Renumber FOLL_GET and FOLL_PIN down to bit 0 and 1 respectively so that
they are coincidentally the same as BIO_PAGE_REFFED and BIO_PAGE_PINNED and
also so that they can be stored in the bottom two bits of a page pointer
(something I'm looking at for zerocopy socket fragments).
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: Christoph Hellwig <hch@lst.de>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
---
include/linux/mm.h | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index f1cf8f4eb946..33c9eacd9548 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3074,12 +3074,13 @@ static inline vm_fault_t vmf_error(int err)
struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
unsigned int foll_flags);
-#define FOLL_WRITE 0x01 /* check pte is writable */
-#define FOLL_TOUCH 0x02 /* mark page accessed */
-#define FOLL_GET 0x04 /* do get_page on page */
-#define FOLL_DUMP 0x08 /* give error on hole if it would be zero */
-#define FOLL_FORCE 0x10 /* get_user_pages read/write w/o permission */
-#define FOLL_NOWAIT 0x20 /* if a disk transfer is needed, start the IO
+#define FOLL_GET 0x01 /* do get_page on page (equivalent to BIO_FOLL_GET) */
+#define FOLL_PIN 0x02 /* pages must be released via unpin_user_page */
+#define FOLL_WRITE 0x04 /* check pte is writable */
+#define FOLL_TOUCH 0x08 /* mark page accessed */
+#define FOLL_DUMP 0x10 /* give error on hole if it would be zero */
+#define FOLL_FORCE 0x20 /* get_user_pages read/write w/o permission */
+#define FOLL_NOWAIT 0x40 /* if a disk transfer is needed, start the IO
* and return without waiting upon it */
#define FOLL_NOFAULT 0x80 /* do not fault in pages */
#define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */
@@ -3088,7 +3089,6 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
#define FOLL_ANON 0x8000 /* don't do file mappings */
#define FOLL_LONGTERM 0x10000 /* mapping lifetime is indefinite: see below */
#define FOLL_SPLIT_PMD 0x20000 /* split huge pmd before returning */
-#define FOLL_PIN 0x40000 /* pages must be released via unpin_user_page */
#define FOLL_FAST_ONLY 0x80000 /* gup_fast: prevent fall-back to slow gup */
#define FOLL_PCI_P2PDMA 0x100000 /* allow returning PCI P2PDMA pages */
#define FOLL_INTERRUPTIBLE 0x200000 /* allow interrupts from generic signals */