1 files changed, 457 insertions, 0 deletions
diff --git a/fs/adfs/dir.c b/fs/adfs/dir.c
new file mode 100644
index 000000000..77fbd1960
--- /dev/null
+++ b/fs/adfs/dir.c
@@ -0,0 +1,457 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  linux/fs/adfs/dir.c
+ *
+ *  Copyright (C) 1999-2000 Russell King
+ *
+ *  Common directory handling for ADFS
+ */
+#include <linux/slab.h>
+#include "adfs.h"
+
+/*
+ * For future.  This should probably be per-directory.
+ */
+static DECLARE_RWSEM(adfs_dir_rwsem);
+
+int adfs_dir_copyfrom(void *dst, struct adfs_dir *dir, unsigned int offset,
+		      size_t len)
+{
+	struct super_block *sb = dir->sb;
+	unsigned int index, remain;
+
+	index = offset >> sb->s_blocksize_bits;
+	offset &= sb->s_blocksize - 1;
+	remain = sb->s_blocksize - offset;
+	if (index + (remain < len) >= dir->nr_buffers)
+		return -EINVAL;
+
+	if (remain < len) {
+		memcpy(dst, dir->bhs[index]->b_data + offset, remain);
+		dst += remain;
+		len -= remain;
+		index += 1;
+		offset = 0;
+	}
+
+	memcpy(dst, dir->bhs[index]->b_data + offset, len);
+
+	return 0;
+}
+
+int adfs_dir_copyto(struct adfs_dir *dir, unsigned int offset, const void *src,
+		    size_t len)
+{
+	struct super_block *sb = dir->sb;
+	unsigned int index, remain;
+
+	index = offset >> sb->s_blocksize_bits;
+	offset &= sb->s_blocksize - 1;
+	remain = sb->s_blocksize - offset;
+	if (index + (remain < len) >= dir->nr_buffers)
+		return -EINVAL;
+
+	if (remain < len) {
+		memcpy(dir->bhs[index]->b_data + offset, src, remain);
+		src += remain;
+		len -= remain;
+		index += 1;
+		offset = 0;
+	}
+
+	memcpy(dir->bhs[index]->b_data + offset, src, len);
+
+	return 0;
+}
+
+static void __adfs_dir_cleanup(struct adfs_dir *dir)
+{
+	dir->nr_buffers = 0;
+
+	if (dir->bhs != dir->bh)
+		kfree(dir->bhs);
+	dir->bhs = NULL;
+	dir->sb = NULL;
+}
+
+void adfs_dir_relse(struct adfs_dir *dir)
+{
+	unsigned int i;
+
+	for (i = 0; i < dir->nr_buffers; i++)
+		brelse(dir->bhs[i]);
+
+	__adfs_dir_cleanup(dir);
+}
+
+static void adfs_dir_forget(struct adfs_dir *dir)
+{
+	unsigned int i;
+
+	for (i = 0; i < dir->nr_buffers; i++)
+		bforget(dir->bhs[i]);
+
+	__adfs_dir_cleanup(dir);
+}
+
+int adfs_dir_read_buffers(struct super_block *sb, u32 indaddr,
+			  unsigned int size, struct adfs_dir *dir)
+{
+	struct buffer_head **bhs;
+	unsigned int i, num;
+	int block;
+
+	num = ALIGN(size, sb->s_blocksize) >> sb->s_blocksize_bits;
+	if (num > ARRAY_SIZE(dir->bh)) {
+		/* We only allow one extension */
+		if (dir->bhs != dir->bh)
+			return -EINVAL;
+
+		bhs = kcalloc(num, sizeof(*bhs), GFP_KERNEL);
+		if (!bhs)
+			return -ENOMEM;
+
+		if (dir->nr_buffers)
+			memcpy(bhs, dir->bhs, dir->nr_buffers * sizeof(*bhs));
+
+		dir->bhs = bhs;
+	}
+
+	for (i = dir->nr_buffers; i < num; i++) {
+		block = __adfs_block_map(sb, indaddr, i);
+		if (!block) {
+			adfs_error(sb, "dir %06x has a hole at offset %u",
+				   indaddr, i);
+			goto error;
+		}
+
+		dir->bhs[i] = sb_bread(sb, block);
+		if (!dir->bhs[i]) {
+			adfs_error(sb,
+				   "dir %06x failed read at offset %u, mapped block 0x%08x",
+				   indaddr, i, block);
+			goto error;
+		}
+
+		dir->nr_buffers++;
+	}
+	return 0;
+
+error:
+	adfs_dir_relse(dir);
+
+	return -EIO;
+}
+
+static int adfs_dir_read(struct super_block *sb, u32 indaddr,
+			 unsigned int size, struct adfs_dir *dir)
+{
+	dir->sb = sb;
+	dir->bhs = dir->bh;
+	dir->nr_buffers = 0;
+
+	return ADFS_SB(sb)->s_dir->read(sb, indaddr, size, dir);
+}
+
+static int adfs_dir_read_inode(struct super_block *sb, struct inode *inode,
+			       struct adfs_dir *dir)
+{
+	int ret;
+
+	ret = adfs_dir_read(sb, ADFS_I(inode)->indaddr, inode->i_size, dir);
