[PATCH] vfs: Support FALLOC_FL_NO_HIDE_STALE flag with fallocate

[Sig Shen]

FALLOC_FL_NO_HIDE_STALE flag must be set if user want to issue
a discard request for block devices. But vfs_fallocate() will
return with an error -EOPNOTSUPP indicating lack of support
if this flag is set.

fix it by allowing FALLOC_FL_NO_HIDE_STALE flag in vfs_fallocate

Fixes: 25f4c41415e5 ("block: implement (some of) fallocate for block devices")
Signed-off-by: Sig Shen <sigs...@synology.com>
---
 include/linux/falloc.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/falloc.h b/include/linux/falloc.h
index 674d59f..770a122 100644
--- a/include/linux/falloc.h
+++ b/include/linux/falloc.h
@@ -27,6 +27,7 @@ struct space_resv {
                                         FALLOC_FL_COLLAPSE_RANGE |     \
                                         FALLOC_FL_ZERO_RANGE |         \
                                         FALLOC_FL_INSERT_RANGE |       \
+                                        FALLOC_FL_NO_HIDE_STALE |      \
                                         FALLOC_FL_UNSHARE_RANGE)
 
 #endif /* _FALLOC_H_ */
-- 
2.7.4