[PATCHv5 16/36] thp: make thp_get_unmapped_area() respect S_HUGE_MODE

Kirill A. Shutemov
2016-11-29T11:22:44Z

We want mmap(NULL) to return PMD-aligned address if the inode can have
huge pages in page cache.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
mm/huge_memory.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index a15d566b14f6..9c6ba124ba50 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -518,10 +518,12 @@ unsigned long thp_get_unmapped_area(struct file *filp, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
loff_t off = (loff_t)pgoff << PAGE_SHIFT;
+ struct inode *inode = filp->f_mapping->host;

if (addr)
goto out;
- if (!IS_DAX(filp->f_mapping->host) || !IS_ENABLED(CONFIG_FS_DAX_PMD))
+ if ((inode->i_flags & S_HUGE_MODE) == S_HUGE_NEVER &&
+ (!IS_DAX(inode) || !IS_ENABLED(CONFIG_FS_DAX_PMD)))
goto out;

addr = __thp_get_unmapped_area(filp, len, off, flags, PMD_SIZE);