blk-zoned: implement ioctls

Adds the new BLKREPORTZONE and BLKRESETZONE ioctls for respectively
obtaining the zone configuration of a zoned block device and resetting
the write pointer of sequential zones of a zoned block device.

The BLKREPORTZONE ioctl maps directly to a single call of the function
blkdev_report_zones. The zone information result is passed as an array
of struct blk_zone identical to the structure used internally for
processing the REQ_OP_ZONE_REPORT operation.  The BLKRESETZONE ioctl
maps to a single call of the blkdev_reset_zones function.

Signed-off-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Damien Le Moal <damien.lemoal@hgst.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

5 files changed, 162 insertions, 0 deletions

diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 1603573f9605..667f95d86695 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -255,3 +255,96 @@ int blkdev_reset_zones(struct block_device *bdev,
         return 0;
 }
 EXPORT_SYMBOL_GPL(blkdev_reset_zones);
+
+/**
+ * BLKREPORTZONE ioctl processing.
+ * Called from blkdev_ioctl.
+ */
+int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
+                              unsigned int cmd, unsigned long arg)
+{
+        void __user *argp = (void __user *)arg;
+        struct request_queue *q;
+        struct blk_zone_report rep;
+        struct blk_zone *zones;
+        int ret;
+
+        if (!argp)
+                return -EINVAL;
+
+        q = bdev_get_queue(bdev);
+        if (!q)
+                return -ENXIO;
+
+        if (!blk_queue_is_zoned(q))
+                return -ENOTTY;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EACCES;
+
+        if (copy_from_user(&rep, argp, sizeof(struct blk_zone_report)))
+                return -EFAULT;
+
+        if (!rep.nr_zones)
+                return -EINVAL;
+
+        zones = kcalloc(rep.nr_zones, sizeof(struct blk_zone), GFP_KERNEL);
+        if (!zones)
+                return -ENOMEM;
+
+        ret = blkdev_report_zones(bdev, rep.sector,
+                                  zones, &rep.nr_zones,
+                                  GFP_KERNEL);
+        if (ret)
+                goto out;
+
+        if (copy_to_user(argp, &rep, sizeof(struct blk_zone_report))) {
+                ret = -EFAULT;
+                goto out;
+        }
+
+        if (rep.nr_zones) {
+                if (copy_to_user(argp + sizeof(struct blk_zone_report), zones,
+                                 sizeof(struct blk_zone) * rep.nr_zones))
+                        ret = -EFAULT;
+        }
+
+ out:
+        kfree(zones);
+
+        return ret;
+}
+
+/**
+ * BLKRESETZONE ioctl processing.
+ * Called from blkdev_ioctl.
+ */
+int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
+                             unsigned int cmd, unsigned long arg)
+{
+        void __user *argp = (void __user *)arg;
+        struct request_queue *q;
+        struct blk_zone_range zrange;
+
+        if (!argp)
+                return -EINVAL;
+
+        q = bdev_get_queue(bdev);
+        if (!q)
+                return -ENXIO;
+
+        if (!blk_queue_is_zoned(q))
+                return -ENOTTY;
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EACCES;
+
+        if (!(mode & FMODE_WRITE))
+                return -EBADF;
+
+        if (copy_from_user(&zrange, argp, sizeof(struct blk_zone_range)))
+                return -EFAULT;
+
+        return blkdev_reset_zones(bdev, zrange.sector, zrange.nr_sectors,
+                                  GFP_KERNEL);
+}
diff --git a/block/ioctl.c b/block/ioctl.c
index 755119c3c1b9..f856963204f4 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -519,6 +519,10 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
                                 BLKDEV_DISCARD_SECURE);
         case BLKZEROOUT:
                 return blk_ioctl_zeroout(bdev, mode, arg);
+        case BLKREPORTZONE:
+                return blkdev_report_zones_ioctl(bdev, mode, cmd, arg);
+        case BLKRESETZONE:
+                return blkdev_reset_zones_ioctl(bdev, mode, cmd, arg);
         case HDIO_GETGEO:
                 return blkdev_getgeo(bdev, argp);
         case BLKRAGET:
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 252043f7cd2c..90097dd8b8ed 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -316,6 +316,27 @@ extern int blkdev_report_zones(struct block_device *bdev,
 extern int blkdev_reset_zones(struct block_device *bdev, sector_t sectors,
                               sector_t nr_sectors, gfp_t gfp_mask);
 
