mm: remove nopage

Nothing in the tree uses nopage any more. Remove support for it in the core mm code and documentation (and a few stray references to it in comments). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: remove nopage
Nothing in the tree uses nopage any more. Remove support for it in the core mm code and documentation (and a few stray references to it in comments). Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nick Piggin · Linus Torvalds
1 parent 4d3d5b41a7
Showing 9 changed files with 11 additions and 43 deletions Side-by-side Diff
Documentation/feature-removal-schedule.txt
Documentation/filesystems/Locking
drivers/media/video/vino.c
drivers/video/vermilion/vermilion.c
fs/gfs2/ops_address.c
include/linux/mm.h
mm/memory.c
mm/mincore.c
mm/rmap.c
@@ -128,15 +128,6 @@
  
 ---------------------------
  
-What:	vm_ops.nopage
-When:	Soon, provided in-kernel callers have been converted
-Why:	This interface is replaced by vm_ops.fault, but it has been around
-	forever, is used by a lot of drivers, and doesn't cost much to
-	maintain.
-Who:	Nick Piggin <npiggin@suse.de>
-
----------------------------
-
 What:	PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
 When:	October 2008
 Why:	The stacking of class devices makes these values misleading and
@@ -511,7 +511,6 @@
 	void (*open)(struct vm_area_struct*);
 	void (*close)(struct vm_area_struct*);
 	int (*fault)(struct vm_area_struct*, struct vm_fault *);
-	struct page *(*nopage)(struct vm_area_struct*, unsigned long, int *);
 	int (*page_mkwrite)(struct vm_area_struct *, struct page *);
  
 locking rules:
@@ -519,7 +518,6 @@
 open:		no	yes
 close:		no	yes
 fault:		no	yes
-nopage:		no	yes
 page_mkwrite:	no	yes		no
  
 	->page_mkwrite() is called when a previously read-only page is
@@ -537,5 +535,4 @@
  
 ipc/shm.c::shm_delete() - may need BKL.
 ->read() and ->write() in many drivers are (probably) missing BKL.
-drivers/sgi/char/graphics.c::sgi_graphics_nopage() - may need BKL.
@@ -13,7 +13,7 @@
 /*
  * TODO:
  * - remove "mark pages reserved-hacks" from memory allocation code
- *   and implement nopage()
+ *   and implement fault()
  * - check decimation, calculating and reporting image size when
  *   using decimation
  * - implement read(), user mode buffers and overlay (?)
@@ -112,8 +112,9 @@
  
 	/*
 	 * It seems like __get_free_pages only ups the usage count
-	 * of the first page. This doesn't work with nopage mapping, so
-	 * up the usage count once more.
+	 * of the first page. This doesn't work with fault mapping, so
+	 * up the usage count once more (XXX: should use split_page or
+	 * compound page).
 	 */
  
 	memset((void *)va->logical, 0x00, va->size);
@@ -438,7 +438,7 @@
 	int error;
  
 	/*
-	 * Due to the order of unstuffing files and ->nopage(), we can be
+	 * Due to the order of unstuffing files and ->fault(), we can be
 	 * asked for a zero page in the case of a stuffed file being extended,
 	 * so we need to supply one here. It doesn't happen often.
 	 */
@@ -164,8 +164,6 @@
 	void (*open)(struct vm_area_struct * area);
 	void (*close)(struct vm_area_struct * area);
 	int (*fault)(struct vm_area_struct *vma, struct vm_fault *vmf);
-	struct page *(*nopage)(struct vm_area_struct *area,
-			unsigned long address, int *type);
 	unsigned long (*nopfn)(struct vm_area_struct *area,
 			unsigned long address);
  
@@ -647,12 +645,6 @@
 {
 	return atomic_read(&(page)->_mapcount) >= 0;
 }
-
-/*
- * Error return values for the *_nopage functions
- */
-#define NOPAGE_SIGBUS	(NULL)
-#define NOPAGE_OOM	((struct page *) (-1))
  
 /*
  * Error return values for the *_nopfn functions
@@ -1057,8 +1057,7 @@
 		if (pages)
 			foll_flags |= FOLL_GET;
 		if (!write && !(vma->vm_flags & VM_LOCKED) &&
-		    (!vma->vm_ops || (!vma->vm_ops->nopage &&
-					!vma->vm_ops->fault)))
+		    (!vma->vm_ops || !vma->vm_ops->fault))
 			foll_flags |= FOLL_ANON;
  
 		do {
@@ -2199,20 +2198,9 @@
  
 	BUG_ON(vma->vm_flags & VM_PFNMAP);
  
