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@xxxxxxxxxxxxxxx>
---
fs/adfs/super.c | 149 +++++++++++++++++++++++++-----------------------
1 file 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);
--
2.20.1
