Revision 98bda63e20daab95bdc084ce00459a4f622a0505 authored by Roman Kiryanov on 19 February 2020, 21:40:06 UTC, committed by David S. Miller on 20 February 2020, 23:02:02 UTC
The description says 'If unsure, say N.' but the module is built as M by default (once the dependencies are satisfied). When the module is selected (Y or M), it enables NETFILTER_FAMILY_BRIDGE and SKB_EXTENSIONS which alter kernel internal structures. We (Android Studio Emulator) currently do not use this module and think this it is more consistent to have it disabled by default as opposite to disabling it explicitly to prevent enabling NETFILTER_FAMILY_BRIDGE and SKB_EXTENSIONS. Signed-off-by: Roman Kiryanov <rkir@google.com> Acked-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent ac2fcfa
super.c
/* AFS superblock handling
*
* Copyright (c) 2002, 2007, 2018 Red Hat, Inc. All rights reserved.
*
* This software may be freely redistributed under the terms of the
* GNU General Public License.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Authors: David Howells <dhowells@redhat.com>
* David Woodhouse <dwmw2@infradead.org>
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/fs_parser.h>
#include <linux/statfs.h>
#include <linux/sched.h>
#include <linux/nsproxy.h>
#include <linux/magic.h>
#include <net/net_namespace.h>
#include "internal.h"
static void afs_i_init_once(void *foo);
static void afs_kill_super(struct super_block *sb);
static struct inode *afs_alloc_inode(struct super_block *sb);
static void afs_destroy_inode(struct inode *inode);
static void afs_free_inode(struct inode *inode);
static int afs_statfs(struct dentry *dentry, struct kstatfs *buf);
static int afs_show_devname(struct seq_file *m, struct dentry *root);
static int afs_show_options(struct seq_file *m, struct dentry *root);
static int afs_init_fs_context(struct fs_context *fc);
static const struct fs_parameter_spec afs_fs_parameters[];
struct file_system_type afs_fs_type = {
.owner = THIS_MODULE,
.name = "afs",
.init_fs_context = afs_init_fs_context,
.parameters = afs_fs_parameters,
.kill_sb = afs_kill_super,
.fs_flags = FS_RENAME_DOES_D_MOVE,
};
MODULE_ALIAS_FS("afs");
int afs_net_id;
static const struct super_operations afs_super_ops = {
.statfs = afs_statfs,
.alloc_inode = afs_alloc_inode,
.drop_inode = afs_drop_inode,
.destroy_inode = afs_destroy_inode,
.free_inode = afs_free_inode,
.evict_inode = afs_evict_inode,
.show_devname = afs_show_devname,
.show_options = afs_show_options,
};
static struct kmem_cache *afs_inode_cachep;
static atomic_t afs_count_active_inodes;
enum afs_param {
Opt_autocell,
Opt_dyn,
Opt_flock,
Opt_source,
};
static const struct constant_table afs_param_flock[] = {
{"local", afs_flock_mode_local },
{"openafs", afs_flock_mode_openafs },
{"strict", afs_flock_mode_strict },
{"write", afs_flock_mode_write },
{}
};
static const struct fs_parameter_spec afs_fs_parameters[] = {
fsparam_flag ("autocell", Opt_autocell),
fsparam_flag ("dyn", Opt_dyn),
fsparam_enum ("flock", Opt_flock, afs_param_flock),
fsparam_string("source", Opt_source),
{}
};
/*
* initialise the filesystem
*/
int __init afs_fs_init(void)
{
int ret;
_enter("");
/* create ourselves an inode cache */
atomic_set(&afs_count_active_inodes, 0);
ret = -ENOMEM;
afs_inode_cachep = kmem_cache_create("afs_inode_cache",
sizeof(struct afs_vnode),
0,
SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
afs_i_init_once);
if (!afs_inode_cachep) {
printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n");
return ret;
}
/* now export our filesystem to lesser mortals */
ret = register_filesystem(&afs_fs_type);
if (ret < 0) {
kmem_cache_destroy(afs_inode_cachep);
_leave(" = %d", ret);
return ret;
}
_leave(" = 0");
return 0;
}
/*
* clean up the filesystem
*/
void afs_fs_exit(void)
{
_enter("");
afs_mntpt_kill_timer();
unregister_filesystem(&afs_fs_type);
if (atomic_read(&afs_count_active_inodes) != 0) {
printk("kAFS: %d active inode objects still present\n",
atomic_read(&afs_count_active_inodes));
BUG();
}
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(afs_inode_cachep);
_leave("");
}
/*
* Display the mount device name in /proc/mounts.
