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[PATCH 09/12] sd: convert to the atomic queue limits API



Assign all queue limits through a local queue_limits variable and
queue_limits_commit_update so that we can't race updating them from
multiple places, and free the queue when updating them so that
in-progress I/O submissions don't see half-updated limits.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 drivers/scsi/sd.c     | 126 ++++++++++++++++++++++++------------------
 drivers/scsi/sd.h     |   6 +-
 drivers/scsi/sd_zbc.c |  15 ++---
 3 files changed, 84 insertions(+), 63 deletions(-)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 2d08b69154b995..03e67936b27928 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -101,12 +101,13 @@ MODULE_ALIAS_SCSI_DEVICE(TYPE_ZBC);
 
 #define SD_MINORS      16
 
-static void sd_config_discard(struct scsi_disk *, unsigned int);
-static void sd_config_write_same(struct scsi_disk *);
+static void sd_config_discard(struct scsi_disk *sdkp, struct queue_limits *lim,
+               unsigned int mode);
+static void sd_config_write_same(struct scsi_disk *sdkp,
+               struct queue_limits *lim);
 static int  sd_revalidate_disk(struct gendisk *);
 static void sd_unlock_native_capacity(struct gendisk *disk);
 static void sd_shutdown(struct device *);
-static void sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer);
 static void scsi_disk_release(struct device *cdev);
 
 static DEFINE_IDA(sd_index_ida);
@@ -456,7 +457,8 @@ provisioning_mode_store(struct device *dev, struct 
device_attribute *attr,
 {
        struct scsi_disk *sdkp = to_scsi_disk(dev);
        struct scsi_device *sdp = sdkp->device;
-       int mode;
+       struct queue_limits lim;
+       int mode, err;
 
        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
@@ -472,8 +474,13 @@ provisioning_mode_store(struct device *dev, struct 
device_attribute *attr,
        if (mode < 0)
                return -EINVAL;
 
-       sd_config_discard(sdkp, mode);
-
+       lim = queue_limits_start_update(sdkp->disk->queue);
+       sd_config_discard(sdkp, &lim, mode);
+       blk_mq_freeze_queue(sdkp->disk->queue);
+       err = queue_limits_commit_update(sdkp->disk->queue, &lim);
+       blk_mq_unfreeze_queue(sdkp->disk->queue);
+       if (err)
+               return err;
        return count;
 }
 static DEVICE_ATTR_RW(provisioning_mode);
@@ -556,6 +563,7 @@ max_write_same_blocks_store(struct device *dev, struct 
device_attribute *attr,
 {
        struct scsi_disk *sdkp = to_scsi_disk(dev);
        struct scsi_device *sdp = sdkp->device;
+       struct queue_limits lim;
        unsigned long max;
        int err;
 
@@ -577,8 +585,13 @@ max_write_same_blocks_store(struct device *dev, struct 
device_attribute *attr,
                sdkp->max_ws_blocks = max;
        }
 
-       sd_config_write_same(sdkp);
-
+       lim = queue_limits_start_update(sdkp->disk->queue);
+       sd_config_write_same(sdkp, &lim);
+       blk_mq_freeze_queue(sdkp->disk->queue);
+       err = queue_limits_commit_update(sdkp->disk->queue, &lim);
+       blk_mq_unfreeze_queue(sdkp->disk->queue);
+       if (err)
+               return err;
        return count;
 }
 static DEVICE_ATTR_RW(max_write_same_blocks);
@@ -827,17 +840,15 @@ static void sd_disable_discard(struct scsi_disk *sdkp)
        blk_queue_max_discard_sectors(sdkp->disk->queue, 0);
 }
 
-static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
+static void sd_config_discard(struct scsi_disk *sdkp, struct queue_limits *lim,
+               unsigned int mode)
 {
-       struct request_queue *q = sdkp->disk->queue;
        unsigned int logical_block_size = sdkp->device->sector_size;
        unsigned int max_blocks = 0;
 
-       q->limits.discard_alignment =
-               sdkp->unmap_alignment * logical_block_size;
-       q->limits.discard_granularity =
-               max(sdkp->physical_block_size,
-                   sdkp->unmap_granularity * logical_block_size);
+       lim->discard_alignment = sdkp->unmap_alignment * logical_block_size;
+       lim->discard_granularity = max(sdkp->physical_block_size,
+                       sdkp->unmap_granularity * logical_block_size);
        sdkp->provisioning_mode = mode;
 
        switch (mode) {
@@ -875,7 +886,8 @@ static void sd_config_discard(struct scsi_disk *sdkp, 
unsigned int mode)
                break;
        }
 
