fs/adfs: super: extract filesystem block probe
Separate the filesystem block probing from the superblock filling so we can support other ADFS filesystem formats, such as the single-zone E and E+ floppy image formats which do not have a boot block. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Russell King
Al Viro
Родитель
ccbc80a89d
Коммит
e3858e125b
149
fs/adfs/super.c
149
fs/adfs/super.c
|
|
@ -277,13 +277,80 @@ static const struct super_operations adfs_sops = {
|
|||
.show_options = adfs_show_options,
|
||||
};
|
||||
|
||||
static int adfs_probe(struct super_block *sb, unsigned int offset, int silent,
|
||||
int (*validate)(struct super_block *sb,
|
||||
struct buffer_head *bh,
|
||||
struct adfs_discrecord **bhp))
|
||||
{
|
||||
struct adfs_sb_info *asb = ADFS_SB(sb);
|
||||
struct adfs_discrecord *dr;
|
||||
struct buffer_head *bh;
|
||||
unsigned int blocksize = BLOCK_SIZE;
|
||||
int ret, try;
|
||||
|
||||
for (try = 0; try < 2; try++) {
|
||||
/* try to set the requested block size */
|
||||
if (sb->s_blocksize != blocksize &&
|
||||
!sb_set_blocksize(sb, blocksize)) {
|
||||
if (!silent)
|
||||
adfs_msg(sb, KERN_ERR,
|
||||
"error: unsupported blocksize");
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
/* read the buffer */
|
||||
bh = sb_bread(sb, offset >> sb->s_blocksize_bits);
|
||||
if (!bh) {
|
||||
adfs_msg(sb, KERN_ERR,
|
||||
"error: unable to read block %u, try %d",
|
||||
offset >> sb->s_blocksize_bits, try);
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
/* validate it */
|
||||
ret = validate(sb, bh, &dr);
|
||||
if (ret) {
|
||||
brelse(bh);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/* does the block size match the filesystem block size? */
|
||||
blocksize = 1 << dr->log2secsize;
|
||||
if (sb->s_blocksize == blocksize) {
|
||||
asb->s_map = adfs_read_map(sb, dr);
|
||||
brelse(bh);
|
||||
return PTR_ERR_OR_ZERO(asb->s_map);
|
||||
}
|
||||
|
||||
brelse(bh);
|
||||
}
|
||||
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
static int adfs_validate_bblk(struct super_block *sb, struct buffer_head *bh,
|
||||
struct adfs_discrecord **drp)
|
||||
{
|
||||
struct adfs_discrecord *dr;
|
||||
unsigned char *b_data;
|
||||
|
||||
b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
|
||||
if (adfs_checkbblk(b_data))
|
||||
return -EILSEQ;
|
||||
|
||||
/* Do some sanity checks on the ADFS disc record */
|
||||
dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
|
||||
if (adfs_checkdiscrecord(dr))
|
||||
return -EILSEQ;
|
||||
|
||||
*drp = dr;
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int adfs_fill_super(struct super_block *sb, void *data, int silent)
|
||||
{
|
||||
struct adfs_discrecord *dr;
|
||||
struct buffer_head *bh;
|
||||
struct object_info root_obj;
|
||||
unsigned char *b_data;
|
||||
unsigned int blocksize;
|
||||
struct adfs_sb_info *asb;
|
||||
struct inode *root;
|
||||
int ret = -EINVAL;
|
||||
|
|
@ -308,72 +375,19 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent)
|
|||
if (parse_options(sb, asb, data))
|
||||
goto error;
|
||||
|
||||
sb_set_blocksize(sb, BLOCK_SIZE);
|
||||
if (!(bh = sb_bread(sb, ADFS_DISCRECORD / BLOCK_SIZE))) {
|
||||
adfs_msg(sb, KERN_ERR, "error: unable to read superblock");
|
||||
ret = -EIO;
|
||||
goto error;
|
||||
}
|
||||
|
||||
b_data = bh->b_data + (ADFS_DISCRECORD % BLOCK_SIZE);
|
||||
|
||||
if (adfs_checkbblk(b_data)) {
|
||||
ret = -EINVAL;
|
||||
goto error_badfs;
|
||||
}
|
||||
|
||||
dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
|
||||
|
||||
/*
|
||||
* Do some sanity checks on the ADFS disc record
|
||||
*/
|
||||
if (adfs_checkdiscrecord(dr)) {
|
||||
ret = -EINVAL;
|
||||
goto error_badfs;
|
||||
}
|
||||
|
||||
blocksize = 1 << dr->log2secsize;
|
||||
brelse(bh);
|
||||
|
||||
if (sb_set_blocksize(sb, blocksize)) {
|
||||
bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
|
||||
if (!bh) {
|
||||
adfs_msg(sb, KERN_ERR,
|
||||
"error: couldn't read superblock on 2nd try.");
|
||||
ret = -EIO;
|
||||
goto error;
|
||||
}
|
||||
b_data = bh->b_data + (ADFS_DISCRECORD % sb->s_blocksize);
|
||||
if (adfs_checkbblk(b_data)) {
|
||||
adfs_msg(sb, KERN_ERR,
|
||||
"error: disc record mismatch, very weird!");
|
||||
ret = -EINVAL;
|
||||
goto error_free_bh;
|
||||
}
|
||||
dr = (struct adfs_discrecord *)(b_data + ADFS_DR_OFFSET);
|
||||
} else {
|
||||
/* Try to probe the filesystem boot block */
|
||||
ret = adfs_probe(sb, ADFS_DISCRECORD, silent, adfs_validate_bblk);
|
||||
if (ret == -EILSEQ) {
|
||||
if (!silent)
|
||||
adfs_msg(sb, KERN_ERR,
|
||||
"error: unsupported blocksize");
|
||||
"error: can't find an ADFS filesystem on dev %s.",
|
||||
sb->s_id);
|
||||
ret = -EINVAL;
|
||||
}
|
||||
if (ret)
|
||||
goto error;
|
||||
}
|
||||
|
||||
/*
|
||||
* blocksize on this device should now be set to the ADFS log2secsize
|
||||
*/
|
||||
|
||||
asb->s_map = adfs_read_map(sb, dr);
|
||||
if (IS_ERR(asb->s_map)) {
|
||||
ret = PTR_ERR(asb->s_map);
|
||||
goto error_free_bh;
|
||||
}
|
||||
|
||||
brelse(bh);
|
||||
|
||||
/*
|
||||
* set up enough so that we can read an inode
|
||||
*/
|
||||
/* set up enough so that we can read an inode */
|
||||
sb->s_op = &adfs_sops;
|
||||
|
||||
dr = adfs_map_discrecord(asb->s_map);
|
||||
|
|
@ -417,13 +431,6 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent)
|
|||
}
|
||||
return 0;
|
||||
|
||||
error_badfs:
|
||||
if (!silent)
|
||||
adfs_msg(sb, KERN_ERR,
|
||||
"error: can't find an ADFS filesystem on dev %s.",
|
||||
sb->s_id);
|
||||
error_free_bh:
|
||||
brelse(bh);
|
||||
error:
|
||||
sb->s_fs_info = NULL;
|
||||
kfree(asb);
|
||||
|
|
|
|||
Загрузка…
Ссылка в новой задаче