| From | "Kirill A. Shutemov" <> | Subject | [PATCH 68/71] uprobes: get rid of PAGE_CACHE_* and page_cache_{get,release} macros | Date | Sun, 20 Mar 2016 21:41:15 +0300 |
| |
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@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com> --- kernel/events/uprobes.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 5f6ce931f1ea..9be1cba0eb11 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -321,7 +321,7 @@ retry: copy_to_page(new_page, vaddr, &opcode, UPROBE_SWBP_INSN_SIZE); ret = __replace_page(vma, vaddr, old_page, new_page); - page_cache_release(new_page); + put_page(new_page); put_old: put_page(old_page); @@ -539,14 +539,14 @@ static int __copy_insn(struct address_space *mapping, struct file *filp, * see uprobe_register(). */ if (mapping->a_ops->readpage) - page = read_mapping_page(mapping, offset >> PAGE_CACHE_SHIFT, filp); + page = read_mapping_page(mapping, offset >> PAGE_SHIFT, filp); else - page = shmem_read_mapping_page(mapping, offset >> PAGE_CACHE_SHIFT); + page = shmem_read_mapping_page(mapping, offset >> PAGE_SHIFT); if (IS_ERR(page)) return PTR_ERR(page); copy_from_page(page, offset, insn, nbytes); - page_cache_release(page); + put_page(page); return 0; } -- 2.7.0
|