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authorDmitry Bogdanov <d.bogdanov@yadro.com>2022-07-27 23:41:25 +0200
committerMartin K. Petersen <martin.petersen@oracle.com>2022-08-02 01:36:02 +0200
commitef4f7e4bf1dc26aaa86cf8e5a13013684139be51 (patch)
tree432760c8e0d00e319a04fefc9f386e3aa3d1e2da /drivers/target
parentscsi: target: core: Fix race during ACL removal (diff)
downloadlinux-ef4f7e4bf1dc26aaa86cf8e5a13013684139be51.tar.xz
linux-ef4f7e4bf1dc26aaa86cf8e5a13013684139be51.zip
scsi: target: core: De-RCU of se_lun and se_lun acl
se_lun and se_lun_acl are immutable pointers of struct se_dev_entry. Remove RCU usage for access to those pointers. Link: https://lore.kernel.org/r/20220727214125.19647-3-d.bogdanov@yadro.com Reviewed-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Dmitry Bogdanov <d.bogdanov@yadro.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/target')
-rw-r--r--drivers/target/target_core_alua.c3
-rw-r--r--drivers/target/target_core_device.c29
-rw-r--r--drivers/target/target_core_pr.c28
-rw-r--r--drivers/target/target_core_stat.c10
-rw-r--r--drivers/target/target_core_xcopy.c2
5 files changed, 25 insertions, 47 deletions
diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
index 58df0145e8d0..fb91423a4e2e 100644
--- a/drivers/target/target_core_alua.c
+++ b/drivers/target/target_core_alua.c
@@ -934,8 +934,7 @@ static void core_alua_queue_state_change_ua(struct t10_alua_tg_pt_gp *tg_pt_gp)
spin_lock(&lun->lun_deve_lock);
list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link) {
- lacl = rcu_dereference_check(se_deve->se_lun_acl,
- lockdep_is_held(&lun->lun_deve_lock));
+ lacl = se_deve->se_lun_acl;
/*
* spc4r37 p.242:
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 88a844ae1fd0..b7f16ee8aa0e 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -75,7 +75,7 @@ transport_lookup_cmd_lun(struct se_cmd *se_cmd)
return TCM_WRITE_PROTECTED;
}
- se_lun = rcu_dereference(deve->se_lun);
+ se_lun = deve->se_lun;
if (!percpu_ref_tryget_live(&se_lun->lun_ref)) {
se_lun = NULL;
@@ -152,7 +152,7 @@ int transport_lookup_tmr_lun(struct se_cmd *se_cmd)
rcu_read_lock();
deve = target_nacl_find_deve(nacl, se_cmd->orig_fe_lun);
if (deve) {
- se_lun = rcu_dereference(deve->se_lun);
+ se_lun = deve->se_lun;
if (!percpu_ref_tryget_live(&se_lun->lun_ref)) {
se_lun = NULL;
@@ -216,7 +216,7 @@ struct se_dev_entry *core_get_se_deve_from_rtpi(
rcu_read_lock();
hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) {
- lun = rcu_dereference(deve->se_lun);
+ lun = deve->se_lun;
if (!lun) {
pr_err("%s device entries device pointer is"
" NULL, but Initiator has access.\n",
@@ -243,11 +243,8 @@ void core_free_device_list_for_node(
struct se_dev_entry *deve;
mutex_lock(&nacl->lun_entry_mutex);
- hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) {
- struct se_lun *lun = rcu_dereference_check(deve->se_lun,
- lockdep_is_held(&nacl->lun_entry_mutex));
- core_disable_device_list_for_node(lun, deve, nacl, tpg);
- }
+ hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link)
+ core_disable_device_list_for_node(deve->se_lun, deve, nacl, tpg);
mutex_unlock(&nacl->lun_entry_mutex);
}
@@ -334,8 +331,7 @@ int core_enable_device_list_for_node(
mutex_lock(&nacl->lun_entry_mutex);
orig = target_nacl_find_deve(nacl, mapped_lun);
if (orig && orig->se_lun) {