*/
static int afs_show_devname(struct seq_file *m, struct dentry *root)
{
struct afs_super_info *as = AFS_FS_S(root->d_sb);
struct afs_volume *volume = as->volume;
struct afs_cell *cell = as->cell;
const char *suf = "";
char pref = '%';
if (as->dyn_root) {
seq_puts(m, "none");
return 0;
}
switch (volume->type) {
case AFSVL_RWVOL:
break;
case AFSVL_ROVOL:
pref = '#';
if (volume->type_force)
suf = ".readonly";
break;
case AFSVL_BACKVOL:
pref = '#';
suf = ".backup";
break;
}
seq_printf(m, "%c%s:%s%s", pref, cell->name, volume->name, suf);
return 0;
}
/*
* Display the mount options in /proc/mounts.
*/
static int afs_show_options(struct seq_file *m, struct dentry *root)
{
struct afs_super_info *as = AFS_FS_S(root->d_sb);
const char *p = NULL;
if (as->dyn_root)
seq_puts(m, ",dyn");
if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags))
seq_puts(m, ",autocell");
switch (as->flock_mode) {
case afs_flock_mode_unset: break;
case afs_flock_mode_local: p = "local"; break;
case afs_flock_mode_openafs: p = "openafs"; break;
case afs_flock_mode_strict: p = "strict"; break;
case afs_flock_mode_write: p = "write"; break;
}
if (p)
seq_printf(m, ",flock=%s", p);
return 0;
}
/*
* Parse the source name to get cell name, volume name, volume type and R/W
* selector.
*
* This can be one of the following:
* "%[cell:]volume[.]" R/W volume
* "#[cell:]volume[.]" R/O or R/W volume (R/O parent),
* or R/W (R/W parent) volume
* "%[cell:]volume.readonly" R/O volume
* "#[cell:]volume.readonly" R/O volume
* "%[cell:]volume.backup" Backup volume
* "#[cell:]volume.backup" Backup volume
*/
static int afs_parse_source(struct fs_context *fc, struct fs_parameter *param)
{
struct afs_fs_context *ctx = fc->fs_private;
struct afs_cell *cell;
const char *cellname, *suffix, *name = param->string;
int cellnamesz;
_enter(",%s", name);
if (!name) {
printk(KERN_ERR "kAFS: no volume name specified\n");
return -EINVAL;
}
if ((name[0] != '%' && name[0] != '#') || !name[1]) {
/* To use dynroot, we don't want to have to provide a source */
if (strcmp(name, "none") == 0) {
ctx->no_cell = true;
return 0;
}
printk(KERN_ERR "kAFS: unparsable volume name\n");
return -EINVAL;
}
/* determine the type of volume we're looking for */
if (name[0] == '%') {
ctx->type = AFSVL_RWVOL;
ctx->force = true;
}
name++;
/* split the cell name out if there is one */
ctx->volname = strchr(name, ':');
if (ctx->volname) {
cellname = name;
cellnamesz = ctx->volname - name;
ctx->volname++;
} else {
ctx->volname = name;
cellname = NULL;
cellnamesz = 0;
}
/* the volume type is further affected by a possible suffix */
suffix = strrchr(ctx->volname, '.');
if (suffix) {
if (strcmp(suffix, ".readonly") == 0) {
ctx->type = AFSVL_ROVOL;
ctx->force = true;
} else if (strcmp(suffix, ".backup") == 0) {
ctx->type = AFSVL_BACKVOL;
ctx->force = true;
} else if (suffix[1] == 0) {
} else {
suffix = NULL;
}
}
ctx->volnamesz = suffix ?
