linux/fs/ceph/xattr.c
Luis Henriques 12fe3dda7e ceph: fix buffer free while holding i_ceph_lock in __ceph_build_xattrs_blob()
Calling ceph_buffer_put() in __ceph_build_xattrs_blob() may result in
freeing the i_xattrs.blob buffer while holding the i_ceph_lock.  This can
be fixed by having this function returning the old blob buffer and have
the callers of this function freeing it when the lock is released.

The following backtrace was triggered by fstests generic/117.

  BUG: sleeping function called from invalid context at mm/vmalloc.c:2283
  in_atomic(): 1, irqs_disabled(): 0, pid: 649, name: fsstress
  4 locks held by fsstress/649:
   #0: 00000000a7478e7e (&type->s_umount_key#19){++++}, at: iterate_supers+0x77/0xf0
   #1: 00000000f8de1423 (&(&ci->i_ceph_lock)->rlock){+.+.}, at: ceph_check_caps+0x7b/0xc60
   #2: 00000000562f2b27 (&s->s_mutex){+.+.}, at: ceph_check_caps+0x3bd/0xc60
   #3: 00000000f83ce16a (&mdsc->snap_rwsem){++++}, at: ceph_check_caps+0x3ed/0xc60
  CPU: 1 PID: 649 Comm: fsstress Not tainted 5.2.0+ #439
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014
  Call Trace:
   dump_stack+0x67/0x90
   ___might_sleep.cold+0x9f/0xb1
   vfree+0x4b/0x60
   ceph_buffer_release+0x1b/0x60
   __ceph_build_xattrs_blob+0x12b/0x170
   __send_cap+0x302/0x540
   ? __lock_acquire+0x23c/0x1e40
   ? __mark_caps_flushing+0x15c/0x280
   ? _raw_spin_unlock+0x24/0x30
   ceph_check_caps+0x5f0/0xc60
   ceph_flush_dirty_caps+0x7c/0x150
   ? __ia32_sys_fdatasync+0x20/0x20
   ceph_sync_fs+0x5a/0x130
   iterate_supers+0x8f/0xf0
   ksys_sync+0x4f/0xb0
   __ia32_sys_sync+0xa/0x10
   do_syscall_64+0x50/0x1c0
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x7fc6409ab617

Signed-off-by: Luis Henriques <lhenriques@suse.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2019-08-22 10:47:41 +02:00

1361 lines
34 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/ceph/ceph_debug.h>
#include <linux/ceph/pagelist.h>
#include "super.h"
#include "mds_client.h"
#include <linux/ceph/decode.h>
#include <linux/xattr.h>
#include <linux/security.h>
#include <linux/posix_acl_xattr.h>
#include <linux/slab.h>
#define XATTR_CEPH_PREFIX "ceph."
#define XATTR_CEPH_PREFIX_LEN (sizeof (XATTR_CEPH_PREFIX) - 1)
static int __remove_xattr(struct ceph_inode_info *ci,
struct ceph_inode_xattr *xattr);
static bool ceph_is_valid_xattr(const char *name)
{
return !strncmp(name, XATTR_CEPH_PREFIX, XATTR_CEPH_PREFIX_LEN) ||
!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) ||
!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
}
/*
* These define virtual xattrs exposing the recursive directory
* statistics and layout metadata.
*/
struct ceph_vxattr {
char *name;
size_t name_size; /* strlen(name) + 1 (for '\0') */
ssize_t (*getxattr_cb)(struct ceph_inode_info *ci, char *val,
size_t size);
bool (*exists_cb)(struct ceph_inode_info *ci);
unsigned int flags;
};
#define VXATTR_FLAG_READONLY (1<<0)
#define VXATTR_FLAG_HIDDEN (1<<1)
#define VXATTR_FLAG_RSTAT (1<<2)
/* layouts */
static bool ceph_vxattrcb_layout_exists(struct ceph_inode_info *ci)
{
struct ceph_file_layout *fl = &ci->i_layout;
return (fl->stripe_unit > 0 || fl->stripe_count > 0 ||
fl->object_size > 0 || fl->pool_id >= 0 ||
rcu_dereference_raw(fl->pool_ns) != NULL);
}
static ssize_t ceph_vxattrcb_layout(struct ceph_inode_info *ci, char *val,
size_t size)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(ci->vfs_inode.i_sb);
struct ceph_osd_client *osdc = &fsc->client->osdc;
struct ceph_string *pool_ns;
s64 pool = ci->i_layout.pool_id;
const char *pool_name;
const char *ns_field = " pool_namespace=";
char buf[128];
size_t len, total_len = 0;
ssize_t ret;
pool_ns = ceph_try_get_string(ci->i_layout.pool_ns);
dout("ceph_vxattrcb_layout %p\n", &ci->vfs_inode);
down_read(&osdc->lock);
pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, pool);
if (pool_name) {
len = snprintf(buf, sizeof(buf),
"stripe_unit=%u stripe_count=%u object_size=%u pool=",
ci->i_layout.stripe_unit, ci->i_layout.stripe_count,
ci->i_layout.object_size);
total_len = len + strlen(pool_name);
} else {
len = snprintf(buf, sizeof(buf),
"stripe_unit=%u stripe_count=%u object_size=%u pool=%lld",
ci->i_layout.stripe_unit, ci->i_layout.stripe_count,
ci->i_layout.object_size, pool);
total_len = len;
}
if (pool_ns)
total_len += strlen(ns_field) + pool_ns->len;
ret = total_len;
if (size >= total_len) {
memcpy(val, buf, len);
ret = len;
if (pool_name) {
len = strlen(pool_name);
memcpy(val + ret, pool_name, len);
ret += len;
}
if (pool_ns) {
len = strlen(ns_field);
memcpy(val + ret, ns_field, len);
ret += len;
memcpy(val + ret, pool_ns->str, pool_ns->len);
ret += pool_ns->len;
}
}
up_read(&osdc->lock);
ceph_put_string(pool_ns);
return ret;
}
/*
* The convention with strings in xattrs is that they should not be NULL
* terminated, since we're returning the length with them. snprintf always
* NULL terminates however, so call it on a temporary buffer and then memcpy
* the result into place.
