linux/fs/hfsplus/super.c

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/*
* linux/fs/hfsplus/super.c
*
* Copyright (C) 2001
* Brad Boyer (flar@allandria.com)
* (C) 2003 Ardis Technologies <roman@ardistech.com>
*
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/blkdev.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/vfs.h>
#include <linux/nls.h>
static struct inode *hfsplus_alloc_inode(struct super_block *sb);
static void hfsplus_destroy_inode(struct inode *inode);
#include "hfsplus_fs.h"
#include "xattr.h"
static int hfsplus_system_read_inode(struct inode *inode)
{
struct hfsplus_vh *vhdr = HFSPLUS_SB(inode->i_sb)->s_vhdr;
switch (inode->i_ino) {
case HFSPLUS_EXT_CNID:
hfsplus_inode_read_fork(inode, &vhdr->ext_file);
inode->i_mapping->a_ops = &hfsplus_btree_aops;
break;
case HFSPLUS_CAT_CNID:
hfsplus_inode_read_fork(inode, &vhdr->cat_file);
inode->i_mapping->a_ops = &hfsplus_btree_aops;
break;
case HFSPLUS_ALLOC_CNID:
hfsplus_inode_read_fork(inode, &vhdr->alloc_file);
inode->i_mapping->a_ops = &hfsplus_aops;
break;
case HFSPLUS_START_CNID:
hfsplus_inode_read_fork(inode, &vhdr->start_file);
break;
case HFSPLUS_ATTR_CNID:
hfsplus_inode_read_fork(inode, &vhdr->attr_file);
inode->i_mapping->a_ops = &hfsplus_btree_aops;
break;
default:
return -EIO;
}
return 0;
}
struct inode *hfsplus_iget(struct super_block *sb, unsigned long ino)
{
struct hfs_find_data fd;
struct inode *inode;
int err;
inode = iget_locked(sb, ino);
if (!inode)
return ERR_PTR(-ENOMEM);
if (!(inode->i_state & I_NEW))
return inode;
INIT_LIST_HEAD(&HFSPLUS_I(inode)->open_dir_list);
mutex_init(&HFSPLUS_I(inode)->extents_lock);
HFSPLUS_I(inode)->flags = 0;
HFSPLUS_I(inode)->extent_state = 0;
HFSPLUS_I(inode)->rsrc_inode = NULL;
atomic_set(&HFSPLUS_I(inode)->opencnt, 0);
if (inode->i_ino >= HFSPLUS_FIRSTUSER_CNID ||
inode->i_ino == HFSPLUS_ROOT_CNID) {
err = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
if (!err) {
err = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
if (!err)
err = hfsplus_cat_read_inode(inode, &fd);
hfs_find_exit(&fd);
}
} else {
err = hfsplus_system_read_inode(inode);
}
if (err) {
iget_failed(inode);
return ERR_PTR(err);
}
unlock_new_inode(inode);
return inode;
}
static int hfsplus_system_write_inode(struct inode *inode)
{
struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
struct hfsplus_vh *vhdr = sbi->s_vhdr;
struct hfsplus_fork_raw *fork;
struct hfs_btree *tree = NULL;
switch (inode->i_ino) {
case HFSPLUS_EXT_CNID:
fork = &vhdr->ext_file;
tree = sbi->ext_tree;
break;
case HFSPLUS_CAT_CNID:
fork = &vhdr->cat_file;
tree = sbi->cat_tree;
break;
case HFSPLUS_ALLOC_CNID:
fork = &vhdr->alloc_file;
break;
case HFSPLUS_START_CNID:
fork = &vhdr->start_file;
break;
case HFSPLUS_ATTR_CNID:
fork = &vhdr->attr_file;
tree = sbi->attr_tree;
break;
default:
return -EIO;
}
if (fork->total_size != cpu_to_be64(inode->i_size)) {
set_bit(HFSPLUS_SB_WRITEBACKUP, &sbi->flags);
hfsplus_mark_mdb_dirty(inode->i_sb);
