lustre/kernel_patches/patches/ext3-map_inode_page_2.4.18.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: linux-2.4.18-p4smp/fs/ext3/ext3-exports.c
   9 ===================================================================
  10 --- linux-2.4.18-p4smp.orig/fs/ext3/ext3-exports.c      Thu Nov 27 22:18:40 2003
  11 +++ linux-2.4.18-p4smp/fs/ext3/ext3-exports.c   Thu Nov 27 22:18:40 2003
  12 @@ -9,6 +9,8 @@
  13
  14  int ext3_prep_san_write(struct inode *inode, long *blocks,
  15                         int nblocks, loff_t newsize);
  16 +int ext3_map_inode_page(struct inode *inode, struct page *page,
  17 +                        unsigned long *block, int *created, int create);
  18
  19  EXPORT_SYMBOL(ext3_force_commit);
  20  EXPORT_SYMBOL(ext3_bread);
  21 @@ -18,3 +20,4 @@
  22  EXPORT_SYMBOL(ext3_xattr_list);
  23  EXPORT_SYMBOL(ext3_xattr_set);
  24  EXPORT_SYMBOL(ext3_prep_san_write);
  25 +EXPORT_SYMBOL(ext3_map_inode_page);
  26 Index: linux-2.4.18-p4smp/fs/ext3/inode.c
  27 ===================================================================
  28 --- linux-2.4.18-p4smp.orig/fs/ext3/inode.c     Thu Nov 27 22:18:40 2003
  29 +++ linux-2.4.18-p4smp/fs/ext3/inode.c  Thu Nov 27 22:20:36 2003
  30 @@ -3004,3 +3004,80 @@
  31                 ret = ret2;
  32         return ret;
  33  }
  34 +
  35 +/* copied from fs/buffer.c */
  36 +static void unmap_underlying_metadata(struct buffer_head * bh)
  37 +{
  38 +       struct buffer_head *old_bh;
  39 +
  40 +       old_bh = get_hash_table(bh->b_dev, bh->b_blocknr, bh->b_size);
  41 +       if (old_bh) {
  42 +               mark_buffer_clean(old_bh);
  43 +               wait_on_buffer(old_bh);
  44 +               clear_bit(BH_Req, &old_bh->b_state);
  45 +               __brelse(old_bh);
  46 +       }
  47 +}
  48 +
  49 +int ext3_map_inode_page(struct inode *inode, struct page *page,
  50 +                        unsigned long *blocks, int *created, int create)
  51 +{
  52 +        unsigned int blocksize, blocks_per_page;
  53 +        unsigned long iblock;
  54 +        void *handle;
  55 +        int i, rc = 0, failed = 0, needed_blocks;
  56 +
  57 +        blocksize = inode->i_sb->s_blocksize;
  58 +        blocks_per_page = PAGE_SIZE >> inode->i_sb->s_blocksize_bits;
  59 +        iblock = page->index * blocks_per_page;
  60 +
  61 +        for (i = 0; i < blocks_per_page; i++, iblock++) {
  62 +                blocks[i] = ext3_bmap(inode->i_mapping, iblock);
  63 +                if (blocks[i] == 0) {
  64 +                        failed++;
  65 +                       if (created)
  66 +                               created[i] = -1;
  67 +               } else if (created) {
  68 +                        created[i] = 0;
  69 +                }
  70 +        }
  71 +
  72 +        if (failed == 0 || create == 0)
  73 +                return 0;
  74 +
  75 +        needed_blocks = ext3_writepage_trans_blocks(inode);
  76 +        lock_kernel();
  77 +        handle = ext3_journal_start(inode, needed_blocks);
  78 +        unlock_kernel();
  79 +        if (IS_ERR(handle))
  80 +                return PTR_ERR(handle);
  81 +
  82 +        iblock = page->index * blocks_per_page;
  83 +        for (i = 0; i < blocks_per_page; i++, iblock++) {
  84 +                struct buffer_head bh;
  85 +
  86 +                if (blocks[i] != 0)
  87 +                        continue;
  88 +
  89 +                rc = ext3_get_block_handle(handle, inode, iblock, &bh, 1);
  90 +                if (rc) {
  91 +                        printk(KERN_INFO "ext3_map_inode_page: error %d "
  92 +                               "allocating block %ld\n", rc, iblock);
  93 +                        goto out;
  94 +                }
  95 +               /* Unmap any metadata buffers from the block mapping, to avoid
  96 +                * data corruption due to direct-write from Lustre being
  97 +                * clobbered by a later flush of the blockdev metadata buffer.*/
  98 +                if (buffer_new(&bh))
  99 +                        unmap_underlying_metadata(&bh);
 100 +                blocks[i] = bh.b_blocknr;
 101 +               if (created)
 102 +                       created[i] = 1;
 103 +        }
 104 +
 105 + out:
 106 +       lock_kernel();
 107 +       ext3_journal_stop(handle, inode);
 108 +       unlock_kernel();
 109 +        return rc;
 110 +}