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linux-next/fs/adfs/dir_fplus.c
Stuart Swales da23ef0549 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>
2011-03-22 17:44:17 -07:00

266 lines
6.2 KiB
C

/*
* linux/fs/adfs/dir_fplus.c
*
* Copyright (C) 1997-1999 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/buffer_head.h>
#include <linux/slab.h>
#include "adfs.h"
#include "dir_fplus.h"
static int
adfs_fplus_read(struct super_block *sb, unsigned int id, unsigned int sz, struct adfs_dir *dir)
{
struct adfs_bigdirheader *h;
struct adfs_bigdirtail *t;
unsigned long block;
unsigned int blk, size;
int i, ret = -EIO;
dir->nr_buffers = 0;
/* start off using fixed bh set - only alloc for big dirs */
dir->bh_fplus = &dir->bh[0];
block = __adfs_block_map(sb, id, 0);
if (!block) {
adfs_error(sb, "dir object %X has a hole at offset 0", id);
goto out;
}
dir->bh_fplus[0] = sb_bread(sb, block);
if (!dir->bh_fplus[0])
goto out;
dir->nr_buffers += 1;
h = (struct adfs_bigdirheader *)dir->bh_fplus[0]->b_data;
size = le32_to_cpu(h->bigdirsize);
if (size != sz) {
printk(KERN_WARNING "adfs: adfs_fplus_read:"
" directory header size %X\n"
" does not match directory size %X\n",
size, sz);
}
if (h->bigdirversion[0] != 0 || h->bigdirversion[1] != 0 ||
h->bigdirversion[2] != 0 || size & 2047 ||
h->bigdirstartname != cpu_to_le32(BIGDIRSTARTNAME)) {
printk(KERN_WARNING "adfs: dir object %X has"
" malformed dir header\n", id);
goto out;
}
size >>= sb->s_blocksize_bits;
if (size > sizeof(dir->bh)/sizeof(dir->bh[0])) {
/* this directory is too big for fixed bh set, must allocate */
struct buffer_head **bh_fplus =
kzalloc(size * sizeof(struct buffer_head *),
GFP_KERNEL);
if (!bh_fplus) {
adfs_error(sb, "not enough memory for"
" dir object %X (%d blocks)", id, size);
goto out;
}
dir->bh_fplus = bh_fplus;
/* copy over the pointer to the block that we've already read */
dir->bh_fplus[0] = dir->bh[0];
}
for (blk = 1; blk < size; blk++) {
block = __adfs_block_map(sb, id, blk);
if (!block) {
adfs_error(sb, "dir object %X has a hole at offset %d", id, blk);
goto out;
}
dir->bh_fplus[blk] = sb_bread(sb, block);
if (!dir->bh_fplus[blk]) {
adfs_error(sb, "dir object %X failed read for"
" offset %d, mapped block %X",
id, blk, block);
goto out;
}
dir->nr_buffers += 1;
}
t = (struct adfs_bigdirtail *)
(dir->bh_fplus[size - 1]->b_data + (sb->s_blocksize - 8));
if (t->bigdirendname != cpu_to_le32(BIGDIRENDNAME) ||
t->bigdirendmasseq != h->startmasseq ||
t->reserved[0] != 0 || t->reserved[1] != 0) {
printk(KERN_WARNING "adfs: dir object %X has "
"malformed dir end\n", id);
goto out;
}
dir->parent_id = le32_to_cpu(h->bigdirparent);
dir->sb = sb;
return 0;
out:
if (dir->bh_fplus) {
for (i = 0; i < dir->nr_buffers; i++)
brelse(dir->bh_fplus[i]);
if (&dir->bh[0] != dir->bh_fplus)
kfree(dir->bh_fplus);
dir->bh_fplus = NULL;
}
dir->nr_buffers = 0;
dir->sb = NULL;
return ret;
}
static int
adfs_fplus_setpos(struct adfs_dir *dir, unsigned int fpos)
{
struct adfs_bigdirheader *h =
(struct adfs_bigdirheader *) dir->bh_fplus[0]->b_data;
int ret = -ENOENT;
if (fpos <= le32_to_cpu(h->bigdirentries)) {
dir->pos = fpos;
ret = 0;
}
return ret;
}
static void
dir_memcpy(struct adfs_dir *dir, unsigned int offset, void *to, int len)
{
struct super_block *sb = dir->sb;
unsigned int buffer, partial, remainder;
buffer = offset >> sb->s_blocksize_bits;
offset &= sb->s_blocksize - 1;
partial = sb->s_blocksize - offset;
if (partial >= len)
memcpy(to, dir->bh_fplus[buffer]->b_data + offset, len);
else {
char *c = (char *)to;
remainder = len - partial;
memcpy(c,
dir->bh_fplus[buffer]->b_data + offset,
partial);
memcpy(c + partial,
dir->bh_fplus[buffer + 1]->b_data,
remainder);
}
}
static int
adfs_fplus_getnext(struct adfs_dir *dir, struct object_info *obj)
{
struct adfs_bigdirheader *h =
(struct adfs_bigdirheader *) dir->bh_fplus[0]->b_data;
struct adfs_bigdirentry bde;
unsigned int offset;
int i, ret = -ENOENT;
if (dir->pos >= le32_to_cpu(h->bigdirentries))
goto out;
offset = offsetof(struct adfs_bigdirheader, bigdirname);
offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
offset += dir->pos * sizeof(struct adfs_bigdirentry);
dir_memcpy(dir, offset, &bde, sizeof(struct adfs_bigdirentry));
obj->loadaddr = le32_to_cpu(bde.bigdirload);
obj->execaddr = le32_to_cpu(bde.bigdirexec);
obj->size = le32_to_cpu(bde.bigdirlen);
obj->file_id = le32_to_cpu(bde.bigdirindaddr);
obj->attr = le32_to_cpu(bde.bigdirattr);
obj->name_len = le32_to_cpu(bde.bigdirobnamelen);
offset = offsetof(struct adfs_bigdirheader, bigdirname);
offset += ((le32_to_cpu(h->bigdirnamelen) + 4) & ~3);
offset += le32_to_cpu(h->bigdirentries) * sizeof(struct adfs_bigdirentry);
offset += le32_to_cpu(bde.bigdirobnameptr);
dir_memcpy(dir, offset, obj->name, obj->name_len);
for (i = 0; i < obj->name_len; i++)
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:
return ret;
}
static int
adfs_fplus_sync(struct adfs_dir *dir)
{
int err = 0;
int i;
for (i = dir->nr_buffers - 1; i >= 0; i--) {
struct buffer_head *bh = dir->bh_fplus[i];
sync_dirty_buffer(bh);
if (buffer_req(bh) && !buffer_uptodate(bh))
err = -EIO;
}
return err;
}
static void
adfs_fplus_free(struct adfs_dir *dir)
{
int i;
if (dir->bh_fplus) {
for (i = 0; i < dir->nr_buffers; i++)
brelse(dir->bh_fplus[i]);
if (&dir->bh[0] != dir->bh_fplus)
kfree(dir->bh_fplus);
dir->bh_fplus = NULL;
}
dir->nr_buffers = 0;
dir->sb = NULL;
}
struct adfs_dir_ops adfs_fplus_dir_ops = {
.read = adfs_fplus_read,
.setpos = adfs_fplus_setpos,
.getnext = adfs_fplus_getnext,
.sync = adfs_fplus_sync,
.free = adfs_fplus_free
};