linux.git/lib/xarray.c, branch v4.20-rc4

XArray: Correct xa_store_range

2018-11-16T21:27:28+00:00

The explicit '64' should have been BITS_PER_LONG, but while looking at
this code I realised I meant to use __ffs(), not ilog2().

Signed-off-by: Matthew Wilcox

XArray: Fix Documentation

2018-11-05T21:38:10+00:00

Minor fixes.

Signed-off-by: Matthew Wilcox

XArray: Handle NULL pointers differently for allocation

2018-11-05T21:38:09+00:00

For allocating XArrays, it makes sense to distinguish beteen erasing an
entry and storing NULL.  Storing NULL keeps the index allocated with a
NULL pointer associated with it while xa_erase() frees the index.  Some
existing IDR users rely on this ability.

Signed-off-by: Matthew Wilcox

XArray: Unify xa_store and __xa_store

2018-11-05T21:38:09+00:00

Saves around 115 bytes on a tinyconfig build and reduces the amount
of code duplication in the XArray implementation.

Signed-off-by: Matthew Wilcox

XArray: Turn xa_erase into an exported function

2018-11-05T21:38:09+00:00

Make xa_erase() take the spinlock and then call __xa_erase(), but make
it out of line since it's such a common function.

Signed-off-by: Matthew Wilcox

XArray: Unify xa_cmpxchg and __xa_cmpxchg

2018-11-05T21:38:08+00:00

xa_cmpxchg() was one of the largest functions in the xarray
implementation.  By turning it into a wrapper and having the callers
take the lock (like several other functions), we save 160 bytes on a
tinyconfig build and reduce the duplication in xarray.c.

Signed-off-by: Matthew Wilcox

XArray: Regularise xa_reserve

2018-11-05T21:38:08+00:00

The xa_reserve() function was a little unusual in that it attempted to
be callable for all kinds of locking scenarios.  Make it look like the
other APIs with __xa_reserve, xa_reserve_bh and xa_reserve_irq variants.

Signed-off-by: Matthew Wilcox

XArray: Export __xa_foo to non-GPL modules

2018-11-05T19:56:58+00:00

Without this, it's not possible to use static inlines like xa_store_bh()
and xa_erase_irq().

Signed-off-by: Matthew Wilcox

XArray: Fix xa_for_each with a single element at 0

2018-11-05T19:56:46+00:00

The following sequence of calls would result in an infinite loop in
xa_find_after():

	xa_store(xa, 0, x, GFP_KERNEL);
	index = 0;
	xa_for_each(xa, entry, index, ULONG_MAX, XA_PRESENT) { }

xa_find_after() was confusing the situation where we found no entry in
the tree with finding a multiorder entry, so it would look for the
successor entry forever.  Just check for this case explicitly.  Includes
a few new checks in the test suite to be sure this doesn't reappear.

Signed-off-by: Matthew Wilcox

xarray: Add range store functionality

2018-10-21T14:46:46+00:00

This version of xa_store_range() really only supports load and store.
Our only user only needs basic load and store functionality, so there's
no need to do the extra work to support marking and overlapping stores
correctly yet.

Signed-off-by: Matthew Wilcox