From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch converts SPC emulation for REPORT_LUN + MODE_SENSE to use
RCU read path macros for se_node_acl->lun_entry_hlist[] access.
Cc: Hannes Reinecke <hare@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Sagi Grimberg <sagig@xxxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_spc.c | 28 ++++++++++++++++++----------
include/target/target_core_base.h | 1 -
2 files changed, 18 insertions(+), 11 deletions(-)
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index 5b6a0af..12cb045 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -986,6 +986,8 @@ static int spc_modesense_long_blockdesc(unsigned char *buf, u64 blocks, u32 bloc
static sense_reason_t spc_emulate_modesense(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
+ struct se_dev_entry *deve;
+ struct se_session *sess = cmd->se_sess;
char *cdb = cmd->t_task_cdb;
unsigned char buf[SE_MODE_PAGE_BUF], *rbuf;
int type = dev->transport->get_device_type(dev);
@@ -998,6 +1000,7 @@ static sense_reason_t spc_emulate_modesense(struct se_cmd *cmd)
int length = 0;
int ret;
int i;
+ bool read_only;
memset(buf, 0, SE_MODE_PAGE_BUF);
@@ -1007,10 +1010,13 @@ static sense_reason_t spc_emulate_modesense(struct se_cmd *cmd)
*/
length = ten ? 3 : 2;
+ rcu_read_lock();
+ deve = rcu_dereference(sess->se_node_acl->lun_entry_hlist[cmd->orig_fe_lun]);
+ read_only = (deve->lun_flags & TRANSPORT_LUNFLAGS_READ_ONLY);
+ rcu_read_unlock();
+
/* DEVICE-SPECIFIC PARAMETER */
- if ((cmd->se_lun->lun_access & TRANSPORT_LUNFLAGS_READ_ONLY) ||
- (cmd->se_deve &&
- (cmd->se_deve->lun_flags & TRANSPORT_LUNFLAGS_READ_ONLY)))
+ if ((cmd->se_lun->lun_access & TRANSPORT_LUNFLAGS_READ_ONLY) || read_only)
spc_modesense_write_protect(&buf[length], type);
if ((spc_check_dev_wce(dev)) &&
@@ -1225,7 +1231,7 @@ sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd)
struct se_dev_entry *deve;
struct se_session *sess = cmd->se_sess;
unsigned char *buf;
- u32 lun_count = 0, offset = 8, i;
+ u32 lun_count = 0, offset = 8, i, mapped_lun;
if (cmd->data_length < 16) {
pr_warn("REPORT LUNS allocation length %u too small\n",
@@ -1248,11 +1254,15 @@ sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd)
goto done;
}
- spin_lock_irq(&sess->se_node_acl->device_list_lock);
for (i = 0; i < TRANSPORT_MAX_LUNS_PER_TPG; i++) {
- deve = sess->se_node_acl->device_list[i];
- if (!(deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS))
+ rcu_read_lock();
+ deve = rcu_dereference(sess->se_node_acl->lun_entry_hlist[i]);
+ if (!(deve->lun_flags & TRANSPORT_LUNFLAGS_INITIATOR_ACCESS)) {
+ rcu_read_unlock();
continue;
+ }
+ mapped_lun = deve->mapped_lun;
+ rcu_read_unlock();
/*
* We determine the correct LUN LIST LENGTH even once we
* have reached the initial allocation length.
@@ -1262,11 +1272,9 @@ sense_reason_t spc_emulate_report_luns(struct se_cmd *cmd)
if ((offset + 8) > cmd->data_length)
continue;
- int_to_scsilun(deve->mapped_lun, (struct scsi_lun *)&buf[offset]);
+ int_to_scsilun(mapped_lun, (struct scsi_lun *)&buf[offset]);
offset += 8;
}
- spin_unlock_irq(&sess->se_node_acl->device_list_lock);
-
/*
* See SPC3 r07, page 159.
*/
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 06ecd7b..a826e6f 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -512,7 +512,6 @@ struct se_cmd {
struct list_head se_delayed_node;
struct list_head se_qf_node;
struct se_device *se_dev;
- struct se_dev_entry *se_deve;
struct se_lun *se_lun;
/* Only used for internal passthrough and legacy TCM fabric modules */
struct se_session *se_sess;
--
1.9.1
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