Re: [PATCH v3 6/7] sd: Implement support for ZBC devices
From: "Martin K. Petersen" <martin.petersen@oracle.com>
Date: 2016-09-28 05:01:04
Also in:
linux-scsi
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"Damien" == Damien Le Moal [off-list ref] writes:
Damien, The new stuff looks much cleaner. Thanks for doing that! This hunk has an unintended side effect:
@@ -2836,14 +2896,14 @@ static int sd_revalidate_disk(struct gendisk *disk) * react badly if we do. */ if (sdkp->media_present) { - sd_read_capacity(sdkp, buffer); - if (scsi_device_supports_vpd(sdp)) { sd_read_block_provisioning(sdkp); sd_read_block_limits(sdkp); sd_read_block_characteristics(sdkp); } + sd_read_capacity(sdkp, buffer); + sd_read_write_protect_flag(sdkp, buffer); sd_read_cache_type(sdkp, buffer); sd_read_app_tag_own(sdkp, buffer);
LMBPE from READ CAPACITY(16) will not be set when calling
sd_read_block_provisioning() and thus we bail early (we catch it second
time around). You may want to split that vpd conditional to shuffle the
block_characteristics on top. Or even better: Split the capacity/block
size printing code from sd_read_capacity() into a separate function and
do:
if (sdkp->media_present) {
sd_read_capacity(sdkp, buffer);
if (sd_try_extended_inquiry(sdp)) {
sd_read_block_provisioning(sdkp);
sd_read_block_limits(sdkp);
sd_read_block_characteristics(sdkp);
}
+ sd_print_capacity(sdkp);
sd_read_write_protect_flag(sdkp, buffer);
sd_read_cache_type(sdkp, buffer);
sd_read_app_tag_own(sdkp, buffer);
sd_read_write_same(sdkp, buffer);
}
Typo:
static int sd_zbc_read_zoned_charateristics(struct scsi_disk *sdkp,
^^^^^^^^^^^^^^
My second comment is that I don't particularly like the notion of values
being stored and passed in units of block layer sectors in struct
scsi_disk and sd*. As a rule of thumb I prefer SCSI stuff to be counted
in logical blocks and block layer stuff in 512b sectors. You may want to
entertain having a sectors_to_zone() wrapper to facilitate that
conversion.
--
Martin K. Petersen Oracle Linux Engineering