- struct se_lun *orig_lun = rcu_dereference_check(orig->se_lun,
- lockdep_is_held(&nacl->lun_entry_mutex));
+ struct se_lun *orig_lun = orig->se_lun;
if (orig_lun != lun) {
pr_err("Existing orig->se_lun doesn't match new lun"
@@ -355,8 +351,8 @@ int core_enable_device_list_for_node(
return -EINVAL;
}
- rcu_assign_pointer(new->se_lun, lun);
- rcu_assign_pointer(new->se_lun_acl, lun_acl);
+ new->se_lun = lun;
+ new->se_lun_acl = lun_acl;
hlist_del_rcu(&orig->link);
hlist_add_head_rcu(&new->link, &nacl->lun_entry_hlist);
mutex_unlock(&nacl->lun_entry_mutex);
@@ -374,8 +370,8 @@ int core_enable_device_list_for_node(
return 0;
}
- rcu_assign_pointer(new->se_lun, lun);
- rcu_assign_pointer(new->se_lun_acl, lun_acl);
+ new->se_lun = lun;
+ new->se_lun_acl = lun_acl;
hlist_add_head_rcu(&new->link, &nacl->lun_entry_hlist);
mutex_unlock(&nacl->lun_entry_mutex);
@@ -454,10 +450,7 @@ void core_clear_lun_from_tpg(struct se_lun *lun, struct se_portal_group *tpg)
mutex_lock(&nacl->lun_entry_mutex);
hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) {
- struct se_lun *tmp_lun = rcu_dereference_check(deve->se_lun,
- lockdep_is_held(&nacl->lun_entry_mutex));
-
- if (lun != tmp_lun)
+ if (lun != deve->se_lun)
continue;
core_disable_device_list_for_node(lun, deve, nacl, tpg);
diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 3829b61b56c1..a1d67554709f 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -739,8 +739,7 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration(
if (!deve_tmp->se_lun_acl)
continue;
- lacl_tmp = rcu_dereference_check(deve_tmp->se_lun_acl,
- lockdep_is_held(&lun_tmp->lun_deve_lock));
+ lacl_tmp = deve_tmp->se_lun_acl;
nacl_tmp = lacl_tmp->se_lun_nacl;
/*
* Skip the matching struct se_node_acl that is allocated
@@ -784,8 +783,7 @@ static struct t10_pr_registration *__core_scsi3_alloc_registration(
* the original *pr_reg is processed in
* __core_scsi3_add_registration()
*/
- dest_lun = rcu_dereference_check(deve_tmp->se_lun,
- kref_read(&deve_tmp->pr_kref) != 0);
+ dest_lun = deve_tmp->se_lun;
pr_reg_atp = __core_scsi3_do_alloc_registration(dev,
nacl_tmp, dest_lun, deve_tmp,
@@ -1437,34 +1435,26 @@ static void core_scsi3_nodeacl_undepend_item(struct se_node_acl *nacl)
static int core_scsi3_lunacl_depend_item(struct se_dev_entry *se_deve)
{
- struct se_lun_acl *lun_acl;
-
/*
* For nacl->dynamic_node_acl=1
*/
- lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
- kref_read(&se_deve->pr_kref) != 0);
- if (!lun_acl)
+ if (!se_deve->se_lun_acl)
return 0;
- return target_depend_item(&lun_acl->se_lun_group.cg_item);
+ return target_depend_item(&se_deve->se_lun_acl->se_lun_group.cg_item);
}
static void core_scsi3_lunacl_undepend_item(struct se_dev_entry *se_deve)
{
- struct se_lun_acl *lun_acl;
-
/*
* For nacl->dynamic_node_acl=1
*/
- lun_acl = rcu_dereference_check(se_deve->se_lun_acl,
- kref_read(&se_deve->pr_kref) != 0);
- if (!lun_acl) {
+ if (!se_deve->se_lun_acl) {
kref_put(&se_deve->pr_kref, target_pr_kref_release);
return;
}
- target_undepend_item(&lun_acl->se_lun_group.cg_item);
+ target_undepend_item(&se_deve->se_lun_acl->se_lun_group.cg_item);
kref_put(&se_deve->pr_kref, target_pr_kref_release);
}
@@ -1751,8 +1741,7 @@ core_scsi3_decode_spec_i_port(
* and then call __core_scsi3_add_registration() in the
* 2nd loop which will never fail.
