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-rw-r--r--fs/bcachefs/bcachefs_ioctl.h310
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diff --git a/fs/bcachefs/bcachefs_ioctl.h b/fs/bcachefs/bcachefs_ioctl.h
new file mode 100644
index 000000000000..c65104ed454a
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+++ b/fs/bcachefs/bcachefs_ioctl.h
@@ -0,0 +1,310 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHEFS_IOCTL_H
+#define _BCACHEFS_IOCTL_H
+
+#include <linux/uuid.h>
+#include <asm/ioctl.h>
+#include "bcachefs_format.h"
+
+/*
+ * Flags common to multiple ioctls:
+ */
+#define BCH_FORCE_IF_DATA_LOST (1 << 0)
+#define BCH_FORCE_IF_METADATA_LOST (1 << 1)
+#define BCH_FORCE_IF_DATA_DEGRADED (1 << 2)
+#define BCH_FORCE_IF_METADATA_DEGRADED (1 << 3)
+
+#define BCH_FORCE_IF_DEGRADED \
+ (BCH_FORCE_IF_DATA_DEGRADED| \
+ BCH_FORCE_IF_METADATA_DEGRADED)
+
+/*
+ * If cleared, ioctl that refer to a device pass it as a pointer to a pathname
+ * (e.g. /dev/sda1); if set, the dev field is the device's index within the
+ * filesystem:
+ */
+#define BCH_BY_INDEX (1 << 4)
+
+/*
+ * For BCH_IOCTL_READ_SUPER: get superblock of a specific device, not filesystem
+ * wide superblock:
+ */
+#define BCH_READ_DEV (1 << 5)
+
+/* global control dev: */
+
+/* These are currently broken, and probably unnecessary: */
+#if 0
+#define BCH_IOCTL_ASSEMBLE _IOW(0xbc, 1, struct bch_ioctl_assemble)
+#define BCH_IOCTL_INCREMENTAL _IOW(0xbc, 2, struct bch_ioctl_incremental)
+
+struct bch_ioctl_assemble {
+ __u32 flags;
+ __u32 nr_devs;
+ __u64 pad;
+ __u64 devs[];
+};
+
+struct bch_ioctl_incremental {
+ __u32 flags;
+ __u64 pad;
+ __u64 dev;
+};
+#endif
+
+/* filesystem ioctls: */
+
+#define BCH_IOCTL_QUERY_UUID _IOR(0xbc, 1, struct bch_ioctl_query_uuid)
+
+/* These only make sense when we also have incremental assembly */
+#if 0
+#define BCH_IOCTL_START _IOW(0xbc, 2, struct bch_ioctl_start)
+#define BCH_IOCTL_STOP _IO(0xbc, 3)
+#endif
+
+#define BCH_IOCTL_DISK_ADD _IOW(0xbc, 4, struct bch_ioctl_disk)
+#define BCH_IOCTL_DISK_REMOVE _IOW(0xbc, 5, struct bch_ioctl_disk)
+#define BCH_IOCTL_DISK_ONLINE _IOW(0xbc, 6, struct bch_ioctl_disk)
+#define BCH_IOCTL_DISK_OFFLINE _IOW(0xbc, 7, struct bch_ioctl_disk)
+#define BCH_IOCTL_DISK_SET_STATE _IOW(0xbc, 8, struct bch_ioctl_disk_set_state)
+#define BCH_IOCTL_DATA _IOW(0xbc, 10, struct bch_ioctl_data)
+#define BCH_IOCTL_USAGE _IOWR(0xbc, 11, struct bch_ioctl_usage)
+#define BCH_IOCTL_READ_SUPER _IOW(0xbc, 12, struct bch_ioctl_read_super)
+#define BCH_IOCTL_DISK_GET_IDX _IOW(0xbc, 13, struct bch_ioctl_disk_get_idx)
+#define BCH_IOCTL_DISK_RESIZE _IOW(0xbc, 13, struct bch_ioctl_disk_resize)
+
+/*
+ * BCH_IOCTL_QUERY_UUID: get filesystem UUID
+ *
+ * Returns user visible UUID, not internal UUID (which may not ever be changed);
+ * the filesystem's sysfs directory may be found under /sys/fs/bcachefs with
+ * this UUID.
