blob: f69e619807a178c4f3b8281376e9af9cd6c4f6f1 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* linux/drivers/staging/erofs/super.c
*
* Copyright (C) 2017-2018 HUAWEI, Inc.
* http://www.huawei.com/
* Created by Gao Xiang <gaoxiang25@huawei.com>
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of the Linux
* distribution for more details.
*/
#include <linux/module.h>
#include <linux/buffer_head.h>
#include <linux/statfs.h>
#include <linux/parser.h>
#include <linux/seq_file.h>
#include "internal.h"
#define CREATE_TRACE_POINTS
#include <trace/events/erofs.h>
static struct kmem_cache *erofs_inode_cachep __read_mostly;
static void init_once(void *ptr)
{
struct erofs_vnode *vi = ptr;
inode_init_once(&vi->vfs_inode);
}
static int __init erofs_init_inode_cache(void)
{
erofs_inode_cachep = kmem_cache_create("erofs_inode",
sizeof(struct erofs_vnode), 0,
SLAB_RECLAIM_ACCOUNT, init_once);
return erofs_inode_cachep != NULL ? 0 : -ENOMEM;
}
static void erofs_exit_inode_cache(void)
{
BUG_ON(erofs_inode_cachep == NULL);
kmem_cache_destroy(erofs_inode_cachep);
}
static struct inode *alloc_inode(struct super_block *sb)
{
struct erofs_vnode *vi =
kmem_cache_alloc(erofs_inode_cachep, GFP_KERNEL);
if (vi == NULL)
return NULL;
/* zero out everything except vfs_inode */
memset(vi, 0, offsetof(struct erofs_vnode, vfs_inode));
return &vi->vfs_inode;
}
static void i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
struct erofs_vnode *vi = EROFS_V(inode);
/* be careful RCU symlink path (see ext4_inode_info->i_data)! */
if (is_inode_fast_symlink(inode))
kfree(inode->i_link);
kfree(vi->xattr_shared_xattrs);
kmem_cache_free(erofs_inode_cachep, vi);
}
static void destroy_inode(struct inode *inode)
{
call_rcu(&inode->i_rcu, i_callback);
}
static int superblock_read(struct super_block *sb)
{
struct erofs_sb_info *sbi;
struct buffer_head *bh;
struct erofs_super_block *layout;
unsigned int blkszbits;
int ret;
bh = sb_bread(sb, 0);
if (bh == NULL) {
errln("cannot read erofs superblock");
return -EIO;
}
sbi = EROFS_SB(sb);
layout = (struct erofs_super_block *)((u8 *)bh->b_data
+ EROFS_SUPER_OFFSET);
ret = -EINVAL;
if (le32_to_cpu(layout->magic) != EROFS_SUPER_MAGIC_V1) {
errln("cannot find valid erofs superblock");
goto out;
}
blkszbits = layout->blkszbits;
/* 9(512 bytes) + LOG_SECTORS_PER_BLOCK == LOG_BLOCK_SIZE */
if (unlikely(blkszbits != LOG_BLOCK_SIZE)) {
errln("blksize %u isn't supported on this platform",
1 << blkszbits);
goto out;
}
sbi->blocks = le32_to_cpu(layout->blocks);
sbi->meta_blkaddr = le32_to_cpu(layout->meta_blkaddr);
#ifdef CONFIG_EROFS_FS_XATTR
sbi->xattr_blkaddr = le32_to_cpu(layout->xattr_blkaddr);
#endif
sbi->islotbits = ffs(sizeof(struct erofs_inode_v1)) - 1;
#ifdef CONFIG_EROFS_FS_ZIP
/* TODO: clusterbits should be related to inode */
sbi->clusterbits = blkszbits;
if (1 << (sbi->clusterbits - PAGE_SHIFT) > Z_EROFS_CLUSTER_MAX_PAGES)
errln("clusterbits %u is not supported on this kernel",
sbi->clusterbits);
#endif
sbi->root_nid = le16_to_cpu(layout->root_nid);
sbi->inos = le64_to_cpu(layout->inos);
sbi->build_time = le64_to_cpu(layout->build_time);
sbi->build_time_nsec = le32_to_cpu(layout->build_time_nsec);
memcpy(&sb->s_uuid, layout->uuid, sizeof(layout->uuid));
memcpy(sbi->volume_name, layout->volume_name,
sizeof(layout->volume_name));
ret = 0;
out:
brelse(bh);
return ret;
}
#ifdef CONFIG_EROFS_FAULT_INJECTION
