After some additional testing on version 2, I realized that 1) my test setup was bad (Doh!) and 2) using remount isn't really an ideal method for setting the "serverfailed" mount flag. The reason being that any userspace remount is going to touch the file system and probably invoke some RPCs for inode validation as such. If the server is truly dead, these RPCs will have to time out before the flag could actually be set. This not only takes a long time, but will probably also fail, causing the remount to fail and not set the flag, defeating the purpose. This patch set works around this by exposing the failed server flag in debugfs. In addition, the flag now applies at the nfs_client level (instead of the nfs_server). Setting the flag will cancel all RPCs in the client, as well as all nfs_servers attached to it. This ensures that you get all the mounts, even when dealing with submounts that cross remote device boundaries. This is also where the nosharecache option applying to nfs_clients becomes useful... it will prevent sharing between other explicit mount calls, but submounts will all still share a nfs_client (and fail together). Obviously, debugfs is not a permanent solution for this, so some discussion needs to be had on how this will be administered "in the real world" (I think "remount" is off the table). Joshua Watt (7): SUNRPC: Add flag to kill new tasks SUNRPC: Expose kill_new_tasks in debugfs SUNRPC: Simplify client shutdown NFS: Add debugfs for nfs_server and nfs_client NFS: Propagate NFS_MOUNT_UNSHARED to clients NFS: Add API to fail client NFS: Control failed clients through debugfs fs/nfs/Makefile | 2 +- fs/nfs/client.c | 121 ++++++++++++++++++++++++-- fs/nfs/debugfs.c | 202 ++++++++++++++++++++++++++++++++++++++++++++ fs/nfs/inode.c | 5 ++ fs/nfs/internal.h | 11 +++ fs/nfs/nfs3client.c | 2 + fs/nfs/nfs4client.c | 5 ++ include/linux/nfs_fs_sb.h | 8 ++ include/linux/sunrpc/clnt.h | 1 + net/sunrpc/clnt.c | 12 +-- net/sunrpc/debugfs.c | 4 + net/sunrpc/sched.c | 3 + 12 files changed, 360 insertions(+), 16 deletions(-) create mode 100644 fs/nfs/debugfs.c -- 2.13.6 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
