jfs: remove xtLookupList()

xtLookupList() was a more generalized version of xtLookup() with a
nastier interface.  Its only caller, extHint(), is actually better
suited to using xtLookup() than xtLookupList().  This also lets us
remove the definition of lxd_t, an obnoxious packed structure that was
only used in-memory.

Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>

fs/jfs/jfs_extent.c

@@ -362,11 +362,12 @@ exit:
 int extHint(struct inode *ip, s64 offset, xad_t * xp)
 {
 	struct super_block *sb = ip->i_sb;
-	struct xadlist xadl;
-	struct lxdlist lxdl;
-	lxd_t lxd;
+	int nbperpage = JFS_SBI(sb)->nbperpage;
 	s64 prev;
-	int rc, nbperpage = JFS_SBI(sb)->nbperpage;
+	int rc = 0;
+	s64 xaddr;
+	int xlen;
+	int xflag;
 
 	/* init the hint as "no hint provided" */
 	XADaddress(xp, 0);
@@ -376,46 +377,30 @@ int extHint(struct inode *ip, s64 offset, xad_t * xp)
 	 */
 	prev = ((offset & ~POFFSET) >> JFS_SBI(sb)->l2bsize) - nbperpage;
 
-	/* if the offsets in the first page of the file,
-	 * no hint provided.
+	/* if the offset is in the first page of the file, no hint provided.
 	 */
 	if (prev < 0)
-		return (0);
-
-	/* prepare to lookup the previous page's extent info */
-	lxdl.maxnlxd = 1;
-	lxdl.nlxd = 1;
-	lxdl.lxd = &lxd;
-	LXDoffset(&lxd, prev)
-	LXDlength(&lxd, nbperpage);
-
-	xadl.maxnxad = 1;
-	xadl.nxad = 0;
-	xadl.xad = xp;
-
-	/* perform the lookup */
-	if ((rc = xtLookupList(ip, &lxdl, &xadl, 0)))
-		return (rc);
-
-	/* check if no extent exists for the previous page.
-	 * this is possible for sparse files.
-	 */
-	if (xadl.nxad == 0) {
-//		assert(ISSPARSE(ip));
-		return (0);
-	}
+		goto out;
 
-	/* only preserve the abnr flag within the xad flags
-	 * of the returned hint.
-	 */
-	xp->flag &= XAD_NOTRECORDED;
+	rc = xtLookup(ip, prev, nbperpage, &xflag, &xaddr, &xlen, 0);
 
-	if(xadl.nxad != 1 || lengthXAD(xp) != nbperpage) {
-		jfs_error(ip->i_sb, "extHint: corrupt xtree");
-		return -EIO;
-	}
+	if ((rc == 0) && xlen) {
+		if (xlen != nbperpage) {
+			jfs_error(ip->i_sb, "extHint: corrupt xtree");
+			rc = -EIO;
+		}
+		XADaddress(xp, xaddr);
+		XADlength(xp, xlen);
+		/*
+		 * only preserve the abnr flag within the xad flags
+		 * of the returned hint.
+		 */
+		xp->flag  = xflag & XAD_NOTRECORDED;
+	} else
+		rc = 0;
 
-	return (0);
+out:
+	return (rc);
 }
 
 

fs/jfs/jfs_types.h

@@ -57,35 +57,6 @@ struct timestruc_t {
 #define	HIGHORDER	0x80000000u	/* high order bit on	*/
 #define	ONES		0xffffffffu	/* all bit on		*/
 
-/*
- *	logical xd (lxd)
- */
-typedef struct {
-	unsigned len:24;
-	unsigned off1:8;
-	u32 off2;
-} lxd_t;
-
-/* lxd_t field construction */
-#define	LXDlength(lxd, length32)	( (lxd)->len = length32 )
-#define	LXDoffset(lxd, offset64)\
-{\
-	(lxd)->off1 = ((s64)offset64) >> 32;\
-	(lxd)->off2 = (offset64) & 0xffffffff;\
-}
-
-/* lxd_t field extraction */
-#define	lengthLXD(lxd)	( (lxd)->len )
-#define	offsetLXD(lxd)\
-	( ((s64)((lxd)->off1)) << 32 | (lxd)->off2 )
-
-/* lxd list */
-struct lxdlist {
-	s16 maxnlxd;
-	s16 nlxd;
-	lxd_t *lxd;
-};
-
 /*
  *	physical xd (pxd)
  */

