From a357f7b4583ebf81d19c95aef57497ae81c5f63c Mon Sep 17 00:00:00 2001 From: John Garry Date: Wed, 17 Aug 2022 23:20:08 +0800 Subject: ata: libata: Set __ATA_BASE_SHT max_sectors Commit 0568e6122574 ("ata: libata-scsi: cap ata_device->max_sectors according to shost->max_sectors") inadvertently capped the max_sectors value for some SATA disks to a value which is lower than we would want. For a device which supports LBA48, we would previously have request queue max_sectors_kb and max_hw_sectors_kb values of 1280 and 32767 respectively. For AHCI controllers, the value chosen for shost max sectors comes from the minimum of the SCSI host default max sectors in SCSI_DEFAULT_MAX_SECTORS (1024) and the shost DMA device mapping limit. This means that we would now set the max_sectors_kb and max_hw_sectors_kb values for a disk which supports LBA48 at 512, ignoring DMA mapping limit. As report by Oliver at [0], this caused a performance regression. Fix by picking a large enough max sectors value for ATA host controllers such that we don't needlessly reduce max_sectors_kb for LBA48 disks. [0] https://lore.kernel.org/linux-ide/YvsGbidf3na5FpGb@xsang-OptiPlex-9020/T/#m22d9fc5ad15af66066dd9fecf3d50f1b1ef11da3 Fixes: 0568e6122574 ("ata: libata-scsi: cap ata_device->max_sectors according to shost->max_sectors") Reported-by: Oliver Sang Signed-off-by: John Garry Signed-off-by: Damien Le Moal --- include/linux/libata.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/libata.h') diff --git a/include/linux/libata.h b/include/linux/libata.h index 0269ff114f5a..698032e5ef2d 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -1382,7 +1382,8 @@ extern const struct attribute_group *ata_common_sdev_groups[]; .proc_name = drv_name, \ .slave_destroy = ata_scsi_slave_destroy, \ .bios_param = ata_std_bios_param, \ - .unlock_native_capacity = ata_scsi_unlock_native_capacity + .unlock_native_capacity = ata_scsi_unlock_native_capacity,\ + .max_sectors = ATA_MAX_SECTORS_LBA48 #define ATA_SUBBASE_SHT(drv_name) \ __ATA_BASE_SHT(drv_name), \ -- cgit