linux-dev/drivers/scsi/libfc, branch master

scsi: libfc: Remove get_cpu() semantics in fc_exch_em_alloc()

2022-05-17T01:26:50Z

The get_cpu() in fc_exch_em_alloc() was introduced in commit f018b73af6db ("[SCSI] libfc, libfcoe, fcoe: use smp_processor_id() only when preempt disabled") for no other reason than to simply use smp_processor_id() without getting a warning, because everything is done with the pool->lock held anyway. However, get_cpu(), by disabling preemption, does not play well with PREEMPT_RT, particularly when acquiring a regular (and thus sleepable) spinlock. Therefore remove the get_cpu() and just use the unstable value as we will have CPU locality guarantees next by taking the lock. The window of migration, as noted by Sebastian, is small and even if it happens the result is correct. Link: https://lore.kernel.org/r/20211117025956.79616-2-dave@stgolabs.net Link: https://lore.kernel.org/r/20220506105758.283887-4-bigeasy@linutronix.de Acked-by: Sebastian Andrzej Siewior Signed-off-by: Davidlohr Bueso Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Martin K. Petersen

scsi: fcoe: Use per-CPU API to update per-CPU statistics

2022-05-17T01:26:50Z

The per-CPU statistics (struct fc_stats) is updated by getting a stable per-CPU pointer via get_cpu() + per_cpu_ptr() and then performing the increment. This can be optimized by using this_cpu_*() which will do whatever is needed on the architecture to perform the update safe and efficient. The read out of the individual value (fc_get_host_stats()) should be done by using READ_ONCE() instead of a plain-C access. The difference is that READ_ONCE() will always perform a single access while the plain-C access can be split by the compiler into two loads if it appears beneficial. The usage of u64 has the side-effect that it is also 64bit wide on 32bit architectures and the read is always split into two loads. The can lead to strange values if the read happens during an update which alters both 32bit parts of the 64bit value. This can be circumvented by either using a 32bit variables on 32bit architecures or extending the statistics with a sequence counter. Use this_cpu_*() API to update the statistics and READ_ONCE() to read it. Link: https://lore.kernel.org/r/20220506105758.283887-3-bigeasy@linutronix.de Reviewed-by: Davidlohr Bueso Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Martin K. Petersen

scsi: libfc: Fix use after free in fc_exch_abts_resp()

2022-03-09T03:32:31Z

fc_exch_release(ep) will decrease the ep's reference count. When the reference count reaches zero, it is freed. But ep is still used in the following code, which will lead to a use after free. Return after the fc_exch_release() call to avoid use after free. Link: https://lore.kernel.org/r/20220303015115.459778-1-niejianglei2021@163.com Reviewed-by: Hannes Reinecke Signed-off-by: Jianglei Nie Signed-off-by: Martin K. Petersen

scsi: libfc: Replace one-element arrays with flexible-array members

2022-02-28T02:17:37Z

Use flexible-array members in struct fc_fdmi_attr_entry and fs_fdmi_attrs instead of one-element arrays, and refactor the code accordingly. Also, this helps with the ongoing efforts to globally enable -Warray-bounds and get us closer to being able to tighten the FORTIFY_SOURCE routines on memcpy(). https://github.com/KSPP/linux/issues/79 https://github.com/ClangBuiltLinux/linux/issues/1590 Link: https://lore.kernel.org/r/20220214223903.GA859464@embeddedor Signed-off-by: Gustavo A. R. Silva Signed-off-by: Martin K. Petersen

scsi: libfc: Stop using the SCSI pointer

2022-02-23T02:11:05Z

Move the fc_fcp_pkt pointer, the residual length and the SCSI status into the new data structure libfc_cmd_priv. This patch prepares for removal of the SCSI pointer from struct scsi_cmnd. The user of the libfc data path functions have been identified as follows: $ git grep -lw fc_queuecommand | grep -v scsi/libfc/ drivers/scsi/fcoe/fcoe.c Link: https://lore.kernel.org/r/20220218195117.25689-28-bvanassche@acm.org Cc: Saurav Kashyap Cc: Javed Hasan Reviewed-by: Himanshu Madhani Reviewed-by: Hannes Reinecke Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen

scsi: libfc: Call scsi_done() directly

2021-10-17T01:28:48Z

Conditional statements are faster than indirect calls. Hence call scsi_done() directly. Link: https://lore.kernel.org/r/20211007202923.2174984-44-bvanassche@acm.org Signed-off-by: Bart Van Assche Signed-off-by: Martin K. Petersen

scsi: libfc: Fix array index out of bound exception

2021-06-29T02:31:16Z

Fix array index out of bound exception in fc_rport_prli_resp(). Link: https://lore.kernel.org/r/20210615165939.24327-1-jhasan@marvell.com Signed-off-by: Javed Hasan Signed-off-by: Martin K. Petersen

scsi: libfc: FDMI enhancements

2021-06-10T04:03:56Z

Add all the attributes for FDMI. Fall back mechanism is added in between FDMI V2 and FDMI V1 attributes. In case FDMI get fails for V2 attributes we fall back to V1 attributes. Link: https://lore.kernel.org/r/20210603121623.10084-5-jhasan@marvell.com Reviewed-by: Himanshu Madhani Signed-off-by: Javed Hasan Signed-off-by: Martin K. Petersen

scsi: libfc: Add FDMI-2 attributes

2021-06-10T04:03:56Z

Add all attributes for RHBA and RPA registration. Fallback mechanism is added between RBHA V2 and RHBA V1 attributes. In case RHBA get fails for V2 attributes we fall back to V1 attribute registration. Link: https://lore.kernel.org/r/20210603121623.10084-4-jhasan@marvell.com Reviewed-by: Himanshu Madhani Signed-off-by: Javed Hasan Signed-off-by: Martin K. Petersen

scsi: libfc: Initialisation of RHBA and RPA attributes

2021-06-10T04:03:32Z

Initialize RHBA and RPA attributes. Link: https://lore.kernel.org/r/20210603121623.10084-2-jhasan@marvell.com Reviewed-by: Himanshu Madhani Signed-off-by: Javed Hasan Signed-off-by: Martin K. Petersen