linux/fs/befs/linuxvfs.c
Linus Torvalds 13d88ac54d vfs-6.7.fsid
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Merge tag 'vfs-6.7.fsid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs fanotify fsid updates from Christian Brauner:
 "This work is part of the plan to enable fanotify to serve as a drop-in
  replacement for inotify. While inotify is availabe on all filesystems,
  fanotify currently isn't.

  In order to support fanotify on all filesystems two things are needed:

   (1) all filesystems need to support AT_HANDLE_FID

   (2) all filesystems need to report a non-zero f_fsid

  This contains (1) and allows filesystems to encode non-decodable file
  handlers for fanotify without implementing any exportfs operations by
  encoding a file id of type FILEID_INO64_GEN from i_ino and
  i_generation.

  Filesystems that want to opt out of encoding non-decodable file ids
  for fanotify that don't support NFS export can do so by providing an
  empty export_operations struct.

  This also partially addresses (2) by generating f_fsid for simple
  filesystems as well as freevxfs. Remaining filesystems will be dealt
  with by separate patches.

  Finally, this contains the patch from the current exportfs maintainers
  which moves exportfs under vfs with Chuck, Jeff, and Amir as
  maintainers and vfs.git as tree"

* tag 'vfs-6.7.fsid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  MAINTAINERS: create an entry for exportfs
  fs: fix build error with CONFIG_EXPORTFS=m or not defined
  freevxfs: derive f_fsid from bdev->bd_dev
  fs: report f_fsid from s_dev for "simple" filesystems
  exportfs: support encoding non-decodeable file handles by default
  exportfs: define FILEID_INO64_GEN* file handle types
  exportfs: make ->encode_fh() a mandatory method for NFS export
  exportfs: add helpers to check if filesystem can encode/decode file handles
2023-11-07 12:11:26 -08:00

1029 lines
26 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/fs/befs/linuxvfs.c
*
* Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/stat.h>
#include <linux/nls.h>
#include <linux/buffer_head.h>
#include <linux/vfs.h>
#include <linux/parser.h>
#include <linux/namei.h>
#include <linux/sched.h>
#include <linux/cred.h>
#include <linux/exportfs.h>
#include <linux/seq_file.h>
#include <linux/blkdev.h>
#include "befs.h"
#include "btree.h"
#include "inode.h"
#include "datastream.h"
#include "super.h"
#include "io.h"
MODULE_DESCRIPTION("BeOS File System (BeFS) driver");
MODULE_AUTHOR("Will Dyson");
MODULE_LICENSE("GPL");
/* The units the vfs expects inode->i_blocks to be in */
#define VFS_BLOCK_SIZE 512
static int befs_readdir(struct file *, struct dir_context *);
static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
static int befs_read_folio(struct file *file, struct folio *folio);
static sector_t befs_bmap(struct address_space *mapping, sector_t block);
static struct dentry *befs_lookup(struct inode *, struct dentry *,
unsigned int);
static struct inode *befs_iget(struct super_block *, unsigned long);
static struct inode *befs_alloc_inode(struct super_block *sb);
static void befs_free_inode(struct inode *inode);
static void befs_destroy_inodecache(void);
static int befs_symlink_read_folio(struct file *, struct folio *);
static int befs_utf2nls(struct super_block *sb, const char *in, int in_len,
char **out, int *out_len);
static int befs_nls2utf(struct super_block *sb, const char *in, int in_len,
char **out, int *out_len);
static void befs_put_super(struct super_block *);
static int befs_remount(struct super_block *, int *, char *);
