diff mbox series

[1/3] cifs: prepare SMB2_query_directory to be used with compounding

Message ID 20191204225410.17514-2-lsahlber@redhat.com
State New, archived
Headers show
Series use compounding to speed up readdir() | expand

Commit Message

Ronnie Sahlberg Dec. 4, 2019, 10:54 p.m. UTC
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
---
 fs/cifs/smb2pdu.c   | 108 +++++++++++++++++++++++++++++++++++-----------------
 fs/cifs/smb2pdu.h   |   2 +
 fs/cifs/smb2proto.h |   5 +++
 3 files changed, 80 insertions(+), 35 deletions(-)

Comments

Pavel Shilovsky Dec. 23, 2019, 11:48 p.m. UTC | #1
ср, 4 дек. 2019 г. в 14:54, Ronnie Sahlberg <lsahlber@redhat.com>:
>
> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
> ---
>  fs/cifs/smb2pdu.c   | 108 +++++++++++++++++++++++++++++++++++-----------------
>  fs/cifs/smb2pdu.h   |   2 +
>  fs/cifs/smb2proto.h |   5 +++
>  3 files changed, 80 insertions(+), 35 deletions(-)
>
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index ed77f94dbf1d..df903931590e 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -4214,56 +4214,36 @@ num_entries(char *bufstart, char *end_of_buf, char **lastentry, size_t size)
>  /*
>   * Readdir/FindFirst
>   */
> -int
> -SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
> -                    u64 persistent_fid, u64 volatile_fid, int index,
> -                    struct cifs_search_info *srch_inf)
> +int SMB2_query_directory_init(const unsigned int xid,
> +                             struct cifs_tcon *tcon, struct smb_rqst *rqst,
> +                             u64 persistent_fid, u64 volatile_fid,
> +                             int index, int info_level)
>  {
> -       struct smb_rqst rqst;
> +       struct TCP_Server_Info *server = tcon->ses->server;
>         struct smb2_query_directory_req *req;
> -       struct smb2_query_directory_rsp *rsp = NULL;
> -       struct kvec iov[2];
> -       struct kvec rsp_iov;
> -       int rc = 0;
> -       int len;
> -       int resp_buftype = CIFS_NO_BUFFER;
>         unsigned char *bufptr;
> -       struct TCP_Server_Info *server;
> -       struct cifs_ses *ses = tcon->ses;
>         __le16 asteriks = cpu_to_le16('*');
> -       char *end_of_smb;
>         unsigned int output_size = CIFSMaxBufSize;

I think we need to account for compound responses here. The response
buffer size is MAX_SMB2_HDR_SIZE + CIFSMaxBufSize, where
MAX_SMB2_HDR_SIZE is 52 transform hdr + 64 hdr + 88 create rsp. While
output_size being CIFSMaxBufSize worked for non-compounded query
directory responses it may not fit into buffer for compounded ones
when encryption is used.

It seem like we need to set it to CIFSMaxBufSize -
MAX_SMB2_CREATE_RESPONSE_SIZE - MAX_SMB2_CLOSE_RESPONSE_SIZE like to
do in smb2_query_eas().

I found other occurrences of the similar issue in smb2_query_symlink()
and smb2_ioctl_query_info(): SMB2_ioctl_init() should use
CIFSMaxBufSize - MAX_SMB2_CREATE_RESPONSE_SIZE -
MAX_SMB2_CLOSE_RESPONSE_SIZE too instead of CIFSMaxBufSize. Could you
fix those together with this one?


