mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 27 insertions, 27 deletions

diff --git a/mm/memory.c b/mm/memory.c
index 098f00d05461..07a420488cda 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2054,7 +2054,7 @@ static inline int wp_page_reuse(struct mm_struct *mm,
 		VM_BUG_ON_PAGE(PageAnon(page), page);
 		mapping = page->mapping;
 		unlock_page(page);
-		page_cache_release(page);
+		put_page(page);
 
 		if ((dirtied || page_mkwrite) && mapping) {
 			/*
@@ -2188,7 +2188,7 @@ static int wp_page_copy(struct mm_struct *mm, struct vm_area_struct *vma,
 	}
 
 	if (new_page)
-		page_cache_release(new_page);
+		put_page(new_page);
 
 	pte_unmap_unlock(page_table, ptl);
 	mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
@@ -2203,14 +2203,14 @@ static int wp_page_copy(struct mm_struct *mm, struct vm_area_struct *vma,
 				munlock_vma_page(old_page);
 			unlock_page(old_page);
 		}
-		page_cache_release(old_page);
+		put_page(old_page);
 	}
 	return page_copied ? VM_FAULT_WRITE : 0;
 oom_free_new:
-	page_cache_release(new_page);
+	put_page(new_page);
 oom:
 	if (old_page)
-		page_cache_release(old_page);
+		put_page(old_page);
 	return VM_FAULT_OOM;
 }
 
@@ -2258,7 +2258,7 @@ static int wp_page_shared(struct mm_struct *mm, struct vm_area_struct *vma,
 {
 	int page_mkwrite = 0;
 
-	page_cache_get(old_page);
+	get_page(old_page);
 
 	if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
 		int tmp;
@@ -2267,7 +2267,7 @@ static int wp_page_shared(struct mm_struct *mm, struct vm_area_struct *vma,
 		tmp = do_page_mkwrite(vma, old_page, address);
 		if (unlikely(!tmp || (tmp &
 				      (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
-			page_cache_release(old_page);
+			put_page(old_page);
 			return tmp;
 		}
 		/*
@@ -2281,7 +2281,7 @@ static int wp_page_shared(struct mm_struct *mm, struct vm_area_struct *vma,
 		if (!pte_same(*page_table, orig_pte)) {
 			unlock_page(old_page);
 			pte_unmap_unlock(page_table, ptl);
-			page_cache_release(old_page);
+			put_page(old_page);
 			return 0;
 		}
 		page_mkwrite = 1;
@@ -2341,7 +2341,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	 */
 	if (PageAnon(old_page) && !PageKsm(old_page)) {
 		if (!trylock_page(old_page)) {
-			page_cache_get(old_page);
+			get_page(old_page);
 			pte_unmap_unlock(page_table, ptl);
 			lock_page(old_page);
 			page_table = pte_offset_map_lock(mm, pmd, address,
@@ -2349,10 +2349,10 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
 			if (!pte_same(*page_table, orig_pte)) {
 				unlock_page(old_page);
 				pte_unmap_unlock(page_table, ptl);
-				page_cache_release(old_page);
+				put_page(old_page);
 				return 0;
 			}
-			page_cache_release(old_page);
+			put_page(old_page);
 		}
 		if (reuse_swap_page(old_page)) {
 			/*
@@ -2375,7 +2375,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	/*
 	 * Ok, we need to copy. Oh, well..
 	 */
-	page_cache_get(old_page);
+	get_page(old_page);
 
 	pte_unmap_unlock(page_table, ptl);
 	return wp_page_copy(mm, vma, address, page_table, pmd,
@@ -2619,7 +2619,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
 		 * parallel locked swapcache.
 		 */
 		unlock_page(swapcache);
-		page_cache_release(swapcache);
+		put_page(swapcache);
 	}
 
