drivers/md/raid1-10.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Maximum size of each resync request */
   3 #define RESYNC_BLOCK_SIZE (64*1024)
   4 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
   5
   6 /* for managing resync I/O pages */
   7 struct resync_pages {
   8         void            *raid_bio;
   9         struct page     *pages[RESYNC_PAGES];
  10 };
  11
  12 static inline int resync_alloc_pages(struct resync_pages *rp,
  13                                      gfp_t gfp_flags)
  14 {
  15         int i;
  16
  17         for (i = 0; i < RESYNC_PAGES; i++) {
  18                 rp->pages[i] = alloc_page(gfp_flags);
  19                 if (!rp->pages[i])
  20                         goto out_free;
  21         }
  22
  23         return 0;
  24
  25 out_free:
  26         while (--i >= 0)
  27                 put_page(rp->pages[i]);
  28         return -ENOMEM;
  29 }
  30
  31 static inline void resync_free_pages(struct resync_pages *rp)
  32 {
  33         int i;
  34
  35         for (i = 0; i < RESYNC_PAGES; i++)
  36                 put_page(rp->pages[i]);
  37 }
  38
  39 static inline void resync_get_all_pages(struct resync_pages *rp)
  40 {
  41         int i;
  42
  43         for (i = 0; i < RESYNC_PAGES; i++)
  44                 get_page(rp->pages[i]);
  45 }
  46
  47 static inline struct page *resync_fetch_page(struct resync_pages *rp,
  48                                              unsigned idx)
  49 {
  50         if (WARN_ON_ONCE(idx >= RESYNC_PAGES))
  51                 return NULL;
  52         return rp->pages[idx];
  53 }
  54
  55 /*
  56  * 'strct resync_pages' stores actual pages used for doing the resync
  57  *  IO, and it is per-bio, so make .bi_private points to it.
  58  */
  59 static inline struct resync_pages *get_resync_pages(struct bio *bio)
  60 {
  61         return bio->bi_private;
  62 }
  63
  64 /* generally called after bio_reset() for reseting bvec */
  65 static void md_bio_reset_resync_pages(struct bio *bio, struct resync_pages *rp,
  66                                int size)
  67 {
  68         int idx = 0;
  69
  70         /* initialize bvec table again */
  71         do {
  72                 struct page *page = resync_fetch_page(rp, idx);
  73                 int len = min_t(int, size, PAGE_SIZE);
  74
  75                 /*
  76                  * won't fail because the vec table is big
  77                  * enough to hold all these pages
  78                  */
  79                 bio_add_page(bio, page, len, 0);
  80                 size -= len;
  81         } while (idx++ < RESYNC_PAGES && size > 0);
  82 }