERROR(EFAULT);
return 0;
}
STATIC int
xfs_getbmapx_format(void **ap, struct getbmapx *bmv, int *full)
{
struct getbmapx __user *base = *ap;
if (copy_to_user(base, bmv, sizeof(struct getbmapx)))
return XFS_ERROR(EFAULT);
*ap += sizeof(struct getbmapx);
return 0;
}
STATIC int
xfs_ioc_getbmapx(
struct xfs_inode *ip,
void __user *arg)
{
struct getbmapx bmx;
int error;
if (copy_from_user(&bmx, arg, sizeof(bmx)))
return -XFS_ERROR(EFAULT);
if (bmx.bmv_count < 2)
return -XFS_ERROR(EINVAL);
if (bmx.bmv_iflags & (~BMV_IF_VALID))
return -XFS_ERROR(EINVAL);
error = xfs_getbmap(ip, &bmx, xfs_getbmapx_format,
(struct getbmapx *)arg+1);
if (error)
return -error;
/* copy back header */
if (copy_to_user(arg, &bmx, sizeof(struct getbmapx)))
return -XFS_ERROR(EFAULT);
return 0;
}
/*
* Note: some of the ioctl's return positive numbers as a
* byte count indicating success, such as readlink_by_handle.
* So we don't "sign flip" like most other routines. This means
* true errors need to be returned as a negative value.
*/
long
xfs_file_ioctl(
struct file *filp,
unsigned int cmd,
unsigned long p)
{
struct inode *inode = file_inode(filp);
struct xfs_inode *ip = XFS_I(inode);
struct xfs_mount *mp = ip->i_mount;
void __user *arg = (void __user *)p;
int ioflags = 0;
int error;
if (filp->f_mode & FMODE_NOCMTIME)
ioflags |= IO_INVIS;
trace_xfs_file_ioctl(ip);
switch (cmd) {
case FITRIM:
return xfs_ioc_trim(mp, arg);
case XFS_IOC_ALLOCSP:
case XFS_IOC_FREESP:
case XFS_IOC_RESVSP:
case XFS_IOC_UNRESVSP:
case XFS_IOC_ALLOCSP64:
case XFS_IOC_FREESP64:
case XFS_IOC_RESVSP64:
case XFS_IOC_UNRESVSP64:
case XFS_IOC_ZERO_RANGE: {
xfs_flock64_t bf;
if (copy_from_user(&bf, arg, sizeof(bf)))
return -XFS_ERROR(EFAULT);
return xfs_ioc_space(ip, inode, filp, ioflags, cmd, &bf);
}
case XFS_IOC_DIOINFO: {
struct dioattr da;
xfs_buftarg_t *target =
XFS_IS_REALTIME_INODE(ip) ?
mp->m_rtdev_targp : mp->m_ddev_targp;
da.d_mem = da.d_miniosz = 1 << target->bt_sshift;
da.d_maxiosz = INT_MAX & ~(da.d_miniosz - 1);
if (copy_to_user(arg, &da, sizeof(da)))
return -XFS_ERROR(EFAULT);
return 0;
}
case XFS_IOC_FSBULKSTAT_SINGLE:
case XFS_IOC_FSBULKSTAT:
case XFS_IOC_FSINUMBERS:
return xfs_ioc_bulkstat(mp, cmd, arg);
case XFS_IOC_FSGEOMETRY_V1:
return xfs_ioc_fsgeometry_v1(mp, arg);
case XFS_IOC_FSGEOMETRY:
return xfs_ioc_fsgeometry(mp, arg);
case XFS_IOC_GETVERSION:
return put_user(inode->i_generation, (int __user *)arg);
case XFS_IOC_FSGETXATTR:
return xfs_ioc_fsgetxattr(ip, 0, arg);
case XFS_IOC_FSGETXATTRA:
return xfs_ioc_fsgetxattr(ip, 1, arg);
case XFS_IOC_FSSETXATTR:
return xfs_ioc_fssetxattr(ip, filp, arg);
case XFS_IOC_GETXFLAGS:
return xfs_ioc_getxflags(ip, arg);
case XFS_IOC_SETXFLAGS:
return xfs_ioc_setxflags(ip, filp, arg);
case XFS_IOC_FSSETDM: {
struct fsdmidata dmi;
if (copy_from_user(&dmi, arg, sizeof(dmi)))
return -XFS_ERROR(EFAULT);
error = mnt_want_write_file(filp);
if (error)
return error;
error = xfs_set_dmattrs(ip, dmi.fsd_dmevmask,
dmi.fsd_dmstate);
mnt_drop_write_file(filp);
return -error;
}
case XFS_IOC_GETBMAP:
case XFS_IOC_GETBMAPA:
return xfs_ioc_getbmap(ip, ioflags, cmd, arg);
case XFS_IOC_GETBMAPX:
return xfs_ioc_getbmapx(ip, arg);
case XFS_IOC_FD_TO_HANDLE:
case XFS_IOC_PATH_TO_HANDLE:
case XFS_IOC_PATH_TO_FSHANDLE: {
xfs_fsop_handlereq_t hreq;
if (copy_from_user(&hreq, arg, sizeof(hreq)))
return -XFS_ERROR(EFAULT);
return xfs_find_handle(cmd, &hreq);
}
case XFS_IOC_OPEN_BY_HANDLE: {
xfs_fsop_handlereq_t hreq;
if (copy_from_user(&hreq, arg, sizeof(xfs_fsop_handlereq_t)))
return -XFS_ERROR(EFAULT);
return xfs_open_by_handle(filp, &hreq);
}
