Re: [PATCH 4/7] Use vfs __set_page_dirty interface instead of doingit inside filesystem

From: Michal Hocko
Date: Wed Jul 04 2012 - 10:27:26 EST


On Thu 28-06-12 19:03:43, Sha Zhengju wrote:
> From: Sha Zhengju <handai.szj@xxxxxxxxxx>
>
> Following we will treat SetPageDirty and dirty page accounting as an integrated
> operation. Filesystems had better use vfs interface directly to avoid those details.
>
> Signed-off-by: Sha Zhengju <handai.szj@xxxxxxxxxx>
> ---
> fs/buffer.c | 2 +-
> fs/ceph/addr.c | 20 ++------------------
> include/linux/buffer_head.h | 2 ++
> 3 files changed, 5 insertions(+), 19 deletions(-)
>
> diff --git a/fs/buffer.c b/fs/buffer.c
> index e8d96b8..55522dd 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -610,7 +610,7 @@ EXPORT_SYMBOL(mark_buffer_dirty_inode);
> * If warn is true, then emit a warning if the page is not uptodate and has
> * not been truncated.
> */
> -static int __set_page_dirty(struct page *page,
> +int __set_page_dirty(struct page *page,
> struct address_space *mapping, int warn)
> {
> if (unlikely(!mapping))
> diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
> index 8b67304..d028fbe 100644
> --- a/fs/ceph/addr.c
> +++ b/fs/ceph/addr.c
> @@ -5,6 +5,7 @@
> #include <linux/mm.h>
> #include <linux/pagemap.h>
> #include <linux/writeback.h> /* generic_writepages */
> +#include <linux/buffer_head.h>
> #include <linux/slab.h>
> #include <linux/pagevec.h>
> #include <linux/task_io_accounting_ops.h>
> @@ -73,14 +74,8 @@ static int ceph_set_page_dirty(struct page *page)
> int undo = 0;
> struct ceph_snap_context *snapc;
>
> - if (unlikely(!mapping))
> - return !TestSetPageDirty(page);
> -
> - if (TestSetPageDirty(page)) {
> - dout("%p set_page_dirty %p idx %lu -- already dirty\n",
> - mapping->host, page, page->index);

I am not familiar with the code but this looks we loose an information
about something bad(?) is going on?

> + if (!__set_page_dirty(page, mapping, 1))
> return 0;
> - }
>
> inode = mapping->host;
> ci = ceph_inode(inode);
--
Michal Hocko
SUSE Labs
SUSE LINUX s.r.o.
Lihovarska 1060/12
190 00 Praha 9
Czech Republic
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