static int befs_statfs(struct dentry *, struct kstatfs *);
static int befs_show_options(struct seq_file *, struct dentry *);
static int parse_options(char *, struct befs_mount_options *);
static struct dentry *befs_fh_to_dentry(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type);
static struct dentry *befs_fh_to_parent(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type);
static struct dentry *befs_get_parent(struct dentry *child);
static const struct super_operations befs_sops = {
.alloc_inode = befs_alloc_inode, /* allocate a new inode */
.free_inode = befs_free_inode, /* deallocate an inode */
.put_super = befs_put_super, /* uninit super */
.statfs = befs_statfs, /* statfs */
.remount_fs = befs_remount,
.show_options = befs_show_options,
};
/* slab cache for befs_inode_info objects */
static struct kmem_cache *befs_inode_cachep;
static const struct file_operations befs_dir_operations = {
.read = generic_read_dir,
.iterate_shared = befs_readdir,
.llseek = generic_file_llseek,
};
static const struct inode_operations befs_dir_inode_operations = {
.lookup = befs_lookup,
};
static const struct address_space_operations befs_aops = {
.read_folio = befs_read_folio,
.bmap = befs_bmap,
};
static const struct address_space_operations befs_symlink_aops = {
.read_folio = befs_symlink_read_folio,
};
static const struct export_operations befs_export_operations = {
.encode_fh = generic_encode_ino32_fh,
.fh_to_dentry = befs_fh_to_dentry,
.fh_to_parent = befs_fh_to_parent,
.get_parent = befs_get_parent,
};
/*
* Called by generic_file_read() to read a folio of data
*
* In turn, simply calls a generic block read function and
* passes it the address of befs_get_block, for mapping file
* positions to disk blocks.
*/
static int befs_read_folio(struct file *file, struct folio *folio)
{
return block_read_full_folio(folio, befs_get_block);
}
static sector_t
befs_bmap(struct address_space *mapping, sector_t block)
{
return generic_block_bmap(mapping, block, befs_get_block);
}
/*
* Generic function to map a file position (block) to a
* disk offset (passed back in bh_result).
*
* Used by many higher level functions.
*
* Calls befs_fblock2brun() in datastream.c to do the real work.
*/
static int
befs_get_block(struct inode *inode, sector_t block,
struct buffer_head *bh_result, int create)
{
struct super_block *sb = inode->i_sb;
befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
befs_block_run run = BAD_IADDR;
int res;
ulong disk_off;
befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
(unsigned long)inode->i_ino, (long)block);
if (create) {
befs_error(sb, "befs_get_block() was asked to write to "
"block %ld in inode %lu", (long)block,
(unsigned long)inode->i_ino);
return -EPERM;
}
res = befs_fblock2brun(sb, ds, block, &run);
if (res != BEFS_OK) {
befs_error(sb,
"<--- %s for inode %lu, block %ld ERROR",
__func__, (unsigned long)inode->i_ino,
(long)block);
return -EFBIG;
}
disk_off = (ulong) iaddr2blockno(sb, &run);
map_bh(bh_result, inode->i_sb, disk_off);
befs_debug(sb, "<--- %s for inode %lu, block %ld, disk address %lu",
__func__, (unsigned long)inode->i_ino, (long)block,
(unsigned long)disk_off);
return 0;
}
static struct dentry *
befs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
struct inode *inode;
struct super_block *sb = dir->i_sb;
const befs_data_stream *ds = &BEFS_I(dir)->i_data.ds;
befs_off_t offset;
int ret;
int utfnamelen;
char *utfname;
const char *name = dentry->d_name.name;
befs_debug(sb, "---> %s name %pd inode %ld", __func__,