> -       size_t info_buf_size;
> -       int flags = 0;
>         unsigned int total_len;
> -
> -       if (ses && (ses->server))
> -               server = ses->server;
> -       else
> -               return -EIO;
> +       struct kvec *iov = rqst->rq_iov;
> +       int len, rc;
>
>         rc = smb2_plain_req_init(SMB2_QUERY_DIRECTORY, tcon, (void **) &req,
>                              &total_len);
>         if (rc)
>                 return rc;
>
> -       if (smb3_encryption_required(tcon))
> -               flags |= CIFS_TRANSFORM_REQ;
> -
> -       switch (srch_inf->info_level) {
> +       switch (info_level) {
>         case SMB_FIND_FILE_DIRECTORY_INFO:
>                 req->FileInformationClass = FILE_DIRECTORY_INFORMATION;
> -               info_buf_size = sizeof(FILE_DIRECTORY_INFO) - 1;
>                 break;
>         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
>                 req->FileInformationClass = FILEID_FULL_DIRECTORY_INFORMATION;
> -               info_buf_size = sizeof(SEARCH_ID_FULL_DIR_INFO) - 1;
>                 break;
>         default:
>                 cifs_tcon_dbg(VFS, "info level %u isn't supported\n",
> -                        srch_inf->info_level);
> -               rc = -EINVAL;
> -               goto qdir_exit;
> +                       info_level);
> +               return -EINVAL;
>         }
>
>         req->FileIndex = cpu_to_le32(index);
> @@ -4292,15 +4272,56 @@ SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
>         iov[1].iov_base = (char *)(req->Buffer);
>         iov[1].iov_len = len;
>
> +       trace_smb3_query_dir_enter(xid, persistent_fid, tcon->tid,
> +                       tcon->ses->Suid, index, output_size);
> +
> +       return 0;
> +}
> +
> +void SMB2_query_directory_free(struct smb_rqst *rqst)
> +{
> +       if (rqst && rqst->rq_iov) {
> +               cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
> +       }
> +}
> +
> +int
> +SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
> +                    u64 persistent_fid, u64 volatile_fid, int index,
> +                    struct cifs_search_info *srch_inf)
> +{
> +       struct smb_rqst rqst;
> +       struct kvec iov[SMB2_QUERY_DIRECTORY_IOV_SIZE];
> +       struct smb2_query_directory_rsp *rsp = NULL;
> +       int resp_buftype = CIFS_NO_BUFFER;
> +       struct kvec rsp_iov;
> +       int rc = 0;
> +       struct TCP_Server_Info *server;
> +       struct cifs_ses *ses = tcon->ses;
> +       char *end_of_smb;
> +       size_t info_buf_size;
> +       int flags = 0;
> +
> +       if (ses && (ses->server))
> +               server = ses->server;
> +       else
> +               return -EIO;
> +
> +       if (smb3_encryption_required(tcon))
> +               flags |= CIFS_TRANSFORM_REQ;
> +
>         memset(&rqst, 0, sizeof(struct smb_rqst));
> +       memset(&iov, 0, sizeof(iov));
>         rqst.rq_iov = iov;
> -       rqst.rq_nvec = 2;
> +       rqst.rq_nvec = SMB2_QUERY_DIRECTORY_IOV_SIZE;
>
> -       trace_smb3_query_dir_enter(xid, persistent_fid, tcon->tid,
> -                       tcon->ses->Suid, index, output_size);
> +       rc = SMB2_query_directory_init(xid, tcon, &rqst, persistent_fid,
> +                                      volatile_fid, index,
> +                                      srch_inf->info_level);
> +       if (rc)
> +               goto qdir_exit;
>
>         rc = cifs_send_recv(xid, ses, &rqst, &resp_buftype, flags, &rsp_iov);
> -       cifs_small_buf_release(req);
>         rsp = (struct smb2_query_directory_rsp *)rsp_iov.iov_base;
>
>         if (rc) {
> @@ -4318,6 +4339,20 @@ SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
>                 goto qdir_exit;
>         }
>
> +       switch (srch_inf->info_level) {
> +       case SMB_FIND_FILE_DIRECTORY_INFO:
> +               info_buf_size = sizeof(FILE_DIRECTORY_INFO) - 1;
> +               break;
> +       case SMB_FIND_FILE_ID_FULL_DIR_INFO:
> +               info_buf_size = sizeof(SEARCH_ID_FULL_DIR_INFO) - 1;
> +               break;
> +       default:
> +               cifs_tcon_dbg(VFS, "info level %u isn't supported\n",
> +                        srch_inf->info_level);
> +               rc = -EINVAL;
> +               goto qdir_exit;
> +       }
> +
>         rc = smb2_validate_iov(le16_to_cpu(rsp->OutputBufferOffset),
>                                le32_to_cpu(rsp->OutputBufferLength), &rsp_iov,
>                                info_buf_size);
> @@ -4353,11 +4388,14 @@ SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
>         else
>                 cifs_tcon_dbg(VFS, "illegal search buffer type\n");
>
> +       rsp = NULL;

minor: the subsequent patch removes this assignment, probably better
to not do it here.

