Sprinkle DOINGASYNC() checks so as to do delayed writes for async

mounts in almost all cases instead of in most cases.  Don't override
DOINGASYNC() by any condition except IO_SYNC.

Fix previous sprinking of DOINGASYNC() checks.  Don't override IO_SYNC
by DOINGASYNC().  In ffs_write() and ffs_extwrite(), there were
intentional overrides that just broke O_SYNC of data.  In
ffs_truncate(), there are 5 calls to ffs_update(), 4 with
apparently-unintentional overrides and 1 without; this had no effect
due to the main async mount hack descibed below.

Fix 1 place in ffs_truncate() where the caller's IO_ASYNC was overridden
for the soft updates case too (to do a delayed write instead of a sync
write).  This is supposed to be the only change that affects anything
except async mounts.

In ffs_update(), remove the 19 year old efficiency hack of ignoring
the waitfor flag for async mounts, so that fsync() almost works for
async mounts.  All callers are supposed to be fixed to not ask for a
sync update unless they are for fsync() or [I]O_SYNC operations.
fsync() now almost works for async mounts.  It used to sync the data
but not the most important metdata (the inode).  It still doesn't sync
associated directories.

This gave 10-20% fewer writes for my makeworld benchmark with async
mounted tmp and obj directories from an already small number.

Style fixes:
- in ffs_balloc.c, remove rotted quadruplicated comments about the
  simplest part of the DOING*() decisions and rearrange the nearly-
  quadruplicated code to be more nearly so.
- in ufs_vnops.c, use a consistent style with less negative logic and
  no manual "optimization" of || to | in DOING*() expressions.

Reviewed by:	kib (previous version)

