> -----邮件原件-----
> 发件人: Jeff Layton <jlayton@xxxxxxxxxx>
> 发送时间: 2024年1月30日 23:50
> 收件人: Chen, Hanxiao/陈 晗霄 <chenhx.fnst@xxxxxxxxxxx>; Trond Myklebust
> <trond.myklebust@xxxxxxxxxxxxxxx>; Anna Schumaker <anna@xxxxxxxxxx>
> 抄送: linux-nfs@xxxxxxxxxxxxxxx; Dave Wysochanski <dwysocha@xxxxxxxxxx>;
> David Howells <dhowells@xxxxxxxxxx>
> 主题: Re: [PATCH v2] nfs: fix regression in handling of fsc= option in NFSv4
>
> On Tue, 2024-01-30 at 23:46 +0800, Chen Hanxiao wrote:
> > Setting the uniquifier for fscache via the fsc= mount
> > option is currently broken in NFSv4.
> >
> > Fix this by passing fscache_uniq to root_fc if possible.
> >
> > Signed-off-by: Chen Hanxiao <chenhx.fnst@xxxxxxxxxxx>
> > ---
> > v2:
> > use kmemdup_nul instead of snprintf
> >
> > fs/nfs/nfs4super.c | 24 ++++++++++++++++++++++++
> > 1 file changed, 24 insertions(+)
> >
> > diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c
> > index d09bcfd7db89..4a23d9143d5a 100644
> > --- a/fs/nfs/nfs4super.c
> > +++ b/fs/nfs/nfs4super.c
> > @@ -145,6 +145,7 @@ static int do_nfs4_mount(struct nfs_server *server,
> > const char *export_path)
> > {
> > struct nfs_fs_context *root_ctx;
> > + struct nfs_fs_context *ctx;
> > struct fs_context *root_fc;
> > struct vfsmount *root_mnt;
> > struct dentry *dentry;
> > @@ -157,6 +158,12 @@ static int do_nfs4_mount(struct nfs_server *server,
> > .dirfd = -1,
> > };
> >
> > + struct fs_parameter param_fsc = {
> > + .key = "fsc",
> > + .type = fs_value_is_string,
> > + .dirfd = -1,
> > + };
> > +
> > if (IS_ERR(server))
> > return PTR_ERR(server);
> >
> > @@ -168,9 +175,26 @@ static int do_nfs4_mount(struct nfs_server *server,
> > kfree(root_fc->source);
> > root_fc->source = NULL;
> >
> > + ctx = nfs_fc2context(fc);
> > root_ctx = nfs_fc2context(root_fc);
> > root_ctx->internal = true;
> > root_ctx->server = server;
> > +
> > + if (ctx->fscache_uniq) {
> > + len = strlen(ctx->fscache_uniq) + 1;
> > + param_fsc.size = len;
>
> In the other patch you were setting .size to the return value from
> snprintf. That does not include the NUL byte. You're including it here
> though. Which way is correct?
>
It should be:
len = strlen(ctx->fscache_uniq).
param_fsc.size = len;
for kmemdup_nul case.
Will be fixed in v3.
Sorry for the noise.
Regards
- Chen
> > + param_fsc.string = kmemdup_nul(ctx->fscache_uniq, len,
> GFP_KERNEL);
> > + if (param_fsc.string == NULL) {
> > + put_fs_context(root_fc);
> > + return -ENOMEM;
> > + }
> > + ret = vfs_parse_fs_param(root_fc, ¶m_fsc);
> > + kfree(param_fsc.string);
> > + if (ret < 0) {
> > + put_fs_context(root_fc);
> > + return ret;
> > + }
> > + }
> > /* We leave export_path unset as it's not used to find the root. */
> >
> > len = strlen(hostname) + 5;
>
> --
> Jeff Layton <jlayton@xxxxxxxxxx>
