[PATCH 45/71] jfs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

From: Kirill A. Shutemov
Date: Sun Mar 20 2016 - 14:57:12 EST


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>;

- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

- page_cache_get() -> get_page();

- page_cache_release() -> put_page();

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Dave Kleikamp <shaggy@xxxxxxxxxx>
---
fs/jfs/jfs_metapage.c | 42 +++++++++++++++++++++---------------------
fs/jfs/jfs_metapage.h | 4 ++--
fs/jfs/super.c | 2 +-
3 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/fs/jfs/jfs_metapage.c b/fs/jfs/jfs_metapage.c
index a3eb316b1ac3..b60e015cc757 100644
--- a/fs/jfs/jfs_metapage.c
+++ b/fs/jfs/jfs_metapage.c
@@ -80,7 +80,7 @@ static inline void lock_metapage(struct metapage *mp)
static struct kmem_cache *metapage_cache;
static mempool_t *metapage_mempool;

-#define MPS_PER_PAGE (PAGE_CACHE_SIZE >> L2PSIZE)
+#define MPS_PER_PAGE (PAGE_SIZE >> L2PSIZE)

#if MPS_PER_PAGE > 1

@@ -316,7 +316,7 @@ static void last_write_complete(struct page *page)
struct metapage *mp;
unsigned int offset;

- for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
+ for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
mp = page_to_mp(page, offset);
if (mp && test_bit(META_io, &mp->flag)) {
if (mp->lsn)
@@ -366,12 +366,12 @@ static int metapage_writepage(struct page *page, struct writeback_control *wbc)
int bad_blocks = 0;

page_start = (sector_t)page->index <<
- (PAGE_CACHE_SHIFT - inode->i_blkbits);
+ (PAGE_SHIFT - inode->i_blkbits);
BUG_ON(!PageLocked(page));
BUG_ON(PageWriteback(page));
set_page_writeback(page);

- for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
+ for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
mp = page_to_mp(page, offset);

if (!mp || !test_bit(META_dirty, &mp->flag))
@@ -416,7 +416,7 @@ static int metapage_writepage(struct page *page, struct writeback_control *wbc)
bio = NULL;
} else
inc_io(page);
- xlen = (PAGE_CACHE_SIZE - offset) >> inode->i_blkbits;
+ xlen = (PAGE_SIZE - offset) >> inode->i_blkbits;
pblock = metapage_get_blocks(inode, lblock, &xlen);
if (!pblock) {
printk(KERN_ERR "JFS: metapage_get_blocks failed\n");
@@ -485,7 +485,7 @@ static int metapage_readpage(struct file *fp, struct page *page)
struct inode *inode = page->mapping->host;
struct bio *bio = NULL;
int block_offset;
- int blocks_per_page = PAGE_CACHE_SIZE >> inode->i_blkbits;
+ int blocks_per_page = PAGE_SIZE >> inode->i_blkbits;
sector_t page_start; /* address of page in fs blocks */
sector_t pblock;
int xlen;
@@ -494,7 +494,7 @@ static int metapage_readpage(struct file *fp, struct page *page)

BUG_ON(!PageLocked(page));
page_start = (sector_t)page->index <<
- (PAGE_CACHE_SHIFT - inode->i_blkbits);
+ (PAGE_SHIFT - inode->i_blkbits);

block_offset = 0;
while (block_offset < blocks_per_page) {
@@ -542,7 +542,7 @@ static int metapage_releasepage(struct page *page, gfp_t gfp_mask)
int ret = 1;
int offset;

- for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
+ for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
mp = page_to_mp(page, offset);

if (!mp)
@@ -568,7 +568,7 @@ static int metapage_releasepage(struct page *page, gfp_t gfp_mask)
static void metapage_invalidatepage(struct page *page, unsigned int offset,
unsigned int length)
{
- BUG_ON(offset || length < PAGE_CACHE_SIZE);
+ BUG_ON(offset || length < PAGE_SIZE);

BUG_ON(PageWriteback(page));

@@ -599,10 +599,10 @@ struct metapage *__get_metapage(struct inode *inode, unsigned long lblock,
inode->i_ino, lblock, absolute);

l2bsize = inode->i_blkbits;
- l2BlocksPerPage = PAGE_CACHE_SHIFT - l2bsize;
+ l2BlocksPerPage = PAGE_SHIFT - l2bsize;
page_index = lblock >> l2BlocksPerPage;
page_offset = (lblock - (page_index << l2BlocksPerPage)) << l2bsize;
- if ((page_offset + size) > PAGE_CACHE_SIZE) {
+ if ((page_offset + size) > PAGE_SIZE) {
jfs_err("MetaData crosses page boundary!!");
jfs_err("lblock = %lx, size = %d", lblock, size);
dump_stack();
@@ -621,7 +621,7 @@ struct metapage *__get_metapage(struct inode *inode, unsigned long lblock,
mapping = inode->i_mapping;
}

