[PATCH] Fix get_unmapped_area and fsync for hugetlb shm segments
This patch provides the following hugetlb-related fixes to the recent stacked
shm files changes:
- Update is_file_hugepages() so it will reconize hugetlb shm segments.
- get_unmapped_area must be called with the nested file struct to handle
the sfd->file->f_ops->get_unmapped_area == NULL case.
- The fsync f_op must be wrapped since it is specified in the hugetlbfs
f_ops.
This is based on proposed fixes from Eric Biederman that were debugged and
tested by me. Without it, attempting to use hugetlb shared memory segments
on powerpc (and likely ia64) will kill your box.
Signed-off-by: Adam Litke <agl@us.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: William Irwin <bill.irwin@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/shm.h b/include/linux/shm.h
index a2c896a..ad2e3af 100644
--- a/include/linux/shm.h
+++ b/include/linux/shm.h
@@ -96,12 +96,17 @@
#ifdef CONFIG_SYSVIPC
long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr);
+extern int is_file_shm_hugepages(struct file *file);
#else
static inline long do_shmat(int shmid, char __user *shmaddr,
int shmflg, unsigned long *addr)
{
return -ENOSYS;
}
+static inline int is_file_shm_hugepages(struct file *file)
+{
+ return 0;
+}
#endif
#endif /* __KERNEL__ */