Commit 79ada2ae authored by Tamir Duberstein's avatar Tamir Duberstein Committed by Andrew Morton
Browse files

xarray: extract helper from __xa_{insert,cmpxchg} 

Reduce code duplication by extracting a static inline function.  This
function is identical to __xa_cmpxchg with the exception that it does not
coerce zero entries to null on the return path.

[tamird@gmail.com: fix __xa_erase()]
  Link: https://lkml.kernel.org/r/CAJ-ks9kN_qddZ3Ne5d=cADu5POC1rHd4rQcbVSD_spnZOrLLZg@mail.gmail.com
Link: https://lkml.kernel.org/r/20241112-xarray-insert-cmpxchg-v1-2-dc2bdd8c4136@gmail.com


Signed-off-by: default avatarTamir Duberstein <tamird@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 74e2712b

lib/xarray.c

+19 −20
Original line number Diff line number Diff line
@@ -1491,7 +1491,7 @@ static void *xas_result(struct xa_state *xas, void *curr) 
{

	if (xas_error(xas))

		curr = xas->xa_node;

	return xa_zero_to_null(curr);

	return curr;

}



/**
@@ -1509,7 +1509,7 @@ static void *xas_result(struct xa_state *xas, void *curr) 
void *__xa_erase(struct xarray *xa, unsigned long index)

{

	XA_STATE(xas, xa, index);

	return xas_result(&xas, xas_store(&xas, NULL));

	return xas_result(&xas, xa_zero_to_null(xas_store(&xas, NULL)));

}

EXPORT_SYMBOL(__xa_erase);
@@ -1568,7 +1568,7 @@ void *__xa_store(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp) 
			xas_clear_mark(&xas, XA_FREE_MARK);

	} while (__xas_nomem(&xas, gfp));



	return xas_result(&xas, curr);

	return xas_result(&xas, xa_zero_to_null(curr));

}

EXPORT_SYMBOL(__xa_store);
@@ -1601,6 +1601,9 @@ void *xa_store(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp) 
}

EXPORT_SYMBOL(xa_store);



static inline void *__xa_cmpxchg_raw(struct xarray *xa, unsigned long index,

			void *old, void *entry, gfp_t gfp);



/**

 * __xa_cmpxchg() - Store this entry in the XArray.

 * @xa: XArray.
@@ -1619,6 +1622,13 @@ EXPORT_SYMBOL(xa_store); 
 */

void *__xa_cmpxchg(struct xarray *xa, unsigned long index,

			void *old, void *entry, gfp_t gfp)

{

	return xa_zero_to_null(__xa_cmpxchg_raw(xa, index, old, entry, gfp));

}

EXPORT_SYMBOL(__xa_cmpxchg);



static inline void *__xa_cmpxchg_raw(struct xarray *xa, unsigned long index,

			void *old, void *entry, gfp_t gfp)

{

	XA_STATE(xas, xa, index);

	void *curr;
@@ -1637,7 +1647,6 @@ void *__xa_cmpxchg(struct xarray *xa, unsigned long index, 


	return xas_result(&xas, curr);

}

EXPORT_SYMBOL(__xa_cmpxchg);



/**

 * __xa_insert() - Store this entry in the XArray if no entry is present.
@@ -1657,26 +1666,16 @@ EXPORT_SYMBOL(__xa_cmpxchg); 
 */

int __xa_insert(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp)

{

	XA_STATE(xas, xa, index);

	void *curr;

	int errno;



	if (WARN_ON_ONCE(xa_is_advanced(entry)))

		return -EINVAL;

	if (!entry)

		entry = XA_ZERO_ENTRY;



	do {

		curr = xas_load(&xas);

		if (!curr) {

			xas_store(&xas, entry);

			if (xa_track_free(xa))

				xas_clear_mark(&xas, XA_FREE_MARK);

		} else {

			xas_set_err(&xas, -EBUSY);

		}

	} while (__xas_nomem(&xas, gfp));



	return xas_error(&xas);

	curr = __xa_cmpxchg_raw(xa, index, NULL, entry, gfp);

	errno = xa_err(curr);

	if (errno)

		return errno;

	return (curr != NULL) ? -EBUSY : 0;

}

EXPORT_SYMBOL(__xa_insert);