svn commit: r248165 - user/attilio/vmobj-readlock/sys/kern

[Attilio Rao]

Author: attilio
Date: Mon Mar 11 14:50:45 2013
New Revision: 248165
URL: http://svnweb.freebsd.org/changeset/base/248165

Log:
  Use vm_object read locking for brelse() and inmem().
  
  Sponsored by:	Isilon storage division

Modified:
  user/attilio/vmobj-readlock/sys/kern/vfs_bio.c

Modified: user/attilio/vmobj-readlock/sys/kern/vfs_bio.c
==============================================================================
--- user/attilio/vmobj-readlock/sys/kern/vfs_bio.c	Mon Mar 11 14:47:08 2013	(r248164)
+++ user/attilio/vmobj-readlock/sys/kern/vfs_bio.c	Mon Mar 11 14:50:45 2013	(r248165)
@@ -1389,7 +1389,7 @@ brelse(struct buf *bp)
 		 */
 		resid = bp->b_bufsize;
 		foff = bp->b_offset;
-		VM_OBJECT_WLOCK(obj);
+		VM_OBJECT_RLOCK(obj);
 		for (i = 0; i < bp->b_npages; i++) {
 			int had_bogus = 0;
 
@@ -1437,7 +1437,7 @@ brelse(struct buf *bp)
 			resid -= PAGE_SIZE - (foff & PAGE_MASK);
 			foff = (foff + PAGE_SIZE) & ~(off_t)PAGE_MASK;
 		}
-		VM_OBJECT_WUNLOCK(obj);
+		VM_OBJECT_RUNLOCK(obj);
 		if (bp->b_flags & (B_INVAL | B_RELBUF))
 			vfs_vmio_release(bp);
 
@@ -2468,7 +2468,7 @@ inmem(struct vnode * vp, daddr_t blkno)
 		size = vp->v_mount->mnt_stat.f_iosize;
 	off = (vm_ooffset_t)blkno * (vm_ooffset_t)vp->v_mount->mnt_stat.f_iosize;
 
-	VM_OBJECT_WLOCK(obj);
+	VM_OBJECT_RLOCK(obj);
 	for (toff = 0; toff < vp->v_mount->mnt_stat.f_iosize; toff += tinc) {
 		m = vm_page_lookup(obj, OFF_TO_IDX(off + toff));
 		if (!m)
@@ -2480,7 +2480,7 @@ inmem(struct vnode * vp, daddr_t blkno)
 		    (vm_offset_t) ((toff + off) & PAGE_MASK), tinc) == 0)
 			goto notinmem;
 	}
-	VM_OBJECT_WUNLOCK(obj);
+	VM_OBJECT_RUNLOCK(obj);
 	return 1;
 
 notinmem: