| Message ID | 20200510215744.21999-13-mchristi@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | target: add sysfs support | expand |
On 05/10/20 23:57, Mike Christie wrote: > This patch adds helpers to add/remove a dir per session. There is only 2 > files/dirs initially. > ... > + > +int target_sysfs_add_session(struct se_portal_group *se_tpg, > + struct se_session *se_sess) > +{ > + int ret; > + > + /* > + * Copy ACL name so we don't have to worry about mixing configfs > + * and sysfs refcounts. > + */ > + if (!se_sess->se_node_acl->dynamic_node_acl) { > + se_sess->acl_name = kstrdup(se_sess->se_node_acl->initiatorname, > + GFP_KERNEL); > + if (!se_sess->acl_name) > + return -ENOMEM; > + } > + > + ret = kobject_add(&se_sess->kobj, se_tpg->sessions_kobj, "%s-%d", > + se_sess->tpt_id->name, se_sess->sid); > + if (ret) { > + pr_err("Could not add session%d to sysfs. Error %d.\n", > + se_sess->sid, ret); > + goto free_acl_name; > + } > + > + ret = add_transport_id_attrs(se_sess); > + if (ret) > + goto del_kobj; > + > + if (se_sess->tfo->session_attrs) { > + ret = sysfs_create_group(&se_sess->kobj, > + se_sess->tfo->session_attrs); > + if (ret) > + goto rm_tpt_id_grps; > + } > + > + ret = sysfs_create_link(tcm_core_sessions_kobj, &se_sess->kobj, > + se_sess->kobj.name); I would prefer to have links named "session-%d" or "%d" only, of course with se_sess->sid as the value for '%d'. If userspace knows the session-id only, such names make it easier to find the corresponding link. > + if (ret) > + goto rm_fabric_grps; > + > + se_sess->sysfs_added = true; > + return 0; > + > +rm_fabric_grps: > + if (se_sess->tfo->session_attrs) > + sysfs_remove_group(&se_sess->kobj, se_sess->tfo->session_attrs); > +rm_tpt_id_grps: > + remove_transport_id_attrs(se_sess); > +del_kobj: > + kobject_del(&se_sess->kobj); > +free_acl_name: > + kfree(se_sess->acl_name); > + se_sess->acl_name = NULL; > + return ret; > +} > +EXPORT_SYMBOL(target_sysfs_add_session); > + > +void target_sysfs_remove_session(struct se_session *se_sess) > +{ > + /* discovery sessions are normally not added to sysfs */ > + if (!se_sess->sysfs_added) > + return; > + > + sysfs_remove_link(tcm_core_sessions_kobj, se_sess->kobj.name); > + if (se_sess->tfo->session_attrs) > + sysfs_remove_group(&se_sess->kobj, se_sess->tfo->session_attrs); > + remove_transport_id_attrs(se_sess); > + kobject_del(&se_sess->kobj); > +} > +EXPORT_SYMBOL(target_sysfs_remove_session); > diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c > index fdf84db..04cb042 100644 > --- a/drivers/target/target_core_transport.c > +++ b/drivers/target/target_core_transport.c > @@ -42,6 +42,7 @@ > > static struct workqueue_struct *target_completion_wq; > static struct kmem_cache *se_sess_cache; > +static DEFINE_IDA(se_sess_ida); > struct kmem_cache *se_ua_cache; > struct kmem_cache *t10_pr_reg_cache; > struct kmem_cache *t10_alua_lu_gp_cache; > @@ -251,14 +252,27 @@ struct se_session *transport_alloc_session(enum target_prot_op sup_prot_ops) > " se_sess_cache\n"); > return ERR_PTR(-ENOMEM); > } > - ret = transport_init_session(se_sess); > + > + ret = ida_simple_get(&se_sess_ida, 1, 0, GFP_KERNEL); > if (ret < 0) { > - kmem_cache_free(se_sess_cache, se_sess); > - return ERR_PTR(ret); > + pr_err("Unable to allocate session index.\n"); > + goto free_sess; > } > - se_sess->sup_prot_ops = sup_prot_ops; > + se_sess->sid = ret; > + > + ret = transport_init_session(se_sess); > + if (ret < 0) > + goto free_sid; > > + se_sess->sup_prot_ops = sup_prot_ops; > + target_sysfs_init_session(se_sess); > return se_sess; > + > +free_sid: > + ida_simple_remove(&se_sess_ida, se_sess->sid); > +free_sess: > + kmem_cache_free(se_sess_cache, se_sess); > + return ERR_PTR(ret); > } > EXPORT_SYMBOL(transport_alloc_session); > > @@ -597,12 +611,21 @@ void transport_free_session(struct se_session *se_sess) > sbitmap_queue_free(&se_sess->sess_tag_pool); > kvfree(se_sess->sess_cmd_map); > } > - target_free_transport_id(se_sess->tpt_id); > percpu_ref_exit(&se_sess->cmd_count); > - kmem_cache_free(se_sess_cache, se_sess); > + kobject_put(&se_sess->kobj); > } > EXPORT_SYMBOL(transport_free_session); > > +void __target_free_session(struct se_session *se_sess) > +{ > + kfree(se_sess->acl_name); > + target_free_transport_id(se_sess->tpt_id); > + > + ida_simple_remove(&se_sess_ida, se_sess->sid); > + > + kmem_cache_free(se_sess_cache, se_sess); > +} > + > static int target_release_res(struct se_device *dev, void *data) > { > struct se_session *sess = data; > diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h > index b7f7e02..34d89cb 100644 > --- a/include/target/target_core_base.h > +++ b/include/target/target_core_base.h > @@ -9,6 +9,7 @@ > #include <linux/semaphore.h> /* struct semaphore */ > #include <linux/completion.h> > #include <linux/kobject.h> > +#include <linux/idr.h> > > #define TARGET_CORE_VERSION "v5.0" > > @@ -626,6 +627,7 @@ struct se_session { > enum target_prot_op sup_prot_ops; > enum target_prot_type sess_prot_type; > struct se_node_acl *se_node_acl; > + char *acl_name; > struct se_portal_group *se_tpg; > void *fabric_sess_ptr; > struct percpu_ref cmd_count; > @@ -636,6 +638,10 @@ struct se_session { > wait_queue_head_t cmd_list_wq; > void *sess_cmd_map; > struct sbitmap_queue sess_tag_pool; > + struct kobject kobj; > + int sid; > + bool sysfs_added; > + const struct target_core_fabric_ops *tfo; > }; > > struct se_device; > diff --git a/include/target/target_core_fabric.h b/include/target/target_core_fabric.h > index ced377f..f876a05 100644 > --- a/include/target/target_core_fabric.h > +++ b/include/target/target_core_fabric.h > @@ -74,6 +74,10 @@ struct target_core_fabric_ops { > int (*queue_status)(struct se_cmd *); > void (*queue_tm_rsp)(struct se_cmd *); > void (*aborted_task)(struct se_cmd *); > + > + /* Optional session management and sysfs callouts */ > + const struct attribute_group *session_attrs; > + > /* > * fabric module calls for target_core_fabric_configfs.c > */ > @@ -145,7 +149,9 @@ void transport_register_session(struct se_portal_group *, > void target_put_nacl(struct se_node_acl *); > void transport_deregister_session_configfs(struct se_session *); > void transport_deregister_session(struct se_session *); > - > +void target_sysfs_remove_session(struct se_session *se_sess); > +int target_sysfs_add_session(struct se_portal_group *se_tpg, > + struct se_session *se_sess); > > void transport_init_se_cmd(struct se_cmd *, > const struct target_core_fabric_ops *, >
On 2020-05-11 11:39, Bodo Stroesser wrote: > On 05/10/20 23:57, Mike Christie wrote: >> This patch adds helpers to add/remove a dir per session. There is only 2 >> files/dirs initially. >> > > ... > >> + >> +int target_sysfs_add_session(struct se_portal_group *se_tpg, >> + struct se_session *se_sess) >> +{ >> + int ret; >> + >> + /* >> + * Copy ACL name so we don't have to worry about mixing configfs >> + * and sysfs refcounts. >> + */ >> + if (!se_sess->se_node_acl->dynamic_node_acl) { >> + se_sess->acl_name = kstrdup(se_sess->se_node_acl->initiatorname, >> + GFP_KERNEL); >> + if (!se_sess->acl_name) >> + return -ENOMEM; >> + } >> + >> + ret = kobject_add(&se_sess->kobj, se_tpg->sessions_kobj, "%s-%d", >> + se_sess->tpt_id->name, se_sess->sid); >> + if (ret) { >> + pr_err("Could not add session%d to sysfs. Error %d.\n", >> + se_sess->sid, ret); >> + goto free_acl_name; >> + } >> + >> + ret = add_transport_id_attrs(se_sess); >> + if (ret) >> + goto del_kobj; >> + >> + if (se_sess->tfo->session_attrs) { >> + ret = sysfs_create_group(&se_sess->kobj, >> + se_sess->tfo->session_attrs); >> + if (ret) >> + goto rm_tpt_id_grps; >> + } >> + >> + ret = sysfs_create_link(tcm_core_sessions_kobj, &se_sess->kobj, >> + se_sess->kobj.name); > > I would prefer to have links named "session-%d" or "%d" only, of course > with se_sess->sid as the value for '%d'. Isn't se_sess->sid a property that is filled in by the iSCSI target driver only? Is se_sess->sid zero for all other target drivers than the iSCSI target driver? > If userspace knows the session-id only, such names make it easier to > find the corresponding link. Personally I prefer the %s-%d naming scheme. I think that naming scheme has the following advantages: 1. No need to run cat ... to retrieve the initiator name. 2. It becomes possible to derive from the 'ls' output which initiators created multiple sessions. 3. All sessions created by the same initiator appear consecutively. Thanks, Bart.
