[PATCH] adfs: add hexadecimal filetype suffix option

From: Stuart Swales
Date: Fri Jan 21 2011 - 09:34:22 EST



[PATCH] adfs: add hexadecimal filetype suffix option

ADFS (FileCore) storage complies with the RISC OS filetype specification
(12 bits of file type information is stored in the file load address, rather
than using a file extension). The existing driver largely ignores this
information and does not present it to the end user.

It is desirable that stored filetypes be made visible to the end user to
facilitate a precise copy of data and metadata from a hard disc (or image
thereof) into a RISC OS emulator (such as RPCEmu) or to a network share which
can be accessed by real Acorn systems.

This patch implements a per-mount filetype suffix option (use -o ftsuffix=1)
to present any filetype as a ,xyz hexadecimal suffix on each file. This type
suffix is compatible with that used by RISC OS systems that access network
servers using NFS client software and by RPCemu's host filing system.

Signed-off-by: Stuart Swales <stuart.swales.croftnuisk@xxxxxxxxx>

---

Bugzilla # 26492
(ADFS filesystem filetype metadata lost)

Test files are attached in Bugzilla issue.

NB. Updated patch with style fixes as suggested by Andrew.


diff -X linux-2.6.37-vanilla/Documentation/dontdiff -uprN linux-2.6.37-vanilla/Documentation/filesystems/adfs.txt linux-2.6.37-sks-adfs/Documentation/filesystems/adfs.txt
--- linux-2.6.37-vanilla/Documentation/filesystems/adfs.txt 2011-01-05 00:50:19.000000000 +0000
+++ linux-2.6.37-sks-adfs/Documentation/filesystems/adfs.txt 2011-01-21 14:10:27.000000000 +0000
@@ -9,6 +9,9 @@ Mount options for ADFS
will be nnn. Default 0700.
othmask=nnn The permission mask for ADFS 'other' permissions
will be nnn. Default 0077.
+ ftsuffix=n When ftsuffix=0, no file type suffix will be applied.
+ When ftsuffix=1, a hexadecimal suffix corresponding to
+ the RISC OS file type will be added. Default 0.

Mapping of ADFS permissions to Linux permissions
------------------------------------------------
@@ -55,3 +58,18 @@ Mapping of ADFS permissions to Linux per

You can therefore tailor the permission translation to whatever you
desire the permissions should be under Linux.
+
+RISC OS file type suffix
+------------------------
+
+ RISC OS file types are stored in bits 19..8 of the file load address.
+
+ To enable non-RISC OS systems to be used to store files without losing
+ file type information, a file naming convention was devised (initially
+ for use with NFS) such that a hexadecimal suffix of the form ,xyz
+ denoted the file type: e.g. BasicFile,ffb is a BASIC (0xffb) file. This
+ naming convention is now also used by RISC OS emulators such as RPCEmu.
+
+ Mounting an ADFS disc with option ftsuffix=1 will cause appropriate file
+ type suffixes to be appended to file names read from a directory. If the
+ ftsuffix option is zero or omitted, no file type suffixes will be added.
diff -X linux-2.6.37-vanilla/Documentation/dontdiff -uprN linux-2.6.37-vanilla/fs/adfs/adfs.h linux-2.6.37-sks-adfs/fs/adfs/adfs.h
--- linux-2.6.37-vanilla/fs/adfs/adfs.h 2011-01-05 00:50:19.000000000 +0000
+++ linux-2.6.37-sks-adfs/fs/adfs/adfs.h 2011-01-21 13:50:12.000000000 +0000
@@ -50,6 +50,7 @@ struct adfs_sb_info {
gid_t s_gid; /* owner gid */
umode_t s_owner_mask; /* ADFS owner perm -> unix perm */
umode_t s_other_mask; /* ADFS other perm -> unix perm */
+ int s_ftsuffix; /* ,xyz hex filetype suffix option */

__u32 s_ids_per_zone; /* max. no ids in one zone */
__u32 s_idlen; /* length of ID in map */
@@ -89,7 +90,7 @@ struct adfs_dir {
/*
* This is the overall maximum name length
*/
-#define ADFS_MAX_NAME_LEN 256
+#define ADFS_MAX_NAME_LEN (256 + 4) /* +4 for ,xyz hex filetype suffix */
struct object_info {
__u32 parent_id; /* parent object id */
__u32 file_id; /* object id */
@@ -97,10 +98,26 @@ struct object_info {
__u32 execaddr; /* execution address */
__u32 size; /* size */
__u8 attr; /* RISC OS attributes */
- unsigned char name_len; /* name length */
+ unsigned int name_len; /* name length */
char name[ADFS_MAX_NAME_LEN];/* file name */
+
+ /* RISC OS file type (12-bit: derived from loadaddr) */
+ __u16 filetype;
};

