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>

2 files changed, 11 insertions, 11 deletions

diff --git a/fs/sysv/dir.c b/fs/sysv/dir.c
index 63c1bcb224ee..c0f0a3e643eb 100644
--- a/fs/sysv/dir.c
+++ b/fs/sysv/dir.c
@@ -30,7 +30,7 @@ const struct file_operations sysv_dir_operations = {
 static inline void dir_put_page(struct page *page)
 {
         kunmap(page);
-        page_cache_release(page);
+        put_page(page);
 }
 
 static int dir_commit_chunk(struct page *page, loff_t pos, unsigned len)
@@ -73,8 +73,8 @@ static int sysv_readdir(struct file *file, struct dir_context *ctx)
         if (pos >= inode->i_size)
                 return 0;
 
-        offset = pos & ~PAGE_CACHE_MASK;
-        n = pos >> PAGE_CACHE_SHIFT;
+        offset = pos & ~PAGE_MASK;
+        n = pos >> PAGE_SHIFT;
 
         for ( ; n < npages; n++, offset = 0) {
                 char *kaddr, *limit;
@@ -85,7 +85,7 @@ static int sysv_readdir(struct file *file, struct dir_context *ctx)
                         continue;
                 kaddr = (char *)page_address(page);
                 de = (struct sysv_dir_entry *)(kaddr+offset);
-                limit = kaddr + PAGE_CACHE_SIZE - SYSV_DIRSIZE;
+                limit = kaddr + PAGE_SIZE - SYSV_DIRSIZE;
                 for ( ;(char*)de <= limit; de++, ctx->pos += sizeof(*de)) {
                         char *name = de->name;
 
@@ -146,7 +146,7 @@ struct sysv_dir_entry *sysv_find_entry(struct dentry *dentry, struct page **res_
                 if (!IS_ERR(page)) {
                         kaddr = (char*)page_address(page);
                         de = (struct sysv_dir_entry *) kaddr;
-                        kaddr += PAGE_CACHE_SIZE - SYSV_DIRSIZE;
+                        kaddr += PAGE_SIZE - SYSV_DIRSIZE;
                         for ( ; (char *) de <= kaddr ; de++) {
                                 if (!de->inode)
                                         continue;
@@ -190,7 +190,7 @@ int sysv_add_link(struct dentry *dentry, struct inode *inode)
                         goto out;
                 kaddr = (char*)page_address(page);
                 de = (struct sysv_dir_entry *)kaddr;
-                kaddr += PAGE_CACHE_SIZE - SYSV_DIRSIZE;
+                kaddr += PAGE_SIZE - SYSV_DIRSIZE;
                 while ((char *)de <= kaddr) {
                         if (!de->inode)
                                 goto got_it;
@@ -261,7 +261,7 @@ int sysv_make_empty(struct inode *inode, struct inode *dir)
         kmap(page);
 
         base = (char*)page_address(page);
-        memset(base, 0, PAGE_CACHE_SIZE);
+        memset(base, 0, PAGE_SIZE);
 
         de = (struct sysv_dir_entry *) base;
         de->inode = cpu_to_fs16(SYSV_SB(inode->i_sb), inode->i_ino);
@@ -273,7 +273,7 @@ int sysv_make_empty(struct inode *inode, struct inode *dir)
         kunmap(page);
         err = dir_commit_chunk(page, 0, 2 * SYSV_DIRSIZE);
 fail:
-        page_cache_release(page);
+        put_page(page);
         return err;
 }
 
@@ -296,7 +296,7 @@ int sysv_empty_dir(struct inode * inode)
 
                 kaddr = (char *)page_address(page);
                 de = (struct sysv_dir_entry *)kaddr;
-                kaddr += PAGE_CACHE_SIZE-SYSV_DIRSIZE;
+                kaddr += PAGE_SIZE-SYSV_DIRSIZE;
 
                 for ( ;(char *)de <= kaddr; de++) {
                         if (!de->inode)
diff --git a/fs/sysv/namei.c b/fs/sysv/namei.c
index 11e83ed0b4bf..90b60c03b588 100644
--- a/fs/sysv/namei.c
+++ b/fs/sysv/namei.c
@@ -264,11 +264,11 @@ static int sysv_rename(struct inode * old_dir, struct dentry * old_dentry,
 out_dir:
         if (dir_de) {
                 kunmap(dir_page);
-                page_cache_release(dir_page);
+                put_page(dir_page);
         }
 out_old:
         kunmap(old_page);
-        page_cache_release(old_page);
+        put_page(old_page);
 out:
         return err;
 }