diff options
| -rw-r--r-- | fs/adfs/super.c | 149 |
1 files changed, 78 insertions, 71 deletions
diff --git a/fs/adfs/super.c b/fs/adfs/super.c index 9c93122925cf..4c06b2d5a861 100644 --- a/fs/adfs/super.c +++ b/fs/adfs/super.c @@ -277,13 +277,80 @@ static const struct super_operations adfs_sops = { .show_options = adfs_show_options, }; -static int adfs_fill_super(struct super_block *sb, void *data, int silent) +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; - struct object_info root_obj; + 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; - unsigned int blocksize; + + 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 object_info root_obj; 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; - goto error; } + 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); |