xfs: return -ENOSPC from xfs_rtallocate_*

Just return -ENOSPC instead of returning 0 and setting the return rt
extent number to NULLRTEXTNO.  This is turn removes all users of
NULLRTEXTNO, so remove that as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

2 files changed, 71 insertions, 141 deletions

diff --git a/fs/xfs/libxfs/xfs_types.h b/fs/xfs/libxfs/xfs_types.h
index 035bf703d719..20b5375f2d9c 100644
--- a/fs/xfs/libxfs/xfs_types.h
+++ b/fs/xfs/libxfs/xfs_types.h
@@ -51,7 +51,6 @@ typedef void *		xfs_failaddr_t;
 #define	NULLRFSBLOCK	((xfs_rfsblock_t)-1)
 #define	NULLRTBLOCK	((xfs_rtblock_t)-1)
 #define	NULLFILEOFF	((xfs_fileoff_t)-1)
-#define	NULLRTEXTNO	((xfs_rtxnum_t)-1)
 
 #define	NULLAGBLOCK	((xfs_agblock_t)-1)
 #define	NULLAGNUMBER	((xfs_agnumber_t)-1)
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 35380d0cfe9b..a810482339ad 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -156,17 +156,17 @@ xfs_rtallocate_range(
 	 * properly update the summary.
 	 */
 	error = xfs_rtfind_back(args, start, 0, &preblock);
-	if (error) {
+	if (error)
 		return error;
-	}
+
 	/*
 	 * Find the next allocated block (end of free extent).
 	 */
 	error = xfs_rtfind_forw(args, end, mp->m_sb.sb_rextents - 1,
 			&postblock);
-	if (error) {
+	if (error)
 		return error;
-	}
+
 	/*
 	 * Decrement the summary information corresponding to the entire
 	 * (old) free extent.
@@ -174,9 +174,9 @@ xfs_rtallocate_range(
 	error = xfs_rtmodify_summary(args,
 			XFS_RTBLOCKLOG(postblock + 1 - preblock),
 			xfs_rtx_to_rbmblock(mp, preblock), -1);
-	if (error) {
+	if (error)
 		return error;
-	}
+
 	/*
 	 * If there are blocks not being allocated at the front of the
 	 * old extent, add summary data for them to be free.
@@ -185,10 +185,10 @@ xfs_rtallocate_range(
 		error = xfs_rtmodify_summary(args,
 				XFS_RTBLOCKLOG(start - preblock),
 				xfs_rtx_to_rbmblock(mp, preblock), 1);
-		if (error) {
+		if (error)
 			return error;
-		}
 	}
+
 	/*
 	 * If there are blocks not being allocated at the end of the
 	 * old extent, add summary data for them to be free.
@@ -197,15 +197,14 @@ xfs_rtallocate_range(
 		error = xfs_rtmodify_summary(args,
 				XFS_RTBLOCKLOG(postblock - end),
 				xfs_rtx_to_rbmblock(mp, end + 1), 1);
-		if (error) {
+		if (error)
 			return error;
-		}
 	}
+
 	/*
 	 * Modify the bitmap to mark this extent allocated.
 	 */
-	error = xfs_rtmodify_range(args, start, len, 0);
-	return error;
+	return xfs_rtmodify_range(args, start, len, 0);
 }
 
 /*
@@ -267,17 +266,17 @@ xfs_rtallocate_extent_block(
 		 * If it's not so then next will contain the first non-free.
 		 */
 		error = xfs_rtcheck_range(args, i, maxlen, 1, &next, &stat);
-		if (error) {
+		if (error)
 			return error;
-		}
+
 		if (stat) {
 			/*
 			 * i for maxlen is all free, allocate and return that.
 			 */
 			error = xfs_rtallocate_range(args, i, maxlen);
-			if (error) {
+			if (error)
 				return error;
-			}
+
 			*len = maxlen;
 			*rtx = i;
 			return 0;
@@ -302,9 +301,8 @@ xfs_rtallocate_extent_block(
 		 */
 		if (next < end) {
 			error = xfs_rtfind_forw(args, next, end, &i);
-			if (error) {
+			if (error)
 				return error;
-			}
 		} else
 			break;
 	}
@@ -327,9 +325,8 @@ xfs_rtallocate_extent_block(
 		 * Allocate besti for bestlen & return that.
 		 */
 		error = xfs_rtallocate_range(args, besti, bestlen);
-		if (error) {
+		if (error)
 			return error;
-		}
 		*len = bestlen;
 		*rtx = besti;
 		return 0;
@@ -338,8 +335,7 @@ xfs_rtallocate_extent_block(
 	 * Allocation failed.  Set *nextp to the next block to try.
 	 */
 	*nextp = next;
-	*rtx = NULLRTEXTNO;
-	return 0;
+	return -ENOSPC;
 }
 
