mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-06 02:24:14 +08:00
fe7c242357
As Christoph said [1], "This seems to be your only direct use of buffer heads, which while not deprecated are a bit of an ugly step child. So if you can easily avoid creating a buffer_head dependency in a new filesystem I think you should avoid it. " [1] https://lore.kernel.org/r/20190902125109.GA9826@infradead.org/ Reported-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com> Link: https://lore.kernel.org/r/20190904020912.63925-24-gaoxiang25@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
616 lines
14 KiB
C
616 lines
14 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Copyright (C) 2017-2018 HUAWEI, Inc.
|
|
* http://www.huawei.com/
|
|
* Created by Gao Xiang <gaoxiang25@huawei.com>
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/buffer_head.h>
|
|
#include <linux/statfs.h>
|
|
#include <linux/parser.h>
|
|
#include <linux/seq_file.h>
|
|
#include "xattr.h"
|
|
|
|
#define CREATE_TRACE_POINTS
|
|
#include <trace/events/erofs.h>
|
|
|
|
static struct kmem_cache *erofs_inode_cachep __read_mostly;
|
|
|
|
void _erofs_err(struct super_block *sb, const char *function,
|
|
const char *fmt, ...)
|
|
{
|
|
struct va_format vaf;
|
|
va_list args;
|
|
|
|
va_start(args, fmt);
|
|
|
|
vaf.fmt = fmt;
|
|
vaf.va = &args;
|
|
|
|
pr_err("(device %s): %s: %pV", sb->s_id, function, &vaf);
|
|
va_end(args);
|
|
}
|
|
|
|
void _erofs_info(struct super_block *sb, const char *function,
|
|
const char *fmt, ...)
|
|
{
|
|
struct va_format vaf;
|
|
va_list args;
|
|
|
|
va_start(args, fmt);
|
|
|
|
vaf.fmt = fmt;
|
|
vaf.va = &args;
|
|
|
|
pr_info("(device %s): %pV", sb->s_id, &vaf);
|
|
va_end(args);
|
|
}
|
|
|
|
static void erofs_inode_init_once(void *ptr)
|
|
{
|
|
struct erofs_inode *vi = ptr;
|
|
|
|
inode_init_once(&vi->vfs_inode);
|
|
}
|
|
|
|
static struct inode *erofs_alloc_inode(struct super_block *sb)
|
|
{
|
|
struct erofs_inode *vi =
|
|
kmem_cache_alloc(erofs_inode_cachep, GFP_KERNEL);
|
|
|
|
if (!vi)
|
|
return NULL;
|
|
|
|
/* zero out everything except vfs_inode */
|
|
memset(vi, 0, offsetof(struct erofs_inode, vfs_inode));
|
|
return &vi->vfs_inode;
|
|
}
|
|
|
|
static void erofs_free_inode(struct inode *inode)
|
|
{
|
|
struct erofs_inode *vi = EROFS_I(inode);
|
|
|
|
/* be careful of RCU symlink path */
|
|
if (inode->i_op == &erofs_fast_symlink_iops)
|
|
kfree(inode->i_link);
|
|
kfree(vi->xattr_shared_xattrs);
|
|
|
|
kmem_cache_free(erofs_inode_cachep, vi);
|
|
}
|
|
|
|
static bool check_layout_compatibility(struct super_block *sb,
|
|
struct erofs_super_block *dsb)
|
|
{
|
|
const unsigned int feature = le32_to_cpu(dsb->feature_incompat);
|
|
|
|
EROFS_SB(sb)->feature_incompat = feature;
|
|
|
|
/* check if current kernel meets all mandatory requirements */
|
|
if (feature & (~EROFS_ALL_FEATURE_INCOMPAT)) {
|
|
erofs_err(sb,
|
|
"unidentified incompatible feature %x, please upgrade kernel version",
|
|
feature & ~EROFS_ALL_FEATURE_INCOMPAT);
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static int erofs_read_superblock(struct super_block *sb)
|
|
{
|
|
struct erofs_sb_info *sbi;
|
|
struct page *page;
|
|
struct erofs_super_block *dsb;
|
|
unsigned int blkszbits;
|
|
void *data;
|
|
int ret;
|
|
|
|
page = read_mapping_page(sb->s_bdev->bd_inode->i_mapping, 0, NULL);
|
|
if (!page) {
|
|
erofs_err(sb, "cannot read erofs superblock");
|
|
return -EIO;
|
|
}
|
|
|
|
sbi = EROFS_SB(sb);
|
|
|
|
data = kmap_atomic(page);
|
|
