xfs: move firstblock and bmap freelist cursor into bmalloca structure

Rather than passing the firstblock and freelist structure around,
embed it into the bmalloca structure and remove it from the function
parameters.

This also enables the minleft parameter to be set only once in
xfs_bmapi_write(), and the freelist cursor directly queried in
xfs_bmapi_allocate to clear it when the lowspace algorithm is
activated.
    
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>


diff --git a/fs/xfs/xfs_bmap.c b/fs/xfs/xfs_bmap.c
index 68edf99..608a001 100644
--- a/fs/xfs/xfs_bmap.c
+++ b/fs/xfs/xfs_bmap.c
@@ -2006,9 +2006,9 @@
 		XFS_FSB_TO_AGBNO(mp, x) < mp->m_sb.sb_agblocks)
 
 	mp = ap->ip->i_mount;
-	nullfb = ap->firstblock == NULLFSBLOCK;
+	nullfb = *ap->firstblock == NULLFSBLOCK;
 	rt = XFS_IS_REALTIME_INODE(ap->ip) && ap->userdata;
-	fb_agno = nullfb ? NULLAGNUMBER : XFS_FSB_TO_AGNO(mp, ap->firstblock);
+	fb_agno = nullfb ? NULLAGNUMBER : XFS_FSB_TO_AGNO(mp, *ap->firstblock);
 	/*
 	 * If allocating at eof, and there's a previous real block,
 	 * try to use its last block as our starting point.
@@ -2380,8 +2380,8 @@
 		ASSERT(!error);
 		ASSERT(ap->alen);
 	}
-	nullfb = ap->firstblock == NULLFSBLOCK;
-	fb_agno = nullfb ? NULLAGNUMBER : XFS_FSB_TO_AGNO(mp, ap->firstblock);
+	nullfb = *ap->firstblock == NULLFSBLOCK;
+	fb_agno = nullfb ? NULLAGNUMBER : XFS_FSB_TO_AGNO(mp, *ap->firstblock);
 	if (nullfb) {
 		if (ap->userdata && xfs_inode_is_filestream(ap->ip)) {
 			ag = xfs_filestream_lookup_ag(ap->ip);
@@ -2391,7 +2391,7 @@
 			ap->rval = XFS_INO_TO_FSB(mp, ap->ip->i_ino);
 		}
 	} else
-		ap->rval = ap->firstblock;
+		ap->rval = *ap->firstblock;
 
 	xfs_bmap_adjacent(ap);
 
@@ -2402,7 +2402,7 @@
 	if (nullfb || XFS_FSB_TO_AGNO(mp, ap->rval) == fb_agno)
 		;
 	else
-		ap->rval = ap->firstblock;
+		ap->rval = *ap->firstblock;
 	/*
 	 * Normal allocation, done through xfs_alloc_vextent.
 	 */
@@ -2413,13 +2413,13 @@
 