On 5/11/20 2:21 PM, Bart Van Assche wrote: > On 2020-05-11 11:39, Bodo Stroesser wrote: >> On 05/10/20 23:57, Mike Christie wrote: >>> This patch adds helpers to add/remove a dir per session. There is only 2 >>> files/dirs initially. >>> >> >> ... >> >>> + >>> +int target_sysfs_add_session(struct se_portal_group *se_tpg, >>> + struct se_session *se_sess) >>> +{ >>> + int ret; >>> + >>> + /* >>> + * Copy ACL name so we don't have to worry about mixing configfs >>> + * and sysfs refcounts. >>> + */ >>> + if (!se_sess->se_node_acl->dynamic_node_acl) { >>> + se_sess->acl_name = kstrdup(se_sess->se_node_acl->initiatorname, >>> + GFP_KERNEL); >>> + if (!se_sess->acl_name) >>> + return -ENOMEM; >>> + } >>> + >>> + ret = kobject_add(&se_sess->kobj, se_tpg->sessions_kobj, "%s-%d", >>> + se_sess->tpt_id->name, se_sess->sid); >>> + if (ret) { >>> + pr_err("Could not add session%d to sysfs. Error %d.\n", >>> + se_sess->sid, ret); >>> + goto free_acl_name; >>> + } >>> + >>> + ret = add_transport_id_attrs(se_sess); >>> + if (ret) >>> + goto del_kobj; >>> + >>> + if (se_sess->tfo->session_attrs) { >>> + ret = sysfs_create_group(&se_sess->kobj, >>> + se_sess->tfo->session_attrs); >>> + if (ret) >>> + goto rm_tpt_id_grps; >>> + } >>> + >>> + ret = sysfs_create_link(tcm_core_sessions_kobj, &se_sess->kobj, >>> + se_sess->kobj.name); >> >> I would prefer to have links named "session-%d" or "%d" only, of course >> with se_sess->sid as the value for '%d'. Yeah for the part of your comment that got chopped I can see your point. For the dynamic acl case (userspace did not create an ACL so the kernel made a tmp one), then doing session-$id will be easier for userspace to lookup a specific session since it does not know the initiator name and only knows the session id. > > Isn't se_sess->sid a property that is filled in by the iSCSI target > driver only? Is se_sess->sid zero for all other target drivers than the > iSCSI target driver? No, in this patch in transport_alloc_session() I added a common sid allocator so all sessions have a unique id across all targets. > >> If userspace knows the session-id only, such names make it easier to >> find the corresponding link. > > Personally I prefer the %s-%d naming scheme. I think that naming scheme > has the following advantages: > 1. No need to run cat ... to retrieve the initiator name. > 2. It becomes possible to derive from the 'ls' output which initiators > created multiple sessions. > 3. All sessions created by the same initiator appear consecutively. > Ccing Hannes, because he was also saying that we should use generic names like target-%X, session-$d, etc. If we change all the code to use generic names for the target/fabric/tpgt/session, then examples like #2 or similar ones like using tree to see the topology from a SCSI'ish view would not work. In the end, we have this issue with SCSI on the initiator side, and it's a pain, but not a show stopper.
