AXFS: axfs_bdev.c

fs/axfs/axfs_bdev.c new file +11 -0

+/******************************************************************************
+ *
+ * axfs_copy_block_data
+ *
+ * Description: Helper function to read data from block device
+ *
+ * Parameters:
+ *    (IN) sb - pointer to super block structure.
+ *
+ *    (IN) dst_addr - pointer to buffer into which data is to be read.
+ *

fs/axfs/axfs_bdev.c new file +11 -0

+{
+	struct axfs_super *sbi = AXFS_SB(sb);
+	u64 boffset = AXFS_FSOFFSET_2_DEVOFFSET(sbi, fsoffset);
+	u64 blocks;
+	u64 blksize = sb->s_blocksize;
+	unsigned long dst;
+	unsigned long src;
+	sector_t block;
+	size_t bytes;
+	struct buffer_head *bh;
+	u64 copied = 0;

mismatch between documentation and implementation WRT the function name ;)

Quoted 15 lines

fs/axfs/axfs_bdev.c new file +15 -0

+{
+      struct axfs_super *sbi = AXFS_SB(sb);
+      u64 boffset = AXFS_FSOFFSET_2_DEVOFFSET(sbi, fsoffset);
+      u64 blocks;
+      u64 blksize = sb->s_blocksize;
+      unsigned long dst;
+      unsigned long src;
+      sector_t block;
+      size_t bytes;
+      struct buffer_head *bh;
+      u64 copied = 0;
+
+      if (len == 0)
+              return 0;
+

fs/axfs/axfs_bdev.c line 87

Quoted 6 lines

fs/axfs/axfs_bdev.c new file +6 -0

+      blocks = len / blksize;
+      if ((len % blksize) > 0)
+              blocks += 1;
+
+      while (copied < len) {
+              /* Explicit casting for ARM linker errors. */

did it try to emit some external div()? Is this still needed?

All the block device code goes here.

Signed-off-by Jared Hulbert <[email protected]>

---

fs/axfs/axfs_bdev.c new file +74 -0

new file mode 100644
index 0000000..4c6f83c
@@ -0,0 +1,158 @@
+/*
+ * Advanced XIP File System for Linux - AXFS
+ *   Readonly, compressed, and XIP filesystem for Linux systems big and small
+ *
+ * Copyright(c) 2008 Numonyx
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * Authors:
+ *  Jared Hulbert <[email protected]>
+ *
+ * Project url: http://axfs.sourceforge.net
+ *
+ * axfs_bdev.c -
+ *   Allows axfs to use block devices or has dummy functions if block
+ *   device support is compiled out of the kernel.
+ *
+ */
+
+#include <linux/axfs.h>
+#include <linux/mount.h>
+#ifdef CONFIG_BLOCK
+#include <linux/buffer_head.h>
+#include <linux/namei.h>
+
+int axfs_fill_super(struct super_block *sb, void *data, int silent);
+
+int axfs_get_sb_bdev(struct file_system_type *fs_type, int flags,
+                    const char *dev_name, struct axfs_super *sbi,
+                    struct vfsmount *mnt, int *err)
+{
+       *err = get_sb_bdev(fs_type, flags, dev_name, sbi, axfs_fill_super, mnt);
+
+       if (*err)
+               return FALSE;
+       return TRUE;
+}
+
+void axfs_kill_block_super(struct super_block *sb)
+{
+       kill_block_super(sb);
+}
+
+/******************************************************************************
+ *
+ * axfs_copy_block_data
+ *
+ * Description: Helper function to read data from block device
+ *
+ * Parameters:
+ *    (IN) sb - pointer to super block structure.
+ *
+ *    (IN) dst_addr - pointer to buffer into which data is to be read.
+ *
+ *    (IN) boffset - offset within block device
+ *
+ *    (IN) len - length of data to be read
+ *
+ * Returns:
+ *     0 or error number
+ *
+ *****************************************************************************/
+int axfs_copy_block(struct super_block *sb, void *dst_addr, u64 fsoffset,
+                   u64 len)
+{
+       struct axfs_super *sbi = AXFS_SB(sb);
+       u64 boffset = AXFS_FSOFFSET_2_DEVOFFSET(sbi, fsoffset);
+       u64 blocks;
+       u64 blksize = sb->s_blocksize;
+       unsigned long dst;
+       unsigned long src;
+       sector_t block;

fs/axfs/axfs_bdev.c new file +73 -1

+       while (copied < len) {
+               /* Explicit casting for ARM linker errors. */
+               block = (sector_t) boffset + (sector_t) copied;
+               block /= (sector_t) blksize;
+               bh = sb_bread(sb, block);
+               src = (unsigned long)bh->b_data;
+               dst = (unsigned long)dst_addr;
+               if (copied == 0) {
+                       /* Explicit casting for ARM linker errors. */
+                       bytes = (size_t) blksize;
+                       bytes -= (size_t) boffset % (size_t) blksize;
+                       if (bytes > len)
+                               bytes = len;
+                       /* Explicit casting for ARM linker errors. */
+                       src += (unsigned long)boffset % (unsigned long)blksize;
+               } else {
+                       dst += copied;
+                       if ((len - copied) < blksize) {
+                               bytes = len - copied;
+                       } else {
+                               bytes = blksize;
+                       }
+               }
+               memcpy((void *)dst, (void *)src, bytes);
+               copied += bytes;
+               brelse(bh);
+       }
+       return 0;
+}
+
+int axfs_is_dev_bdev(char *path)
+{
+       struct nameidata nd;
+       int ret = FALSE;
+
+       if (!path)
+               return FALSE;
+
+       if (path_lookup(path, LOOKUP_FOLLOW, &nd))
+               return FALSE;
+
+       if (S_ISBLK(nd.path.dentry->d_inode->i_mode))
+               ret = TRUE;
+
+       path_put(&nd.path);
+       return ret;
+}
+
+#else
+
+int axfs_get_sb_bdev(struct file_system_type *fs_type, int flags,
+                    const char *dev_name, struct axfs_super *sbi,
+                    struct vfsmount *mnt, int *err)
+{
+       return FALSE;
+}
+
+void axfs_kill_block_super(struct super_block *sb)
+{
+}
+
+int axfs_copy_block(struct super_block *sb, void *dst_addr, u64 fsoffset,
+                   u64 len)
+{
+       return -EINVAL;
+}
+
+int axfs_is_dev_bdev(char *path)
+{
+       return FALSE;
+}
+
+#endif /* CONFIG_BLOCK */
 
 
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