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/drivers/staging/lustre/lustre/osc/lproc_osc.c b/drivers/staging/lustre/lustre/osc/lproc_osc.c
index 57c43c506ef2..a3358c39b2f1 100644
--- a/drivers/staging/lustre/lustre/osc/lproc_osc.c
+++ b/drivers/staging/lustre/lustre/osc/lproc_osc.c
@@ -162,15 +162,15 @@ static ssize_t max_dirty_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 <= 0 ||
-	    pages_number > OSC_MAX_DIRTY_MB_MAX << (20 - PAGE_CACHE_SHIFT) ||
+	    pages_number > OSC_MAX_DIRTY_MB_MAX << (20 - PAGE_SHIFT) ||
 	    pages_number > totalram_pages / 4) /* 1/4 of RAM */
 		return -ERANGE;
 
 	client_obd_list_lock(&cli->cl_loi_list_lock);
-	cli->cl_dirty_max = (u32)(pages_number << PAGE_CACHE_SHIFT);
+	cli->cl_dirty_max = (u32)(pages_number << PAGE_SHIFT);
 	osc_wake_cache_waiters(cli);
 	client_obd_list_unlock(&cli->cl_loi_list_lock);
 
@@ -182,7 +182,7 @@ static int osc_cached_mb_seq_show(struct seq_file *m, void *v)
 {
 	struct obd_device *dev = m->private;
 	struct client_obd *cli = &dev->u.cli;
-	int shift = 20 - PAGE_CACHE_SHIFT;
+	int shift = 20 - PAGE_SHIFT;
 
 	seq_printf(m,
 		   "used_mb: %d\n"
@@ -211,7 +211,7 @@ static ssize_t osc_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, "used_mb:", &count) -
 		  kernbuf;
 	rc = lprocfs_write_frac_helper(buffer, count, &pages_number, mult);
@@ -569,12 +569,12 @@ static ssize_t max_pages_per_rpc_store(struct kobject *kobj,
 
 	/* if the max_pages is specified in bytes, convert to pages */
 	if (val >= ONE_MB_BRW_SIZE)
-		val >>= PAGE_CACHE_SHIFT;
+		val >>= PAGE_SHIFT;
 
-	chunk_mask = ~((1 << (cli->cl_chunkbits - PAGE_CACHE_SHIFT)) - 1);
+	chunk_mask = ~((1 << (cli->cl_chunkbits - PAGE_SHIFT)) - 1);
 	/* max_pages_per_rpc must be chunk aligned */
 	val = (val + ~chunk_mask) & chunk_mask;
-	if (val == 0 || val > ocd->ocd_brw_size >> PAGE_CACHE_SHIFT) {
+	if (val == 0 || val > ocd->ocd_brw_size >> PAGE_SHIFT) {
 		return -ERANGE;
 	}
 	client_obd_list_lock(&cli->cl_loi_list_lock);