-- Martin K. Petersen Oracle Linux Engineering From 87441914d491c01b73b949663c101056a9d9b8c7 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" martin.petersen@oracle.com Date: Tue, 13 Feb 2024 09:33:06 -0500 Subject: [PATCH] scsi: sd: usb_storage: uas: Access media prior to querying device properties [ Upstream commit 321da3dc1f3c92a12e3c5da934090d2992a8814c ] 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.co... 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 Signed-off-by: Sasha Levin sashal@kernel.org diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 31b5273f43a7..349b1455a2c6 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3284,6 +3284,24 @@ static bool sd_validate_opt_xfer_size(struct scsi_disk *sdkp, return true; } +static void sd_read_block_zero(struct scsi_disk *sdkp) +{ + unsigned int buf_len = sdkp->device->sector_size; + char *buffer, cmd[10] = { }; + + buffer = kmalloc(buf_len, GFP_KERNEL); + if (!buffer) + return; + + cmd[0] = READ_10; + put_unaligned_be32(0, &cmd[2]); /* Logical block address 0 */ + put_unaligned_be16(1, &cmd[7]); /* Transfer 1 logical block */ + + scsi_execute_req(sdkp->device, cmd, DMA_FROM_DEVICE, buffer, buf_len, + NULL, SD_TIMEOUT, sdkp->max_retries, NULL); + kfree(buffer); +} + /** * sd_revalidate_disk - called the first time a new disk is seen, * performs disk spin up, read_capacity, etc. @@ -3323,7 +3341,13 @@ static int sd_revalidate_disk(struct gendisk *disk) */ if (sdkp->media_present) { sd_read_capacity(sdkp, buffer); - + /* + * Some USB/UAS devices return generic values for mode pages + * until the media has been accessed. Trigger a READ operation + * to force the device to populate mode pages. + */ + if (sdp->read_before_ms) + sd_read_block_zero(sdkp); /* * set the default to rotational. All non-rotational devices * support the block characteristics VPD page, which will diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c index c54e9805da53..12cf9940e5b6 100644 --- a/drivers/usb/storage/scsiglue.c +++ b/drivers/usb/storage/scsiglue.c @@ -179,6 +179,13 @@ static int slave_configure(struct scsi_device *sdev) */ sdev->use_192_bytes_for_3f = 1; + /* + * Some devices report generic values until the media has been + * accessed. Force a READ(10) prior to querying device + * characteristics. + */ + sdev->read_before_ms = 1; + /* * Some devices don't like MODE SENSE with page=0x3f, * which is the command used for checking if a device diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c index de3836412bf3..ed22053b3252 100644 --- a/drivers/usb/storage/uas.c +++ b/drivers/usb/storage/uas.c @@ -878,6 +878,13 @@ static int uas_slave_configure(struct scsi_device *sdev) if (devinfo->flags & US_FL_CAPACITY_HEURISTICS) sdev->guess_capacity = 1; + /* + * Some devices report generic values until the media has been + * accessed. Force a READ(10) prior to querying device + * characteristics. + */ + sdev->read_before_ms = 1; + /* * Some devices don't like MODE SENSE with page=0x3f, * which is the command used for checking if a device diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index d2751ed536df..1504d3137cc6 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -204,6 +204,7 @@ 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) */