Re: [PATCH 3/3] fs: Fix remaining filesystems to wait for stablepage writeback

From: Jan Kara
Date: Thu Nov 01 2012 - 08:37:03 EST


On Thu 01-11-12 00:58:29, Darrick J. Wong wrote:
> Fix up the filesystems that provide their own ->page_mkwrite handlers to
> provide stable page writes if necessary.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
> fs/9p/vfs_file.c | 1 +
> fs/afs/write.c | 4 ++--
> fs/ceph/addr.c | 1 +
> fs/cifs/file.c | 1 +
> fs/ocfs2/mmap.c | 1 +
> fs/ubifs/file.c | 4 ++--
> 6 files changed, 8 insertions(+), 4 deletions(-)
>
>
> diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
> index c2483e9..aa253f0 100644
> --- a/fs/9p/vfs_file.c
> +++ b/fs/9p/vfs_file.c
> @@ -620,6 +620,7 @@ v9fs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
> lock_page(page);
> if (page->mapping != inode->i_mapping)
> goto out_unlock;
> + wait_on_stable_page_write(page);
>
> return VM_FAULT_LOCKED;
> out_unlock:
> diff --git a/fs/afs/write.c b/fs/afs/write.c
> index 9aa52d9..39eb2a4 100644
> --- a/fs/afs/write.c
> +++ b/fs/afs/write.c
> @@ -758,7 +758,7 @@ int afs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
> #ifdef CONFIG_AFS_FSCACHE
> fscache_wait_on_page_write(vnode->cache, page);
> #endif
> -
> + wait_on_stable_page_write(page);
> _leave(" = 0");
> - return 0;
> + return VM_FAULT_LOCKED;
> }
Oh, I missed these two since I've got confused by
fscache_wait_on_page_write().

> diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c
> index 47a87dd..a0027b1 100644
> --- a/fs/ocfs2/mmap.c
> +++ b/fs/ocfs2/mmap.c
> @@ -124,6 +124,7 @@ static int __ocfs2_page_mkwrite(struct file *file, struct buffer_head *di_bh,
> fsdata);
> BUG_ON(ret != len);
> ret = VM_FAULT_LOCKED;
> + wait_on_stable_page_write(page);
> out:
> return ret;
> }
Actually, this is not so easy. ocfs2 doesn't use
grab_cache_page_write_begin() so you have to modify write_begin() path as
well. And then you don't have to modify __ocfs2_page_mkwrite() because it
uses ocfs2_write_begin(). Preferably teach it to use
grab_cache_page_write_begin()...

And I think you are missing ncpfs. Because ncp_file_mmap does not set
.mkwrite - it should use filemap_page_mkwrite() I think.

Honza
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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