return error;
}
+
+/*
+ * Try to lock an inode in violation of the usual locking order rules. For
+ * example, trying to get the IOLOCK while in transaction context, or just
+ * plain breaking AG-order or inode-order inode locking rules. Either way,
+ * the only way to avoid an ABBA deadlock is to use trylock and back off if
+ * we can't.
+ */
+int
+xfs_scrub_ilock_inverted(
+ struct xfs_inode *ip,
+ uint lock_mode)
+{
+ int i;
+
+ for (i = 0; i < 20; i++) {
+ if (xfs_ilock_nowait(ip, lock_mode))
+ return 0;
+ delay(1);
+ }
+ return -EDEADLOCK;
+}
}
int xfs_scrub_metadata_inode_forks(struct xfs_scrub_context *sc);
+int xfs_scrub_ilock_inverted(struct xfs_inode *ip, uint lock_mode);
#endif /* __XFS_SCRUB_COMMON_H__ */
*/
xfs_iunlock(sc->ip, sc->ilock_flags);
sc->ilock_flags = 0;
- xfs_ilock(dp, XFS_IOLOCK_SHARED);
+ error = xfs_scrub_ilock_inverted(dp, XFS_IOLOCK_SHARED);
+ if (error)
+ goto out_rele;
/* Go looking for our dentry. */
error = xfs_scrub_parent_count_parent_dentries(sc, dp, &nlink);
/* Drop the parent lock, relock this inode. */
xfs_iunlock(dp, XFS_IOLOCK_SHARED);
+ error = xfs_scrub_ilock_inverted(sc->ip, XFS_IOLOCK_EXCL);
+ if (error)
+ goto out_rele;
sc->ilock_flags = XFS_IOLOCK_EXCL;
- xfs_ilock(sc->ip, sc->ilock_flags);
/*
* If we're an unlinked directory, the parent /won't/ have a link
if (try_again && tries == 20)
xfs_scrub_set_incomplete(sc);
out:
+ /*
+ * If we failed to lock the parent inode even after a retry, just mark
+ * this scrub incomplete and return.
+ */
+ if (sc->try_harder && error == -EDEADLOCK) {
+ error = 0;
+ xfs_scrub_set_incomplete(sc);
+ }
return error;
}