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MO-Drive under 2.4.7 usinf vfat

DISCUSSION Douglas Gilbert 4 participants 6 messages Jul 22, 2001 – Jul 25, 2001

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Douglas Gilbert

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#0 lore raw
Quoted 1 line · OGAWA Hirofumi

Is the capacity of your MO disk more than 640M?

No, the capacity is 635600896 bytes.

$ sg_readcap /dev/sg1
Read Capacity results:
   Last block address = 310351 (0x4bc4f), Number of blocks = 310352
   Block size = 2048 bytes

This is from my log:
Attached scsi removable disk sdb at scsi4, channel 0, id 0, lun 0 SCSI device sdb: 310352 2048-byte hdwr sectors (636 MB)

$ cat /proc/scsi/scsi 
Attached devices: 
Host: scsi1 Channel: 00 Id: 01 Lun: 00
  Vendor: IBM      Model: DNES-309170W     Rev: SA30
  Type:   Direct-Access                    ANSI SCSI revision: 03
Host: scsi4 Channel: 00 Id: 00 Lun: 00
  Vendor: FUJITSU  Model: M25-MCC3064AP    Rev: 0023
  Type:   Optical Device                   ANSI SCSI revision: 02

On my box the MO drive is /dev/sdb or /dev/sg1 .

Executing 'mount -t vfat /dev/sdb /mnt/extra -o debug' put this in my log:
MSDOS: Hardware sector size is 2048
[MS-DOS FS Rel. 12,FAT 16,check=n,conv=b,uid=0,gid=0,umask=022] [me=0xf8,cs=32,#f=2,fs=1,fl=152,ds=305,de=512,data=
337,se=0,ts=1241408,ls=512,rc=0,fc=4294967295]
Transaction block size = 2048

Quoted 2 lines

Perhaps, your MO disk will have the `ls' of a value smaller than 2048.

Yes, ls=512 .

Quoted 2 lines

Logical sector size smaller than device sector size cannot be handled with FAT of 2.4 series.

Great. When will that be fixed (Jens?) ? If not, can we get a more civilized response than the current oops?

Doug Gilbert

#1 lore raw

Hi,

Quoted 4 lines · Douglas Gilbert
Quoted 1 line · OGAWA Hirofumi

Is the capacity of your MO disk more than 640M?

No, the capacity is 635600896 bytes.

[...]

Quoted 10 lines
Quoted 3 lines

Perhaps, your MO disk will have the `ls' of a value smaller than 2048.

Yes, ls=512 .

Quoted 2 lines

Logical sector size smaller than device sector size cannot be handled with FAT of 2.4 series.

Great. When will that be fixed (Jens?) ? If not, can we get a more civilized response than the current oops?

The cause of this problem is me, and I think that it is the bug. How should this problem be solved? I think that it is either of the following.

1) logical sector size smaller than device sector size isn't supported. (and output the message)

2) read a file data via block buffer (like FAT of 2.2 series).

3) other (drivers/block/loop.c?)

Please comment.

Signature · 1 line
OGAWA Hirofumi <[email protected]>
#2 lore raw
In reply to Douglas Gilbert
Quoted 5 lines · Douglas Gilbert
Quoted 2 lines

Logical sector size smaller than device sector size cannot be handled with FAT of 2.4 series.

Great. When will that be fixed (Jens?) ? If not, can we get a more civilized response than the current oops?

FAT oopses, right?

It will not be fixed (Logical sector size smaller than device sector size) directly, there needs to be support for this type of thing. For now folks should just use loop on top of DVD-RAM, for instance.

Signature · 1 line
Jens Axboe
#3 lore raw
Quoted 5 lines

FAT oopses, right?

It will not be fixed (Logical sector size smaller than device sector size) directly, there needs to be support for this type of thing. For now folks should just use loop on top of DVD-RAM, for instance.

