diff options
author | Nicholas Bellinger <nab@linux-iscsi.org> | 2015-03-23 06:42:19 +0300 |
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committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2015-06-01 10:23:46 +0300 |
commit | 29a05deebf6c2e3010934fb78ee65cab3d329470 (patch) | |
tree | 5b91d971e31c45919ef212513104350877807c3c /include/target/target_core_backend.h | |
parent | d2c27f0d0b7eb18f40b9b1a0d793c8ba074e5c23 (diff) | |
download | linux-29a05deebf6c2e3010934fb78ee65cab3d329470.tar.xz |
target: Convert se_node_acl->device_list[] to RCU hlist
This patch converts se_node_acl->device_list[] table for mappedluns
to modern RCU hlist_head usage in order to support an arbitrary number
of node_acl lun mappings.
It converts transport_lookup_*_lun() fast-path code to use RCU read path
primitives when looking up se_dev_entry. It adds a new hlist_head at
se_node_acl->lun_entry_hlist for this purpose.
For transport_lookup_cmd_lun() code, it works with existing per-cpu
se_lun->lun_ref when associating se_cmd with se_lun + se_device.
Also, go ahead and update core_create_device_list_for_node() +
core_free_device_list_for_node() to use ->lun_entry_hlist.
It also converts se_dev_entry->pr_ref_count access to use modern
struct kref counting, and updates core_disable_device_list_for_node()
to kref_put() and block on se_deve->pr_comp waiting for outstanding PR
special-case PR references to drop, then invoke kfree_rcu() to wait
for the RCU grace period to complete before releasing memory.
So now that se_node_acl->lun_entry_hlist fast path access uses RCU
protected pointers, go ahead and convert remaining non-fast path
RCU updater code using ->lun_entry_lock to struct mutex to allow
callers to block while walking se_node_acl->lun_entry_hlist.
Finally drop the left-over core_clear_initiator_node_from_tpg() that
originally cleared lun_access during se_node_acl shutdown, as post
RCU conversion it now becomes duplicated logic.
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'include/target/target_core_backend.h')
-rw-r--r-- | include/target/target_core_backend.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h index 47fafec556f8..80d9e486e33e 100644 --- a/include/target/target_core_backend.h +++ b/include/target/target_core_backend.h @@ -101,7 +101,7 @@ int target_alloc_sgl(struct scatterlist **, unsigned int *, u32, bool); sense_reason_t transport_generic_map_mem_to_cmd(struct se_cmd *, struct scatterlist *, u32, struct scatterlist *, u32); -void array_free(void *array, int n); +bool target_lun_is_rdonly(struct se_cmd *); /* From target_core_configfs.c to setup default backend config_item_types */ void target_core_setup_sub_cits(struct se_subsystem_api *); |