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: Nadia Yvette Chambers <nyc@xxxxxxxxxxxxxx>
---
fs/hugetlbfs/inode.c | 10 +++++-----
mm/hugetlb.c | 8 ++++----
2 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index e1f465a389d5..4ea71eba40a5 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -213,12 +213,12 @@ hugetlbfs_read_actor(struct page *page, unsigned long offset,
int i, chunksize;
/* Find which 4k chunk and offset with in that chunk */
- i = offset >> PAGE_CACHE_SHIFT;
- offset = offset & ~PAGE_CACHE_MASK;
+ i = offset >> PAGE_SHIFT;
+ offset = offset & ~PAGE_MASK;
while (size) {
size_t n;
- chunksize = PAGE_CACHE_SIZE;
+ chunksize = PAGE_SIZE;
if (offset)
chunksize -= offset;
if (chunksize > size)
@@ -237,7 +237,7 @@ hugetlbfs_read_actor(struct page *page, unsigned long offset,
/*
* Support for read() - Find the page attached to f_mapping and copy out the
* data. Its *very* similar to do_generic_mapping_read(), we can't use that
- * since it has PAGE_CACHE_SIZE assumptions.
+ * since it has PAGE_SIZE assumptions.
*/
static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
@@ -285,7 +285,7 @@ static ssize_t hugetlbfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
* We have the page, copy it to user space buffer.
*/
copied = hugetlbfs_read_actor(page, offset, to, nr);
- page_cache_release(page);
+ put_page(page);
}
offset += copied;
retval += copied;
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 06058eaa173b..19d0d08b396f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3346,7 +3346,7 @@ retry_avoidcopy:
old_page != pagecache_page)
outside_reserve = 1;
- page_cache_get(old_page);
+ get_page(old_page);
/*
* Drop page table lock as buddy allocator may be called. It will
@@ -3364,7 +3364,7 @@ retry_avoidcopy:
* may get SIGKILLed if it later faults.
*/
if (outside_reserve) {
- page_cache_release(old_page);
+ put_page(old_page);
BUG_ON(huge_pte_none(pte));
unmap_ref_private(mm, vma, old_page, address);
BUG_ON(huge_pte_none(pte));
@@ -3425,9 +3425,9 @@ retry_avoidcopy:
spin_unlock(ptl);
mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
out_release_all:
- page_cache_release(new_page);
+ put_page(new_page);
out_release_old:
- page_cache_release(old_page);
+ put_page(old_page);
spin_lock(ptl); /* Caller expects lock to be held */
return ret;
--
2.7.0
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