+/* RISC OS 12-bit filetype converts to ,xyz hex filename suffix */
+static inline int append_filetype_suffix(char *buf, __u16 filetype)
+{
+ if (filetype == -1)
+ return 0;
+
+ *buf++ = ',';
+ *buf++ = hex_asc_lo(filetype >> 8);
+ *buf++ = hex_asc_lo(filetype >> 4);
+ *buf++ = hex_asc_lo(filetype >> 0);
+ return 4;
+}
+
struct adfs_dir_ops {
int (*read)(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir);
int (*setpos)(struct adfs_dir *dir, unsigned int fpos);
diff -X linux-2.6.37-vanilla/Documentation/dontdiff -uprN linux-2.6.37-vanilla/fs/adfs/dir_f.c linux-2.6.37-sks-adfs/fs/adfs/dir_f.c
--- linux-2.6.37-vanilla/fs/adfs/dir_f.c 2011-01-05 00:50:19.000000000 +0000
+++ linux-2.6.37-sks-adfs/fs/adfs/dir_f.c 2011-01-21 13:52:57.000000000 +0000
@@ -52,7 +52,6 @@ static inline int adfs_readname(char *bu
*buf++ = *ptr;
ptr++;
}
- *buf = '\0';

return buf - old_buf;
}
@@ -208,7 +207,8 @@ release_buffers:
* convert a disk-based directory entry to a Linux ADFS directory entry
*/
static inline void
-adfs_dir2obj(struct object_info *obj, struct adfs_direntry *de)
+adfs_dir2obj(struct adfs_dir *dir, struct object_info *obj,
+ struct adfs_direntry *de)
{
obj->name_len = adfs_readname(obj->name, de->dirobname, ADFS_F_NAME_LEN);
obj->file_id = adfs_readval(de->dirinddiscadd, 3);
@@ -216,6 +216,23 @@ adfs_dir2obj(struct object_info *obj, st
obj->execaddr = adfs_readval(de->direxec, 4);
obj->size = adfs_readval(de->dirlen, 4);
obj->attr = de->newdiratts;
+ obj->filetype = -1;
+
+ /*
+ * object is a file and is filetyped and timestamped?
+ * RISC OS 12-bit filetype is stored in load_address[19:8]
+ */
+ if ((0 == (obj->attr & ADFS_NDA_DIRECTORY)) &&
+ (0xfff00000 == (0xfff00000 & obj->loadaddr))) {
+ obj->filetype = (__u16) ((0x000fff00 & obj->loadaddr) >> 8);
+
+ /* optionally append the ,xyz hex filetype suffix */
+ if (ADFS_SB(dir->sb)->s_ftsuffix)
+ obj->name_len +=
+ append_filetype_suffix(
+ &obj->name[obj->name_len],
+ obj->filetype);
+ }
}

/*
@@ -260,7 +277,7 @@ __adfs_dir_get(struct adfs_dir *dir, int
if (!de.dirobname[0])
return -ENOENT;

- adfs_dir2obj(obj, &de);
+ adfs_dir2obj(dir, obj, &de);

return 0;
}
diff -X linux-2.6.37-vanilla/Documentation/dontdiff -uprN linux-2.6.37-vanilla/fs/adfs/dir_fplus.c linux-2.6.37-sks-adfs/fs/adfs/dir_fplus.c
--- linux-2.6.37-vanilla/fs/adfs/dir_fplus.c 2011-01-05 00:50:19.000000000 +0000
+++ linux-2.6.37-sks-adfs/fs/adfs/dir_fplus.c 2011-01-21 13:53:43.000000000 +0000
@@ -147,6 +147,24 @@ adfs_fplus_getnext(struct adfs_dir *dir,
if (obj->name[i] == '/')
obj->name[i] = '.';

+ obj->filetype = -1;
+
+ /*
+ * object is a file and is filetyped and timestamped?
+ * RISC OS 12-bit filetype is stored in load_address[19:8]
+ */
+ if ((0 == (obj->attr & ADFS_NDA_DIRECTORY)) &&
+ (0xfff00000 == (0xfff00000 & obj->loadaddr))) {
+ obj->filetype = (__u16) ((0x000fff00 & obj->loadaddr) >> 8);
+
+ /* optionally append the ,xyz hex filetype suffix */
+ if (ADFS_SB(dir->sb)->s_ftsuffix)
+ obj->name_len +=
+ append_filetype_suffix(
+ &obj->name[obj->name_len],
+ obj->filetype);
+ }
+
dir->pos += 1;
ret = 0;
out:
diff -X linux-2.6.37-vanilla/Documentation/dontdiff -uprN linux-2.6.37-vanilla/fs/adfs/inode.c linux-2.6.37-sks-adfs/fs/adfs/inode.c
--- linux-2.6.37-vanilla/fs/adfs/inode.c 2011-01-05 00:50:19.000000000 +0000
+++ linux-2.6.37-sks-adfs/fs/adfs/inode.c 2011-01-21 13:48:38.000000000 +0000
@@ -79,26 +79,13 @@ static const struct address_space_operat
.bmap = _adfs_bmap
};