dentry, dir->i_ino);
/* Convert to UTF-8 */
if (BEFS_SB(sb)->nls) {
ret =
befs_nls2utf(sb, name, strlen(name), &utfname, &utfnamelen);
if (ret < 0) {
befs_debug(sb, "<--- %s ERROR", __func__);
return ERR_PTR(ret);
}
ret = befs_btree_find(sb, ds, utfname, &offset);
kfree(utfname);
} else {
ret = befs_btree_find(sb, ds, name, &offset);
}
if (ret == BEFS_BT_NOT_FOUND) {
befs_debug(sb, "<--- %s %pd not found", __func__, dentry);
inode = NULL;
} else if (ret != BEFS_OK || offset == 0) {
befs_error(sb, "<--- %s Error", __func__);
inode = ERR_PTR(-ENODATA);
} else {
inode = befs_iget(dir->i_sb, (ino_t) offset);
}
befs_debug(sb, "<--- %s", __func__);
return d_splice_alias(inode, dentry);
}
static int
befs_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
struct super_block *sb = inode->i_sb;
const befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
befs_off_t value;
int result;
size_t keysize;
char keybuf[BEFS_NAME_LEN + 1];
befs_debug(sb, "---> %s name %pD, inode %ld, ctx->pos %lld",
__func__, file, inode->i_ino, ctx->pos);
while (1) {
result = befs_btree_read(sb, ds, ctx->pos, BEFS_NAME_LEN + 1,
keybuf, &keysize, &value);
if (result == BEFS_ERR) {
befs_debug(sb, "<--- %s ERROR", __func__);
befs_error(sb, "IO error reading %pD (inode %lu)",
file, inode->i_ino);
return -EIO;
} else if (result == BEFS_BT_END) {
befs_debug(sb, "<--- %s END", __func__);
return 0;
} else if (result == BEFS_BT_EMPTY) {
befs_debug(sb, "<--- %s Empty directory", __func__);
return 0;
}
/* Convert to NLS */
if (BEFS_SB(sb)->nls) {
char *nlsname;
int nlsnamelen;
result =
befs_utf2nls(sb, keybuf, keysize, &nlsname,
&nlsnamelen);
if (result < 0) {
befs_debug(sb, "<--- %s ERROR", __func__);
return result;
}
if (!dir_emit(ctx, nlsname, nlsnamelen,
(ino_t) value, DT_UNKNOWN)) {
kfree(nlsname);
return 0;
}
kfree(nlsname);
} else {
if (!dir_emit(ctx, keybuf, keysize,
(ino_t) value, DT_UNKNOWN))
return 0;
}
ctx->pos++;
}
}
static struct inode *
befs_alloc_inode(struct super_block *sb)
{
struct befs_inode_info *bi;
bi = alloc_inode_sb(sb, befs_inode_cachep, GFP_KERNEL);
if (!bi)
return NULL;
return &bi->vfs_inode;
}
static void befs_free_inode(struct inode *inode)
{
kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
}
static void init_once(void *foo)
{
struct befs_inode_info *bi = (struct befs_inode_info *) foo;
inode_init_once(&bi->vfs_inode);
}
static struct inode *befs_iget(struct super_block *sb, unsigned long ino)
{
struct buffer_head *bh;
befs_inode *raw_inode;
struct befs_sb_info *befs_sb = BEFS_SB(sb);
struct befs_inode_info *befs_ino;
struct inode *inode;
befs_debug(sb, "---> %s inode = %lu", __func__, ino);
inode = iget_locked(sb, ino);
if (!inode)
return ERR_PTR(-ENOMEM);
if (!(inode->i_state & I_NEW))
return inode;
befs_ino = BEFS_I(inode);
/* convert from vfs's inode number to befs's inode number */
befs_ino->i_inode_num = blockno2iaddr(sb, inode->i_ino);
befs_debug(sb, " real inode number [%u, %hu, %hu]",
befs_ino->i_inode_num.allocation_group,
befs_ino->i_inode_num.start, befs_ino->i_inode_num.len);
bh = sb_bread(sb, inode->i_ino);
if (!bh) {
befs_error(sb, "unable to read inode block - "
"inode = %lu", inode->i_ino);
goto unacquire_none;
}
raw_inode = (befs_inode *) bh->b_data;
befs_dump_inode(sb, raw_inode);
if (befs_check_inode(sb, raw_inode, inode->i_ino) != BEFS_OK) {
befs_error(sb, "Bad inode: %lu", inode->i_ino);
goto unacquire_bh;
}
inode->i_mode = (umode_t) fs32_to_cpu(sb, raw_inode->mode);
/*
* set uid and gid. But since current BeOS is single user OS, so
* you can change by "uid" or "gid" options.
