linux/fs/befs/linuxvfs.c

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/*
* linux/fs/befs/linuxvfs.c
*
* Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
*
*/
#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 "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 *, void *, filldir_t);
static int befs_get_block(struct inode *, sector_t, struct buffer_head *, int);
static int befs_readpage(struct file *file, struct page *page);
static sector_t befs_bmap(struct address_space *mapping, sector_t block);
static struct dentry *befs_lookup(struct inode *, struct dentry *, struct nameidata *);
static void befs_read_inode(struct inode *ino);
static struct inode *befs_alloc_inode(struct super_block *sb);
static void befs_destroy_inode(struct inode *inode);
static int befs_init_inodecache(void);
static void befs_destroy_inodecache(void);
static void *befs_follow_link(struct dentry *, struct nameidata *);
static void befs_put_link(struct dentry *, struct nameidata *, void *);
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 parse_options(char *, befs_mount_options *);
static const struct super_operations befs_sops = {
.read_inode = befs_read_inode, /* initialize & read inode */
.alloc_inode = befs_alloc_inode, /* allocate a new inode */
.destroy_inode = befs_destroy_inode, /* deallocate an inode */
.put_super = befs_put_super, /* uninit super */
.statfs = befs_statfs, /* statfs */
.remount_fs = befs_remount,
};
/* 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,
.readdir = befs_readdir,
};
static struct inode_operations befs_dir_inode_operations = {
.lookup = befs_lookup,
};
static const struct address_space_operations befs_aops = {
.readpage = befs_readpage,
.sync_page = block_sync_page,
.bmap = befs_bmap,
};
static struct inode_operations befs_symlink_inode_operations = {
.readlink = generic_readlink,
.follow_link = befs_follow_link,
.put_link = befs_put_link,
};
/*
* Called by generic_file_read() to read a page 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_readpage(struct file *file, struct page *page)
{
return block_read_full_page(page, 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.
*
* -WD 10-26-01
*/
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 = 0;
ulong disk_off;
befs_debug(sb, "---> befs_get_block() for inode %lu, block %ld",
inode->i_ino, block);
if (block < 0) {
befs_error(sb, "befs_get_block() was asked for a block "
"number less than zero: block %ld in inode %lu",
block, inode->i_ino);
return -EIO;
}
if (create) {
befs_error(sb, "befs_get_block() was asked to write to "
"block %ld in inode %lu", block, inode->i_ino);
return -EPERM;
}
res = befs_fblock2brun(sb, ds, block, &run);
if (res != BEFS_OK) {
befs_error(sb,
"<--- befs_get_block() for inode %lu, block "
"%ld ERROR", inode->i_ino, block);
return -EFBIG;
}
disk_off = (ulong) iaddr2blockno(sb, &run);
map_bh(bh_result, inode->i_sb, disk_off);
befs_debug(sb, "<--- befs_get_block() for inode %lu, block %ld, "
"disk address %lu", inode->i_ino, block, disk_off);
return 0;
}
static struct dentry *
befs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
struct inode *inode = NULL;
struct super_block *sb = dir->i_sb;
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, "---> befs_lookup() "
"name %s inode %ld", dentry->d_name.name, 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, "<--- befs_lookup() ERROR");
return ERR_PTR(ret);
}
ret = befs_btree_find(sb, ds, utfname, &offset);
kfree(utfname);
} else {
ret = befs_btree_find(sb, ds, dentry->d_name.name, &offset);
}
if (ret == BEFS_BT_NOT_FOUND) {
befs_debug(sb, "<--- befs_lookup() %s not found",
dentry->d_name.name);
return ERR_PTR(-ENOENT);
} else if (ret != BEFS_OK || offset == 0) {
befs_warning(sb, "<--- befs_lookup() Error");
return ERR_PTR(-ENODATA);
}
inode = iget(dir->i_sb, (ino_t) offset);
