[PATCH 42/71] isofs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
From: Kirill A. Shutemov
Date: Sun Mar 20 2016 - 14:53:51 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>
---
fs/isofs/compress.c | 36 ++++++++++++++++++------------------
fs/isofs/inode.c | 2 +-
2 files changed, 19 insertions(+), 19 deletions(-)
diff --git a/fs/isofs/compress.c b/fs/isofs/compress.c
index f311bf084015..2e4e834d1a98 100644
--- a/fs/isofs/compress.c
+++ b/fs/isofs/compress.c
@@ -26,7 +26,7 @@
#include "zisofs.h"
/* This should probably be global. */
-static char zisofs_sink_page[PAGE_CACHE_SIZE];
+static char zisofs_sink_page[PAGE_SIZE];
/*
* This contains the zlib memory allocation and the mutex for the
@@ -70,11 +70,11 @@ static loff_t zisofs_uncompress_block(struct inode *inode, loff_t block_start,
for ( i = 0 ; i < pcount ; i++ ) {
if (!pages[i])
continue;
- memset(page_address(pages[i]), 0, PAGE_CACHE_SIZE);
+ memset(page_address(pages[i]), 0, PAGE_SIZE);
flush_dcache_page(pages[i]);
SetPageUptodate(pages[i]);
}
- return ((loff_t)pcount) << PAGE_CACHE_SHIFT;
+ return ((loff_t)pcount) << PAGE_SHIFT;
}
/* Because zlib is not thread-safe, do all the I/O at the top. */
@@ -121,11 +121,11 @@ static loff_t zisofs_uncompress_block(struct inode *inode, loff_t block_start,
if (pages[curpage]) {
stream.next_out = page_address(pages[curpage])
+ poffset;
- stream.avail_out = PAGE_CACHE_SIZE - poffset;
+ stream.avail_out = PAGE_SIZE - poffset;
poffset = 0;
} else {
stream.next_out = (void *)&zisofs_sink_page;
- stream.avail_out = PAGE_CACHE_SIZE;
+ stream.avail_out = PAGE_SIZE;
}
}
if (!stream.avail_in) {
@@ -220,14 +220,14 @@ static int zisofs_fill_pages(struct inode *inode, int full_page, int pcount,
* pages with the data we have anyway...
*/
start_off = page_offset(pages[full_page]);
- end_off = min_t(loff_t, start_off + PAGE_CACHE_SIZE, inode->i_size);
+ end_off = min_t(loff_t, start_off + PAGE_SIZE, inode->i_size);
cstart_block = start_off >> zisofs_block_shift;
cend_block = (end_off + (1 << zisofs_block_shift) - 1)
>> zisofs_block_shift;
- WARN_ON(start_off - (full_page << PAGE_CACHE_SHIFT) !=
- ((cstart_block << zisofs_block_shift) & PAGE_CACHE_MASK));
+ WARN_ON(start_off - (full_page << PAGE_SHIFT) !=
+ ((cstart_block << zisofs_block_shift) & PAGE_MASK));
/* Find the pointer to this specific chunk */
/* Note: we're not using isonum_731() here because the data is known aligned */
@@ -260,10 +260,10 @@ static int zisofs_fill_pages(struct inode *inode, int full_page, int pcount,
ret = zisofs_uncompress_block(inode, block_start, block_end,
pcount, pages, poffset, &err);
poffset += ret;
- pages += poffset >> PAGE_CACHE_SHIFT;
- pcount -= poffset >> PAGE_CACHE_SHIFT;
- full_page -= poffset >> PAGE_CACHE_SHIFT;
- poffset &= ~PAGE_CACHE_MASK;
+ pages += poffset >> PAGE_SHIFT;
+ pcount -= poffset >> PAGE_SHIFT;
+ full_page -= poffset >> PAGE_SHIFT;
+ poffset &= ~PAGE_MASK;
if (err) {
brelse(bh);
@@ -282,7 +282,7 @@ static int zisofs_fill_pages(struct inode *inode, int full_page, int pcount,
if (poffset && *pages) {
memset(page_address(*pages) + poffset, 0,
- PAGE_CACHE_SIZE - poffset);
+ PAGE_SIZE - poffset);
flush_dcache_page(*pages);
SetPageUptodate(*pages);
}
@@ -302,12 +302,12 @@ static int zisofs_readpage(struct file *file, struct page *page)
int i, pcount, full_page;
unsigned int zisofs_block_shift = ISOFS_I(inode)->i_format_parm[1];
unsigned int zisofs_pages_per_cblock =
- PAGE_CACHE_SHIFT <= zisofs_block_shift ?
- (1 << (zisofs_block_shift - PAGE_CACHE_SHIFT)) : 0;
+ PAGE_SHIFT <= zisofs_block_shift ?
+ (1 << (zisofs_block_shift - PAGE_SHIFT)) : 0;
struct page *pages[max_t(unsigned, zisofs_pages_per_cblock, 1)];
pgoff_t index = page->index, end_index;
- end_index = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ end_index = (inode->i_size + PAGE_SIZE - 1) >> PAGE_SHIFT;
/*
* If this page is wholly outside i_size we just return zero;
* do_generic_file_read() will handle this for us
@@ -318,7 +318,7 @@ static int zisofs_readpage(struct file *file, struct page *page)
return 0;
}
- if (PAGE_CACHE_SHIFT <= zisofs_block_shift) {
+ if (PAGE_SHIFT <= zisofs_block_shift) {
/* We have already been given one page, this is the one
we must do. */
full_page = index & (zisofs_pages_per_cblock - 1);
@@ -351,7 +351,7 @@ static int zisofs_readpage(struct file *file, struct page *page)
kunmap(pages[i]);
unlock_page(pages[i]);
if (i != full_page)
- page_cache_release(pages[i]);
+ put_page(pages[i]);
}
}
diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c
index bcd2d41b318a..131dedc920d8 100644
--- a/fs/isofs/inode.c
+++ b/fs/isofs/inode.c
@@ -1021,7 +1021,7 @@ int isofs_get_blocks(struct inode *inode, sector_t iblock,
* the page with useless information without generating any
* I/O errors.
*/
- if (b_off > ((inode->i_size + PAGE_CACHE_SIZE - 1) >> ISOFS_BUFFER_BITS(inode))) {
+ if (b_off > ((inode->i_size + PAGE_SIZE - 1) >> ISOFS_BUFFER_BITS(inode))) {
printk(KERN_DEBUG "%s: block >= EOF (%lu, %llu)\n",
__func__, b_off,
(unsigned long long)inode->i_size);
--
2.7.0