[PATCH 1/4] fsx: allow zero range operations to cross eof

[fdmanana@kernel.org]

From: Filipe Manana <fdmanana@suse.com>

Currently we are limiting the range for zero range operations to stay
within the i_size boundary. This is not optimal because like this we lose
coverage of the filesystem's zero range implementation, since zero range
operations are allowed to cross the i_size. Fix this by limiting the range
to 'maxfilelen' and not 'file_size', and update the 'file_size' after each
zero range operation if needed.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 ltp/fsx.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/ltp/fsx.c b/ltp/fsx.c
index 9d598a4f..56479eda 100644
--- a/ltp/fsx.c
+++ b/ltp/fsx.c
@@ -1244,6 +1244,17 @@ do_zero_range(unsigned offset, unsigned length, int keep_size)
 	}
 
 	memset(good_buf + offset, '\0', length);
+
+	if (!keep_size && end_offset > file_size) {
+		/*
+		 * If there's a gap between the old file size and the offset of
+		 * the zero range operation, fill the gap with zeroes.
+		 */
+		if (offset > file_size)
+			memset(good_buf + file_size, '\0', offset - file_size);
+
+		file_size = end_offset;
+	}
 }
 
 #else
@@ -2141,7 +2152,7 @@ have_op:
 		do_punch_hole(offset, size);
 		break;
 	case OP_ZERO_RANGE:
-		TRIM_OFF_LEN(offset, size, file_size);
+		TRIM_OFF_LEN(offset, size, maxfilelen);
 		do_zero_range(offset, size, keep_size);
 		break;
 	case OP_COLLAPSE_RANGE:
-- 
2.11.0