char *erofs_fault_name[FAULT_MAX] = {
[FAULT_KMALLOC] = "kmalloc",
};
static void __erofs_build_fault_attr(struct erofs_sb_info *sbi,
unsigned int rate)
{
struct erofs_fault_info *ffi = &sbi->fault_info;
if (rate) {
atomic_set(&ffi->inject_ops, 0);
ffi->inject_rate = rate;
ffi->inject_type = (1 << FAULT_MAX) - 1;
} else {
memset(ffi, 0, sizeof(struct erofs_fault_info));
}
set_opt(sbi, FAULT_INJECTION);
}
static int erofs_build_fault_attr(struct erofs_sb_info *sbi,
substring_t *args)
{
int rate = 0;
if (args->from && match_int(args, &rate))
return -EINVAL;
__erofs_build_fault_attr(sbi, rate);
return 0;
}
static unsigned int erofs_get_fault_rate(struct erofs_sb_info *sbi)
{
return sbi->fault_info.inject_rate;
}
#else
static void __erofs_build_fault_attr(struct erofs_sb_info *sbi,
unsigned int rate)
{
}
static int erofs_build_fault_attr(struct erofs_sb_info *sbi,
substring_t *args)
{
infoln("fault_injection options not supported");
return 0;
}
static unsigned int erofs_get_fault_rate(struct erofs_sb_info *sbi)
{
return 0;
}
#endif
static void default_options(struct erofs_sb_info *sbi)
{
/* set up some FS parameters */
#ifdef CONFIG_EROFS_FS_ZIP
sbi->max_sync_decompress_pages = DEFAULT_MAX_SYNC_DECOMPRESS_PAGES;
#endif
#ifdef CONFIG_EROFS_FS_XATTR
set_opt(sbi, XATTR_USER);
#endif
#ifdef CONFIG_EROFS_FS_POSIX_ACL
set_opt(sbi, POSIX_ACL);
#endif
}
enum {
Opt_user_xattr,
Opt_nouser_xattr,
Opt_acl,
Opt_noacl,
Opt_fault_injection,
Opt_err
};
static match_table_t erofs_tokens = {
{Opt_user_xattr, "user_xattr"},
{Opt_nouser_xattr, "nouser_xattr"},
{Opt_acl, "acl"},
{Opt_noacl, "noacl"},
{Opt_fault_injection, "fault_injection=%u"},
{Opt_err, NULL}
};
static int parse_options(struct super_block *sb, char *options)
{
substring_t args[MAX_OPT_ARGS];
char *p;
int err;
if (!options)
return 0;
while ((p = strsep(&options, ",")) != NULL) {
int token;
if (!*p)
continue;
args[0].to = args[0].from = NULL;
token = match_token(p, erofs_tokens, args);
switch (token) {
#ifdef CONFIG_EROFS_FS_XATTR
case Opt_user_xattr:
set_opt(EROFS_SB(sb), XATTR_USER);
break;
case Opt_nouser_xattr:
clear_opt(EROFS_SB(sb), XATTR_USER);
break;
#else
case Opt_user_xattr:
infoln("user_xattr options not supported");
break;
case Opt_nouser_xattr:
infoln("nouser_xattr options not supported");
break;
#endif
#ifdef CONFIG_EROFS_FS_POSIX_ACL
case Opt_acl:
set_opt(EROFS_SB(sb), POSIX_ACL);
break;
case Opt_noacl:
clear_opt(EROFS_SB(sb), POSIX_ACL);
break;
#else
case Opt_acl:
infoln("acl options not supported");
break;
case Opt_noacl:
infoln("noacl options not supported");
break;
#endif
case Opt_fault_injection:
err = erofs_build_fault_attr(EROFS_SB(sb), args);
if (err)
return err;
break;
default:
errln("Unrecognized mount option \"%s\" "
"or missing value", p);
return -EINVAL;
}
}
return 0;
}
#ifdef EROFS_FS_HAS_MANAGED_CACHE
static const struct address_space_operations managed_cache_aops;
static int managed_cache_releasepage(struct page *page, gfp_t gfp_mask)
{
int ret = 1; /* 0 - busy */
struct address_space *const mapping = page->mapping;
BUG_ON(!PageLocked(page));
BUG_ON(mapping->a_ops != &managed_cache_aops);
if (PagePrivate(page))
ret = erofs_try_to_free_cached_page(mapping, page);
return ret;
}
static void managed_cache_invalidatepage(struct page *page,
unsigned int offset, unsigned int length)
{
const unsigned int stop = length + offset;