-       blk_queue_max_discard_sectors(q, max_blocks * (logical_block_size >> 
9));
+       lim->max_hw_discard_sectors = max_blocks *
+               (logical_block_size >> SECTOR_SHIFT);
 }
 
 static void *sd_set_special_bvec(struct request *rq, unsigned int data_len)
@@ -1010,9 +1022,9 @@ static void sd_disable_write_same(struct scsi_disk *sdkp)
        blk_queue_max_write_zeroes_sectors(sdkp->disk->queue, 0);
 }
 
-static void sd_config_write_same(struct scsi_disk *sdkp)
+static void sd_config_write_same(struct scsi_disk *sdkp,
+               struct queue_limits *lim)
 {
-       struct request_queue *q = sdkp->disk->queue;
        unsigned int logical_block_size = sdkp->device->sector_size;
 
        if (sdkp->device->no_write_same) {
@@ -1066,8 +1078,8 @@ static void sd_config_write_same(struct scsi_disk *sdkp)
        }
 
 out:
-       blk_queue_max_write_zeroes_sectors(q, sdkp->max_ws_blocks *
-                                        (logical_block_size >> 9));
+       lim->max_write_zeroes_sectors =
+               sdkp->max_ws_blocks * (logical_block_size >> 9);
 }
 
 static blk_status_t sd_setup_flush_cmnd(struct scsi_cmnd *cmd)
@@ -2523,7 +2535,7 @@ static void read_capacity_error(struct scsi_disk *sdkp, 
struct scsi_device *sdp,
 #define READ_CAPACITY_RETRIES_ON_RESET 10
 
 static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
-                                               unsigned char *buffer)
+               struct queue_limits *lim, unsigned char *buffer)
 {
        unsigned char cmd[16];
        struct scsi_sense_hdr sshdr;
@@ -2597,7 +2609,7 @@ static int read_capacity_16(struct scsi_disk *sdkp, 
struct scsi_device *sdp,
 
        /* Lowest aligned logical block */
        alignment = ((buffer[14] & 0x3f) << 8 | buffer[15]) * sector_size;
-       blk_queue_alignment_offset(sdp->request_queue, alignment);
+       lim->alignment_offset = alignment;
        if (alignment && sdkp->first_scan)
                sd_printk(KERN_NOTICE, sdkp,
                          "physical block alignment offset: %u\n", alignment);
@@ -2608,7 +2620,7 @@ static int read_capacity_16(struct scsi_disk *sdkp, 
struct scsi_device *sdp,
                if (buffer[14] & 0x40) /* LBPRZ */
                        sdkp->lbprz = 1;
 
-               sd_config_discard(sdkp, SD_LBP_WS16);
+               sd_config_discard(sdkp, lim, SD_LBP_WS16);
        }
 
        sdkp->capacity = lba + 1;
@@ -2711,13 +2723,14 @@ static int sd_try_rc16_first(struct scsi_device *sdp)
  * read disk capacity
  */
 static void
-sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer)
+sd_read_capacity(struct scsi_disk *sdkp, struct queue_limits *lim,
+               unsigned char *buffer)
 {
        int sector_size;
        struct scsi_device *sdp = sdkp->device;
 
        if (sd_try_rc16_first(sdp)) {
-               sector_size = read_capacity_16(sdkp, sdp, buffer);
+               sector_size = read_capacity_16(sdkp, sdp, lim, buffer);
                if (sector_size == -EOVERFLOW)
                        goto got_data;
                if (sector_size == -ENODEV)
@@ -2737,7 +2750,7 @@ sd_read_capacity(struct scsi_disk *sdkp, unsigned char 
*buffer)
                        int old_sector_size = sector_size;
                        sd_printk(KERN_NOTICE, sdkp, "Very big device. "
                                        "Trying to use READ CAPACITY(16).\n");
-                       sector_size = read_capacity_16(sdkp, sdp, buffer);
+                       sector_size = read_capacity_16(sdkp, sdp, lim, buffer);
                        if (sector_size < 0) {
                                sd_printk(KERN_NOTICE, sdkp,
                                        "Using 0xffffffff as device size\n");
@@ -2796,9 +2809,8 @@ sd_read_capacity(struct scsi_disk *sdkp, unsigned char 
*buffer)
                 */
                sector_size = 512;
        }
-       blk_queue_logical_block_size(sdp->request_queue, sector_size);
-       blk_queue_physical_block_size(sdp->request_queue,
-                                     sdkp->physical_block_size);
+       lim->logical_block_size = sector_size;
+       lim->physical_block_size = sdkp->physical_block_size;
        sdkp->device->sector_size = sector_size;
 
        if (sdkp->capacity > 0xffffffff)
@@ -3220,11 +3232,11 @@ static unsigned int sd_discard_mode(struct scsi_disk 
*sdkp)
        return SD_LBP_DISABLE;
 }
 
