From: Goffredo Baroncelli <kreij...@inwind.it>
This ioctl is a base for returning / setting information from / to the
fields of the btrfs_dev_item object.
For now only the "type" field is returned / set.
Signed-off-by: Goffredo Baroncelli <kreij...@inwind.it>
---
fs/btrfs/ioctl.c | 68 ++++++++++++++++++++++++++++++++++++++
fs/btrfs/volumes.c | 2 +-
fs/btrfs/volumes.h | 2 ++
include/uapi/linux/btrfs.h | 39 ++++++++++++++++++++++
4 files changed, 110 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index a8c60d46d19c..07898ee3a08d 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4851,6 +4851,72 @@ static int btrfs_ioctl_set_features(struct file *file,
void __user *arg)
return ret;
}
+static long btrfs_ioctl_dev_properties(struct file *file,
+ void __user *argp)
+{
+ struct inode *inode = file_inode(file);
+ struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+ struct btrfs_ioctl_dev_properties dev_props;
+ struct btrfs_device *device;
+ struct btrfs_root *root = fs_info->chunk_root;
+ struct btrfs_trans_handle *trans;
+ int ret;
+ u64 prev_type;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (copy_from_user(&dev_props, argp, sizeof(dev_props)))
+ return -EFAULT;
+
+ device = btrfs_find_device(fs_info->fs_devices, dev_props.devid,
+ NULL, NULL);
+ if (!device) {
+ btrfs_info(fs_info, "change_dev_properties: unable to find
device %llu",
+ dev_props.devid);
+ return -ENODEV;
+ }
+
+ if (dev_props.properties & BTRFS_DEV_PROPERTY_READ) {
+ u64 props = dev_props.properties;
+
+ memset(&dev_props, 0, sizeof(dev_props));
+ if (props & BTRFS_DEV_PROPERTY_TYPE) {
+ dev_props.properties = BTRFS_DEV_PROPERTY_TYPE;
+ dev_props.type = device->type;
+ }
+ if (copy_to_user(argp, &dev_props, sizeof(dev_props)))
+ return -EFAULT;
+ return 0;
+ }
+
+ /* it is possible to set only BTRFS_DEV_PROPERTY_TYPE for now */
+ if (dev_props.properties & ~(BTRFS_DEV_PROPERTY_TYPE))
+ return -EPERM;
+
+ trans = btrfs_start_transaction(root, 1);
+ if (IS_ERR(trans))
+ return PTR_ERR(trans);
+
+ prev_type = device->type;
+ device->type = dev_props.type;
+ ret = btrfs_update_device(trans, device);
+
+ if (ret < 0) {
+ btrfs_abort_transaction(trans, ret);
+ btrfs_end_transaction(trans);
+ device->type = prev_type;
+ return ret;
+ }
+
+ ret = btrfs_commit_transaction(trans);
+ if (ret < 0)
+ device->type = prev_type;
+
+ return ret;
+
+}
+
static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
{
struct btrfs_ioctl_send_args *arg;
@@ -5034,6 +5100,8 @@ long btrfs_ioctl(struct file *file, unsigned int
return btrfs_ioctl_get_subvol_rootref(file, argp);
case BTRFS_IOC_INO_LOOKUP_USER:
return btrfs_ioctl_ino_lookup_user(file, argp);
+ case BTRFS_IOC_DEV_PROPERTIES:
+ return btrfs_ioctl_dev_properties(file, argp);
}
return -ENOTTY;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index b8fab44394f5..0c649b444dcd 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2809,7 +2809,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info,
const char *device_path
return ret;
}
-static noinline int btrfs_update_device(struct btrfs_trans_handle *trans,
+int btrfs_update_device(struct btrfs_trans_handle *trans,
struct btrfs_device *device)
{
int ret;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index d4c3e0dd32b8..0c07b8deecab 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -600,5 +600,7 @@ int btrfs_bg_type_to_factor(u64 flags);
const char *btrfs_bg_type_to_raid_name(u64 flags);
int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
int btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical);
+int btrfs_update_device(struct btrfs_trans_handle *trans,
+ struct btrfs_device *device);
#endif
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 5df73001aad4..bab35d3f819c 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -860,6 +860,43 @@ struct btrfs_ioctl_get_subvol_rootref_args {
__u8 align[7];
};
+#define BTRFS_DEV_PROPERTY_TYPE (1ULL << 0)
+#define BTRFS_DEV_PROPERTY_DEV_GROUP (1ULL << 1)
+#define BTRFS_DEV_PROPERTY_SEEK_SPEED (1ULL << 2)
+#define BTRFS_DEV_PROPERTY_BANDWIDTH (1ULL << 3)
+#define BTRFS_DEV_PROPERTY_READ (1ULL << 60)
+
+/*
+ * The ioctl BTRFS_IOC_DEV_PROPERTIES can read and write the device properties.
+ *
+ * The properties that the user want to write have to be set
+ * in the 'properties' field using the BTRFS_DEV_PROPERTY_xxxx constants.
+ *
+ * If the ioctl is used to read the device properties, the bit
+ * BTRFS_DEV_PROPERTY_READ has to be set in the 'properties' field.
+ * In this case the properties that the user want have to be set in the
+ * 'properties' field. The kernel doesn't return a property that was not
+ * required, however it may return a subset of the requested properties.
+ * The returned properties have the corrispondent BTRFS_DEV_PROPERTY_xxxx
+ * flag set in the 'properties' field.
+ *
+ * Up to 2020/05/11 the only properties that can be read/write is the 'type'
+ * one.
+ */
+struct btrfs_ioctl_dev_properties {
+ __u64 devid;
+ __u64 properties;
+ __u64 type;
+ __u32 dev_group;
+ __u8 seek_speed;
+ __u8 bandwidth;
+
+ /*
+ * for future expansion, pad up to 1k
+ */
+ __u8 reserved[1024-30];
+};
+
/* Error codes as returned by the kernel */
enum btrfs_err_code {
BTRFS_ERROR_DEV_RAID1_MIN_NOT_MET = 1,
@@ -988,5 +1025,7 @@ enum btrfs_err_code {
struct btrfs_ioctl_ino_lookup_user_args)
#define BTRFS_IOC_SNAP_DESTROY_V2 _IOW(BTRFS_IOCTL_MAGIC, 63, \
struct btrfs_ioctl_vol_args_v2)
+#define BTRFS_IOC_DEV_PROPERTIES _IOW(BTRFS_IOCTL_MAGIC, 64, \
+ struct btrfs_ioctl_dev_properties)
#endif /* _UAPI_LINUX_BTRFS_H */
--
2.30.0
