]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - c_src/libbcachefs/chardev.c
move Rust sources to top level, C sources into c_src
[bcachefs-tools-debian] / c_src / libbcachefs / chardev.c
diff --git a/c_src/libbcachefs/chardev.c b/c_src/libbcachefs/chardev.c
new file mode 100644 (file)
index 0000000..226b39c
--- /dev/null
@@ -0,0 +1,999 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef NO_BCACHEFS_CHARDEV
+
+#include "bcachefs.h"
+#include "bcachefs_ioctl.h"
+#include "buckets.h"
+#include "chardev.h"
+#include "journal.h"
+#include "move.h"
+#include "recovery.h"
+#include "replicas.h"
+#include "super.h"
+#include "super-io.h"
+#include "thread_with_file.h"
+
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/ioctl.h>
+#include <linux/major.h>
+#include <linux/sched/task.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+
+__must_check
+static int copy_to_user_errcode(void __user *to, const void *from, unsigned long n)
+{
+       return copy_to_user(to, from, n) ? -EFAULT : 0;
+}
+
+/* returns with ref on ca->ref */
+static struct bch_dev *bch2_device_lookup(struct bch_fs *c, u64 dev,
+                                         unsigned flags)
+{
+       struct bch_dev *ca;
+
+       if (flags & BCH_BY_INDEX) {
+               if (dev >= c->sb.nr_devices)
+                       return ERR_PTR(-EINVAL);
+
+               rcu_read_lock();
+               ca = rcu_dereference(c->devs[dev]);
+               if (ca)
+                       percpu_ref_get(&ca->ref);
+               rcu_read_unlock();
+
+               if (!ca)
+                       return ERR_PTR(-EINVAL);
+       } else {
+               char *path;
+
+               path = strndup_user((const char __user *)
+                                   (unsigned long) dev, PATH_MAX);
+               if (IS_ERR(path))
+                       return ERR_CAST(path);
+
+               ca = bch2_dev_lookup(c, path);
+               kfree(path);
+       }
+
+       return ca;
+}
+
+#if 0
+static long bch2_ioctl_assemble(struct bch_ioctl_assemble __user *user_arg)
+{
+       struct bch_ioctl_assemble arg;
+       struct bch_fs *c;
+       u64 *user_devs = NULL;
+       char **devs = NULL;
+       unsigned i;
+       int ret = -EFAULT;
+
+       if (copy_from_user(&arg, user_arg, sizeof(arg)))
+               return -EFAULT;
+
+       if (arg.flags || arg.pad)
+               return -EINVAL;
+
+       user_devs = kmalloc_array(arg.nr_devs, sizeof(u64), GFP_KERNEL);
+       if (!user_devs)
+               return -ENOMEM;
+
+       devs = kcalloc(arg.nr_devs, sizeof(char *), GFP_KERNEL);
+
+       if (copy_from_user(user_devs, user_arg->devs,
+                          sizeof(u64) * arg.nr_devs))
+               goto err;
+
+       for (i = 0; i < arg.nr_devs; i++) {
+               devs[i] = strndup_user((const char __user *)(unsigned long)
+                                      user_devs[i],
+                                      PATH_MAX);
+               ret= PTR_ERR_OR_ZERO(devs[i]);
+               if (ret)
+                       goto err;
+       }
+
+       c = bch2_fs_open(devs, arg.nr_devs, bch2_opts_empty());
+       ret = PTR_ERR_OR_ZERO(c);
+       if (!ret)
+               closure_put(&c->cl);
+err:
+       if (devs)
+               for (i = 0; i < arg.nr_devs; i++)
+                       kfree(devs[i]);
+       kfree(devs);
+       return ret;
+}
+
+static long bch2_ioctl_incremental(struct bch_ioctl_incremental __user *user_arg)
+{