if (!inode)
return ERR_PTR(-EACCES);
d_add(dentry, inode);
befs_debug(sb, "<--- befs_lookup()");
return NULL;
}
static int
befs_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
struct inode *inode = filp->f_dentry->d_inode;
struct super_block *sb = inode->i_sb;
befs_data_stream *ds = &BEFS_I(inode)->i_data.ds;
befs_off_t value;
int result;
size_t keysize;
unsigned char d_type;
char keybuf[BEFS_NAME_LEN + 1];
char *nlsname;
int nlsnamelen;
const char *dirname = filp->f_dentry->d_name.name;
befs_debug(sb, "---> befs_readdir() "
"name %s, inode %ld, filp->f_pos %Ld",
dirname, inode->i_ino, filp->f_pos);
result = befs_btree_read(sb, ds, filp->f_pos, BEFS_NAME_LEN + 1,
keybuf, &keysize, &value);
if (result == BEFS_ERR) {
befs_debug(sb, "<--- befs_readdir() ERROR");
befs_error(sb, "IO error reading %s (inode %lu)",
dirname, inode->i_ino);
return -EIO;
} else if (result == BEFS_BT_END) {
befs_debug(sb, "<--- befs_readdir() END");
return 0;
} else if (result == BEFS_BT_EMPTY) {
befs_debug(sb, "<--- befs_readdir() Empty directory");
return 0;
}
d_type = DT_UNKNOWN;
/* Convert to NLS */
if (BEFS_SB(sb)->nls) {
result =
befs_utf2nls(sb, keybuf, keysize, &nlsname, &nlsnamelen);
if (result < 0) {
befs_debug(sb, "<--- befs_readdir() ERROR");
return result;
}
result = filldir(dirent, nlsname, nlsnamelen, filp->f_pos,
(ino_t) value, d_type);
kfree(nlsname);
} else {
result = filldir(dirent, keybuf, keysize, filp->f_pos,
(ino_t) value, d_type);
}
filp->f_pos++;
befs_debug(sb, "<--- befs_readdir() filp->f_pos %Ld", filp->f_pos);
return 0;
}
static struct inode *
befs_alloc_inode(struct super_block *sb)
{
struct befs_inode_info *bi;
bi = (struct befs_inode_info *)kmem_cache_alloc(befs_inode_cachep,
GFP_KERNEL);
if (!bi)
return NULL;
return &bi->vfs_inode;
}
static void
befs_destroy_inode(struct inode *inode)
{
kmem_cache_free(befs_inode_cachep, BEFS_I(inode));
}
static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
{
struct befs_inode_info *bi = (struct befs_inode_info *) foo;
if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
SLAB_CTOR_CONSTRUCTOR) {
inode_init_once(&bi->vfs_inode);
}
}
static void
befs_read_inode(struct inode *inode)
{
struct buffer_head *bh = NULL;
befs_inode *raw_inode = NULL;
struct super_block *sb = inode->i_sb;
befs_sb_info *befs_sb = BEFS_SB(sb);
befs_inode_info *befs_ino = NULL;
befs_debug(sb, "---> befs_read_inode() " "inode = %lu", inode->i_ino);
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 = befs_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 : (uid_t) fs32_to_cpu(sb, raw_inode->uid);
inode->i_gid = befs_sb->mount_opts.use_gid ?
befs_sb->mount_opts.gid : (gid_t) fs32_to_cpu(sb, raw_inode->gid);
inode->i_nlink = 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->i_mtime.tv_sec =
fs64_to_cpu(sb, raw_inode->last_modified_time) >> 16;
inode->i_mtime.tv_nsec = 0; /* lower 16 bits are not a time */
inode->i_ctime = inode->i_mtime;
inode->i_atime = inode->i_mtime;
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;
strncpy(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)) {
inode->i_op = &befs_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, "<--- befs_read_inode()");
return;
unacquire_bh:
brelse(bh);
unacquire_none:
make_bad_inode(inode);
befs_debug(sb, "<--- befs_read_inode() - Bad inode");
return;
}
/* Initialize the inode cache. Called at fs setup.
*
* Taken from NFS implementation by Al Viro.
*/
static int
befs_init_inodecache(void)
{
befs_inode_cachep = kmem_cache_create("befs_inode_cache",
sizeof (struct befs_inode_info),
0, (SLAB_RECLAIM_ACCOUNT|
SLAB_MEM_SPREAD),
init_once, NULL);
if (befs_inode_cachep == NULL) {
printk(KERN_ERR "befs_init_inodecache: "
"Couldn't initalize inode slabcache\n");
return -ENOMEM;
}
return 0;
}
/* Called at fs teardown.
*
* Taken from NFS implementation by Al Viro.
