diff options
Diffstat (limited to 'drivers/target/target_core_device.c')
| -rw-r--r-- | drivers/target/target_core_device.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c index cacd97a8cbd0..da457e25717a 100644 --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -828,6 +828,50 @@ struct se_device *target_alloc_device(struct se_hba *hba, const char *name) return dev; } +/* + * Check if the underlying struct block_device request_queue supports + * the QUEUE_FLAG_DISCARD bit for UNMAP/WRITE_SAME in SCSI + TRIM + * in ATA and we need to set TPE=1 + */ +bool target_configure_unmap_from_queue(struct se_dev_attrib *attrib, + struct request_queue *q, int block_size) +{ + if (!blk_queue_discard(q)) + return false; + + attrib->max_unmap_lba_count = (q->limits.max_discard_sectors << 9) / + block_size; + /* + * Currently hardcoded to 1 in Linux/SCSI code.. + */ + attrib->max_unmap_block_desc_count = 1; + attrib->unmap_granularity = q->limits.discard_granularity / block_size; + attrib->unmap_granularity_alignment = q->limits.discard_alignment / + block_size; + attrib->unmap_zeroes_data = q->limits.discard_zeroes_data; + return true; +} +EXPORT_SYMBOL(target_configure_unmap_from_queue); + +/* + * Convert from blocksize advertised to the initiator to the 512 byte + * units unconditionally used by the Linux block layer. + */ +sector_t target_to_linux_sector(struct se_device *dev, sector_t lb) +{ + switch (dev->dev_attrib.block_size) { + case 4096: + return lb << 3; + case 2048: + return lb << 2; + case 1024: + return lb << 1; + default: + return lb; + } +} +EXPORT_SYMBOL(target_to_linux_sector); + int target_configure_device(struct se_device *dev) { struct se_hba *hba = dev->se_hba; |