/*
* fill in the superblock
*/
static int romfs_fill_super(struct super_block *sb, void *data, int silent)
{
struct romfs_super_block *rsb;
struct inode *root;
unsigned long pos, img_size;
const char *storage;
size_t len;
int ret;
#ifdef CONFIG_BLOCK
if (!sb->s_mtd) {
sb_set_blocksize(sb, ROMBSIZE);
} else {
sb->s_blocksize = ROMBSIZE;
sb->s_blocksize_bits = blksize_bits(ROMBSIZE);
}
#endif
sb->s_maxbytes = 0xFFFFFFFF;
sb->s_magic = ROMFS_MAGIC;
sb->s_flags |= MS_RDONLY | MS_NOATIME;
sb->s_op = &romfs_super_ops;
/* read the image superblock and check it */
rsb = kmalloc(512, GFP_KERNEL);
if (!rsb)
return -ENOMEM;
sb->s_fs_info = (void *) 512;
ret = romfs_dev_read(sb, 0, rsb, 512);
if (ret < 0)
goto error_rsb;
img_size = be32_to_cpu(rsb->size);
if (sb->s_mtd && img_size > sb->s_mtd->size)
goto error_rsb_inval;
sb->s_fs_info = (void *) img_size;
if (rsb->word0 != ROMSB_WORD0 || rsb->word1 != ROMSB_WORD1 ||
img_size < ROMFH_SIZE) {
if (!silent)
printk(KERN_WARNING "VFS:"
" Can't find a romfs filesystem on dev %s.\n",
sb->s_id);
goto error_rsb_inval;
}
if (romfs_checksum(rsb, min_t(size_t, img_size, 512))) {
printk(KERN_ERR "ROMFS: bad initial checksum on dev %s.\n",
sb->s_id);
goto error_rsb_inval;
}
storage = sb->s_mtd ? "MTD" : "the block layer";
len = strnlen(rsb->name, ROMFS_MAXFN);
if (!silent)
printk(KERN_NOTICE "ROMFS: Mounting image '%*.*s' through %s\n",
(unsigned) len, (unsigned) len, rsb->name, storage);
kfree(rsb);
rsb = NULL;
/* find the root directory */
pos = (ROMFH_SIZE + len + 1 + ROMFH_PAD) & ROMFH_MASK;
root = romfs_iget(sb, pos);
if (IS_ERR(root))
goto error;
sb->s_root = d_alloc_root(root);
if (!sb->s_root)
goto error_i;
return 0;
error_i:
iput(root);
error:
return -EINVAL;
error_rsb_inval:
ret = -EINVAL;
error_rsb:
kfree(rsb);
return ret;
}
static struct dentry *
romfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
unsigned long offset, maxoff;
long res;
int fslen;
struct inode *inode = NULL;
char fsname[ROMFS_MAXFN]; /* XXX dynamic? */
struct romfs_inode ri;
const char *name; /* got from dentry */
int len;
res = -EACCES; /* placeholder for "no data here" */
offset = dir->i_ino & ROMFH_MASK;
lock_kernel();
if (romfs_copyfrom(dir, &ri, offset, ROMFH_SIZE) <= 0)
goto error;
maxoff = romfs_maxsize(dir->i_sb);
offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
/* OK, now find the file whose name is in "dentry" in the
* directory specified by "dir". */
name = dentry->d_name.name;
len = dentry->d_name.len;
for(;;) {
if (!offset || offset >= maxoff)
goto success; /* negative success */
if (romfs_copyfrom(dir, &ri, offset, ROMFH_SIZE) <= 0)
goto error;
/* try to match the first 16 bytes of name */
fslen = romfs_strnlen(dir, offset+ROMFH_SIZE, ROMFH_SIZE);
if (len < ROMFH_SIZE) {
if (len == fslen) {
/* both are shorter, and same size */
romfs_copyfrom(dir, fsname, offset+ROMFH_SIZE, len+1);
if (strncmp (name, fsname, len) == 0)
break;
}
} else if (fslen >= ROMFH_SIZE) {
/* both are longer; XXX optimize max size */
fslen = romfs_strnlen(dir, offset+ROMFH_SIZE, sizeof(fsname)-1);
if (len == fslen) {
romfs_copyfrom(dir, fsname, offset+ROMFH_SIZE, len+1);
if (strncmp(name, fsname, len) == 0)
break;
}
}
/* next entry */
offset = be32_to_cpu(ri.next) & ROMFH_MASK;
