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>

3 files changed, 12 insertions, 12 deletions

diff --git a/drivers/staging/lustre/lnet/libcfs/debug.c b/drivers/staging/lustre/lnet/libcfs/debug.c
index c90e510..c3d628b 100644
--- a/drivers/staging/lustre/lnet/libcfs/debug.c
+++ b/drivers/staging/lustre/lnet/libcfs/debug.c
@@ -517,7 +517,7 @@ int libcfs_debug_init(unsigned long bufsize)
 		max = TCD_MAX_PAGES;
 	} else {
 		max = max / num_possible_cpus();
-		max <<= (20 - PAGE_CACHE_SHIFT);
+		max <<= (20 - PAGE_SHIFT);
 	}
 	rc = cfs_tracefile_init(max);
 
diff --git a/drivers/staging/lustre/lnet/libcfs/tracefile.c b/drivers/staging/lustre/lnet/libcfs/tracefile.c
index ec3bc04..244eb89 100644
--- a/drivers/staging/lustre/lnet/libcfs/tracefile.c
+++ b/drivers/staging/lustre/lnet/libcfs/tracefile.c
@@ -182,7 +182,7 @@ cfs_trace_get_tage_try(struct cfs_trace_cpu_data *tcd, unsigned long len)
 	if (tcd->tcd_cur_pages > 0) {
 		__LASSERT(!list_empty(&tcd->tcd_pages));
 		tage = cfs_tage_from_list(tcd->tcd_pages.prev);
-		if (tage->used + len <= PAGE_CACHE_SIZE)
+		if (tage->used + len <= PAGE_SIZE)
 			return tage;
 	}
 
@@ -260,7 +260,7 @@ static struct cfs_trace_page *cfs_trace_get_tage(struct cfs_trace_cpu_data *tcd,
 	 * from here: this will lead to infinite recursion.
 	 */
 
-	if (len > PAGE_CACHE_SIZE) {
+	if (len > PAGE_SIZE) {
 		pr_err("cowardly refusing to write %lu bytes in a page\n", len);
 		return NULL;
 	}
@@ -349,7 +349,7 @@ int libcfs_debug_vmsg2(struct libcfs_debug_msg_data *msgdata,
 	for (i = 0; i < 2; i++) {
 		tage = cfs_trace_get_tage(tcd, needed + known_size + 1);
 		if (!tage) {
-			if (needed + known_size > PAGE_CACHE_SIZE)
+			if (needed + known_size > PAGE_SIZE)
 				mask |= D_ERROR;
 
 			cfs_trace_put_tcd(tcd);
@@ -360,7 +360,7 @@ int libcfs_debug_vmsg2(struct libcfs_debug_msg_data *msgdata,
 		string_buf = (char *)page_address(tage->page) +
 					tage->used + known_size;
 
-		max_nob = PAGE_CACHE_SIZE - tage->used - known_size;
+		max_nob = PAGE_SIZE - tage->used - known_size;
 		if (max_nob <= 0) {
 			printk(KERN_EMERG "negative max_nob: %d\n",
 			       max_nob);
@@ -424,7 +424,7 @@ int libcfs_debug_vmsg2(struct libcfs_debug_msg_data *msgdata,
 	__LASSERT(debug_buf == string_buf);
 
 	tage->used += needed;
-	__LASSERT(tage->used <= PAGE_CACHE_SIZE);
+	__LASSERT(tage->used <= PAGE_SIZE);
 
 console:
 	if ((mask & libcfs_printk) == 0) {
@@ -835,7 +835,7 @@ EXPORT_SYMBOL(cfs_trace_copyout_string);
 
 int cfs_trace_allocate_string_buffer(char **str, int nob)
 {
-	if (nob > 2 * PAGE_CACHE_SIZE)	    /* string must be "sensible" */
+	if (nob > 2 * PAGE_SIZE)	    /* string must be "sensible" */
 		return -EINVAL;
 
 	*str = kmalloc(nob, GFP_KERNEL | __GFP_ZERO);
@@ -951,7 +951,7 @@ int cfs_trace_set_debug_mb(int mb)
 	}
 
 	mb /= num_possible_cpus();
-	pages = mb << (20 - PAGE_CACHE_SHIFT);
+	pages = mb << (20 - PAGE_SHIFT);
 
 	cfs_tracefile_write_lock();
 
@@ -977,7 +977,7 @@ int cfs_trace_get_debug_mb(void)
 
 	cfs_tracefile_read_unlock();
 
-	return (total_pages >> (20 - PAGE_CACHE_SHIFT)) + 1;
+	return (total_pages >> (20 - PAGE_SHIFT)) + 1;
 }
 
 static int tracefiled(void *arg)
diff --git a/drivers/staging/lustre/lnet/libcfs/tracefile.h b/drivers/staging/lustre/lnet/libcfs/tracefile.h
index 4c77f90..ac84e7f 100644
--- a/drivers/staging/lustre/lnet/libcfs/tracefile.h
+++ b/drivers/staging/lustre/lnet/libcfs/tracefile.h
@@ -87,7 +87,7 @@ void libcfs_unregister_panic_notifier(void);
 extern int  libcfs_panic_in_progress;
 int cfs_trace_max_debug_mb(void);
 
-#define TCD_MAX_PAGES (5 << (20 - PAGE_CACHE_SHIFT))
+#define TCD_MAX_PAGES (5 << (20 - PAGE_SHIFT))
 #define TCD_STOCK_PAGES (TCD_MAX_PAGES)
 #define CFS_TRACEFILE_SIZE (500 << 20)
 
@@ -96,7 +96,7 @@ int cfs_trace_max_debug_mb(void);
 /*
  * Private declare for tracefile
  */
-#define TCD_MAX_PAGES (5 << (20 - PAGE_CACHE_SHIFT))
+#define TCD_MAX_PAGES (5 << (20 - PAGE_SHIFT))
 #define TCD_STOCK_PAGES (TCD_MAX_PAGES)
 
 #define CFS_TRACEFILE_SIZE (500 << 20)
@@ -257,7 +257,7 @@ do {								    \
 do {								    \
 	__LASSERT(tage);					\
 	__LASSERT(tage->page);				  \
-	__LASSERT(tage->used <= PAGE_CACHE_SIZE);			 \
+	__LASSERT(tage->used <= PAGE_SIZE);			 \
 	__LASSERT(page_count(tage->page) > 0);		      \
 } while (0)