fs: don't open code lru_to_page()

Multiple filesystems open code lru_to_page().  Rectify this by moving
the macro from mm_inline (which is specific to lru stuff) to the more
generic mm.h header and start using the macro where appropriate.

No functional changes.

Link: http://lkml.kernel.org/r/20181129104810.23361-1-nborisov@suse.com
Link: https://lkml.kernel.org/r/20181129075301.29087-1-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Pankaj gupta <pagupta@redhat.com>
Acked-by: "Yan, Zheng" <zyan@redhat.com>		[ceph]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/afs/file.c

@@ -17,6 +17,7 @@
 #include <linux/writeback.h>
 #include <linux/gfp.h>
 #include <linux/task_io_accounting_ops.h>
+#include <linux/mm.h>
 #include "internal.h"
 
 static int afs_file_mmap(struct file *file, struct vm_area_struct *vma);
@@ -441,7 +442,7 @@ static int afs_readpages_one(struct file *file, struct address_space *mapping,
 	/* Count the number of contiguous pages at the front of the list.  Note
 	 * that the list goes prev-wards rather than next-wards.
 	 */
-	first = list_entry(pages->prev, struct page, lru);
+	first = lru_to_page(pages);
 	index = first->index + 1;
 	n = 1;
 	for (p = first->lru.prev; p != pages; p = p->prev) {
@@ -473,7 +474,7 @@ static int afs_readpages_one(struct file *file, struct address_space *mapping,
 	 * page at the end of the file.
 	 */
 	do {
-		page = list_entry(pages->prev, struct page, lru);
+		page = lru_to_page(pages);
 		list_del(&page->lru);
 		index = page->index;
 		if (add_to_page_cache_lru(page, mapping, index,

fs/btrfs/extent_io.c

@@ -4103,8 +4103,7 @@ int extent_readpages(struct address_space *mapping, struct list_head *pages,
 
 	while (!list_empty(pages)) {
 		for (nr = 0; nr < ARRAY_SIZE(pagepool) && !list_empty(pages);) {
-			struct page *page = list_entry(pages->prev,
-						       struct page, lru);
+			struct page *page = lru_to_page(pages);
 
 			prefetchw(&page->flags);
 			list_del(&page->lru);

fs/ceph/addr.c

@@ -306,7 +306,7 @@ static int start_read(struct inode *inode, struct ceph_rw_context *rw_ctx,
 	struct ceph_osd_client *osdc =
 		&ceph_inode_to_client(inode)->client->osdc;
 	struct ceph_inode_info *ci = ceph_inode(inode);
-	struct page *page = list_entry(page_list->prev, struct page, lru);
+	struct page *page = lru_to_page(page_list);
 	struct ceph_vino vino;
 	struct ceph_osd_request *req;
 	u64 off;
@@ -333,8 +333,7 @@ static int start_read(struct inode *inode, struct ceph_rw_context *rw_ctx,
 			if (got)
 				ceph_put_cap_refs(ci, got);
 			while (!list_empty(page_list)) {
-				page = list_entry(page_list->prev,
-						  struct page, lru);
+				page = lru_to_page(page_list);
 				list_del(&page->lru);
 				put_page(page);
 			}

fs/cifs/file.c

@@ -33,6 +33,7 @@
 #include <linux/mount.h>
 #include <linux/slab.h>
 #include <linux/swap.h>
+#include <linux/mm.h>
 #include <asm/div64.h>
 #include "cifsfs.h"
 #include "cifspdu.h"
@@ -3964,7 +3965,7 @@ readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
 
 	INIT_LIST_HEAD(tmplist);
 
-	page = list_entry(page_list->prev, struct page, lru);
+	page = lru_to_page(page_list);
 
 	/*
 	 * Lock the page and put it in the cache. Since no one else

fs/ext4/readpage.c

@@ -128,7 +128,7 @@ int ext4_mpage_readpages(struct address_space *mapping,
 
 		prefetchw(&page->flags);
 		if (pages) {
-			page = list_entry(pages->prev, struct page, lru);
+			page = lru_to_page(pages);
 			list_del(&page->lru);
 			if (add_to_page_cache_lru(page, mapping, page->index,
 				  readahead_gfp_mask(mapping)))

fs/ocfs2/aops.c

@@ -30,6 +30,7 @@
 #include <linux/quotaops.h>
 #include <linux/blkdev.h>
 #include <linux/uio.h>
+#include <linux/mm.h>
 
 #include <cluster/masklog.h>
 
@@ -397,7 +398,7 @@ static int ocfs2_readpages(struct file *filp, struct address_space *mapping,
 	 * Check whether a remote node truncated this file - we just
 	 * drop out in that case as it's not worth handling here.
 	 */
-	last = list_entry(pages->prev, struct page, lru);
+	last = lru_to_page(pages);
 	start = (loff_t)last->index << PAGE_SHIFT;
 	if (start >= i_size_read(inode))
 		goto out_unlock;

fs/orangefs/inode.c

@@ -77,7 +77,7 @@ static int orangefs_readpages(struct file *file,
 	for (page_idx = 0; page_idx < nr_pages; page_idx++) {
 		struct page *page;
 
-		page = list_entry(pages->prev, struct page, lru);
+		page = lru_to_page(pages);
 		list_del(&page->lru);
 		if (!add_to_page_cache(page,
 				       mapping,

include/linux/mm.h

@@ -171,6 +171,8 @@ extern int overcommit_kbytes_handler(struct ctl_table *, int, void __user *,
 /* test whether an address (unsigned long or pointer) is aligned to PAGE_SIZE */
 #define PAGE_ALIGNED(addr)	IS_ALIGNED((unsigned long)(addr), PAGE_SIZE)
 
+#define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
+
 /*
  * Linux kernel virtual memory manager primitives.
  * The idea being to have a "virtual" mm in the same way

include/linux/mm_inline.h

@@ -124,7 +124,4 @@ static __always_inline enum lru_list page_lru(struct page *page)
 	}
 	return lru;
 }
-
-#define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
-
 #endif

mm/swap.c

@@ -126,7 +126,7 @@ void put_pages_list(struct list_head *pages)
 	while (!list_empty(pages)) {
 		struct page *victim;
 
-		victim = list_entry(pages->prev, struct page, lru);
+		victim = lru_to_page(pages);
 		list_del(&victim->lru);
 		put_page(victim);
 	}