[PATCH 3.2 24/94] vfs: Return -ENXIO for negative SEEK_HOLE / SEEK_DATA offsets

[Ben Hutchings]

3.2.97-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Andreas Gruenbacher <agruenba@xxxxxxxxxx>

commit fc46820b27a2d9a46f7e90c9ceb4a64a1bc5fab8 upstream.

In generic_file_llseek_size, return -ENXIO for negative offsets as well
as offsets beyond EOF.  This affects filesystems which don't implement
SEEK_HOLE / SEEK_DATA internally, possibly because they don't support
holes.

Fixes xfstest generic/448.

Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
[bwh: Backported to 3.2: s/eof/i_size_read(inode)/]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 fs/read_write.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -99,7 +99,7 @@ generic_file_llseek_size(struct file *fi
 		 * In the generic case the entire file is data, so as long as
 		 * offset isn't at the end of the file then the offset is data.
 		 */
-		if (offset >= i_size_read(inode))
+		if ((unsigned long long)offset >= i_size_read(inode))
 			return -ENXIO;
 		break;
 	case SEEK_HOLE:
@@ -107,7 +107,7 @@ generic_file_llseek_size(struct file *fi
 		 * There is a virtual hole at the end of the file, so as long as
 		 * offset isn't i_size or larger, return i_size.
 		 */
-		if (offset >= i_size_read(inode))
+		if ((unsigned long long)offset >= i_size_read(inode))
 			return -ENXIO;
 		offset = i_size_read(inode);
 		break;