*/
inode->i_uid = befs_sb->mount_opts.use_uid ?
befs_sb->mount_opts.uid :
make_kuid(&init_user_ns, fs32_to_cpu(sb, raw_inode->uid));
inode->i_gid = befs_sb->mount_opts.use_gid ?
befs_sb->mount_opts.gid :
make_kgid(&init_user_ns, fs32_to_cpu(sb, raw_inode->gid));
set_nlink(inode, 1);
/*
* BEFS's time is 64 bits, but current VFS is 32 bits...
* BEFS don't have access time. Nor inode change time. VFS
* doesn't have creation time.
* Also, the lower 16 bits of the last_modified_time and
* create_time are just a counter to help ensure uniqueness
* for indexing purposes. (PFD, page 54)
*/
inode_set_mtime(inode,
fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16,
0);/* lower 16 bits are not a time */
inode_set_ctime_to_ts(inode, inode_get_mtime(inode));
inode_set_atime_to_ts(inode, inode_get_mtime(inode));
befs_ino->i_inode_num = fsrun_to_cpu(sb, raw_inode->inode_num);
befs_ino->i_parent = fsrun_to_cpu(sb, raw_inode->parent);
befs_ino->i_attribute = fsrun_to_cpu(sb, raw_inode->attributes);
befs_ino->i_flags = fs32_to_cpu(sb, raw_inode->flags);
if (S_ISLNK(inode->i_mode) && !(befs_ino->i_flags & BEFS_LONG_SYMLINK)){
inode->i_size = 0;
inode->i_blocks = befs_sb->block_size / VFS_BLOCK_SIZE;
strscpy(befs_ino->i_data.symlink, raw_inode->data.symlink,
BEFS_SYMLINK_LEN);
} else {
int num_blks;
befs_ino->i_data.ds =
fsds_to_cpu(sb, &raw_inode->data.datastream);
num_blks = befs_count_blocks(sb, &befs_ino->i_data.ds);
inode->i_blocks =
num_blks * (befs_sb->block_size / VFS_BLOCK_SIZE);
inode->i_size = befs_ino->i_data.ds.size;
}
inode->i_mapping->a_ops = &befs_aops;
if (S_ISREG(inode->i_mode)) {
inode->i_fop = &generic_ro_fops;
} else if (S_ISDIR(inode->i_mode)) {
inode->i_op = &befs_dir_inode_operations;
inode->i_fop = &befs_dir_operations;
} else if (S_ISLNK(inode->i_mode)) {
if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
inode->i_op = &page_symlink_inode_operations;
inode_nohighmem(inode);
inode->i_mapping->a_ops = &befs_symlink_aops;
} else {
inode->i_link = befs_ino->i_data.symlink;
inode->i_op = &simple_symlink_inode_operations;
}
} else {
befs_error(sb, "Inode %lu is not a regular file, "
"directory or symlink. THAT IS WRONG! BeFS has no "
"on disk special files", inode->i_ino);
goto unacquire_bh;
}
brelse(bh);
befs_debug(sb, "<--- %s", __func__);
unlock_new_inode(inode);
return inode;
unacquire_bh:
brelse(bh);
unacquire_none:
iget_failed(inode);
befs_debug(sb, "<--- %s - Bad inode", __func__);
return ERR_PTR(-EIO);
}
/* Initialize the inode cache. Called at fs setup.
*
* Taken from NFS implementation by Al Viro.
*/
static int __init
befs_init_inodecache(void)
{
befs_inode_cachep = kmem_cache_create_usercopy("befs_inode_cache",
sizeof(struct befs_inode_info), 0,
(SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
SLAB_ACCOUNT),
offsetof(struct befs_inode_info,
i_data.symlink),
sizeof_field(struct befs_inode_info,
i_data.symlink),
init_once);
if (befs_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
/* Called at fs teardown.
