[PATCH 3.16 062/204] vfs: Return -ENXIO for negative SEEK_HOLE / SEEK_DATA offsets

From: Ben Hutchings
Date: Thu Dec 28 2017 - 12:32:56 EST


3.16.52-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>
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
@@ -116,7 +116,7 @@ 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 >= eof)
+ if ((unsigned long long)offset >= eof)
return -ENXIO;
break;
case SEEK_HOLE:
@@ -124,7 +124,7 @@ 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 >= eof)
+ if ((unsigned long long)offset >= eof)
return -ENXIO;
offset = eof;
break;