> +       resp_buftype = CIFS_NO_BUFFER;
> +
>         trace_smb3_query_dir_done(xid, persistent_fid, tcon->tid,
>                         tcon->ses->Suid, index, srch_inf->entries_in_buffer);
> -       return rc;
>
>  qdir_exit:
> +       SMB2_query_directory_free(&rqst);
>         free_rsp_buf(resp_buftype, rsp);
>         return rc;
>  }
> diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
> index f264e1d36fe1..caf323be0d7f 100644
> --- a/fs/cifs/smb2pdu.h
> +++ b/fs/cifs/smb2pdu.h
> @@ -1272,6 +1272,8 @@ struct smb2_echo_rsp {
>  #define SMB2_INDEX_SPECIFIED           0x04
>  #define SMB2_REOPEN                    0x10
>
> +#define SMB2_QUERY_DIRECTORY_IOV_SIZE 2
> +
>  struct smb2_query_directory_req {
>         struct smb2_sync_hdr sync_hdr;
>         __le16 StructureSize; /* Must be 33 */
> diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
> index d21a5fcc8d06..ba48ce9af620 100644
> --- a/fs/cifs/smb2proto.h
> +++ b/fs/cifs/smb2proto.h
> @@ -194,6 +194,11 @@ extern int SMB2_echo(struct TCP_Server_Info *server);
>  extern int SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
>                                 u64 persistent_fid, u64 volatile_fid, int index,
>                                 struct cifs_search_info *srch_inf);
> +extern int SMB2_query_directory_init(unsigned int xid, struct cifs_tcon *tcon,
> +                                    struct smb_rqst *rqst,
> +                                    u64 persistent_fid, u64 volatile_fid,
> +                                    int index, int info_level);
> +extern void SMB2_query_directory_free(struct smb_rqst *rqst);
>  extern int SMB2_set_eof(const unsigned int xid, struct cifs_tcon *tcon,
>                         u64 persistent_fid, u64 volatile_fid, u32 pid,
>                         __le64 *eof);
> --
> 2.13.6
>

Other than the note about buffer sizes above the series looks good at
the first glance.

--
Best regards,
Pavel Shilovsky
ronnie sahlberg Jan. 8, 2020, 3:09 a.m. UTC | #2
Thanks,

I have resent it after addressing your concerns.
I added an extra patch to fix the two places calling smb2_ioctl_init()
that were unrelated to opendir/readdir

