diff mbox series

[v6,5/7] ata: libata: Fix FUA handling in ata_build_rw_tf()

Message ID 20221108055544.1481583-6-damien.lemoal@opensource.wdc.com (mailing list archive)
State New, archived
Headers show
Series Improve libata support for FUA | expand

Commit Message

Damien Le Moal Nov. 8, 2022, 5:55 a.m. UTC
If a user issues a write command with the FUA bit set for a device with
NCQ support disabled (that is, the device queue depth was set to 1), the
LBA 48 command WRITE DMA FUA EXT must be used. However,
ata_build_rw_tf() ignores this and first tests if LBA 28 can be used
based on the write command sector and number of blocks. That is, for
small FUA writes at low LBAs, ata_rwcmd_protocol() will cause the write
to fail.

Fix this by preventing the use of LBA 28 for any FUA write request.

Given that the WRITE MULTI FUA EXT command is marked as obsolete in the
ATA specification since ACS-3 (published in 2013), remove the
ATA_CMD_WRITE_MULTI_FUA_EXT command from the ata_rw_cmds array.

Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
---
 drivers/ata/libata-core.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Comments

Christoph Hellwig Nov. 8, 2022, 6:21 a.m. UTC | #1
Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>
Johannes Thumshirn Nov. 8, 2022, 7:44 a.m. UTC | #2
Looks good,
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Niklas Cassel Dec. 30, 2022, 8:57 a.m. UTC | #3
On Tue, Nov 08, 2022 at 02:55:42PM +0900, Damien Le Moal wrote:
> If a user issues a write command with the FUA bit set for a device with
> NCQ support disabled (that is, the device queue depth was set to 1), the
> LBA 48 command WRITE DMA FUA EXT must be used. However,
> ata_build_rw_tf() ignores this and first tests if LBA 28 can be used
> based on the write command sector and number of blocks. That is, for
> small FUA writes at low LBAs, ata_rwcmd_protocol() will cause the write
> to fail.
> 
> Fix this by preventing the use of LBA 28 for any FUA write request.
> 
> Given that the WRITE MULTI FUA EXT command is marked as obsolete in the
> ATA specification since ACS-3 (published in 2013), remove the
> ATA_CMD_WRITE_MULTI_FUA_EXT command from the ata_rw_cmds array.
> 
> Signed-off-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
> ---
>  drivers/ata/libata-core.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index 30adae16efff..2b66fe529d81 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -552,7 +552,7 @@ static const u8 ata_rw_cmds[] = {
>  	0,
>  	0,
>  	0,
> -	ATA_CMD_WRITE_MULTI_FUA_EXT,
> +	0,
>  	/* pio */
>  	ATA_CMD_PIO_READ,
>  	ATA_CMD_PIO_WRITE,
> @@ -727,7 +727,8 @@ int ata_build_rw_tf(struct ata_queued_cmd *qc, u64 block, u32 n_block,
>  	} else if (dev->flags & ATA_DFLAG_LBA) {
>  		tf->flags |= ATA_TFLAG_LBA;
>  
> -		if (lba_28_ok(block, n_block)) {
> +		/* We need LBA48 for FUA writes */
> +		if (!(tf->flags & ATA_TFLAG_FUA) && lba_28_ok(block, n_block)) {
>  			/* use LBA28 */
>  			tf->device |= (block >> 24) & 0xf;
>  		} else if (lba_48_ok(block, n_block)) {
> @@ -742,9 +743,10 @@ int ata_build_rw_tf(struct ata_queued_cmd *qc, u64 block, u32 n_block,
>  			tf->hob_lbah = (block >> 40) & 0xff;
>  			tf->hob_lbam = (block >> 32) & 0xff;
>  			tf->hob_lbal = (block >> 24) & 0xff;
> -		} else
> +		} else {
>  			/* request too large even for LBA48 */
>  			return -ERANGE;
> +		}
>  
>  		if (unlikely(!ata_set_rwcmd_protocol(dev, tf)))
>  			return -EINVAL;
> -- 
> 2.38.1
> 

Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
diff mbox series

Patch

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 30adae16efff..2b66fe529d81 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -552,7 +552,7 @@  static const u8 ata_rw_cmds[] = {
 	0,
 	0,
 	0,
-	ATA_CMD_WRITE_MULTI_FUA_EXT,
+	0,
 	/* pio */
 	ATA_CMD_PIO_READ,
 	ATA_CMD_PIO_WRITE,
@@ -727,7 +727,8 @@  int ata_build_rw_tf(struct ata_queued_cmd *qc, u64 block, u32 n_block,
 	} else if (dev->flags & ATA_DFLAG_LBA) {
 		tf->flags |= ATA_TFLAG_LBA;
 
-		if (lba_28_ok(block, n_block)) {
+		/* We need LBA48 for FUA writes */
+		if (!(tf->flags & ATA_TFLAG_FUA) && lba_28_ok(block, n_block)) {
 			/* use LBA28 */
 			tf->device |= (block >> 24) & 0xf;
 		} else if (lba_48_ok(block, n_block)) {
@@ -742,9 +743,10 @@  int ata_build_rw_tf(struct ata_queued_cmd *qc, u64 block, u32 n_block,
 			tf->hob_lbah = (block >> 40) & 0xff;
 			tf->hob_lbam = (block >> 32) & 0xff;
 			tf->hob_lbal = (block >> 24) & 0xff;
-		} else
+		} else {
 			/* request too large even for LBA48 */
 			return -ERANGE;
+		}
 
 		if (unlikely(!ata_set_rwcmd_protocol(dev, tf)))
 			return -EINVAL;