tentatively merged to cifs-2.6.git for-next pending testing and
additional review
On Fri, Aug 30, 2024 at 7:10 PM Enzo Matsumiya <ematsumiya@xxxxxxx> wrote:
>
> Some operations return -EEXIST for a non-existing dir/file because of
> cached attributes.
>
> Fix this by forcing dentry revalidation when nohandlecache is set.
>
> Bug/reproducer:
> Azure Files share, attribute caching timeout is 30s (as
> suggested by Azure), 2 clients mounting the same share.
>
> tcon->nohandlecache is set by cifs_get_tcon() because no directory
> leasing capability is offered.
>
> # client 1 and 2
> $ mount.cifs -o ...,actimeo=30 //server/share /mnt
> $ cd /mnt
>
> # client 1
> $ mkdir dir1
>
> # client 2
> $ ls
> dir1
>
> # client 1
> $ mv dir1 dir2
>
> # client 2
> $ mkdir dir1
> mkdir: cannot create directory ‘dir1’: File exists
> $ ls
> dir2
> $ mkdir dir1
> mkdir: cannot create directory ‘dir1’: File exists
>
> "mkdir dir1" eventually works after 30s (when attribute cache
> expired).
>
> The same behaviour can be observed with files if using some
> non-overwritting operation (e.g. "rm -i").
>
> Signed-off-by: Enzo Matsumiya <ematsumiya@xxxxxxx>
> Tested-by: Henrique Carvalho <henrique.carvalho@xxxxxxxx>
> ---
> fs/smb/client/inode.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c
> index dd0afa23734c..5f9c5525385f 100644
> --- a/fs/smb/client/inode.c
> +++ b/fs/smb/client/inode.c
> @@ -2427,6 +2427,9 @@ cifs_dentry_needs_reval(struct dentry *dentry)
> if (!lookupCacheEnabled)
> return true;
>
> + if (tcon->nohandlecache)
> + return true;
> +
> if (!open_cached_dir_by_dentry(tcon, dentry->d_parent, &cfid)) {
> spin_lock(&cfid->fid_lock);
> if (cfid->time && cifs_i->time > cfid->time) {
> --
> 2.46.0
>
--
Thanks,
Steve
