@@ -1450,6 +1450,7 @@ int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess
if (sgl_prot_count) {
se_cmd->t_prot_sg = sgl_prot;
se_cmd->t_prot_nents = sgl_prot_count;
+ se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
}
/*
@@ -2181,6 +2182,12 @@ static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
static inline void transport_free_pages(struct se_cmd *cmd)
{
+ if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
+ transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
+ cmd->t_prot_sg = NULL;
+ cmd->t_prot_nents = 0;
+ }
+
if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
/*
* Release special case READ buffer payload required for
@@ -2204,10 +2211,6 @@ static inline void transport_free_pages(struct se_cmd *cmd)
transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
cmd->t_bidi_data_sg = NULL;
cmd->t_bidi_data_nents = 0;
-
- transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
- cmd->t_prot_sg = NULL;
- cmd->t_prot_nents = 0;
}
/**
@@ -2346,6 +2349,14 @@ transport_generic_new_cmd(struct se_cmd *cmd)
int ret = 0;
bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
+ if (cmd->prot_op != TARGET_PROT_NORMAL &&
+ !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
+ ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
+ cmd->prot_length, true);
+ if (ret < 0)
+ return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+ }
+
/*
* Determine is the TCM fabric module has already allocated physical
* memory, and is directly calling transport_generic_map_mem_to_cmd()
@@ -2371,14 +2382,6 @@ transport_generic_new_cmd(struct se_cmd *cmd)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
- if (cmd->prot_op != TARGET_PROT_NORMAL) {
- ret = target_alloc_sgl(&cmd->t_prot_sg,
- &cmd->t_prot_nents,
- cmd->prot_length, true);
- if (ret < 0)
- return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
- }
-
ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
cmd->data_length, zero_flag);
if (ret < 0)
@@ -167,6 +167,7 @@ enum se_cmd_flags_table {
SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC = 0x00020000,
SCF_COMPARE_AND_WRITE = 0x00080000,
SCF_COMPARE_AND_WRITE_POST = 0x00100000,
+ SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC = 0x00200000,
};
/* struct se_dev_entry->lun_flags and struct se_lun->lun_access */
Even if the device backend is initialized with protection info is enabled, some requests don't have the protection info attached for WRITE SAME command issued by block device helpers, WRITE command with WRPROTECT=0 by SG_IO ioctl, etc. So when TCM loopback fabric module is used, se_cmd->t_prot_sg is NULL for these requests and performing WRITE_INSERT of PI using software emulation by sbc_dif_generate() causes kernel crash. To fix this, introduce SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC for se_cmd_flags, which is used to determine that se_cmd->t_prot_sg needs to be allocated or use pre-allocated protection information by scsi mid-layer. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Nicholas Bellinger <nab@linux-iscsi.org> Cc: Sagi Grimberg <sagig@mellanox.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: target-devel@vger.kernel.org Cc: linux-scsi@vger.kernel.org --- * Changes from v3: - Improve the condition in transport_generic_new_cmd() a bit drivers/target/target_core_transport.c | 27 +++++++++++++++------------ include/target/target_core_base.h | 1 + 2 files changed, 16 insertions(+), 12 deletions(-)