*/
static int ceph_fmt_xattr(char *val, size_t size, const char *fmt, ...)
{
int ret;
va_list args;
char buf[96]; /* NB: reevaluate size if new vxattrs are added */
va_start(args, fmt);
ret = vsnprintf(buf, size ? sizeof(buf) : 0, fmt, args);
va_end(args);
/* Sanity check */
if (size && ret + 1 > sizeof(buf)) {
WARN_ONCE(true, "Returned length too big (%d)", ret);
return -E2BIG;
}
if (ret <= size)
memcpy(val, buf, ret);
return ret;
}
static ssize_t ceph_vxattrcb_layout_stripe_unit(struct ceph_inode_info *ci,
char *val, size_t size)
{
return ceph_fmt_xattr(val, size, "%u", ci->i_layout.stripe_unit);
}
static ssize_t ceph_vxattrcb_layout_stripe_count(struct ceph_inode_info *ci,
char *val, size_t size)
{
return ceph_fmt_xattr(val, size, "%u", ci->i_layout.stripe_count);
}
static ssize_t ceph_vxattrcb_layout_object_size(struct ceph_inode_info *ci,
char *val, size_t size)
{
return ceph_fmt_xattr(val, size, "%u", ci->i_layout.object_size);
}
static ssize_t ceph_vxattrcb_layout_pool(struct ceph_inode_info *ci,
char *val, size_t size)
{
ssize_t ret;
struct ceph_fs_client *fsc = ceph_sb_to_client(ci->vfs_inode.i_sb);
struct ceph_osd_client *osdc = &fsc->client->osdc;
s64 pool = ci->i_layout.pool_id;
const char *pool_name;
down_read(&osdc->lock);
pool_name = ceph_pg_pool_name_by_id(osdc->osdmap, pool);
if (pool_name) {
ret = strlen(pool_name);
if (ret <= size)
memcpy(val, pool_name, ret);
} else {
ret = ceph_fmt_xattr(val, size, "%lld", pool);
}
up_read(&osdc->lock);
return ret;
}
static ssize_t ceph_vxattrcb_layout_pool_namespace(struct ceph_inode_info *ci,
char *val, size_t size)
{
ssize_t ret = 0;
struct ceph_string *ns = ceph_try_get_string(ci->i_layout.pool_ns);
if (ns) {
ret = ns->len;
if (ret <= size)
memcpy(val, ns->str, ret);
ceph_put_string(ns);
}
return ret;
}
/* directories */
static ssize_t ceph_vxattrcb_dir_entries(struct ceph_inode_info *ci, char *val,
size_t size)
{
return ceph_fmt_xattr(val, size, "%lld", ci->i_files + ci->i_subdirs);
}
static ssize_t ceph_vxattrcb_dir_files(struct ceph_inode_info *ci, char *val,
size_t size)
{
return ceph_fmt_xattr(val, size, "%lld", ci->i_files);
}
static ssize_t ceph_vxattrcb_dir_subdirs(struct ceph_inode_info *ci, char *val,
size_t size)
{
return ceph_fmt_xattr(val, size, "%lld", ci->i_subdirs);
}
static ssize_t ceph_vxattrcb_dir_rentries(struct ceph_inode_info *ci, char *val,
size_t size)
{
return ceph_fmt_xattr(val, size, "%lld",
ci->i_rfiles + ci->i_rsubdirs);
}
static ssize_t ceph_vxattrcb_dir_rfiles(struct ceph_inode_info *ci, char *val,
size_t size)
{
return ceph_fmt_xattr(val, size, "%lld", ci->i_rfiles);
}
static ssize_t ceph_vxattrcb_dir_rsubdirs(struct ceph_inode_info *ci, char *val,
size_t size)
{
return ceph_fmt_xattr(val, size, "%lld", ci->i_rsubdirs);
}
static ssize_t ceph_vxattrcb_dir_rbytes(struct ceph_inode_info *ci, char *val,
size_t size)
{
return ceph_fmt_xattr(val, size, "%lld", ci->i_rbytes);
}
static ssize_t ceph_vxattrcb_dir_rctime(struct ceph_inode_info *ci, char *val,
size_t size)
{
return ceph_fmt_xattr(val, size, "%lld.%09ld", ci->i_rctime.tv_sec,
ci->i_rctime.tv_nsec);
}
/* dir pin */
static bool ceph_vxattrcb_dir_pin_exists(struct ceph_inode_info *ci)
{
return ci->i_dir_pin != -ENODATA;
}
static ssize_t ceph_vxattrcb_dir_pin(struct ceph_inode_info *ci, char *val,
size_t size)
{
return ceph_fmt_xattr(val, size, "%d", (int)ci->i_dir_pin);
}
/* quotas */
static bool ceph_vxattrcb_quota_exists(struct ceph_inode_info *ci)
{
bool ret = false;
spin_lock(&ci->i_ceph_lock);
if ((ci->i_max_files || ci->i_max_bytes) &&
ci->i_vino.snap == CEPH_NOSNAP &&
ci->i_snap_realm &&
ci->i_snap_realm->ino == ci->i_vino.ino)
ret = true;
spin_unlock(&ci->i_ceph_lock);
return ret;
}
static ssize_t ceph_vxattrcb_quota(struct ceph_inode_info *ci, char *val,
