diff options
author | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-01-29 22:10:06 -0800 |
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committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-02-13 11:27:51 -0800 |
commit | d0c8b259f8970d39354c1966853363345d401330 (patch) | |
tree | e6739094ba5db9ca88038f0e047e83e82bf21088 /drivers/target/target_core_spc.c | |
parent | 1be2956d30b2b6200ebb26ffb758ed3c8071303c (diff) | |
download | op-kernel-dev-d0c8b259f8970d39354c1966853363345d401330.zip op-kernel-dev-d0c8b259f8970d39354c1966853363345d401330.tar.gz |
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 'drivers/target/target_core_spc.c')
-rw-r--r-- | drivers/target/target_core_spc.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c index fa24470..8033395 100644 --- a/drivers/target/target_core_spc.c +++ b/drivers/target/target_core_spc.c @@ -407,16 +407,31 @@ check_scsi_name: } EXPORT_SYMBOL(spc_emulate_evpd_83); +static bool +spc_check_dev_wce(struct se_device *dev) +{ + bool wce = false; + + if (dev->transport->get_write_cache) + wce = dev->transport->get_write_cache(dev); + else if (dev->dev_attrib.emulate_write_cache > 0) + wce = true; + + return wce; +} + /* Extended INQUIRY Data VPD Page */ static sense_reason_t spc_emulate_evpd_86(struct se_cmd *cmd, unsigned char *buf) { + struct se_device *dev = cmd->se_dev; + buf[3] = 0x3c; /* Set HEADSUP, ORDSUP, SIMPSUP */ buf[5] = 0x07; /* If WriteCache emulation is enabled, set V_SUP */ - if (cmd->se_dev->dev_attrib.emulate_write_cache > 0) + if (spc_check_dev_wce(dev)) buf[6] = 0x01; return 0; } @@ -766,7 +781,7 @@ static int spc_modesense_caching(struct se_device *dev, u8 pc, u8 *p) if (pc == 1) goto out; - if (dev->dev_attrib.emulate_write_cache > 0) + if (spc_check_dev_wce(dev)) p[2] = 0x04; /* Write Cache Enable */ p[12] = 0x20; /* Disabled Read Ahead */ @@ -878,7 +893,7 @@ static sense_reason_t spc_emulate_modesense(struct se_cmd *cmd) (cmd->se_deve->lun_flags & TRANSPORT_LUNFLAGS_READ_ONLY))) spc_modesense_write_protect(&buf[length], type); - if ((dev->dev_attrib.emulate_write_cache > 0) && + if ((spc_check_dev_wce(dev)) && (dev->dev_attrib.emulate_fua_write > 0)) spc_modesense_dpofua(&buf[length], type); |