tree b5486f7b0f12abf9ed670d187f4841dfdb2aa13e
parent b459be739f97e2062b2ba77cfe8ea198dbd58904
author Yan, Zheng <zyan@redhat.com> 1434458936 +0800
committer Ilya Dryomov <idryomov@gmail.com> 1435222172 +0300

ceph: rework dcache readdir

Previously our dcache readdir code relies on that child dentries in
directory dentry's d_subdir list are sorted by dentry's offset in
descending order. When adding dentries to the dcache, if a dentry
already exists, our readdir code moves it to head of directory
dentry's d_subdir list. This design relies on dcache internals.
Al Viro suggests using ncpfs's approach: keeping array of pointers
to dentries in page cache of directory inode. the validity of those
pointers are presented by directory inode's complete and ordered
flags. When a dentry gets pruned, we clear directory inode's complete
flag in the d_prune() callback. Before moving a dentry to other
directory, we clear the ordered flag for both old and new directory.

Signed-off-by: Yan, Zheng <zyan@redhat.com>