[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: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Nathan Scott <nathans@sgi.com>

fs/xfs/linux-2.6/sema.h

@@ -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

@@ -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

@@ -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

@@ -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

@@ -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);
 

fs/xfs/xfs_inode_item.c

@@ -794,7 +794,7 @@ xfs_inode_item_pushbuf(
 	 * inode flush completed and the inode was taken off the AIL.
 	 * So, just get out.
 	 */
-	if ((valusema(&(ip->i_flock)) > 0)  ||
+	if (!issemalocked(&(ip->i_flock)) ||
 	    ((iip->ili_item.li_flags & XFS_LI_IN_AIL) == 0)) {
 		iip->ili_pushbuf_flag = 0;
 		xfs_iunlock(ip, XFS_ILOCK_SHARED);
@@ -816,7 +816,7 @@ xfs_inode_item_pushbuf(
 			 * If not, we can flush it async.
 			 */
 			dopush = ((iip->ili_item.li_flags & XFS_LI_IN_AIL) &&
-				  (valusema(&(ip->i_flock)) <= 0));
+				  issemalocked(&(ip->i_flock)));
 			iip->ili_pushbuf_flag = 0;
 			xfs_iunlock(ip, XFS_ILOCK_SHARED);
 			xfs_buftrace("INODE ITEM PUSH", bp);
@@ -864,7 +864,7 @@ xfs_inode_item_push(
 	ip = iip->ili_inode;
 
 	ASSERT(ismrlocked(&(ip->i_lock), MR_ACCESS));
-	ASSERT(valusema(&(ip->i_flock)) <= 0);
+	ASSERT(issemalocked(&(ip->i_flock)));
 	/*
 	 * Since we were able to lock the inode's flush lock and
 	 * we found it on the AIL, the inode must be dirty.  This