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@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 20 insertions, 3 deletions

diff --git a/fs/adfs/super.c b/fs/adfs/super.c
index 06d7388b477b..c8bf36a1996a 100644
--- a/fs/adfs/super.c
+++ b/fs/adfs/super.c
@@ -138,17 +138,20 @@ static int adfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
                 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}
 };
 
@@ -189,6 +192,11 @@ static int parse_options(struct super_block *sb, char *options)
                                 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);
@@ -366,6 +374,7 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent)
         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;
@@ -445,11 +454,13 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent)
 
         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,
@@ -463,6 +474,12 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent)
                 asb->s_dir     = &adfs_f_dir_ops;
                 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;
 
         sb->s_d_op = &adfs_dentry_operations;
         root = adfs_iget(sb, &root_obj);