Commit 3b583adf authored by Fedor Pchelkin's avatar Fedor Pchelkin Committed by Carlos Maiolino
Browse files

xfs: refactor cmp_two_keys routines to take advantage of cmp_int() 



The net value of these functions is to determine the result of a
three-way-comparison between operands of the same type.

Simplify the code using cmp_int() to eliminate potential errors with
opencoded casts and subtractions. This also means we can change the return
value type of cmp_two_keys routines from int64_t to int and make the
interface a bit clearer.

Found by Linux Verification Center (linuxtesting.org).

Suggested-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarFedor Pchelkin <pchelkin@ispras.ru>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarCarlos Maiolino <cem@kernel.org>
parent 82b63ee1

fs/xfs/libxfs/xfs_alloc_btree.c

+8 −13
Original line number Diff line number Diff line
@@ -213,7 +213,7 @@ xfs_cntbt_cmp_key_with_cur( 
	return (int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;

}



STATIC int64_t

STATIC int

xfs_bnobt_cmp_two_keys(

	struct xfs_btree_cur		*cur,

	const union xfs_btree_key	*k1,
@@ -222,29 +222,24 @@ xfs_bnobt_cmp_two_keys( 
{

	ASSERT(!mask || mask->alloc.ar_startblock);



	return (int64_t)be32_to_cpu(k1->alloc.ar_startblock) -

			be32_to_cpu(k2->alloc.ar_startblock);

	return cmp_int(be32_to_cpu(k1->alloc.ar_startblock),

		       be32_to_cpu(k2->alloc.ar_startblock));

}



STATIC int64_t

STATIC int

xfs_cntbt_cmp_two_keys(

	struct xfs_btree_cur		*cur,

	const union xfs_btree_key	*k1,

	const union xfs_btree_key	*k2,

	const union xfs_btree_key	*mask)

{

	int64_t				diff;



	ASSERT(!mask || (mask->alloc.ar_blockcount &&

			 mask->alloc.ar_startblock));



	diff =  be32_to_cpu(k1->alloc.ar_blockcount) -

		be32_to_cpu(k2->alloc.ar_blockcount);

	if (diff)

		return diff;



	return  be32_to_cpu(k1->alloc.ar_startblock) -

		be32_to_cpu(k2->alloc.ar_startblock);

	return cmp_int(be32_to_cpu(k1->alloc.ar_blockcount),

		       be32_to_cpu(k2->alloc.ar_blockcount)) ?:

	       cmp_int(be32_to_cpu(k1->alloc.ar_startblock),

		       be32_to_cpu(k2->alloc.ar_startblock));

}



static xfs_failaddr_t

fs/xfs/libxfs/xfs_bmap_btree.c

+3 −15
Original line number Diff line number Diff line
@@ -378,29 +378,17 @@ xfs_bmbt_cmp_key_with_cur( 
				      cur->bc_rec.b.br_startoff;

}



STATIC int64_t

STATIC int

xfs_bmbt_cmp_two_keys(

	struct xfs_btree_cur		*cur,

	const union xfs_btree_key	*k1,

	const union xfs_btree_key	*k2,

	const union xfs_btree_key	*mask)

{

	uint64_t			a = be64_to_cpu(k1->bmbt.br_startoff);

	uint64_t			b = be64_to_cpu(k2->bmbt.br_startoff);



	ASSERT(!mask || mask->bmbt.br_startoff);



	/*

	 * Note: This routine previously casted a and b to int64 and subtracted

	 * them to generate a result.  This lead to problems if b was the

	 * "maximum" key value (all ones) being signed incorrectly, hence this

	 * somewhat less efficient version.

	 */

	if (a > b)

		return 1;

	if (b > a)

		return -1;

	return 0;

	return cmp_int(be64_to_cpu(k1->bmbt.br_startoff),

		       be64_to_cpu(k2->bmbt.br_startoff));

}



static xfs_failaddr_t

fs/xfs/libxfs/xfs_btree.h

+1 −1
Original line number Diff line number Diff line
@@ -184,7 +184,7 @@ struct xfs_btree_ops { 
	 * each key field to be used in the comparison must contain a nonzero

	 * value.

	 */

	int64_t (*cmp_two_keys)(struct xfs_btree_cur *cur,

	int	(*cmp_two_keys)(struct xfs_btree_cur *cur,

				const union xfs_btree_key *key1,

				const union xfs_btree_key *key2,

				const union xfs_btree_key *mask);

fs/xfs/libxfs/xfs_ialloc_btree.c

+3 −3
Original line number Diff line number Diff line
@@ -274,7 +274,7 @@ xfs_inobt_cmp_key_with_cur( 
			  cur->bc_rec.i.ir_startino;

}



STATIC int64_t

STATIC int

xfs_inobt_cmp_two_keys(

	struct xfs_btree_cur		*cur,

	const union xfs_btree_key	*k1,
@@ -283,8 +283,8 @@ xfs_inobt_cmp_two_keys( 
{

	ASSERT(!mask || mask->inobt.ir_startino);



	return (int64_t)be32_to_cpu(k1->inobt.ir_startino) -

			be32_to_cpu(k2->inobt.ir_startino);

	return cmp_int(be32_to_cpu(k1->inobt.ir_startino),

		       be32_to_cpu(k2->inobt.ir_startino));

}



static xfs_failaddr_t

fs/xfs/libxfs/xfs_refcount_btree.c

+3 −3
Original line number Diff line number Diff line
@@ -188,7 +188,7 @@ xfs_refcountbt_cmp_key_with_cur( 
	return (int64_t)be32_to_cpu(kp->rc_startblock) - start;

}



STATIC int64_t

STATIC int

xfs_refcountbt_cmp_two_keys(

	struct xfs_btree_cur		*cur,

	const union xfs_btree_key	*k1,
@@ -197,8 +197,8 @@ xfs_refcountbt_cmp_two_keys( 
{

	ASSERT(!mask || mask->refc.rc_startblock);



	return (int64_t)be32_to_cpu(k1->refc.rc_startblock) -

			be32_to_cpu(k2->refc.rc_startblock);

	return cmp_int(be32_to_cpu(k1->refc.rc_startblock),

		       be32_to_cpu(k2->refc.rc_startblock));

}



STATIC xfs_failaddr_t