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path: root/drivers/target/iscsi/iscsi_target_util.c
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2012-11-16iscsi-target: Fix missed wakeup race in TX threadRoland Dreier1-2/+20
commit d5627acba9ae584cf4928af19f7ddf5f6837de32 upstream. The sleeping code in iscsi_target_tx_thread() is susceptible to the classic missed wakeup race: - TX thread finishes handle_immediate_queue() and handle_response_queue(), thinks both queues are empty. - Another thread adds a queue entry and does wake_up_process(), which does nothing because the TX thread is still awake. - TX thread does schedule_timeout() and sleeps forever. In practice this can kill an iSCSI connection if for example an initiator does single-threaded writes and the target misses the wakeup window when queueing an R2T; in this case the connection will be stuck until the initiator loses patience and does some task management operation (or kills the connection entirely). Fix this by converting to wait_event_interruptible(), which does not suffer from this sort of race. Signed-off-by: Roland Dreier <roland@purestorage.com> Cc: Andy Grover <agrover@redhat.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
2012-02-13iscsi-target: Fix reject release handling in iscsit_free_cmd()Nicholas Bellinger1-0/+11
commit c1ce4bd56f2846de55043374598fd929ad3b711b upstream. This patch addresses a bug where iscsit_free_cmd() was incorrectly calling iscsit_release_cmd() for ISCSI_OP_REJECT because iscsi_add_reject*() will overwrite the original iscsi_cmd->iscsi_opcode assignment. This bug was introduced with the following commit: commit 0be67f2ed8f577d2c72d917928394c5885fa9134 Author: Nicholas Bellinger <nab@linux-iscsi.org> Date: Sun Oct 9 01:48:14 2011 -0700 iscsi-target: Remove SCF_SE_LUN_CMD flag abuses and was manifesting itself as list corruption with the following: [ 131.191092] ------------[ cut here ]------------ [ 131.191092] WARNING: at lib/list_debug.c:53 __list_del_entry+0x8d/0x98() [ 131.191092] Hardware name: VMware Virtual Platform [ 131.191092] list_del corruption. prev->next should be ffff880022d3c100, but was 6b6b6b6b6b6b6b6b [ 131.191092] Modules linked in: tcm_vhost ib_srpt ib_cm ib_sa ib_mad ib_core tcm_qla2xxx qla2xxx tcm_loop tcm_fc libfc scsi_transport_fc crc32c iscsi_target_mod target_core_stgt scsi_tgt target_core_pscsi target_core_file target_core_iblock target_core_mod configfs ipv6 iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi sr_mod cdrom sd_mod e1000 ata_piix libata mptspi mptscsih mptbase [last unloaded: scsi_wait_scan] [ 131.191092] Pid: 2250, comm: iscsi_ttx Tainted: G W 3.2.0-rc4+ #42 [ 131.191092] Call Trace: [ 131.191092] [<ffffffff8103b553>] warn_slowpath_common+0x80/0x98 [ 131.191092] [<ffffffff8103b5ff>] warn_slowpath_fmt+0x41/0x43 [ 131.191092] [<ffffffff811d0279>] __list_del_entry+0x8d/0x98 [ 131.191092] [<ffffffffa01395c9>] transport_lun_remove_cmd+0x9b/0xb7 [target_core_mod] [ 131.191092] [<ffffffffa013a55c>] transport_generic_free_cmd+0x5d/0x71 [target_core_mod] [ 131.191092] [<ffffffffa01a012b>] iscsit_free_cmd+0x1e/0x27 [iscsi_target_mod] [ 131.191092] [<ffffffffa01a13be>] iscsit_close_connection+0x14d/0x5b2 [iscsi_target_mod] [ 131.191092] [<ffffffffa0196a0c>] iscsit_take_action_for_connection_exit+0xdb/0xe0 [iscsi_target_mod] [ 131.191092] [<ffffffffa01a55d4>] iscsi_target_tx_thread+0x15cb/0x1608 [iscsi_target_mod] [ 131.191092] [<ffffffff8103609a>] ? check_preempt_wakeup+0x121/0x185 [ 131.191092] [<ffffffff81030801>] ? __dequeue_entity+0x2e/0x33 [ 131.191092] [<ffffffffa01a4009>] ? iscsit_send_text_rsp+0x25f/0x25f [iscsi_target_mod] [ 131.191092] [<ffffffffa01a4009>] ? iscsit_send_text_rsp+0x25f/0x25f [iscsi_target_mod] [ 131.191092] [<ffffffff8138f706>] ? schedule+0x55/0x57 [ 131.191092] [<ffffffff81056c7d>] kthread+0x7d/0x85 [ 131.191092] [<ffffffff81399534>] kernel_thread_helper+0x4/0x10 [ 131.191092] [<ffffffff81056c00>] ? kthread_worker_fn+0x16d/0x16d [ 131.191092] [<ffffffff81399530>] ? gs_change+0x13/0x13 Reported-by: <jrepac@yahoo.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2011-10-24iscsi-target: Remove SCF_SE_LUN_CMD flag abusesNicholas Bellinger1-0/+17
This patch removes a number of SCF_SE_LUN_CMD flag abuses within iscsi-target code to determine when iscsit_release_cmd() or transport_generic_free_cmd() should be called while releasing an individual iscsi_cmd descriptor. In the place of SCF_SE_LUN_CMD checks, this patch converts existing code to use a new iscsit_free_cmd() that inspects iscsi_cmd->iscsi_opcode types to determine which of the above functions should be invoked. It also removes the now unnecessary special case checking in iscsit_release_commands_from_conn(). (hch: Use iscsit_free_cmd instead of open-coded alternative) Reported-by: Christoph Hellwig <hch@lst.de> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2011-10-24target: Have core_tmr_alloc_req() take an explicit GFP_xxx flagRoland Dreier1-1/+2