size_t size)
{
return ceph_fmt_xattr(val, size, "max_bytes=%llu max_files=%llu",
ci->i_max_bytes, ci->i_max_files);
}
static ssize_t ceph_vxattrcb_quota_max_bytes(struct ceph_inode_info *ci,
char *val, size_t size)
{
return ceph_fmt_xattr(val, size, "%llu", ci->i_max_bytes);
}
static ssize_t ceph_vxattrcb_quota_max_files(struct ceph_inode_info *ci,
char *val, size_t size)
{
return ceph_fmt_xattr(val, size, "%llu", ci->i_max_files);
}
/* snapshots */
static bool ceph_vxattrcb_snap_btime_exists(struct ceph_inode_info *ci)
{
return (ci->i_snap_btime.tv_sec != 0 || ci->i_snap_btime.tv_nsec != 0);
}
static ssize_t ceph_vxattrcb_snap_btime(struct ceph_inode_info *ci, char *val,
size_t size)
{
return ceph_fmt_xattr(val, size, "%lld.%09ld", ci->i_snap_btime.tv_sec,
ci->i_snap_btime.tv_nsec);
}
#define CEPH_XATTR_NAME(_type, _name) XATTR_CEPH_PREFIX #_type "." #_name
#define CEPH_XATTR_NAME2(_type, _name, _name2) \
XATTR_CEPH_PREFIX #_type "." #_name "." #_name2
#define XATTR_NAME_CEPH(_type, _name, _flags) \
{ \
.name = CEPH_XATTR_NAME(_type, _name), \
.name_size = sizeof (CEPH_XATTR_NAME(_type, _name)), \
.getxattr_cb = ceph_vxattrcb_ ## _type ## _ ## _name, \
.exists_cb = NULL, \
.flags = (VXATTR_FLAG_READONLY | _flags), \
}
#define XATTR_RSTAT_FIELD(_type, _name) \
XATTR_NAME_CEPH(_type, _name, VXATTR_FLAG_RSTAT)
#define XATTR_LAYOUT_FIELD(_type, _name, _field) \
{ \
.name = CEPH_XATTR_NAME2(_type, _name, _field), \
.name_size = sizeof (CEPH_XATTR_NAME2(_type, _name, _field)), \
.getxattr_cb = ceph_vxattrcb_ ## _name ## _ ## _field, \
.exists_cb = ceph_vxattrcb_layout_exists, \
.flags = VXATTR_FLAG_HIDDEN, \
}
#define XATTR_QUOTA_FIELD(_type, _name) \
{ \
.name = CEPH_XATTR_NAME(_type, _name), \
.name_size = sizeof(CEPH_XATTR_NAME(_type, _name)), \
.getxattr_cb = ceph_vxattrcb_ ## _type ## _ ## _name, \
.exists_cb = ceph_vxattrcb_quota_exists, \
.flags = VXATTR_FLAG_HIDDEN, \
}
static struct ceph_vxattr ceph_dir_vxattrs[] = {
{
.name = "ceph.dir.layout",
.name_size = sizeof("ceph.dir.layout"),
.getxattr_cb = ceph_vxattrcb_layout,
.exists_cb = ceph_vxattrcb_layout_exists,
.flags = VXATTR_FLAG_HIDDEN,
},
XATTR_LAYOUT_FIELD(dir, layout, stripe_unit),
XATTR_LAYOUT_FIELD(dir, layout, stripe_count),
XATTR_LAYOUT_FIELD(dir, layout, object_size),
XATTR_LAYOUT_FIELD(dir, layout, pool),
XATTR_LAYOUT_FIELD(dir, layout, pool_namespace),
XATTR_NAME_CEPH(dir, entries, 0),
XATTR_NAME_CEPH(dir, files, 0),
XATTR_NAME_CEPH(dir, subdirs, 0),
XATTR_RSTAT_FIELD(dir, rentries),
XATTR_RSTAT_FIELD(dir, rfiles),
XATTR_RSTAT_FIELD(dir, rsubdirs),
XATTR_RSTAT_FIELD(dir, rbytes),
XATTR_RSTAT_FIELD(dir, rctime),
{
.name = "ceph.dir.pin",
.name_size = sizeof("ceph.dir.pin"),
.getxattr_cb = ceph_vxattrcb_dir_pin,
.exists_cb = ceph_vxattrcb_dir_pin_exists,
.flags = VXATTR_FLAG_HIDDEN,
},
{
.name = "ceph.quota",
.name_size = sizeof("ceph.quota"),
.getxattr_cb = ceph_vxattrcb_quota,
.exists_cb = ceph_vxattrcb_quota_exists,
.flags = VXATTR_FLAG_HIDDEN,
},
XATTR_QUOTA_FIELD(quota, max_bytes),
XATTR_QUOTA_FIELD(quota, max_files),
{
.name = "ceph.snap.btime",
.name_size = sizeof("ceph.snap.btime"),
.getxattr_cb = ceph_vxattrcb_snap_btime,
.exists_cb = ceph_vxattrcb_snap_btime_exists,
.flags = VXATTR_FLAG_READONLY,
},
{ .name = NULL, 0 } /* Required table terminator */
};
/* files */
static struct ceph_vxattr ceph_file_vxattrs[] = {
{
.name = "ceph.file.layout",
.name_size = sizeof("ceph.file.layout"),
.getxattr_cb = ceph_vxattrcb_layout,
.exists_cb = ceph_vxattrcb_layout_exists,
.flags = VXATTR_FLAG_HIDDEN,
},
XATTR_LAYOUT_FIELD(file, layout, stripe_unit),
XATTR_LAYOUT_FIELD(file, layout, stripe_count),
XATTR_LAYOUT_FIELD(file, layout, object_size),
XATTR_LAYOUT_FIELD(file, layout, pool),
XATTR_LAYOUT_FIELD(file, layout, pool_namespace),
{
