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/affs/file.c | 26 +++++++++++++-------------
1 file changed, 13 insertions(+), 13 deletions(-)
diff --git a/fs/affs/file.c b/fs/affs/file.c
index 22fc7c802d69..0cde550050e8 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -510,9 +510,9 @@ affs_do_readpage_ofs(struct page *page, unsigned to)
pr_debug("%s(%lu, %ld, 0, %d)\n", __func__, inode->i_ino,
page->index, to);
- BUG_ON(to > PAGE_CACHE_SIZE);
+ BUG_ON(to > PAGE_SIZE);
bsize = AFFS_SB(sb)->s_data_blksize;
- tmp = page->index << PAGE_CACHE_SHIFT;
+ tmp = page->index << PAGE_SHIFT;
bidx = tmp / bsize;
boff = tmp % bsize;
@@ -613,10 +613,10 @@ affs_readpage_ofs(struct file *file, struct page *page)
int err;
pr_debug("%s(%lu, %ld)\n", __func__, inode->i_ino, page->index);
- to = PAGE_CACHE_SIZE;
- if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) {
- to = inode->i_size & ~PAGE_CACHE_MASK;
- memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to);
+ to = PAGE_SIZE;
+ if (((page->index + 1) << PAGE_SHIFT) > inode->i_size) {
+ to = inode->i_size & ~PAGE_MASK;
+ memset(page_address(page) + to, 0, PAGE_SIZE - to);
}
err = affs_do_readpage_ofs(page, to);
@@ -646,7 +646,7 @@ static int affs_write_begin_ofs(struct file *file, struct address_space *mapping
return err;
}
- index = pos >> PAGE_CACHE_SHIFT;
+ index = pos >> PAGE_SHIFT;
page = grab_cache_page_write_begin(mapping, index, flags);
if (!page)
return -ENOMEM;
@@ -656,10 +656,10 @@ static int affs_write_begin_ofs(struct file *file, struct address_space *mapping
return 0;
/* XXX: inefficient but safe in the face of short writes */
- err = affs_do_readpage_ofs(page, PAGE_CACHE_SIZE);
+ err = affs_do_readpage_ofs(page, PAGE_SIZE);
if (err) {
unlock_page(page);
- page_cache_release(page);
+ put_page(page);
}
return err;
}
@@ -677,7 +677,7 @@ static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
u32 tmp;
int written;
- from = pos & (PAGE_CACHE_SIZE - 1);
+ from = pos & (PAGE_SIZE - 1);
to = pos + len;
/*
* XXX: not sure if this can handle short copies (len < copied), but
@@ -692,7 +692,7 @@ static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
bh = NULL;
written = 0;
- tmp = (page->index << PAGE_CACHE_SHIFT) + from;
+ tmp = (page->index << PAGE_SHIFT) + from;
bidx = tmp / bsize;
boff = tmp % bsize;
if (boff) {
@@ -788,13 +788,13 @@ static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
done:
affs_brelse(bh);
- tmp = (page->index << PAGE_CACHE_SHIFT) + from;
+ tmp = (page->index << PAGE_SHIFT) + from;
if (tmp > inode->i_size)
inode->i_size = AFFS_I(inode)->mmu_private = tmp;
err_first_bh:
unlock_page(page);
- page_cache_release(page);
+ put_page(page);
return written;
--
2.7.0
--
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