+ */
+struct bch_ioctl_query_uuid {
+ __uuid_t uuid;
+};
+
+#if 0
+struct bch_ioctl_start {
+ __u32 flags;
+ __u32 pad;
+};
+#endif
+
+/*
+ * BCH_IOCTL_DISK_ADD: add a new device to an existing filesystem
+ *
+ * The specified device must not be open or in use. On success, the new device
+ * will be an online member of the filesystem just like any other member.
+ *
+ * The device must first be prepared by userspace by formatting with a bcachefs
+ * superblock, which is only used for passing in superblock options/parameters
+ * for that device (in struct bch_member). The new device's superblock should
+ * not claim to be a member of any existing filesystem - UUIDs on it will be
+ * ignored.
+ */
+
+/*
+ * BCH_IOCTL_DISK_REMOVE: permanently remove a member device from a filesystem
+ *
+ * Any data present on @dev will be permanently deleted, and @dev will be
+ * removed from its slot in the filesystem's list of member devices. The device
+ * may be either offline or offline.
+ *
+ * Will fail removing @dev would leave us with insufficient read write devices
+ * or degraded/unavailable data, unless the approprate BCH_FORCE_IF_* flags are
+ * set.
+ */
+
+/*
+ * BCH_IOCTL_DISK_ONLINE: given a disk that is already a member of a filesystem
+ * but is not open (e.g. because we started in degraded mode), bring it online
+ *
+ * all existing data on @dev will be available once the device is online,
+ * exactly as if @dev was present when the filesystem was first mounted
+ */
+
+/*
+ * BCH_IOCTL_DISK_OFFLINE: offline a disk, causing the kernel to close that
+ * block device, without removing it from the filesystem (so it can be brought
+ * back online later)
+ *
+ * Data present on @dev will be unavailable while @dev is offline (unless
+ * replicated), but will still be intact and untouched if @dev is brought back
+ * online
+ *
+ * Will fail (similarly to BCH_IOCTL_DISK_SET_STATE) if offlining @dev would
+ * leave us with insufficient read write devices or degraded/unavailable data,
+ * unless the approprate BCH_FORCE_IF_* flags are set.
+ */
+
+struct bch_ioctl_disk {
+ __u32 flags;
+ __u32 pad;
+ __u64 dev;
+};
+
+/*
+ * BCH_IOCTL_DISK_SET_STATE: modify state of a member device of a filesystem
+ *
+ * @new_state - one of the bch_member_state states (rw, ro, failed,
+ * spare)
+ *
+ * Will refuse to change member state if we would then have insufficient devices
+ * to write to, or if it would result in degraded data (when @new_state is
+ * failed or spare) unless the appropriate BCH_FORCE_IF_* flags are set.
+ */
+struct bch_ioctl_disk_set_state {
+ __u32 flags;
+ __u8 new_state;
+ __u8 pad[3];
+ __u64 dev;
+};
+
+enum bch_data_ops {
+ BCH_DATA_OP_SCRUB = 0,
+ BCH_DATA_OP_REREPLICATE = 1,
+ BCH_DATA_OP_MIGRATE = 2,
+ BCH_DATA_OP_NR = 3,
+};
+
+/*
+ * BCH_IOCTL_DATA: operations that walk and manipulate filesystem data (e.g.
+ * scrub, rereplicate, migrate).
+ *
+ * This ioctl kicks off a job in the background, and returns a file descriptor.
+ * Reading from the file descriptor returns a struct bch_ioctl_data_event,
+ * indicating current progress, and closing the file descriptor will stop the
+ * job. The file descriptor is O_CLOEXEC.