}
hfsplus_inode_write_fork(inode, fork);
if (tree) {
int err = hfs_btree_write(tree);
if (err) {
printk(KERN_ERR "hfs: b-tree write err: %d, ino %lu\n",
err, inode->i_ino);
return err;
}
}
return 0;
}
static int hfsplus_write_inode(struct inode *inode,
struct writeback_control *wbc)
{
int err;
dprint(DBG_INODE, "hfsplus_write_inode: %lu\n", inode->i_ino);
err = hfsplus_ext_write_extent(inode);
if (err)
return err;
if (inode->i_ino >= HFSPLUS_FIRSTUSER_CNID ||
inode->i_ino == HFSPLUS_ROOT_CNID)
return hfsplus_cat_write_inode(inode);
else
return hfsplus_system_write_inode(inode);
}
static void hfsplus_evict_inode(struct inode *inode)
{
dprint(DBG_INODE, "hfsplus_evict_inode: %lu\n", inode->i_ino);
truncate_inode_pages(&inode->i_data, 0);
clear_inode(inode);
if (HFSPLUS_IS_RSRC(inode)) {
HFSPLUS_I(HFSPLUS_I(inode)->rsrc_inode)->rsrc_inode = NULL;
iput(HFSPLUS_I(inode)->rsrc_inode);
}
}
static int hfsplus_sync_fs(struct super_block *sb, int wait)
{
struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
struct hfsplus_vh *vhdr = sbi->s_vhdr;
int write_backup = 0;
int error, error2;
if (!wait)
return 0;
dprint(DBG_SUPER, "hfsplus_sync_fs\n");
/*
* Explicitly write out the special metadata inodes.
*
* While these special inodes are marked as hashed and written
* out peridocically by the flusher threads we redirty them
* during writeout of normal inodes, and thus the life lock
* prevents us from getting the latest state to disk.
*/
error = filemap_write_and_wait(sbi->cat_tree->inode->i_mapping);
error2 = filemap_write_and_wait(sbi->ext_tree->inode->i_mapping);
if (!error)
error = error2;
if (sbi->attr_tree) {
error2 =
filemap_write_and_wait(sbi->attr_tree->inode->i_mapping);
if (!error)
error = error2;
}
error2 = filemap_write_and_wait(sbi->alloc_file->i_mapping);
if (!error)
error = error2;
mutex_lock(&sbi->vh_mutex);
mutex_lock(&sbi->alloc_mutex);
vhdr->free_blocks = cpu_to_be32(sbi->free_blocks);
vhdr->next_cnid = cpu_to_be32(sbi->next_cnid);
vhdr->folder_count = cpu_to_be32(sbi->folder_count);
vhdr->file_count = cpu_to_be32(sbi->file_count);
if (test_and_clear_bit(HFSPLUS_SB_WRITEBACKUP, &sbi->flags)) {
memcpy(sbi->s_backup_vhdr, sbi->s_vhdr, sizeof(*sbi->s_vhdr));
write_backup = 1;
}
error2 = hfsplus_submit_bio(sb,
sbi->part_start + HFSPLUS_VOLHEAD_SECTOR,
sbi->s_vhdr_buf, NULL, WRITE_SYNC);
if (!error)
error = error2;
if (!write_backup)
goto out;
error2 = hfsplus_submit_bio(sb,
sbi->part_start + sbi->sect_count - 2,
sbi->s_backup_vhdr_buf, NULL, WRITE_SYNC);
if (!error)
error2 = error;
out:
mutex_unlock(&sbi->alloc_mutex);
mutex_unlock(&sbi->vh_mutex);
if (!test_bit(HFSPLUS_SB_NOBARRIER, &sbi->flags))
blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
return error;
}
static void delayed_sync_fs(struct work_struct *work)
{
int err;
struct hfsplus_sb_info *sbi;
sbi = container_of(work, struct hfsplus_sb_info, sync_work.work);
spin_lock(&sbi->work_lock);
sbi->work_queued = 0;
