On Thu, 2013-07-04 at 14:43 -0500, Steve French wrote:
> I merged an equivalent but slightly smaller version of your patch into
> cifs-2.6.git (see below) and added stable since we should not be
> returning nlink of 0. Let me know if any objections.
>
> [CIFS] use sensible file nlink values if unprovided
>
> Certain servers may not set the NumberOfLinks field in query file/path
> info responses. In such a case, cifs_inode_needs_reval() assumes that
> all regular files are hardlinks and triggers revalidation, leading to
> excessive and unnecessary network traffic.
>
> This change hardcodes cf_nlink (and subsequently i_nlink) when not
> returned by the server, similar to what already occurs in cifs_mkdir().
>
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: David Disseldorp <ddiss@xxxxxxx>
> Signed-off-by: Steve French <smfrench@xxxxxxxxx>
>
> diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
> index 20efd81..449b6cf 100644
> --- a/fs/cifs/inode.c
> +++ b/fs/cifs/inode.c
> @@ -558,6 +558,11 @@ cifs_all_info_to_fattr(struct cifs_fattr *fattr,
> FILE_ALL_INFO *info,
> fattr->cf_mode &= ~(S_IWUGO);
>
> fattr->cf_nlink = le32_to_cpu(info->NumberOfLinks);
> + if (fattr->cf_nlink < 1) {
> + cifs_dbg(1, "replacing bogus file nlink value %u\n",
> + fattr->cf_nlink);
> + fattr->cf_nlink = 1;
> + }
> }
>
> fattr->cf_uid = cifs_sb->mnt_uid;
>
>
> On Thu, Jul 4, 2013 at 1:06 PM, David Disseldorp <ddiss@xxxxxxx> wrote:
> > Certain servers may not set the NumberOfLinks field in query file/path
> > info responses. In such a case, cifs_inode_needs_reval() assumes that
> > all regular files are hardlinks and triggers revalidation, leading to
> > excessive and unnecessary network traffic.
> >
> > This change hardcodes cf_nlink (and subsequently i_nlink) when not
> > returned by the server, similar to what already occurs in cifs_mkdir().
> >
> > Signed-off-by: David Disseldorp <ddiss@xxxxxxx>
> > ---
> > fs/cifs/inode.c | 10 ++++++++--
> > 1 file changed, 8 insertions(+), 2 deletions(-)
> >
> > diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
> > index 6f37228..8c48027 100644
> > --- a/fs/cifs/inode.c
> > +++ b/fs/cifs/inode.c
> > @@ -532,6 +532,8 @@ cifs_all_info_to_fattr(struct cifs_fattr *fattr, FILE_ALL_INFO *info,
> > fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
> > fattr->cf_createtime = le64_to_cpu(info->CreationTime);
> >
> > + fattr->cf_nlink = le32_to_cpu(info->NumberOfLinks);
> > +
> > if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
> > fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
> > fattr->cf_dtype = DT_DIR;
> > @@ -542,9 +544,13 @@ cifs_all_info_to_fattr(struct cifs_fattr *fattr, FILE_ALL_INFO *info,
> > /* clear write bits if ATTR_READONLY is set */
> > if (fattr->cf_cifsattrs & ATTR_READONLY)
> > fattr->cf_mode &= ~(S_IWUGO);
> > - }
> >
> > - fattr->cf_nlink = le32_to_cpu(info->NumberOfLinks);
> > + if (fattr->cf_nlink < 1) {
> > + cFYI(1, "replacing bogus file nlink value %u",
> > + fattr->cf_nlink);
> > + fattr->cf_nlink = 1;
> > + }
> > + }
> >
> > fattr->cf_uid = cifs_sb->mnt_uid;
> > fattr->cf_gid = cifs_sb->mnt_gid;
> > --
> > 1.8.1.4
> >
> > --
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>
>
>
What about readdir? Is a similar fix needed in cifs_fill_common_info or
one of its callers?
--
Jeff Layton <jlayton@xxxxxxxxxx>
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