.name = "ceph.snap.btime",
.name_size = sizeof("ceph.snap.btime"),
.getxattr_cb = ceph_vxattrcb_snap_btime,
.exists_cb = ceph_vxattrcb_snap_btime_exists,
.flags = VXATTR_FLAG_READONLY,
},
{ .name = NULL, 0 } /* Required table terminator */
};
static struct ceph_vxattr *ceph_inode_vxattrs(struct inode *inode)
{
if (S_ISDIR(inode->i_mode))
return ceph_dir_vxattrs;
else if (S_ISREG(inode->i_mode))
return ceph_file_vxattrs;
return NULL;
}
static struct ceph_vxattr *ceph_match_vxattr(struct inode *inode,
const char *name)
{
struct ceph_vxattr *vxattr = ceph_inode_vxattrs(inode);
if (vxattr) {
while (vxattr->name) {
if (!strcmp(vxattr->name, name))
return vxattr;
vxattr++;
}
}
return NULL;
}
static int __set_xattr(struct ceph_inode_info *ci,
const char *name, int name_len,
const char *val, int val_len,
int flags, int update_xattr,
struct ceph_inode_xattr **newxattr)
{
struct rb_node **p;
struct rb_node *parent = NULL;
struct ceph_inode_xattr *xattr = NULL;
int c;
int new = 0;
p = &ci->i_xattrs.index.rb_node;
while (*p) {
parent = *p;
xattr = rb_entry(parent, struct ceph_inode_xattr, node);
c = strncmp(name, xattr->name, min(name_len, xattr->name_len));
if (c < 0)
p = &(*p)->rb_left;
else if (c > 0)
p = &(*p)->rb_right;
else {
if (name_len == xattr->name_len)
break;
else if (name_len < xattr->name_len)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
xattr = NULL;
}
if (update_xattr) {
int err = 0;
if (xattr && (flags & XATTR_CREATE))
err = -EEXIST;
else if (!xattr && (flags & XATTR_REPLACE))
err = -ENODATA;
if (err) {
kfree(name);
kfree(val);
kfree(*newxattr);
return err;
}
if (update_xattr < 0) {
if (xattr)
__remove_xattr(ci, xattr);
kfree(name);
kfree(*newxattr);
return 0;
}
}
if (!xattr) {
new = 1;
xattr = *newxattr;
xattr->name = name;
xattr->name_len = name_len;
xattr->should_free_name = update_xattr;
ci->i_xattrs.count++;
dout("__set_xattr count=%d\n", ci->i_xattrs.count);
} else {
kfree(*newxattr);
*newxattr = NULL;
if (xattr->should_free_val)
kfree((void *)xattr->val);
if (update_xattr) {
kfree((void *)name);
name = xattr->name;
}
ci->i_xattrs.names_size -= xattr->name_len;
ci->i_xattrs.vals_size -= xattr->val_len;
}
ci->i_xattrs.names_size += name_len;
ci->i_xattrs.vals_size += val_len;
if (val)
xattr->val = val;
else
xattr->val = "";
xattr->val_len = val_len;
xattr->dirty = update_xattr;
xattr->should_free_val = (val && update_xattr);
if (new) {
rb_link_node(&xattr->node, parent, p);
rb_insert_color(&xattr->node, &ci->i_xattrs.index);
dout("__set_xattr_val p=%p\n", p);
}
dout("__set_xattr_val added %llx.%llx xattr %p %.*s=%.*s\n",
ceph_vinop(&ci->vfs_inode), xattr, name_len, name, val_len, val);
return 0;
}
static struct ceph_inode_xattr *__get_xattr(struct ceph_inode_info *ci,
const char *name)
{
struct rb_node **p;
struct rb_node *parent = NULL;
struct ceph_inode_xattr *xattr = NULL;
int name_len = strlen(name);
int c;
p = &ci->i_xattrs.index.rb_node;
while (*p) {
parent = *p;
xattr = rb_entry(parent, struct ceph_inode_xattr, node);
c = strncmp(name, xattr->name, xattr->name_len);
if (c == 0 && name_len > xattr->name_len)
c = 1;
if (c < 0)
p = &(*p)->rb_left;
else if (c > 0)
p = &(*p)->rb_right;
else {
dout("__get_xattr %s: found %.*s\n", name,
xattr->val_len, xattr->val);
return xattr;
}
}
dout("__get_xattr %s: not found\n", name);
return NULL;
}
static void __free_xattr(struct ceph_inode_xattr *xattr)
{
BUG_ON(!xattr);
if (xattr->should_free_name)
kfree((void *)xattr->name);
if (xattr->should_free_val)
kfree((void *)xattr->val);
kfree(xattr);
}
static int __remove_xattr(struct ceph_inode_info *ci,
struct ceph_inode_xattr *xattr)
{
if (!xattr)
return -ENODATA;
rb_erase(&xattr->node, &ci->i_xattrs.index);
if (xattr->should_free_name)
kfree((void *)xattr->name);
if (xattr->should_free_val)
