> -----Original Message----- > From: Pavel Shilovsky [mailto:piastryyy@xxxxxxxxx] > Sent: Wednesday, November 1, 2017 9:50 AM > To: Long Li <longli@xxxxxxxxxxxxx> > Cc: Steve French <sfrench@xxxxxxxxx>; linux-cifs <linux- > cifs@xxxxxxxxxxxxxxx>; samba-technical <samba-technical@xxxxxxxxxxxxxxx>; > Kernel Mailing List <linux-kernel@xxxxxxxxxxxxxxx>; linux- > rdma@xxxxxxxxxxxxxxx; Tom Talpey <ttalpey@xxxxxxxxxxxxx>; Matthew > Wilcox <mawilcox@xxxxxxxxxxxxx>; Stephen Hemminger > <sthemmin@xxxxxxxxxxxxx>; Long Li <longli@xxxxxxxxxxxxx> > Subject: Re: [Patch v5 19/21] CIFS: SMBD: Read correct returned data length > for RDMA write (SMB read) I/O > > 2017-10-18 16:09 GMT-07:00 Long Li <longli@xxxxxxxxxxxxxxxxxxxxxx>: > > From: Long Li <longli@xxxxxxxxxxxxx> > > > > This patch is for preparing upper layer doing SMB read via RDMA write. > > > > When RDMA write is used for SMB read, the returned data length is in > > DataRemaining in the response packet. Reading it properly by adding a > > parameter to specifiy where the returned data length is. > > > > Add the defition for memory registration to wdata and return the > > correct length based on if RDMA write is used. > > > > Signed-off-by: Long Li <longli@xxxxxxxxxxxxx> > > --- > > fs/cifs/cifsglob.h | 13 +++++++++++-- fs/cifs/cifssmb.c | 7 > > ++++++- fs/cifs/smb1ops.c | 6 +++++- fs/cifs/smb2ops.c | 12 > > ++++++++++-- > > 4 files changed, 32 insertions(+), 6 deletions(-) > > > > diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index > > 2ae7d02..ddf83d8 100644 > > --- a/fs/cifs/cifsglob.h > > +++ b/fs/cifs/cifsglob.h > > @@ -228,8 +228,14 @@ struct smb_version_operations { > > __u64 (*get_next_mid)(struct TCP_Server_Info *); > > /* data offset from read response message */ > > unsigned int (*read_data_offset)(char *); > > - /* data length from read response message */ > > - unsigned int (*read_data_length)(char *); > > + /* > > + * Data length from read response message > > + * When in_remaining is true, the returned data length is in > > + * message field DataRemaining for out-of-band data read (e.g > through > > + * Memory Registration RDMA write in SMBD). > > + * Otherwise, the returned data length is in message field DataLength. > > + */ > > + unsigned int (*read_data_length)(char *, bool in_remaining); > > /* map smb to linux error */ > > int (*map_error)(char *, bool); > > /* find mid corresponding to the response message */ @@ > > -1148,6 +1154,9 @@ struct cifs_readdata { > > struct cifs_readdata *rdata, > > struct iov_iter *iter); > > struct kvec iov[2]; > > +#ifdef CONFIG_CIFS_SMB_DIRECT > > + struct smbd_mr *mr; > > +#endif > > unsigned int pagesz; > > unsigned int tailsz; > > unsigned int credits; > > diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index > > 08ff56a..a343db4 100644 > > --- a/fs/cifs/cifssmb.c > > +++ b/fs/cifs/cifssmb.c > > @@ -1533,8 +1533,13 @@ cifs_readv_receive(struct TCP_Server_Info > *server, struct mid_q_entry *mid) > > rdata->iov[0].iov_base, server->total_read); > > > > /* how much data is in the response? */ > > - data_len = server->ops->read_data_length(buf); > > +#ifdef CONFIG_CIFS_SMB_DIRECT > > + data_len = server->ops->read_data_length(buf, rdata->mr); > > + if (!rdata->mr && (data_offset + data_len > buflen)) { #else > > + data_len = server->ops->read_data_length(buf, false); > > if (data_offset + data_len > buflen) { > > +#endif > > /* data_len is corrupt -- discard frame */ > > rdata->result = -EIO; > > return cifs_readv_discard(server, mid); diff --git > > a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c index a723df3..b718bb8 100644 > > --- a/fs/cifs/smb1ops.c > > +++ b/fs/cifs/smb1ops.c > > @@ -87,9 +87,13 @@ cifs_read_data_offset(char *buf) } > > > > static unsigned int > > -cifs_read_data_length(char *buf) > > +cifs_read_data_length(char *buf, bool in_remaining) > > { > > READ_RSP *rsp = (READ_RSP *)buf; > > + if (in_remaining) { > > + cifs_dbg(VFS, "Invalid SMB1 calling path, check > > + code\n"); > > I would suggest to do WARN_ON(1) instead. I will make the change. > > > + return 0; > > + } > > return (le16_to_cpu(rsp->DataLengthHigh) << 16) + > > le16_to_cpu(rsp->DataLength); } > > > -- > Best regards, > Pavel Shilovsky ��.n��������+%������w��{.n�����{���fk��ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