5 files changed, 44 insertions, 45 deletions

diff --git a/sys/ufs/ffs/ffs_balloc.c b/sys/ufs/ffs/ffs_balloc.c
index 04e0ae93b232..676dcb4e4d4c 100644
--- a/sys/ufs/ffs/ffs_balloc.c
+++ b/sys/ufs/ffs/ffs_balloc.c
@@ -154,6 +154,8 @@ ffs_balloc_ufs1(struct vnode *vp, off_t startoffset, int size,
 			ip->i_flag |= IN_CHANGE | IN_UPDATE;
 			if (flags & IO_SYNC)
 				bwrite(bp);
+			else if (DOINGASYNC(vp))
+				bdwrite(bp);
 			else
 				bawrite(bp);
 		}
@@ -266,14 +268,12 @@ ffs_balloc_ufs1(struct vnode *vp, off_t startoffset, int size,
 			softdep_setup_allocdirect(ip, NDADDR + indirs[0].in_off,
 			    newb, 0, fs->fs_bsize, 0, bp);
 			bdwrite(bp);
+		} else if ((flags & IO_SYNC) == 0 && DOINGASYNC(vp)) {
+			if (bp->b_bufsize == fs->fs_bsize)
+				bp->b_flags |= B_CLUSTEROK;
+			bdwrite(bp);
 		} else {
-			/*
-			 * Write synchronously so that indirect blocks
-			 * never point at garbage.
-			 */
-			if (DOINGASYNC(vp))
-				bdwrite(bp);
-			else if ((error = bwrite(bp)) != 0)
+			if ((error = bwrite(bp)) != 0)
 				goto fail;
 		}
 		allocib = &dp->di_ib[indirs[0].in_off];
@@ -338,11 +338,11 @@ retry:
 			softdep_setup_allocindir_meta(nbp, ip, bp,
 			    indirs[i - 1].in_off, nb);
 			bdwrite(nbp);
+		} else if ((flags & IO_SYNC) == 0 && DOINGASYNC(vp)) {
+			if (nbp->b_bufsize == fs->fs_bsize)
+				nbp->b_flags |= B_CLUSTEROK;
+			bdwrite(nbp);
 		} else {
-			/*
-			 * Write synchronously so that indirect blocks
-			 * never point at garbage.
-			 */
 			if ((error = bwrite(nbp)) != 0) {
 				brelse(bp);
 				goto fail;
@@ -854,14 +854,12 @@ ffs_balloc_ufs2(struct vnode *vp, off_t startoffset, int size,
 			softdep_setup_allocdirect(ip, NDADDR + indirs[0].in_off,
 			    newb, 0, fs->fs_bsize, 0, bp);
 			bdwrite(bp);
+		} else if ((flags & IO_SYNC) == 0 && DOINGASYNC(vp)) {
+			if (bp->b_bufsize == fs->fs_bsize)
+				bp->b_flags |= B_CLUSTEROK;
+			bdwrite(bp);
 		} else {
-			/*
-			 * Write synchronously so that indirect blocks
-			 * never point at garbage.
-			 */
-			if (DOINGASYNC(vp))
-				bdwrite(bp);
-			else if ((error = bwrite(bp)) != 0)
+			if ((error = bwrite(bp)) != 0)
 				goto fail;
 		}
 		allocib = &dp->di_ib[indirs[0].in_off];
@@ -927,11 +925,11 @@ retry:
 			softdep_setup_allocindir_meta(nbp, ip, bp,
 			    indirs[i - 1].in_off, nb);
 			bdwrite(nbp);
+		} else if ((flags & IO_SYNC) == 0 && DOINGASYNC(vp)) {
+			if (nbp->b_bufsize == fs->fs_bsize)
+				nbp->b_flags |= B_CLUSTEROK;
+			bdwrite(nbp);
 		} else {
-			/*
-			 * Write synchronously so that indirect blocks
-			 * never point at garbage.
-			 */
 			if ((error = bwrite(nbp)) != 0) {
 				brelse(bp);
 				goto fail;
diff --git a/sys/ufs/ffs/ffs_inode.c b/sys/ufs/ffs/ffs_inode.c
index 50b456bd7878..4bd38d58692f 100644
--- a/sys/ufs/ffs/ffs_inode.c
+++ b/sys/ufs/ffs/ffs_inode.c
@@ -154,7 +154,7 @@ loop:
 		/* XXX: FIX? The entropy here is desirable, but the harvesting may be expensive */
 		random_harvest_queue(&(ip->i_din2), sizeof(ip->i_din2), 1, RANDOM_FS_ATIME);
 	}
-	if (waitfor && !DOINGASYNC(vp))
+	if (waitfor)
 		error = bwrite(bp);
 	else if (vm_page_count_severe() || buf_dirty_count_severe()) {
 		bawrite(bp);
@@ -193,7 +193,7 @@ ffs_truncate(vp, length, flags, cred)
 	int softdeptrunc, journaltrunc;
 	int needextclean, extblocks;
 	int offset, size, level, nblocks;
-	int i, error, allerror, indiroff;
+	int i, error, allerror, indiroff, waitforupdate;
 	off_t osize;
 