+       struct bch_ioctl_incremental arg;
+       const char *err;
+       char *path;
+
+       if (copy_from_user(&arg, user_arg, sizeof(arg)))
+               return -EFAULT;
+
+       if (arg.flags || arg.pad)
+               return -EINVAL;
+
+       path = strndup_user((const char __user *)(unsigned long) arg.dev, PATH_MAX);
+       ret = PTR_ERR_OR_ZERO(path);
+       if (ret)
+               return ret;
+
+       err = bch2_fs_open_incremental(path);
+       kfree(path);
+
+       if (err) {
+               pr_err("Could not register bcachefs devices: %s", err);
+               return -EINVAL;
+       }
+
+       return 0;
+}
+#endif
+
+struct fsck_thread {
+       struct thread_with_stdio thr;
+       struct bch_fs           *c;
+       char                    **devs;
+       size_t                  nr_devs;
+       struct bch_opts         opts;
+};
+
+static void bch2_fsck_thread_exit(struct thread_with_stdio *_thr)
+{
+       struct fsck_thread *thr = container_of(_thr, struct fsck_thread, thr);
+       if (thr->devs)
+               for (size_t i = 0; i < thr->nr_devs; i++)
+                       kfree(thr->devs[i]);
+       kfree(thr->devs);
+       kfree(thr);
+}
+
+static int bch2_fsck_offline_thread_fn(void *arg)
+{
+       struct fsck_thread *thr = container_of(arg, struct fsck_thread, thr);
+       struct bch_fs *c = bch2_fs_open(thr->devs, thr->nr_devs, thr->opts);
+
+       thr->thr.thr.ret = PTR_ERR_OR_ZERO(c);
+       if (!thr->thr.thr.ret)
+               bch2_fs_stop(c);
+
+       thread_with_stdio_done(&thr->thr);
+       return 0;
+}
+
+static long bch2_ioctl_fsck_offline(struct bch_ioctl_fsck_offline __user *user_arg)
+{
+       struct bch_ioctl_fsck_offline arg;
+       struct fsck_thread *thr = NULL;
+       u64 *devs = NULL;
+       long ret = 0;
+
+       if (copy_from_user(&arg, user_arg, sizeof(arg)))
+               return -EFAULT;
+
+       if (arg.flags)
+               return -EINVAL;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if (!(devs = kcalloc(arg.nr_devs, sizeof(*devs), GFP_KERNEL)) ||
+           !(thr = kzalloc(sizeof(*thr), GFP_KERNEL)) ||
+           !(thr->devs = kcalloc(arg.nr_devs, sizeof(*thr->devs), GFP_KERNEL))) {
+               ret = -ENOMEM;
+               goto err;
+       }
+
+       thr->opts = bch2_opts_empty();
+       thr->nr_devs = arg.nr_devs;
+
+       if (copy_from_user(devs, &user_arg->devs[0],
+                          array_size(sizeof(user_arg->devs[0]), arg.nr_devs))) {
+               ret = -EINVAL;
+               goto err;
+       }
+
+       for (size_t i = 0; i < arg.nr_devs; i++) {
+               thr->devs[i] = strndup_user((char __user *)(unsigned long) devs[i], PATH_MAX);
+               ret = PTR_ERR_OR_ZERO(thr->devs[i]);
+               if (ret)
+                       goto err;
+       }
+
+       if (arg.opts) {
+               char *optstr = strndup_user((char __user *)(unsigned long) arg.opts, 1 << 16);
+
+               ret =   PTR_ERR_OR_ZERO(optstr) ?:
+                       bch2_parse_mount_opts(NULL, &thr->opts, optstr);
+               kfree(optstr);
+
+               if (ret)
+                       goto err;
+       }
+
+       opt_set(thr->opts, stdio, (u64)(unsigned long)&thr->thr.stdio);
+
+       ret = bch2_run_thread_with_stdio(&thr->thr,
+                       bch2_fsck_thread_exit,
+                       bch2_fsck_offline_thread_fn);
+err:
+       if (ret < 0) {
+               if (thr)
+                       bch2_fsck_thread_exit(&thr->thr);