*/
static void
befs_destroy_inodecache(void)
{
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 void *
befs_follow_link(struct dentry *dentry, struct nameidata *nd)
{
befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
char *link;
if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
struct super_block *sb = dentry->d_sb;
befs_data_stream *data = &befs_ino->i_data.ds;
befs_off_t len = data->size;
befs_debug(sb, "Follow long symlink");
link = kmalloc(len, GFP_NOFS);
if (!link) {
link = ERR_PTR(-ENOMEM);
} else if (befs_read_lsymlink(sb, data, link, len) != len) {
kfree(link);
befs_error(sb, "Failed to read entire long symlink");
link = ERR_PTR(-EIO);
}
} else {
link = befs_ino->i_data.symlink;
}
nd_set_link(nd, link);
return NULL;
}
static void befs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
{
befs_inode_info *befs_ino = BEFS_I(dentry->d_inode);
if (befs_ino->i_flags & BEFS_LONG_SYMLINK) {
char *p = nd_get_link(nd);
if (!IS_ERR(p))
kfree(p);
}
}
/*
* UTF-8 to NLS charset convert routine
*
*
* Changed 8/10/01 by Will Dyson. Now use 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;
wchar_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, "---> utf2nls()");
if (!nls) {
befs_error(sb, "befs_utf2nls called with no NLS table loaded");
return -EINVAL;
}
*out = result = kmalloc(maxlen, GFP_NOFS);
if (!*out) {
befs_error(sb, "befs_utf2nls() cannot allocate memory");
*out_len = 0;
return -ENOMEM;
}
for (i = o = 0; i < in_len; i += utflen, o += unilen) {
/* convert from UTF-8 to Unicode */
utflen = utf8_mbtowc(&uni, &in[i], in_len - i);
if (utflen < 0) {
goto conv_err;
}
/* convert from Unicode to nls */
unilen = nls->uni2char(uni, &result[o], in_len - o);
if (unilen < 0) {
goto conv_err;
}
}
result[o] = '\0';
*out_len = o;
befs_debug(sb, "<--- utf2nls()");
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, "<--- utf2nls()");
kfree(result);
return -EILSEQ;
}
/**
* befs_nls2utf - Convert NLS string to utf8 encodeing
* @sb: Superblock
* @src: Input string buffer in NLS format
* @srclen: Length of input string in bytes
* @dest: The output string in UTF-8 format
* @destlen: Length of the output buffer
*
* Converts input string @src, which is in the format of the loaded NLS map,
* into a utf8 string.
*
* The destination string @dest is allocated by this function and the caller is
* responsible for freeing it with kfree()
*
* On return, *@destlen is the length of @dest in bytes.
*
* On success, the return value is the number of utf8 characters written to
* the output buffer @dest.
*
* 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're nls characters that will translate to 3-chars-wide UTF-8
* characters, a additional byte is needed to save the final \0
* in special cases */
int maxlen = (3 * in_len) + 1;
befs_debug(sb, "---> nls2utf()\n");
if (!nls) {
befs_error(sb, "befs_nls2utf called with no NLS table loaded.");
return -EINVAL;
}
*out = result = kmalloc(maxlen, GFP_NOFS);
if (!*out) {
befs_error(sb, "befs_nls2utf() cannot allocate memory");
*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 = utf8_wctomb(&result[o], uni, 3);
if (utflen <= 0) {
goto conv_err;
}
}
result[o] = '\0';
*out_len = o;
befs_debug(sb, "<--- nls2utf()");
return i;
conv_err:
befs_error(sb, "Name using charecter set %s contains a charecter that "
"cannot be converted to unicode.", nls->charset);
befs_debug(sb, "<--- nls2utf()");
kfree(result);
return -EILSEQ;
}
/**
* Use the
*
*/
enum {
Opt_uid, Opt_gid, Opt_charset, Opt_debug, Opt_err,
};
static 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, befs_mount_options * opts)
{
char *p;
substring_t args[MAX_OPT_ARGS];
int option;
/* Initialize options */
opts->uid = 0;
opts->gid = 0;
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;
if (option < 0) {
printk(KERN_ERR "BeFS: Invalid uid %d, "
"using default\n", option);
break;
}
opts->uid = option;
opts->use_uid = 1;
break;
case Opt_gid:
if (match_int(&args[0], &option))
return 0;
if (option < 0) {
printk(KERN_ERR "BeFS: Invalid gid %d, "
"using default\n", option);
break;
}
opts->gid = option;
opts->use_gid = 1;
break;
case Opt_charset:
kfree(opts->iocharset);
opts->iocharset = match_strdup(&args[0]);
if (!opts->iocharset) {
printk(KERN_ERR "BeFS: allocation failure for "
"iocharset string\n");
return 0;
}
break;
case Opt_debug:
opts->debug = 1;
break;
default:
printk(KERN_ERR "BeFS: Unrecognized mount option \"%s\" "
"or missing value\n", p);
return 0;
}
}
return 1;
}
/* This function has the responsibiltiy of getting the
* filesystem ready for unmounting.
