Commit 0d8fee32 authored by Al Viro's avatar Al Viro Committed by Nathan Scott
Browse files

[XFS] Kill direct access to ->count in valusema(); all we ever use it for 


is check if semaphore is actually locked, which can be trivially done in
portable way. Code gets more reabable, while we are at it... 

SGI-PV: 953915
SGI-Modid: xfs-linux-melb:xfs-kern:26274a

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarNathan Scott <nathans@sgi.com>
parent a805bad5

fs/xfs/linux-2.6/sema.h

+10 −9
Original line number Diff line number Diff line
@@ -34,20 +34,21 @@ typedef struct semaphore sema_t; 
#define initnsema(sp, val, name)	sema_init(sp, val)

#define psema(sp, b)			down(sp)

#define vsema(sp)			up(sp)

#define valusema(sp)			(atomic_read(&(sp)->count))

#define freesema(sema)

#define freesema(sema)			do { } while (0)



static inline int issemalocked(sema_t *sp)

{

	return down_trylock(sp) || (up(sp), 0);

}



/*

 * Map cpsema (try to get the sema) to down_trylock. We need to switch

 * the return values since cpsema returns 1 (acquired) 0 (failed) and

 * down_trylock returns the reverse 0 (acquired) 1 (failed).

 */



#define cpsema(sp)			(down_trylock(sp) ? 0 : 1)



/*

 * Didn't do cvsema(sp). Not sure how to map this to up/down/...

 * It does a vsema if the values is < 0 other wise nothing.

 */

static inline int cpsema(sema_t *sp)

{

	return down_trylock(sp) ? 0 : 1;

}



#endif /* __XFS_SUPPORT_SEMA_H__ */

fs/xfs/quota/xfs_dquot.h

+2 −2
Original line number Diff line number Diff line
@@ -119,7 +119,7 @@ XFS_DQ_IS_LOCKED(xfs_dquot_t *dqp) 
 */

#define xfs_dqflock(dqp)	 { psema(&((dqp)->q_flock), PINOD | PRECALC);\

				   (dqp)->dq_flags |= XFS_DQ_FLOCKED; }

#define xfs_dqfunlock(dqp)	 { ASSERT(valusema(&((dqp)->q_flock)) <= 0); \

#define xfs_dqfunlock(dqp)	 { ASSERT(issemalocked(&((dqp)->q_flock))); \

				   vsema(&((dqp)->q_flock)); \

				   (dqp)->dq_flags &= ~(XFS_DQ_FLOCKED); }
@@ -128,7 +128,7 @@ XFS_DQ_IS_LOCKED(xfs_dquot_t *dqp) 
#define XFS_DQ_PINUNLOCK(dqp, s)   mutex_spinunlock( \

				     &(XFS_DQ_TO_QINF(dqp)->qi_pinlock), s)



#define XFS_DQ_IS_FLUSH_LOCKED(dqp) (valusema(&((dqp)->q_flock)) <= 0)

#define XFS_DQ_IS_FLUSH_LOCKED(dqp) (issemalocked(&((dqp)->q_flock)))

#define XFS_DQ_IS_ON_FREELIST(dqp)  ((dqp)->dq_flnext != (dqp))

#define XFS_DQ_IS_DIRTY(dqp)	((dqp)->dq_flags & XFS_DQ_DIRTY)

#define XFS_QM_ISUDQ(dqp)	((dqp)->dq_flags & XFS_DQ_USER)

fs/xfs/quota/xfs_dquot_item.c

+2 −2
Original line number Diff line number Diff line
@@ -248,7 +248,7 @@ xfs_qm_dquot_logitem_pushbuf( 
	 * inode flush completed and the inode was taken off the AIL.

	 * So, just get out.

	 */

	if ((valusema(&(dqp->q_flock)) > 0)  ||

	if (!issemalocked(&(dqp->q_flock))  ||

	    ((qip->qli_item.li_flags & XFS_LI_IN_AIL) == 0)) {

		qip->qli_pushbuf_flag = 0;

		xfs_dqunlock(dqp);
@@ -261,7 +261,7 @@ xfs_qm_dquot_logitem_pushbuf( 
	if (bp != NULL) {

		if (XFS_BUF_ISDELAYWRITE(bp)) {

			dopush = ((qip->qli_item.li_flags & XFS_LI_IN_AIL) &&

				  (valusema(&(dqp->q_flock)) <= 0));

				  issemalocked(&(dqp->q_flock)));

			qip->qli_pushbuf_flag = 0;

			xfs_dqunlock(dqp);

fs/xfs/xfs_iget.c

+1 −1
Original line number Diff line number Diff line
@@ -1031,6 +1031,6 @@ xfs_iflock_nowait(xfs_inode_t *ip) 
void

xfs_ifunlock(xfs_inode_t *ip)

{

	ASSERT(valusema(&(ip->i_flock)) <= 0);

	ASSERT(issemalocked(&(ip->i_flock)));

	vsema(&(ip->i_flock));

}

fs/xfs/xfs_inode.c

+2 −2
Original line number Diff line number Diff line
@@ -3015,7 +3015,7 @@ xfs_iflush( 
	XFS_STATS_INC(xs_iflush_count);



	ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE|MR_ACCESS));

	ASSERT(valusema(&ip->i_flock) <= 0);

	ASSERT(issemalocked(&(ip->i_flock)));

	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||

	       ip->i_d.di_nextents > ip->i_df.if_ext_max);
@@ -3273,7 +3273,7 @@ xfs_iflush_int( 
	SPLDECL(s);



	ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE|MR_ACCESS));

	ASSERT(valusema(&ip->i_flock) <= 0);

	ASSERT(issemalocked(&(ip->i_flock)));

	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||

	       ip->i_d.di_nextents > ip->i_df.if_ext_max);

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