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, 8 insertions, 8 deletions

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index c9384f932975..208efc70ad49 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -354,8 +354,8 @@ static int gfs2_allocate_page_backing(struct page *page)
 {
         struct inode *inode = page->mapping->host;
         struct buffer_head bh;
-        unsigned long size = PAGE_CACHE_SIZE;
-        u64 lblock = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
+        unsigned long size = PAGE_SIZE;
+        u64 lblock = page->index << (PAGE_SHIFT - inode->i_blkbits);
 
         do {
                 bh.b_state = 0;
@@ -386,7 +386,7 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
         struct gfs2_sbd *sdp = GFS2_SB(inode);
         struct gfs2_alloc_parms ap = { .aflags = 0, };
         unsigned long last_index;
-        u64 pos = page->index << PAGE_CACHE_SHIFT;
+        u64 pos = page->index << PAGE_SHIFT;
         unsigned int data_blocks, ind_blocks, rblocks;
         struct gfs2_holder gh;
         loff_t size;
@@ -401,7 +401,7 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
         if (ret)
                 goto out;
 
-        gfs2_size_hint(vma->vm_file, pos, PAGE_CACHE_SIZE);
+        gfs2_size_hint(vma->vm_file, pos, PAGE_SIZE);
 
         gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
         ret = gfs2_glock_nq(&gh);
@@ -411,7 +411,7 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
         set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
         set_bit(GIF_SW_PAGED, &ip->i_flags);
 
-        if (!gfs2_write_alloc_required(ip, pos, PAGE_CACHE_SIZE)) {
+        if (!gfs2_write_alloc_required(ip, pos, PAGE_SIZE)) {
                 lock_page(page);
                 if (!PageUptodate(page) || page->mapping != inode->i_mapping) {
                         ret = -EAGAIN;
@@ -424,7 +424,7 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
         if (ret)
                 goto out_unlock;
 
-        gfs2_write_calc_reserv(ip, PAGE_CACHE_SIZE, &data_blocks, &ind_blocks);
+        gfs2_write_calc_reserv(ip, PAGE_SIZE, &data_blocks, &ind_blocks);
         ap.target = data_blocks + ind_blocks;
         ret = gfs2_quota_lock_check(ip, &ap);
         if (ret)
@@ -447,7 +447,7 @@ static int gfs2_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
         lock_page(page);
         ret = -EINVAL;
         size = i_size_read(inode);
-        last_index = (size - 1) >> PAGE_CACHE_SHIFT;
+        last_index = (size - 1) >> PAGE_SHIFT;
         /* Check page index against inode size */
         if (size == 0 || (page->index > last_index))
                 goto out_trans_end;
@@ -873,7 +873,7 @@ static long __gfs2_fallocate(struct file *file, int mode, loff_t offset, loff_t
                         rblocks += data_blocks ? data_blocks : 1;
 
                 error = gfs2_trans_begin(sdp, rblocks,
-                                         PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize);
+                                         PAGE_SIZE/sdp->sd_sb.sb_bsize);
                 if (error)
                         goto out_trans_fail;