-static inline unsigned int
-adfs_filetype(struct inode *inode)
-{
- unsigned int type;
-
- if (ADFS_I(inode)->stamped)
- type = (ADFS_I(inode)->loadaddr >> 8) & 0xfff;
- else
- type = (unsigned int) -1;
-
- return type;
-}
-
/*
* Convert ADFS attributes and filetype to Linux permission.
*/
static umode_t
adfs_atts2mode(struct super_block *sb, struct inode *inode)
{
- unsigned int filetype, attr = ADFS_I(inode)->attr;
+ unsigned int attr = ADFS_I(inode)->attr;
umode_t mode, rmask;
struct adfs_sb_info *asb = ADFS_SB(sb);

@@ -107,9 +94,7 @@ adfs_atts2mode(struct super_block *sb, s
return S_IFDIR | S_IXUGO | mode;
}

- filetype = adfs_filetype(inode);
-
- switch (filetype) {
+ switch (ADFS_I(inode)->filetype) {
case 0xfc0: /* LinkFS */
return S_IFLNK|S_IRWXUGO;

@@ -280,7 +265,8 @@ adfs_iget(struct super_block *sb, struct
ADFS_I(inode)->loadaddr = obj->loadaddr;
ADFS_I(inode)->execaddr = obj->execaddr;
ADFS_I(inode)->attr = obj->attr;
- ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000);
+ ADFS_I(inode)->filetype = obj->filetype;
+ ADFS_I(inode)->stamped = ((obj->loadaddr & 0xfff00000) == 0xfff00000);

inode->i_mode = adfs_atts2mode(sb, inode);
adfs_adfs2unix_time(&inode->i_mtime, inode);
diff -X linux-2.6.37-vanilla/Documentation/dontdiff -uprN linux-2.6.37-vanilla/fs/adfs/super.c linux-2.6.37-sks-adfs/fs/adfs/super.c
--- linux-2.6.37-vanilla/fs/adfs/super.c 2011-01-05 00:50:19.000000000 +0000
+++ linux-2.6.37-sks-adfs/fs/adfs/super.c 2011-01-21 14:18:01.000000000 +0000
@@ -143,17 +143,20 @@ static int adfs_show_options(struct seq_
seq_printf(seq, ",ownmask=%o", asb->s_owner_mask);
if (asb->s_other_mask != ADFS_DEFAULT_OTHER_MASK)
seq_printf(seq, ",othmask=%o", asb->s_other_mask);
+ if (asb->s_ftsuffix != 0)
+ seq_printf(seq, ",ftsuffix=%u", asb->s_ftsuffix);

return 0;
}

-enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_err};
+enum {Opt_uid, Opt_gid, Opt_ownmask, Opt_othmask, Opt_ftsuffix, Opt_err};

static const match_table_t tokens = {
{Opt_uid, "uid=%u"},
{Opt_gid, "gid=%u"},
{Opt_ownmask, "ownmask=%o"},
{Opt_othmask, "othmask=%o"},
+ {Opt_ftsuffix, "ftsuffix=%u"},
{Opt_err, NULL}
};

@@ -194,6 +197,11 @@ static int parse_options(struct super_bl
return -EINVAL;
asb->s_other_mask = option;
break;
+ case Opt_ftsuffix:
+ if (match_int(args, &option))
+ return -EINVAL;
+ asb->s_ftsuffix = option;
+ break;
default:
printk("ADFS-fs: unrecognised mount option \"%s\" "
"or missing value\n", p);
@@ -368,6 +376,7 @@ static int adfs_fill_super(struct super_
asb->s_gid = 0;
asb->s_owner_mask = ADFS_DEFAULT_OWNER_MASK;
asb->s_other_mask = ADFS_DEFAULT_OTHER_MASK;
+ asb->s_ftsuffix = 0;

if (parse_options(sb, data))
goto error;
@@ -447,11 +456,13 @@ static int adfs_fill_super(struct super_

root_obj.parent_id = root_obj.file_id = le32_to_cpu(dr->root);
root_obj.name_len = 0;
- root_obj.loadaddr = 0;
- root_obj.execaddr = 0;
+ /* Set root object date as 01 Jan 1987 00:00:00 */
+ root_obj.loadaddr = 0xfff0003f;
+ root_obj.execaddr = 0xec22c000;
root_obj.size = ADFS_NEWDIR_SIZE;
root_obj.attr = ADFS_NDA_DIRECTORY | ADFS_NDA_OWNER_READ |
ADFS_NDA_OWNER_WRITE | ADFS_NDA_PUBLIC_READ;
+ root_obj.filetype = -1;

/*
* If this is a F+ disk with variable length directories,
@@ -466,6 +477,13 @@ static int adfs_fill_super(struct super_
asb->s_namelen = ADFS_F_NAME_LEN;
}

+ /*
+ * ,xyz hex filetype suffix may be added by driver
+ * to files that have valid RISC OS filetype
+ */
+ if (asb->s_ftsuffix)
+ asb->s_namelen += 4;
+
root = adfs_iget(sb, &root_obj);
sb->s_root = d_alloc_root(root);
if (!sb->s_root) {
--
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