*
* Taken from NFS implementation by Al Viro.
*/
static void
befs_destroy_inodecache(void)
{
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(befs_inode_cachep);
}
/*
* The inode of symbolic link is different to data stream.
* The data stream become link name. Unless the LONG_SYMLINK
* flag is set.
*/
static int befs_symlink_read_folio(struct file *unused, struct folio *folio)
{
struct inode *inode = folio->mapping->host;
struct super_block *sb = inode->i_sb;
struct befs_inode_info *befs_ino = BEFS_I(inode);
befs_data_stream *data = &befs_ino->i_data.ds;
befs_off_t len = data->size;
char *link = folio_address(folio);
if (len == 0 || len > PAGE_SIZE) {
befs_error(sb, "Long symlink with illegal length");
goto fail;
}
befs_debug(sb, "Follow long symlink");
if (befs_read_lsymlink(sb, data, link, len) != len) {
befs_error(sb, "Failed to read entire long symlink");
goto fail;
}
link[len - 1] = '\0';
folio_mark_uptodate(folio);
folio_unlock(folio);
return 0;
fail:
folio_set_error(folio);
folio_unlock(folio);
return -EIO;
}
/*
* UTF-8 to NLS charset convert routine
*
* Uses uni2char() / char2uni() rather than the nls tables directly
*/
static int
befs_utf2nls(struct super_block *sb, const char *in,
int in_len, char **out, int *out_len)
{
struct nls_table *nls = BEFS_SB(sb)->nls;
int i, o;
unicode_t uni;
int unilen, utflen;
char *result;
/* The utf8->nls conversion won't make the final nls string bigger
* than the utf one, but if the string is pure ascii they'll have the
* same width and an extra char is needed to save the additional \0
*/
int maxlen = in_len + 1;
befs_debug(sb, "---> %s", __func__);
if (!nls) {
befs_error(sb, "%s called with no NLS table loaded", __func__);
return -EINVAL;
}
*out = result = kmalloc(maxlen, GFP_NOFS);
if (!*out)
return -ENOMEM;
for (i = o = 0; i < in_len; i += utflen, o += unilen) {
/* convert from UTF-8 to Unicode */
utflen = utf8_to_utf32(&in[i], in_len - i, &uni);
if (utflen < 0)
goto conv_err;
/* convert from Unicode to nls */
if (uni > MAX_WCHAR_T)
goto conv_err;
unilen = nls->uni2char(uni, &result[o], in_len - o);
if (unilen < 0)
goto conv_err;
}
result[o] = '\0';
*out_len = o;
befs_debug(sb, "<--- %s", __func__);
return o;
conv_err:
befs_error(sb, "Name using character set %s contains a character that "
"cannot be converted to unicode.", nls->charset);
befs_debug(sb, "<--- %s", __func__);
kfree(result);
return -EILSEQ;
}
/**
* befs_nls2utf - Convert NLS string to utf8 encodeing
* @sb: Superblock
* @in: Input string buffer in NLS format
* @in_len: Length of input string in bytes
* @out: The output string in UTF-8 format
* @out_len: Length of the output buffer
*
* Converts input string @in, which is in the format of the loaded NLS map,
* into a utf8 string.
*
* The destination string @out is allocated by this function and the caller is
* responsible for freeing it with kfree()
*
* On return, *@out_len is the length of @out in bytes.
*
* On success, the return value is the number of utf8 characters written to
* the output buffer @out.
*
* On Failure, a negative number coresponding to the error code is returned.