 	ip = VTOI(vp);
@@ -221,6 +221,7 @@ ffs_truncate(vp, length, flags, cred)
 		flags |= IO_NORMAL;
 	if (!DOINGSOFTDEP(vp) && !DOINGASYNC(vp))
 		flags |= IO_SYNC;
+	waitforupdate = (flags & IO_SYNC) != 0 || !DOINGASYNC(vp);
 	/*
 	 * If we are truncating the extended-attributes, and cannot
 	 * do it with soft updates, then do it slowly here. If we are
@@ -264,7 +265,7 @@ ffs_truncate(vp, length, flags, cred)
 				ip->i_din2->di_extb[i] = 0;
 			}
 			ip->i_flag |= IN_CHANGE;
-			if ((error = ffs_update(vp, !DOINGASYNC(vp))))
+			if ((error = ffs_update(vp, waitforupdate)))
 				return (error);
 			for (i = 0; i < NXADDR; i++) {
 				if (oldblks[i] == 0)
@@ -290,7 +291,7 @@ ffs_truncate(vp, length, flags, cred)
 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
 		if (needextclean)
 			goto extclean;
-		return (ffs_update(vp, !DOINGASYNC(vp)));
+		return (ffs_update(vp, waitforupdate));
 	}
 	if (ip->i_size == length) {
 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
@@ -328,7 +329,7 @@ ffs_truncate(vp, length, flags, cred)
 		else
 			bawrite(bp);
 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
-		return (ffs_update(vp, !DOINGASYNC(vp)));
+		return (ffs_update(vp, waitforupdate));
 	}
 	/*
 	 * Lookup block number for a given offset. Zero length files
@@ -357,10 +358,10 @@ ffs_truncate(vp, length, flags, cred)
 		 */
 		if (blkno != 0)
 			brelse(bp);
-		else if (DOINGSOFTDEP(vp) || DOINGASYNC(vp))
-			bdwrite(bp);
-		else
+		else if (flags & IO_SYNC)
 			bwrite(bp);
+		else
+			bdwrite(bp);
 	}
 	/*
 	 * If the block number at the new end of the file is zero,
@@ -478,7 +479,7 @@ ffs_truncate(vp, length, flags, cred)
 			DIP_SET(ip, i_db[i], 0);
 	}
 	ip->i_flag |= IN_CHANGE | IN_UPDATE;
-	allerror = ffs_update(vp, !DOINGASYNC(vp));
+	allerror = ffs_update(vp, waitforupdate);
 	
 	/*
 	 * Having written the new inode to disk, save its new configuration
@@ -610,7 +611,7 @@ extclean:
 		softdep_journal_freeblocks(ip, cred, length, IO_EXT);
 	else
 		softdep_setup_freeblocks(ip, length, IO_EXT);
-	return (ffs_update(vp, (flags & IO_SYNC) != 0 || !DOINGASYNC(vp)));
+	return (ffs_update(vp, waitforupdate));
 }
 
 /*
diff --git a/sys/ufs/ffs/ffs_vnops.c b/sys/ufs/ffs/ffs_vnops.c
index 27654804046d..0ed7c5923986 100644
--- a/sys/ufs/ffs/ffs_vnops.c
+++ b/sys/ufs/ffs/ffs_vnops.c
@@ -757,7 +757,7 @@ ffs_write(ap)
 		flags = BA_SEQMAX << BA_SEQSHIFT;
 	else
 		flags = seqcount << BA_SEQSHIFT;
-	if ((ioflag & IO_SYNC) && !DOINGASYNC(vp))
+	if (ioflag & IO_SYNC)
 		flags |= IO_SYNC;
 	flags |= BA_UNMAPPED;
 
@@ -1077,7 +1077,7 @@ ffs_extwrite(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *ucred)
 	resid = uio->uio_resid;
 	osize = dp->di_extsize;
 	flags = IO_EXT;
-	if ((ioflag & IO_SYNC) && !DOINGASYNC(vp))
+	if (ioflag & IO_SYNC)
 		flags |= IO_SYNC;
 