regards
ronnie sahlberg

On Tue, Dec 24, 2019 at 9:50 AM Pavel Shilovsky <piastryyy@gmail.com> wrote:
>
> ср, 4 дек. 2019 г. в 14:54, Ronnie Sahlberg <lsahlber@redhat.com>:
> >
> > Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
> > ---
> >  fs/cifs/smb2pdu.c   | 108 +++++++++++++++++++++++++++++++++++-----------------
> >  fs/cifs/smb2pdu.h   |   2 +
> >  fs/cifs/smb2proto.h |   5 +++
> >  3 files changed, 80 insertions(+), 35 deletions(-)
> >
> > diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> > index ed77f94dbf1d..df903931590e 100644
> > --- a/fs/cifs/smb2pdu.c
> > +++ b/fs/cifs/smb2pdu.c
> > @@ -4214,56 +4214,36 @@ num_entries(char *bufstart, char *end_of_buf, char **lastentry, size_t size)
> >  /*
> >   * Readdir/FindFirst
> >   */
> > -int
> > -SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
> > -                    u64 persistent_fid, u64 volatile_fid, int index,
> > -                    struct cifs_search_info *srch_inf)
> > +int SMB2_query_directory_init(const unsigned int xid,
> > +                             struct cifs_tcon *tcon, struct smb_rqst *rqst,
> > +                             u64 persistent_fid, u64 volatile_fid,
> > +                             int index, int info_level)
> >  {
> > -       struct smb_rqst rqst;
> > +       struct TCP_Server_Info *server = tcon->ses->server;
> >         struct smb2_query_directory_req *req;
> > -       struct smb2_query_directory_rsp *rsp = NULL;
> > -       struct kvec iov[2];
> > -       struct kvec rsp_iov;
> > -       int rc = 0;
> > -       int len;
> > -       int resp_buftype = CIFS_NO_BUFFER;
> >         unsigned char *bufptr;
> > -       struct TCP_Server_Info *server;
> > -       struct cifs_ses *ses = tcon->ses;
> >         __le16 asteriks = cpu_to_le16('*');
> > -       char *end_of_smb;
> >         unsigned int output_size = CIFSMaxBufSize;
>
> I think we need to account for compound responses here. The response
> buffer size is MAX_SMB2_HDR_SIZE + CIFSMaxBufSize, where
> MAX_SMB2_HDR_SIZE is 52 transform hdr + 64 hdr + 88 create rsp. While
> output_size being CIFSMaxBufSize worked for non-compounded query
> directory responses it may not fit into buffer for compounded ones
> when encryption is used.
>
> It seem like we need to set it to CIFSMaxBufSize -
> MAX_SMB2_CREATE_RESPONSE_SIZE - MAX_SMB2_CLOSE_RESPONSE_SIZE like to
> do in smb2_query_eas().
>
> I found other occurrences of the similar issue in smb2_query_symlink()
> and smb2_ioctl_query_info(): SMB2_ioctl_init() should use
> CIFSMaxBufSize - MAX_SMB2_CREATE_RESPONSE_SIZE -
> MAX_SMB2_CLOSE_RESPONSE_SIZE too instead of CIFSMaxBufSize. Could you
> fix those together with this one?
>
>
> > -       size_t info_buf_size;
> > -       int flags = 0;
> >         unsigned int total_len;
> > -
> > -       if (ses && (ses->server))
> > -               server = ses->server;
> > -       else
> > -               return -EIO;
> > +       struct kvec *iov = rqst->rq_iov;
> > +       int len, rc;
> >
> >         rc = smb2_plain_req_init(SMB2_QUERY_DIRECTORY, tcon, (void **) &req,
> >                              &total_len);
> >         if (rc)
> >                 return rc;
> >
> > -       if (smb3_encryption_required(tcon))
> > -               flags |= CIFS_TRANSFORM_REQ;
> > -
> > -       switch (srch_inf->info_level) {
> > +       switch (info_level) {
> >         case SMB_FIND_FILE_DIRECTORY_INFO:
> >                 req->FileInformationClass = FILE_DIRECTORY_INFORMATION;
> > -               info_buf_size = sizeof(FILE_DIRECTORY_INFO) - 1;
> >                 break;
> >         case SMB_FIND_FILE_ID_FULL_DIR_INFO:
> >                 req->FileInformationClass = FILEID_FULL_DIRECTORY_INFORMATION;
> > -               info_buf_size = sizeof(SEARCH_ID_FULL_DIR_INFO) - 1;
> >                 break;
> >         default:
> >                 cifs_tcon_dbg(VFS, "info level %u isn't supported\n",
> > -                        srch_inf->info_level);
> > -               rc = -EINVAL;
> > -               goto qdir_exit;
> > +                       info_level);
> > +               return -EINVAL;
> >         }
> >
> >         req->FileIndex = cpu_to_le32(index);
> > @@ -4292,15 +4272,56 @@ SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
> >         iov[1].iov_base = (char *)(req->Buffer);
> >         iov[1].iov_len = len;
> >
> > +       trace_smb3_query_dir_enter(xid, persistent_fid, tcon->tid,
> > +                       tcon->ses->Suid, index, output_size);
> > +
> > +       return 0;
> > +}
> > +
> > +void SMB2_query_directory_free(struct smb_rqst *rqst)
> > +{
> > +       if (rqst && rqst->rq_iov) {
> > +               cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
> > +       }
> > +}
> > +
> > +int
> > +SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
> > +                    u64 persistent_fid, u64 volatile_fid, int index,