-/**
- * sd_read_block_limits - Query disk device for preferred I/O sizes.
- * @sdkp: disk to query
+/*
+ * Query disk device for preferred I/O sizes.
  */
-static void sd_read_block_limits(struct scsi_disk *sdkp)
+static void sd_read_block_limits(struct scsi_disk *sdkp,
+               struct queue_limits *lim)
 {
        struct scsi_vpd *vpd;
 
@@ -3258,7 +3270,7 @@ static void sd_read_block_limits(struct scsi_disk *sdkp)
                        sdkp->unmap_alignment =
                                get_unaligned_be32(&vpd->data[32]) & ~(1 << 31);
 
-               sd_config_discard(sdkp, sd_discard_mode(sdkp));
+               sd_config_discard(sdkp, lim, sd_discard_mode(sdkp));
        }
 
  out:
@@ -3278,10 +3290,10 @@ static void sd_read_block_limits_ext(struct scsi_disk 
*sdkp)
 }
 
 /**
- * sd_read_block_characteristics - Query block dev. characteristics
- * @sdkp: disk to query
+ * Query block dev. characteristics
  */
-static void sd_read_block_characteristics(struct scsi_disk *sdkp)
+static void sd_read_block_characteristics(struct scsi_disk *sdkp,
+               struct queue_limits *lim)
 {
        struct request_queue *q = sdkp->disk->queue;
        struct scsi_vpd *vpd;
@@ -3307,29 +3319,26 @@ static void sd_read_block_characteristics(struct 
scsi_disk *sdkp)
 
 #ifdef CONFIG_BLK_DEV_ZONED /* sd_probe rejects ZBD devices early otherwise */
        if (sdkp->device->type == TYPE_ZBC) {
-               /*
-                * Host-managed.
-                */
-               disk_set_zoned(sdkp->disk);
+               lim->zoned = true;
 
                /*
                 * Per ZBC and ZAC specifications, writes in sequential write
                 * required zones of host-managed devices must be aligned to
                 * the device physical block size.
                 */
-               blk_queue_zone_write_granularity(q, sdkp->physical_block_size);
+               lim->zone_write_granularity = sdkp->physical_block_size;
        } else {
                /*
                 * Host-aware devices are treated as conventional.
                 */
-               WARN_ON_ONCE(blk_queue_is_zoned(q));
+               lim->zoned = false;
        }
 #endif /* CONFIG_BLK_DEV_ZONED */
 
        if (!sdkp->first_scan)
                return;
 
-       if (blk_queue_is_zoned(q))
+       if (lim->zoned)
                sd_printk(KERN_NOTICE, sdkp, "Host-managed zoned block 
device\n");
        else if (sdkp->zoned == 1)
                sd_printk(KERN_NOTICE, sdkp, "Host-aware SMR disk used as 
regular disk\n");
@@ -3605,8 +3614,10 @@ static int sd_revalidate_disk(struct gendisk *disk)
        struct scsi_device *sdp = sdkp->device;
        struct request_queue *q = sdkp->disk->queue;
        sector_t old_capacity = sdkp->capacity;
+       struct queue_limits lim;
        unsigned char *buffer;
        unsigned int dev_max;
+       int err;
 
        SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp,
                                      "sd_revalidate_disk\n"));
@@ -3627,12 +3638,14 @@ static int sd_revalidate_disk(struct gendisk *disk)
 
        sd_spinup_disk(sdkp);
 
+       lim = queue_limits_start_update(sdkp->disk->queue);
+
        /*
         * Without media there is no reason to ask; moreover, some devices
         * react badly if we do.
         */
        if (sdkp->media_present) {
-               sd_read_capacity(sdkp, buffer);
+               sd_read_capacity(sdkp, &lim, buffer);
                /*
                 * Some USB/UAS devices return generic values for mode pages
                 * until the media has been accessed. Trigger a READ operation
@@ -3651,10 +3664,10 @@ static int sd_revalidate_disk(struct gendisk *disk)
 
                if (scsi_device_supports_vpd(sdp)) {
                        sd_read_block_provisioning(sdkp);
-                       sd_read_block_limits(sdkp);
+                       sd_read_block_limits(sdkp, &lim);
                        sd_read_block_limits_ext(sdkp);
-                       sd_read_block_characteristics(sdkp);
-                       sd_zbc_read_zones(sdkp, buffer);
+                       sd_read_block_characteristics(sdkp, &lim);
+                       sd_zbc_read_zones(sdkp, &lim, buffer);
                        sd_read_cpr(sdkp);
                }
 