spin_unlock(&sbi->work_lock);
err = hfsplus_sync_fs(sbi->alloc_file->i_sb, 1);
if (err)
printk(KERN_ERR "hfs: delayed sync fs err %d\n", err);
}
void hfsplus_mark_mdb_dirty(struct super_block *sb)
{
struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
unsigned long delay;
if (sb->s_flags & MS_RDONLY)
return;
spin_lock(&sbi->work_lock);
if (!sbi->work_queued) {
delay = msecs_to_jiffies(dirty_writeback_interval * 10);
queue_delayed_work(system_long_wq, &sbi->sync_work, delay);
sbi->work_queued = 1;
}
spin_unlock(&sbi->work_lock);
}
static void hfsplus_put_super(struct super_block *sb)
{
struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
dprint(DBG_SUPER, "hfsplus_put_super\n");
cancel_delayed_work_sync(&sbi->sync_work);
if (!(sb->s_flags & MS_RDONLY) && sbi->s_vhdr) {
struct hfsplus_vh *vhdr = sbi->s_vhdr;
vhdr->modify_date = hfsp_now2mt();
vhdr->attributes |= cpu_to_be32(HFSPLUS_VOL_UNMNT);
vhdr->attributes &= cpu_to_be32(~HFSPLUS_VOL_INCNSTNT);
hfsplus_sync_fs(sb, 1);
}
hfs_btree_close(sbi->attr_tree);
hfs_btree_close(sbi->cat_tree);
hfs_btree_close(sbi->ext_tree);
iput(sbi->alloc_file);
iput(sbi->hidden_dir);
kfree(sbi->s_vhdr_buf);
kfree(sbi->s_backup_vhdr_buf);
unload_nls(sbi->nls);
kfree(sb->s_fs_info);
sb->s_fs_info = NULL;
}
static int hfsplus_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
buf->f_type = HFSPLUS_SUPER_MAGIC;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = sbi->total_blocks << sbi->fs_shift;
buf->f_bfree = sbi->free_blocks << sbi->fs_shift;
buf->f_bavail = buf->f_bfree;
buf->f_files = 0xFFFFFFFF;
buf->f_ffree = 0xFFFFFFFF - sbi->next_cnid;
buf->f_fsid.val[0] = (u32)id;
buf->f_fsid.val[1] = (u32)(id >> 32);
buf->f_namelen = HFSPLUS_MAX_STRLEN;
return 0;
}
static int hfsplus_remount(struct super_block *sb, int *flags, char *data)
{
if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
return 0;
if (!(*flags & MS_RDONLY)) {
struct hfsplus_vh *vhdr = HFSPLUS_SB(sb)->s_vhdr;
int force = 0;
if (!hfsplus_parse_options_remount(data, &force))
return -EINVAL;
if (!(vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_UNMNT))) {
printk(KERN_WARNING "hfs: filesystem was "
"not cleanly unmounted, "
"running fsck.hfsplus is recommended. "
"leaving read-only.\n");
sb->s_flags |= MS_RDONLY;
*flags |= MS_RDONLY;
} else if (force) {
/* nothing */
} else if (vhdr->attributes &
cpu_to_be32(HFSPLUS_VOL_SOFTLOCK)) {
printk(KERN_WARNING "hfs: filesystem is marked locked, "
"leaving read-only.\n");
sb->s_flags |= MS_RDONLY;
*flags |= MS_RDONLY;
} else if (vhdr->attributes &
cpu_to_be32(HFSPLUS_VOL_JOURNALED)) {
printk(KERN_WARNING "hfs: filesystem is "
"marked journaled, "
"leaving read-only.\n");
sb->s_flags |= MS_RDONLY;
*flags |= MS_RDONLY;
}
}
return 0;
}
static const struct super_operations hfsplus_sops = {
.alloc_inode = hfsplus_alloc_inode,
.destroy_inode = hfsplus_destroy_inode,
.write_inode = hfsplus_write_inode,
.evict_inode = hfsplus_evict_inode,
