fs: Create a common fs_devread for ext4/reiserfs/zfs

The ext4, reiserfs and zfs filesystems all have their own implementation
of the same function, *_devread. Generalize this function into fs_devread
and put the code into fs/fs_internal.c.

Signed-off-by: Marek Behun <marek.behun@nic.cz>
[trini: Move fs/fs_internal.o hunk to the end of fs/Makefile as all
cases need it]
Signed-off-by: Tom Rini <trini@konsulko.com>

1 files changed, 3 insertions, 83 deletions

diff --git a/fs/zfs/dev.c b/fs/zfs/dev.c
index 2f409e66cd..7dda42b48b 100644
--- a/fs/zfs/dev.c
+++ b/fs/zfs/dev.c
@@ -11,6 +11,7 @@
 
 #include <common.h>
 #include <config.h>
+#include <fs_internal.h>
 #include <zfs_common.h>
 
 static struct blk_desc *zfs_blk_desc;
@@ -25,87 +26,6 @@ void zfs_set_blk_dev(struct blk_desc *rbdd, disk_partition_t *info)
 /* err */
 int zfs_devread(int sector, int byte_offset, int byte_len, char *buf)
 {
-	short sec_buffer[SECTOR_SIZE/sizeof(short)];
-	char *sec_buf = (char *)sec_buffer;
-	unsigned block_len;
-
-	/*
-	 *	Check partition boundaries
-	 */
-	if ((sector < 0) ||
-		((sector + ((byte_offset + byte_len - 1) >> SECTOR_BITS)) >=
-		 part_info->size)) {
-		/*		errnum = ERR_OUTSIDE_PART; */
-		printf(" ** zfs_devread() read outside partition sector %d\n", sector);
-		return 1;
-	}
-
-	/*
-	 *	Get the read to the beginning of a partition.
-	 */
-	sector += byte_offset >> SECTOR_BITS;
-	byte_offset &= SECTOR_SIZE - 1;
-
-	debug(" <%d, %d, %d>\n", sector, byte_offset, byte_len);
-
-	if (zfs_blk_desc == NULL) {
-		printf("** Invalid Block Device Descriptor (NULL)\n");
-		return 1;
-	}
-
-	if (byte_offset != 0) {
-		/* read first part which isn't aligned with start of sector */
-		if (zfs_blk_desc->block_read(zfs_blk_desc,
-					     part_info->start + sector, 1,
-					     (void *)sec_buf) != 1) {
-			printf(" ** zfs_devread() read error **\n");
-			return 1;
-		}
-		memcpy(buf, sec_buf + byte_offset,
-			   min(SECTOR_SIZE - byte_offset, byte_len));
-		buf += min(SECTOR_SIZE - byte_offset, byte_len);
-		byte_len -= min(SECTOR_SIZE - byte_offset, byte_len);
-		sector++;
-	}
-
-	if (byte_len == 0)
-		return 0;
-
-	/*	read sector aligned part */
-	block_len = byte_len & ~(SECTOR_SIZE - 1);
-
-	if (block_len == 0) {
-		u8 p[SECTOR_SIZE];
-
-		block_len = SECTOR_SIZE;
-		zfs_blk_desc->block_read(zfs_blk_desc,
-					 part_info->start + sector,
-					 1, (void *)p);
-		memcpy(buf, p, byte_len);
-		return 0;
-	}
-
-	if (zfs_blk_desc->block_read(zfs_blk_desc, part_info->start + sector,
-				     block_len / SECTOR_SIZE,
-				     (void *)buf) != block_len / SECTOR_SIZE) {
-		printf(" ** zfs_devread() read error - block\n");
-		return 1;
-	}
-
-	block_len = byte_len & ~(SECTOR_SIZE - 1);
-	buf += block_len;
-	byte_len -= block_len;
-	sector += block_len / SECTOR_SIZE;
-
-	if (byte_len != 0) {
-		/* read rest of data which are not in whole sector */
-		if (zfs_blk_desc->block_read(zfs_blk_desc,
-					     part_info->start + sector,
-					     1, (void *)sec_buf) != 1) {
-			printf(" ** zfs_devread() read error - last part\n");
-			return 1;
-		}
-		memcpy(buf, sec_buf, byte_len);
-	}
-	return 0;
+	return fs_devread(zfs_blk_desc, part_info, sector, byte_offset,
+			  byte_len, buf);
 }