yaffs2: Yaffs endian support

[yaffs2.git] / yaffs_checkptrw.c

diff --git a/yaffs_checkptrw.c b/yaffs_checkptrw.c
index e739fb4a104b6261969a5ef869caeb7b87bdbbe3..59ca34afe3ee749aff52f664bfff11d8369ab86e 100644 (file)
--- a/yaffs_checkptrw.c
+++ b/yaffs_checkptrw.c
@@ -13,6 +13,7 @@
 
 #include "yaffs_checkptrw.h"
 #include "yaffs_getblockinfo.h"
+#include "yaffs_endian.h"
 
 struct yaffs_checkpt_chunk_hdr {
        int version;
@@ -32,6 +33,18 @@ static int apply_block_offset(struct yaffs_dev *dev, int block)
        return block - dev->block_offset;
 }
 
+
+static void yaffs2_do_endian_hdr(struct yaffs_dev *dev,
+                                struct yaffs_checkpt_chunk_hdr *hdr)
+{
+       if (!dev->swap_endian)
+               return;
+       hdr->version = swap_s32(hdr->version);
+       hdr->seq     = swap_s32(hdr->seq);
+       hdr->sum     = swap_u32(hdr->sum);
+       hdr->xor     = swap_u32(hdr->xor);
+}
+
 static void yaffs2_checkpt_init_chunk_hdr(struct yaffs_dev *dev)
 {
        struct yaffs_checkpt_chunk_hdr hdr;
@@ -43,6 +56,7 @@ static void yaffs2_checkpt_init_chunk_hdr(struct yaffs_dev *dev)
 
        dev->checkpt_byte_offs = sizeof(hdr);
 
+       yaffs2_do_endian_hdr(dev, &hdr);
        memcpy(dev->checkpt_buffer, &hdr, sizeof(hdr));
 }
 
@@ -51,6 +65,7 @@ static int yaffs2_checkpt_check_chunk_hdr(struct yaffs_dev *dev)
        struct yaffs_checkpt_chunk_hdr hdr;
 
        memcpy(&hdr, dev->checkpt_buffer, sizeof(hdr));
+       yaffs2_do_endian_hdr(dev, &hdr);
 
        dev->checkpt_byte_offs = sizeof(hdr);
 
@@ -237,8 +252,9 @@ int yaffs2_checkpt_open(struct yaffs_dev *dev, int writing)
        dev->blocks_in_checkpt = 0;
        dev->checkpt_max_blocks =
            (dev->internal_end_block - dev->internal_start_block) / 16 + 2;
-       dev->checkpt_block_list =
-           kmalloc(sizeof(int) * dev->checkpt_max_blocks, GFP_NOFS);
+       if (!dev->checkpt_block_list)
+               dev->checkpt_block_list =
+                     kmalloc(sizeof(int) * dev->checkpt_max_blocks, GFP_NOFS);
 
        if (!dev->checkpt_block_list)
                return 0;
@@ -348,7 +364,6 @@ int yaffs2_checkpt_wr(struct yaffs_dev *dev, const void *data, int n_bytes)
 int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes)
 {
        int i = 0;
-       int ok = 1;
        struct yaffs_ext_tags tags;
        int chunk;
        int offset_chunk;
@@ -360,7 +375,7 @@ int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes)
        if (dev->checkpt_open_write)
                return -1;
 
-       while (i < n_bytes && ok) {
+       while (i < n_bytes) {
 
                if (dev->checkpt_byte_offs < 0 ||
                    dev->checkpt_byte_offs >= dev->data_bytes_per_chunk) {
@@ -370,10 +385,9 @@ int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes)
                                dev->checkpt_cur_chunk = 0;
                        }
 
-                       if (dev->checkpt_cur_block < 0) {
-                               ok = 0;
+                       /* Bail out if we can't find a checpoint block */
+                       if (dev->checkpt_cur_block < 0)
                                break;
-                       }
 
                        chunk = dev->checkpt_cur_block *
                            dev->param.chunks_per_block +
@@ -382,22 +396,21 @@ int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes)
                        offset_chunk = apply_chunk_offset(dev, chunk);
                        dev->n_page_reads++;
 
-                       /* read in the next chunk */
+                       /* Read in the next chunk */
                        dev->tagger.read_chunk_tags_fn(dev,
                                                offset_chunk,
                                                dev->checkpt_buffer,
                                                &tags);
 
+                       /* Bail out if the chunk is corrupted. */
                        if (tags.chunk_id != (dev->checkpt_page_seq + 1) ||
                            tags.ecc_result > YAFFS_ECC_RESULT_FIXED ||
-                           tags.seq_number != YAFFS_SEQUENCE_CHECKPOINT_DATA) {
-                               ok = 0;
+                           tags.seq_number != YAFFS_SEQUENCE_CHECKPOINT_DATA)
                                break;
-                       }
-                       if(!yaffs2_checkpt_check_chunk_hdr(dev)) {
-                               ok = 0;
+
+                       /* Bail out if it is not a checkpoint chunk. */
+                       if(!yaffs2_checkpt_check_chunk_hdr(dev))
                                break;
-                       }
 
                        dev->checkpt_page_seq++;
                        dev->checkpt_cur_chunk++;
@@ -417,7 +430,7 @@ int yaffs2_checkpt_rd(struct yaffs_dev *dev, void *data, int n_bytes)
                dev->checkpt_byte_count++;
        }
 
-       return i;
+       return i; /* Number of bytes read */
 }
 
 int yaffs_checkpt_close(struct yaffs_dev *dev)
@@ -441,8 +454,6 @@ int yaffs_checkpt_close(struct yaffs_dev *dev)
                        if (bi && bi->block_state == YAFFS_BLOCK_STATE_EMPTY)
                                bi->block_state = YAFFS_BLOCK_STATE_CHECKPOINT;
                }
-               kfree(dev->checkpt_block_list);
-               dev->checkpt_block_list = NULL;
        }
 
        dev->n_free_chunks -=
@@ -452,14 +463,10 @@ int yaffs_checkpt_close(struct yaffs_dev *dev)
        yaffs_trace(YAFFS_TRACE_CHECKPOINT, "checkpoint byte count %d",
                dev->checkpt_byte_count);
 
-       if (dev->checkpt_buffer) {
-               /* free the buffer */
-               kfree(dev->checkpt_buffer);
-               dev->checkpt_buffer = NULL;
+       if (dev->checkpt_buffer)
                return 1;
-       } else {
+       else
                return 0;
-       }
 }
 
 int yaffs2_checkpt_invalidate_stream(struct yaffs_dev *dev)