> > +                    struct cifs_search_info *srch_inf)
> > +{
> > +       struct smb_rqst rqst;
> > +       struct kvec iov[SMB2_QUERY_DIRECTORY_IOV_SIZE];
> > +       struct smb2_query_directory_rsp *rsp = NULL;
> > +       int resp_buftype = CIFS_NO_BUFFER;
> > +       struct kvec rsp_iov;
> > +       int rc = 0;
> > +       struct TCP_Server_Info *server;
> > +       struct cifs_ses *ses = tcon->ses;
> > +       char *end_of_smb;
> > +       size_t info_buf_size;
> > +       int flags = 0;
> > +
> > +       if (ses && (ses->server))
> > +               server = ses->server;
> > +       else
> > +               return -EIO;
> > +
> > +       if (smb3_encryption_required(tcon))
> > +               flags |= CIFS_TRANSFORM_REQ;
> > +
> >         memset(&rqst, 0, sizeof(struct smb_rqst));
> > +       memset(&iov, 0, sizeof(iov));
> >         rqst.rq_iov = iov;
> > -       rqst.rq_nvec = 2;
> > +       rqst.rq_nvec = SMB2_QUERY_DIRECTORY_IOV_SIZE;
> >
> > -       trace_smb3_query_dir_enter(xid, persistent_fid, tcon->tid,
> > -                       tcon->ses->Suid, index, output_size);
> > +       rc = SMB2_query_directory_init(xid, tcon, &rqst, persistent_fid,
> > +                                      volatile_fid, index,
> > +                                      srch_inf->info_level);
> > +       if (rc)
> > +               goto qdir_exit;
> >
> >         rc = cifs_send_recv(xid, ses, &rqst, &resp_buftype, flags, &rsp_iov);
> > -       cifs_small_buf_release(req);
> >         rsp = (struct smb2_query_directory_rsp *)rsp_iov.iov_base;
> >
> >         if (rc) {
> > @@ -4318,6 +4339,20 @@ SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
> >                 goto qdir_exit;
> >         }
> >
> > +       switch (srch_inf->info_level) {
> > +       case SMB_FIND_FILE_DIRECTORY_INFO:
> > +               info_buf_size = sizeof(FILE_DIRECTORY_INFO) - 1;
> > +               break;
> > +       case SMB_FIND_FILE_ID_FULL_DIR_INFO:
> > +               info_buf_size = sizeof(SEARCH_ID_FULL_DIR_INFO) - 1;
> > +               break;
> > +       default:
> > +               cifs_tcon_dbg(VFS, "info level %u isn't supported\n",
> > +                        srch_inf->info_level);
> > +               rc = -EINVAL;
> > +               goto qdir_exit;
> > +       }
> > +
> >         rc = smb2_validate_iov(le16_to_cpu(rsp->OutputBufferOffset),
> >                                le32_to_cpu(rsp->OutputBufferLength), &rsp_iov,
> >                                info_buf_size);
> > @@ -4353,11 +4388,14 @@ SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
> >         else
> >                 cifs_tcon_dbg(VFS, "illegal search buffer type\n");
> >
> > +       rsp = NULL;
>
> minor: the subsequent patch removes this assignment, probably better
> to not do it here.
>
> > +       resp_buftype = CIFS_NO_BUFFER;
> > +
> >         trace_smb3_query_dir_done(xid, persistent_fid, tcon->tid,
> >                         tcon->ses->Suid, index, srch_inf->entries_in_buffer);
> > -       return rc;
> >
> >  qdir_exit:
> > +       SMB2_query_directory_free(&rqst);
> >         free_rsp_buf(resp_buftype, rsp);
> >         return rc;
> >  }
> > diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
> > index f264e1d36fe1..caf323be0d7f 100644
> > --- a/fs/cifs/smb2pdu.h
> > +++ b/fs/cifs/smb2pdu.h
> > @@ -1272,6 +1272,8 @@ struct smb2_echo_rsp {
> >  #define SMB2_INDEX_SPECIFIED           0x04
> >  #define SMB2_REOPEN                    0x10
> >
> > +#define SMB2_QUERY_DIRECTORY_IOV_SIZE 2
> > +
> >  struct smb2_query_directory_req {
> >         struct smb2_sync_hdr sync_hdr;
> >         __le16 StructureSize; /* Must be 33 */
> > diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
> > index d21a5fcc8d06..ba48ce9af620 100644
> > --- a/fs/cifs/smb2proto.h
> > +++ b/fs/cifs/smb2proto.h
> > @@ -194,6 +194,11 @@ extern int SMB2_echo(struct TCP_Server_Info *server);
> >  extern int SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
> >                                 u64 persistent_fid, u64 volatile_fid, int index,
> >                                 struct cifs_search_info *srch_inf);
> > +extern int SMB2_query_directory_init(unsigned int xid, struct cifs_tcon *tcon,
> > +                                    struct smb_rqst *rqst,
> > +                                    u64 persistent_fid, u64 volatile_fid,
> > +                                    int index, int info_level);
> > +extern void SMB2_query_directory_free(struct smb_rqst *rqst);
> >  extern int SMB2_set_eof(const unsigned int xid, struct cifs_tcon *tcon,
> >                         u64 persistent_fid, u64 volatile_fid, u32 pid,
> >                         __le64 *eof);
> > --
> > 2.13.6
> >
>
> Other than the note about buffer sizes above the series looks good at
> the first glance.
>
> --
> Best regards,
> Pavel Shilovsky
diff mbox series

