1 files changed, 83 insertions, 1 deletions

diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c
index f136639f5b41..ca4ab7ce85bf 100644
--- a/fs/ocfs2/buffer_head_io.c
+++ b/fs/ocfs2/buffer_head_io.c
@@ -66,7 +66,7 @@ int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh,
         /* remove from dirty list before I/O. */
         clear_buffer_dirty(bh);
 
-        get_bh(bh); /* for end_buffer_write_sync() */                   
+        get_bh(bh); /* for end_buffer_write_sync() */
         bh->b_end_io = end_buffer_write_sync;
         submit_bh(WRITE, bh);
 
@@ -88,6 +88,88 @@ out:
         return ret;
 }
 
+int ocfs2_read_blocks_sync(struct ocfs2_super *osb, u64 block,
+                           unsigned int nr, struct buffer_head *bhs[])
+{
+        int status = 0;
+        unsigned int i;
+        struct buffer_head *bh;
+
+        if (!nr) {
+                mlog(ML_BH_IO, "No buffers will be read!\n");
+                goto bail;
+        }
+
+        for (i = 0 ; i < nr ; i++) {
+                if (bhs[i] == NULL) {
+                        bhs[i] = sb_getblk(osb->sb, block++);
+                        if (bhs[i] == NULL) {
+                                status = -EIO;
+                                mlog_errno(status);
+                                goto bail;
+                        }
+                }
+                bh = bhs[i];
+
+                if (buffer_jbd(bh)) {
+                        mlog(ML_ERROR,
+                             "trying to sync read a jbd "
+                             "managed bh (blocknr = %llu), skipping\n",
+                             (unsigned long long)bh->b_blocknr);
+                        continue;
+                }
+
+                if (buffer_dirty(bh)) {
+                        /* This should probably be a BUG, or
+                         * at least return an error. */
+                        mlog(ML_ERROR,
+                             "trying to sync read a dirty "
+                             "buffer! (blocknr = %llu), skipping\n",
+                             (unsigned long long)bh->b_blocknr);
+                        continue;
+                }
+
+                lock_buffer(bh);
+                if (buffer_jbd(bh)) {
+                        mlog(ML_ERROR,
+                             "block %llu had the JBD bit set "
+                             "while I was in lock_buffer!",
+                             (unsigned long long)bh->b_blocknr);
+                        BUG();
+                }
+
+                clear_buffer_uptodate(bh);
+                get_bh(bh); /* for end_buffer_read_sync() */
+                bh->b_end_io = end_buffer_read_sync;
+                submit_bh(READ, bh);
+        }
+
+        for (i = nr; i > 0; i--) {
+                bh = bhs[i - 1];
+
+                if (buffer_jbd(bh)) {
+                        mlog(ML_ERROR,
+                             "the journal got the buffer while it was "
+                             "locked for io! (blocknr = %llu)\n",
+                             (unsigned long long)bh->b_blocknr);
+                        BUG();
+                }
+
+                wait_on_buffer(bh);
+                if (!buffer_uptodate(bh)) {
+                        /* Status won't be cleared from here on out,
+                         * so we can safely record this and loop back
+                         * to cleanup the other buffers. */
+                        status = -EIO;
+                        put_bh(bh);
+                        bhs[i - 1] = NULL;
+                }
+        }
+
+bail:
+        return status;
+}
+
 int ocfs2_read_blocks(struct ocfs2_super *osb, u64 block, int nr,
                       struct buffer_head *bhs[], int flags,
                       struct inode *inode)