BUG_ON(!PageLocked(page));
/* Check for overflow */
BUG_ON(stop > PAGE_SIZE || stop < length);
if (offset == 0 && stop == PAGE_SIZE)
while (!managed_cache_releasepage(page, GFP_NOFS))
cond_resched();
}
static const struct address_space_operations managed_cache_aops = {
.releasepage = managed_cache_releasepage,
.invalidatepage = managed_cache_invalidatepage,
};
static struct inode *erofs_init_managed_cache(struct super_block *sb)
{
struct inode *inode = new_inode(sb);
if (unlikely(inode == NULL))
return ERR_PTR(-ENOMEM);
set_nlink(inode, 1);
inode->i_size = OFFSET_MAX;
inode->i_mapping->a_ops = &managed_cache_aops;
mapping_set_gfp_mask(inode->i_mapping,
GFP_NOFS | __GFP_HIGHMEM |
__GFP_MOVABLE | __GFP_NOFAIL);
return inode;
}
#endif
static int erofs_read_super(struct super_block *sb,
const char *dev_name, void *data, int silent)
{
struct inode *inode;
struct erofs_sb_info *sbi;
int err = -EINVAL;
infoln("read_super, device -> %s", dev_name);
infoln("options -> %s", (char *)data);
if (unlikely(!sb_set_blocksize(sb, EROFS_BLKSIZ))) {
errln("failed to set erofs blksize");
goto err;
}
sbi = kzalloc(sizeof(struct erofs_sb_info), GFP_KERNEL);
if (unlikely(sbi == NULL)) {
err = -ENOMEM;
goto err;
}
sb->s_fs_info = sbi;
err = superblock_read(sb);
if (err)
goto err_sbread;
sb->s_magic = EROFS_SUPER_MAGIC;
sb->s_flags |= SB_RDONLY | SB_NOATIME;
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_time_gran = 1;
sb->s_op = &erofs_sops;
#ifdef CONFIG_EROFS_FS_XATTR
sb->s_xattr = erofs_xattr_handlers;
#endif
/* set erofs default mount options */
default_options(sbi);
err = parse_options(sb, data);
if (err)
goto err_parseopt;
if (!silent)
infoln("root inode @ nid %llu", ROOT_NID(sbi));
#ifdef CONFIG_EROFS_FS_ZIP
INIT_RADIX_TREE(&sbi->workstn_tree, GFP_ATOMIC);
#endif
#ifdef EROFS_FS_HAS_MANAGED_CACHE
sbi->managed_cache = erofs_init_managed_cache(sb);
if (IS_ERR(sbi->managed_cache)) {
err = PTR_ERR(sbi->managed_cache);
goto err_init_managed_cache;
}
#endif
/* get the root inode */
inode = erofs_iget(sb, ROOT_NID(sbi), true);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto err_iget;
}
if (!S_ISDIR(inode->i_mode)) {
errln("rootino(nid %llu) is not a directory(i_mode %o)",
ROOT_NID(sbi), inode->i_mode);
err = -EINVAL;
goto err_isdir;
}
sb->s_root = d_make_root(inode);
if (sb->s_root == NULL) {
err = -ENOMEM;
goto err_makeroot;
}
/* save the device name to sbi */
sbi->dev_name = __getname();
if (sbi->dev_name == NULL) {
err = -ENOMEM;
goto err_devname;
}
snprintf(sbi->dev_name, PATH_MAX, "%s", dev_name);
sbi->dev_name[PATH_MAX - 1] = '\0';
erofs_register_super(sb);
/*
* We already have a positive dentry, which was instantiated
* by d_make_root. Just need to d_rehash it.
*/
d_rehash(sb->s_root);
if (!silent)
infoln("mounted on %s with opts: %s.", dev_name,
(char *)data);
return 0;
/*
* please add a label for each exit point and use
* the following name convention, thus new features
* can be integrated easily without renaming labels.
*/
err_devname:
dput(sb->s_root);
err_makeroot:
err_isdir:
if (sb->s_root == NULL)
iput(inode);
err_iget:
#ifdef EROFS_FS_HAS_MANAGED_CACHE
iput(sbi->managed_cache);
err_init_managed_cache:
#endif
err_parseopt:
err_sbread:
sb->s_fs_info = NULL;
kfree(sbi);
err:
return err;
}
/*
* could be triggered after deactivate_locked_super()
* is called, thus including umount and failed to initialize.
