diff options
| author | Martin K. Petersen <martin.petersen@oracle.com> | 2024-02-13 09:33:06 -0500 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2024-02-14 12:46:47 -0500 |
| commit | 321da3dc1f3c92a12e3c5da934090d2992a8814c (patch) | |
| tree | b4fd7d2304a909ce22a2d750167f4afa8476bd75 /include | |
| parent | 379a58caa19930e010b7efa1c1f3b9411d3d2ca3 (diff) | |
scsi: sd: usb_storage: uas: Access media prior to querying device properties
It has been observed that some USB/UAS devices return generic properties
hardcoded in firmware for mode pages for a period of time after a device
has been discovered. The reported properties are either garbage or they do
not accurately reflect the characteristics of the physical storage device
attached in the case of a bridge.
Prior to commit 1e029397d12f ("scsi: sd: Reorganize DIF/DIX code to
avoid calling revalidate twice") we would call revalidate several
times during device discovery. As a result, incorrect values would
eventually get replaced with ones accurately describing the attached
storage. When we did away with the redundant revalidate pass, several
cases were reported where devices reported nonsensical values or would
end up in write-protected state.
An initial attempt at addressing this issue involved introducing a
delayed second revalidate invocation. However, this approach still
left some devices reporting incorrect characteristics.
Tasos Sahanidis debugged the problem further and identified that
introducing a READ operation prior to MODE SENSE fixed the problem and that
it wasn't a timing issue. Issuing a READ appears to cause the devices to
update their state to reflect the actual properties of the storage
media. Device properties like vendor, model, and storage capacity appear to
be correctly reported from the get-go. It is unclear why these devices
defer populating the remaining characteristics.
Match the behavior of a well known commercial operating system and
trigger a READ operation prior to querying device characteristics to
force the device to populate the mode pages.
The additional READ is triggered by a flag set in the USB storage and
UAS drivers. We avoid issuing the READ for other transport classes
since some storage devices identify Linux through our particular
discovery command sequence.
Link: https://lore.kernel.org/r/20240213143306.2194237-1-martin.petersen@oracle.com
Fixes: 1e029397d12f ("scsi: sd: Reorganize DIF/DIX code to avoid calling revalidate twice")
Cc: stable@vger.kernel.org
Reported-by: Tasos Sahanidis <tasos@tasossah.com>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Tasos Sahanidis <tasos@tasossah.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/scsi/scsi_device.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 5ec1e71a09de..01c02cb76ea6 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -208,6 +208,7 @@ struct scsi_device { unsigned use_10_for_rw:1; /* first try 10-byte read / write */ unsigned use_10_for_ms:1; /* first try 10-byte mode sense/select */ unsigned set_dbd_for_ms:1; /* Set "DBD" field in mode sense */ + unsigned read_before_ms:1; /* perform a READ before MODE SENSE */ unsigned no_report_opcodes:1; /* no REPORT SUPPORTED OPERATION CODES */ unsigned no_write_same:1; /* no WRITE SAME command */ unsigned use_16_for_rw:1; /* Use read/write(16) over read/write(10) */ |