 	for (error = 0; uio->uio_resid > 0;) {
diff --git a/sys/ufs/ufs/ufs_lookup.c b/sys/ufs/ufs/ufs_lookup.c
index c3e3de9e8786..343162434eba 100644
--- a/sys/ufs/ufs/ufs_lookup.c
+++ b/sys/ufs/ufs/ufs_lookup.c
@@ -1237,7 +1237,7 @@ out:
 	} else {
 		if (flags & DOWHITEOUT)
 			error = bwrite(bp);
-		else if (DOINGASYNC(dvp) && dp->i_count != 0)
+		else if (DOINGASYNC(dvp))
 			bdwrite(bp);
 		else
 			error = bwrite(bp);
diff --git a/sys/ufs/ufs/ufs_vnops.c b/sys/ufs/ufs/ufs_vnops.c
index 07e59aa1ce16..46e5b24a36f0 100644
--- a/sys/ufs/ufs/ufs_vnops.c
+++ b/sys/ufs/ufs/ufs_vnops.c
@@ -991,7 +991,7 @@ ufs_link(ap)
 	ip->i_flag |= IN_CHANGE;
 	if (DOINGSOFTDEP(vp))
 		softdep_setup_link(VTOI(tdvp), ip);
-	error = UFS_UPDATE(vp, !(DOINGSOFTDEP(vp) | DOINGASYNC(vp)));
+	error = UFS_UPDATE(vp, !DOINGSOFTDEP(vp) && !DOINGASYNC(vp));
 	if (!error) {
 		ufs_makedirentry(ip, cnp, &newdir);
 		error = ufs_direnter(tdvp, vp, &newdir, cnp, NULL, 0);
@@ -1335,7 +1335,7 @@ relock:
 	fip->i_flag |= IN_CHANGE;
 	if (DOINGSOFTDEP(fvp))
 		softdep_setup_link(tdp, fip);
-	error = UFS_UPDATE(fvp, !(DOINGSOFTDEP(fvp) | DOINGASYNC(fvp)));
+	error = UFS_UPDATE(fvp, !DOINGSOFTDEP(fvp) && !DOINGASYNC(fvp));
 	if (error)
 		goto bad;
 
@@ -1488,8 +1488,8 @@ relock:
 			tdp->i_flag |= IN_CHANGE;
 			if (DOINGSOFTDEP(tdvp))
 				softdep_setup_dotdot_link(tdp, fip);
-			error = UFS_UPDATE(tdvp, !(DOINGSOFTDEP(tdvp) |
-						   DOINGASYNC(tdvp)));
+			error = UFS_UPDATE(tdvp, !DOINGSOFTDEP(tdvp) &&
+			    !DOINGASYNC(tdvp));
 			/* Don't go to bad here as the new link exists. */
 			if (error)
 				goto unlockout;
@@ -1529,8 +1529,8 @@ unlockout:
 	 * are no longer needed.
 	 */
 	if (error == 0 && endoff != 0) {
-		error = UFS_TRUNCATE(tdvp, endoff, IO_NORMAL | IO_SYNC,
-		    tcnp->cn_cred);
+		error = UFS_TRUNCATE(tdvp, endoff, IO_NORMAL |
+		    (DOINGASYNC(tdvp) ? 0 : IO_SYNC), tcnp->cn_cred);
 		if (error != 0)
 			vn_printf(tdvp, "ufs_rename: failed to truncate "
 			    "err %d", error);
@@ -1888,7 +1888,7 @@ ufs_mkdir(ap)
 	dp->i_flag |= IN_CHANGE;
 	if (DOINGSOFTDEP(dvp))
 		softdep_setup_mkdir(dp, ip);
-	error = UFS_UPDATE(dvp, !(DOINGSOFTDEP(dvp) | DOINGASYNC(dvp)));
+	error = UFS_UPDATE(dvp, !DOINGSOFTDEP(dvp) && !DOINGASYNC(dvp));
 	if (error)
 		goto bad;
 #ifdef MAC
@@ -1945,8 +1945,8 @@ ufs_mkdir(ap)
 			blkoff += DIRBLKSIZ;
 		}
 	}
-	if ((error = UFS_UPDATE(tvp, !(DOINGSOFTDEP(tvp) |
-				       DOINGASYNC(tvp)))) != 0) {
+	if ((error = UFS_UPDATE(tvp, !DOINGSOFTDEP(tvp) &&
+	    !DOINGASYNC(tvp))) != 0) {
 		(void)bwrite(bp);
 		goto bad;
 	}
@@ -2680,7 +2680,7 @@ ufs_makeinode(mode, dvp, vpp, cnp)
 	/*
 	 * Make sure inode goes to disk before directory entry.
 	 */
-	error = UFS_UPDATE(tvp, !(DOINGSOFTDEP(tvp) | DOINGASYNC(tvp)));
+	error = UFS_UPDATE(tvp, !DOINGSOFTDEP(tvp) && !DOINGASYNC(tvp));
 	if (error)
 		goto bad;
 #ifdef MAC