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>
diff --git a/fs/fs_internal.c b/fs/fs_internal.c
new file mode 100644
index 0000000..58b4410
--- /dev/null
+++ b/fs/fs_internal.c
@@ -0,0 +1,92 @@
+/*
+ * 2017 by Marek Behun <marek.behun@nic.cz>
+ *
+ * Derived from code in ext4/dev.c, which was based on reiserfs/dev.c
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <compiler.h>
+#include <part.h>
+#include <memalign.h>
+
+int fs_devread(struct blk_desc *blk, disk_partition_t *partition,
+ lbaint_t sector, int byte_offset, int byte_len, char *buf)
+{
+ unsigned block_len;
+ int log2blksz = blk->log2blksz;
+ ALLOC_CACHE_ALIGN_BUFFER(char, sec_buf, (blk ? blk->blksz : 0));
+ if (blk == NULL) {
+ printf("** Invalid Block Device Descriptor (NULL)\n");
+ return 0;
+ }
+
+ /* Check partition boundaries */
+ if ((sector + ((byte_offset + byte_len - 1) >> log2blksz))
+ >= partition->size) {
+ printf("%s read outside partition " LBAFU "\n", __func__,
+ sector);
+ return 0;
+ }
+
+ /* Get the read to the beginning of a partition */
+ sector += byte_offset >> log2blksz;
+ byte_offset &= blk->blksz - 1;
+
+ debug(" <" LBAFU ", %d, %d>\n", sector, byte_offset, byte_len);
+
+ if (byte_offset != 0) {
+ int readlen;
+ /* read first part which isn't aligned with start of sector */
+ if (blk_dread(blk, partition->start + sector, 1,
+ (void *)sec_buf) != 1) {
+ printf(" ** %s read error **\n", __func__);
+ return 0;
+ }
+ readlen = min((int)blk->blksz - byte_offset,
+ byte_len);
+ memcpy(buf, sec_buf + byte_offset, readlen);
+ buf += readlen;
+ byte_len -= readlen;
+ sector++;
+ }
+
+ if (byte_len == 0)
+ return 1;
+
+ /* read sector aligned part */
+ block_len = byte_len & ~(blk->blksz - 1);
+
+ if (block_len == 0) {
+ ALLOC_CACHE_ALIGN_BUFFER(u8, p, blk->blksz);
+
+ block_len = blk->blksz;
+ blk_dread(blk, partition->start + sector, 1,
+ (void *)p);
+ memcpy(buf, p, byte_len);
+ return 1;
+ }
+
+ if (blk_dread(blk, partition->start + sector,
+ block_len >> log2blksz, (void *)buf) !=
+ block_len >> log2blksz) {
+ printf(" ** %s read error - block\n", __func__);
+ return 0;
+ }
+ block_len = byte_len & ~(blk->blksz - 1);
+ buf += block_len;
+ byte_len -= block_len;
+ sector += block_len / blk->blksz;
+
+ if (byte_len != 0) {
+ /* read rest of data which are not in whole sector */
+ if (blk_dread(blk, partition->start + sector, 1,
+ (void *)sec_buf) != 1) {
+ printf("* %s read error - last part\n", __func__);
+ return 0;
+ }
+ memcpy(buf, sec_buf, byte_len);
+ }
+ return 1;
+}