path: root/include/target/target_core_backend.h
diff options
authorNicholas Bellinger <nab@linux-iscsi.org>2013-01-29 22:10:06 -0800
committerNicholas Bellinger <nab@linux-iscsi.org>2013-02-13 11:27:51 -0800
commitd0c8b259f8970d39354c1966853363345d401330 (patch)
treee6739094ba5db9ca88038f0e047e83e82bf21088 /include/target/target_core_backend.h
parentiscsi-target: make some temporary buffers larger (diff)
target/iblock: Use backend REQ_FLUSH hint for WriteCacheEnabled status
This patch allows IBLOCK to check block hints in request_queue->flush_flags when reporting current backend device WriteCacheEnabled status to a remote SCSI initiator port. This is done via a se_subsystem_api->get_write_cache() call instead of a backend se_device creation time flag, as we expect REQ_FLUSH bits to possibly change from an underlying blk_queue_flush() by the SCSI disk driver, or internal raw struct block_device driver usage. Also go ahead and update iblock_execute_rw() bio I/O path code to use REQ_FLUSH + REQ_FUA hints when determining WRITE_FUA usage, and make SPC emulation code use a spc_check_dev_wce() helper to handle both types of cases for virtual backend subsystem drivers. (asias: Drop unnecessary comparsion operators) Reported-by: majianpeng <majianpeng@gmail.com> Cc: majianpeng <majianpeng@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: James Bottomley <JBottomley@Parallels.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'include/target/target_core_backend.h')
1 files changed, 1 insertions, 0 deletions
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 819b0fc45215..f9a80169775d 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -35,6 +35,7 @@ struct se_subsystem_api {
u32 (*get_device_type)(struct se_device *);
sector_t (*get_blocks)(struct se_device *);
unsigned char *(*get_sense_buffer)(struct se_cmd *);
+ bool (*get_write_cache)(struct se_device *);
struct sbc_ops {