case XFS_IOC_FSSETDM_BY_HANDLE:
return xfs_fssetdm_by_handle(filp, arg);
case XFS_IOC_READLINK_BY_HANDLE: {
xfs_fsop_handlereq_t hreq;
if (copy_from_user(&hreq, arg, sizeof(xfs_fsop_handlereq_t)))
return -XFS_ERROR(EFAULT);
return xfs_readlink_by_handle(filp, &hreq);
}
case XFS_IOC_ATTRLIST_BY_HANDLE:
return xfs_attrlist_by_handle(filp, arg);
case XFS_IOC_ATTRMULTI_BY_HANDLE:
return xfs_attrmulti_by_handle(filp, arg);
case XFS_IOC_SWAPEXT: {
struct xfs_swapext sxp;
if (copy_from_user(&sxp, arg, sizeof(xfs_swapext_t)))
return -XFS_ERROR(EFAULT);
error = mnt_want_write_file(filp);
if (error)
return error;
error = xfs_swapext(&sxp);
mnt_drop_write_file(filp);
return -error;
}
case XFS_IOC_FSCOUNTS: {
xfs_fsop_counts_t out;
error = xfs_fs_counts(mp, &out);
if (error)
return -error;
if (copy_to_user(arg, &out, sizeof(out)))
return -XFS_ERROR(EFAULT);
return 0;
}
case XFS_IOC_SET_RESBLKS: {
xfs_fsop_resblks_t inout;
__uint64_t in;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (mp->m_flags & XFS_MOUNT_RDONLY)
return -XFS_ERROR(EROFS);
if (copy_from_user(&inout, arg, sizeof(inout)))
return -XFS_ERROR(EFAULT);
error = mnt_want_write_file(filp);
if (error)
return error;
/* input parameter is passed in resblks field of structure */
in = inout.resblks;
error = xfs_reserve_blocks(mp, &in, &inout);
mnt_drop_write_file(filp);
if (error)
return -error;
if (copy_to_user(arg, &inout, sizeof(inout)))
return -XFS_ERROR(EFAULT);
return 0;
}
case XFS_IOC_GET_RESBLKS: {
xfs_fsop_resblks_t out;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
error = xfs_reserve_blocks(mp, NULL, &out);
if (error)
return -error;
if (copy_to_user(arg, &out, sizeof(out)))
return -XFS_ERROR(EFAULT);
return 0;
}
case XFS_IOC_FSGROWFSDATA: {
xfs_growfs_data_t in;
if (copy_from_user(&in, arg, sizeof(in)))
return -XFS_ERROR(EFAULT);
error = mnt_want_write_file(filp);
if (error)
return error;
error = xfs_growfs_data(mp, &in);
mnt_drop_write_file(filp);
return -error;
}
case XFS_IOC_FSGROWFSLOG: {
xfs_growfs_log_t in;
if (copy_from_user(&in, arg, sizeof(in)))
return -XFS_ERROR(EFAULT);
error = mnt_want_write_file(filp);
if (error)
return error;
error = xfs_growfs_log(mp, &in);
mnt_drop_write_file(filp);
return -error;
}
case XFS_IOC_FSGROWFSRT: {
xfs_growfs_rt_t in;
if (copy_from_user(&in, arg, sizeof(in)))
return -XFS_ERROR(EFAULT);
error = mnt_want_write_file(filp);
if (error)
return error;
error = xfs_growfs_rt(mp, &in);
mnt_drop_write_file(filp);
return -error;
}
case XFS_IOC_GOINGDOWN: {
__uint32_t in;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (get_user(in, (__uint32_t __user *)arg))
return -XFS_ERROR(EFAULT);
error = xfs_fs_goingdown(mp, in);
return -error;
}
case XFS_IOC_ERROR_INJECTION: {
xfs_error_injection_t in;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (copy_from_user(&in, arg, sizeof(in)))
return -XFS_ERROR(EFAULT);
error = xfs_errortag_add(in.errtag, mp);
return -error;
}
case XFS_IOC_ERROR_CLEARALL:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
error = xfs_errortag_clearall(mp, 1);
return -error;
case XFS_IOC_FREE_EOFBLOCKS: {
struct xfs_eofblocks eofb;
if (copy_from_user(&eofb, arg, sizeof(eofb)))
return -XFS_ERROR(EFAULT);
if (eofb.eof_version != XFS_EOFBLOCKS_VERSION)
return -XFS_ERROR(EINVAL);
if (eofb.eof_flags & ~XFS_EOF_FLAGS_VALID)
return -XFS_ERROR(EINVAL);
if (memchr_inv(&eofb.pad32, 0, sizeof(eofb.pad32)) ||
memchr_inv(eofb.pad64, 0, sizeof(eofb.pad64)))
return -XFS_ERROR(EINVAL);
error = xfs_icache_free_eofblocks(mp, &eofb);
return -error;
}
default:
return -ENOTTY;
}
}
Reference in New Issue View Git Blame Copy Permalink