 	if (flags & FAULT_FLAG_WRITE) {
@@ -2641,10 +2641,10 @@ out_nomap:
 out_page:
 	unlock_page(page);
 out_release:
-	page_cache_release(page);
+	put_page(page);
 	if (page != swapcache) {
 		unlock_page(swapcache);
-		page_cache_release(swapcache);
+		put_page(swapcache);
 	}
 	return ret;
 }
@@ -2752,7 +2752,7 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	if (userfaultfd_missing(vma)) {
 		pte_unmap_unlock(page_table, ptl);
 		mem_cgroup_cancel_charge(page, memcg, false);
-		page_cache_release(page);
+		put_page(page);
 		return handle_userfault(vma, address, flags,
 					VM_UFFD_MISSING);
 	}
@@ -2771,10 +2771,10 @@ unlock:
 	return 0;
 release:
 	mem_cgroup_cancel_charge(page, memcg, false);
-	page_cache_release(page);
+	put_page(page);
 	goto unlock;
 oom_free_page:
-	page_cache_release(page);
+	put_page(page);
 oom:
 	return VM_FAULT_OOM;
 }
@@ -2807,7 +2807,7 @@ static int __do_fault(struct vm_area_struct *vma, unsigned long address,
 	if (unlikely(PageHWPoison(vmf.page))) {
 		if (ret & VM_FAULT_LOCKED)
 			unlock_page(vmf.page);
-		page_cache_release(vmf.page);
+		put_page(vmf.page);
 		return VM_FAULT_HWPOISON;
 	}
 
@@ -2996,7 +2996,7 @@ static int do_read_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	if (unlikely(!pte_same(*pte, orig_pte))) {
 		pte_unmap_unlock(pte, ptl);
 		unlock_page(fault_page);
-		page_cache_release(fault_page);
+		put_page(fault_page);
 		return ret;
 	}
 	do_set_pte(vma, address, fault_page, pte, false, false);
@@ -3024,7 +3024,7 @@ static int do_cow_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 		return VM_FAULT_OOM;
 
 	if (mem_cgroup_try_charge(new_page, mm, GFP_KERNEL, &memcg, false)) {
-		page_cache_release(new_page);
+		put_page(new_page);
 		return VM_FAULT_OOM;
 	}
 
@@ -3041,7 +3041,7 @@ static int do_cow_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 		pte_unmap_unlock(pte, ptl);
 		if (fault_page) {
 			unlock_page(fault_page);
-			page_cache_release(fault_page);
+			put_page(fault_page);
 		} else {
 			/*
 			 * The fault handler has no page to lock, so it holds
@@ -3057,7 +3057,7 @@ static int do_cow_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	pte_unmap_unlock(pte, ptl);
 	if (fault_page) {
 		unlock_page(fault_page);
-		page_cache_release(fault_page);
+		put_page(fault_page);
 	} else {
 		/*
 		 * The fault handler has no page to lock, so it holds
@@ -3068,7 +3068,7 @@ static int do_cow_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	return ret;
 uncharge_out:
 	mem_cgroup_cancel_charge(new_page, memcg, false);
-	page_cache_release(new_page);
+	put_page(new_page);
 	return ret;
 }
 
@@ -3096,7 +3096,7 @@ static int do_shared_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 		tmp = do_page_mkwrite(vma, fault_page, address);
 		if (unlikely(!tmp ||
 				(tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
-			page_cache_release(fault_page);
+			put_page(fault_page);
 			return tmp;
 		}
 	}
@@ -3105,7 +3105,7 @@ static int do_shared_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	if (unlikely(!pte_same(*pte, orig_pte))) {
 		pte_unmap_unlock(pte, ptl);
 		unlock_page(fault_page);
-		page_cache_release(fault_page);
+		put_page(fault_page);
 		return ret;
 	}
 	do_set_pte(vma, address, fault_page, pte, true, false);
@@ -3736,7 +3736,7 @@ static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
 						    buf, maddr + offset, bytes);
 			}
 			kunmap(page);
-			page_cache_release(page);
+			put_page(page);
 		}
 		len -= bytes;
 		buf += bytes;