blob: 8d969fd4af4034e3f5dc7f5f7b310e08238e2b19 [file] [log] [blame]
/* 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 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, struct dentry *reference);
static const struct fs_parameter_description 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 = 0,
};
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,
.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_cell,
Opt_dyn,
Opt_rwpath,
Opt_source,
Opt_vol,
nr__afs_params
};
static const struct fs_parameter_spec afs_param_specs[nr__afs_params] = {
[Opt_autocell] = { fs_param_is_flag },
[Opt_cell] = { fs_param_is_string },
[Opt_dyn] = { fs_param_is_flag },
[Opt_rwpath] = { fs_param_is_flag },
[Opt_source] = { fs_param_is_string },
[Opt_vol] = { fs_param_is_string },
};
static const char *const afs_param_keys[nr__afs_params] = {
[Opt_autocell] = "autocell",
[Opt_cell] = "cell",
[Opt_dyn] = "dyn",
[Opt_rwpath] = "rwpath",
[Opt_source] = "source",
[Opt_vol] = "vol",
};
static const struct fs_parameter_description afs_fs_parameters = {
.name = "kAFS",
.nr_params = nr__afs_params,
.source_param = Opt_source,
.keys = afs_param_keys,
.specs = afs_param_specs,
};
/*
* 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);
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");
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 (rwpath=0),
* or R/W (rwpath=1) 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 */
ctx->type = AFSVL_ROVOL;
ctx->force = false;
if (ctx->rwpath || 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;
struct afs_cell *cell;
int opt;
opt = fs_parse(fc, &afs_fs_parameters, param, &result);
if (opt < 0)
return opt;
switch (opt) {
case Opt_cell:
if (param->size <= 0)
return -EINVAL;
if (param->size > AFS_MAXCELLNAME)
return -ENAMETOOLONG;
rcu_read_lock();
cell = afs_lookup_cell_rcu(ctx->net, param->string, param->size);
rcu_read_unlock();
if (IS_ERR(cell))
return PTR_ERR(cell);
afs_put_cell(ctx->net, ctx->cell);
ctx->cell = cell;
break;
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_rwpath:
ctx->rwpath = true;
break;
case Opt_vol:
return invalf(fc, "'vol' param is obsolete");
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->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_fid fid;
struct inode *inode = NULL;
int ret;
_enter("");
/* fill in the superblock */
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
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_MAX_READAHEAD * 1024 / PAGE_SIZE;
/* allocate the root inode and dentry */
if (as->dyn_root) {
inode = afs_iget_pseudo_dir(sb, true);
sb->s_flags |= SB_RDONLY;
} else {
sprintf(sb->s_id, "%u", as->volume->vid);
afs_activate_volume(as->volume);
fid.vid = as->volume->vid;
fid.vnode = 1;
fid.unique = 1;
inode = afs_iget(sb, ctx->key, &fid, 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);
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;
_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);
_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,
.validate = afs_validate_fc,
.get_tree = afs_get_tree,
};
/*
* Set up the filesystem mount context.
*/
static int afs_init_fs_context(struct fs_context *fc, struct dentry *reference)
{
struct afs_fs_context *ctx;
struct afs_super_info *src_as;
struct afs_cell *cell;
if (current->nsproxy->net_ns != &init_net)
return -EINVAL;
ctx = kzalloc(sizeof(struct afs_fs_context), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
ctx->type = AFSVL_ROVOL;
switch (fc->purpose) {
case FS_CONTEXT_FOR_USER_MOUNT:
case FS_CONTEXT_FOR_KERNEL_MOUNT:
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;
break;
case FS_CONTEXT_FOR_SUBMOUNT:
if (!reference) {
kfree(ctx);
return -EINVAL;
}
src_as = AFS_FS_S(reference->d_sb);
ASSERT(src_as);
ctx->net = afs_net(fc->net_ns);
if (src_as->cell)
ctx->cell = afs_get_cell(src_as->cell);
if (src_as->volume && src_as->volume->type == AFSVL_RWVOL) {
ctx->type = AFSVL_RWVOL;
ctx->force = true;
}
break;
default:
break;
}
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;
vnode->cb_interest = NULL;
#ifdef CONFIG_AFS_FSCACHE
vnode->cache = NULL;
#endif
vnode->flags = 1 << AFS_VNODE_UNSET;
vnode->cb_type = 0;
vnode->lock_state = AFS_VNODE_LOCK_NONE;
_leave(" = %p", &vnode->vfs_inode);
return &vnode->vfs_inode;
}
static void afs_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
struct afs_vnode *vnode = AFS_FS_I(inode);
kmem_cache_free(afs_inode_cachep, vnode);
}
/*
* destroy an AFS inode struct
*/
static void afs_destroy_inode(struct inode *inode)
{
struct afs_vnode *vnode = AFS_FS_I(inode);
_enter("%p{%x:%u}", inode, vnode->fid.vid, vnode->fid.vnode);
_debug("DESTROY INODE %p", inode);
ASSERTCMP(vnode->cb_interest, ==, NULL);
call_rcu(&inode->i_rcu, afs_i_callback);
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)) {
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);
afs_vnode_commit_status(&fc, vnode, fc.cb_break);
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;
}