lustre/kernel_patches/patches/ext3-map_inode_page.patch

   1
   2
   3
   4  fs/ext3/ext3-exports.c |    3 ++
   5  fs/ext3/inode.c        |   55 +++++++++++++++++++++++++++++++++++++++++++++++++
   6  2 files changed, 58 insertions(+)
   7
   8 Index: lum/fs/ext3/inode.c
   9 ===================================================================
  10 --- lum.orig/fs/ext3/inode.c    Sat Nov 22 16:38:51 2003
  11 +++ lum/fs/ext3/inode.c Fri Nov 28 00:37:18 2003
  12 @@ -2979,3 +2979,80 @@
  13                 ret = ret2;
  14         return ret;
  15  }
  16 +
  17 +/* copied from fs/buffer.c */
  18 +static void unmap_underlying_metadata(struct buffer_head * bh)
  19 +{
  20 +       struct buffer_head *old_bh;
  21 +
  22 +       old_bh = get_hash_table(bh->b_dev, bh->b_blocknr, bh->b_size);
  23 +       if (old_bh) {
  24 +               mark_buffer_clean(old_bh);
  25 +               wait_on_buffer(old_bh);
  26 +               clear_bit(BH_Req, &old_bh->b_state);
  27 +               __brelse(old_bh);
  28 +       }
  29 +}
  30 +
  31 +int ext3_map_inode_page(struct inode *inode, struct page *page,
  32 +                        unsigned long *blocks, int *created, int create)
  33 +{
  34 +        unsigned int blocksize, blocks_per_page;
  35 +        unsigned long iblock;
  36 +        void *handle;
  37 +        int i, rc = 0, failed = 0, needed_blocks;
  38 +
  39 +        blocksize = inode->i_sb->s_blocksize;
  40 +        blocks_per_page = PAGE_SIZE >> inode->i_sb->s_blocksize_bits;
  41 +        iblock = page->index * blocks_per_page;
  42 +
  43 +        for (i = 0; i < blocks_per_page; i++, iblock++) {
  44 +                blocks[i] = ext3_bmap(inode->i_mapping, iblock);
  45 +                if (blocks[i] == 0) {
  46 +                        failed++;
  47 +                       if (created)
  48 +                               created[i] = -1;
  49 +               } else if (created) {
  50 +                       created[i] = 0;
  51 +                }
  52 +        }
  53 +
  54 +        if (failed == 0 || create == 0)
  55 +                return 0;
  56 +
  57 +        needed_blocks = ext3_writepage_trans_blocks(inode);
  58 +        lock_kernel();
  59 +        handle = ext3_journal_start(inode, needed_blocks);
  60 +        unlock_kernel();
  61 +        if (IS_ERR(handle))
  62 +                return PTR_ERR(handle);
  63 +
  64 +        iblock = page->index * blocks_per_page;
  65 +        for (i = 0; i < blocks_per_page; i++, iblock++) {
  66 +                struct buffer_head bh;
  67 +
  68 +                if (blocks[i] != 0)
  69 +                        continue;
  70 +
  71 +                rc = ext3_get_block_handle(handle, inode, iblock, &bh, 1);
  72 +                if (rc) {
  73 +                        printk(KERN_INFO "ext3_map_inode_page: error %d "
  74 +                               "allocating block %ld\n", rc, iblock);
  75 +                        goto out;
  76 +                }
  77 +               /* Unmap any metadata buffers from the block mapping, to avoid
  78 +                * data corruption due to direct-write from Lustre being
  79 +                * clobbered by a later flush of the blockdev metadata buffer.*/
  80 +                if (buffer_new(&bh))
  81 +                        unmap_underlying_metadata(&bh);
  82 +                blocks[i] = bh.b_blocknr;
  83 +               if (created)
  84 +                       created[i] = 1;
  85 +        }
  86 +
  87 + out:
  88 +       lock_kernel();
  89 +       ext3_journal_stop(handle, inode);
  90 +       unlock_kernel();
  91 +        return rc;
  92 +}
  93 Index: lum/fs/ext3/ext3-exports.c
  94 ===================================================================
  95 --- lum.orig/fs/ext3/ext3-exports.c     Sat Nov 22 16:38:51 2003
  96 +++ lum/fs/ext3/ext3-exports.c  Sat Nov 22 16:38:51 2003
  97 @@ -9,6 +9,8 @@
  98
  99  int ext3_prep_san_write(struct inode *inode, long *blocks,
 100                         int nblocks, loff_t newsize);
 101 +int ext3_map_inode_page(struct inode *inode, struct page *page,
 102 +                        unsigned long *block, int *created, int create);
 103
 104  EXPORT_SYMBOL(ext3_force_commit);
 105  EXPORT_SYMBOL(ext3_bread);
 106 @@ -18,3 +20,4 @@
 107  EXPORT_SYMBOL(ext3_xattr_list);
 108  EXPORT_SYMBOL(ext3_xattr_set);
 109  EXPORT_SYMBOL(ext3_prep_san_write);
 110 +EXPORT_SYMBOL(ext3_map_inode_page);