 	/* Trim the allocation back to the maximum an AG can fit. */
 	args.maxlen = MIN(ap->alen, XFS_ALLOC_AG_MAX_USABLE(mp));
-	args.firstblock = ap->firstblock;
+	args.firstblock = *ap->firstblock;
 	blen = 0;
 	if (nullfb) {
 		error = xfs_bmap_btalloc_nullfb(ap, &args, &blen);
 		if (error)
 			return error;
-	} else if (ap->low) {
+	} else if (ap->flist->xbf_low) {
 		if (xfs_inode_is_filestream(ap->ip))
 			args.type = XFS_ALLOCTYPE_FIRST_AG;
 		else
@@ -2452,7 +2452,7 @@
 	 * is >= the stripe unit and the allocation offset is
 	 * at the end of file.
 	 */
-	if (!ap->low && ap->aeof) {
+	if (!ap->flist->xbf_low && ap->aeof) {
 		if (!ap->off) {
 			args.alignment = mp->m_dalign;
 			atype = args.type;
@@ -2540,12 +2540,25 @@
 		args.minleft = 0;
 		if ((error = xfs_alloc_vextent(&args)))
 			return error;
-		ap->low = 1;
+		ap->flist->xbf_low = 1;
 	}
 	if (args.fsbno != NULLFSBLOCK) {
-		ap->firstblock = ap->rval = args.fsbno;
+		/*
+		 * check the allocation happened at the same or higher AG than
+		 * the first block that was allocated.
+		 */
+		ASSERT(*ap->firstblock == NULLFSBLOCK ||
+		       XFS_FSB_TO_AGNO(mp, *ap->firstblock) ==
+		       XFS_FSB_TO_AGNO(mp, args.fsbno) ||
+		       (ap->flist->xbf_low &&
+			XFS_FSB_TO_AGNO(mp, *ap->firstblock) <
+			XFS_FSB_TO_AGNO(mp, args.fsbno)));
+
+		ap->rval = args.fsbno;
+		if (*ap->firstblock == NULLFSBLOCK)
+			*ap->firstblock = args.fsbno;
 		ASSERT(nullfb || fb_agno == args.agno ||
-		       (ap->low && fb_agno < args.agno));
+		       (ap->flist->xbf_low && fb_agno < args.agno));
 		ap->alen = args.len;
 		ap->ip->i_d.di_nblocks += args.len;
 		xfs_trans_log_inode(ap->tp, ap->ip, XFS_ILOG_CORE);
@@ -4596,8 +4609,6 @@
 	struct xfs_bmalloca	*bma,
 	xfs_extnum_t		*lastx,
 	struct xfs_btree_cur	**cur,
-	xfs_fsblock_t		*firstblock,
-	struct xfs_bmap_free	*flist,
 	int			flags,
 	int			*nallocs,
 	int			*logflags)
@@ -4647,9 +4658,7 @@
 	 */
 	bma->alen = alen;
 	bma->off = aoff;
-	bma->firstblock = *firstblock;
 	bma->minlen = (flags & XFS_BMAPI_CONTIG) ? alen : 1;
-	bma->low = flist->xbf_low;
 	bma->aeof = 0;
 
 	/*
@@ -4671,24 +4680,18 @@
 	 * Copy out result fields.
 	 */
 	abno = bma->rval;
-	flist->xbf_low = bma->low;
 	alen = bma->alen;
 	aoff = bma->off;
-	ASSERT(*firstblock == NULLFSBLOCK ||
-	       XFS_FSB_TO_AGNO(mp, *firstblock) ==
-	       XFS_FSB_TO_AGNO(mp, bma->firstblock) ||
-	       (flist->xbf_low &&
-		XFS_FSB_TO_AGNO(mp, *firstblock) <
-			XFS_FSB_TO_AGNO(mp, bma->firstblock)));
-	*firstblock = bma->firstblock;
+	if (bma->flist->xbf_low)
+		bma->minleft = 0;
 	if (*cur)
-		(*cur)->bc_private.b.firstblock = *firstblock;
+		(*cur)->bc_private.b.firstblock = *bma->firstblock;
 	if (abno == NULLFSBLOCK)
 		return 0;
 	if ((ifp->if_flags & XFS_IFBROOT) && !*cur) {
 		(*cur) = xfs_bmbt_init_cursor(mp, bma->tp, bma->ip, whichfork);
-		(*cur)->bc_private.b.firstblock = *firstblock;
-		(*cur)->bc_private.b.flist = flist;
+		(*cur)->bc_private.b.firstblock = *bma->firstblock;
+		(*cur)->bc_private.b.flist = bma->flist;
 	}
 	/*
 	 * Bump the number of extents we've allocated
@@ -4715,11 +4718,12 @@
 
 	if (bma->wasdel) {
 		error = xfs_bmap_add_extent_delay_real(bma->tp, bma->ip, lastx,
-				cur, &bma->got, firstblock, flist, logflags);
+				cur, &bma->got, bma->firstblock, bma->flist,
+				logflags);
 	} else {
 		error = xfs_bmap_add_extent_hole_real(bma->tp, bma->ip, lastx,
-				cur, &bma->got, firstblock, flist, logflags,
-				whichfork);
+				cur, &bma->got, bma->firstblock, bma->flist,
+				logflags, whichfork);
 	}
 
