korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-23 20:24:12 +08:00
Code Issues Packages Projects Releases Wiki Activity

fs/adfs: super: extract filesystem block probe

Browse Source 
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 2019-12-09 11:11:28 +00:00 committed by Al Viro
parent ccbc80a89d
commit e3858e125b
1 changed files with 78 additions and 71 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

149
fs/adfs/super.c
View File

@ -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);