-	if (likely(vma->vm_ops->fault)) {
-		ret = vma->vm_ops->fault(vma, &vmf);
-		if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))
-			return ret;
-	} else {
-		/* Legacy ->nopage path */
-		ret = 0;
-		vmf.page = vma->vm_ops->nopage(vma, address & PAGE_MASK, &ret);
-		/* no page was available -- either SIGBUS or OOM */
-		if (unlikely(vmf.page == NOPAGE_SIGBUS))
-			return VM_FAULT_SIGBUS;
-		else if (unlikely(vmf.page == NOPAGE_OOM))
-			return VM_FAULT_OOM;
-	}
+	ret = vma->vm_ops->fault(vma, &vmf);
+	if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))
+		return ret;
  
 	/*
 	 * For consistency in subsequent calls, make the faulted page always
@@ -2458,7 +2446,7 @@
 	if (!pte_present(entry)) {
 		if (pte_none(entry)) {
 			if (vma->vm_ops) {
-				if (vma->vm_ops->fault || vma->vm_ops->nopage)
+				if (likely(vma->vm_ops->fault))
 					return do_linear_fault(mm, vma, address,
 						pte, pmd, write_access, entry);
 				if (unlikely(vma->vm_ops->nopfn))
@@ -33,7 +33,7 @@
 	 * When tmpfs swaps out a page from a file, any process mapping that
 	 * file will not get a swp_entry_t in its pte, but rather it is like
 	 * any other file mapping (ie. marked !present and faulted in with
-	 * tmpfs's .nopage). So swapped out tmpfs mappings are tested here.
+	 * tmpfs's .fault). So swapped out tmpfs mappings are tested here.
 	 *
 	 * However when tmpfs moves the page from pagecache and into swapcache,
 	 * it is still in core, but the find_get_page below won't find it.
@@ -662,7 +662,6 @@
 			printk (KERN_EMERG "  page->mapping = %p\n", page->mapping);
 			print_symbol (KERN_EMERG "  vma->vm_ops = %s\n", (unsigned long)vma->vm_ops);
 			if (vma->vm_ops) {
-				print_symbol (KERN_EMERG "  vma->vm_ops->nopage = %s\n", (unsigned long)vma->vm_ops->nopage);
 				print_symbol (KERN_EMERG "  vma->vm_ops->fault = %s\n", (unsigned long)vma->vm_ops->fault);
 			}
 			if (vma->vm_file && vma->vm_file->f_op)
...	...	@@ -128,15 +128,6 @@
128	128
129	129	---------------------------
130	130
131		-What: vm_ops.nopage
132		-When: Soon, provided in-kernel callers have been converted
133		-Why: This interface is replaced by vm_ops.fault, but it has been around
134		- forever, is used by a lot of drivers, and doesn't cost much to
135		- maintain.
136		-Who: Nick Piggin <npiggin@suse.de>
137		-
138		----------------------------
139		-
140	131	What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
141	132	When: October 2008
142	133	Why: The stacking of class devices makes these values misleading and
...	...	@@ -511,7 +511,6 @@
511	511	void (open)(struct vm_area_struct);
512	512	void (close)(struct vm_area_struct);
513	513	int (fault)(struct vm_area_struct, struct vm_fault *);
514		- struct page (nopage)(struct vm_area_struct, unsigned long, int );
515	514	int (page_mkwrite)(struct vm_area_struct , struct page *);
516	515
517	516	locking rules:
...	...	@@ -519,7 +518,6 @@
519	518	open: no yes
520	519	close: no yes
521	520	fault: no yes
522		-nopage: no yes
523	521	page_mkwrite: no yes no
524	522
525	523	->page_mkwrite() is called when a previously read-only page is
...	...	@@ -537,5 +535,4 @@
537	535
538	536	ipc/shm.c::shm_delete() - may need BKL.
539	537	->read() and ->write() in many drivers are (probably) missing BKL.
540		-drivers/sgi/char/graphics.c::sgi_graphics_nopage() - may need BKL.
...	...	@@ -13,7 +13,7 @@
13	13	/*
14	14	* TODO:
15	15	* - remove "mark pages reserved-hacks" from memory allocation code
16		- * and implement nopage()
	16	+ * and implement fault()
17	17	* - check decimation, calculating and reporting image size when
18	18	* using decimation
19	19	* - implement read(), user mode buffers and overlay (?)
...	...	@@ -112,8 +112,9 @@
112	112
113	113	/*
114	114	* It seems like __get_free_pages only ups the usage count
115		- * of the first page. This doesn't work with nopage mapping, so
116		- * up the usage count once more.