* Basicly, 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;
if (BEFS_SB(sb)->nls) {
unload_nls(BEFS_SB(sb)->nls);
BEFS_SB(sb)->nls = NULL;
}
kfree(sb->s_fs_info);
sb->s_fs_info = NULL;
return;
}
/* 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;
befs_sb_info *befs_sb;
befs_super_block *disk_sb;
struct inode *root;
const unsigned long sb_block = 0;
const off_t x86_sb_off = 512;
sb->s_fs_info = kmalloc(sizeof (*befs_sb), GFP_KERNEL);
if (sb->s_fs_info == NULL) {
printk(KERN_ERR
"BeFS(%s): Unable to allocate memory for private "
"portion of superblock. Bailing.\n", sb->s_id);
goto unacquire_none;
}
befs_sb = BEFS_SB(sb);
memset(befs_sb, 0, sizeof(befs_sb_info));
if (!parse_options((char *) data, &befs_sb->mount_opts)) {
befs_error(sb, "cannot parse mount options");
goto unacquire_priv_sbp;
}
befs_debug(sb, "---> befs_fill_super()");
#ifndef CONFIG_BEFS_RW
if (!(sb->s_flags & MS_RDONLY)) {
befs_warning(sb,
"No write support. Marking filesystem read-only");
sb->s_flags |= MS_RDONLY;
}
#endif /* CONFIG_BEFS_RW */
/*
* 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 hardsect size for the device. But we also need to read at
* least 1k to get the second 512 bytes of the volume.
* -WD 10-26-01
*/
sb_min_blocksize(sb, 1024);
if (!(bh = sb_bread(sb, sb_block))) {
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 ((le32_to_cpu(disk_sb->magic1) == BEFS_SUPER_MAGIC1) ||
(be32_to_cpu(disk_sb->magic1) == BEFS_SUPER_MAGIC1)) {
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)
goto unacquire_bh;
befs_dump_super_block(sb, disk_sb);
brelse(bh);
if (befs_check_sb(sb) != BEFS_OK)
goto unacquire_priv_sbp;
if( befs_sb->num_blocks > ~((sector_t)0) ) {
befs_error(sb, "blocks count: %Lu "
"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 = (struct super_operations *) &befs_sops;
root = iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
sb->s_root = d_alloc_root(root);
if (!sb->s_root) {
iput(root);
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(sb->s_fs_info);
unacquire_none:
sb->s_fs_info = NULL;
return -EINVAL;
}
static int
befs_remount(struct super_block *sb, int *flags, char *data)
{
if (!(*flags & MS_RDONLY))
return -EINVAL;
return 0;
}
static int
befs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
befs_debug(sb, "---> befs_statfs()");
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_namelen = BEFS_NAME_LEN;
befs_debug(sb, "<--- befs_statfs()");
return 0;
}
[PATCH] VFS: Permit filesystem to override root dentry on mount Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 09:02:57 +00:00
static int
befs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name,
[PATCH] VFS: Permit filesystem to override root dentry on mount Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 09:02:57 +00:00
void *data, struct vfsmount *mnt)
{
[PATCH] VFS: Permit filesystem to override root dentry on mount Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 09:02:57 +00:00
return get_sb_bdev(fs_type, flags, dev_name, data, befs_fill_super,
mnt);
}
static struct file_system_type befs_fs_type = {
.owner = THIS_MODULE,
.name = "befs",
.get_sb = befs_get_sb,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
static int __init
init_befs_fs(void)
{
int err;
printk(KERN_INFO "BeFS 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)