Make BIO_PAGE_REFFED the same as FOLL_GET and BIO_PAGE_PINNED the same as
FOLL_PIN numerically so that the BIO_* flags can be passed directly to
page_put_unpin().
Provide a build-time assertion to check this.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
cc: Jens Axboe <axboe@xxxxxxxxx>
cc: Jan Kara <jack@xxxxxxx>
cc: Christoph Hellwig <hch@xxxxxx>
cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
cc: linux-block@xxxxxxxxxxxxxxx
---
block/bio.c | 3 +++
include/linux/blk_types.h | 1 +
include/linux/mm.h | 17 ++++++++++-------
3 files changed, 14 insertions(+), 7 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index 5b6a76c3e620..d8c636cefcdd 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1798,6 +1798,9 @@ static int __init init_bio(void)
{
int i;
+ BUILD_BUG_ON((1 << BIO_PAGE_REFFED) != FOLL_GET);
+ BUILD_BUG_ON((1 << BIO_PAGE_PINNED) != FOLL_PIN);
+
bio_integrity_init();
for (i = 0; i < ARRAY_SIZE(bvec_slabs); i++) {
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 86711fb0534a..42b40156c517 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -319,6 +319,7 @@ struct bio {
*/
enum {
BIO_PAGE_REFFED, /* Pages need refs putting (equivalent to FOLL_GET) */
+ BIO_PAGE_PINNED, /* Pages need unpinning (equivalent to FOLL_PIN) */
BIO_CLONED, /* doesn't own data */
BIO_BOUNCED, /* bio is a bounce bio */
BIO_QUIET, /* Make BIO Quiet */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 8e746a930945..f14edb192394 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 */
@@ -3098,6 +3098,9 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
#define FOLL_BUF_MASK FOLL_WRITE
/*
+ * FOLL_GET must be the same bit as BIO_FOLL_GET and FOLL_PIN must be the same
+ * bit as BIO_FOLL_PIN.
+ *
* FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each
* other. Here is what they mean, and how to use them:
*
