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: <[email protected]>
Signed-off-by: David Disseldorp <[email protected]>
Signed-off-by: Steve French <[email protected]>
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 <[email protected]> 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 <[email protected]>
> ---
> 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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--
Thanks,
Steve
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