+               pr_err("ret %s", bch2_err_str(ret));
+       }
+       kfree(devs);
+       return ret;
+}
+
+static long bch2_global_ioctl(unsigned cmd, void __user *arg)
+{
+       long ret;
+
+       switch (cmd) {
+#if 0
+       case BCH_IOCTL_ASSEMBLE:
+               return bch2_ioctl_assemble(arg);
+       case BCH_IOCTL_INCREMENTAL:
+               return bch2_ioctl_incremental(arg);
+#endif
+       case BCH_IOCTL_FSCK_OFFLINE: {
+               ret = bch2_ioctl_fsck_offline(arg);
+               break;
+       }
+       default:
+               ret = -ENOTTY;
+               break;
+       }
+
+       if (ret < 0)
+               ret = bch2_err_class(ret);
+       return ret;
+}
+
+static long bch2_ioctl_query_uuid(struct bch_fs *c,
+                       struct bch_ioctl_query_uuid __user *user_arg)
+{
+       return copy_to_user_errcode(&user_arg->uuid, &c->sb.user_uuid,
+                                   sizeof(c->sb.user_uuid));
+}
+
+#if 0
+static long bch2_ioctl_start(struct bch_fs *c, struct bch_ioctl_start arg)
+{
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if (arg.flags || arg.pad)
+               return -EINVAL;
+
+       return bch2_fs_start(c);
+}
+
+static long bch2_ioctl_stop(struct bch_fs *c)
+{
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       bch2_fs_stop(c);
+       return 0;
+}
+#endif
+
+static long bch2_ioctl_disk_add(struct bch_fs *c, struct bch_ioctl_disk arg)
+{
+       char *path;
+       int ret;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if (arg.flags || arg.pad)
+               return -EINVAL;
+
+       path = strndup_user((const char __user *)(unsigned long) arg.dev, PATH_MAX);
+       ret = PTR_ERR_OR_ZERO(path);
+       if (ret)
+               return ret;
+
+       ret = bch2_dev_add(c, path);
+       kfree(path);
+
+       return ret;
+}
+
+static long bch2_ioctl_disk_remove(struct bch_fs *c, struct bch_ioctl_disk arg)
+{
+       struct bch_dev *ca;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if ((arg.flags & ~(BCH_FORCE_IF_DATA_LOST|
+                          BCH_FORCE_IF_METADATA_LOST|
+                          BCH_FORCE_IF_DEGRADED|
+                          BCH_BY_INDEX)) ||
+           arg.pad)
+               return -EINVAL;
+
+       ca = bch2_device_lookup(c, arg.dev, arg.flags);
+       if (IS_ERR(ca))
+               return PTR_ERR(ca);
+
+       return bch2_dev_remove(c, ca, arg.flags);
+}
+
+static long bch2_ioctl_disk_online(struct bch_fs *c, struct bch_ioctl_disk arg)
+{
+       char *path;
+       int ret;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if (arg.flags || arg.pad)
+               return -EINVAL;
+
+       path = strndup_user((const char __user *)(unsigned long) arg.dev, PATH_MAX);
+       ret = PTR_ERR_OR_ZERO(path);
+       if (ret)
+               return ret;
+
+       ret = bch2_dev_online(c, path);
+       kfree(path);
+       return ret;
+}
+
+static long bch2_ioctl_disk_offline(struct bch_fs *c, struct bch_ioctl_disk arg)
+{
+       struct bch_dev *ca;
+       int ret;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if ((arg.flags & ~(BCH_FORCE_IF_DATA_LOST|
+                          BCH_FORCE_IF_METADATA_LOST|
+                          BCH_FORCE_IF_DEGRADED|
+                          BCH_BY_INDEX)) ||
+           arg.pad)
+               return -EINVAL;
+
+       ca = bch2_device_lookup(c, arg.dev, arg.flags);
+       if (IS_ERR(ca))
+               return PTR_ERR(ca);
+