+	if (ret)
+		return ret;
+
+	if (ADFS_I(inode)->parent_id != dir->parent_id) {
+		adfs_error(sb,
+			   "parent directory id changed under me! (%06x but got %06x)\n",
+			   ADFS_I(inode)->parent_id, dir->parent_id);
+		adfs_dir_relse(dir);
+		ret = -EIO;
+	}
+
+	return ret;
+}
+
+static void adfs_dir_mark_dirty(struct adfs_dir *dir)
+{
+	unsigned int i;
+
+	/* Mark the buffers dirty */
+	for (i = 0; i < dir->nr_buffers; i++)
+		mark_buffer_dirty(dir->bhs[i]);
+}
+
+static int adfs_dir_sync(struct adfs_dir *dir)
+{
+	int err = 0;
+	int i;
+
+	for (i = dir->nr_buffers - 1; i >= 0; i--) {
+		struct buffer_head *bh = dir->bhs[i];
+		sync_dirty_buffer(bh);
+		if (buffer_req(bh) && !buffer_uptodate(bh))
+			err = -EIO;
+	}
+
+	return err;
+}
+
+void adfs_object_fixup(struct adfs_dir *dir, struct object_info *obj)
+{
+	unsigned int dots, i;
+
+	/*
+	 * RISC OS allows the use of '/' in directory entry names, so we need
+	 * to fix these up.  '/' is typically used for FAT compatibility to
+	 * represent '.', so do the same conversion here.  In any case, '.'
+	 * will never be in a RISC OS name since it is used as the pathname
+	 * separator.  Handle the case where we may generate a '.' or '..'
+	 * name, replacing the first character with '^' (the RISC OS "parent
+	 * directory" character.)
+	 */
+	for (i = dots = 0; i < obj->name_len; i++)
+		if (obj->name[i] == '/') {
+			obj->name[i] = '.';
+			dots++;
+		}
+
+	if (obj->name_len <= 2 && dots == obj->name_len)
+		obj->name[0] = '^';
+
+	/*
+	 * If the object is a file, and the user requested the ,xyz hex
+	 * filetype suffix to the name, check the filetype and append.
+	 */
+	if (!(obj->attr & ADFS_NDA_DIRECTORY) && ADFS_SB(dir->sb)->s_ftsuffix) {
+		u16 filetype = adfs_filetype(obj->loadaddr);
+
+		if (filetype != ADFS_FILETYPE_NONE) {
+			obj->name[obj->name_len++] = ',';
+			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 8);
+			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 4);
+			obj->name[obj->name_len++] = hex_asc_lo(filetype >> 0);
+		}
+	}
+}
+
+static int adfs_iterate(struct file *file, struct dir_context *ctx)
+{
+	struct inode *inode = file_inode(file);
+	struct super_block *sb = inode->i_sb;
+	const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
+	struct adfs_dir dir;
+	int ret;
+
+	down_read(&adfs_dir_rwsem);
+	ret = adfs_dir_read_inode(sb, inode, &dir);
+	if (ret)
+		goto unlock;
+
+	if (ctx->pos == 0) {
+		if (!dir_emit_dot(file, ctx))
+			goto unlock_relse;
+		ctx->pos = 1;
+	}
+	if (ctx->pos == 1) {
+		if (!dir_emit(ctx, "..", 2, dir.parent_id, DT_DIR))
+			goto unlock_relse;
+		ctx->pos = 2;
+	}
+
+	ret = ops->iterate(&dir, ctx);
+
+unlock_relse:
+	up_read(&adfs_dir_rwsem);
+	adfs_dir_relse(&dir);
+	return ret;
+
+unlock:
+	up_read(&adfs_dir_rwsem);
+	return ret;
+}
+
+int
+adfs_dir_update(struct super_block *sb, struct object_info *obj, int wait)
+{
+	const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
+	struct adfs_dir dir;
+	int ret;
+
+	if (!IS_ENABLED(CONFIG_ADFS_FS_RW))
+		return -EINVAL;
+
+	if (!ops->update)
+		return -EINVAL;
+
+	down_write(&adfs_dir_rwsem);
+	ret = adfs_dir_read(sb, obj->parent_id, 0, &dir);
+	if (ret)
+		goto unlock;
+
+	ret = ops->update(&dir, obj);
+	if (ret)
+		goto forget;
+
+	ret = ops->commit(&dir);
+	if (ret)
+		goto forget;
+	up_write(&adfs_dir_rwsem);
+
+	adfs_dir_mark_dirty(&dir);
+
+	if (wait)
+		ret = adfs_dir_sync(&dir);
+
+	adfs_dir_relse(&dir);
+	return ret;
+
+	/*
+	 * If the updated failed because the entry wasn't found, we can
+	 * just release the buffers. If it was any other error, forget
+	 * the dirtied buffers so they aren't written back to the media.
