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, 9 insertions, 9 deletions

diff --git a/drivers/staging/lustre/lustre/llite/lproc_llite.c b/drivers/staging/lustre/lustre/llite/lproc_llite.c
index 45941a6600fe..27ab1261400e 100644
--- a/drivers/staging/lustre/lustre/llite/lproc_llite.c
+++ b/drivers/staging/lustre/lustre/llite/lproc_llite.c
@@ -233,7 +233,7 @@ static ssize_t max_read_ahead_mb_show(struct kobject *kobj,
 	pages_number = sbi->ll_ra_info.ra_max_pages;
 	spin_unlock(&sbi->ll_lock);
 
-	mult = 1 << (20 - PAGE_CACHE_SHIFT);
+	mult = 1 << (20 - PAGE_SHIFT);
 	return lprocfs_read_frac_helper(buf, PAGE_SIZE, pages_number, mult);
 }
 
@@ -251,12 +251,12 @@ static ssize_t max_read_ahead_mb_store(struct kobject *kobj,
 	if (rc)
 		return rc;
 
-	pages_number *= 1 << (20 - PAGE_CACHE_SHIFT); /* MB -> pages */
+	pages_number *= 1 << (20 - PAGE_SHIFT); /* MB -> pages */
 
 	if (pages_number > totalram_pages / 2) {
 
 		CERROR("can't set file readahead more than %lu MB\n",
-		       totalram_pages >> (20 - PAGE_CACHE_SHIFT + 1)); /*1/2 of RAM*/
+		       totalram_pages >> (20 - PAGE_SHIFT + 1)); /*1/2 of RAM*/
 		return -ERANGE;
 	}
 
@@ -281,7 +281,7 @@ static ssize_t max_read_ahead_per_file_mb_show(struct kobject *kobj,
 	pages_number = sbi->ll_ra_info.ra_max_pages_per_file;
 	spin_unlock(&sbi->ll_lock);
 
-	mult = 1 << (20 - PAGE_CACHE_SHIFT);
+	mult = 1 << (20 - PAGE_SHIFT);
 	return lprocfs_read_frac_helper(buf, PAGE_SIZE, pages_number, mult);
 }
 
@@ -326,7 +326,7 @@ static ssize_t max_read_ahead_whole_mb_show(struct kobject *kobj,
 	pages_number = sbi->ll_ra_info.ra_max_read_ahead_whole_pages;
 	spin_unlock(&sbi->ll_lock);
 
-	mult = 1 << (20 - PAGE_CACHE_SHIFT);
+	mult = 1 << (20 - PAGE_SHIFT);
 	return lprocfs_read_frac_helper(buf, PAGE_SIZE, pages_number, mult);
 }
 
@@ -349,7 +349,7 @@ static ssize_t max_read_ahead_whole_mb_store(struct kobject *kobj,
 	 */
 	if (pages_number > sbi->ll_ra_info.ra_max_pages_per_file) {
 		CERROR("can't set max_read_ahead_whole_mb more than max_read_ahead_per_file_mb: %lu\n",
-		       sbi->ll_ra_info.ra_max_pages_per_file >> (20 - PAGE_CACHE_SHIFT));
+		       sbi->ll_ra_info.ra_max_pages_per_file >> (20 - PAGE_SHIFT));
 		return -ERANGE;
 	}
 
@@ -366,7 +366,7 @@ static int ll_max_cached_mb_seq_show(struct seq_file *m, void *v)
 	struct super_block     *sb    = m->private;
 	struct ll_sb_info      *sbi   = ll_s2sbi(sb);
 	struct cl_client_cache *cache = &sbi->ll_cache;
-	int shift = 20 - PAGE_CACHE_SHIFT;
+	int shift = 20 - PAGE_SHIFT;
 	int max_cached_mb;
 	int unused_mb;
 
@@ -405,7 +405,7 @@ static ssize_t ll_max_cached_mb_seq_write(struct file *file,
 		return -EFAULT;
 	kernbuf[count] = 0;
 
-	mult = 1 << (20 - PAGE_CACHE_SHIFT);
+	mult = 1 << (20 - PAGE_SHIFT);
 	buffer += lprocfs_find_named_value(kernbuf, "max_cached_mb:", &count) -
 		  kernbuf;
 	rc = lprocfs_write_frac_helper(buffer, count, &pages_number, mult);
@@ -415,7 +415,7 @@ static ssize_t ll_max_cached_mb_seq_write(struct file *file,
 	if (pages_number < 0 || pages_number > totalram_pages) {
 		CERROR("%s: can't set max cache more than %lu MB\n",
 		       ll_get_fsname(sb, NULL, 0),
-		       totalram_pages >> (20 - PAGE_CACHE_SHIFT));
+		       totalram_pages >> (20 - PAGE_SHIFT));
 		return -ERANGE;
 	}