 /*
@@ -369,17 +365,16 @@ xfs_rtallocate_extent_exact(
 	 * Check if the range in question (for maxlen) is free.
 	 */
 	error = xfs_rtcheck_range(args, start, maxlen, 1, &next, &isfree);
-	if (error) {
+	if (error)
 		return error;
-	}
+
 	if (isfree) {
 		/*
 		 * If it is, allocate it and return success.
 		 */
 		error = xfs_rtallocate_range(args, start, maxlen);
-		if (error) {
+		if (error)
 			return error;
-		}
 		*len = maxlen;
 		*rtx = start;
 		return 0;
@@ -388,33 +383,23 @@ xfs_rtallocate_extent_exact(
 	 * If not, allocate what there is, if it's at least minlen.
 	 */
 	maxlen = next - start;
-	if (maxlen < minlen) {
-		/*
-		 * Failed, return failure status.
-		 */
-		*rtx = NULLRTEXTNO;
-		return 0;
-	}
+	if (maxlen < minlen)
+		return -ENOSPC;
+
 	/*
 	 * Trim off tail of extent, if prod is specified.
 	 */
 	if (prod > 1 && (i = maxlen % prod)) {
 		maxlen -= i;
-		if (maxlen < minlen) {
-			/*
-			 * Now we can't do it, return failure status.
-			 */
-			*rtx = NULLRTEXTNO;
-			return 0;
-		}
+		if (maxlen < minlen)
+			return -ENOSPC;
 	}
 	/*
 	 * Allocate what we can and return it.
 	 */
 	error = xfs_rtallocate_range(args, start, maxlen);
-	if (error) {
+	if (error)
 		return error;
-	}
 	*len = maxlen;
 	*rtx = start;
 	return 0;
@@ -443,7 +428,6 @@ xfs_rtallocate_extent_near(
 	int			j;	/* secondary loop control */
 	int			log2len; /* log2 of minlen */
 	xfs_rtxnum_t		n;	/* next rtext to try */
-	xfs_rtxnum_t		r;	/* result rtext */
 
 	ASSERT(minlen % prod == 0);
 	ASSERT(maxlen % prod == 0);
@@ -457,26 +441,18 @@ xfs_rtallocate_extent_near(
 
 	/* Make sure we don't run off the end of the rt volume. */
 	maxlen = xfs_rtallocate_clamp_len(mp, start, maxlen, prod);
-	if (maxlen < minlen) {
-		*rtx = NULLRTEXTNO;
-		return 0;
-	}
+	if (maxlen < minlen)
+		return -ENOSPC;
 
