[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>

6 files changed, 20 insertions, 19 deletions

diff --git a/fs/xfs/linux-2.6/sema.h b/fs/xfs/linux-2.6/sema.h
index 194a844..b250900 100644
--- a/fs/xfs/linux-2.6/sema.h
+++ b/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__ */
diff --git a/fs/xfs/quota/xfs_dquot.h b/fs/xfs/quota/xfs_dquot.h
index c0c6296..78d3ab9 100644
--- a/fs/xfs/quota/xfs_dquot.h
+++ b/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)
diff --git a/fs/xfs/quota/xfs_dquot_item.c b/fs/xfs/quota/xfs_dquot_item.c
index 546f48a..21ad5a5 100644
--- a/fs/xfs/quota/xfs_dquot_item.c
+++ b/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);
 
diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c
index da3c94c..7894b72 100644
--- a/fs/xfs/xfs_iget.c
+++ b/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));
 }
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 9af9e32..e799f0d 100644
--- a/fs/xfs/xfs_inode.c
+++ b/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);
 
diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
index cd65a56..2caa91b 100644
--- a/fs/xfs/xfs_inode_item.c
+++ b/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