+       ret = bch2_dev_offline(c, ca, arg.flags);
+       percpu_ref_put(&ca->ref);
+       return ret;
+}
+
+static long bch2_ioctl_disk_set_state(struct bch_fs *c,
+                       struct bch_ioctl_disk_set_state arg)
+{
+       struct bch_dev *ca;
+       int ret;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if ((arg.flags & ~(BCH_FORCE_IF_DATA_LOST|
+                          BCH_FORCE_IF_METADATA_LOST|
+                          BCH_FORCE_IF_DEGRADED|
+                          BCH_BY_INDEX)) ||
+           arg.pad[0] || arg.pad[1] || arg.pad[2] ||
+           arg.new_state >= BCH_MEMBER_STATE_NR)
+               return -EINVAL;
+
+       ca = bch2_device_lookup(c, arg.dev, arg.flags);
+       if (IS_ERR(ca))
+               return PTR_ERR(ca);
+
+       ret = bch2_dev_set_state(c, ca, arg.new_state, arg.flags);
+       if (ret)
+               bch_err(c, "Error setting device state: %s", bch2_err_str(ret));
+
+       percpu_ref_put(&ca->ref);
+       return ret;
+}
+
+struct bch_data_ctx {
+       struct thread_with_file         thr;
+
+       struct bch_fs                   *c;
+       struct bch_ioctl_data           arg;
+       struct bch_move_stats           stats;
+};
+
+static int bch2_data_thread(void *arg)
+{
+       struct bch_data_ctx *ctx = container_of(arg, struct bch_data_ctx, thr);
+
+       ctx->thr.ret = bch2_data_job(ctx->c, &ctx->stats, ctx->arg);
+       ctx->stats.data_type = U8_MAX;
+       return 0;
+}
+
+static int bch2_data_job_release(struct inode *inode, struct file *file)
+{
+       struct bch_data_ctx *ctx = container_of(file->private_data, struct bch_data_ctx, thr);
+
+       bch2_thread_with_file_exit(&ctx->thr);
+       kfree(ctx);
+       return 0;
+}
+
+static ssize_t bch2_data_job_read(struct file *file, char __user *buf,
+                                 size_t len, loff_t *ppos)
+{
+       struct bch_data_ctx *ctx = container_of(file->private_data, struct bch_data_ctx, thr);
+       struct bch_fs *c = ctx->c;
+       struct bch_ioctl_data_event e = {
+               .type                   = BCH_DATA_EVENT_PROGRESS,
+               .p.data_type            = ctx->stats.data_type,
+               .p.btree_id             = ctx->stats.pos.btree,
+               .p.pos                  = ctx->stats.pos.pos,
+               .p.sectors_done         = atomic64_read(&ctx->stats.sectors_seen),
+               .p.sectors_total        = bch2_fs_usage_read_short(c).used,
+       };
+
+       if (len < sizeof(e))
+               return -EINVAL;
+
+       return copy_to_user_errcode(buf, &e, sizeof(e)) ?: sizeof(e);
+}
+
+static const struct file_operations bcachefs_data_ops = {
+       .release        = bch2_data_job_release,
+       .read           = bch2_data_job_read,
+       .llseek         = no_llseek,
+};
+
+static long bch2_ioctl_data(struct bch_fs *c,
+                           struct bch_ioctl_data arg)
+{
+       struct bch_data_ctx *ctx;
+       int ret;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if (arg.op >= BCH_DATA_OP_NR || arg.flags)
+               return -EINVAL;
+
+       ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+       if (!ctx)
+               return -ENOMEM;
+
+       ctx->c = c;
+       ctx->arg = arg;
+
+       ret = bch2_run_thread_with_file(&ctx->thr,
+                       &bcachefs_data_ops,
+                       bch2_data_thread);
+       if (ret < 0)
+               kfree(ctx);
+       return ret;
+}
+
+static long bch2_ioctl_fs_usage(struct bch_fs *c,