Oopses are bad. It means any random user can trick you into crashing your box just by swapping media around or you crash it in error

I/O error by all means - but oops is a bug

#4 lore raw
Quoted 11 lines · Alan Cox
Quoted 5 lines

FAT oopses, right?

It will not be fixed (Logical sector size smaller than device sector size) directly, there needs to be support for this type of thing. For now folks should just use loop on top of DVD-RAM, for instance.

Oopses are bad. It means any random user can trick you into crashing your box just by swapping media around or you crash it in error

I/O error by all means - but oops is a bug

Yes, I agree.

I finished now writing and testing the following patch which fixed oops and some messages.

Please apply.

Signature · 335 lines
OGAWA Hirofumi <[email protected]>

diff -urN linux-2.4.7/fs/fat/buffer.c fat-2.4.7/fs/fat/buffer.c
--- linux-2.4.7/fs/fat/buffer.c	Fri May 25 07:36:33 2001
+++ fat-2.4.7/fs/fat/buffer.c	Wed Jul 25 00:39:23 2001
@@ -100,62 +100,3 @@
 {
 	ll_rw_block(opr,nbreq,bh);
 }
-
-struct buffer_head *bigblock_fat_bread(struct super_block *sb, int block)
-{
-	unsigned int hardsect = get_hardsect_size(sb->s_dev);
-	int rblock, roffset;
-	struct buffer_head *real, *dummy;
-
-	if (hardsect <= sb->s_blocksize)
-		BUG();
-
-	dummy = NULL;
-	rblock = block / (hardsect / sb->s_blocksize);
-	roffset = (block % (hardsect / sb->s_blocksize)) * sb->s_blocksize;
-	real = bread(sb->s_dev, rblock, hardsect);
-	if (real != NULL) {
-		dummy = kmalloc(sizeof(struct buffer_head), GFP_KERNEL);
-		if (dummy != NULL) {
-			memset(dummy, 0, sizeof(*dummy));
-			dummy->b_data = real->b_data + roffset;
-			dummy->b_next = real;
-		} else
-			brelse(real);
-	}
-
-	return dummy;
-}
-
-void bigblock_fat_brelse(struct super_block *sb, struct buffer_head *bh)
-{
-	brelse(bh->b_next);
-	kfree(bh);
-}
-
-void bigblock_fat_mark_buffer_dirty(struct super_block *sb, struct buffer_head *bh)
-{
-	mark_buffer_dirty(bh->b_next);
-}
-
-void bigblock_fat_set_uptodate(struct super_block *sb, struct buffer_head *bh,
-			       int val)
-{
-	mark_buffer_uptodate(bh->b_next, val);
-}
-
-int bigblock_fat_is_uptodate(struct super_block *sb, struct buffer_head *bh)
-{
-	return buffer_uptodate(bh->b_next);
-}
-
-void bigblock_fat_ll_rw_block (struct super_block *sb, int opr, int nbreq,
-			       struct buffer_head *bh[32])
-{
-	struct buffer_head *tmp[32];
-	int i;
-
-	for (i = 0; i < nbreq; i++)
-		tmp[i] = bh[i]->b_next;
-	ll_rw_block(opr, nbreq, tmp);
-}
diff -urN linux-2.4.7/fs/fat/cvf.c fat-2.4.7/fs/fat/cvf.c
--- linux-2.4.7/fs/fat/cvf.c	Tue Oct 17 04:58:51 2000
+++ fat-2.4.7/fs/fat/cvf.c	Wed Jul 25 00:39:23 2001
@@ -23,79 +23,32 @@
 