 	if (error)
@@ -4746,8 +4750,6 @@
 	xfs_filblks_t		len,
 	xfs_extnum_t		*lastx,
 	struct xfs_btree_cur	**cur,
-	xfs_fsblock_t		*firstblock,
-	struct xfs_bmap_free	*flist,
 	int			flags,
 	int			*logflags)
 {
@@ -4776,14 +4778,14 @@
 	if ((ifp->if_flags & XFS_IFBROOT) && !*cur) {
 		*cur = xfs_bmbt_init_cursor(bma->ip->i_mount, bma->tp,
 					bma->ip, whichfork);
-		(*cur)->bc_private.b.firstblock = *firstblock;
-		(*cur)->bc_private.b.flist = flist;
+		(*cur)->bc_private.b.firstblock = *bma->firstblock;
+		(*cur)->bc_private.b.flist = bma->flist;
 	}
 	mval->br_state = (mval->br_state == XFS_EXT_UNWRITTEN)
 				? XFS_EXT_NORM : XFS_EXT_UNWRITTEN;
 
 	error = xfs_bmap_add_extent_unwritten_real(bma->tp, bma->ip, lastx,
-			cur, mval, firstblock, flist, logflags);
+			cur, mval, bma->firstblock, bma->flist, logflags);
 	if (error)
 		return error;
 
@@ -4838,7 +4840,6 @@
 	int			error;		/* error return */
 	xfs_extnum_t		lastx;		/* last useful extent number */
 	int			logflags;	/* flags for transaction logging */
-	xfs_extlen_t		minleft;	/* min blocks left after allocation */
 	int			n;		/* current extent index */
 	int			nallocs;	/* number of extents alloc'd */
 	xfs_fileoff_t		obno;		/* old block number (offset) */
@@ -4900,11 +4901,11 @@
 
 	if (*firstblock == NULLFSBLOCK) {
 		if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_BTREE)
-			minleft = be16_to_cpu(ifp->if_broot->bb_level) + 1;
+			bma.minleft = be16_to_cpu(ifp->if_broot->bb_level) + 1;
 		else
-			minleft = 1;
+			bma.minleft = 1;
 	} else {
-		minleft = 0;
+		bma.minleft = 0;
 	}
 
 	if (!(ifp->if_flags & XFS_IFEXTENTS)) {
@@ -4923,6 +4924,8 @@
 	bma.ip = ip;
 	bma.total = total;
 	bma.userdata = 0;
+	bma.flist = flist;
+	bma.firstblock = firstblock;
 
 	while (bno < end && n < *nmap) {
 		inhole = eof || bma.got.br_startoff > bno;
@@ -4938,16 +4941,12 @@
 			bma.wasdel = wasdelay;
 			bma.alen = len;
 			bma.off = bno;
-			bma.minleft = minleft;
 
-			error = xfs_bmapi_allocate(&bma, &lastx, &cur,
-					firstblock, flist, flags, &nallocs,
-					&tmp_logflags);
+			error = xfs_bmapi_allocate(&bma, &lastx, &cur, flags,
+					&nallocs, &tmp_logflags);
 			logflags |= tmp_logflags;
 			if (error)
 				goto error0;
-			if (flist && flist->xbf_low)
-				minleft = 0;
 			if (bma.rval == NULLFSBLOCK)
 				break;
 		}
@@ -4958,8 +4957,7 @@
 
 		/* Execute unwritten extent conversion if necessary */
 		error = xfs_bmapi_convert_unwritten(&bma, mval, len, &lastx,
-						    &cur, firstblock, flist,
-						    flags, &tmp_logflags);
+						    &cur, flags, &tmp_logflags);
 		logflags |= tmp_logflags;
 		if (error == EAGAIN)
 			continue;