tree 9eec0813194dd2192f6ae05d2f344e7839d2ab44
parent b4d693fcc5fe99ed211addb5c6a0f8398f0b266e
author Goldwyn Rodrigues <rgoldwyn@gmail.com> 1277737472 -0500
committer Joel Becker <joel.becker@oracle.com> 1284135495 -0700

Track negative entries v3

Track negative dentries by recording the generation number of the parent
directory in d_fsdata. The generation number for the parent directory is
recorded in the inode_info, which increments every time the lock on the
directory is dropped.

If the generation number of the parent directory and the negative dentry
matches, there is no need to perform the revalidate, else a revalidate
is forced. This improves performance in situations where nodes look for
the same non-existent file multiple times.

Thanks Mark for explaining the DLM sequence.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.de>
Signed-off-by: Joel Becker <joel.becker@oracle.com>