 struct buffer_head *default_fat_bread(struct super_block *,int);
 struct buffer_head *default_fat_getblk(struct super_block *, int);
-struct buffer_head *bigblock_fat_bread(struct super_block *, int);
 void default_fat_brelse(struct super_block *, struct buffer_head *);
-void bigblock_fat_brelse(struct super_block *, struct buffer_head *);
-void default_fat_mark_buffer_dirty (struct super_block *,
-	struct buffer_head *);
-void bigblock_fat_mark_buffer_dirty (struct super_block *,
-	struct buffer_head *);
+void default_fat_mark_buffer_dirty (struct super_block *, struct buffer_head *);
 void default_fat_set_uptodate (struct super_block *, struct buffer_head *,int);
-void bigblock_fat_set_uptodate (struct super_block *, struct buffer_head *,int);
 int default_fat_is_uptodate(struct super_block *, struct buffer_head *);
-int bigblock_fat_is_uptodate(struct super_block *, struct buffer_head *);
 int default_fat_access(struct super_block *sb,int nr,int new_value);
-void default_fat_ll_rw_block (
-	struct super_block *sb,
-	int opr,
-	int nbreq,
-	struct buffer_head *bh[32]);
-void bigblock_fat_ll_rw_block (
-	struct super_block *sb,
-	int opr,
-	int nbreq,
-	struct buffer_head *bh[32]);
+void default_fat_ll_rw_block (struct super_block *sb, int opr, int nbreq,
+			      struct buffer_head *bh[32]);
 int default_fat_bmap(struct inode *inode,int block);
-ssize_t default_fat_file_write(
-	struct file *filp,
-	const char *buf,
-	size_t count,
-	loff_t *ppos);
+ssize_t default_fat_file_write(struct file *filp, const char *buf,
+			       size_t count, loff_t *ppos);
 
 struct cvf_format default_cvf = {
-	0,	/* version - who cares? */	
-	"plain",
-	0,	/* flags - who cares? */
-	NULL,
-	NULL,
-	NULL,
-	default_fat_bread,
-	default_fat_getblk,
-	default_fat_brelse,
-	default_fat_mark_buffer_dirty,
-	default_fat_set_uptodate,
-	default_fat_is_uptodate,
-	default_fat_ll_rw_block,
-	default_fat_access,
-	NULL,
-	default_fat_bmap,
-	generic_file_read,
-	default_fat_file_write,
-	NULL,
-	NULL
-};
-
-struct cvf_format bigblock_cvf = {
-	0,	/* version - who cares? */	
-	"big_blocks",
-	0,	/* flags - who cares? */
-	NULL,
-	NULL,
-	NULL,
-	bigblock_fat_bread,
-	bigblock_fat_bread,
-	bigblock_fat_brelse,
-	bigblock_fat_mark_buffer_dirty,
-	bigblock_fat_set_uptodate,
-	bigblock_fat_is_uptodate,
-	bigblock_fat_ll_rw_block,
-	default_fat_access,
-	NULL,
-	default_fat_bmap,
-	NULL,
-	default_fat_file_write,
-	NULL,
-	NULL
+	cvf_version: 		0,	/* version - who cares? */	
+	cvf_version_text: 	"plain",
+	flags:			0,	/* flags - who cares? */
+	cvf_bread:		default_fat_bread,
+	cvf_getblk:		default_fat_getblk,
+	cvf_brelse:		default_fat_brelse,
+	cvf_mark_buffer_dirty:	default_fat_mark_buffer_dirty,
+	cvf_set_uptodate:	default_fat_set_uptodate,
+	cvf_is_uptodate:	default_fat_is_uptodate,
+	cvf_ll_rw_block:	default_fat_ll_rw_block,
+	fat_access:		default_fat_access,
+	cvf_bmap:		default_fat_bmap,
+	cvf_file_read:		generic_file_read,
+	cvf_file_write:		default_fat_file_write,
 };
 
 struct cvf_format *cvf_formats[MAX_CVF_FORMATS];
diff -urN linux-2.4.7/fs/fat/inode.c fat-2.4.7/fs/fat/inode.c
--- linux-2.4.7/fs/fat/inode.c	Tue Jun 12 11:15:27 2001
+++ fat-2.4.7/fs/fat/inode.c	Wed Jul 25 01:22:35 2001
@@ -36,7 +36,7 @@
 #include <asm/uaccess.h>
 #include <asm/unaligned.h>
 