+                               struct bch_ioctl_fs_usage __user *user_arg)
+{
+       struct bch_ioctl_fs_usage *arg = NULL;
+       struct bch_replicas_usage *dst_e, *dst_end;
+       struct bch_fs_usage_online *src;
+       u32 replica_entries_bytes;
+       unsigned i;
+       int ret = 0;
+
+       if (!test_bit(BCH_FS_started, &c->flags))
+               return -EINVAL;
+
+       if (get_user(replica_entries_bytes, &user_arg->replica_entries_bytes))
+               return -EFAULT;
+
+       arg = kzalloc(size_add(sizeof(*arg), replica_entries_bytes), GFP_KERNEL);
+       if (!arg)
+               return -ENOMEM;
+
+       src = bch2_fs_usage_read(c);
+       if (!src) {
+               ret = -ENOMEM;
+               goto err;
+       }
+
+       arg->capacity           = c->capacity;
+       arg->used               = bch2_fs_sectors_used(c, src);
+       arg->online_reserved    = src->online_reserved;
+
+       for (i = 0; i < BCH_REPLICAS_MAX; i++)
+               arg->persistent_reserved[i] = src->u.persistent_reserved[i];
+
+       dst_e   = arg->replicas;
+       dst_end = (void *) arg->replicas + replica_entries_bytes;
+
+       for (i = 0; i < c->replicas.nr; i++) {
+               struct bch_replicas_entry_v1 *src_e =
+                       cpu_replicas_entry(&c->replicas, i);
+
+               /* check that we have enough space for one replicas entry */
+               if (dst_e + 1 > dst_end) {
+                       ret = -ERANGE;
+                       break;
+               }
+
+               dst_e->sectors          = src->u.replicas[i];
+               dst_e->r                = *src_e;
+
+               /* recheck after setting nr_devs: */
+               if (replicas_usage_next(dst_e) > dst_end) {
+                       ret = -ERANGE;
+                       break;
+               }
+
+               memcpy(dst_e->r.devs, src_e->devs, src_e->nr_devs);
+
+               dst_e = replicas_usage_next(dst_e);
+       }
+
+       arg->replica_entries_bytes = (void *) dst_e - (void *) arg->replicas;
+
+       percpu_up_read(&c->mark_lock);
+       kfree(src);
+
+       if (ret)
+               goto err;
+
+       ret = copy_to_user_errcode(user_arg, arg,
+                       sizeof(*arg) + arg->replica_entries_bytes);
+err:
+       kfree(arg);
+       return ret;
+}
+
+/* obsolete, didn't allow for new data types: */
+static long bch2_ioctl_dev_usage(struct bch_fs *c,
+                                struct bch_ioctl_dev_usage __user *user_arg)
+{
+       struct bch_ioctl_dev_usage arg;
+       struct bch_dev_usage src;
+       struct bch_dev *ca;
+       unsigned i;
+
+       if (!test_bit(BCH_FS_started, &c->flags))
+               return -EINVAL;
+
+       if (copy_from_user(&arg, user_arg, sizeof(arg)))
+               return -EFAULT;
+
+       if ((arg.flags & ~BCH_BY_INDEX) ||
+           arg.pad[0] ||
+           arg.pad[1] ||
+           arg.pad[2])
+               return -EINVAL;
+
+       ca = bch2_device_lookup(c, arg.dev, arg.flags);
+       if (IS_ERR(ca))
+               return PTR_ERR(ca);
+
+       src = bch2_dev_usage_read(ca);
+
+       arg.state               = ca->mi.state;
+       arg.bucket_size         = ca->mi.bucket_size;
+       arg.nr_buckets          = ca->mi.nbuckets - ca->mi.first_bucket;
+
+       for (i = 0; i < BCH_DATA_NR; i++) {
+               arg.d[i].buckets        = src.d[i].buckets;
+               arg.d[i].sectors        = src.d[i].sectors;
+               arg.d[i].fragmented     = src.d[i].fragmented;
