From: James Smart Date: Thu, 24 May 2007 23:04:44 +0000 (-0400) Subject: [SCSI] fc_transport: fix sysfs deadlock on vport delete X-Git-Tag: v2.6.23-rc1~1053^2~143 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9ef3e4a4527e1f65b8776287c6d4fd1fca5ba98f;p=linux-2.6 [SCSI] fc_transport: fix sysfs deadlock on vport delete When the vport attribute "delete" is used to delete the vport, sysfs deadlocks waiting for the write to complete, which is waiting for the sysfs teardown to complete. Moved this effort to a work_q element. Took the opportunity to make some other cosmetic changes: - removed tabs in Doc file - replaced with expanded spaces - minor copyright text and author text updates - removed a bunch of trailing whitespace Signed-off-by: James Smart Signed-off-by: James Bottomley --- diff --git a/Documentation/scsi/scsi_fc_transport.txt b/Documentation/scsi/scsi_fc_transport.txt index ab057afc75..d403e46d84 100644 --- a/Documentation/scsi/scsi_fc_transport.txt +++ b/Documentation/scsi/scsi_fc_transport.txt @@ -119,67 +119,67 @@ Vport Attributes: The new fc_vport class object has the following attributes - node_name: Read_Only + node_name: Read_Only The WWNN of the vport - port_name: Read_Only + port_name: Read_Only The WWPN of the vport - roles: Read_Only + roles: Read_Only Indicates the FC4 roles enabled on the vport. - symbolic_name: Read_Write + symbolic_name: Read_Write A string, appended to the driver's symbolic port name string, which is registered with the switch to identify the vport. For example, a hypervisor could set this string to "Xen Domain 2 VM 5 Vport 2", and this set of identifiers can be seen on switch management screens to identify the port. - vport_delete: Write_Only + vport_delete: Write_Only When written with a "1", will tear down the vport. - vport_disable: Write_Only + vport_disable: Write_Only When written with a "1", will transition the vport to a disabled. state. The vport will still be instantiated with the Linux kernel, but it will not be active on the FC link. When written with a "0", will enable the vport. - vport_last_state: Read_Only + vport_last_state: Read_Only Indicates the previous state of the vport. See the section below on "Vport States". - vport_state: Read_Only + vport_state: Read_Only Indicates the state of the vport. See the section below on "Vport States". - vport_type: Read_Only + vport_type: Read_Only Reflects the FC mechanism used to create the virtual port. Only NPIV is supported currently. For the fc_host class object, the following attributes are added for vports: - max_npiv_vports: Read_Only + max_npiv_vports: Read_Only Indicates the maximum number of NPIV-based vports that the driver/adapter can support on the fc_host. - npiv_vports_inuse: Read_Only + npiv_vports_inuse: Read_Only Indicates how many NPIV-based vports have been instantiated on the fc_host. - vport_create: Write_Only + vport_create: Write_Only A "simple" create interface to instantiate a vport on an fc_host. A ":" string is written to the attribute. The transport then instantiates the vport object and calls the LLDD to create the vport with the role of FCP_Initiator. Each WWN is specified as 16 hex characters and may *not* contain any prefixes (e.g. 0x, x, etc). - vport_delete: Write_Only + vport_delete: Write_Only A "simple" delete interface to teardown a vport. A ":" - string is written to the attribute. The transport will locate the - vport on the fc_host with the same WWNs and tear it down. Each WWN - is specified as 16 hex characters and may *not* contain any prefixes - (e.g. 0x, x, etc). + string is written to the attribute. The transport will locate the + vport on the fc_host with the same WWNs and tear it down. Each WWN + is specified as 16 hex characters and may *not* contain any prefixes + (e.g. 0x, x, etc). Vport States: @@ -198,23 +198,23 @@ Vport States: Once a vport has been instantiated with the kernel/LLDD, a vport state can be reported via the sysfs attribute. The following states exist: - FC_VPORT_UNKNOWN - Unknown + FC_VPORT_UNKNOWN - Unknown An temporary state, typically set only while the vport is being instantiated with the kernel