-extern struct cvf_format default_cvf, bigblock_cvf;
+extern struct cvf_format default_cvf;
 
 /* #define FAT_PARANOIA 1 */
 #define DEBUG_LEVEL 0
@@ -448,8 +448,6 @@
 	hard_blksize = get_hardsect_size(sb->s_dev);
 	if (!hard_blksize)
 		hard_blksize = 512;
-	if (hard_blksize != 512)
-		printk("MSDOS: Hardware sector size is %d\n", hard_blksize);
 
 	opts.isvfat = sbi->options.isvfat;
 	if (!parse_options((char *) data, &fat, &debug, &opts,
@@ -464,8 +462,8 @@
 	set_blocksize(sb->s_dev, hard_blksize);
 	bh = bread(sb->s_dev, 0, sb->s_blocksize);
 	if (bh == NULL) {
-		brelse (bh);
-		goto out_no_bread;
+		printk("FAT: unable to read boot sector\n");
+		goto out_fail;
 	}
 
 /*
@@ -489,15 +487,23 @@
 		CF_LE_W(get_unaligned((unsigned short *) &b->sector_size));
 	if (!logical_sector_size
 	    || (logical_sector_size & (logical_sector_size - 1))) {
-		printk("fatfs: bogus logical sector size %d\n",
+		printk("FAT: bogus logical sector size %d\n",
 		       logical_sector_size);
 		brelse(bh);
 		goto out_invalid;
 	}
 
 	sbi->cluster_size = b->cluster_size;
-	if (!sbi->cluster_size || (sbi->cluster_size & (sbi->cluster_size - 1))) {
-		printk("fatfs: bogus cluster size %d\n", sbi->cluster_size);
+	if (!sbi->cluster_size
+	    || (sbi->cluster_size & (sbi->cluster_size - 1))) {
+		printk("FAT: bogus cluster size %d\n", sbi->cluster_size);
+		brelse(bh);
+		goto out_invalid;
+	}
+
+	if (logical_sector_size < hard_blksize) {
+		printk("FAT: logical sector size too small for device"
+		       " (logical sector size = %d)\n", logical_sector_size);
 		brelse(bh);
 		goto out_invalid;
 	}
@@ -528,8 +534,8 @@
 		if (bh->b_blocknr != fsinfo_block) {
 			fsinfo_bh = bread(sb->s_dev, fsinfo_block, hard_blksize);
 			if (fsinfo_bh == NULL) {
-				printk("FAT: bread failed, fsinfo block %d\n",
-				       fsinfo_block);
+				printk("FAT: bread failed, FSINFO block"
+				       " (blocknr = %d)\n", fsinfo_block);
 				brelse(bh);
 				goto out_invalid;
 			}
@@ -585,20 +591,14 @@
 