suffix - ctx->volname : strlen(ctx->volname);
_debug("cell %*.*s [%p]",
cellnamesz, cellnamesz, cellname ?: "", ctx->cell);
/* lookup the cell record */
if (cellname) {
cell = afs_lookup_cell(ctx->net, cellname, cellnamesz,
NULL, false);
if (IS_ERR(cell)) {
pr_err("kAFS: unable to lookup cell '%*.*s'\n",
cellnamesz, cellnamesz, cellname ?: "");
return PTR_ERR(cell);
}
afs_put_cell(ctx->net, ctx->cell);
ctx->cell = cell;
}
_debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
ctx->cell->name, ctx->cell,
ctx->volnamesz, ctx->volnamesz, ctx->volname,
suffix ?: "-", ctx->type, ctx->force ? " FORCE" : "");
fc->source = param->string;
param->string = NULL;
return 0;
}
/*
* Parse a single mount parameter.
*/
static int afs_parse_param(struct fs_context *fc, struct fs_parameter *param)
{
struct fs_parse_result result;
struct afs_fs_context *ctx = fc->fs_private;
int opt;
opt = fs_parse(fc, afs_fs_parameters, param, &result);
if (opt < 0)
return opt;
switch (opt) {
case Opt_source:
return afs_parse_source(fc, param);
case Opt_autocell:
ctx->autocell = true;
break;
case Opt_dyn:
ctx->dyn_root = true;
break;
case Opt_flock:
ctx->flock_mode = result.uint_32;
break;
default:
return -EINVAL;
}
_leave(" = 0");
return 0;
}
/*
* Validate the options, get the cell key and look up the volume.
*/
static int afs_validate_fc(struct fs_context *fc)
{
struct afs_fs_context *ctx = fc->fs_private;
struct afs_volume *volume;
struct key *key;
if (!ctx->dyn_root) {
if (ctx->no_cell) {
pr_warn("kAFS: Can only specify source 'none' with -o dyn\n");
return -EINVAL;
}
if (!ctx->cell) {
pr_warn("kAFS: No cell specified\n");
return -EDESTADDRREQ;
}
/* We try to do the mount securely. */
key = afs_request_key(ctx->cell);
if (IS_ERR(key))
return PTR_ERR(key);
ctx->key = key;
if (ctx->volume) {
afs_put_volume(ctx->cell, ctx->volume);
ctx->volume = NULL;
}
volume = afs_create_volume(ctx);
if (IS_ERR(volume))
return PTR_ERR(volume);
ctx->volume = volume;
}
return 0;
}
/*
* check a superblock to see if it's the one we're looking for
*/
static int afs_test_super(struct super_block *sb, struct fs_context *fc)
{
struct afs_fs_context *ctx = fc->fs_private;
struct afs_super_info *as = AFS_FS_S(sb);
return (as->net_ns == fc->net_ns &&
as->volume &&
as->volume->vid == ctx->volume->vid &&
as->cell == ctx->cell &&
!as->dyn_root);
}
static int afs_dynroot_test_super(struct super_block *sb, struct fs_context *fc)
{
struct afs_super_info *as = AFS_FS_S(sb);
return (as->net_ns == fc->net_ns &&
as->dyn_root);
}
static int afs_set_super(struct super_block *sb, struct fs_context *fc)
{
return set_anon_super(sb, NULL);
}
/*
* fill in the superblock
*/
static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
{
struct afs_super_info *as = AFS_FS_S(sb);
struct afs_iget_data iget_data;
struct inode *inode = NULL;
int ret;
_enter("");
/* fill in the superblock */
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_magic = AFS_FS_MAGIC;
sb->s_op = &afs_super_ops;
if (!as->dyn_root)
sb->s_xattr = afs_xattr_handlers;
ret = super_setup_bdi(sb);
if (ret)
return ret;
sb->s_bdi->ra_pages = VM_READAHEAD_PAGES;
/* allocate the root inode and dentry */
if (as->dyn_root) {
inode = afs_iget_pseudo_dir(sb, true);
} else {