@@ -3683,28 +3696,33 @@ static int sd_revalidate_disk(struct gendisk *disk)
        q->limits.max_dev_sectors = logical_to_sectors(sdp, dev_max);
 
        if (sd_validate_min_xfer_size(sdkp))
-               blk_queue_io_min(sdkp->disk->queue,
-                                logical_to_bytes(sdp, sdkp->min_xfer_blocks));
+               lim.io_min = logical_to_bytes(sdp, sdkp->min_xfer_blocks);
        else
-               blk_queue_io_min(sdkp->disk->queue, 0);
+               lim.io_min = 0;
 
        /*
         * Limit default to SCSI host optimal sector limit if set. There may be
         * an impact on performance for when the size of a request exceeds this
         * host limit.
         */
-       q->limits.io_opt = sdp->host->opt_sectors << SECTOR_SHIFT;
+       lim.io_opt = sdp->host->opt_sectors << SECTOR_SHIFT;
        if (sd_validate_opt_xfer_size(sdkp, dev_max)) {
-               q->limits.io_opt = min_not_zero(q->limits.io_opt,
+               lim.io_opt = min_not_zero(lim.io_opt,
                                logical_to_bytes(sdp, sdkp->opt_xfer_blocks));
        }
 
        sdkp->first_scan = 0;
 
        set_capacity_and_notify(disk, logical_to_sectors(sdp, sdkp->capacity));
-       sd_config_write_same(sdkp);
+       sd_config_write_same(sdkp, &lim);
        kfree(buffer);
 
+       blk_mq_freeze_queue(sdkp->disk->queue);
+       err = queue_limits_commit_update(sdkp->disk->queue, &lim);
+       blk_mq_unfreeze_queue(sdkp->disk->queue);
+       if (err)
+               return err;
+
        /*
         * For a zoned drive, revalidating the zones can be done only once
         * the gendisk capacity is set. So if this fails, set back the gendisk
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 49dd600bfa4825..b4170b17bad47a 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -239,7 +239,8 @@ static inline int sd_is_zoned(struct scsi_disk *sdkp)
 
 #ifdef CONFIG_BLK_DEV_ZONED
 
-int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE]);
+int sd_zbc_read_zones(struct scsi_disk *sdkp, struct queue_limits *lim,
+               u8 buf[SD_BUF_SIZE]);
 int sd_zbc_revalidate_zones(struct scsi_disk *sdkp);
 blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd,
                                         unsigned char op, bool all);
@@ -250,7 +251,8 @@ int sd_zbc_report_zones(struct gendisk *disk, sector_t 
sector,
 
 #else /* CONFIG_BLK_DEV_ZONED */
 
-static inline int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 
buf[SD_BUF_SIZE])
+static inline int sd_zbc_read_zones(struct scsi_disk *sdkp,
+               struct queue_limits *lim, u8 buf[SD_BUF_SIZE])
 {
        return 0;
 }
diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index 1c24c844e8d178..f685838d9ed214 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -582,13 +582,15 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
 /**
  * sd_zbc_read_zones - Read zone information and update the request queue
  * @sdkp: SCSI disk pointer.
+ * @lim: queue limits to read into
  * @buf: 512 byte buffer used for storing SCSI command output.
  *
  * Read zone information and update the request queue zone characteristics and
  * also the zoned device information in *sdkp. Called by sd_revalidate_disk()
  * before the gendisk capacity has been set.
  */
-int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE])
+int sd_zbc_read_zones(struct scsi_disk *sdkp, struct queue_limits *lim,
+               u8 buf[SD_BUF_SIZE])
 {
        struct gendisk *disk = sdkp->disk;
        struct request_queue *q = disk->queue;
@@ -626,14 +628,13 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 
buf[SD_BUF_SIZE])
        /* The drive satisfies the kernel restrictions: set it up */
        blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q);
        if (sdkp->zones_max_open == U32_MAX)
-               disk_set_max_open_zones(disk, 0);
+               lim->max_open_zones = 0;
        else
-               disk_set_max_open_zones(disk, sdkp->zones_max_open);
-       disk_set_max_active_zones(disk, 0);
-       blk_queue_chunk_sectors(q,
-                       logical_to_sectors(sdkp->device, zone_blocks));
+               lim->max_open_zones = sdkp->zones_max_open;
+       lim->max_active_zones = 0;
+       lim->chunk_sectors = logical_to_sectors(sdkp->device, zone_blocks);
        /* Enable block layer zone append emulation */
-       blk_queue_max_zone_append_sectors(q, 0);
+       lim->max_zone_append_sectors = 0;
 
        return 0;
 
-- 
2.43.0




 


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