ext4: don't read blocks from disk after extents being swapped

[cascardo/linux.git] / fs / ext4 / move_extent.c

diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index fb6f117..e032a04 100644 (file)
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -265,11 +265,12 @@ move_extent_per_page(struct file *o_filp, struct inode *donor_inode,
        ext4_lblk_t orig_blk_offset, donor_blk_offset;
        unsigned long blocksize = orig_inode->i_sb->s_blocksize;
        unsigned int tmp_data_size, data_size, replaced_size;
-       int err2, jblocks, retries = 0;
+       int i, err2, jblocks, retries = 0;
        int replaced_count = 0;
        int from = data_offset_in_page << orig_inode->i_blkbits;
        int blocks_per_page = PAGE_CACHE_SIZE >> orig_inode->i_blkbits;
        struct super_block *sb = orig_inode->i_sb;
+       struct buffer_head *bh = NULL;
 
        /*
         * It needs twice the amount of ordinary journal buffers because
@@ -380,8 +381,16 @@ data_copy:
        }
        /* Perform all necessary steps similar write_begin()/write_end()
         * but keeping in mind that i_size will not change */
-       *err = __block_write_begin(pagep[0], from, replaced_size,
-                                  ext4_get_block);
+       if (!page_has_buffers(pagep[0]))
+               create_empty_buffers(pagep[0], 1 << orig_inode->i_blkbits, 0);
+       bh = page_buffers(pagep[0]);
+       for (i = 0; i < data_offset_in_page; i++)
+               bh = bh->b_this_page;
+       for (i = 0; i < block_len_in_page; i++) {
+               *err = ext4_get_block(orig_inode, orig_blk_offset + i, bh, 0);
+               if (*err < 0)
+                       break;
+       }
        if (!*err)
                *err = block_commit_write(pagep[0], from, from + replaced_size);