sprintf(sb->s_id, "%llu", as->volume->vid);
afs_activate_volume(as->volume);
iget_data.fid.vid = as->volume->vid;
iget_data.fid.vnode = 1;
iget_data.fid.vnode_hi = 0;
iget_data.fid.unique = 1;
iget_data.cb_v_break = as->volume->cb_v_break;
iget_data.cb_s_break = 0;
inode = afs_iget(sb, ctx->key, &iget_data, NULL, NULL, NULL);
}
if (IS_ERR(inode))
return PTR_ERR(inode);
if (ctx->autocell || as->dyn_root)
set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
ret = -ENOMEM;
sb->s_root = d_make_root(inode);
if (!sb->s_root)
goto error;
if (as->dyn_root) {
sb->s_d_op = &afs_dynroot_dentry_operations;
ret = afs_dynroot_populate(sb);
if (ret < 0)
goto error;
} else {
sb->s_d_op = &afs_fs_dentry_operations;
}
_leave(" = 0");
return 0;
error:
_leave(" = %d", ret);
return ret;
}
static struct afs_super_info *afs_alloc_sbi(struct fs_context *fc)
{
struct afs_fs_context *ctx = fc->fs_private;
struct afs_super_info *as;
as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
if (as) {
as->net_ns = get_net(fc->net_ns);
as->flock_mode = ctx->flock_mode;
if (ctx->dyn_root) {
as->dyn_root = true;
} else {
as->cell = afs_get_cell(ctx->cell);
as->volume = __afs_get_volume(ctx->volume);
}
}
return as;
}
static void afs_destroy_sbi(struct afs_super_info *as)
{
if (as) {
afs_put_volume(as->cell, as->volume);
afs_put_cell(afs_net(as->net_ns), as->cell);
put_net(as->net_ns);
kfree(as);
}
}
static void afs_kill_super(struct super_block *sb)
{
struct afs_super_info *as = AFS_FS_S(sb);
struct afs_net *net = afs_net(as->net_ns);
if (as->dyn_root)
afs_dynroot_depopulate(sb);
/* Clear the callback interests (which will do ilookup5) before
* deactivating the superblock.
*/
if (as->volume)
afs_clear_callback_interests(net, as->volume->servers);
kill_anon_super(sb);
if (as->volume)
afs_deactivate_volume(as->volume);
afs_destroy_sbi(as);
}
/*
* Get an AFS superblock and root directory.
*/
static int afs_get_tree(struct fs_context *fc)
{
struct afs_fs_context *ctx = fc->fs_private;
struct super_block *sb;
struct afs_super_info *as;
int ret;
ret = afs_validate_fc(fc);
if (ret)
goto error;
_enter("");
/* allocate a superblock info record */
ret = -ENOMEM;
as = afs_alloc_sbi(fc);
if (!as)
goto error;
fc->s_fs_info = as;
/* allocate a deviceless superblock */
sb = sget_fc(fc,
as->dyn_root ? afs_dynroot_test_super : afs_test_super,
afs_set_super);
if (IS_ERR(sb)) {
ret = PTR_ERR(sb);
goto error;
}
if (!sb->s_root) {
/* initial superblock/root creation */
_debug("create");
ret = afs_fill_super(sb, ctx);
if (ret < 0)
goto error_sb;
sb->s_flags |= SB_ACTIVE;
} else {
_debug("reuse");
ASSERTCMP(sb->s_flags, &, SB_ACTIVE);
}
fc->root = dget(sb->s_root);
trace_afs_get_tree(as->cell, as->volume);
_leave(" = 0 [%p]", sb);
return 0;
error_sb:
deactivate_locked_super(sb);
error:
_leave(" = %d", ret);
return ret;
}
static void afs_free_fc(struct fs_context *fc)
{
struct afs_fs_context *ctx = fc->fs_private;
afs_destroy_sbi(fc->s_fs_info);
afs_put_volume(ctx->cell, ctx->volume);
afs_put_cell(ctx->net, ctx->cell);
key_put(ctx->key);
kfree(ctx);
}
static const struct fs_context_operations afs_context_ops = {
.free = afs_free_fc,
.parse_param = afs_parse_param,
.get_tree = afs_get_tree,
};
/*
* Set up the filesystem mount context.
