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, 11 insertions, 11 deletions

diff --git a/drivers/staging/lustre/lustre/llite/rw.c b/drivers/staging/lustre/lustre/llite/rw.c
index 34614ac..4c7250a 100644
--- a/drivers/staging/lustre/lustre/llite/rw.c
+++ b/drivers/staging/lustre/lustre/llite/rw.c
@@ -146,10 +146,10 @@ static struct ll_cl_context *ll_cl_init(struct file *file,
 		 */
 		io->ci_lockreq = CILR_NEVER;
 
-		pos = vmpage->index << PAGE_CACHE_SHIFT;
+		pos = vmpage->index << PAGE_SHIFT;
 
 		/* Create a temp IO to serve write. */
-		result = cl_io_rw_init(env, io, CIT_WRITE, pos, PAGE_CACHE_SIZE);
+		result = cl_io_rw_init(env, io, CIT_WRITE, pos, PAGE_SIZE);
 		if (result == 0) {
 			cio->cui_fd = LUSTRE_FPRIVATE(file);
 			cio->cui_iter = NULL;
@@ -498,7 +498,7 @@ static int ll_read_ahead_page(const struct lu_env *env, struct cl_io *io,
 		}
 		if (rc != 1)
 			unlock_page(vmpage);
-		page_cache_release(vmpage);
+		put_page(vmpage);
 	} else {
 		which = RA_STAT_FAILED_GRAB_PAGE;
 		msg   = "g_c_p_n failed";
@@ -527,7 +527,7 @@ static int ll_read_ahead_page(const struct lu_env *env, struct cl_io *io,
  * and max_read_ahead_per_file_mb otherwise the readahead budget can be used
  * up quickly which will affect read performance significantly. See LU-2816
  */
-#define RAS_INCREASE_STEP(inode) (ONE_MB_BRW_SIZE >> PAGE_CACHE_SHIFT)
+#define RAS_INCREASE_STEP(inode) (ONE_MB_BRW_SIZE >> PAGE_SHIFT)
 
 static inline int stride_io_mode(struct ll_readahead_state *ras)
 {
@@ -739,7 +739,7 @@ int ll_readahead(const struct lu_env *env, struct cl_io *io,
 			end = rpc_boundary;
 
 		/* Truncate RA window to end of file */
-		end = min(end, (unsigned long)((kms - 1) >> PAGE_CACHE_SHIFT));
+		end = min(end, (unsigned long)((kms - 1) >> PAGE_SHIFT));
 
 		ras->ras_next_readahead = max(end, end + 1);
 		RAS_CDEBUG(ras);
@@ -776,7 +776,7 @@ int ll_readahead(const struct lu_env *env, struct cl_io *io,
 	if (reserved != 0)
 		ll_ra_count_put(ll_i2sbi(inode), reserved);
 
-	if (ra_end == end + 1 && ra_end == (kms >> PAGE_CACHE_SHIFT))
+	if (ra_end == end + 1 && ra_end == (kms >> PAGE_SHIFT))
 		ll_ra_stats_inc(mapping, RA_STAT_EOF);
 
 	/* if we didn't get to the end of the region we reserved from
@@ -985,8 +985,8 @@ void ras_update(struct ll_sb_info *sbi, struct inode *inode,
 	if (ras->ras_requests == 2 && !ras->ras_request_index) {
 		__u64 kms_pages;
 
-		kms_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
-			    PAGE_CACHE_SHIFT;
+		kms_pages = (i_size_read(inode) + PAGE_SIZE - 1) >>
+			    PAGE_SHIFT;
 
 		CDEBUG(D_READA, "kmsp %llu mwp %lu mp %lu\n", kms_pages,
 		       ra->ra_max_read_ahead_whole_pages, ra->ra_max_pages_per_file);
@@ -1173,7 +1173,7 @@ int ll_writepage(struct page *vmpage, struct writeback_control *wbc)
 		 * PageWriteback or clean the page.
 		 */
 		result = cl_sync_file_range(inode, offset,
-					    offset + PAGE_CACHE_SIZE - 1,
+					    offset + PAGE_SIZE - 1,
 					    CL_FSYNC_LOCAL, 1);
 		if (result > 0) {
 			/* actually we may have written more than one page.
@@ -1211,7 +1211,7 @@ int ll_writepages(struct address_space *mapping, struct writeback_control *wbc)
 	int ignore_layout = 0;
 
 	if (wbc->range_cyclic) {
-		start = mapping->writeback_index << PAGE_CACHE_SHIFT;
+		start = mapping->writeback_index << PAGE_SHIFT;
 		end = OBD_OBJECT_EOF;
 	} else {
 		start = wbc->range_start;
@@ -1241,7 +1241,7 @@ int ll_writepages(struct address_space *mapping, struct writeback_control *wbc)
 	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) {
 		if (end == OBD_OBJECT_EOF)
 			end = i_size_read(inode);
-		mapping->writeback_index = (end >> PAGE_CACHE_SHIFT) + 1;
+		mapping->writeback_index = (end >> PAGE_SHIFT) + 1;
 	}
 	return result;
 }