dsb = (struct erofs_super_block *)(data + EROFS_SUPER_OFFSET);
|
|
|
|
ret = -EINVAL;
|
|
if (le32_to_cpu(dsb->magic) != EROFS_SUPER_MAGIC_V1) {
|
|
erofs_err(sb, "cannot find valid erofs superblock");
|
|
goto out;
|
|
}
|
|
|
|
blkszbits = dsb->blkszbits;
|
|
/* 9(512 bytes) + LOG_SECTORS_PER_BLOCK == LOG_BLOCK_SIZE */
|
|
if (blkszbits != LOG_BLOCK_SIZE) {
|
|
erofs_err(sb, "blksize %u isn't supported on this platform",
|
|
1 << blkszbits);
|
|
goto out;
|
|
}
|
|
|
|
if (!check_layout_compatibility(sb, dsb))
|
|
goto out;
|
|
|
|
sbi->blocks = le32_to_cpu(dsb->blocks);
|
|
sbi->meta_blkaddr = le32_to_cpu(dsb->meta_blkaddr);
|
|
#ifdef CONFIG_EROFS_FS_XATTR
|
|
sbi->xattr_blkaddr = le32_to_cpu(dsb->xattr_blkaddr);
|
|
#endif
|
|
sbi->islotbits = ilog2(sizeof(struct erofs_inode_compact));
|
|
sbi->root_nid = le16_to_cpu(dsb->root_nid);
|
|
sbi->inos = le64_to_cpu(dsb->inos);
|
|
|
|
sbi->build_time = le64_to_cpu(dsb->build_time);
|
|
sbi->build_time_nsec = le32_to_cpu(dsb->build_time_nsec);
|
|
|
|
memcpy(&sb->s_uuid, dsb->uuid, sizeof(dsb->uuid));
|
|
|
|
ret = strscpy(sbi->volume_name, dsb->volume_name,
|
|
sizeof(dsb->volume_name));
|
|
if (ret < 0) { /* -E2BIG */
|
|
erofs_err(sb, "bad volume name without NIL terminator");
|
|
ret = -EFSCORRUPTED;
|
|
goto out;
|
|
}
|
|
ret = 0;
|
|
out:
|
|
kunmap_atomic(data);
|
|
put_page(page);
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_EROFS_FS_ZIP
|
|
static int erofs_build_cache_strategy(struct super_block *sb,
|
|
substring_t *args)
|
|
{
|
|
struct erofs_sb_info *sbi = EROFS_SB(sb);
|
|
const char *cs = match_strdup(args);
|
|
int err = 0;
|
|
|
|
if (!cs) {
|
|
erofs_err(sb, "Not enough memory to store cache strategy");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
if (!strcmp(cs, "disabled")) {
|
|
sbi->cache_strategy = EROFS_ZIP_CACHE_DISABLED;
|
|
} else if (!strcmp(cs, "readahead")) {
|
|
sbi->cache_strategy = EROFS_ZIP_CACHE_READAHEAD;
|
|
} else if (!strcmp(cs, "readaround")) {
|
|
sbi->cache_strategy = EROFS_ZIP_CACHE_READAROUND;
|
|
} else {
|
|
erofs_err(sb, "Unrecognized cache strategy \"%s\"", cs);
|
|
err = -EINVAL;
|
|
}
|
|
kfree(cs);
|
|
return err;
|
|
}
|
|
#else
|
|
static int erofs_build_cache_strategy(struct super_block *sb,
|
|
substring_t *args)
|
|
{
|
|
erofs_info(sb, "EROFS compression is disabled, so cache strategy is ignored");
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
/* set up default EROFS parameters */
|
|
static void erofs_default_options(struct erofs_sb_info *sbi)
|
|
{
|
|
#ifdef CONFIG_EROFS_FS_ZIP
|
|
sbi->cache_strategy = EROFS_ZIP_CACHE_READAROUND;
|
|
sbi->max_sync_decompress_pages = 3;
|
|
#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_cache_strategy,
|
|
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_cache_strategy, "cache_strategy=%s"},
|
|
{Opt_err, NULL}
|
|
};
|
|
|
|
static int erofs_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, ","))) {
|
|
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:
|
|
erofs_info(sb, "user_xattr options not supported");
|
|
break;
|
|
case Opt_nouser_xattr:
|
|
erofs_info(sb, "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:
|
|
erofs_info(sb, "acl options not supported");
|
|
break;
|
|
case Opt_noacl:
|
|
erofs_info(sb, "noacl options not supported");
|
|
break;
|
|
#endif
|
|
case Opt_cache_strategy:
|
|
err = erofs_build_cache_strategy(sb, args);
|
|
if (err)
|
|
return err;
|
|
break;
|
|
default:
|
|
erofs_err(sb, "Unrecognized mount option \"%s\" or missing value", p);
