1 files changed, 55 insertions, 20 deletions

diff --git a/fs/ioctl.c b/fs/ioctl.c
index ac2d47e..82d9c42 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -258,7 +258,7 @@ int __generic_block_fiemap(struct inode *inode,
 	long long length = 0, map_len = 0;
 	u64 logical = 0, phys = 0, size = 0;
 	u32 flags = FIEMAP_EXTENT_MERGED;
-	int ret = 0;
+	int ret = 0, past_eof = 0, whole_file = 0;
 
 	if ((ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC)))
 		return ret;
@@ -266,6 +266,9 @@ int __generic_block_fiemap(struct inode *inode,
 	start_blk = logical_to_blk(inode, start);
 
 	length = (long long)min_t(u64, len, i_size_read(inode));
+	if (length < len)
+		whole_file = 1;
+
 	map_len = length;
 
 	do {
@@ -282,11 +285,26 @@ int __generic_block_fiemap(struct inode *inode,
 
 		/* HOLE */
 		if (!buffer_mapped(&tmp)) {
+			length -= blk_to_logical(inode, 1);
+			start_blk++;
+
+			/*
+			 * we want to handle the case where there is an
+			 * allocated block at the front of the file, and then
+			 * nothing but holes up to the end of the file properly,
+			 * to make sure that extent at the front gets properly
+			 * marked with FIEMAP_EXTENT_LAST
+			 */
+			if (!past_eof &&
+			    blk_to_logical(inode, start_blk) >=
+			    blk_to_logical(inode, 0)+i_size_read(inode))
+				past_eof = 1;
+
 			/*
 			 * first hole after going past the EOF, this is our
 			 * last extent
 			 */
-			if (length <= 0) {
+			if (past_eof && size) {
 				flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST;
 				ret = fiemap_fill_next_extent(fieinfo, logical,
 							      phys, size,
@@ -294,15 +312,37 @@ int __generic_block_fiemap(struct inode *inode,
 				break;
 			}
 
-			length -= blk_to_logical(inode, 1);
-
 			/* if we have holes up to/past EOF then we're done */
-			if (length <= 0)
+			if (length <= 0 || past_eof)
 				break;
-
-			start_blk++;
 		} else {
-			if (length <= 0 && size) {
+			/*
+			 * we have gone over the length of what we wanted to
+			 * map, and it wasn't the entire file, so add the extent
+			 * we got last time and exit.
+			 *
+			 * This is for the case where say we want to map all the
+			 * way up to the second to the last block in a file, but
+			 * the last block is a hole, making the second to last
+			 * block FIEMAP_EXTENT_LAST.  In this case we want to
+			 * see if there is a hole after the second to last block
+			 * so we can mark it properly.  If we found data after
+			 * we exceeded the length we were requesting, then we
+			 * are good to go, just add the extent to the fieinfo
+			 * and break
+			 */
+			if (length <= 0 && !whole_file) {
+				ret = fiemap_fill_next_extent(fieinfo, logical,
+							      phys, size,
+							      flags);
+				break;
+			}
+
+			/*
+			 * if size != 0 then we know we already have an extent
+			 * to add, so add it.
+			 */
+			if (size) {
 				ret = fiemap_fill_next_extent(fieinfo, logical,
 							      phys, size,
 							      flags);
@@ -319,19 +359,14 @@ int __generic_block_fiemap(struct inode *inode,
 			start_blk += logical_to_blk(inode, size);
 
 			/*
-			 * if we are past the EOF we need to loop again to see
-			 * if there is a hole so we can mark this extent as the
-			 * last one, and if not keep mapping things until we
-			 * find a hole, or we run out of slots in the extent
-			 * array
+			 * If we are past the EOF, then we need to make sure as
+			 * soon as we find a hole that the last extent we found
+			 * is marked with FIEMAP_EXTENT_LAST
 			 */
-			if (length <= 0)
-				continue;
-
-			ret = fiemap_fill_next_extent(fieinfo, logical, phys,
-						      size, flags);
-			if (ret)
-				break;
+			if (!past_eof &&
+			    logical+size >=
+			    blk_to_logical(inode, 0)+i_size_read(inode))
+				past_eof = 1;
 		}
 		cond_resched();
 	} while (1);