md/r5cache: refactoring journal recovery code

1. rename r5l_read_meta_block() as r5l_recovery_read_meta_block();
2. pull the code that initialize r5l_meta_block from
   r5l_log_write_empty_meta_block() to a separate function
   r5l_recovery_create_empty_meta_block(), so that we can reuse this
   piece of code.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>

diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index b9ad0e8fcf679240d675b5a1a6db26fcba52f9d7..390be840c7640beb6817e3c73a3d119a13c1e507 100644 (file)
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -1356,8 +1356,8 @@ struct r5l_recovery_ctx {
        u64 seq;                        /* recovery position seq */
 };
 
-static int r5l_read_meta_block(struct r5l_log *log,
-                              struct r5l_recovery_ctx *ctx)
+static int r5l_recovery_read_meta_block(struct r5l_log *log,
+                                       struct r5l_recovery_ctx *ctx)
 {
        struct page *page = ctx->meta_page;
        struct r5l_meta_block *mb;
@@ -1530,7 +1530,7 @@ static void r5l_recovery_flush_log(struct r5l_log *log,
                                   struct r5l_recovery_ctx *ctx)
 {
        while (1) {
-               if (r5l_read_meta_block(log, ctx))
+               if (r5l_recovery_read_meta_block(log, ctx))
                        return;
                if (r5l_recovery_flush_one_meta(log, ctx))
                        return;
@@ -1539,17 +1539,16 @@ static void r5l_recovery_flush_log(struct r5l_log *log,
        }
 }
 
-static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
-                                         u64 seq)
+static void
+r5l_recovery_create_empty_meta_block(struct r5l_log *log,
+                                    struct page *page,
+                                    sector_t pos, u64 seq)
 {
-       struct page *page;
        struct r5l_meta_block *mb;
        u32 crc;
 
-       page = alloc_page(GFP_KERNEL | __GFP_ZERO);
-       if (!page)
-               return -ENOMEM;
        mb = page_address(page);
+       clear_page(mb);
        mb->magic = cpu_to_le32(R5LOG_MAGIC);
        mb->version = R5LOG_VERSION;
        mb->meta_size = cpu_to_le32(sizeof(struct r5l_meta_block));
@@ -1557,7 +1556,17 @@ static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
        mb->position = cpu_to_le64(pos);
        crc = crc32c_le(log->uuid_checksum, mb, PAGE_SIZE);
        mb->checksum = cpu_to_le32(crc);
+}
 
+static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
+                                         u64 seq)
+{
+       struct page *page;
+
+       page = alloc_page(GFP_KERNEL);
+       if (!page)
+               return -ENOMEM;
+       r5l_recovery_create_empty_meta_block(log, page, pos, seq);
        if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, REQ_OP_WRITE,
                          WRITE_FUA, false)) {
                __free_page(page);