[PATCHv6 16/37] thp: make thp_get_unmapped_area() respect S_HUGE_MODE

[Kirill A. Shutemov]

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.shute...@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 55aee62e8444..2b1d8d13e2c3 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -528,10 +528,12 @@ 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);
-- 
2.11.0