Testing in_interrupt() to know when sleeping is allowed is not really reliable (since eg it won't be true if the caller is holding a spinlock). Instead have the caller tell core_tmr_alloc_req() what GFP_xxx to use; every caller except tcm_qla2xxx can use GFP_KERNEL. Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2011-09-17iscsi-target: Fix sendpage breakage with proper padding+DataDigest iovec offsetsNicholas Bellinger1-7/+15
This patch fixes a bug in the iscsit_fe_sendpage_sg() transmit codepath that was originally introduced with the v3.1 iscsi-target merge that incorrectly uses hardcoded cmd->iov_data_count values to determine cmd->iov_data[] offsets for extra outgoing padding and DataDigest payload vectors. This code is obviously incorrect for the DataDigest enabled case with sendpage offload, and this fix ensures correct operation for padding + DataDigest, padding only, and DataDigest only cases. The bug was introduced during a pre-merge change in iscsit_fe_sendpage_sg() to natively use struct scatterlist instead of the legacy v3.0 struct se_mem logic. Cc: Andy Grover <agrover@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2011-09-16iscsi-target: Disable markers + remove dangerous local scope array usageNicholas Bellinger1-242/+6
This patch makes iscsi-target explictly disable OFMarker=Yes and IFMarker=yes parameter key usage during iscsi login by setting IFMarkInt_Reject and OFMarkInt_Reject values in iscsi_enforce_integrity_rules() to effectively disable iscsi marker usage. With this patch, an initiator proposer asking to enable either marker parameter keys will be issued a 'No' response, and the target sets OFMarkInt + IFMarkInt parameter key response to 'Irrelevant'. With markers disabled during iscsi login, this patch removes the problematic on-stack local-scope array for marker intervals in iscsit_do_rx_data() + iscsit_do_tx_data(), and other related marker code in iscsi_target_util.c. This fixes a potentional stack smashing scenario with small range markers enabled and a large MRDSL as reported by DanC here: [bug report] target: stack can be smashed http://www.spinics.net/lists/target-devel/msg00453.html Reported-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2011-08-22iscsi-target: Fix iscsit_allocate_se_cmd_for_tmr failure path bugsDan Carpenter1-3/+1
This patch fixes two bugs in allocation failure handling in iscsit_allocate_se_cmd_for_tmr(): This first reported by DanC is a free-after call to transport_free_se_cmd(), this patch drops the transport_free_se_cmd() call all together, as iscsit_release_cmd() will release existing allocations as expected. The second is a bug where iscsi_cmd_t was being leaked on a cmd->tmr_req allocation failure, so make this jump to iscsit_release_cmd() as well. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2011-07-26iscsi-target: Add iSCSI fabric support for target v4.1Nicholas Bellinger1-0/+1819
The Linux-iSCSI.org target module is a full featured in-kernel software implementation of iSCSI target mode (RFC-3720) for the current WIP mainline target v4.1 infrastructure code for the v3.1 kernel. More information can be found here: http://linux-iscsi.org/wiki/ISCSI This includes support for: * RFC-3720 defined request / response state machines and support for all defined iSCSI operation codes from Section 10.2.1.2 using libiscsi include/scsi/iscsi_proto.h PDU definitions * Target v4.1 compatible control plane using the generic layout in target_core_fabric_configfs.c and fabric dependent attributes within /sys/kernel/config/target/iscsi/ subdirectories. * Target v4.1 compatible iSCSI statistics based on RFC-4544 (iSCSI MIBS) * Support for IPv6 and IPv4 network portals in M:N mapping to TPGs * iSCSI Error Recovery Hierarchy support * Per iSCSI connection RX/TX thread pair scheduling affinity * crc32c + crc32c_intel SSEv4 instruction offload support using libcrypto * CHAP Authentication support using libcrypto * Conversion to use internal SGl allocation with iscsit_alloc_buffs() -> transport_generic_map_mem_to_cmd() (nab: Fix iscsi_proto.h struct scsi_lun usage from linux-next in commit: iscsi: Use struct scsi_lun in iscsi structs instead of u8[8]) (nab: Fix 32-bit compile warnings) Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Andy Grover <agrover@redhat.com> Acked-by: Roland Dreier <roland@kernel.org> Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>