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| author | Damien Le Moal <damien.lemoal@wdc.com> | 2017-08-09 06:00:22 +0300 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2017-08-17 03:01:31 +0300 |
| commit | 70e42fd02c46e2aa9ab07b766d418637e3a51de7 (patch) | |
| tree | 2f59f796eb5a19d660f3277869042a9bf144d52a /include/scsi/scsi_cmnd.h | |
| parent | c80267324938a5517fd31fa4bbd2d63c564401f9 (diff) | |
| download | linux-70e42fd02c46e2aa9ab07b766d418637e3a51de7.tar.xz | |
scsi: sd_zbc: Write unlock zone from sd_uninit_cmnd()
Releasing a zone write lock only when the write commnand that acquired
the lock completes can cause deadlocks due to potential command
reordering if the lock owning request is requeued and not executed. This
problem exists only with the scsi-mq path as, unlike the legacy path,
requests are moved out of the dispatch queue before being prepared and
so before locking a zone for a write command.
Since sd_uninit_cmnd() is now always called when a request is requeued,
call sd_zbc_write_unlock_zone() from that function for write requests
that acquired a zone lock instead of from sd_done(). Acquisition of a zone
lock by a write command is indicated using the new command
flag SCMD_ZONE_WRITE_LOCK.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'include/scsi/scsi_cmnd.h')
| -rw-r--r-- | include/scsi/scsi_cmnd.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h index a1266d318c85..6af198d8120b 100644 --- a/include/scsi/scsi_cmnd.h +++ b/include/scsi/scsi_cmnd.h @@ -57,6 +57,7 @@ struct scsi_pointer { /* for scmd->flags */ #define SCMD_TAGGED (1 << 0) #define SCMD_UNCHECKED_ISA_DMA (1 << 1) +#define SCMD_ZONE_WRITE_LOCK (1 << 2) struct scsi_cmnd { struct scsi_request req; |