and LLDD. - FC_VPORT_ACTIVE - Active + FC_VPORT_ACTIVE - Active The vport has been successfully been created on the FC link. It is fully functional. - FC_VPORT_DISABLED - Disabled + FC_VPORT_DISABLED - Disabled The vport instantiated, but "disabled". The vport is not instantiated on the FC link. This is equivalent to a physical port with the link "down". - FC_VPORT_LINKDOWN - Linkdown + FC_VPORT_LINKDOWN - Linkdown The vport is not operational as the physical link is not operational. - FC_VPORT_INITIALIZING - Initializing + FC_VPORT_INITIALIZING - Initializing The vport is in the process of instantiating on the FC link. The LLDD will set this state just prior to starting the ELS traffic to create the vport. This state will persist until the vport is @@ -222,65 +222,65 @@ Vport States: (state is one of the values below). As this state is transitory, it will not be preserved in the "vport_last_state". - FC_VPORT_NO_FABRIC_SUPP - No Fabric Support + FC_VPORT_NO_FABRIC_SUPP - No Fabric Support The vport is not operational. One of the following conditions were encountered: - The FC topology is not Point-to-Point - The FC port is not connected to an F_Port - The F_Port has indicated that NPIV is not supported. - FC_VPORT_NO_FABRIC_RSCS - No Fabric Resources + FC_VPORT_NO_FABRIC_RSCS - No Fabric Resources The vport is not operational. The Fabric failed FDISC with a status indicating that it does not have sufficient resources to complete the operation. - FC_VPORT_FABRIC_LOGOUT - Fabric Logout + FC_VPORT_FABRIC_LOGOUT - Fabric Logout The vport is not operational. The Fabric has LOGO'd the N_Port_ID associated with the vport. - FC_VPORT_FABRIC_REJ_WWN - Fabric Rejected WWN + FC_VPORT_FABRIC_REJ_WWN - Fabric Rejected WWN The vport is not operational. The Fabric failed FDISC with a status indicating that the WWN's are not valid. - FC_VPORT_FAILED - VPort Failed + FC_VPORT_FAILED - VPort Failed The vport is not operational. This is a catchall for all other error conditions. The following state table indicates the different state transitions: - State Event New State + State Event New State -------------------------------------------------------------------- - n/a Initialization Unknown - Unknown: Link Down Linkdown - Link Up & Loop No Fabric Support - Link Up & no Fabric No Fabric Support - Link Up & FLOGI response No Fabric Support - indicates no NPIV support - Link Up & FDISC being sent Initializing - Disable request Disable - Linkdown: Link Up Unknown - Initializing: FDISC ACC Active - FDISC LS_RJT w/ no resources No Fabric Resources - FDISC LS_RJT w/ invalid Fabric Rejected WWN - pname or invalid nport_id - FDISC LS_RJT failed for Vport Failed - other reasons - Link Down Linkdown - Disable request Disable - Disable: Enable request Unknown - Active: LOGO received from fabric Fabric Logout - Link Down Linkdown - Disable request Disable - Fabric Logout: Link still up Unknown + n/a Initialization Unknown + Unknown: Link Down Linkdown + Link Up & Loop No Fabric Support + Link Up & no Fabric No Fabric Support + Link Up & FLOGI response No Fabric Support + indicates no NPIV support + Link Up & FDISC being sent Initializing + Disable request Disable + Linkdown: Link Up Unknown + Initializing: FDISC ACC Active + FDISC LS_RJT w/ no resources No Fabric Resources + FDISC LS_RJT w/ invalid Fabric Rejected WWN + pname or invalid nport_id + FDISC LS_RJT failed for Vport Failed + other reasons + Link Down Linkdown + Disable request Disable + Disable: Enable request Unknown + Active: LOGO received from fabric Fabric Logout + Link Down Linkdown + Disable request Disable + Fabric Logout: Link still up Unknown The following 4 error states all have the same transitions: No Fabric Support: No Fabric Resources: Fabric Rejected WWN: Vport Failed: - Disable request Disable - Link goes down Linkdown + Disable request Disable + Link goes down Linkdown Transport <-> LLDD Interfaces : @@ -303,9 +303,9 @@ Vport Creation: int vport_create(struct fc_vport *vport, bool disable) where: - vport: Is the newly allocated vport object - disable: If "true", the vport is to be created in a disabled stated. - If "false", the