On 2/19/21 1:32 PM, Bodo Stroesser wrote:

On 17.02.21 21:28, Mike Christie wrote:

quoted

tcm_loop could be used like a normal block device, so we can't use
GFP_KERNEL. This adds a gfp_t arg to target_cmd_init_cdb and covnerts
the users. For every driver but loop I kept GFP_KERNEL. For loop and
xcopy I switched to GFP_NOIO.

In the patch below for xcopy GFP_KERNEL is inserted.

The code is correct. I'll fix the commit message. I thought it needed
to be NOIO when I first made the patch. I later realized we would never
hit an issue since it's outside the main IO path that would get executed if
WRITEs were done to satisfy the GFP_KERNEL alloc in the xcopy code.

quoted

This will also be useful in the later patches where loop needs to
do target_submit_prep from interrupt context to get a ref to the
se_device, and so it will need to use GFP_ATOMIC.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Laurence Oberman <redacted>
---
  drivers/infiniband/ulp/srpt/ib_srpt.c  |  3 ++-
  drivers/scsi/qla2xxx/tcm_qla2xxx.c     |  3 ++-
  drivers/target/iscsi/iscsi_target.c    |  3 ++-
  drivers/target/loopback/tcm_loop.c     |  3 ++-
  drivers/target/target_core_transport.c | 14 ++++++++------
  drivers/target/target_core_xcopy.c     |  2 +-
  drivers/target/tcm_fc/tfc_cmd.c        |  2 +-
  drivers/vhost/scsi.c                   |  2 +-
  drivers/xen/xen-scsiback.c             |  2 +-
  include/target/target_core_fabric.h    |  5 +++--
  10 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 87741e0b4bca..51c386a215f5 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c

@@ -1537,7 +1537,8 @@ static void srpt_handle_cmd(struct srpt_rdma_ch *ch,

          goto busy;
      }
  -    if (target_submit_prep(cmd, srp_cmd->cdb, sg, sg_cnt, NULL, 0, NULL, 0))
+    if (target_submit_prep(cmd, srp_cmd->cdb, sg, sg_cnt, NULL, 0, NULL, 0,
+                   GFP_KERNEL))
          return;
        target_submit(cmd);

diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
index 56394d901791..12a2265eb2de 100644
--- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
+++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c

@@ -492,7 +492,8 @@ static int tcm_qla2xxx_handle_cmd(scsi_qla_host_t *vha, struct qla_tgt_cmd *cmd,

      if (rc)
          return rc;
  -    if (target_submit_prep(se_cmd, cdb, NULL, 0, NULL, 0, NULL, 0))
+    if (target_submit_prep(se_cmd, cdb, NULL, 0, NULL, 0, NULL, 0,
+                   GFP_KERNEL))
          return 0;
        target_submit(se_cmd);

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index f2107705f2ea..566adfde1661 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c

@@ -1166,7 +1166,8 @@ int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,

        target_get_sess_cmd(&cmd->se_cmd, true);
  -    cmd->sense_reason = target_cmd_init_cdb(&cmd->se_cmd, hdr->cdb);
+    cmd->sense_reason = target_cmd_init_cdb(&cmd->se_cmd, hdr->cdb,
+                        GFP_KERNEL);
      if (cmd->sense_reason) {
          if (cmd->sense_reason == TCM_OUT_OF_RESOURCES) {
              return iscsit_add_reject_cmd(cmd,

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 461f4125fcab..677e4b8f0642 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c

@@ -156,7 +156,8 @@ static void tcm_loop_submission_work(struct work_struct *work)

        if (target_submit_prep(se_cmd, sc->cmnd, scsi_sglist(sc),
                     scsi_sg_count(sc), sgl_bidi, sgl_bidi_count,
-                   scsi_prot_sglist(sc), scsi_prot_sg_count(sc)))
+                   scsi_prot_sglist(sc), scsi_prot_sg_count(sc),
+                   GFP_NOIO))
          return;
        target_submit(se_cmd);

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 1f35cce6e92b..6c88ca832da6 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c

@@ -1427,7 +1427,7 @@ transport_check_alloc_task_attr(struct se_cmd *cmd)

  }
    sense_reason_t
-target_cmd_init_cdb(struct se_cmd *cmd, unsigned char *cdb)
+target_cmd_init_cdb(struct se_cmd *cmd, unsigned char *cdb, gfp_t gfp)
  {
      sense_reason_t ret;
  @@ -1448,8 +1448,7 @@ target_cmd_init_cdb(struct se_cmd *cmd, unsigned char *cdb)
       * setup the pointer from __t_task_cdb to t_task_cdb.
       */
      if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
-        cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
-                        GFP_KERNEL);
+        cmd->t_task_cdb = kzalloc(scsi_command_size(cdb), gfp);
          if (!cmd->t_task_cdb) {
              pr_err("Unable to allocate cmd->t_task_cdb"
                  " %u > sizeof(cmd->__t_task_cdb): %lu ops\n",

@@ -1638,6 +1637,7 @@ EXPORT_SYMBOL_GPL(target_init_cmd);

   * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
   * @sgl_prot: struct scatterlist memory protection information
   * @sgl_prot_count: scatterlist count for protection information
+ * @gfp_t: gfp allocation type
   *
   * Returns:
   *    - less than zero to signal failure.

