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, 13 insertions, 13 deletions

diff --git a/fs/afs/write.c b/fs/afs/write.c
index dfef94f70667..65de439bdc4f 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -93,10 +93,10 @@ static int afs_fill_page(struct afs_vnode *vnode, struct key *key,
         _enter(",,%llu", (unsigned long long)pos);
 
         i_size = i_size_read(&vnode->vfs_inode);
-        if (pos + PAGE_CACHE_SIZE > i_size)
+        if (pos + PAGE_SIZE > i_size)
                 len = i_size - pos;
         else
-                len = PAGE_CACHE_SIZE;
+                len = PAGE_SIZE;
 
         ret = afs_vnode_fetch_data(vnode, key, pos, len, page);
         if (ret < 0) {
@@ -123,9 +123,9 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
         struct afs_vnode *vnode = AFS_FS_I(file_inode(file));
         struct page *page;
         struct key *key = file->private_data;
-        unsigned from = pos & (PAGE_CACHE_SIZE - 1);
+        unsigned from = pos & (PAGE_SIZE - 1);
         unsigned to = from + len;
-        pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+        pgoff_t index = pos >> PAGE_SHIFT;
         int ret;
 
         _enter("{%x:%u},{%lx},%u,%u",
@@ -151,8 +151,8 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
         *pagep = page;
         /* page won't leak in error case: it eventually gets cleaned off LRU */
 
-        if (!PageUptodate(page) && len != PAGE_CACHE_SIZE) {
-                ret = afs_fill_page(vnode, key, index << PAGE_CACHE_SHIFT, page);
+        if (!PageUptodate(page) && len != PAGE_SIZE) {
+                ret = afs_fill_page(vnode, key, index << PAGE_SHIFT, page);
                 if (ret < 0) {
                         kfree(candidate);
                         _leave(" = %d [prep]", ret);
@@ -266,7 +266,7 @@ int afs_write_end(struct file *file, struct address_space *mapping,
         if (PageDirty(page))
                 _debug("dirtied");
         unlock_page(page);
-        page_cache_release(page);
+        put_page(page);
 
         return copied;
 }
@@ -480,7 +480,7 @@ static int afs_writepages_region(struct address_space *mapping,
 
                 if (page->index > end) {
                         *_next = index;
-                        page_cache_release(page);
+                        put_page(page);
                         _leave(" = 0 [%lx]", *_next);
                         return 0;
                 }
@@ -494,7 +494,7 @@ static int afs_writepages_region(struct address_space *mapping,
 
                 if (page->mapping != mapping) {
                         unlock_page(page);
-                        page_cache_release(page);
+                        put_page(page);
                         continue;
                 }
 
@@ -515,7 +515,7 @@ static int afs_writepages_region(struct address_space *mapping,
 
                 ret = afs_write_back_from_locked_page(wb, page);
                 unlock_page(page);
-                page_cache_release(page);
+                put_page(page);
                 if (ret < 0) {
                         _leave(" = %d", ret);
                         return ret;
@@ -551,13 +551,13 @@ int afs_writepages(struct address_space *mapping,
                                                     &next);
                 mapping->writeback_index = next;
         } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) {
-                end = (pgoff_t)(LLONG_MAX >> PAGE_CACHE_SHIFT);
+                end = (pgoff_t)(LLONG_MAX >> PAGE_SHIFT);
                 ret = afs_writepages_region(mapping, wbc, 0, end, &next);
                 if (wbc->nr_to_write > 0)
                         mapping->writeback_index = next;
         } else {
-                start = wbc->range_start >> PAGE_CACHE_SHIFT;
-                end = wbc->range_end >> PAGE_CACHE_SHIFT;
+                start = wbc->range_start >> PAGE_SHIFT;
+                end = wbc->range_end >> PAGE_SHIFT;
                 ret = afs_writepages_region(mapping, wbc, start, end, &next);
         }