- if (new && (PSIZE == PAGE_CACHE_SIZE)) {
+ if (new && (PSIZE == PAGE_SIZE)) {
page = grab_cache_page(mapping, page_index);
if (!page) {
jfs_err("grab_cache_page failed!");
@@ -693,7 +693,7 @@ unlock:
void grab_metapage(struct metapage * mp)
{
jfs_info("grab_metapage: mp = 0x%p", mp);
- page_cache_get(mp->page);
+ get_page(mp->page);
lock_page(mp->page);
mp->count++;
lock_metapage(mp);
@@ -706,12 +706,12 @@ void force_metapage(struct metapage *mp)
jfs_info("force_metapage: mp = 0x%p", mp);
set_bit(META_forcewrite, &mp->flag);
clear_bit(META_sync, &mp->flag);
- page_cache_get(page);
+ get_page(page);
lock_page(page);
set_page_dirty(page);
write_one_page(page, 1);
clear_bit(META_forcewrite, &mp->flag);
- page_cache_release(page);
+ put_page(page);
}

void hold_metapage(struct metapage *mp)
@@ -726,7 +726,7 @@ void put_metapage(struct metapage *mp)
unlock_page(mp->page);
return;
}
- page_cache_get(mp->page);
+ get_page(mp->page);
mp->count++;
lock_metapage(mp);
unlock_page(mp->page);
@@ -746,7 +746,7 @@ void release_metapage(struct metapage * mp)
assert(mp->count);
if (--mp->count || mp->nohomeok) {
unlock_page(page);
- page_cache_release(page);
+ put_page(page);
return;
}

@@ -764,13 +764,13 @@ void release_metapage(struct metapage * mp)
drop_metapage(page, mp);

unlock_page(page);
- page_cache_release(page);
+ put_page(page);
}

void __invalidate_metapages(struct inode *ip, s64 addr, int len)
{
sector_t lblock;
- int l2BlocksPerPage = PAGE_CACHE_SHIFT - ip->i_blkbits;
+ int l2BlocksPerPage = PAGE_SHIFT - ip->i_blkbits;
int BlocksPerPage = 1 << l2BlocksPerPage;
/* All callers are interested in block device's mapping */
struct address_space *mapping =
@@ -788,7 +788,7 @@ void __invalidate_metapages(struct inode *ip, s64 addr, int len)
page = find_lock_page(mapping, lblock >> l2BlocksPerPage);
if (!page)
continue;
- for (offset = 0; offset < PAGE_CACHE_SIZE; offset += PSIZE) {
+ for (offset = 0; offset < PAGE_SIZE; offset += PSIZE) {
mp = page_to_mp(page, offset);
if (!mp)
continue;
@@ -803,7 +803,7 @@ void __invalidate_metapages(struct inode *ip, s64 addr, int len)
remove_from_logsync(mp);
}
unlock_page(page);
- page_cache_release(page);
+ put_page(page);
}
}

diff --git a/fs/jfs/jfs_metapage.h b/fs/jfs/jfs_metapage.h
index 337e9e51ac06..a869fb4a20d6 100644
--- a/fs/jfs/jfs_metapage.h
+++ b/fs/jfs/jfs_metapage.h
@@ -106,7 +106,7 @@ static inline void metapage_nohomeok(struct metapage *mp)
lock_page(page);
if (!mp->nohomeok++) {
mark_metapage_dirty(mp);
- page_cache_get(page);
+ get_page(page);
wait_on_page_writeback(page);
}
unlock_page(page);
@@ -128,7 +128,7 @@ static inline void metapage_wait_for_io(struct metapage *mp)
static inline void _metapage_homeok(struct metapage *mp)
{
if (!--mp->nohomeok)
- page_cache_release(mp->page);
+ put_page(mp->page);
}

static inline void metapage_homeok(struct metapage *mp)
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index 4f5d85ba8e23..78d599198bf5 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -596,7 +596,7 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
* Page cache is indexed by long.
* I would use MAX_LFS_FILESIZE, but it's only half as big
*/
- sb->s_maxbytes = min(((u64) PAGE_CACHE_SIZE << 32) - 1,
+ sb->s_maxbytes = min(((u64) PAGE_SIZE << 32) - 1,
(u64)sb->s_maxbytes);
#endif
sb->s_time_gran = 1;
--
2.7.0