@@ -1648,11 +1648,12 @@ EXPORT_SYMBOL_GPL(target_init_cmd);

  int target_submit_prep(struct se_cmd *se_cmd, unsigned char *cdb,
                 struct scatterlist *sgl, u32 sgl_count,
                 struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
-               struct scatterlist *sgl_prot, u32 sgl_prot_count)
+               struct scatterlist *sgl_prot, u32 sgl_prot_count,
+               gfp_t gfp)
  {
      sense_reason_t rc;
  -    rc = target_cmd_init_cdb(se_cmd, cdb);
+    rc = target_cmd_init_cdb(se_cmd, cdb, gfp);
      if (rc)
          goto send_cc_direct;
  @@ -1788,7 +1789,8 @@ void target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
      if (rc)
          return;
  -    if (target_submit_prep(se_cmd, cdb, NULL, 0, NULL, 0, NULL, 0))
+    if (target_submit_prep(se_cmd, cdb, NULL, 0, NULL, 0, NULL, 0,
+                   GFP_KERNEL))
          return;
        target_submit(se_cmd);

diff --git a/drivers/target/target_core_xcopy.c b/drivers/target/target_core_xcopy.c
index e86cc6135587..d31ed071cb08 100644
--- a/drivers/target/target_core_xcopy.c
+++ b/drivers/target/target_core_xcopy.c

@@ -554,7 +554,7 @@ static int target_xcopy_setup_pt_cmd(

      }
      cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
  -    if (target_cmd_init_cdb(cmd, cdb))
+    if (target_cmd_init_cdb(cmd, cdb, GFP_KERNEL))
          return -EINVAL;
        cmd->tag = 0;

diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c
index 1376501ee3d0..410b723f9d79 100644
--- a/drivers/target/tcm_fc/tfc_cmd.c
+++ b/drivers/target/tcm_fc/tfc_cmd.c

@@ -555,7 +555,7 @@ static void ft_send_work(struct work_struct *work)

          goto err;
        if (target_submit_prep(&cmd->se_cmd, fcp->fc_cdb, NULL, 0, NULL, 0,
-                   NULL, 0))
+                   NULL, 0, GFP_KERNEL))
          return;
        target_submit(&cmd->se_cmd);

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 76508d408bb3..93f5631b469c 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c

@@ -811,7 +811,7 @@ static void vhost_scsi_submission_work(struct work_struct *work)

        if (target_submit_prep(se_cmd, cmd->tvc_cdb, sg_ptr,
                     cmd->tvc_sgl_count, NULL, 0, sg_prot_ptr,
-                   cmd->tvc_prot_sgl_count))
+                   cmd->tvc_prot_sgl_count, GFP_KERNEL))
          return;
        target_submit(se_cmd);

diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 7bf9a6bede6d..eb3d8e35cbcd 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c

@@ -368,7 +368,7 @@ static void scsiback_cmd_exec(struct vscsibk_pend *pending_req)

              pending_req->sc_data_direction, TARGET_SCF_ACK_KREF);
        if (target_submit_prep(se_cmd, pending_req->cmnd, pending_req->sgl,
-                   pending_req->n_sg, NULL, 0, NULL, 0))
+                   pending_req->n_sg, NULL, 0, NULL, 0, GFP_KERNEL))
          return;
        target_submit(se_cmd);

diff --git a/include/target/target_core_fabric.h b/include/target/target_core_fabric.h
index 86b0d4a7df92..0543ab107723 100644
--- a/include/target/target_core_fabric.h
+++ b/include/target/target_core_fabric.h

@@ -157,10 +157,11 @@ int    target_init_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,

  int    target_submit_prep(struct se_cmd *se_cmd, unsigned char *cdb,
          struct scatterlist *sgl, u32 sgl_count,
          struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
-        struct scatterlist *sgl_prot, u32 sgl_prot_count);
+        struct scatterlist *sgl_prot, u32 sgl_prot_count, gfp_t gfp);
  void    target_submit(struct se_cmd *se_cmd);
  sense_reason_t transport_lookup_cmd_lun(struct se_cmd *);
-sense_reason_t target_cmd_init_cdb(struct se_cmd *, unsigned char *);
+sense_reason_t target_cmd_init_cdb(struct se_cmd *se_cmd, unsigned char *cdb,
+                   gfp_t gfp);
  sense_reason_t target_cmd_parse_cdb(struct se_cmd *);
  void    target_submit_cmd(struct se_cmd *, struct se_session *, unsigned char *,
          unsigned char *, u64, u32, int, int, int);