[PATCH 66/71] hugetlb: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
From: Kirill A. Shutemov <hidden>
Date: 2016-03-20 18:41:13
Also in:
linux-fsdevel, lkml
Subsystem:
filesystems (vfs and infrastructure), hugetlb subsystem, memory management, the rest · Maintainers:
Alexander Viro, Christian Brauner, Muchun Song, Oscar Salvador, Andrew Morton, Linus Torvalds
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 <redacted>
Cc: Nadia Yvette Chambers <redacted>
---
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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