vport is to be enabled upon creation. + vport: Is the newly allocated vport object + disable: If "true", the vport is to be created in a disabled stated. + If "false", the vport is to be enabled upon creation. When a request is made to create a new vport (via sgio/netlink, or the vport_create fc_host attribute), the transport will validate that the LLDD @@ -342,7 +342,7 @@ Vport Creation: - Validate Infrastructure: - If the driver or adapter cannot support another vport, whether due to improper firmware, (a lie about) max_npiv, or a lack of - some other resource - return VPCERR_UNSUPPORTED. + some other resource - return VPCERR_UNSUPPORTED. - If the driver validates the WWN's against those already active on the adapter and detects an overlap - return VPCERR_BAD_WWN. - If the driver detects the topology is loop, non-fabric, or the @@ -351,9 +351,9 @@ Vport Creation: of memory conditions, return the respective negative Exxx error code. - If the role is FCP Initiator, the LLDD is to : - Call scsi_host_alloc() to allocate a scsi_host for the vport. - - Call scsi_add_host(new_shost, &vport->dev) to start the scsi_host - and bind it as a child of the vport device. - - Initializes the fc_host attribute values. + - Call scsi_add_host(new_shost, &vport->dev) to start the scsi_host + and bind it as a child of the vport device. + - Initializes the fc_host attribute values. - Kick of further vport state transitions based on the disable flag and link state - and return success (zero). @@ -376,9 +376,9 @@ Vport Disable/Enable: int vport_disable(struct fc_vport *vport, bool disable) where: - vport: Is vport to to be enabled or disabled - disable: If "true", the vport is to be disabled. - If "false", the vport is to be enabled. + vport: Is vport to to be enabled or disabled + disable: If "true", the vport is to be disabled. + If "false", the vport is to be enabled. When a request is made to change the disabled state on a vport, the transport will validate the request against the existing vport state. @@ -404,7 +404,7 @@ Vport Deletion: int vport_delete(struct fc_vport *vport) where: - vport: Is vport to delete + vport: Is vport to delete When a request is made to delete a vport (via sgio/netlink, or via the fc_host or fc_vport vport_delete attributes), the transport will call diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c index 2176514681..4953f0dca0 100644 --- a/drivers/scsi/scsi_transport_fc.c +++ b/drivers/scsi/scsi_transport_fc.c @@ -1,4 +1,4 @@ -/* +/* * FiberChannel transport specific attributes exported to sysfs. * * Copyright (c) 2003 Silicon Graphics, Inc. All rights reserved. @@ -22,6 +22,7 @@ * Copyright (C) 2004-2007 James Smart, Emulex Corporation * Rewrite for host, target, device, and remote port attributes, * statistics, and service functions... + * Add vports, etc * */ #include @@ -37,6 +38,7 @@ #include "scsi_priv.h" static int fc_queue_work(struct Scsi_Host *, struct work_struct *); +static void fc_vport_sched_delete(struct work_struct *work); /* * This is a temporary carrier for creating a vport. It will eventually @@ -377,7 +379,7 @@ static int fc_host_setup(struct transport_container *tc, struct device *dev, struct Scsi_Host *shost = dev_to_shost(dev); struct fc_host_attrs *fc_host = shost_to_fc_host(shost); - /* + /* * Set default values easily detected by the midlayer as * failure cases. The scsi lldd is responsible for initializing * all transport attributes to valid values per host. @@ -1198,12 +1200,9 @@ store_fc_vport_delete(struct class_device *cdev, const char *buf, size_t count) { struct fc_vport *vport = transport_class_to_vport(cdev); - int stat; - - stat = fc_vport_terminate(vport); - if (stat) - return stat; + struct Scsi_Host *shost = vport_to_shost(vport); + fc_queue_work(shost, &vport->vport_delete_work); return count; } static FC_CLASS_DEVICE_ATTR(vport, vport_delete, S_IWUSR, @@ -1996,7 +1995,7 @@ fc_attach_transport(struct fc_function_template *ft) i->t.eh_timed_out = fc_timed_out; i->t.user_scan = fc_user_scan; - + /* * Setup SCSI Target Attributes. */ @@ -2215,23 +2214,12 @@ fc_remove_host(struct Scsi_Host *shost) struct workqueue_struct *work_q; struct fc_host_attrs *fc_host = shost_to_fc_host(shost); unsigned long flags; - int stat; spin_lock_irqsave(shost->host_lock, flags); /* Remove any vports */ - list_for_each_entry_safe(vport, next_vport, &fc_host->vports, peers) { - spin_unlock_irqrestore(shost->host_lock, flags); - /* this must be called synchronously */ - stat = fc_vport_terminate(vport); - spin_lock_irqsave(shost->host_lock, flags); - if (stat) - dev_printk(KERN_ERR, vport->dev.parent, - "%s: %s could not be deleted created via " - "shost%d channel %d\n", __FUNCTION__, - vport->dev.bus_id, vport->shost->host_no, - vport->channel); - } + list_for_each_entry_safe(vport, next_vport, &fc_host->vports, peers) + fc_queue_work(shost, &vport->vport_delete_work); /* Remove any remote ports */ list_for_each_entry_safe(rport, next_rport, @@ -2308,7 +2296,7 @@ fc_rport_final_delete(struct work_struct *work) unsigned long flags; /* - * if a scan is pending, flush the SCSI Host work_q so that + * if a scan is pending, flush the SCSI Host work_q so that * that we can reclaim the rport scan work element. */ if (rport->flags & FC_RPORT_SCAN_PENDING) @@ -2858,7 +2846,7 @@ EXPORT_SYMBOL(fc_remote_port_rolechg); * fc_timeout_deleted_rport - Timeout handler for a deleted remote port, * which we blocked, and has now failed to return * in the allotted time. - * + * * @work: rport target that failed to reappear in the allotted time. **/ static void @@ -3061,6 +3049,7 @@ fc_vport_create(struct Scsi_Host *shost, int channel, struct device *pdev, vport->shost = shost; vport->channel = channel; vport->flags = FC_VPORT_CREATING; + INIT_WORK(&vport->vport_delete_work, fc_vport_sched_delete); spin_lock_irqsave(shost->host_lock, flags); @@ -3207,8 +3196,30 @@ fc_vport_terminate(struct fc_vport *vport) } EXPORT_SYMBOL(fc_vport_terminate); +/** + * fc_vport_sched_delete - workq-based delete request for a vport + * + * @work: vport to be deleted. + **/ +static void +fc_vport_sched_delete(struct work_struct *work) +{ + struct fc_vport *vport = + container_of(work, struct fc_vport, vport_delete_work); + int stat; + + stat = fc_vport_terminate(vport); + if (stat) + dev_printk(KERN_ERR, vport->dev.parent, + "%s: %s could not be deleted created via " + "shost%d channel %d - error %d\n", __FUNCTION__, + vport->dev.bus_id, vport->shost->host_no, + vport->channel, stat); +} + -MODULE_AUTHOR("Martin Hicks"); +/* Original Author: Martin Hicks */ +MODULE_AUTHOR("James Smart"); MODULE_DESCRIPTION("FC Transport Attributes"); MODULE_LICENSE("GPL"); diff --git a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h index 81ea7b4bf8..a0d80bcaa9 100644 --- a/include/scsi/scsi_transport_fc.h +++ b/include/scsi/scsi_transport_fc.h @@ -1,4 +1,4 @@ -/* +/* * FiberChannel transport specific attributes exported to sysfs. * * Copyright (c) 2003 Silicon Graphics, Inc. All rights reserved. @@ -104,7 +104,7 @@ enum fc_vport_state { -/* +/* * FC Classes of Service * Note: values are not enumerated, as they can be "or'd" together * for reporting (e.g. report supported_classes). If you alter this list, @@ -117,7 +117,7 @@ enum fc_vport_state { #define FC_COS_CLASS4 0x10 #define FC_COS_CLASS6 0x40 -/* +/* * FC Port Speeds * Note: values are not enumerated, as they can be "or'd" together * for reporting (e.g. report supported_speeds). If you alter this list, @@ -223,6 +223,7 @@ struct fc_vport { u8 flags; struct list_head peers; struct device dev; + struct work_struct vport_delete_work; } __attribute__((aligned(sizeof(unsigned long)))); /* bit field values for struct fc_vport "flags" field: */ @@ -397,7 +398,7 @@ struct fc_host_statistics { u64 prim_seq_protocol_err_count; u64 invalid_tx_word_count; u64 invalid_crc_count; - + /* fc4 statistics (only FCP supported currently) */ u64 fcp_input_requests; u64 fcp_output_requests; @@ -592,11 +593,11 @@ struct fc_function_template { u32 dd_fcrport_size; u32 dd_fcvport_size; - /* + /* * The driver sets these to tell the transport class it * wants the attributes displayed in sysfs. If the show_ flag * is not set, the attribute will be private to the transport - * class + * class */ /* remote port fixed attributes */