+	 */
+forget:
+	if (ret == -ENOENT)
+		adfs_dir_relse(&dir);
+	else
+		adfs_dir_forget(&dir);
+unlock:
+	up_write(&adfs_dir_rwsem);
+
+	return ret;
+}
+
+static unsigned char adfs_tolower(unsigned char c)
+{
+	if (c >= 'A' && c <= 'Z')
+		c += 'a' - 'A';
+	return c;
+}
+
+static int __adfs_compare(const unsigned char *qstr, u32 qlen,
+			  const char *str, u32 len)
+{
+	u32 i;
+
+	if (qlen != len)
+		return 1;
+
+	for (i = 0; i < qlen; i++)
+		if (adfs_tolower(qstr[i]) != adfs_tolower(str[i]))
+			return 1;
+
+	return 0;
+}
+
+static int adfs_dir_lookup_byname(struct inode *inode, const struct qstr *qstr,
+				  struct object_info *obj)
+{
+	struct super_block *sb = inode->i_sb;
+	const struct adfs_dir_ops *ops = ADFS_SB(sb)->s_dir;
+	const unsigned char *name;
+	struct adfs_dir dir;
+	u32 name_len;
+	int ret;
+
+	down_read(&adfs_dir_rwsem);
+	ret = adfs_dir_read_inode(sb, inode, &dir);
+	if (ret)
+		goto unlock;
+
+	ret = ops->setpos(&dir, 0);
+	if (ret)
+		goto unlock_relse;
+
+	ret = -ENOENT;
+	name = qstr->name;
+	name_len = qstr->len;
+	while (ops->getnext(&dir, obj) == 0) {
+		if (!__adfs_compare(name, name_len, obj->name, obj->name_len)) {
+			ret = 0;
+			break;
+		}
+	}
+	obj->parent_id = ADFS_I(inode)->indaddr;
+
+unlock_relse:
+	up_read(&adfs_dir_rwsem);
+	adfs_dir_relse(&dir);
+	return ret;
+
+unlock:
+	up_read(&adfs_dir_rwsem);
+	return ret;
+}
+
+const struct file_operations adfs_dir_operations = {
+	.read		= generic_read_dir,
+	.llseek		= generic_file_llseek,
+	.iterate_shared	= adfs_iterate,
+	.fsync		= generic_file_fsync,
+};
+
+static int
+adfs_hash(const struct dentry *parent, struct qstr *qstr)
+{
+	const unsigned char *name;
+	unsigned long hash;
+	u32 len;
+
+	if (qstr->len > ADFS_SB(parent->d_sb)->s_namelen)
+		return -ENAMETOOLONG;
+
+	len = qstr->len;
+	name = qstr->name;
+	hash = init_name_hash(parent);
+	while (len--)
+		hash = partial_name_hash(adfs_tolower(*name++), hash);
+	qstr->hash = end_name_hash(hash);
+
+	return 0;
+}
+
+/*
+ * Compare two names, taking note of the name length
+ * requirements of the underlying filesystem.
+ */
+static int adfs_compare(const struct dentry *dentry, unsigned int len,
+			const char *str, const struct qstr *qstr)
+{
+	return __adfs_compare(qstr->name, qstr->len, str, len);
+}
+
+const struct dentry_operations adfs_dentry_operations = {
+	.d_hash		= adfs_hash,
+	.d_compare	= adfs_compare,
+};
+
+static struct dentry *
+adfs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
+{
+	struct inode *inode = NULL;
+	struct object_info obj;
+	int error;
+
+	error = adfs_dir_lookup_byname(dir, &dentry->d_name, &obj);
+	if (error == 0) {
+		/*
+		 * This only returns NULL if get_empty_inode
+		 * fails.
+		 */
+		inode = adfs_iget(dir->i_sb, &obj);
+		if (!inode)
+			inode = ERR_PTR(-EACCES);
+	} else if (error != -ENOENT) {
+		inode = ERR_PTR(error);
+	}
+	return d_splice_alias(inode, dentry);
+}
+
+/*
+ * directories can handle most operations...
+ */
+const struct inode_operations adfs_dir_inode_operations = {
+	.lookup		= adfs_lookup,
+	.setattr	= adfs_notify_change,
+};