*/
static int afs_init_fs_context(struct fs_context *fc)
{
struct afs_fs_context *ctx;
struct afs_cell *cell;
ctx = kzalloc(sizeof(struct afs_fs_context), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
ctx->type = AFSVL_ROVOL;
ctx->net = afs_net(fc->net_ns);
/* Default to the workstation cell. */
rcu_read_lock();
cell = afs_lookup_cell_rcu(ctx->net, NULL, 0);
rcu_read_unlock();
if (IS_ERR(cell))
cell = NULL;
ctx->cell = cell;
fc->fs_private = ctx;
fc->ops = &afs_context_ops;
return 0;
}
/*
* Initialise an inode cache slab element prior to any use. Note that
* afs_alloc_inode() *must* reset anything that could incorrectly leak from one
* inode to another.
*/
static void afs_i_init_once(void *_vnode)
{
struct afs_vnode *vnode = _vnode;
memset(vnode, 0, sizeof(*vnode));
inode_init_once(&vnode->vfs_inode);
mutex_init(&vnode->io_lock);
init_rwsem(&vnode->validate_lock);
spin_lock_init(&vnode->wb_lock);
spin_lock_init(&vnode->lock);
INIT_LIST_HEAD(&vnode->wb_keys);
INIT_LIST_HEAD(&vnode->pending_locks);
INIT_LIST_HEAD(&vnode->granted_locks);
INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
seqlock_init(&vnode->cb_lock);
}
/*
* allocate an AFS inode struct from our slab cache
*/
static struct inode *afs_alloc_inode(struct super_block *sb)
{
struct afs_vnode *vnode;
vnode = kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL);
if (!vnode)
return NULL;
atomic_inc(&afs_count_active_inodes);
/* Reset anything that shouldn't leak from one inode to the next. */
memset(&vnode->fid, 0, sizeof(vnode->fid));
memset(&vnode->status, 0, sizeof(vnode->status));
vnode->volume = NULL;
vnode->lock_key = NULL;
vnode->permit_cache = NULL;
RCU_INIT_POINTER(vnode->cb_interest, NULL);
#ifdef CONFIG_AFS_FSCACHE
vnode->cache = NULL;
#endif
vnode->flags = 1 << AFS_VNODE_UNSET;
vnode->lock_state = AFS_VNODE_LOCK_NONE;
init_rwsem(&vnode->rmdir_lock);
_leave(" = %p", &vnode->vfs_inode);
return &vnode->vfs_inode;
}
static void afs_free_inode(struct inode *inode)
{
kmem_cache_free(afs_inode_cachep, AFS_FS_I(inode));
}
/*
* destroy an AFS inode struct
*/
static void afs_destroy_inode(struct inode *inode)
{
struct afs_vnode *vnode = AFS_FS_I(inode);
_enter("%p{%llx:%llu}", inode, vnode->fid.vid, vnode->fid.vnode);
_debug("DESTROY INODE %p", inode);
ASSERTCMP(rcu_access_pointer(vnode->cb_interest), ==, NULL);
atomic_dec(&afs_count_active_inodes);
}
/*
* return information about an AFS volume
*/
static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct afs_super_info *as = AFS_FS_S(dentry->d_sb);
struct afs_fs_cursor fc;
struct afs_volume_status vs;
struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
struct key *key;
int ret;
buf->f_type = dentry->d_sb->s_magic;
buf->f_bsize = AFS_BLOCK_SIZE;
buf->f_namelen = AFSNAMEMAX - 1;
if (as->dyn_root) {
buf->f_blocks = 1;
buf->f_bavail = 0;
buf->f_bfree = 0;
return 0;
}
key = afs_request_key(vnode->volume->cell);
if (IS_ERR(key))
return PTR_ERR(key);
ret = -ERESTARTSYS;
if (afs_begin_vnode_operation(&fc, vnode, key, true)) {
fc.flags |= AFS_FS_CURSOR_NO_VSLEEP;
while (afs_select_fileserver(&fc)) {
fc.cb_break = afs_calc_vnode_cb_break(vnode);
afs_fs_get_volume_status(&fc, &vs);
}
afs_check_for_remote_deletion(&fc, fc.vnode);
ret = afs_end_vnode_operation(&fc);
}
key_put(key);
if (ret == 0) {
if (vs.max_quota == 0)
buf->f_blocks = vs.part_max_blocks;
else
buf->f_blocks = vs.max_quota;
buf->f_bavail = buf->f_bfree = buf->f_blocks - vs.blocks_in_use;
}
return ret;
}
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