JFS: prevent concurrent calls to txCommit on the imap inode

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>

fs/jfs/jfs_imap.c

@@ -1280,6 +1280,7 @@ int diFree(struct inode *ip)
 	 * to be freed by the transaction;  
 	 */
 	tid = txBegin(ipimap->i_sb, COMMIT_FORCE);
+	down(&JFS_IP(ipimap)->commit_sem);
 
 	/* acquire tlock of the iag page of the freed ixad 
 	 * to force the page NOHOMEOK (even though no data is
@@ -1312,6 +1313,7 @@ int diFree(struct inode *ip)
 	rc = txCommit(tid, 1, &iplist[0], COMMIT_FORCE);
 
 	txEnd(tid);
+	up(&JFS_IP(ipimap)->commit_sem);
 
 	/* unlock the AG inode map information */
 	AG_UNLOCK(imap, agno);
@@ -2622,10 +2624,13 @@ diNewIAG(struct inomap * imap, int *iagnop, int agno, struct metapage ** mpp)
 		 */
 #endif				/*  _STILL_TO_PORT */
 		tid = txBegin(sb, COMMIT_FORCE);
+		down(&JFS_IP(ipimap)->commit_sem);
 
 		/* update the inode map addressing structure to point to it */
 		if ((rc =
 		     xtInsert(tid, ipimap, 0, blkno, xlen, &xaddr, 0))) {
+			txEnd(tid);
+			up(&JFS_IP(ipimap)->commit_sem);
 			/* Free the blocks allocated for the iag since it was
 			 * not successfully added to the inode map
 			 */
@@ -2650,6 +2655,7 @@ diNewIAG(struct inomap * imap, int *iagnop, int agno, struct metapage ** mpp)
 		rc = txCommit(tid, 1, &iplist[0], COMMIT_FORCE);
 
 		txEnd(tid);
+		up(&JFS_IP(ipimap)->commit_sem);
 
 		duplicateIXtree(sb, blkno, xlen, &xaddr);