+ */
+struct bch_ioctl_data {
+ __u32 op;
+ __u32 flags;
+
+ struct bpos start;
+ struct bpos end;
+
+ union {
+ struct {
+ __u32 dev;
+ __u32 pad;
+ } migrate;
+ struct {
+ __u64 pad[8];
+ };
+ };
+} __attribute__((packed, aligned(8)));
+
+enum bch_data_event {
+ BCH_DATA_EVENT_PROGRESS = 0,
+ /* XXX: add an event for reporting errors */
+ BCH_DATA_EVENT_NR = 1,
+};
+
+struct bch_ioctl_data_progress {
+ __u8 data_type;
+ __u8 btree_id;
+ __u8 pad[2];
+ struct bpos pos;
+
+ __u64 sectors_done;
+ __u64 sectors_total;
+} __attribute__((packed, aligned(8)));
+
+struct bch_ioctl_data_event {
+ __u8 type;
+ __u8 pad[7];
+ union {
+ struct bch_ioctl_data_progress p;
+ __u64 pad2[15];
+ };
+} __attribute__((packed, aligned(8)));
+
+struct bch_ioctl_dev_usage {
+ __u8 state;
+ __u8 alive;
+ __u8 pad[6];
+ __u32 dev;
+
+ __u32 bucket_size;
+ __u64 nr_buckets;
+
+ __u64 buckets[BCH_DATA_NR];
+ __u64 sectors[BCH_DATA_NR];
+};
+
+struct bch_ioctl_fs_usage {
+ __u64 capacity;
+ __u64 used;
+ __u64 online_reserved;
+ __u64 persistent_reserved[BCH_REPLICAS_MAX];
+ __u64 sectors[BCH_DATA_NR][BCH_REPLICAS_MAX];
+};
+
+/*
+ * BCH_IOCTL_USAGE: query filesystem disk space usage
+ *
+ * Returns disk space usage broken out by data type, number of replicas, and
+ * by component device
+ *
+ * @nr_devices - number of devices userspace allocated space for in @devs
+ *
+ * On success, @fs and @devs will be filled out appropriately and devs[i].alive
+ * will indicate if a device was present in that slot
+ *
+ * Returns -ERANGE if @nr_devices was too small
+ */
+struct bch_ioctl_usage {
+ __u16 nr_devices;
+ __u16 pad[3];
+
+ struct bch_ioctl_fs_usage fs;
+ struct bch_ioctl_dev_usage devs[0];
+};
+
+/*
+ * BCH_IOCTL_READ_SUPER: read filesystem superblock
+ *
+ * Equivalent to reading the superblock directly from the block device, except
+ * avoids racing with the kernel writing the superblock or having to figure out
+ * which block device to read
+ *
+ * @sb - buffer to read into
+ * @size - size of userspace allocated buffer
+ * @dev - device to read superblock for, if BCH_READ_DEV flag is
+ * specified
+ *
+ * Returns -ERANGE if buffer provided is too small
+ */
+struct bch_ioctl_read_super {
+ __u32 flags;
+ __u32 pad;
+ __u64 dev;
+ __u64 size;
+ __u64 sb;
+};
+
+/*
+ * BCH_IOCTL_DISK_GET_IDX: give a path to a block device, query filesystem to
+ * determine if disk is a (online) member - if so, returns device's index
+ *
+ * Returns -ENOENT if not found
+ */
+struct bch_ioctl_disk_get_idx {
+ __u64 dev;
+};
+
+/*
+ * BCH_IOCTL_DISK_RESIZE: resize filesystem on a device
+ *
+ * @dev - member to resize
+ * @nbuckets - new number of buckets
+ */
+struct bch_ioctl_disk_resize {
+ __u32 flags;
+ __u32 pad;
+ __u64 dev;
+ __u64 nbuckets;
+};
+
+#endif /* _BCACHEFS_IOCTL_H */