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-rw-r--r--drivers/md/raid1-10.c81
1 files changed, 81 insertions, 0 deletions
diff --git a/drivers/md/raid1-10.c b/drivers/md/raid1-10.c
new file mode 100644
index 000000000000..9f2670b45f31
--- /dev/null
+++ b/drivers/md/raid1-10.c
@@ -0,0 +1,81 @@
+/* Maximum size of each resync request */
+#define RESYNC_BLOCK_SIZE (64*1024)
+#define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
+
+/* for managing resync I/O pages */
+struct resync_pages {
+ void *raid_bio;
+ struct page *pages[RESYNC_PAGES];
+};
+
+static inline int resync_alloc_pages(struct resync_pages *rp,
+ gfp_t gfp_flags)
+{
+ int i;
+
+ for (i = 0; i < RESYNC_PAGES; i++) {
+ rp->pages[i] = alloc_page(gfp_flags);
+ if (!rp->pages[i])
+ goto out_free;
+ }
+
+ return 0;
+
+out_free:
+ while (--i >= 0)
+ put_page(rp->pages[i]);
+ return -ENOMEM;
+}
+
+static inline void resync_free_pages(struct resync_pages *rp)
+{
+ int i;
+
+ for (i = 0; i < RESYNC_PAGES; i++)
+ put_page(rp->pages[i]);
+}
+
+static inline void resync_get_all_pages(struct resync_pages *rp)
+{
+ int i;
+
+ for (i = 0; i < RESYNC_PAGES; i++)
+ get_page(rp->pages[i]);
+}
+
+static inline struct page *resync_fetch_page(struct resync_pages *rp,
+ unsigned idx)
+{
+ if (WARN_ON_ONCE(idx >= RESYNC_PAGES))
+ return NULL;
+ return rp->pages[idx];
+}
+
+/*
+ * 'strct resync_pages' stores actual pages used for doing the resync
+ * IO, and it is per-bio, so make .bi_private points to it.
+ */
+static inline struct resync_pages *get_resync_pages(struct bio *bio)
+{
+ return bio->bi_private;
+}
+
+/* generally called after bio_reset() for reseting bvec */
+static void md_bio_reset_resync_pages(struct bio *bio, struct resync_pages *rp,
+ int size)
+{
+ int idx = 0;
+
+ /* initialize bvec table again */
+ do {
+ struct page *page = resync_fetch_page(rp, idx);
+ int len = min_t(int, size, PAGE_SIZE);
+
+ /*
+ * won't fail because the vec table is big
+ * enough to hold all these pages
+ */
+ bio_add_page(bio, page, len, 0);
+ size -= len;
+ } while (idx++ < RESYNC_PAGES && size > 0);
+}