svn commit: r248500 - in head/sys: fs/nfsclient nfsclient

[Ed Maste]

Author: emaste
Date: Tue Mar 19 13:06:11 2013
New Revision: 248500
URL: http://svnweb.freebsd.org/changeset/base/248500

Log:
  Fix remainder calculation when biosize is not a power of 2
  
  In common configurations biosize is a power of two, but is not required to
  be so.  Thanks to markj@ for spotting an additional case beyond my original
  patch.
  
  Reviewed by: rmacklem@

Modified:
  head/sys/fs/nfsclient/nfs_clbio.c
  head/sys/nfsclient/nfs_bio.c

Modified: head/sys/fs/nfsclient/nfs_clbio.c
==============================================================================
--- head/sys/fs/nfsclient/nfs_clbio.c	Tue Mar 19 12:52:13 2013	(r248499)
+++ head/sys/fs/nfsclient/nfs_clbio.c	Tue Mar 19 13:06:11 2013	(r248500)
@@ -484,7 +484,7 @@ ncl_bioread(struct vnode *vp, struct uio
 	    case VREG:
 		NFSINCRGLOBAL(newnfsstats.biocache_reads);
 		lbn = uio->uio_offset / biosize;
-		on = uio->uio_offset & (biosize - 1);
+		on = uio->uio_offset - (lbn * biosize);
 
 		/*
 		 * Start the read ahead(s), as required.
@@ -1029,7 +1029,7 @@ flush_and_restart:
 	do {
 		NFSINCRGLOBAL(newnfsstats.biocache_writes);
 		lbn = uio->uio_offset / biosize;
-		on = uio->uio_offset & (biosize-1);
+		on = uio->uio_offset - (lbn * biosize);
 		n = MIN((unsigned)(biosize - on), uio->uio_resid);
 again:
 		/*
@@ -1847,7 +1847,7 @@ ncl_meta_setsize(struct vnode *vp, struc
 		 */
 		error = vtruncbuf(vp, cred, nsize, biosize);
 		lbn = nsize / biosize;
-		bufsize = nsize & (biosize - 1);
+		bufsize = nsize - (lbn * biosize);
 		bp = nfs_getcacheblk(vp, lbn, bufsize, td);
  		if (!bp)
  			return EINTR;

Modified: head/sys/nfsclient/nfs_bio.c
==============================================================================
--- head/sys/nfsclient/nfs_bio.c	Tue Mar 19 12:52:13 2013	(r248499)
+++ head/sys/nfsclient/nfs_bio.c	Tue Mar 19 13:06:11 2013	(r248500)
@@ -475,7 +475,7 @@ nfs_bioread(struct vnode *vp, struct uio
 	    case VREG:
 		nfsstats.biocache_reads++;
 		lbn = uio->uio_offset / biosize;
-		on = uio->uio_offset & (biosize - 1);
+		on = uio->uio_offset - (lbn * biosize);
 
 		/*
 		 * Start the read ahead(s), as required.
@@ -1011,7 +1011,7 @@ flush_and_restart:
 	do {
 		nfsstats.biocache_writes++;
 		lbn = uio->uio_offset / biosize;
-		on = uio->uio_offset & (biosize-1);
+		on = uio->uio_offset - (lbn * biosize);
 		n = MIN((unsigned)(biosize - on), uio->uio_resid);
 again:
 		/*
@@ -1781,7 +1781,7 @@ nfs_meta_setsize(struct vnode *vp, struc
 		 */
 		error = vtruncbuf(vp, cred, nsize, biosize);
 		lbn = nsize / biosize;
-		bufsize = nsize & (biosize - 1);
+		bufsize = nsize - (lbn * biosize);
 		bp = nfs_getcacheblk(vp, lbn, bufsize, td);
  		if (!bp)
  			return EINTR;