*/
static int
befs_nls2utf(struct super_block *sb, const char *in,
int in_len, char **out, int *out_len)
{
struct nls_table *nls = BEFS_SB(sb)->nls;
int i, o;
wchar_t uni;
int unilen, utflen;
char *result;
/*
* There are nls characters that will translate to 3-chars-wide UTF-8
* characters, an additional byte is needed to save the final \0
* in special cases
*/
int maxlen = (3 * in_len) + 1;
befs_debug(sb, "---> %s\n", __func__);
if (!nls) {
befs_error(sb, "%s called with no NLS table loaded.",
__func__);
return -EINVAL;
}
*out = result = kmalloc(maxlen, GFP_NOFS);
if (!*out) {
*out_len = 0;
return -ENOMEM;
}
for (i = o = 0; i < in_len; i += unilen, o += utflen) {
/* convert from nls to unicode */
unilen = nls->char2uni(&in[i], in_len - i, &uni);
if (unilen < 0)
goto conv_err;
/* convert from unicode to UTF-8 */
utflen = utf32_to_utf8(uni, &result[o], 3);
if (utflen <= 0)
goto conv_err;
}
result[o] = '\0';
*out_len = o;
befs_debug(sb, "<--- %s", __func__);
return i;
conv_err:
befs_error(sb, "Name using character set %s contains a character that "
"cannot be converted to unicode.", nls->charset);
befs_debug(sb, "<--- %s", __func__);
kfree(result);
return -EILSEQ;
}
static struct inode *befs_nfs_get_inode(struct super_block *sb, uint64_t ino,
uint32_t generation)
{
/* No need to handle i_generation */
return befs_iget(sb, ino);
}
/*
* Map a NFS file handle to a corresponding dentry
*/
static struct dentry *befs_fh_to_dentry(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type)
{
return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
befs_nfs_get_inode);
}
/*
* Find the parent for a file specified by NFS handle
*/
static struct dentry *befs_fh_to_parent(struct super_block *sb,
struct fid *fid, int fh_len, int fh_type)
{
return generic_fh_to_parent(sb, fid, fh_len, fh_type,
befs_nfs_get_inode);
}
static struct dentry *befs_get_parent(struct dentry *child)
{
struct inode *parent;
struct befs_inode_info *befs_ino = BEFS_I(d_inode(child));
parent = befs_iget(child->d_sb,
(unsigned long)befs_ino->i_parent.start);
if (IS_ERR(parent))
return ERR_CAST(parent);
return d_obtain_alias(parent);
}
enum {
Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
};
static const match_table_t befs_tokens = {
{Opt_uid, "uid=%d"},
{Opt_gid, "gid=%d"},
{Opt_charset, "iocharset=%s"},
{Opt_debug, "debug"},
{Opt_err, NULL}
};
static int
parse_options(char *options, struct befs_mount_options *opts)
{
char *p;
substring_t args[MAX_OPT_ARGS];
int option;
kuid_t uid;
kgid_t gid;
/* Initialize options */
opts->uid = GLOBAL_ROOT_UID;
opts->gid = GLOBAL_ROOT_GID;
opts->use_uid = 0;
opts->use_gid = 0;
opts->iocharset = NULL;
opts->debug = 0;
if (!options)
return 1;
while ((p = strsep(&options, ",")) != NULL) {
int token;
if (!*p)
continue;
token = match_token(p, befs_tokens, args);
switch (token) {
case Opt_uid:
if (match_int(&args[0], &option))
return 0;
uid = INVALID_UID;
if (option >= 0)
uid = make_kuid(current_user_ns(), option);
if (!uid_valid(uid)) {
pr_err("Invalid uid %d, "
"using default\n", option);
break;
}
opts->uid = uid;
opts->use_uid = 1;
break;
case Opt_gid:
if (match_int(&args[0], &option))
return 0;
gid = INVALID_GID;
if (option >= 0)
gid = make_kgid(current_user_ns(), option);
if (!gid_valid(gid)) {
pr_err("Invalid gid %d, "
"using default\n", option);
break;
}
opts->gid = gid;
opts->use_gid = 1;
break;
case Opt_charset:
kfree(opts->iocharset);
opts->iocharset = match_strdup(&args[0]);
if (!opts->iocharset) {
pr_err("allocation failure for "
"iocharset string\n");
return 0;
}
break;
case Opt_debug:
opts->debug = 1;
break;
default:
pr_err("Unrecognized mount option \"%s\" "
"or missing value\n", p);
return 0;
}
}
return 1;
}
static int befs_show_options(struct seq_file *m, struct dentry *root)
{
struct befs_sb_info *befs_sb = BEFS_SB(root->d_sb);
struct befs_mount_options *opts = &befs_sb->mount_opts;
if (!uid_eq(opts->uid, GLOBAL_ROOT_UID))
seq_printf(m, ",uid=%u",
from_kuid_munged(&init_user_ns, opts->uid));
if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
seq_printf(m, ",gid=%u",
from_kgid_munged(&init_user_ns, opts->gid));
if (opts->iocharset)
seq_printf(m, ",charset=%s", opts->iocharset);
if (opts->debug)
seq_puts(m, ",debug");
return 0;
}
/* This function has the responsibiltiy of getting the
* filesystem ready for unmounting.
* Basically, we free everything that we allocated in
* befs_read_inode
*/
static void
befs_put_super(struct super_block *sb)
{
kfree(BEFS_SB(sb)->mount_opts.iocharset);
BEFS_SB(sb)->mount_opts.iocharset = NULL;
unload_nls(BEFS_SB(sb)->nls);
kfree(sb->s_fs_info);
sb->s_fs_info = NULL;
}
/* Allocate private field of the superblock, fill it.
*
* Finish filling the public superblock fields
* Make the root directory
* Load a set of NLS translations if needed.
*/
static int
befs_fill_super(struct super_block *sb, void *data, int silent)
{
struct buffer_head *bh;
struct befs_sb_info *befs_sb;
befs_super_block *disk_sb;
struct inode *root;
long ret = -EINVAL;
const unsigned long sb_block = 0;
const off_t x86_sb_off = 512;
int blocksize;
sb->s_fs_info = kzalloc(sizeof(*befs_sb), GFP_KERNEL);
if (sb->s_fs_info == NULL)
goto unacquire_none;
befs_sb = BEFS_SB(sb);
if (!parse_options((char *) data, &befs_sb->mount_opts)) {
if (!silent)
befs_error(sb, "cannot parse mount options");
goto unacquire_priv_sbp;
}
befs_debug(sb, "---> %s", __func__);
if (!sb_rdonly(sb)) {
befs_warning(sb,
"No write support. Marking filesystem read-only");
sb->s_flags |= SB_RDONLY;
}
/*
* Set dummy blocksize to read super block.
* Will be set to real fs blocksize later.
*
* Linux 2.4.10 and later refuse to read blocks smaller than
* the logical block size for the device. But we also need to read at
* least 1k to get the second 512 bytes of the volume.