 	/*
 	 * Try the exact allocation first.
 	 */
 	error = xfs_rtallocate_extent_exact(args, start, minlen, maxlen, len,
-			prod, &r);
-	if (error) {
+			prod, rtx);
+	if (error != -ENOSPC)
 		return error;
-	}
-	/*
-	 * If the exact allocation worked, return that.
-	 */
-	if (r != NULLRTEXTNO) {
-		*rtx = r;
-		return 0;
-	}
+
+
 	bbno = xfs_rtx_to_rbmblock(mp, start);
 	i = 0;
 	j = -1;
@@ -492,9 +468,9 @@ xfs_rtallocate_extent_near(
 		 */
 		error = xfs_rtany_summary(args, log2len, mp->m_rsumlevels - 1,
 				bbno + i, &maxlog);
-		if (error) {
+		if (error)
 			return error;
-		}
+
 		/*
 		 * If there are any useful extents starting here, try
 		 * allocating one.
@@ -513,17 +489,9 @@ xfs_rtallocate_extent_near(
 				 */
 				error = xfs_rtallocate_extent_block(args,
 						bbno + i, minlen, maxavail, len,
-						&n, prod, &r);
-				if (error) {
+						&n, prod, rtx);
+				if (error != -ENOSPC)
 					return error;
-				}
-				/*
-				 * If it worked, return it.
-				 */
-				if (r != NULLRTEXTNO) {
-					*rtx = r;
-					return 0;
-				}
 			}
 			/*
 			 * On the negative side of the starting location.
@@ -557,17 +525,9 @@ xfs_rtallocate_extent_near(
 					error = xfs_rtallocate_extent_block(args,
 							bbno + j, minlen,
 							maxavail, len, &n, prod,
-							&r);
-					if (error) {
+							rtx);
+					if (error != -ENOSPC)
 						return error;
-					}
-					/*
-					 * If it works, return the extent.
-					 */
-					if (r != NULLRTEXTNO) {
-						*rtx = r;
-						return 0;
-					}
 				}
 			}
 		}
@@ -601,8 +561,7 @@ xfs_rtallocate_extent_near(
 		else
 			break;
 	}
-	*rtx = NULLRTEXTNO;
-	return 0;
+	return -ENOSPC;
 }
 
 /*
@@ -624,7 +583,6 @@ xfs_rtallocate_extent_size(
 	xfs_fileoff_t		i;	/* bitmap block number */
 	int			l;	/* level number (loop control) */
 	xfs_rtxnum_t		n;	/* next rtext to be tried */
-	xfs_rtxnum_t		r;	/* result rtext number */
 	xfs_suminfo_t		sum;	/* summary information for extents */
 
 	ASSERT(minlen % prod == 0);
@@ -647,9 +605,8 @@ xfs_rtallocate_extent_size(
 			 * Get the summary for this level/block.
 			 */
 			error = xfs_rtget_summary(args, l, i, &sum);
-			if (error) {
+			if (error)
 				return error;
-			}
 			/*
 			 * Nothing there, on to the next block.
 			 */
@@ -659,17 +616,9 @@ xfs_rtallocate_extent_size(
 			 * Try allocating the extent.
 			 */
 			error = xfs_rtallocate_extent_block(args, i, maxlen,
-					maxlen, len, &n, prod, &r);
-			if (error) {
+					maxlen, len, &n, prod, rtx);
+			if (error != -ENOSPC)
 				return error;
-			}
-			/*
-			 * If it worked, return that.
-			 */
-			if (r != NULLRTEXTNO) {
-				*rtx = r;
-				return 0;
-			}
 			/*
 			 * If the "next block to try" returned from the
 			 * allocator is beyond the next bitmap block,
@@ -683,10 +632,8 @@ xfs_rtallocate_extent_size(
 	 * Didn't find any maxlen blocks.  Try smaller ones, unless
 	 * we're asking for a fixed size extent.
 	 */
-	if (minlen > --maxlen) {
-		*rtx = NULLRTEXTNO;
-		return 0;
-	}
+	if (minlen > --maxlen)
+		return -ENOSPC;
 	ASSERT(minlen != 0);
 	ASSERT(maxlen != 0);
 
@@ -705,9 +652,9 @@ xfs_rtallocate_extent_size(
 			 * Get the summary information for this level/block.
 			 */
 			error =	xfs_rtget_summary(args, l, i, &sum);
-			if (error) {
+			if (error)
 				return error;
-			}
+
 			/*
 			 * If nothing there, go on to next.
 			 */
@@ -721,17 +668,10 @@ xfs_rtallocate_extent_size(
 			error = xfs_rtallocate_extent_block(args, i,
 					XFS_RTMAX(minlen, 1 << l),
 					XFS_RTMIN(maxlen, (1 << (l + 1)) - 1),
-					len, &n, prod, &r);
-			if (error) {
+					len, &n, prod, rtx);
+			if (error != -ENOSPC)
 				return error;
-			}
-			/*
-			 * If it worked, return that extent.
-			 */
-			if (r != NULLRTEXTNO) {
-				*rtx = r;
-				return 0;
-			}
+
 			/*
 			 * If the "next block to try" returned from the
 			 * allocator is beyond the next bitmap block,
@@ -744,8 +684,7 @@ xfs_rtallocate_extent_size(
 	/*
 	 * Got nothing, return failure.
 	 */
-	*rtx = NULLRTEXTNO;
-	return 0;
+	return -ENOSPC;
 }
 
