Commit 64252c75a removed the useless dget from dentry_unhash but didn't
fix up this caller in the usb code.  There used to be exactly one dput per
dentry_unhash call; now there are none.

Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

dcache_lock no longer protects anything. remove it.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

Protect d_subdirs and d_child with d_lock, except in filesystems that aren't
using dcache_lock for these anyway (eg. using i_mutex).

Note: if we change the locking rule in future so that ->d_child protection is
provided only with ->d_parent->d_lock, it may allow us to reduce some locking.
But it would be an exception to an otherwise regular locking scheme, so we'd
have to see some good results. Probably not worthwhile.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

Protect d_unhashed(dentry) condition with d_lock. This means keeping
DCACHE_UNHASHED bit in synch with hash manipulations.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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

Instead of always assigning an increasing inode number in new_inode
move the call to assign it into those callers that actually need it.
For now callers that need it is estimated conservatively, that is
the call is added to all filesystems that do not assign an i_ino
by themselves.  For a few more filesystems we can avoid assigning
any inode number given that they aren't user visible, and for others
it could be done lazily when an inode number is actually needed,
but that's left for later patches.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The code this is attempting to lock against does not use the BKL,
so it's not needed.

Most likely this code is still broken/racy (Al Viro also thinks so),
but removing the BKL should not make it worse than before.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

The usbcore headers: hcd.h and hub.h are shared between usbcore,
HCDs and a couple of other drivers (e.g. USBIP modules).
So, it makes sense to move them into a more public location and
to cleanup dependency of those modules on kernel internal headers.
This patch moves hcd.h from drivers/usb/core into include/linux/usb/

Signed-of-by: Eric Lescouet <eric@lescouet.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1) i_flags simply doesn't work for mount/unlink race prevention;
we may have many links to file and rm on one of those obviously
shouldn't prevent bind on top of another later on.  To fix it
right way we need to mark _dentry_ as unsuitable for mounting
upon; new flag (DCACHE_CANT_MOUNT) is protected by d_flags and
i_mutex on the inode in question.  Set it (with dont_mount(dentry))
in unlink/rmdir/etc., check (with cant_mount(dentry)) in places
in namespace.c that used to check for S_DEAD.  Setting S_DEAD
is still needed in places where we used to set it (for directories
getting killed), since we rely on it for readdir/rmdir race
prevention.

2) rename()/mount() protection has another bogosity - we unhash
the target before we'd checked that it's not a mountpoint.  Fixed.

3) ancient bogosity in pivot_root() - we locked i_mutex on the
right directory, but checked S_DEAD on the different (and wrong)
one.  Noticed and fixed.

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