On 05/11/20 22:16, Mike Christie wrote: > On 5/11/20 2:21 PM, Bart Van Assche wrote: >> On 2020-05-11 11:39, Bodo Stroesser wrote: >>> On 05/10/20 23:57, Mike Christie wrote: >>>> This patch adds helpers to add/remove a dir per session. There is only 2 >>>> files/dirs initially. >>>> >>> >>> ... >>> >>>> + >>>> +int target_sysfs_add_session(struct se_portal_group *se_tpg, >>>> + struct se_session *se_sess) >>>> +{ >>>> + int ret; >>>> + >>>> + /* >>>> + * Copy ACL name so we don't have to worry about mixing configfs >>>> + * and sysfs refcounts. >>>> + */ >>>> + if (!se_sess->se_node_acl->dynamic_node_acl) { >>>> + se_sess->acl_name = kstrdup(se_sess->se_node_acl->initiatorname, >>>> + GFP_KERNEL); >>>> + if (!se_sess->acl_name) >>>> + return -ENOMEM; >>>> + } >>>> + >>>> + ret = kobject_add(&se_sess->kobj, se_tpg->sessions_kobj, "%s-%d", >>>> + se_sess->tpt_id->name, se_sess->sid); >>>> + if (ret) { >>>> + pr_err("Could not add session%d to sysfs. Error %d.\n", >>>> + se_sess->sid, ret); >>>> + goto free_acl_name; >>>> + } >>>> + >>>> + ret = add_transport_id_attrs(se_sess); >>>> + if (ret) >>>> + goto del_kobj; >>>> + >>>> + if (se_sess->tfo->session_attrs) { >>>> + ret = sysfs_create_group(&se_sess->kobj, >>>> + se_sess->tfo->session_attrs); >>>> + if (ret) >>>> + goto rm_tpt_id_grps; >>>> + } >>>> + >>>> + ret = sysfs_create_link(tcm_core_sessions_kobj, &se_sess->kobj, >>>> + se_sess->kobj.name); >>> >>> I would prefer to have links named "session-%d" or "%d" only, of course >>> with se_sess->sid as the value for '%d'. > > Yeah for the part of your comment that got chopped I can see your point. > For the dynamic acl case (userspace did not create an ACL so the kernel > made a tmp one), then doing session-$id will be easier for userspace to > lookup a specific session since it does not know the initiator name and > only knows the session id. Yes, I meant, that "session-%d" or even "%d" only would be fine for the links in scsi_target/sessions. When looking for a session if session-id is known only, then this is easy to use. Regarding the session folders in the tpgt_X folder, I think the "%s-%d" format with acl or initiator name followed by the session-id would be fine for both cases, with acl and with dynamic acl. Again the above links can be used for dynamic acl lookup. > >> >> Isn't se_sess->sid a property that is filled in by the iSCSI target >> driver only? Is se_sess->sid zero for all other target drivers than the >> iSCSI target driver? > > No, in this patch in transport_alloc_session() I added a common sid > allocator so all sessions have a unique id across all targets. > >> >>> If userspace knows the session-id only, such names make it easier to >>> find the corresponding link. >> >> Personally I prefer the %s-%d naming scheme. I think that naming scheme >> has the following advantages: >> 1. No need to run cat ... to retrieve the initiator name. >> 2. It becomes possible to derive from the 'ls' output which initiators >> created multiple sessions. >> 3. All sessions created by the same initiator appear consecutively. >> > > Ccing Hannes, because he was also saying that we should use generic > names like target-%X, session-$d, etc. If we change all the code to use > generic names for the target/fabric/tpgt/session, then examples like #2 > or similar ones like using tree to see the topology from a SCSI'ish view > would not work. > > In the end, we have this issue with SCSI on the initiator side, and it's > a pain, but not a show stopper. >
On 5/12/20 6:19 AM, Bodo Stroesser wrote: > On 05/11/20 22:16, Mike Christie wrote: >> On 5/11/20 2:21 PM, Bart Van Assche wrote: >>> On 2020-05-11 11:39, Bodo Stroesser wrote: >>>> On 05/10/20 23:57, Mike Christie wrote: >>>>> This patch adds helpers to add/remove a dir per session. There is >>>>> only 2 >>>>> files/dirs initially. >>>>> >>>> >>>> ... >>>> >>>>> + >>>>> +int target_sysfs_add_session(struct se_portal_group *se_tpg, >>>>> + struct se_session *se_sess) >>>>> +{ >>>>> + int ret; >>>>> + >>>>> + /* >>>>> + * Copy ACL name so we don't have to worry about mixing configfs >>>>> + * and sysfs refcounts. >>>>> + */ >>>>> + if (!se_sess->se_node_acl->dynamic_node_acl) { >>>>> + se_sess->acl_name = >>>>> kstrdup(se_sess->se_node_acl->initiatorname, >>>>> + GFP_KERNEL); >>>>> + if (!se_sess->acl_name) >>>>> + return -ENOMEM; >>>>> + } >>>>> + >>>>> + ret = kobject_add(&se_sess->kobj, se_tpg->sessions_kobj, "%s-%d", >>>>> + se_sess->tpt_id->name, se_sess->sid); >>>>> + if (ret) { >>>>> + pr_err("Could not add session%d to sysfs. Error %d.\n", >>>>> + se_sess->sid, ret); >>>>> + goto free_acl_name; >>>>> + } >>>>> + >>>>> + ret = add_transport_id_attrs(se_sess); >>>>> + if (ret) >>>>> + goto del_kobj; >>>>> + >>>>> + if (se_sess->tfo->session_attrs) { >>>>> + ret = sysfs_create_group(&se_sess->kobj, >>>>> + se_sess->tfo->session_attrs); >>>>> + if (ret) >>>>> + goto rm_tpt_id_grps; >>>>> + } >>>>> + >>>>> + ret = sysfs_create_link(tcm_core_sessions_kobj, &se_sess->kobj, >>>>> + se_sess->kobj.name); >>>> >>>> I would prefer to have links named "session-%d" or "%d" only, of course >>>> with se_sess->sid as the value for '%d'. >> >> Yeah for the part of your comment that got chopped I can see your point. >> For the dynamic acl case (userspace did not create an ACL so the kernel >> made a tmp one), then doing session-$id will be easier for userspace to >> lookup a specific session since it does not know the initiator name and >> only knows the session id. > > Yes, I meant, that "session-%d" or even "%d" only would be fine for the > links in scsi_target/sessions. When looking for a session if session-id > is known only, then this is easy to use. > > Regarding the session folders in the tpgt_X folder, I think the "%s-%d" > format with acl or initiator name followed by the session-id would be > fine for both cases, with acl and with dynamic acl. Again the above > links can be used for dynamic acl lookup. > I don't think that's possible. To handle Greg's comment we will use device structs instead of kobjects directly. It's going to end up looking like drivers/scsi_transport_iscsi.c where that initiator side session has a device struct in it. You have a scsi_target_session class and device structs show up in /sys/class/scsi_target_session. In this case, you do not have control over the symlink name from /sys/class/scsi_target_session to /sys/devices/. The dir name and symlink name are going to be the device structs name.