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_EROFS_FS_ZIP
|
|
static const struct address_space_operations managed_cache_aops;
|
|
|
|
static int erofs_managed_cache_releasepage(struct page *page, gfp_t gfp_mask)
|
|
{
|
|
int ret = 1; /* 0 - busy */
|
|
struct address_space *const mapping = page->mapping;
|
|
|
|
DBG_BUGON(!PageLocked(page));
|
|
DBG_BUGON(mapping->a_ops != &managed_cache_aops);
|
|
|
|
if (PagePrivate(page))
|
|
ret = erofs_try_to_free_cached_page(mapping, page);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void erofs_managed_cache_invalidatepage(struct page *page,
|
|
unsigned int offset,
|
|
unsigned int length)
|
|
{
|
|
const unsigned int stop = length + offset;
|
|
|
|
DBG_BUGON(!PageLocked(page));
|
|
|
|
/* Check for potential overflow in debug mode */
|
|
DBG_BUGON(stop > PAGE_SIZE || stop < length);
|
|
|
|
if (offset == 0 && stop == PAGE_SIZE)
|
|
while (!erofs_managed_cache_releasepage(page, GFP_NOFS))
|
|
cond_resched();
|
|
}
|
|
|
|
static const struct address_space_operations managed_cache_aops = {
|
|
.releasepage = erofs_managed_cache_releasepage,
|
|
.invalidatepage = erofs_managed_cache_invalidatepage,
|
|
};
|
|
|
|
static int erofs_init_managed_cache(struct super_block *sb)
|
|
{
|
|
struct erofs_sb_info *const sbi = EROFS_SB(sb);
|
|
struct inode *const inode = new_inode(sb);
|
|
|
|
if (!inode)
|
|
return -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);
|
|
sbi->managed_cache = inode;
|
|
return 0;
|
|
}
|
|
#else
|
|
static int erofs_init_managed_cache(struct super_block *sb) { return 0; }
|
|
#endif
|
|
|
|
static int erofs_fill_super(struct super_block *sb, void *data, int silent)
|
|
{
|
|
struct inode *inode;
|
|
struct erofs_sb_info *sbi;
|
|
int err;
|
|
|
|
sb->s_magic = EROFS_SUPER_MAGIC;
|
|
|
|
if (!sb_set_blocksize(sb, EROFS_BLKSIZ)) {
|
|
erofs_err(sb, "failed to set erofs blksize");
|
|
return -EINVAL;
|
|
}
|
|
|
|
sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
|
|
if (!sbi)
|
|
return -ENOMEM;
|
|
|
|
sb->s_fs_info = sbi;
|
|
err = erofs_read_superblock(sb);
|
|
if (err)
|
|
return err;
|
|
|
|
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 */
|
|
erofs_default_options(sbi);
|
|
|
|
err = erofs_parse_options(sb, data);
|
|
if (err)
|
|
return err;
|
|
|
|
if (test_opt(sbi, POSIX_ACL))
|
|
sb->s_flags |= SB_POSIXACL;
|
|
else
|
|
sb->s_flags &= ~SB_POSIXACL;
|
|
|
|
#ifdef CONFIG_EROFS_FS_ZIP
|
|
INIT_RADIX_TREE(&sbi->workstn_tree, GFP_ATOMIC);
|
|
#endif
|
|
|
|
/* get the root inode */
|
|
inode = erofs_iget(sb, ROOT_NID(sbi), true);
|
|
if (IS_ERR(inode))
|
|
return PTR_ERR(inode);
|
|
|
|
if (!S_ISDIR(inode->i_mode)) {
|
|
erofs_err(sb, "rootino(nid %llu) is not a directory(i_mode %o)",
|
|
ROOT_NID(sbi), inode->i_mode);
|
|
iput(inode);
|
|
return -EINVAL;
|
|
}
|
|
|
|
sb->s_root = d_make_root(inode);
|
|
if (!sb->s_root)
|
|
return -ENOMEM;
|
|
|
|
erofs_shrinker_register(sb);
|
|
/* sb->s_umount is already locked, SB_ACTIVE and SB_BORN are not set */
|
|
err = erofs_init_managed_cache(sb);
|
|
if (err)
|
|
return err;
|
|
|
|
erofs_info(sb, "mounted with opts: %s, root inode @ nid %llu.",
|
|
(char *)data, ROOT_NID(sbi));
|
|
return 0;
|
|
}
|
|
|
|
static struct dentry *erofs_mount(struct file_system_type *fs_type, int flags,
|
|
const char *dev_name, void *data)
|
|
{
|
|
return mount_bdev(fs_type, flags, dev_name, data, erofs_fill_super);
|
|
}
|
|
|
|
/*
|
|
* could be triggered after deactivate_locked_super()
|
|
* is called, thus including umount and failed to initialize.
