Line data    Source code

       1             : // SPDX-License-Identifier: GPL-2.0
       2             : /*
       3             :  * Copyright (c) 2019 Christoph Hellwig.
       4             :  */
       5             : #include "xfs.h"
       6             : 
       7             : static inline unsigned int bio_max_vecs(unsigned int count)
       8             : {
       9    17737418 :         return bio_max_segs(howmany(count, PAGE_SIZE));
      10             : }
      11             : 
      12             : int
      13    17737418 : xfs_rw_bdev(
      14             :         struct block_device     *bdev,
      15             :         sector_t                sector,
      16             :         unsigned int            count,
      17             :         char                    *data,
      18             :         enum req_op             op)
      19             : 
      20             : {
      21    17737418 :         unsigned int            is_vmalloc = is_vmalloc_addr(data);
      22    17737418 :         unsigned int            left = count;
      23    17737418 :         int                     error;
      24    17737418 :         struct bio              *bio;
      25             : 
      26    17737418 :         if (is_vmalloc && op == REQ_OP_WRITE)
      27             :                 flush_kernel_vmap_range(data, count);
      28             : 
      29    17737418 :         bio = bio_alloc(bdev, bio_max_vecs(left), op | REQ_META | REQ_SYNC,
      30             :                         GFP_KERNEL);
      31    17737418 :         bio->bi_iter.bi_sector = sector;
      32             : 
      33   100666155 :         do {
      34   100666155 :                 struct page     *page = kmem_to_page(data);
      35   100666155 :                 unsigned int    off = offset_in_page(data);
      36   100666155 :                 unsigned int    len = min_t(unsigned, left, PAGE_SIZE - off);
      37             : 
      38   100666155 :                 while (bio_add_page(bio, page, len, off) != len) {
      39           0 :                         struct bio      *prev = bio;
      40             : 
      41           0 :                         bio = bio_alloc(prev->bi_bdev, bio_max_vecs(left),
      42             :                                         prev->bi_opf, GFP_KERNEL);
      43           0 :                         bio->bi_iter.bi_sector = bio_end_sector(prev);
      44           0 :                         bio_chain(prev, bio);
      45             : 
      46           0 :                         submit_bio(prev);
      47             :                 }
      48             : 
      49   100666155 :                 data += len;
      50   100666155 :                 left -= len;
      51   100666155 :         } while (left > 0);
      52             : 
      53    17737418 :         error = submit_bio_wait(bio);
      54    17737418 :         bio_put(bio);
      55             : 
      56    17737418 :         if (is_vmalloc && op == REQ_OP_READ)
      57             :                 invalidate_kernel_vmap_range(data, count);
      58    17737418 :         return error;
      59             : }