diff --git a/Documentation/ABI/testing/sysfs-scsi-target b/Documentation/ABI/testing/sysfs-scsi-target new file mode 100644 index 0000000..0408798 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-scsi-target @@ -0,0 +1,46 @@ +What: /sys/scsi_target/<fabric>/<target>/<tpgt_N>/sessions/<initiator-X> +Date: May 9, 2020 +KernelVersion: 5.8 +Contact: linux-scsi@vger.kernel.org +Description: The sessions dir contains a dir for each I_T Nexus. The name of + the dir is initiator port name followed by an integer that is + unique across all fabrics. The dir contains files that export + info like the ACL being used, SCSI port values, and fabric and + transport specific values. + +What: /sys/scsi_target/<fabric>/.../sessions/<initiator-X>/acl +Date: May 9, 2020 +KernelVersion: 5.8 +Contact: linux-scsi@vger.kernel.org +Description: Returns the name of the ACL that was used to validate login or + an empty string if no user created ACL was used. + +What: /sys/scsi_target/<fabric>/.../sessions/<initiator-X/transport_id +Date: May 9, 2020 +KernelVersion: 5.8 +Contact: linux-scsi@vger.kernel.org +Description: The transport_id contains the SCSI TransportID values for the + initiator port as defined in SPC4r37. + +What: /sys/scsi_target/<fabric>/.../sessions/<initiator-X/transport_id/proto +Date: May 9, 2020 +KernelVersion: 5.8 +Contact: linux-scsi@vger.kernel.org +Description: Returns the SCSI protocol identifier in hex defined in SPC4r37. + +What: /sys/scsi_target/<fabric>/.../sessions/<initiator-X/transport_id/name +Date: May 9, 2020 +KernelVersion: 5.8 +Contact: linux-scsi@vger.kernel.org +Description: Returns the port name/address/id in the protocol specific + TransportID format defined in SPC4r37's. + +What: /sys/scsi_target/<fabric>/.../sessions/<initiator-X/transport_id/session_id +Date: May 9, 2020 +KernelVersion: 5.8 +Contact: linux-scsi@vger.kernel.org +Description: If is proto=0x5 (iSCSI) and TPID FORMAT=1 this file will exist + and will return the iSCSI Initiator Session ID in ASCII + characters that are the hexadecimal digits converted from the + binary iSCSI initiator session identifier value. If iSCSI and + format=1 is not used by this session this file will not exist. diff --git a/drivers/target/Makefile b/drivers/target/Makefile index 4563474..4a7246e 100644 --- a/drivers/target/Makefile +++ b/drivers/target/Makefile @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 target_core_mod-y := target_core_configfs.o \ + target_core_sysfs.o \ target_core_device.o \ target_core_fabric_configfs.o \ target_core_fabric_lib.o \ diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c index 3eb2566..7a9f607 100644 --- a/drivers/target/target_core_configfs.c +++ b/drivers/target/target_core_configfs.c @@ -64,7 +64,7 @@ } static struct kobject *tcm_core_kobj; -static struct kobject *tcm_core_sessions_kobj; +struct kobject *tcm_core_sessions_kobj; extern struct t10_alua_lu_gp *default_lu_gp; diff --git a/drivers/target/target_core_internal.h b/drivers/target/target_core_internal.h index 16ae020..5bf216f 100644 --- a/drivers/target/target_core_internal.h +++ b/drivers/target/target_core_internal.h @@ -91,6 +91,7 @@ int target_for_each_device(int (*fn)(struct se_device *dev, void *data), void *data); /* target_core_configfs.c */ +extern struct kobject *tcm_core_sessions_kobj; extern struct configfs_item_operations target_core_dev_item_ops; void target_setup_backend_cits(struct target_backend *); @@ -106,6 +107,9 @@ int target_get_pr_transport_id(struct se_node_acl *nacl, const char *target_parse_pr_out_transport_id(struct se_portal_group *tpg, char *buf, u32 *out_tid_len, char **port_nexus_ptr); +/* target_core_sysfs.c */ +void target_sysfs_init_session(struct se_session *sess); + /* target_core_hba.c */ struct se_hba *core_alloc_hba(const char *, u32, u32); int core_delete_hba(struct se_hba *); @@ -153,6 +157,7 @@ void transport_dump_dev_info(struct se_device *, struct se_lun *, bool target_check_wce(struct se_device *dev); bool target_check_fua(struct se_device *dev); void __target_execute_cmd(struct se_cmd *, bool); +void __target_free_session(struct se_session *); /* target_core_stat.c */ void target_stat_setup_dev_default_groups(struct se_device *); diff --git a/drivers/target/target_core_sysfs.c b/drivers/target/target_core_sysfs.c new file mode 100644 index 0000000..f8353a9 --- /dev/null +++ b/drivers/target/target_core_sysfs.c @@ -0,0 +1,233 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/kobject.h> +#include <linux/idr.h> + +#include <scsi/scsi_proto.h> + +#include <target/target_core_base.h> +#include <target/target_core_fabric.h> +#include "target_core_internal.h" + +static void target_sysfs_session_release(struct kobject *kobj) +{ + struct se_session *se_sess = container_of(kobj, struct se_session, kobj); + + __target_free_session(se_sess); +} + +struct session_attr { + struct attribute attr; + ssize_t (*show)(struct se_session *, char *); + ssize_t (*store)(struct se_session *, const char *, size_t); +}; + +#define to_session(atr) container_of((atr), struct session_attr, attr) + +static ssize_t session_acl_show(struct se_session *se_sess, char *page) +{ + return snprintf(page, PAGE_SIZE, "%s", se_sess->acl_name ? + se_sess->acl_name : ""); +} + +static struct session_attr session_acl_attr = { + .attr = { .name = "acl", .mode = S_IRUGO }, + .show = session_acl_show, +}; + +/* Default attrs common to all fabric modules */ +static struct attribute *session_attrs[] = { + &session_acl_attr.attr, + NULL +}; + +static const struct attribute_group session_group = { + .attrs = session_attrs, +}; + +/* transportID attrs */ +#define tpt_id_attr_show(name, fmt_str) \ +static ssize_t show_##name(struct se_session *se_sess, char *page) \ +{ \ + return snprintf(page, PAGE_SIZE, fmt_str, se_sess->tpt_id->name); \ +} + +#define tpt_id_attr(name, fmt_str) \ + tpt_id_attr_show(name, fmt_str) \ +static struct session_attr tpt_id_##name##_attr = \ + __ATTR(name, S_IRUGO, show_##name, NULL) + +tpt_id_attr(proto, "0x%x"); +tpt_id_attr(name, "%s"); + +static ssize_t session_id_show(struct se_session *se_sess, char *page) +{ + if (!se_sess->tpt_id->session_id) + return 0; + + return snprintf(page, PAGE_SIZE, "0x%s", se_sess->tpt_id->session_id); +} + +static struct session_attr tpt_id_session_id_attr = { + .attr = { .name = "session_id", .mode = S_IRUGO }, + .show = session_id_show, +}; + +/* + * The drivers that emulate iSCSI like loop/vhost/xen do not support format=1, + * so we only separate based on format and not also proto. + */ +static struct attribute *tpt_id_fmt0_attrs[] = { + &tpt_id_proto_attr.attr, + &tpt_id_name_attr.attr, + NULL +}; + +static const struct attribute_group tpt_id_fmt0_group = { + .name = "transport_id", + .attrs = tpt_id_fmt0_attrs, +}; + +static struct attribute *tpt_id_fmt1_attrs[] = { + &tpt_id_proto_attr.attr, + &tpt_id_name_attr.attr, + &tpt_id_session_id_attr.attr, + NULL +}; + +static const struct attribute_group tpt_id_fmt1_group = { + .name = "transport_id", + .attrs = tpt_id_fmt1_attrs, +}; + +static ssize_t +session_attr_store(struct kobject *kobj, struct attribute *attr, + const char *page, size_t length) +{ + struct se_session *se_sess = container_of(kobj, struct se_session, kobj); + struct session_attr *sess_attr = to_session(attr); + + if (!sess_attr->store) + return -ENOSYS; + + return sess_attr->store(se_sess, page, length); +} + +static ssize_t +session_attr_show(struct kobject *kobj, struct attribute *attr, char *page) +{ + struct se_session *se_sess = container_of(kobj, struct se_session, kobj); + struct session_attr *sess_attr = to_session(attr); + + if (!sess_attr->show) + return -ENOSYS; + + return sess_attr->show(se_sess, page); +} + +static const struct sysfs_ops session_sysfs_ops = { + .show = session_attr_show, + .store = session_attr_store, +}; + +static const struct attribute_group *def_session_groups[] = { + &session_group, + NULL +}; + +static struct kobj_type