fs/jfs/jfs_xtree.c

@@ -164,11 +164,8 @@ int xtLookup(struct inode *ip, s64 lstart,
 		/* is lookup offset beyond eof ? */
 		size = ((u64) ip->i_size + (JFS_SBI(ip->i_sb)->bsize - 1)) >>
 		    JFS_SBI(ip->i_sb)->l2bsize;
-		if (lstart >= size) {
-			jfs_err("xtLookup: lstart (0x%lx) >= size (0x%lx)",
-				(ulong) lstart, (ulong) size);
+		if (lstart >= size)
 			return 0;
-		}
 	}
 
 	/*
@@ -220,264 +217,6 @@ int xtLookup(struct inode *ip, s64 lstart,
 	return rc;
 }
 
-
-/*
- *	xtLookupList()
- *
- * function: map a single logical extent into a list of physical extent;
- *
- * parameter:
- *	struct inode	*ip,
- *	struct lxdlist	*lxdlist,	lxd list (in)
- *	struct xadlist	*xadlist,	xad list (in/out)
- *	int		flag)
- *
- * coverage of lxd by xad under assumption of
- * . lxd's are ordered and disjoint.
- * . xad's are ordered and disjoint.
- *
- * return:
- *	0:	success
- *
- * note: a page being written (even a single byte) is backed fully,
- *	except the last page which is only backed with blocks
- *	required to cover the last byte;
- *	the extent backing a page is fully contained within an xad;
- */
-int xtLookupList(struct inode *ip, struct lxdlist * lxdlist,
-		 struct xadlist * xadlist, int flag)
-{
-	int rc = 0;
-	struct btstack btstack;
-	int cmp;
-	s64 bn;
-	struct metapage *mp;
-	xtpage_t *p;
-	int index;
-	lxd_t *lxd;
-	xad_t *xad, *pxd;
-	s64 size, lstart, lend, xstart, xend, pstart;
-	s64 llen, xlen, plen;
-	s64 xaddr, paddr;
-	int nlxd, npxd, maxnpxd;
-
-	npxd = xadlist->nxad = 0;
-	maxnpxd = xadlist->maxnxad;
-	pxd = xadlist->xad;
-
-	nlxd = lxdlist->nlxd;
-	lxd = lxdlist->lxd;
-
-	lstart = offsetLXD(lxd);
-	llen = lengthLXD(lxd);
-	lend = lstart + llen;
-
-	size = (ip->i_size + (JFS_SBI(ip->i_sb)->bsize - 1)) >>
-	    JFS_SBI(ip->i_sb)->l2bsize;
-
-	/*
-	 * search for the xad entry covering the logical extent
-	 */
-      search:
-	if (lstart >= size)
-		return 0;
-
-	if ((rc = xtSearch(ip, lstart, NULL, &cmp, &btstack, 0)))
-		return rc;
-
-	/*
-	 *	compute the physical extent covering logical extent
-	 *
-	 * N.B. search may have failed (e.g., hole in sparse file),
-	 * and returned the index of the next entry.
-	 */
-//map:
-	/* retrieve search result */
-	XT_GETSEARCH(ip, btstack.top, bn, mp, p, index);
-
-	/* is xad on the next sibling page ? */
-	if (index == le16_to_cpu(p->header.nextindex)) {
-		if (p->header.flag & BT_ROOT)
-			goto mapend;
-
-		if ((bn = le64_to_cpu(p->header.next)) == 0)
-			goto mapend;
-
-		XT_PUTPAGE(mp);
-
-		/* get next sibling page */
-		XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
-		if (rc)
-			return rc;
-
-		index = XTENTRYSTART;
-	}
-
-	xad = &p->xad[index];
-
-	/*
-	 * is lxd covered by xad ?
-	 */
-      compare:
-	xstart = offsetXAD(xad);
-	xlen = lengthXAD(xad);
-	xend = xstart + xlen;
-	xaddr = addressXAD(xad);
-
-      compare1:
-	if (xstart < lstart)
-		goto compare2;
-
-	/* (lstart <= xstart) */
-
-	/* lxd is NOT covered by xad */
-	if (lend <= xstart) {
-		/*
-		 * get next lxd
-		 */
-		if (--nlxd == 0)
-			goto mapend;