Patch

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index ed77f94dbf1d..df903931590e 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -4214,56 +4214,36 @@  num_entries(char *bufstart, char *end_of_buf, char **lastentry, size_t size)
 /*
  * Readdir/FindFirst
  */
-int
-SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
-		     u64 persistent_fid, u64 volatile_fid, int index,
-		     struct cifs_search_info *srch_inf)
+int SMB2_query_directory_init(const unsigned int xid,
+			      struct cifs_tcon *tcon, struct smb_rqst *rqst,
+			      u64 persistent_fid, u64 volatile_fid,
+			      int index, int info_level)
 {
-	struct smb_rqst rqst;
+	struct TCP_Server_Info *server = tcon->ses->server;
 	struct smb2_query_directory_req *req;
-	struct smb2_query_directory_rsp *rsp = NULL;
-	struct kvec iov[2];
-	struct kvec rsp_iov;
-	int rc = 0;
-	int len;
-	int resp_buftype = CIFS_NO_BUFFER;
 	unsigned char *bufptr;
-	struct TCP_Server_Info *server;
-	struct cifs_ses *ses = tcon->ses;
 	__le16 asteriks = cpu_to_le16('*');
-	char *end_of_smb;
 	unsigned int output_size = CIFSMaxBufSize;
-	size_t info_buf_size;
-	int flags = 0;
 	unsigned int total_len;
-
-	if (ses && (ses->server))
-		server = ses->server;
-	else
-		return -EIO;
+	struct kvec *iov = rqst->rq_iov;
+	int len, rc;
 
 	rc = smb2_plain_req_init(SMB2_QUERY_DIRECTORY, tcon, (void **) &req,
 			     &total_len);
 	if (rc)
 		return rc;
 
-	if (smb3_encryption_required(tcon))
-		flags |= CIFS_TRANSFORM_REQ;
-
-	switch (srch_inf->info_level) {
+	switch (info_level) {
 	case SMB_FIND_FILE_DIRECTORY_INFO:
 		req->FileInformationClass = FILE_DIRECTORY_INFORMATION;
-		info_buf_size = sizeof(FILE_DIRECTORY_INFO) - 1;
 		break;
 	case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 		req->FileInformationClass = FILEID_FULL_DIRECTORY_INFORMATION;
-		info_buf_size = sizeof(SEARCH_ID_FULL_DIR_INFO) - 1;
 		break;
 	default:
 		cifs_tcon_dbg(VFS, "info level %u isn't supported\n",
-			 srch_inf->info_level);
-		rc = -EINVAL;
-		goto qdir_exit;
+			info_level);
+		return -EINVAL;
 	}
 
 	req->FileIndex = cpu_to_le32(index);
@@ -4292,15 +4272,56 @@  SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
 	iov[1].iov_base = (char *)(req->Buffer);
 	iov[1].iov_len = len;
 