session_ktype = { + .sysfs_ops = &session_sysfs_ops, + .release = target_sysfs_session_release, + .default_groups = def_session_groups, +}; + +void target_sysfs_init_session(struct se_session *se_sess) +{ + kobject_init(&se_sess->kobj, &session_ktype); +} + +static int add_transport_id_attrs(struct se_session *se_sess) +{ + if (se_sess->tpt_id->session_id) + return sysfs_create_group(&se_sess->kobj, &tpt_id_fmt1_group); + else + return sysfs_create_group(&se_sess->kobj, &tpt_id_fmt0_group); +} + +static void remove_transport_id_attrs(struct se_session *se_sess) +{ + if (se_sess->tpt_id->session_id) + sysfs_remove_group(&se_sess->kobj, &tpt_id_fmt1_group); + else + sysfs_remove_group(&se_sess->kobj, &tpt_id_fmt0_group); +} + +int target_sysfs_add_session(struct se_portal_group *se_tpg, + struct se_session *se_sess) +{ + int ret; + + /* + * Copy ACL name so we don't have to worry about mixing configfs + * and sysfs refcounts. + */ + if (!se_sess->se_node_acl->dynamic_node_acl) { + se_sess->acl_name = kstrdup(se_sess->se_node_acl->initiatorname, + GFP_KERNEL); + if (!se_sess->acl_name) + return -ENOMEM; + } + + ret = kobject_add(&se_sess->kobj, se_tpg->sessions_kobj, "%s-%d", + se_sess->tpt_id->name, se_sess->sid); + if (ret) { + pr_err("Could not add session%d to sysfs. Error %d.\n", + se_sess->sid, ret); + goto free_acl_name; + } + + ret = add_transport_id_attrs(se_sess); + if (ret) + goto del_kobj; + + if (se_sess->tfo->session_attrs) { + ret = sysfs_create_group(&se_sess->kobj, + se_sess->tfo->session_attrs); + if (ret) + goto rm_tpt_id_grps; + } + + ret = sysfs_create_link(tcm_core_sessions_kobj, &se_sess->kobj, + se_sess->kobj.name); + if (ret) + goto rm_fabric_grps; + + se_sess->sysfs_added = true; + return 0; + +rm_fabric_grps: + if (se_sess->tfo->session_attrs) + sysfs_remove_group(&se_sess->kobj, se_sess->tfo->session_attrs); +rm_tpt_id_grps: + remove_transport_id_attrs(se_sess); +del_kobj: + kobject_del(&se_sess->kobj); +free_acl_name: + kfree(se_sess->acl_name); + se_sess->acl_name = NULL; + return ret; +} +EXPORT_SYMBOL(target_sysfs_add_session); + +void target_sysfs_remove_session(struct se_session *se_sess) +{ + /* discovery sessions are normally not added to sysfs */ + if (!se_sess->sysfs_added) + return; + + sysfs_remove_link(tcm_core_sessions_kobj, se_sess->kobj.name); + if (se_sess->tfo->session_attrs) + sysfs_remove_group(&se_sess->kobj, se_sess->tfo->session_attrs); + remove_transport_id_attrs(se_sess); + kobject_del(&se_sess->kobj); +} +EXPORT_SYMBOL(target_sysfs_remove_session); diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index fdf84db..04cb042 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -42,6 +42,7 @@ static struct workqueue_struct *target_completion_wq; static struct kmem_cache *se_sess_cache; +static DEFINE_IDA(se_sess_ida); struct kmem_cache *se_ua_cache; struct kmem_cache *t10_pr_reg_cache; struct kmem_cache *t10_alua_lu_gp_cache; @@ -251,14 +252,27 @@ struct se_session *transport_alloc_session(enum target_prot_op sup_prot_ops) " se_sess_cache\n"); return ERR_PTR(-ENOMEM); } - ret = transport_init_session(se_sess); + + ret = ida_simple_get(&se_sess_ida, 1, 0, GFP_KERNEL); if (ret < 0) { - kmem_cache_free(se_sess_cache, se_sess); - return ERR_PTR(ret); + pr_err("Unable to allocate session index.\n"); + goto free_sess; } - se_sess->sup_prot_ops = sup_prot_ops; + se_sess->sid = ret; + + ret = transport_init_session(se_sess); + if (ret < 0) + goto free_sid; + se_sess->sup_prot_ops = sup_prot_ops; + target_sysfs_init_session(se_sess); return se_sess; + +free_sid: + ida_simple_remove(&se_sess_ida, se_sess->sid); +free_sess: + kmem_cache_free(se_sess_cache, se_sess); + return ERR_PTR(ret); } EXPORT_SYMBOL(transport_alloc_session); @@ -597,12 +611,21 @@ void transport_free_session(struct se_session *se_sess) sbitmap_queue_free(&se_sess->sess_tag_pool); kvfree(se_sess->sess_cmd_map); } - target_free_transport_id(se_sess->tpt_id); percpu_ref_exit(&se_sess->cmd_count); - kmem_cache_free(se_sess_cache, se_sess); + kobject_put(&se_sess->kobj); } EXPORT_SYMBOL(transport_free_session); +void __target_free_session(struct se_session *se_sess) +{ + kfree(se_sess->acl_name); + target_free_transport_id(se_sess->tpt_id); + + ida_simple_remove(&se_sess_ida, se_sess->sid); + + kmem_cache_free(se_sess_cache, se_sess); +} + static int target_release_res(struct se_device *dev, void *data) { struct se_session *sess = data; diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h index b7f7e02..34d89cb 100644 --- a/include/target/target_core_base.h +++ b/include/target/target_core_base.h @@ -9,6 +9,7 @@ #include <linux/semaphore.h> /* struct semaphore */ #include <linux/completion.h> #include <linux/kobject.h> +#include <linux/idr.h> #define TARGET_CORE_VERSION "v5.0" @@ -626,6 +627,7 @@ struct se_session { enum target_prot_op sup_prot_ops; enum target_prot_type sess_prot_type; struct se_node_acl *se_node_acl; + char *acl_name; struct se_portal_group *se_tpg; void *fabric_sess_ptr; struct percpu_ref cmd_count; @@ -636,6 +638,10 @@ struct se_session { wait_queue_head_t cmd_list_wq; void *sess_cmd_map; struct sbitmap_queue sess_tag_pool; + struct kobject kobj; + int sid; + bool sysfs_added; + const struct target_core_fabric_ops *tfo; }; struct se_device; diff --git a/include/target/target_core_fabric.h b/include/target/target_core_fabric.h index ced377f..f876a05 100644 --- a/include/target/target_core_fabric.h +++ b/include/target/target_core_fabric.h @@ -74,6 +74,10 @@ struct target_core_fabric_ops { int (*queue_status)(struct se_cmd *); void (*queue_tm_rsp)(struct se_cmd *); void (*aborted_task)(struct se_cmd *); + + /* Optional session management and sysfs callouts */ + const struct attribute_group *session_attrs; + /* * fabric module calls for target_core_fabric_configfs.c */ @@ -145,7 +149,9 @@ void transport_register_session(struct se_portal_group *, void target_put_nacl(struct se_node_acl *); void transport_deregister_session_configfs(struct se_session *); void transport_deregister_session(struct se_session *); - +void target_sysfs_remove_session(struct se_session *se_sess); +int target_sysfs_add_session(struct se_portal_group *se_tpg, + struct se_session *se_sess); void transport_init_se_cmd(struct se_cmd *, const struct target_core_fabric_ops *,
This patch adds helpers to add/remove a dir per session. There is only 2 files/dirs initially. acl - name of acl session is accessed through. transport_id - Contains fabric module specific transportID values. See sysfs-scsi-target below for more info on each file/dir. scsi_target/ |-- iscsi | `-- iqn.1999-09.com.tcmu:minna | `-- tpgt_1 | `-- sessions | `-- iqn.2005-03.com.ceph:ini1-1 | |-- acl | `-- transport_id | |-- name | |-- proto | `-- session_id Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Mike Christie <mchristi@redhat.com> --- V4: - add Documentation/ABI - use initaitor port prefix instead of generic "session" V3: - add session symlink - use simple ida. V2: - Fix extra newline - Copy data that's exported to sysfs so we do not have to worry about configfs and sysfs refcounts. - adds back the global sid allocator instead of the per tpg one because in the future we will want to tag target_core_user commands with the session id. This will be needed when tcmu devices are mapped to multiple fabric modules or tpgs and they userspace needs to track the different session to command mappings for commands like PRs. Documentation/ABI/testing/sysfs-scsi-target | 46 ++++++ drivers/target/Makefile | 1 + drivers/target/target_core_configfs.c | 2 +- drivers/target/target_core_internal.h | 5 + drivers/target/target_core_sysfs.c | 233 ++++++++++++++++++++++++++++ drivers/target/target_core_transport.c | 35 ++++- include/target/target_core_base.h | 6 + include/target/target_core_fabric.h | 8 +- 8 files changed, 328 insertions(+), 8 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-scsi-target create mode 100644 drivers/target/target_core_sysfs.c