It is not necessary to take the lock and search through the request list
if the list is empty.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>

Otherwise lockdep says:

[ 1337.483798] ================================================
[ 1337.483999] [ BUG: lock held when returning to user space! ]
[ 1337.484252] 4.11.0-rc6 #19 Not tainted
[ 1337.484423] ------------------------------------------------
[ 1337.484626] mount/14766 is leaving the kernel with locks still held!
[ 1337.484841] 1 lock held by mount/14766:
[ 1337.485017]  #0:  (&type->s_umount_key#33/1){+.+.+.}, at: [<ffffffff8124171f>] sget_userns+0x2af/0x520

Caught by xfstests generic/413 which tried to mount with the unsupported
mount option dax.  Then xfstests generic/422 ran sync which deadlocks.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Acked-by: Mike Marshall <hubcap@omnibond.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Linux 4.10

This patch is simlar to one Dan Carpenter sent me, cleans
up some return codes and whitespace errors. There was one
place where he thought inserting an error message into
the ring buffer might be too chatty, I hope I convinced him
othewise. As a consolation <g> I changed a truly chatty
error message in another location into a debug message,
system-admins had already yelled at me about that one...

Signed-off-by: Mike Marshall <hubcap@omnibond.com>

copy_from_iter_full(), copy_from_iter_full_nocache() and
csum_and_copy_from_iter_full() - counterparts of copy_from_iter()
et.al., advancing iterator only in case of successful full copy
and returning whether it had been successful or not.

Convert some obvious users.  *NOTE* - do not blindly assume that
something is a good candidate for those unless you are sure that
not advancing iov_iter in failure case is the right thing in
this case.  Anything that does short read/short write kind of
stuff (or is in a loop, etc.) is unlikely to be a good one.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull in an OrangeFS branch containing miscellaneous improvements.

- clean up debugfs globals
- remove dead code in sysfs
- reorganize duplicated sysfs attribute structs
- consolidate sysfs show and store functions
- remove duplicated sysfs_ops structures
- describe organization of sysfs
- make devreq_mutex static
- g_orangefs_stats -> orangefs_stats for consistency
- rename most remaining global variables

Only op_timeout_secs, slot_timeout_secs, and hash_table_size are left
because they are exposed as module parameters. All other global
variables have the orangefs_ prefix.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>

Signed-off-by: Martin Brandenburg <martin@omnibond.com>

Mostly this is moving code into orangefs-debugfs.c so that globals turn
into static globals.

Then gossip_debug_mask is renamed orangefs_gossip_debug_mask but keeps
global visibility, so it can be used from a macro.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>

This is a new userspace operation, which will be done if the client-core
version is greater than or equal to 2.9.6. This will provide a way to
implement optional features and to determine which features are
supported by the client-core. If the client-core version is older than
2.9.6, no optional features are supported and the op will not be done.

The intent is to allow protocol extensions without relying on the
client-core's current behavior of ignoring what it doesn't understand.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>