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/dir_f.c b/fs/adfs/dir_f.c
index bafc712..4bbe853 100644
--- a/fs/adfs/dir_f.c
+++ b/fs/adfs/dir_f.c
@@ -52,7 +52,6 @@ static inline int adfs_readname(char *buf, char *ptr, int maxlen)
 			*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, struct adfs_direntry *de)
 	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 pos, struct object_info *obj)
 	if (!de.dirobname[0])
 		return -ENOENT;
 
-	adfs_dir2obj(obj, &de);
+	adfs_dir2obj(dir, obj, &de);
 
 	return 0;
 }