kfree((void *)xattr->val);
ci->i_xattrs.names_size -= xattr->name_len;
ci->i_xattrs.vals_size -= xattr->val_len;
ci->i_xattrs.count--;
kfree(xattr);
return 0;
}
static char *__copy_xattr_names(struct ceph_inode_info *ci,
char *dest)
{
struct rb_node *p;
struct ceph_inode_xattr *xattr = NULL;
p = rb_first(&ci->i_xattrs.index);
dout("__copy_xattr_names count=%d\n", ci->i_xattrs.count);
while (p) {
xattr = rb_entry(p, struct ceph_inode_xattr, node);
memcpy(dest, xattr->name, xattr->name_len);
dest[xattr->name_len] = '\0';
dout("dest=%s %p (%s) (%d/%d)\n", dest, xattr, xattr->name,
xattr->name_len, ci->i_xattrs.names_size);
dest += xattr->name_len + 1;
p = rb_next(p);
}
return dest;
}
void __ceph_destroy_xattrs(struct ceph_inode_info *ci)
{
struct rb_node *p, *tmp;
struct ceph_inode_xattr *xattr = NULL;
p = rb_first(&ci->i_xattrs.index);
dout("__ceph_destroy_xattrs p=%p\n", p);
while (p) {
xattr = rb_entry(p, struct ceph_inode_xattr, node);
tmp = p;
p = rb_next(tmp);
dout("__ceph_destroy_xattrs next p=%p (%.*s)\n", p,
xattr->name_len, xattr->name);
rb_erase(tmp, &ci->i_xattrs.index);
__free_xattr(xattr);
}
ci->i_xattrs.names_size = 0;
ci->i_xattrs.vals_size = 0;
ci->i_xattrs.index_version = 0;
ci->i_xattrs.count = 0;
ci->i_xattrs.index = RB_ROOT;
}
static int __build_xattrs(struct inode *inode)
__releases(ci->i_ceph_lock)
__acquires(ci->i_ceph_lock)
{
u32 namelen;
u32 numattr = 0;
void *p, *end;
u32 len;
const char *name, *val;
struct ceph_inode_info *ci = ceph_inode(inode);
int xattr_version;
struct ceph_inode_xattr **xattrs = NULL;
int err = 0;
int i;
dout("__build_xattrs() len=%d\n",
ci->i_xattrs.blob ? (int)ci->i_xattrs.blob->vec.iov_len : 0);
if (ci->i_xattrs.index_version >= ci->i_xattrs.version)
return 0; /* already built */
__ceph_destroy_xattrs(ci);
start:
/* updated internal xattr rb tree */
if (ci->i_xattrs.blob && ci->i_xattrs.blob->vec.iov_len > 4) {
p = ci->i_xattrs.blob->vec.iov_base;
end = p + ci->i_xattrs.blob->vec.iov_len;
ceph_decode_32_safe(&p, end, numattr, bad);
xattr_version = ci->i_xattrs.version;
spin_unlock(&ci->i_ceph_lock);
xattrs = kcalloc(numattr, sizeof(struct ceph_inode_xattr *),
GFP_NOFS);
err = -ENOMEM;
if (!xattrs)
goto bad_lock;
for (i = 0; i < numattr; i++) {
xattrs[i] = kmalloc(sizeof(struct ceph_inode_xattr),
GFP_NOFS);
if (!xattrs[i])
goto bad_lock;
}
spin_lock(&ci->i_ceph_lock);
if (ci->i_xattrs.version != xattr_version) {
/* lost a race, retry */
for (i = 0; i < numattr; i++)
kfree(xattrs[i]);
kfree(xattrs);
xattrs = NULL;
goto start;
}
err = -EIO;
while (numattr--) {
ceph_decode_32_safe(&p, end, len, bad);
namelen = len;
name = p;
p += len;
ceph_decode_32_safe(&p, end, len, bad);
val = p;
p += len;
err = __set_xattr(ci, name, namelen, val, len,
0, 0, &xattrs[numattr]);
if (err < 0)
goto bad;
}
kfree(xattrs);
}
ci->i_xattrs.index_version = ci->i_xattrs.version;
ci->i_xattrs.dirty = false;
return err;
bad_lock:
spin_lock(&ci->i_ceph_lock);
bad:
if (xattrs) {
for (i = 0; i < numattr; i++)
kfree(xattrs[i]);
kfree(xattrs);
}
ci->i_xattrs.names_size = 0;
return err;
}
static int __get_required_blob_size(struct ceph_inode_info *ci, int name_size,
int val_size)
{
/*
* 4 bytes for the length, and additional 4 bytes per each xattr name,
* 4 bytes per each value
*/
int size = 4 + ci->i_xattrs.count*(4 + 4) +
ci->i_xattrs.names_size +
ci->i_xattrs.vals_size;
dout("__get_required_blob_size c=%d names.size=%d vals.size=%d\n",
ci->i_xattrs.count, ci->i_xattrs.names_size,
ci->i_xattrs.vals_size);
if (name_size)
size += 4 + 4 + name_size + val_size;
return size;
}
/*
* If there are dirty xattrs, reencode xattrs into the prealloc_blob
* and swap into place. It returns the old i_xattrs.blob (or NULL) so
* that it can be freed by the caller as the i_ceph_lock is likely to be
* held.