+extern int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode,
+                                     unsigned int cmd, unsigned long arg);
+extern int blkdev_reset_zones_ioctl(struct block_device *bdev, fmode_t mode,
+                                    unsigned int cmd, unsigned long arg);
+
+#else /* CONFIG_BLK_DEV_ZONED */
+
+static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
+                                            fmode_t mode, unsigned int cmd,
+                                            unsigned long arg)
+{
+        return -ENOTTY;
+}
+
+static inline int blkdev_reset_zones_ioctl(struct block_device *bdev,
+                                           fmode_t mode, unsigned int cmd,
+                                           unsigned long arg)
+{
+        return -ENOTTY;
+}
+
 #endif /* CONFIG_BLK_DEV_ZONED */
 
 struct request_queue {
diff --git a/include/uapi/linux/blkzoned.h b/include/uapi/linux/blkzoned.h
index a3817214b0e0..40d1d7bff537 100644
--- a/include/uapi/linux/blkzoned.h
+++ b/include/uapi/linux/blkzoned.h
@@ -16,6 +16,7 @@
 #define _UAPI_BLKZONED_H
 
 #include <linux/types.h>
+#include <linux/ioctl.h>
 
 /**
  * enum blk_zone_type - Types of zones allowed in a zoned device.
@@ -100,4 +101,43 @@ struct blk_zone {
         __u8    reserved[36];
 };
 
+/**
+ * struct blk_zone_report - BLKREPORTZONE ioctl request/reply
+ *
+ * @sector: starting sector of report
+ * @nr_zones: IN maximum / OUT actual
+ * @reserved: padding to 16 byte alignment
+ * @zones: Space to hold @nr_zones @zones entries on reply.
+ *
+ * The array of at most @nr_zones must follow this structure in memory.
+ */
+struct blk_zone_report {
+        __u64           sector;
+        __u32           nr_zones;
+        __u8            reserved[4];
+        struct blk_zone zones[0];
+} __packed;
+
+/**
+ * struct blk_zone_range - BLKRESETZONE ioctl request
+ * @sector: starting sector of the first zone to issue reset write pointer
+ * @nr_sectors: Total number of sectors of 1 or more zones to reset
+ */
+struct blk_zone_range {
+        __u64           sector;
+        __u64           nr_sectors;
+};
+
+/**
+ * Zoned block device ioctl's:
+ *
+ * @BLKREPORTZONE: Get zone information. Takes a zone report as argument.
+ *                 The zone report will start from the zone containing the
+ *                 sector specified in the report request structure.
+ * @BLKRESETZONE: Reset the write pointer of the zones in the specified
+ *                sector range. The sector range must be zone aligned.
+ */
+#define BLKREPORTZONE   _IOWR(0x12, 130, struct blk_zone_report)
+#define BLKRESETZONE    _IOW(0x12, 131, struct blk_zone_range)
+
 #endif /* _UAPI_BLKZONED_H */
diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
index acb2b6152ba0..c1d11df07b28 100644
--- a/include/uapi/linux/fs.h
+++ b/include/uapi/linux/fs.h
@@ -225,6 +225,10 @@ struct fsxattr {
 #define BLKSECDISCARD _IO(0x12,125)
 #define BLKROTATIONAL _IO(0x12,126)
 #define BLKZEROOUT _IO(0x12,127)
+/*
+ * A jump here: 130-131 are reserved for zoned block devices
+ * (see uapi/linux/blkzoned.h)
+ */
 
 #define BMAP_IOCTL 1            /* obsolete - kept for compatibility */
 #define FIBMAP     _IO(0x00,1)  /* bmap access */