+	trace_smb3_query_dir_enter(xid, persistent_fid, tcon->tid,
+			tcon->ses->Suid, index, output_size);
+
+	return 0;
+}
+
+void SMB2_query_directory_free(struct smb_rqst *rqst)
+{
+	if (rqst && rqst->rq_iov) {
+		cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
+	}
+}
+
+int
+SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
+		     u64 persistent_fid, u64 volatile_fid, int index,
+		     struct cifs_search_info *srch_inf)
+{
+	struct smb_rqst rqst;
+	struct kvec iov[SMB2_QUERY_DIRECTORY_IOV_SIZE];
+	struct smb2_query_directory_rsp *rsp = NULL;
+	int resp_buftype = CIFS_NO_BUFFER;
+	struct kvec rsp_iov;
+	int rc = 0;
+	struct TCP_Server_Info *server;
+	struct cifs_ses *ses = tcon->ses;
+	char *end_of_smb;
+	size_t info_buf_size;
+	int flags = 0;
+
+	if (ses && (ses->server))
+		server = ses->server;
+	else
+		return -EIO;
+
+	if (smb3_encryption_required(tcon))
+		flags |= CIFS_TRANSFORM_REQ;
+
 	memset(&rqst, 0, sizeof(struct smb_rqst));
+	memset(&iov, 0, sizeof(iov));
 	rqst.rq_iov = iov;
-	rqst.rq_nvec = 2;
+	rqst.rq_nvec = SMB2_QUERY_DIRECTORY_IOV_SIZE;
 
-	trace_smb3_query_dir_enter(xid, persistent_fid, tcon->tid,
-			tcon->ses->Suid, index, output_size);
+	rc = SMB2_query_directory_init(xid, tcon, &rqst, persistent_fid,
+				       volatile_fid, index,
+				       srch_inf->info_level);
+	if (rc)
+		goto qdir_exit;
 
 	rc = cifs_send_recv(xid, ses, &rqst, &resp_buftype, flags, &rsp_iov);
-	cifs_small_buf_release(req);
 	rsp = (struct smb2_query_directory_rsp *)rsp_iov.iov_base;
 
 	if (rc) {
@@ -4318,6 +4339,20 @@  SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
 		goto qdir_exit;
 	}
 
+	switch (srch_inf->info_level) {
+	case SMB_FIND_FILE_DIRECTORY_INFO:
+		info_buf_size = sizeof(FILE_DIRECTORY_INFO) - 1;
+		break;
+	case SMB_FIND_FILE_ID_FULL_DIR_INFO:
+		info_buf_size = sizeof(SEARCH_ID_FULL_DIR_INFO) - 1;
+		break;
+	default:
+		cifs_tcon_dbg(VFS, "info level %u isn't supported\n",
+			 srch_inf->info_level);
+		rc = -EINVAL;
+		goto qdir_exit;
+	}
+
 	rc = smb2_validate_iov(le16_to_cpu(rsp->OutputBufferOffset),
 			       le32_to_cpu(rsp->OutputBufferLength), &rsp_iov,
 			       info_buf_size);
@@ -4353,11 +4388,14 @@  SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
 	else
 		cifs_tcon_dbg(VFS, "illegal search buffer type\n");
 
+	rsp = NULL;
+	resp_buftype = CIFS_NO_BUFFER;
+
 	trace_smb3_query_dir_done(xid, persistent_fid, tcon->tid,
 			tcon->ses->Suid, index, srch_inf->entries_in_buffer);
-	return rc;
 
 qdir_exit:
+	SMB2_query_directory_free(&rqst);
 	free_rsp_buf(resp_buftype, rsp);
 	return rc;
 }
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index f264e1d36fe1..caf323be0d7f 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -1272,6 +1272,8 @@  struct smb2_echo_rsp {
 #define SMB2_INDEX_SPECIFIED		0x04
 #define SMB2_REOPEN			0x10
 
+#define SMB2_QUERY_DIRECTORY_IOV_SIZE 2
+
 struct smb2_query_directory_req {
 	struct smb2_sync_hdr sync_hdr;
 	__le16 StructureSize; /* Must be 33 */
diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
index d21a5fcc8d06..ba48ce9af620 100644
--- a/fs/cifs/smb2proto.h
+++ b/fs/cifs/smb2proto.h
@@ -194,6 +194,11 @@  extern int SMB2_echo(struct TCP_Server_Info *server);
 extern int SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
 				u64 persistent_fid, u64 volatile_fid, int index,
 				struct cifs_search_info *srch_inf);
+extern int SMB2_query_directory_init(unsigned int xid, struct cifs_tcon *tcon,
+				     struct smb_rqst *rqst,
+				     u64 persistent_fid, u64 volatile_fid,
+				     int index, int info_level);
+extern void SMB2_query_directory_free(struct smb_rqst *rqst);
 extern int SMB2_set_eof(const unsigned int xid, struct cifs_tcon *tcon,
 			u64 persistent_fid, u64 volatile_fid, u32 pid,
 			__le64 *eof);