*/
struct ceph_buffer *__ceph_build_xattrs_blob(struct ceph_inode_info *ci)
{
struct rb_node *p;
struct ceph_inode_xattr *xattr = NULL;
struct ceph_buffer *old_blob = NULL;
void *dest;
dout("__build_xattrs_blob %p\n", &ci->vfs_inode);
if (ci->i_xattrs.dirty) {
int need = __get_required_blob_size(ci, 0, 0);
BUG_ON(need > ci->i_xattrs.prealloc_blob->alloc_len);
p = rb_first(&ci->i_xattrs.index);
dest = ci->i_xattrs.prealloc_blob->vec.iov_base;
ceph_encode_32(&dest, ci->i_xattrs.count);
while (p) {
xattr = rb_entry(p, struct ceph_inode_xattr, node);
ceph_encode_32(&dest, xattr->name_len);
memcpy(dest, xattr->name, xattr->name_len);
dest += xattr->name_len;
ceph_encode_32(&dest, xattr->val_len);
memcpy(dest, xattr->val, xattr->val_len);
dest += xattr->val_len;
p = rb_next(p);
}
/* adjust buffer len; it may be larger than we need */
ci->i_xattrs.prealloc_blob->vec.iov_len =
dest - ci->i_xattrs.prealloc_blob->vec.iov_base;
if (ci->i_xattrs.blob)
old_blob = ci->i_xattrs.blob;
ci->i_xattrs.blob = ci->i_xattrs.prealloc_blob;
ci->i_xattrs.prealloc_blob = NULL;
ci->i_xattrs.dirty = false;
ci->i_xattrs.version++;
}
return old_blob;
}
static inline int __get_request_mask(struct inode *in) {
struct ceph_mds_request *req = current->journal_info;
int mask = 0;
if (req && req->r_target_inode == in) {
if (req->r_op == CEPH_MDS_OP_LOOKUP ||
req->r_op == CEPH_MDS_OP_LOOKUPINO ||
req->r_op == CEPH_MDS_OP_LOOKUPPARENT ||
req->r_op == CEPH_MDS_OP_GETATTR) {
mask = le32_to_cpu(req->r_args.getattr.mask);
} else if (req->r_op == CEPH_MDS_OP_OPEN ||
req->r_op == CEPH_MDS_OP_CREATE) {
mask = le32_to_cpu(req->r_args.open.mask);
}
}
return mask;
}
ssize_t __ceph_getxattr(struct inode *inode, const char *name, void *value,
size_t size)
{
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_inode_xattr *xattr;
struct ceph_vxattr *vxattr = NULL;
int req_mask;
ssize_t err;
/* let's see if a virtual xattr was requested */
vxattr = ceph_match_vxattr(inode, name);
if (vxattr) {
int mask = 0;
if (vxattr->flags & VXATTR_FLAG_RSTAT)
mask |= CEPH_STAT_RSTAT;
err = ceph_do_getattr(inode, mask, true);
if (err)
return err;
err = -ENODATA;
if (!(vxattr->exists_cb && !vxattr->exists_cb(ci))) {
err = vxattr->getxattr_cb(ci, value, size);
if (size && size < err)
err = -ERANGE;
}
return err;
}
req_mask = __get_request_mask(inode);
spin_lock(&ci->i_ceph_lock);
dout("getxattr %p ver=%lld index_ver=%lld\n", inode,
ci->i_xattrs.version, ci->i_xattrs.index_version);
if (ci->i_xattrs.version == 0 ||
!((req_mask & CEPH_CAP_XATTR_SHARED) ||
__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 1))) {
spin_unlock(&ci->i_ceph_lock);
/* security module gets xattr while filling trace */
if (current->journal_info) {
pr_warn_ratelimited("sync getxattr %p "
"during filling trace\n", inode);
return -EBUSY;
}
/* get xattrs from mds (if we don't already have them) */
err = ceph_do_getattr(inode, CEPH_STAT_CAP_XATTR, true);
if (err)
return err;
spin_lock(&ci->i_ceph_lock);
}
err = __build_xattrs(inode);
if (err < 0)
goto out;
err = -ENODATA; /* == ENOATTR */
xattr = __get_xattr(ci, name);
if (!xattr)
goto out;
err = -ERANGE;
if (size && size < xattr->val_len)
goto out;
err = xattr->val_len;
if (size == 0)
goto out;
memcpy(value, xattr->val, xattr->val_len);
if (current->journal_info &&
!strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN))
ci->i_ceph_flags |= CEPH_I_SEC_INITED;
out:
spin_unlock(&ci->i_ceph_lock);
return err;
}
ssize_t ceph_listxattr(struct dentry *dentry, char *names, size_t size)
{
struct inode *inode = d_inode(dentry);
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_vxattr *vxattrs = ceph_inode_vxattrs(inode);
bool len_only = (size == 0);
u32 namelen;
int err;
int i;
spin_lock(&ci->i_ceph_lock);
dout("listxattr %p ver=%lld index_ver=%lld\n", inode,
ci->i_xattrs.version, ci->i_xattrs.index_version);
if (ci->i_xattrs.version == 0 ||
!__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 1)) {
spin_unlock(&ci->i_ceph_lock);
err = ceph_do_getattr(inode, CEPH_STAT_CAP_XATTR, true);
if (err)
return err;
spin_lock(&ci->i_ceph_lock);
}
err = __build_xattrs(inode);
if (err < 0)
goto out;
/* add 1 byte for each xattr due to the null termination */
namelen = ci->i_xattrs.names_size + ci->i_xattrs.count;
if (!len_only) {
if (namelen > size) {
err = -ERANGE;
goto out;
}
names = __copy_xattr_names(ci, names);
size -= namelen;
}
/* virtual xattr names, too */
if (vxattrs) {
for (i = 0; vxattrs[i].name; i++) {
size_t this_len;
if (vxattrs[i].flags & VXATTR_FLAG_HIDDEN)
continue;
if (vxattrs[i].exists_cb && !vxattrs[i].exists_cb(ci))
continue;
this_len = strlen(vxattrs[i].name) + 1;
namelen += this_len;
if (len_only)
continue;
if (this_len > size) {
err = -ERANGE;
goto out;
}
memcpy(names, vxattrs[i].name, this_len);
names += this_len;