 	sb->s_blocksize = logical_sector_size;
 	sb->s_blocksize_bits = ffs(logical_sector_size) - 1;
-	if (sb->s_blocksize >= hard_blksize) {
-		set_blocksize(sb->s_dev, sb->s_blocksize);
-		sbi->cvf_format = &default_cvf;
-	} else {
-		set_blocksize(sb->s_dev, hard_blksize);
-		sbi->cvf_format = &bigblock_cvf;
-	}
-
-	if (!strcmp(cvf_format,"none"))
+	set_blocksize(sb->s_dev, sb->s_blocksize);
+	sbi->cvf_format = &default_cvf;
+	if (!strcmp(cvf_format, "none"))
 		i = -1;
 	else
 		i = detect_cvf(sb,cvf_format);
 	if (i >= 0)
-		error = cvf_formats[i]->mount_cvf(sb,cvf_options);
+		error = cvf_formats[i]->mount_cvf(sb, cvf_options);
 	if (error || debug) {
 		/* The MSDOS_CAN_BMAP is obsolete, but left just to remember */
 		printk("[MS-DOS FS Rel. 12,FAT %d,check=%c,conv=%c,"
@@ -607,16 +607,14 @@
 		       opts.conversion,opts.fs_uid,opts.fs_gid,opts.fs_umask,
 		       MSDOS_CAN_BMAP(sbi) ? ",bmap" : "");
 		printk("[me=0x%x,cs=%d,#f=%d,fs=%d,fl=%ld,ds=%ld,de=%d,data=%ld,"
-		       "se=%d,ts=%ld,ls=%d,rc=%ld,fc=%u]\n",
-		       b->media,sbi->cluster_size,
-		       sbi->fats,sbi->fat_start,
-		       sbi->fat_length,
-		       sbi->dir_start,sbi->dir_entries,
-		       sbi->data_start,
-		       CF_LE_W(*(unsigned short *) &b->sectors),
-		       (unsigned long)b->total_sect,logical_sector_size,
-		       sbi->root_cluster,sbi->free_clusters);
-		printk ("Transaction block size = %d\n", hard_blksize);
+		       "se=%u,ts=%u,ls=%d,rc=%ld,fc=%u]\n",
+		       b->media, sbi->cluster_size, sbi->fats,
+		       sbi->fat_start, sbi->fat_length, sbi->dir_start,
+		       sbi->dir_entries, sbi->data_start,
+		       CF_LE_W(get_unaligned((unsigned short *)&b->sectors)),
+		       CF_LE_L(b->total_sect), logical_sector_size,
+		       sbi->root_cluster, sbi->free_clusters);
+		printk ("hard sector size = %d\n", hard_blksize);
 	}
 	if (i < 0)
 		if (sbi->clusters + 2 > fat_clusters)
@@ -653,7 +651,7 @@
 	if (! sbi->nls_io)
 		sbi->nls_io = load_nls_default();
 
-	root_inode=new_inode(sb);
+	root_inode = new_inode(sb);
 	if (!root_inode)
 		goto out_unload_nls;
 	root_inode->i_ino = MSDOS_ROOT_INO;
@@ -662,29 +660,27 @@
 	sb->s_root = d_alloc_root(root_inode);
 	if (!sb->s_root)
 		goto out_no_root;
-	if(i>=0) {
+	if(i >= 0) {
 		sbi->cvf_format = cvf_formats[i];
 		++cvf_format_use_count[i];
 	}
 	return sb;
 
 out_no_root:
-	printk("get root inode failed\n");
+	printk("FAT: get root inode failed\n");
 	iput(root_inode);
 	unload_nls(sbi->nls_io);
 out_unload_nls:
 	unload_nls(sbi->nls_disk);
 	goto out_fail;
 out_invalid:
-	if (!silent)
-		printk("VFS: Can't find a valid MSDOS filesystem on dev %s.\n",
+	if (!silent) {
+		printk("VFS: Can't find a valid FAT filesystem on dev %s.\n",
 			kdevname(sb->s_dev));
-	goto out_fail;
-out_no_bread:
-	printk("FAT bread failed\n");
+	}
 out_fail:
 	if (opts.iocharset) {
-		printk("VFS: freeing iocharset=%s\n", opts.iocharset);
+		printk("FAT: freeing iocharset=%s\n", opts.iocharset);
 		kfree(opts.iocharset);
 	}
 	if(sbi->private_data)
#5 lore raw
In reply to Jens Axboe
Quoted 10 lines · Alan Cox
Quoted 5 lines

FAT oopses, right?

It will not be fixed (Logical sector size smaller than device sector size) directly, there needs to be support for this type of thing. For now folks should just use loop on top of DVD-RAM, for instance.

Oopses are bad. It means any random user can trick you into crashing your box just by swapping media around or you crash it in error

I/O error by all means - but oops is a bug

I'm not disagreeing, I'm just saying how I would like to see it get fixed. That's all.

Signature · 1 line
Jens Axboe