*/
blocksize = sb_min_blocksize(sb, 1024);
if (!blocksize) {
if (!silent)
befs_error(sb, "unable to set blocksize");
goto unacquire_priv_sbp;
}
bh = sb_bread(sb, sb_block);
if (!bh) {
if (!silent)
befs_error(sb, "unable to read superblock");
goto unacquire_priv_sbp;
}
/* account for offset of super block on x86 */
disk_sb = (befs_super_block *) bh->b_data;
if ((disk_sb->magic1 == BEFS_SUPER_MAGIC1_LE) ||
(disk_sb->magic1 == BEFS_SUPER_MAGIC1_BE)) {
befs_debug(sb, "Using PPC superblock location");
} else {
befs_debug(sb, "Using x86 superblock location");
disk_sb =
(befs_super_block *) ((void *) bh->b_data + x86_sb_off);
}
if ((befs_load_sb(sb, disk_sb) != BEFS_OK) ||
(befs_check_sb(sb) != BEFS_OK))
goto unacquire_bh;
befs_dump_super_block(sb, disk_sb);
brelse(bh);
if (befs_sb->num_blocks > ~((sector_t)0)) {
if (!silent)
befs_error(sb, "blocks count: %llu is larger than the host can use",
befs_sb->num_blocks);
goto unacquire_priv_sbp;
}
/*
* set up enough so that it can read an inode
* Fill in kernel superblock fields from private sb
*/
sb->s_magic = BEFS_SUPER_MAGIC;
/* Set real blocksize of fs */
sb_set_blocksize(sb, (ulong) befs_sb->block_size);
sb->s_op = &befs_sops;
sb->s_export_op = &befs_export_operations;
sb->s_time_min = 0;
sb->s_time_max = 0xffffffffffffll;
root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
if (IS_ERR(root)) {
ret = PTR_ERR(root);
goto unacquire_priv_sbp;
}
sb->s_root = d_make_root(root);
if (!sb->s_root) {
if (!silent)
befs_error(sb, "get root inode failed");
goto unacquire_priv_sbp;
}
/* load nls library */
if (befs_sb->mount_opts.iocharset) {
befs_debug(sb, "Loading nls: %s",
befs_sb->mount_opts.iocharset);
befs_sb->nls = load_nls(befs_sb->mount_opts.iocharset);
if (!befs_sb->nls) {
befs_warning(sb, "Cannot load nls %s"
" loading default nls",
befs_sb->mount_opts.iocharset);
befs_sb->nls = load_nls_default();
}
/* load default nls if none is specified in mount options */
} else {
befs_debug(sb, "Loading default nls");
befs_sb->nls = load_nls_default();
}
return 0;
unacquire_bh:
brelse(bh);
unacquire_priv_sbp:
kfree(befs_sb->mount_opts.iocharset);
kfree(sb->s_fs_info);
sb->s_fs_info = NULL;
unacquire_none:
return ret;
}
static int
befs_remount(struct super_block *sb, int *flags, char *data)
{
sync_filesystem(sb);
if (!(*flags & SB_RDONLY))
return -EINVAL;
return 0;
}
static int
befs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
befs_debug(sb, "---> %s", __func__);
buf->f_type = BEFS_SUPER_MAGIC;
buf->f_bsize = sb->s_blocksize;
buf->f_blocks = BEFS_SB(sb)->num_blocks;
buf->f_bfree = BEFS_SB(sb)->num_blocks - BEFS_SB(sb)->used_blocks;
buf->f_bavail = buf->f_bfree;
buf->f_files = 0; /* UNKNOWN */
buf->f_ffree = 0; /* UNKNOWN */
buf->f_fsid = u64_to_fsid(id);
buf->f_namelen = BEFS_NAME_LEN;
befs_debug(sb, "<--- %s", __func__);
return 0;
}
static struct dentry *
befs_mount(struct file_system_type *fs_type, int flags, const char *dev_name,
void *data)
{
return mount_bdev(fs_type, flags, dev_name, data, befs_fill_super);
}
static struct file_system_type befs_fs_type = {
.owner = THIS_MODULE,
.name = "befs",
.mount = befs_mount,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
MODULE_ALIAS_FS("befs");
static int __init
init_befs_fs(void)
{
int err;
pr_info("version: %s\n", BEFS_VERSION);
err = befs_init_inodecache();
if (err)
goto unacquire_none;
err = register_filesystem(&befs_fs_type);
if (err)
goto unacquire_inodecache;
return 0;
unacquire_inodecache:
befs_destroy_inodecache();
unacquire_none:
return err;
}
static void __exit
exit_befs_fs(void)
{
befs_destroy_inodecache();
unregister_filesystem(&befs_fs_type);
}
/*
* Macros that typecheck the init and exit functions,
* ensures that they are called at init and cleanup,
* and eliminates warnings about unused functions.
*/
module_init(init_befs_fs)
module_exit(exit_befs_fs)