+       }
+
+       percpu_ref_put(&ca->ref);
+
+       return copy_to_user_errcode(user_arg, &arg, sizeof(arg));
+}
+
+static long bch2_ioctl_dev_usage_v2(struct bch_fs *c,
+                                struct bch_ioctl_dev_usage_v2 __user *user_arg)
+{
+       struct bch_ioctl_dev_usage_v2 arg;
+       struct bch_dev_usage src;
+       struct bch_dev *ca;
+       int ret = 0;
+
+       if (!test_bit(BCH_FS_started, &c->flags))
+               return -EINVAL;
+
+       if (copy_from_user(&arg, user_arg, sizeof(arg)))
+               return -EFAULT;
+
+       if ((arg.flags & ~BCH_BY_INDEX) ||
+           arg.pad[0] ||
+           arg.pad[1] ||
+           arg.pad[2])
+               return -EINVAL;
+
+       ca = bch2_device_lookup(c, arg.dev, arg.flags);
+       if (IS_ERR(ca))
+               return PTR_ERR(ca);
+
+       src = bch2_dev_usage_read(ca);
+
+       arg.state               = ca->mi.state;
+       arg.bucket_size         = ca->mi.bucket_size;
+       arg.nr_data_types       = min(arg.nr_data_types, BCH_DATA_NR);
+       arg.nr_buckets          = ca->mi.nbuckets - ca->mi.first_bucket;
+
+       ret = copy_to_user_errcode(user_arg, &arg, sizeof(arg));
+       if (ret)
+               goto err;
+
+       for (unsigned i = 0; i < arg.nr_data_types; i++) {
+               struct bch_ioctl_dev_usage_type t = {
+                       .buckets        = src.d[i].buckets,
+                       .sectors        = src.d[i].sectors,
+                       .fragmented     = src.d[i].fragmented,
+               };
+
+               ret = copy_to_user_errcode(&user_arg->d[i], &t, sizeof(t));
+               if (ret)
+                       goto err;
+       }
+err:
+       percpu_ref_put(&ca->ref);
+       return ret;
+}
+
+static long bch2_ioctl_read_super(struct bch_fs *c,
+                                 struct bch_ioctl_read_super arg)
+{
+       struct bch_dev *ca = NULL;
+       struct bch_sb *sb;
+       int ret = 0;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if ((arg.flags & ~(BCH_BY_INDEX|BCH_READ_DEV)) ||
+           arg.pad)
+               return -EINVAL;
+
+       mutex_lock(&c->sb_lock);
+
+       if (arg.flags & BCH_READ_DEV) {
+               ca = bch2_device_lookup(c, arg.dev, arg.flags);
+
+               if (IS_ERR(ca)) {
+                       ret = PTR_ERR(ca);
+                       goto err;
+               }
+
+               sb = ca->disk_sb.sb;
+       } else {
+               sb = c->disk_sb.sb;
+       }
+
+       if (vstruct_bytes(sb) > arg.size) {
+               ret = -ERANGE;
+               goto err;
+       }
+
+       ret = copy_to_user_errcode((void __user *)(unsigned long)arg.sb, sb,
+                                  vstruct_bytes(sb));
+err:
+       if (!IS_ERR_OR_NULL(ca))
+               percpu_ref_put(&ca->ref);
+       mutex_unlock(&c->sb_lock);
+       return ret;
+}
+
+static long bch2_ioctl_disk_get_idx(struct bch_fs *c,
+                                   struct bch_ioctl_disk_get_idx arg)
+{
+       dev_t dev = huge_decode_dev(arg.dev);
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if (!dev)
+               return -EINVAL;
+
+       for_each_online_member(c, ca)
+               if (ca->dev == dev) {
+                       percpu_ref_put(&ca->io_ref);
+                       return ca->dev_idx;
+               }
+
+       return -BCH_ERR_ENOENT_dev_idx_not_found;
+}
+
+static long bch2_ioctl_disk_resize(struct bch_fs *c,
