Readahead was factored to call generic_fadvise. That refactor added an S_ISREG
restriction which broke readahead on block devices.
This change swaps out the existing restrictions with an FMODE_LSEEK check to
fix block device readahead.
The readahead01.c and readahead02.c tests pass in ltp/testcases/...
Fixes: 3d8f7615319b ("vfs: implement readahead(2) using POSIX_FADV_WILLNEED")
Reviewed-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Reuben Hawkins <reubenhwk@xxxxxxxxx>
---
mm/readahead.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/mm/readahead.c b/mm/readahead.c
index e815c114de21..0ff6fffe3c84 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -734,8 +734,7 @@ ssize_t ksys_readahead(int fd, loff_t offset, size_t count)
* on this file, then we must return -EINVAL.
*/
ret = -EINVAL;
- if (!f.file->f_mapping || !f.file->f_mapping->a_ops ||
- !S_ISREG(file_inode(f.file)->i_mode))
+ if (!(f.file->f_mode & FMODE_LSEEK))
goto out;
ret = vfs_fadvise(f.file, offset, count, POSIX_FADV_WILLNEED);
--
2.34.1