*/
static void erofs_put_super(struct super_block *sb)
{
struct erofs_sb_info *sbi = EROFS_SB(sb);
/* for cases which are failed in "read_super" */
if (sbi == NULL)
return;
WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC);
infoln("unmounted for %s", sbi->dev_name);
__putname(sbi->dev_name);
#ifdef EROFS_FS_HAS_MANAGED_CACHE
iput(sbi->managed_cache);
#endif
mutex_lock(&sbi->umount_mutex);
#ifdef CONFIG_EROFS_FS_ZIP
erofs_workstation_cleanup_all(sb);
#endif
erofs_unregister_super(sb);
mutex_unlock(&sbi->umount_mutex);
kfree(sbi);
sb->s_fs_info = NULL;
}
struct erofs_mount_private {
const char *dev_name;
char *options;
};
/* support mount_bdev() with options */
static int erofs_fill_super(struct super_block *sb,
void *_priv, int silent)
{
struct erofs_mount_private *priv = _priv;
return erofs_read_super(sb, priv->dev_name,
priv->options, silent);
}
static struct dentry *erofs_mount(
struct file_system_type *fs_type, int flags,
const char *dev_name, void *data)
{
struct erofs_mount_private priv = {
.dev_name = dev_name,
.options = data
};
return mount_bdev(fs_type, flags, dev_name,
&priv, erofs_fill_super);
}
static void erofs_kill_sb(struct super_block *sb)
{
kill_block_super(sb);
}
static struct shrinker erofs_shrinker_info = {
.scan_objects = erofs_shrink_scan,
.count_objects = erofs_shrink_count,
.seeks = DEFAULT_SEEKS,
};
static struct file_system_type erofs_fs_type = {
.owner = THIS_MODULE,
.name = "erofs",
.mount = erofs_mount,
.kill_sb = erofs_kill_sb,
.fs_flags = FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("erofs");
static int __init erofs_module_init(void)
{
int err;
erofs_check_ondisk_layout_definitions();
infoln("initializing erofs " EROFS_VERSION);
err = erofs_init_inode_cache();
if (err)
goto icache_err;
err = register_shrinker(&erofs_shrinker_info);
if (err)
goto shrinker_err;
err = z_erofs_init_zip_subsystem();
if (err)
goto zip_err;
err = register_filesystem(&erofs_fs_type);
if (err)
goto fs_err;
infoln("successfully to initialize erofs");
return 0;
fs_err:
z_erofs_exit_zip_subsystem();
zip_err:
unregister_shrinker(&erofs_shrinker_info);
shrinker_err:
erofs_exit_inode_cache();
icache_err:
return err;
}
static void __exit erofs_module_exit(void)
{
unregister_filesystem(&erofs_fs_type);
z_erofs_exit_zip_subsystem();
unregister_shrinker(&erofs_shrinker_info);
erofs_exit_inode_cache();
infoln("successfully finalize erofs");
}
/* get filesystem statistics */
static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct erofs_sb_info *sbi = EROFS_SB(sb);
u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
buf->f_type = sb->s_magic;
buf->f_bsize = EROFS_BLKSIZ;
buf->f_blocks = sbi->blocks;
buf->f_bfree = buf->f_bavail = 0;
buf->f_files = ULLONG_MAX;
buf->f_ffree = ULLONG_MAX - sbi->inos;
buf->f_namelen = EROFS_NAME_LEN;
buf->f_fsid.val[0] = (u32)id;
buf->f_fsid.val[1] = (u32)(id >> 32);
return 0;
}
static int erofs_show_options(struct seq_file *seq, struct dentry *root)
{
struct erofs_sb_info *sbi __maybe_unused = EROFS_SB(root->d_sb);
#ifdef CONFIG_EROFS_FS_XATTR
if (test_opt(sbi, XATTR_USER))
seq_puts(seq, ",user_xattr");
else
seq_puts(seq, ",nouser_xattr");
#endif
#ifdef CONFIG_EROFS_FS_POSIX_ACL
if (test_opt(sbi, POSIX_ACL))
seq_puts(seq, ",acl");
else
seq_puts(seq, ",noacl");
#endif
if (test_opt(sbi, FAULT_INJECTION))
seq_printf(seq, ",fault_injection=%u",
erofs_get_fault_rate(sbi));
return 0;
}
static int erofs_remount(struct super_block *sb, int *flags, char *data)
{
struct erofs_sb_info *sbi = EROFS_SB(sb);
unsigned int org_mnt_opt = sbi->mount_opt;
unsigned int org_inject_rate = erofs_get_fault_rate(sbi);
int err;
BUG_ON(!sb_rdonly(sb));
err = parse_options(sb, data);
if (err)
goto out;
*flags |= SB_RDONLY;
return 0;
out:
__erofs_build_fault_attr(sbi, org_inject_rate);
sbi->mount_opt = org_mnt_opt;
return err;
}
const struct super_operations erofs_sops = {
.put_super = erofs_put_super,
.alloc_inode = alloc_inode,
.destroy_inode = destroy_inode,
.statfs = erofs_statfs,
.show_options = erofs_show_options,
.remount_fs = erofs_remount,
};
module_init(erofs_module_init);
module_exit(erofs_module_exit);
MODULE_DESCRIPTION("Enhanced ROM File System");
MODULE_AUTHOR("Gao Xiang, Yu Chao, Miao Xie, CONSUMER BG, HUAWEI Inc.");
MODULE_LICENSE("GPL");