vfs: Return -ENXIO for negative SEEK_HOLE / SEEK_DATA offsets

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@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: s/eof/i_size_read(inode)/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/fs/read_write.c b/fs/read_write.c
index 5ad4248..3649bfd 100644 (file)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -99,7 +99,7 @@ generic_file_llseek_size(struct file *file, loff_t offset, int origin,
                 * 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 *file, loff_t offset, int origin,
                 * 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;