+                                  struct bch_ioctl_disk_resize arg)
+{
+       struct bch_dev *ca;
+       int ret;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if ((arg.flags & ~BCH_BY_INDEX) ||
+           arg.pad)
+               return -EINVAL;
+
+       ca = bch2_device_lookup(c, arg.dev, arg.flags);
+       if (IS_ERR(ca))
+               return PTR_ERR(ca);
+
+       ret = bch2_dev_resize(c, ca, arg.nbuckets);
+
+       percpu_ref_put(&ca->ref);
+       return ret;
+}
+
+static long bch2_ioctl_disk_resize_journal(struct bch_fs *c,
+                                  struct bch_ioctl_disk_resize_journal arg)
+{
+       struct bch_dev *ca;
+       int ret;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if ((arg.flags & ~BCH_BY_INDEX) ||
+           arg.pad)
+               return -EINVAL;
+
+       if (arg.nbuckets > U32_MAX)
+               return -EINVAL;
+
+       ca = bch2_device_lookup(c, arg.dev, arg.flags);
+       if (IS_ERR(ca))
+               return PTR_ERR(ca);
+
+       ret = bch2_set_nr_journal_buckets(c, ca, arg.nbuckets);
+
+       percpu_ref_put(&ca->ref);
+       return ret;
+}
+
+static int bch2_fsck_online_thread_fn(void *arg)
+{
+       struct fsck_thread *thr = container_of(arg, struct fsck_thread, thr);
+       struct bch_fs *c = thr->c;
+
+       c->stdio_filter = current;
+       c->stdio = &thr->thr.stdio;
+
+       /*
+        * XXX: can we figure out a way to do this without mucking with c->opts?
+        */
+       unsigned old_fix_errors = c->opts.fix_errors;
+       if (opt_defined(thr->opts, fix_errors))
+               c->opts.fix_errors = thr->opts.fix_errors;
+       else
+               c->opts.fix_errors = FSCK_FIX_ask;
+
+       c->opts.fsck = true;
+       set_bit(BCH_FS_fsck_running, &c->flags);
+
+       c->curr_recovery_pass = BCH_RECOVERY_PASS_check_alloc_info;
+       int ret = bch2_run_online_recovery_passes(c);
+
+       clear_bit(BCH_FS_fsck_running, &c->flags);
+       bch_err_fn(c, ret);
+
+       c->stdio = NULL;
+       c->stdio_filter = NULL;
+       c->opts.fix_errors = old_fix_errors;
+
+       thread_with_stdio_done(&thr->thr);
+
+       up(&c->online_fsck_mutex);
+       bch2_ro_ref_put(c);
+       return 0;
+}
+
+static long bch2_ioctl_fsck_online(struct bch_fs *c,
+                                  struct bch_ioctl_fsck_online arg)
+{
+       struct fsck_thread *thr = NULL;
+       long ret = 0;
+
+       if (arg.flags)
+               return -EINVAL;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
+
+       if (!bch2_ro_ref_tryget(c))
+               return -EROFS;
+
+       if (down_trylock(&c->online_fsck_mutex)) {
+               bch2_ro_ref_put(c);
+               return -EAGAIN;
+       }
+
+       thr = kzalloc(sizeof(*thr), GFP_KERNEL);
+       if (!thr) {
+               ret = -ENOMEM;
+               goto err;
+       }
+
+       thr->c = c;
+       thr->opts = bch2_opts_empty();
+
+       if (arg.opts) {
+               char *optstr = strndup_user((char __user *)(unsigned long) arg.opts, 1 << 16);
+
+               ret =   PTR_ERR_OR_ZERO(optstr) ?:
+                       bch2_parse_mount_opts(c, &thr->opts, optstr);
+               kfree(optstr);
+
+               if (ret)
+                       goto err;
+       }
+
+       ret = bch2_run_thread_with_stdio(&thr->thr,
+                       bch2_fsck_thread_exit,
+                       bch2_fsck_online_thread_fn);
+err:
+       if (ret < 0) {
+               bch_err_fn(c, ret);
+               if (thr)
