tree 158b3aabf291ef9462e3e02493fb4c45265f9e8e
parent 1356b8c28d67cafd74f7e7dcfb39bf53681790a5
author Chuck Lever <cel@netapp.com> 1142880252 -0500
committer Trond Myklebust <Trond.Myklebust@netapp.com> 1142880252 -0500

VFS: New /proc file /proc/self/mountstats

Create a new file under /proc/self, called mountstats, where mounted file
systems can export information (configuration options, performance counters,
and so on).  Use a mechanism similar to /proc/mounts and s_ops->show_options.

This mechanism does not violate namespace security, and is safe to use while
other processes are unmounting file systems.

Thanks to Mike Waychison for his review and comments.

Test-plan:
Test concurrent mount/unmount operations while cat'ing /proc/self/mountstats.

Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>