.put_super = hfsplus_put_super,
.sync_fs = hfsplus_sync_fs,
.statfs = hfsplus_statfs,
.remount_fs = hfsplus_remount,
.show_options = hfsplus_show_options,
};
static int hfsplus_fill_super(struct super_block *sb, void *data, int silent)
{
struct hfsplus_vh *vhdr;
struct hfsplus_sb_info *sbi;
hfsplus_cat_entry entry;
struct hfs_find_data fd;
struct inode *root, *inode;
struct qstr str;
struct nls_table *nls = NULL;
u64 last_fs_block, last_fs_page;
int err;
err = -ENOMEM;
sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
if (!sbi)
goto out;
sb->s_fs_info = sbi;
mutex_init(&sbi->alloc_mutex);
mutex_init(&sbi->vh_mutex);
spin_lock_init(&sbi->work_lock);
INIT_DELAYED_WORK(&sbi->sync_work, delayed_sync_fs);
hfsplus_fill_defaults(sbi);
err = -EINVAL;
if (!hfsplus_parse_options(data, sbi)) {
printk(KERN_ERR "hfs: unable to parse mount options\n");
goto out_unload_nls;
}
/* temporarily use utf8 to correctly find the hidden dir below */
nls = sbi->nls;
sbi->nls = load_nls("utf8");
if (!sbi->nls) {
printk(KERN_ERR "hfs: unable to load nls for utf8\n");
goto out_unload_nls;
}
/* Grab the volume header */
if (hfsplus_read_wrapper(sb)) {
if (!silent)
printk(KERN_WARNING "hfs: unable to find HFS+ superblock\n");
goto out_unload_nls;
}
vhdr = sbi->s_vhdr;
/* Copy parts of the volume header into the superblock */
sb->s_magic = HFSPLUS_VOLHEAD_SIG;
if (be16_to_cpu(vhdr->version) < HFSPLUS_MIN_VERSION ||
be16_to_cpu(vhdr->version) > HFSPLUS_CURRENT_VERSION) {
printk(KERN_ERR "hfs: wrong filesystem version\n");
goto out_free_vhdr;
}
sbi->total_blocks = be32_to_cpu(vhdr->total_blocks);
sbi->free_blocks = be32_to_cpu(vhdr->free_blocks);
sbi->next_cnid = be32_to_cpu(vhdr->next_cnid);
sbi->file_count = be32_to_cpu(vhdr->file_count);
sbi->folder_count = be32_to_cpu(vhdr->folder_count);
sbi->data_clump_blocks =
be32_to_cpu(vhdr->data_clump_sz) >> sbi->alloc_blksz_shift;
if (!sbi->data_clump_blocks)
sbi->data_clump_blocks = 1;
sbi->rsrc_clump_blocks =
be32_to_cpu(vhdr->rsrc_clump_sz) >> sbi->alloc_blksz_shift;
if (!sbi->rsrc_clump_blocks)
sbi->rsrc_clump_blocks = 1;
err = -EFBIG;
last_fs_block = sbi->total_blocks - 1;
last_fs_page = (last_fs_block << sbi->alloc_blksz_shift) >>
PAGE_CACHE_SHIFT;
if ((last_fs_block > (sector_t)(~0ULL) >> (sbi->alloc_blksz_shift - 9)) ||
(last_fs_page > (pgoff_t)(~0ULL))) {
printk(KERN_ERR "hfs: filesystem size too large.\n");
goto out_free_vhdr;
}
/* Set up operations so we can load metadata */
sb->s_op = &hfsplus_sops;
sb->s_maxbytes = MAX_LFS_FILESIZE;
if (!(vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_UNMNT))) {
printk(KERN_WARNING "hfs: Filesystem was "
"not cleanly unmounted, "
"running fsck.hfsplus is recommended. "
"mounting read-only.\n");
sb->s_flags |= MS_RDONLY;
} else if (test_and_clear_bit(HFSPLUS_SB_FORCE, &sbi->flags)) {
/* nothing */
} else if (vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_SOFTLOCK)) {
printk(KERN_WARNING "hfs: Filesystem is marked locked, mounting read-only.\n");