-		lxd++;
-
-		lstart = offsetLXD(lxd);
-		llen = lengthLXD(lxd);
-		lend = lstart + llen;
-		if (lstart >= size)
-			goto mapend;
-
-		/* compare with the current xad */
-		goto compare1;
-	}
-	/* lxd is covered by xad */
-	else {			/* (xstart < lend) */
-
-		/* initialize new pxd */
-		pstart = xstart;
-		plen = min(lend - xstart, xlen);
-		paddr = xaddr;
-
-		goto cover;
-	}
-
-	/* (xstart < lstart) */
-      compare2:
-	/* lxd is covered by xad */
-	if (lstart < xend) {
-		/* initialize new pxd */
-		pstart = lstart;
-		plen = min(xend - lstart, llen);
-		paddr = xaddr + (lstart - xstart);
-
-		goto cover;
-	}
-	/* lxd is NOT covered by xad */
-	else {			/* (xend <= lstart) */
-
-		/*
-		 * get next xad
-		 *
-		 * linear search next xad covering lxd on
-		 * the current xad page, and then tree search
-		 */
-		if (index == le16_to_cpu(p->header.nextindex) - 1) {
-			if (p->header.flag & BT_ROOT)
-				goto mapend;
-
-			XT_PUTPAGE(mp);
-			goto search;
-		} else {
-			index++;
-			xad++;
-
-			/* compare with new xad */
-			goto compare;
-		}
-	}
-
-	/*
-	 * lxd is covered by xad and a new pxd has been initialized
-	 * (lstart <= xstart < lend) or (xstart < lstart < xend)
-	 */
-      cover:
-	/* finalize pxd corresponding to current xad */
-	XT_PUTENTRY(pxd, xad->flag, pstart, plen, paddr);
-
-	if (++npxd >= maxnpxd)
-		goto mapend;
-	pxd++;
-
-	/*
-	 * lxd is fully covered by xad
-	 */
-	if (lend <= xend) {
-		/*
-		 * get next lxd
-		 */
-		if (--nlxd == 0)
-			goto mapend;
-		lxd++;
-
-		lstart = offsetLXD(lxd);
-		llen = lengthLXD(lxd);
-		lend = lstart + llen;
-		if (lstart >= size)
-			goto mapend;
-
-		/*
-		 * test for old xad covering new lxd
-		 * (old xstart < new lstart)
-		 */
-		goto compare2;
-	}
-	/*
-	 * lxd is partially covered by xad
-	 */
-	else {			/* (xend < lend) */
-
-		/*
-		 * get next xad
-		 *
-		 * linear search next xad covering lxd on
-		 * the current xad page, and then next xad page search
-		 */
-		if (index == le16_to_cpu(p->header.nextindex) - 1) {
-			if (p->header.flag & BT_ROOT)
-				goto mapend;
-
-			if ((bn = le64_to_cpu(p->header.next)) == 0)
-				goto mapend;
-
-			XT_PUTPAGE(mp);
-
-			/* get next sibling page */
-			XT_GETPAGE(ip, bn, mp, PSIZE, p, rc);
-			if (rc)
-				return rc;
-
-			index = XTENTRYSTART;
-			xad = &p->xad[index];
-		} else {
-			index++;
-			xad++;
-		}
-
-		/*
-		 * test for new xad covering old lxd
-		 * (old lstart < new xstart)
-		 */
-		goto compare;
-	}
-
-      mapend:
-	xadlist->nxad = npxd;
-
-//out:
-	XT_PUTPAGE(mp);
-
-	return rc;
-}
-
-
 /*
  *	xtSearch()
  *

fs/jfs/jfs_xtree.h

@@ -110,8 +110,6 @@ typedef union {
  */
 extern int xtLookup(struct inode *ip, s64 lstart, s64 llen,
 		    int *pflag, s64 * paddr, int *plen, int flag);
-extern int xtLookupList(struct inode *ip, struct lxdlist * lxdlist,
-			struct xadlist * xadlist, int flag);
 extern void xtInitRoot(tid_t tid, struct inode *ip);
 extern int xtInsert(tid_t tid, struct inode *ip,
 		    int xflag, s64 xoff, int xlen, s64 * xaddrp, int flag);