}
/* Hard link handling */
if ((be32_to_cpu(ri.next) & ROMFH_TYPE) == ROMFH_HRD)
offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
inode = romfs_iget(dir->i_sb, offset);
if (IS_ERR(inode)) {
res = PTR_ERR(inode);
goto error;
}
success:
d_add(dentry, inode);
res = 0;
error:
unlock_kernel();
return ERR_PTR(res);
}
/*
* look up an entry in a directory
*/
static struct dentry *romfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
unsigned long offset, maxoff;
struct inode *inode;
struct romfs_inode ri;
const char *name; /* got from dentry */
int len, ret;
offset = dir->i_ino & ROMFH_MASK;
ret = romfs_dev_read(dir->i_sb, offset, &ri, ROMFH_SIZE);
if (ret < 0)
goto error;
/* search all the file entries in the list starting from the one
* pointed to by the directory's special data */
maxoff = romfs_maxsize(dir->i_sb);
offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
name = dentry->d_name.name;
len = dentry->d_name.len;
for (;;) {
if (!offset || offset >= maxoff)
goto out0;
ret = romfs_dev_read(dir->i_sb, offset, &ri, sizeof(ri));
if (ret < 0)
goto error;
/* try to match the first 16 bytes of name */
ret = romfs_dev_strcmp(dir->i_sb, offset + ROMFH_SIZE, name,
len);
if (ret < 0)
goto error;
if (ret == 1)
break;
/* next entry */
offset = be32_to_cpu(ri.next) & ROMFH_MASK;
}
/* Hard link handling */
if ((be32_to_cpu(ri.next) & ROMFH_TYPE) == ROMFH_HRD)
offset = be32_to_cpu(ri.spec) & ROMFH_MASK;
inode = romfs_iget(dir->i_sb, offset);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
goto error;
}
goto outi;
/*
* it's a bit funky, _lookup needs to return an error code
* (negative) or a NULL, both as a dentry. ENOENT should not
* be returned, instead we need to create a negative dentry by
* d_add(dentry, NULL); and return 0 as no error.
* (Although as I see, it only matters on writable file
* systems).
*/
out0:
inode = NULL;
outi:
d_add(dentry, inode);
ret = 0;
error:
return ERR_PTR(ret);
}
static int romfs_fill_super(struct super_block *s, void *data, int silent)
{
struct buffer_head *bh;
struct romfs_super_block *rsb;
struct inode *root;
int sz, ret = -EINVAL;
/* I would parse the options here, but there are none.. :) */
sb_set_blocksize(s, ROMBSIZE);
s->s_maxbytes = 0xFFFFFFFF;
bh = sb_bread(s, 0);
if (!bh) {
/* XXX merge with other printk? */
printk ("romfs: unable to read superblock\n");
goto outnobh;
}
rsb = (struct romfs_super_block *)bh->b_data;
sz = be32_to_cpu(rsb->size);
if (rsb->word0 != ROMSB_WORD0 || rsb->word1 != ROMSB_WORD1
|| sz < ROMFH_SIZE) {
if (!silent)
printk ("VFS: Can't find a romfs filesystem on dev "
"%s.\n", s->s_id);
goto out;
}
if (romfs_checksum(rsb, min_t(int, sz, 512))) {
printk ("romfs: bad initial checksum on dev "
"%s.\n", s->s_id);
goto out;
}
s->s_magic = ROMFS_MAGIC;
s->s_fs_info = (void *)(long)sz;
s->s_flags |= MS_RDONLY;
/* Find the start of the fs */
sz = (ROMFH_SIZE +
strnlen(rsb->name, ROMFS_MAXFN) + 1 + ROMFH_PAD)
& ROMFH_MASK;
s->s_op = &romfs_ops;
root = romfs_iget(s, sz);
if (IS_ERR(root)) {
ret = PTR_ERR(root);
goto out;
}
ret = -ENOMEM;
s->s_root = d_alloc_root(root);
if (!s->s_root)
goto outiput;
brelse(bh);
return 0;
outiput:
iput(root);
out:
brelse(bh);
outnobh:
return ret;
}