size -= this_len;
}
}
err = namelen;
out:
spin_unlock(&ci->i_ceph_lock);
return err;
}
static int ceph_sync_setxattr(struct inode *inode, const char *name,
const char *value, size_t size, int flags)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_mds_request *req;
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_pagelist *pagelist = NULL;
int op = CEPH_MDS_OP_SETXATTR;
int err;
if (size > 0) {
/* copy value into pagelist */
pagelist = ceph_pagelist_alloc(GFP_NOFS);
if (!pagelist)
return -ENOMEM;
err = ceph_pagelist_append(pagelist, value, size);
if (err)
goto out;
} else if (!value) {
if (flags & CEPH_XATTR_REPLACE)
op = CEPH_MDS_OP_RMXATTR;
else
flags |= CEPH_XATTR_REMOVE;
}
dout("setxattr value=%.*s\n", (int)size, value);
/* do request */
req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
if (IS_ERR(req)) {
err = PTR_ERR(req);
goto out;
}
req->r_path2 = kstrdup(name, GFP_NOFS);
if (!req->r_path2) {
ceph_mdsc_put_request(req);
err = -ENOMEM;
goto out;
}
if (op == CEPH_MDS_OP_SETXATTR) {
req->r_args.setxattr.flags = cpu_to_le32(flags);
req->r_pagelist = pagelist;
pagelist = NULL;
}
req->r_inode = inode;
ihold(inode);
req->r_num_caps = 1;
req->r_inode_drop = CEPH_CAP_XATTR_SHARED;
dout("xattr.ver (before): %lld\n", ci->i_xattrs.version);
err = ceph_mdsc_do_request(mdsc, NULL, req);
ceph_mdsc_put_request(req);
dout("xattr.ver (after): %lld\n", ci->i_xattrs.version);
out:
if (pagelist)
ceph_pagelist_release(pagelist);
return err;
}
int __ceph_setxattr(struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
struct ceph_vxattr *vxattr;
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_mds_client *mdsc = ceph_sb_to_client(inode->i_sb)->mdsc;
struct ceph_cap_flush *prealloc_cf = NULL;
struct ceph_buffer *old_blob = NULL;
int issued;
int err;
int dirty = 0;
int name_len = strlen(name);
int val_len = size;
char *newname = NULL;
char *newval = NULL;
struct ceph_inode_xattr *xattr = NULL;
int required_blob_size;
bool check_realm = false;
bool lock_snap_rwsem = false;
if (ceph_snap(inode) != CEPH_NOSNAP)
return -EROFS;
vxattr = ceph_match_vxattr(inode, name);
if (vxattr) {
if (vxattr->flags & VXATTR_FLAG_READONLY)
return -EOPNOTSUPP;
if (value && !strncmp(vxattr->name, "ceph.quota", 10))
check_realm = true;
}
/* pass any unhandled ceph.* xattrs through to the MDS */
if (!strncmp(name, XATTR_CEPH_PREFIX, XATTR_CEPH_PREFIX_LEN))
goto do_sync_unlocked;
/* preallocate memory for xattr name, value, index node */
err = -ENOMEM;
newname = kmemdup(name, name_len + 1, GFP_NOFS);
if (!newname)
goto out;
if (val_len) {
newval = kmemdup(value, val_len, GFP_NOFS);
if (!newval)
goto out;
}
xattr = kmalloc(sizeof(struct ceph_inode_xattr), GFP_NOFS);
if (!xattr)
goto out;
prealloc_cf = ceph_alloc_cap_flush();
if (!prealloc_cf)
goto out;
spin_lock(&ci->i_ceph_lock);
retry:
issued = __ceph_caps_issued(ci, NULL);
if (ci->i_xattrs.version == 0 || !(issued & CEPH_CAP_XATTR_EXCL))
goto do_sync;
if (!lock_snap_rwsem && !ci->i_head_snapc) {
lock_snap_rwsem = true;
if (!down_read_trylock(&mdsc->snap_rwsem)) {
spin_unlock(&ci->i_ceph_lock);
down_read(&mdsc->snap_rwsem);
spin_lock(&ci->i_ceph_lock);
goto retry;
}
}
dout("setxattr %p issued %s\n", inode, ceph_cap_string(issued));
__build_xattrs(inode);
required_blob_size = __get_required_blob_size(ci, name_len, val_len);
if (!ci->i_xattrs.prealloc_blob ||
required_blob_size > ci->i_xattrs.prealloc_blob->alloc_len) {
struct ceph_buffer *blob;
spin_unlock(&ci->i_ceph_lock);
ceph_buffer_put(old_blob); /* Shouldn't be required */
dout(" pre-allocating new blob size=%d\n", required_blob_size);
blob = ceph_buffer_new(required_blob_size, GFP_NOFS);
if (!blob)
goto do_sync_unlocked;
spin_lock(&ci->i_ceph_lock);
/* prealloc_blob can't be released while holding i_ceph_lock */
if (ci->i_xattrs.prealloc_blob)
old_blob = ci->i_xattrs.prealloc_blob;
ci->i_xattrs.prealloc_blob = blob;
goto retry;
}
err = __set_xattr(ci, newname, name_len, newval, val_len,
flags, value ? 1 : -1, &xattr);
if (!err) {
dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_XATTR_EXCL,
&prealloc_cf);
ci->i_xattrs.dirty = true;
inode->i_ctime = current_time(inode);
}
spin_unlock(&ci->i_ceph_lock);
ceph_buffer_put(old_blob);
if (lock_snap_rwsem)
up_read(&mdsc->snap_rwsem);
if (dirty)
__mark_inode_dirty(inode, dirty);
ceph_free_cap_flush(prealloc_cf);
return err;
do_sync:
spin_unlock(&ci->i_ceph_lock);
do_sync_unlocked:
if (lock_snap_rwsem)
up_read(&mdsc->snap_rwsem);
/* security module set xattr while filling trace */
if (current->journal_info) {
pr_warn_ratelimited("sync setxattr %p "
"during filling trace\n", inode);
err = -EBUSY;
} else {
err = ceph_sync_setxattr(inode, name, value, size, flags);
if (err >= 0 && check_realm) {
/* check if snaprealm was created for quota inode */
