[Cluster-devel] [PATCH] gfs2: Remove sdp->sd_jheightsize

[Andreas Gruenbacher]

GFS2 keeps two arrarys in the superblock that define the maximum size of
an inode depending on the inode's height: sdp->sd_heightsize defines the
heights in units of sb->s_blocksize; sdp->sd_jheightsize defines them in
units of sb->s_blocksize - sizeof(struct gfs2_meta_header).  These
arrays are used to determine when additional layers of indirect blocks
are needed.  The second array is used for directories which have an
additional gfs2_meta_header at the beginning of each block.

Distinguishing between these two cases makes no sense: the height
required for representing N blocks will come out the same no matter if
the calculation is done in gross (sb->s_blocksize) or net
(sb->s_blocksize - sizeof(struct gfs2_meta_header)) units.

Stuffed directories don't have an additional gfs2_meta_header, but the
stuffed case is handled separately for both files and directories,
anyway.

Remove the unncessary sdp->sd_jheightsize array.

Signed-off-by: Andreas Gruenbacher <agruenba at redhat.com>
---
 fs/gfs2/bmap.c       | 14 +-------------
 fs/gfs2/incore.h     |  2 --
 fs/gfs2/ops_fstype.c | 19 -------------------
 3 files changed, 1 insertion(+), 34 deletions(-)

diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c
index 278ed0869c3c..0590e93494f7 100644
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -700,8 +700,6 @@ int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
 	struct gfs2_inode *ip = GFS2_I(inode);
 	struct gfs2_sbd *sdp = GFS2_SB(inode);
 	struct metapath mp = { .mp_aheight = 1, };
-	unsigned int factor = sdp->sd_sb.sb_bsize;
-	const u64 *arr = sdp->sd_heightsize;
 	__be64 *ptr;
 	sector_t lblock;
 	sector_t lend;
@@ -737,22 +735,12 @@ int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
 	iomap->flags = IOMAP_F_MERGED;
 	bmap_lock(ip, flags & IOMAP_WRITE);
 
-	/*
-	 * Directory data blocks have a struct gfs2_meta_header header, so the
-	 * remaining size is smaller than the filesystem block size.  Logical
-	 * block numbers for directories are in units of this remaining size!
-	 */
-	if (gfs2_is_dir(ip)) {
-		factor = sdp->sd_jbsize;
-		arr = sdp->sd_jheightsize;
-	}
-
 	ret = gfs2_meta_inode_buffer(ip, &mp.mp_bh[0]);
 	if (ret)
 		goto out_release;
 
 	height = ip->i_height;
-	while ((lblock + 1) * factor > arr[height])
+	while ((lblock + 1) * sdp->sd_sb.sb_bsize > sdp->sd_heightsize[height])
 		height++;
 	find_metapath(sdp, lblock, &mp, height);
 	if (height > ip->i_height || gfs2_is_stuffed(ip))
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 1b6b1e3f5caf..0bbbaa9b05cb 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -696,8 +696,6 @@ struct gfs2_sbd {
 	u32 sd_max_dirres;	/* Max blocks needed to add a directory entry */
 	u32 sd_max_height;	/* Max height of a file's metadata tree */
 	u64 sd_heightsize[GFS2_MAX_META_HEIGHT + 1];
-	u32 sd_max_jheight; /* Max height of journaled file's meta tree */
-	u64 sd_jheightsize[GFS2_MAX_META_HEIGHT + 1];
 	u32 sd_max_dents_per_leaf; /* Max number of dirents in a leaf block */
 
 	struct gfs2_args sd_args;	/* Mount arguments */
diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c
index 3ba3f167641c..c2469833b4fb 100644
--- a/fs/gfs2/ops_fstype.c
+++ b/fs/gfs2/ops_fstype.c
@@ -335,25 +335,6 @@ static int gfs2_read_sb(struct gfs2_sbd *sdp, int silent)
 	sdp->sd_heightsize[x] = ~0;
 	gfs2_assert(sdp, sdp->sd_max_height <= GFS2_MAX_META_HEIGHT);
 
-	sdp->sd_jheightsize[0] = sdp->sd_sb.sb_bsize -
-				 sizeof(struct gfs2_dinode);
-	sdp->sd_jheightsize[1] = sdp->sd_jbsize * sdp->sd_diptrs;
-	for (x = 2;; x++) {
-		u64 space, d;
-		u32 m;
-
-		space = sdp->sd_jheightsize[x - 1] * sdp->sd_inptrs;
-		d = space;
-		m = do_div(d, sdp->sd_inptrs);
-
-		if (d != sdp->sd_jheightsize[x - 1] || m)
-			break;
-		sdp->sd_jheightsize[x] = space;
-	}
-	sdp->sd_max_jheight = x;
-	sdp->sd_jheightsize[x] = ~0;
-	gfs2_assert(sdp, sdp->sd_max_jheight <= GFS2_MAX_META_HEIGHT);
-
 	sdp->sd_max_dents_per_leaf = (sdp->sd_sb.sb_bsize -
 				      sizeof(struct gfs2_leaf)) /
 				     GFS2_MIN_DIRENT_SIZE;
-- 
2.14.3