sb->s_flags |= MS_RDONLY;
} else if ((vhdr->attributes & cpu_to_be32(HFSPLUS_VOL_JOURNALED)) &&
!(sb->s_flags & MS_RDONLY)) {
printk(KERN_WARNING "hfs: write access to "
"a journaled filesystem is not supported, "
"use the force option at your own risk, "
"mounting read-only.\n");
sb->s_flags |= MS_RDONLY;
}
err = -EINVAL;
/* Load metadata objects (B*Trees) */
sbi->ext_tree = hfs_btree_open(sb, HFSPLUS_EXT_CNID);
if (!sbi->ext_tree) {
printk(KERN_ERR "hfs: failed to load extents file\n");
goto out_free_vhdr;
}
sbi->cat_tree = hfs_btree_open(sb, HFSPLUS_CAT_CNID);
if (!sbi->cat_tree) {
printk(KERN_ERR "hfs: failed to load catalog file\n");
goto out_close_ext_tree;
}
if (vhdr->attr_file.total_blocks != 0) {
sbi->attr_tree = hfs_btree_open(sb, HFSPLUS_ATTR_CNID);
if (!sbi->attr_tree) {
printk(KERN_ERR "hfs: failed to load attributes file\n");
goto out_close_cat_tree;
}
}
sb->s_xattr = hfsplus_xattr_handlers;
inode = hfsplus_iget(sb, HFSPLUS_ALLOC_CNID);
if (IS_ERR(inode)) {
printk(KERN_ERR "hfs: failed to load allocation file\n");
err = PTR_ERR(inode);
goto out_close_attr_tree;
}
sbi->alloc_file = inode;
/* Load the root directory */
root = hfsplus_iget(sb, HFSPLUS_ROOT_CNID);
if (IS_ERR(root)) {
printk(KERN_ERR "hfs: failed to load root directory\n");
err = PTR_ERR(root);
goto out_put_alloc_file;
}
sb->s_d_op = &hfsplus_dentry_operations;
sb->s_root = d_make_root(root);
if (!sb->s_root) {
err = -ENOMEM;
goto out_put_alloc_file;
}
str.len = sizeof(HFSP_HIDDENDIR_NAME) - 1;
str.name = HFSP_HIDDENDIR_NAME;
err = hfs_find_init(sbi->cat_tree, &fd);
if (err)
goto out_put_root;
hfsplus_cat_build_key(sb, fd.search_key, HFSPLUS_ROOT_CNID, &str);
if (!hfs_brec_read(&fd, &entry, sizeof(entry))) {
hfs_find_exit(&fd);
if (entry.type != cpu_to_be16(HFSPLUS_FOLDER))
goto out_put_root;
inode = hfsplus_iget(sb, be32_to_cpu(entry.folder.id));
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_put_root;
}
sbi->hidden_dir = inode;
} else
hfs_find_exit(&fd);
if (!(sb->s_flags & MS_RDONLY)) {
/*
* H+LX == hfsplusutils, H+Lx == this driver, H+lx is unused
* all three are registered with Apple for our use
*/
vhdr->last_mount_vers = cpu_to_be32(HFSP_MOUNT_VERSION);
vhdr->modify_date = hfsp_now2mt();
be32_add_cpu(&vhdr->write_count, 1);
vhdr->attributes &= cpu_to_be32(~HFSPLUS_VOL_UNMNT);
vhdr->attributes |= cpu_to_be32(HFSPLUS_VOL_INCNSTNT);
hfsplus_sync_fs(sb, 1);
if (!sbi->hidden_dir) {
mutex_lock(&sbi->vh_mutex);
sbi->hidden_dir = hfsplus_new_inode(sb, S_IFDIR);
if (!sbi->hidden_dir) {
mutex_unlock(&sbi->vh_mutex);
err = -ENOMEM;
goto out_put_root;
}
err = hfsplus_create_cat(sbi->hidden_dir->i_ino, root,
&str, sbi->hidden_dir);
if (err) {
mutex_unlock(&sbi->vh_mutex);
goto out_put_hidden_dir;
}
err = hfsplus_init_inode_security(sbi->hidden_dir,
root, &str);
if (err == -EOPNOTSUPP)
err = 0; /* Operation is not supported. */
else if (err) {
/*
* Try to delete anyway without
* error analysis.