 /*
@@ -1182,14 +1121,13 @@ xfs_rtallocate_extent(
 	xfs_rtxlen_t		*len,	/* out: actual length allocated */
 	int			wasdel,	/* was a delayed allocation extent */
 	xfs_rtxlen_t		prod,	/* extent product factor */
-	xfs_rtxnum_t		*rtblock) /* out: start rtext allocated */
+	xfs_rtxnum_t		*rtx)	/* out: start rtext allocated */
 {
 	struct xfs_rtalloc_args	args = {
 		.mp		= tp->t_mountp,
 		.tp		= tp,
 	};
 	int			error;	/* error value */
-	xfs_rtxnum_t		r;	/* result allocated rtext */
 
 	ASSERT(xfs_isilocked(args.mp->m_rbmip, XFS_ILOCK_EXCL));
 	ASSERT(minlen > 0 && minlen <= maxlen);
@@ -1204,42 +1142,35 @@ xfs_rtallocate_extent(
 			maxlen -= i;
 		if ((i = minlen % prod))
 			minlen += prod - i;
-		if (maxlen < minlen) {
-			*rtblock = NULLRTEXTNO;
-			return 0;
-		}
+		if (maxlen < minlen)
+			return -ENOSPC;
 	}
 
 retry:
 	if (start == 0) {
 		error = xfs_rtallocate_extent_size(&args, minlen,
-				maxlen, len, prod, &r);
+				maxlen, len, prod, rtx);
 	} else {
 		error = xfs_rtallocate_extent_near(&args, start, minlen,
-				maxlen, len, prod, &r);
+				maxlen, len, prod, rtx);
 	}
-
 	xfs_rtbuf_cache_relse(&args);
-	if (error)
+	if (error) {
+		if (error == -ENOSPC && prod > 1) {
+			prod = 1;
+			goto retry;
+		}
 		return error;
+	}
 
 	/*
 	 * If it worked, update the superblock.
 	 */
-	if (r != NULLRTEXTNO) {
-		long	slen = (long)*len;
-
-		ASSERT(*len >= minlen && *len <= maxlen);
-		if (wasdel)
-			xfs_trans_mod_sb(tp, XFS_TRANS_SB_RES_FREXTENTS, -slen);
-		else
-			xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS, -slen);
-	} else if (prod > 1) {
-		prod = 1;
-		goto retry;
-	}
-
-	*rtblock = r;
+	ASSERT(*len >= minlen && *len <= maxlen);
+	if (wasdel)
+		xfs_trans_mod_sb(tp, XFS_TRANS_SB_RES_FREXTENTS, -(long)*len);
+	else
+		xfs_trans_mod_sb(tp, XFS_TRANS_SB_FREXTENTS, -(long)*len);
 	return 0;
 }
 
@@ -1553,16 +1484,16 @@ retry:
 	raminlen = max_t(xfs_rtxlen_t, 1, xfs_extlen_to_rtxlen(mp, minlen));
 	error = xfs_rtallocate_extent(ap->tp, rtx, raminlen, ralen, &ralen,
 			ap->wasdel, prod, &rtx);
-	if (error)
-		return error;
-
-	if (rtx != NULLRTEXTNO) {
+	if (!error) {
 		ap->blkno = xfs_rtx_to_rtb(mp, rtx);
 		ap->length = xfs_rtxlen_to_extlen(mp, ralen);
 		xfs_bmap_alloc_account(ap);
 		return 0;
 	}
 
+	if (error != -ENOSPC)
+		return error;
+
 	if (align > mp->m_sb.sb_rextsize) {
 		/*
 		 * We previously enlarged the request length to try to satisfy