	115	+ * of the first page. This doesn't work with fault mapping, so
	116	+ * up the usage count once more (XXX: should use split_page or
	117	+ * compound page).
117	118	*/
118	119
119	120	memset((void *)va->logical, 0x00, va->size);
...	...	@@ -438,7 +438,7 @@
438	438	int error;
439	439
440	440	/*
441		- * Due to the order of unstuffing files and ->nopage(), we can be
	441	+ * Due to the order of unstuffing files and ->fault(), we can be
442	442	* asked for a zero page in the case of a stuffed file being extended,
443	443	* so we need to supply one here. It doesn't happen often.
444	444	*/
...	...	@@ -164,8 +164,6 @@
164	164	void (open)(struct vm_area_struct area);
165	165	void (close)(struct vm_area_struct area);
166	166	int (fault)(struct vm_area_struct vma, struct vm_fault *vmf);
167		- struct page (nopage)(struct vm_area_struct *area,
168		- unsigned long address, int *type);
169	167	unsigned long (nopfn)(struct vm_area_struct area,
170	168	unsigned long address);
171	169
...	...	@@ -647,12 +645,6 @@
647	645	{
648	646	return atomic_read(&(page)->_mapcount) >= 0;
649	647	}
650		-
651		-/*
652		- * Error return values for the *_nopage functions
653		- */
654		-#define NOPAGE_SIGBUS (NULL)
655		-#define NOPAGE_OOM ((struct page *) (-1))
656	648
657	649	/*
658	650	* Error return values for the *_nopfn functions
...	...	@@ -1057,8 +1057,7 @@
1057	1057	if (pages)
1058	1058	foll_flags \|= FOLL_GET;
1059	1059	if (!write && !(vma->vm_flags & VM_LOCKED) &&
1060		- (!vma->vm_ops \|\| (!vma->vm_ops->nopage &&
1061		- !vma->vm_ops->fault)))
	1060	+ (!vma->vm_ops \|\| !vma->vm_ops->fault))
1062	1061	foll_flags \|= FOLL_ANON;
1063	1062
1064	1063	do {
...	...	@@ -2199,20 +2198,9 @@
2199	2198
2200	2199	BUG_ON(vma->vm_flags & VM_PFNMAP);
2201	2200
2202		- if (likely(vma->vm_ops->fault)) {
2203		- ret = vma->vm_ops->fault(vma, &vmf);
2204		- if (unlikely(ret & (VM_FAULT_ERROR \| VM_FAULT_NOPAGE)))
2205		- return ret;
2206		- } else {
2207		- /* Legacy ->nopage path */
2208		- ret = 0;
2209		- vmf.page = vma->vm_ops->nopage(vma, address & PAGE_MASK, &ret);
2210		- /* no page was available -- either SIGBUS or OOM */
2211		- if (unlikely(vmf.page == NOPAGE_SIGBUS))
2212		- return VM_FAULT_SIGBUS;
2213		- else if (unlikely(vmf.page == NOPAGE_OOM))
2214		- return VM_FAULT_OOM;
2215		- }
	2201	+ ret = vma->vm_ops->fault(vma, &vmf);
	2202	+ if (unlikely(ret & (VM_FAULT_ERROR \| VM_FAULT_NOPAGE)))
	2203	+ return ret;
2216	2204
2217	2205	/*
2218	2206	* For consistency in subsequent calls, make the faulted page always
...	...	@@ -2458,7 +2446,7 @@
2458	2446	if (!pte_present(entry)) {
2459	2447	if (pte_none(entry)) {
2460	2448	if (vma->vm_ops) {
2461		- if (vma->vm_ops->fault \|\| vma->vm_ops->nopage)
	2449	+ if (likely(vma->vm_ops->fault))
2462	2450	return do_linear_fault(mm, vma, address,
2463	2451	pte, pmd, write_access, entry);
2464	2452	if (unlikely(vma->vm_ops->nopfn))
...	...	@@ -33,7 +33,7 @@
33	33	* When tmpfs swaps out a page from a file, any process mapping that
34	34	* file will not get a swp_entry_t in its pte, but rather it is like
35	35	* any other file mapping (ie. marked !present and faulted in with
36		- * tmpfs's .nopage). So swapped out tmpfs mappings are tested here.
	36	+ * tmpfs's .fault). So swapped out tmpfs mappings are tested here.
37	37	*
38	38	* However when tmpfs moves the page from pagecache and into swapcache,
39	39	* it is still in core, but the find_get_page below won't find it.
...	...	@@ -662,7 +662,6 @@
662	662	printk (KERN_EMERG " page->mapping = %p\n", page->mapping);
663	663	print_symbol (KERN_EMERG " vma->vm_ops = %s\n", (unsigned long)vma->vm_ops);
664	664	if (vma->vm_ops) {
665		- print_symbol (KERN_EMERG " vma->vm_ops->nopage = %s\n", (unsigned long)vma->vm_ops->nopage);
666	665	print_symbol (KERN_EMERG " vma->vm_ops->fault = %s\n", (unsigned long)vma->vm_ops->fault);
667	666	}
668	667	if (vma->vm_file && vma->vm_file->f_op)