patch-2.4.20 linux-2.4.20/fs/befs/io.c

• Lines: 99
• Date: Thu Nov 28 15:53:15 2002
• Orig file: linux-2.4.19/fs/befs/io.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/fs/befs/io.c linux-2.4.20/fs/befs/io.c
@@ -0,0 +1,98 @@
+/*
+ * linux/fs/befs/io.c
+ *
+ * Copyright (C) 2001 Will Dyson <will_dyson@pobox.com
+ *
+ * Based on portions of file.c and inode.c 
+ * by Makoto Kato (m_kato@ga2.so-net.ne.jp)
+ *
+ * Many thanks to Dominic Giampaolo, author of Practical File System
+ * Design with the Be File System, for such a helpful book.
+ *
+ */
+
+#include <linux/fs.h>
+
+#include "befs_fs.h"
+
+/*
+ * Converts befs notion of disk addr to a disk offset and uses
+ * linux kernel function bread() to get the buffer containing
+ * the offset. -Will Dyson
+ *
+ */
+
+struct buffer_head *
+befs_bread_iaddr(struct super_block *sb, befs_inode_addr iaddr)
+{
+	struct buffer_head *bh = NULL;
+	befs_blocknr_t block = 0;
+	vfs_blocknr_t vfs_block = 0;
+	befs_sb_info *befs_sb = BEFS_SB(sb);
+
+	befs_debug(sb, "---> Enter befs_read_iaddr() "
+		   "[%u, %hu, %hu]",
+		   iaddr.allocation_group, iaddr.start, iaddr.len);
+
+	if (iaddr.allocation_group > befs_sb->num_ags) {
+		befs_error(sb, "BEFS: Invalid allocation group %u, max is %u",
+			   iaddr.allocation_group, befs_sb->num_ags);
+		goto error;
+	}
+
+	block = iaddr2blockno(sb, &iaddr);
+	vfs_block = (vfs_blocknr_t) block;
+
+	if (vfs_block != block) {
+		befs_error(sb, "Error converting to host blocknr_t. %Lu "
+			   "is larger than the host can use", block);
+		goto error;
+	}
+
+	befs_debug(sb, "befs_read_iaddr: offset = %lu", block);
+
+	bh = bread(sb->s_dev, vfs_block, befs_sb->block_size);
+
+	if (bh == NULL) {
+		befs_error(sb, "Failed to read block %lu", block);
+		goto error;
+	}
+
+	befs_debug(sb, "<--- befs_read_iaddr()");
+	return bh;
+
+      error:
+	befs_debug(sb, "<--- befs_read_iaddr() ERROR");
+	return NULL;
+}
+
+struct buffer_head *
+befs_bread(struct super_block *sb, befs_blocknr_t block)
+{
+	struct buffer_head *bh = NULL;
+	befs_sb_info *befs_sb = BEFS_SB(sb);
+	vfs_blocknr_t vfs_block = (vfs_blocknr_t) block;
+
+	befs_debug(sb, "---> Enter befs_read() %Lu", block);
+
+	if (vfs_block != block) {
+		befs_error(sb, "Error converting to host blocknr_t. %Lu "
+			   "is larger than the host can use", block);
+		goto error;
+	}
+
+	bh = bread(sb->s_dev, vfs_block, befs_sb->block_size);
+
+	if (bh == NULL) {
+		befs_error(sb, "Failed to read block %lu", vfs_block);
+		goto error;
+	}
+
+	befs_debug(sb, "<--- befs_read()");
+
+	return bh;
+
+      error:
+	befs_debug(sb, "<--- befs_read() ERROR");
+	return NULL;
+}