*/
hfsplus_delete_cat(sbi->hidden_dir->i_ino,
root, &str);
mutex_unlock(&sbi->vh_mutex);
goto out_put_hidden_dir;
}
mutex_unlock(&sbi->vh_mutex);
hfsplus_mark_inode_dirty(sbi->hidden_dir,
HFSPLUS_I_CAT_DIRTY);
}
}
unload_nls(sbi->nls);
sbi->nls = nls;
return 0;
out_put_hidden_dir:
iput(sbi->hidden_dir);
out_put_root:
dput(sb->s_root);
sb->s_root = NULL;
out_put_alloc_file:
iput(sbi->alloc_file);
out_close_attr_tree:
hfs_btree_close(sbi->attr_tree);
out_close_cat_tree:
hfs_btree_close(sbi->cat_tree);
out_close_ext_tree:
hfs_btree_close(sbi->ext_tree);
out_free_vhdr:
kfree(sbi->s_vhdr_buf);
kfree(sbi->s_backup_vhdr_buf);
out_unload_nls:
unload_nls(sbi->nls);
unload_nls(nls);
kfree(sbi);
out:
return err;
}
MODULE_AUTHOR("Brad Boyer");
MODULE_DESCRIPTION("Extended Macintosh Filesystem");
MODULE_LICENSE("GPL");
static struct kmem_cache *hfsplus_inode_cachep;
static struct inode *hfsplus_alloc_inode(struct super_block *sb)
{
struct hfsplus_inode_info *i;
i = kmem_cache_alloc(hfsplus_inode_cachep, GFP_KERNEL);
return i ? &i->vfs_inode : NULL;
}
2011-01-07 06:49:49 +00:00
static void hfsplus_i_callback(struct rcu_head *head)
{
2011-01-07 06:49:49 +00:00
struct inode *inode = container_of(head, struct inode, i_rcu);
kmem_cache_free(hfsplus_inode_cachep, HFSPLUS_I(inode));
}
2011-01-07 06:49:49 +00:00
static void hfsplus_destroy_inode(struct inode *inode)
{
call_rcu(&inode->i_rcu, hfsplus_i_callback);
}
#define HFSPLUS_INODE_SIZE sizeof(struct hfsplus_inode_info)
static struct dentry *hfsplus_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_bdev(fs_type, flags, dev_name, data, hfsplus_fill_super);
}
static struct file_system_type hfsplus_fs_type = {
.owner = THIS_MODULE,
.name = "hfsplus",
.mount = hfsplus_mount,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
fs: Limit sys_mount to only request filesystem modules. Modify the request_module to prefix the file system type with "fs-" and add aliases to all of the filesystems that can be built as modules to match. A common practice is to build all of the kernel code and leave code that is not commonly needed as modules, with the result that many users are exposed to any bug anywhere in the kernel. Looking for filesystems with a fs- prefix limits the pool of possible modules that can be loaded by mount to just filesystems trivially making things safer with no real cost. Using aliases means user space can control the policy of which filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. This also addresses a rare but unfortunate problem where the filesystem name is not the same as it's module name and module auto-loading would not work. While writing this patch I saw a handful of such cases. The most significant being autofs that lives in the module autofs4. This is relevant to user namespaces because we can reach the request module in get_fs_type() without having any special permissions, and people get uncomfortable when a user specified string (in this case the filesystem type) goes all of the way to request_module. After having looked at this issue I don't think there is any particular reason to perform any filtering or permission checks beyond making it clear in the module request that we want a filesystem module. The common pattern in the kernel is to call request_module() without regards to the users permissions. In general all a filesystem module does once loaded is call register_filesystem() and go to sleep. Which means there is not much attack surface exposed by loading a filesytem module unless the filesystem is mounted. In a user namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT, which most filesystems do not set today. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Reported-by: Kees Cook <keescook@google.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-03-03 03:39:14 +00:00
MODULE_ALIAS_FS("hfsplus");
static void hfsplus_init_once(void *p)
{
struct hfsplus_inode_info *i = p;
inode_init_once(&i->vfs_inode);
}
static int __init init_hfsplus_fs(void)
{
int err;
hfsplus_inode_cachep = kmem_cache_create("hfsplus_icache",
HFSPLUS_INODE_SIZE, 0, SLAB_HWCACHE_ALIGN,
hfsplus_init_once);
if (!hfsplus_inode_cachep)
return -ENOMEM;
err = hfsplus_create_attr_tree_cache();
if (err)
goto destroy_inode_cache;
err = register_filesystem(&hfsplus_fs_type);
if (err)
goto destroy_attr_tree_cache;
return 0;
destroy_attr_tree_cache:
hfsplus_destroy_attr_tree_cache();
destroy_inode_cache:
kmem_cache_destroy(hfsplus_inode_cachep);
return err;
}
static void __exit exit_hfsplus_fs(void)
{
unregister_filesystem(&hfsplus_fs_type);
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
hfsplus_destroy_attr_tree_cache();
kmem_cache_destroy(hfsplus_inode_cachep);
}
module_init(init_hfsplus_fs)
module_exit(exit_hfsplus_fs)