spin_lock(&ci->i_ceph_lock);
if ((ci->i_max_files || ci->i_max_bytes) &&
!(ci->i_snap_realm &&
ci->i_snap_realm->ino == ci->i_vino.ino))
err = -EOPNOTSUPP;
spin_unlock(&ci->i_ceph_lock);
}
}
out:
ceph_free_cap_flush(prealloc_cf);
kfree(newname);
kfree(newval);
kfree(xattr);
return err;
}
static int ceph_get_xattr_handler(const struct xattr_handler *handler,
struct dentry *dentry, struct inode *inode,
const char *name, void *value, size_t size)
{
if (!ceph_is_valid_xattr(name))
return -EOPNOTSUPP;
return __ceph_getxattr(inode, name, value, size);
}
static int ceph_set_xattr_handler(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
const char *name, const void *value,
size_t size, int flags)
{
if (!ceph_is_valid_xattr(name))
return -EOPNOTSUPP;
return __ceph_setxattr(inode, name, value, size, flags);
}
static const struct xattr_handler ceph_other_xattr_handler = {
.prefix = "", /* match any name => handlers called with full name */
.get = ceph_get_xattr_handler,
.set = ceph_set_xattr_handler,
};
#ifdef CONFIG_SECURITY
bool ceph_security_xattr_wanted(struct inode *in)
{
return in->i_security != NULL;
}
bool ceph_security_xattr_deadlock(struct inode *in)
{
struct ceph_inode_info *ci;
bool ret;
if (!in->i_security)
return false;
ci = ceph_inode(in);
spin_lock(&ci->i_ceph_lock);
ret = !(ci->i_ceph_flags & CEPH_I_SEC_INITED) &&
!(ci->i_xattrs.version > 0 &&
__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 0));
spin_unlock(&ci->i_ceph_lock);
return ret;
}
#ifdef CONFIG_CEPH_FS_SECURITY_LABEL
int ceph_security_init_secctx(struct dentry *dentry, umode_t mode,
struct ceph_acl_sec_ctx *as_ctx)
{
struct ceph_pagelist *pagelist = as_ctx->pagelist;
const char *name;
size_t name_len;
int err;
err = security_dentry_init_security(dentry, mode, &dentry->d_name,
&as_ctx->sec_ctx,
&as_ctx->sec_ctxlen);
if (err < 0) {
WARN_ON_ONCE(err != -EOPNOTSUPP);
err = 0; /* do nothing */
goto out;
}
err = -ENOMEM;
if (!pagelist) {
pagelist = ceph_pagelist_alloc(GFP_KERNEL);
if (!pagelist)
goto out;
err = ceph_pagelist_reserve(pagelist, PAGE_SIZE);
if (err)
goto out;
ceph_pagelist_encode_32(pagelist, 1);
}
/*
* FIXME: Make security_dentry_init_security() generic. Currently
* It only supports single security module and only selinux has
* dentry_init_security hook.
*/
name = XATTR_NAME_SELINUX;
name_len = strlen(name);
err = ceph_pagelist_reserve(pagelist,
4 * 2 + name_len + as_ctx->sec_ctxlen);
if (err)
goto out;
if (as_ctx->pagelist) {
/* update count of KV pairs */
BUG_ON(pagelist->length <= sizeof(__le32));
if (list_is_singular(&pagelist->head)) {
le32_add_cpu((__le32*)pagelist->mapped_tail, 1);
} else {
struct page *page = list_first_entry(&pagelist->head,
struct page, lru);
void *addr = kmap_atomic(page);
le32_add_cpu((__le32*)addr, 1);
kunmap_atomic(addr);
}
} else {
as_ctx->pagelist = pagelist;
}
ceph_pagelist_encode_32(pagelist, name_len);
ceph_pagelist_append(pagelist, name, name_len);
ceph_pagelist_encode_32(pagelist, as_ctx->sec_ctxlen);
ceph_pagelist_append(pagelist, as_ctx->sec_ctx, as_ctx->sec_ctxlen);
err = 0;
out:
if (pagelist && !as_ctx->pagelist)
ceph_pagelist_release(pagelist);
return err;
}
void ceph_security_invalidate_secctx(struct inode *inode)
{
security_inode_invalidate_secctx(inode);
}
static int ceph_xattr_set_security_label(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
const char *key, const void *buf,
size_t buflen, int flags)
{
if (security_ismaclabel(key)) {
const char *name = xattr_full_name(handler, key);
return __ceph_setxattr(inode, name, buf, buflen, flags);
}
return -EOPNOTSUPP;
}
static int ceph_xattr_get_security_label(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
const char *key, void *buf, size_t buflen)
{
if (security_ismaclabel(key)) {
const char *name = xattr_full_name(handler, key);
return __ceph_getxattr(inode, name, buf, buflen);
}
return -EOPNOTSUPP;
}
static const struct xattr_handler ceph_security_label_handler = {
.prefix = XATTR_SECURITY_PREFIX,
.get = ceph_xattr_get_security_label,
.set = ceph_xattr_set_security_label,
};
#endif
#endif
void ceph_release_acl_sec_ctx(struct ceph_acl_sec_ctx *as_ctx)
{
#ifdef CONFIG_CEPH_FS_POSIX_ACL
posix_acl_release(as_ctx->acl);
posix_acl_release(as_ctx->default_acl);
#endif
#ifdef CONFIG_CEPH_FS_SECURITY_LABEL
security_release_secctx(as_ctx->sec_ctx, as_ctx->sec_ctxlen);
#endif
if (as_ctx->pagelist)
ceph_pagelist_release(as_ctx->pagelist);
}
/*
* List of handlers for synthetic system.* attributes. Other
* attributes are handled directly.
*/
const struct xattr_handler *ceph_xattr_handlers[] = {
#ifdef CONFIG_CEPH_FS_POSIX_ACL
&posix_acl_access_xattr_handler,
&posix_acl_default_xattr_handler,
#endif
#ifdef CONFIG_CEPH_FS_SECURITY_LABEL
&ceph_security_label_handler,
#endif
&ceph_other_xattr_handler,
NULL,
};