ldiskfs/kernel_patches/patches/rhel6.3/ext4-map_inode_page-2.6.18.patch

   1 diff -ur a/fs/ext4/ext4.h b/fs/ext4/ext4.h
   2 --- a/fs/ext4/ext4.h    2013-03-14 12:04:44.105541822 -0400
   3 +++ b/fs/ext4/ext4.h    2013-03-14 12:09:14.264489405 -0400
   4 @@ -1661,6 +1661,8 @@
   5  extern int ext4_block_truncate_page(handle_t *handle,
   6                 struct address_space *mapping, loff_t from);
   7  extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
   8 +extern int ext4_map_inode_page(struct inode *inode, struct page *page,
   9 +                               unsigned long *blocks, int create);
  10  extern qsize_t *ext4_get_reserved_space(struct inode *inode);
  11  extern int flush_aio_dio_completed_IO(struct inode *inode);
  12  extern void ext4_da_update_reserve_space(struct inode *inode,
  13 diff -ur a/fs/ext4/inode.c b/fs/ext4/inode.c
  14 --- a/fs/ext4/inode.c   2013-03-14 12:04:44.103541330 -0400
  15 +++ b/fs/ext4/inode.c   2013-03-14 12:11:16.526353498 -0400
  16 @@ -6131,3 +6131,62 @@
  17  out:
  18          return ret;
  19  }
  20 +
  21 +int ext4_map_inode_page(struct inode *inode, struct page *page,
  22 +                       unsigned long *blocks, int create)
  23 +{
  24 +       unsigned int blocksize, blocks_per_page;
  25 +       unsigned long iblock;
  26 +       struct buffer_head dummy;
  27 +       void *handle;
  28 +       int i, rc = 0, failed = 0, needed_blocks;
  29 +
  30 +       blocksize = inode->i_sb->s_blocksize;
  31 +       blocks_per_page = PAGE_SIZE >> inode->i_sb->s_blocksize_bits;
  32 +       iblock = page->index * blocks_per_page;
  33 +
  34 +       for (i = 0; i < blocks_per_page; i++, iblock++) {
  35 +               blocks[i] = ext4_bmap(inode->i_mapping, iblock);
  36 +               if (blocks[i] == 0) {
  37 +                       failed++;
  38 +               }
  39 +       }
  40 +
  41 +       if (failed == 0 || create == 0)
  42 +               return 0;
  43 +
  44 +       needed_blocks = ext4_writepage_trans_blocks(inode);
  45 +       handle = ext4_journal_start(inode, needed_blocks);
  46 +       if (IS_ERR(handle))
  47 +               return PTR_ERR(handle);
  48 +
  49 +       iblock = page->index * blocks_per_page;
  50 +       for (i = 0; i < blocks_per_page; i++, iblock++) {
  51 +               if (blocks[i] != 0)
  52 +                       continue;
  53 +
  54 +               rc = ext4_ind_get_blocks(handle, inode, iblock, 1, &dummy,
  55 +                                        EXT4_GET_BLOCKS_CREATE);
  56 +               if (rc < 0) {
  57 +                       printk(KERN_INFO "ext4_map_inode_page: error reading "
  58 +                                       "block %ld\n", iblock);
  59 +                       goto out;
  60 +               } else {
  61 +                       if (rc > 1)
  62 +                               WARN_ON(1);
  63 +                       rc = 0;
  64 +               }
  65 +               /* Unmap any metadata buffers from the block mapping, to avoid
  66 +                * data corruption due to direct-write from Lustre being
  67 +                * clobbered by a later flush of the blockdev metadata buffer.*/
  68 +               if (buffer_new(&dummy))
  69 +                       unmap_underlying_metadata(dummy.b_bdev,
  70 +                                       dummy.b_blocknr);
  71 +               blocks[i] = dummy.b_blocknr;
  72 +       }
  73 +
  74 +out:
  75 +       ext4_journal_stop(handle);
  76 +       return rc;
  77 +}
  78 +EXPORT_SYMBOL(ext4_map_inode_page);