|
|
*/
|
|
static void erofs_kill_sb(struct super_block *sb)
|
|
{
|
|
struct erofs_sb_info *sbi;
|
|
|
|
WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC);
|
|
|
|
kill_block_super(sb);
|
|
|
|
sbi = EROFS_SB(sb);
|
|
if (!sbi)
|
|
return;
|
|
kfree(sbi);
|
|
sb->s_fs_info = NULL;
|
|
}
|
|
|
|
/* called when ->s_root is non-NULL */
|
|
static void erofs_put_super(struct super_block *sb)
|
|
{
|
|
struct erofs_sb_info *const sbi = EROFS_SB(sb);
|
|
|
|
DBG_BUGON(!sbi);
|
|
|
|
erofs_shrinker_unregister(sb);
|
|
#ifdef CONFIG_EROFS_FS_ZIP
|
|
iput(sbi->managed_cache);
|
|
sbi->managed_cache = NULL;
|
|
#endif
|
|
}
|
|
|
|
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();
|
|
|
|
erofs_inode_cachep = kmem_cache_create("erofs_inode",
|
|
sizeof(struct erofs_inode), 0,
|
|
SLAB_RECLAIM_ACCOUNT,
|
|
erofs_inode_init_once);
|
|
if (!erofs_inode_cachep) {
|
|
err = -ENOMEM;
|
|
goto icache_err;
|
|
}
|
|
|
|
err = erofs_init_shrinker();
|
|
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;
|
|
|
|
return 0;
|
|
|
|
fs_err:
|
|
z_erofs_exit_zip_subsystem();
|
|
zip_err:
|
|
erofs_exit_shrinker();
|
|
shrinker_err:
|
|
kmem_cache_destroy(erofs_inode_cachep);
|
|
icache_err:
|
|
return err;
|
|
}
|
|
|
|
static void __exit erofs_module_exit(void)
|
|
{
|
|
unregister_filesystem(&erofs_fs_type);
|
|
z_erofs_exit_zip_subsystem();
|
|
erofs_exit_shrinker();
|
|
|
|
/* Ensure all RCU free inodes are safe before cache is destroyed. */
|
|
rcu_barrier();
|
|
kmem_cache_destroy(erofs_inode_cachep);
|
|
}
|
|
|
|
/* 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
|
|
#ifdef CONFIG_EROFS_FS_ZIP
|
|
if (sbi->cache_strategy == EROFS_ZIP_CACHE_DISABLED) {
|
|
seq_puts(seq, ",cache_strategy=disabled");
|
|
} else if (sbi->cache_strategy == EROFS_ZIP_CACHE_READAHEAD) {
|
|
seq_puts(seq, ",cache_strategy=readahead");
|
|
} else if (sbi->cache_strategy == EROFS_ZIP_CACHE_READAROUND) {
|
|
seq_puts(seq, ",cache_strategy=readaround");
|
|
} else {
|
|
seq_puts(seq, ",cache_strategy=(unknown)");
|
|
DBG_BUGON(1);
|
|
}
|
|
#endif
|
|
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;
|
|
int err;
|
|
|
|
DBG_BUGON(!sb_rdonly(sb));
|
|
err = erofs_parse_options(sb, data);
|
|
if (err)
|
|
goto out;
|
|
|
|
if (test_opt(sbi, POSIX_ACL))
|
|
sb->s_flags |= SB_POSIXACL;
|
|
else
|
|
sb->s_flags &= ~SB_POSIXACL;
|
|
|
|
*flags |= SB_RDONLY;
|
|
return 0;
|
|
out:
|
|
sbi->mount_opt = org_mnt_opt;
|
|
return err;
|
|
}
|
|
|
|
const struct super_operations erofs_sops = {
|
|
.put_super = erofs_put_super,
|
|
.alloc_inode = erofs_alloc_inode,
|
|
.free_inode = erofs_free_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, Chao Yu, Miao Xie, CONSUMER BG, HUAWEI Inc.");
|
|
MODULE_LICENSE("GPL");
|
|
|