*/
- dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
- kref_read(&dest_se_deve->pr_kref) != 0);
+ dest_lun = dest_se_deve->se_lun;
dest_pr_reg = __core_scsi3_alloc_registration(cmd->se_dev,
dest_node_acl, dest_lun, dest_se_deve,
@@ -3446,8 +3435,7 @@ after_iport_check:
dest_pr_reg = __core_scsi3_locate_pr_reg(dev, dest_node_acl,
iport_ptr);
if (!dest_pr_reg) {
- struct se_lun *dest_lun = rcu_dereference_check(dest_se_deve->se_lun,
- kref_read(&dest_se_deve->pr_kref) != 0);
+ struct se_lun *dest_lun = dest_se_deve->se_lun;
spin_unlock(&dev->dev_reservation_lock);
if (core_scsi3_alloc_registration(cmd->se_dev, dest_node_acl,
diff --git a/drivers/target/target_core_stat.c b/drivers/target/target_core_stat.c
index 62d15bcc3d93..f85ee5b0fd80 100644
--- a/drivers/target/target_core_stat.c
+++ b/drivers/target/target_core_stat.c
@@ -877,7 +877,6 @@ static ssize_t target_stat_auth_dev_show(struct config_item *item,
struct se_lun_acl *lacl = auth_to_lacl(item);
struct se_node_acl *nacl = lacl->se_lun_nacl;
struct se_dev_entry *deve;
- struct se_lun *lun;
ssize_t ret;
rcu_read_lock();
@@ -886,9 +885,9 @@ static ssize_t target_stat_auth_dev_show(struct config_item *item,
rcu_read_unlock();
return -ENODEV;
}
- lun = rcu_dereference(deve->se_lun);
+
/* scsiDeviceIndex */
- ret = snprintf(page, PAGE_SIZE, "%u\n", lun->lun_index);
+ ret = snprintf(page, PAGE_SIZE, "%u\n", deve->se_lun->lun_index);
rcu_read_unlock();
return ret;
}
@@ -1217,7 +1216,6 @@ static ssize_t target_stat_iport_dev_show(struct config_item *item,
struct se_lun_acl *lacl = iport_to_lacl(item);
struct se_node_acl *nacl = lacl->se_lun_nacl;
struct se_dev_entry *deve;
- struct se_lun *lun;
ssize_t ret;
rcu_read_lock();
@@ -1226,9 +1224,9 @@ static ssize_t target_stat_iport_dev_show(struct config_item *item,
rcu_read_unlock();
return -ENODEV;
}
- lun = rcu_dereference(deve->se_lun);
+
/* scsiDeviceIndex */
- ret = snprintf(page, PAGE_SIZE, "%u\n", lun->lun_index);
+ ret = snprintf(page, PAGE_SIZE, "%u\n", deve->se_lun->lun_index);
rcu_read_unlock();
return ret;
}
diff --git a/drivers/target/target_core_xcopy.c b/drivers/target/target_core_xcopy.c
index 6bb20aa9c5bc..8713cda0c2fb 100644
--- a/drivers/target/target_core_xcopy.c
+++ b/drivers/target/target_core_xcopy.c
@@ -88,7 +88,7 @@ static int target_xcopy_locate_se_dev_e4(struct se_session *sess,
struct se_device *this_dev;
int rc;
- this_lun = rcu_dereference(deve->se_lun);
+ this_lun = deve->se_lun;
this_dev = rcu_dereference_raw(this_lun->lun_se_dev);
rc = target_xcopy_locate_se_dev_e4_iter(this_dev, dev_wwn);