tree 88c92721b67434a5ae982956cb5f300a6bcd8297
parent 7935799e041ae10d380d04ea23868240f082bd11
author Paulo Alcantara (SUSE) <pc@cjr.nz> 1576703497 -0300
committer Steve French <stfrench@microsoft.com> 1577113484 -0600

cifs: Optimize readdir on reparse points

When listing a directory with thounsands of files and most of them are
reparse points, we simply marked all those dentries for revalidation
and then sending additional (compounded) create/getinfo/close requests
for each of them.

Instead, upon receiving a response from an SMB2_QUERY_DIRECTORY
(FileIdFullDirectoryInformation) command, the directory entries that
have a file attribute of FILE_ATTRIBUTE_REPARSE_POINT will contain an
EaSize field with a reparse tag in it, so we parse it and mark the
dentry for revalidation only if it is a DFS or a symlink.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>