- int stale_buf = 1;
-
- /*
- * Scan through the on-disk inode buffer and attempt to
- * determine if it has been written to since it was logged.
- *
- * - If any of the magic numbers are incorrect then the buffer is stale
- * - If any of the modes are non-zero then the buffer is not stale
- * - If all of the modes are zero and at least one of the generation
- * counts is non-zero then the buffer is stale
- *
- * If the end result is a stale buffer then the log buffer is replayed
- * otherwise it is skipped.
- *
- * This heuristic is not perfect. It can be improved by scanning the
- * entire inode chunk for evidence that any of the inode clusters have
- * been updated. To fix this problem completely we will need a major
- * architectural change to the logging system.
- */
- if (buf_f->blf_flags & XFS_BLI_INODE_NEW_BUF) {
- xfs_dinode_t *dip;
- int inodes_per_buf;
- int mode_count = 0;
- int gen_count = 0;
-
- stale_buf = 0;
- inodes_per_buf = XFS_BUF_COUNT(bp) >> mp->m_sb.sb_inodelog;
- for (i = 0; i < inodes_per_buf; i++) {
- dip = (xfs_dinode_t *)xfs_buf_offset(bp,
- i * mp->m_sb.sb_inodesize);
- if (be16_to_cpu(dip->di_core.di_magic) !=
- XFS_DINODE_MAGIC) {
- stale_buf = 1;
- break;
- }
- if (dip->di_core.di_mode)
- mode_count++;
- if (dip->di_core.di_gen)
- gen_count++;
- }
-
- if (!mode_count && gen_count)
- stale_buf = 1;
- }