1 files changed, 55 insertions, 20 deletions

diff --git a/fs/ioctl.c b/fs/ioctl.c
index ac2d47e43926..82d9c42b8bac 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);