+                       bch2_fsck_thread_exit(&thr->thr);
+               up(&c->online_fsck_mutex);
+               bch2_ro_ref_put(c);
+       }
+       return ret;
+}
+
+#define BCH_IOCTL(_name, _argtype)                                     \
+do {                                                                   \
+       _argtype i;                                                     \
+                                                                       \
+       if (copy_from_user(&i, arg, sizeof(i)))                         \
+               return -EFAULT;                                         \
+       ret = bch2_ioctl_##_name(c, i);                                 \
+       goto out;                                                       \
+} while (0)
+
+long bch2_fs_ioctl(struct bch_fs *c, unsigned cmd, void __user *arg)
+{
+       long ret;
+
+       switch (cmd) {
+       case BCH_IOCTL_QUERY_UUID:
+               return bch2_ioctl_query_uuid(c, arg);
+       case BCH_IOCTL_FS_USAGE:
+               return bch2_ioctl_fs_usage(c, arg);
+       case BCH_IOCTL_DEV_USAGE:
+               return bch2_ioctl_dev_usage(c, arg);
+       case BCH_IOCTL_DEV_USAGE_V2:
+               return bch2_ioctl_dev_usage_v2(c, arg);
+#if 0
+       case BCH_IOCTL_START:
+               BCH_IOCTL(start, struct bch_ioctl_start);
+       case BCH_IOCTL_STOP:
+               return bch2_ioctl_stop(c);
+#endif
+       case BCH_IOCTL_READ_SUPER:
+               BCH_IOCTL(read_super, struct bch_ioctl_read_super);
+       case BCH_IOCTL_DISK_GET_IDX:
+               BCH_IOCTL(disk_get_idx, struct bch_ioctl_disk_get_idx);
+       }
+
+       if (!test_bit(BCH_FS_started, &c->flags))
+               return -EINVAL;
+
+       switch (cmd) {
+       case BCH_IOCTL_DISK_ADD:
+               BCH_IOCTL(disk_add, struct bch_ioctl_disk);
+       case BCH_IOCTL_DISK_REMOVE:
+               BCH_IOCTL(disk_remove, struct bch_ioctl_disk);
+       case BCH_IOCTL_DISK_ONLINE:
+               BCH_IOCTL(disk_online, struct bch_ioctl_disk);
+       case BCH_IOCTL_DISK_OFFLINE:
+               BCH_IOCTL(disk_offline, struct bch_ioctl_disk);
+       case BCH_IOCTL_DISK_SET_STATE:
+               BCH_IOCTL(disk_set_state, struct bch_ioctl_disk_set_state);
+       case BCH_IOCTL_DATA:
+               BCH_IOCTL(data, struct bch_ioctl_data);
+       case BCH_IOCTL_DISK_RESIZE:
+               BCH_IOCTL(disk_resize, struct bch_ioctl_disk_resize);
+       case BCH_IOCTL_DISK_RESIZE_JOURNAL:
+               BCH_IOCTL(disk_resize_journal, struct bch_ioctl_disk_resize_journal);
+       case BCH_IOCTL_FSCK_ONLINE:
+               BCH_IOCTL(fsck_online, struct bch_ioctl_fsck_online);
+       default:
+               return -ENOTTY;
+       }
+out:
+       if (ret < 0)
+               ret = bch2_err_class(ret);
+       return ret;
+}
+
+static DEFINE_IDR(bch_chardev_minor);
+
+static long bch2_chardev_ioctl(struct file *filp, unsigned cmd, unsigned long v)
+{
+       unsigned minor = iminor(file_inode(filp));
+       struct bch_fs *c = minor < U8_MAX ? idr_find(&bch_chardev_minor, minor) : NULL;
+       void __user *arg = (void __user *) v;
+
+       return c
+               ? bch2_fs_ioctl(c, cmd, arg)
+               : bch2_global_ioctl(cmd, arg);
+}
+
+static const struct file_operations bch_chardev_fops = {
+       .owner          = THIS_MODULE,
+       .unlocked_ioctl = bch2_chardev_ioctl,
+       .open           = nonseekable_open,
+};
+
+static int bch_chardev_major;
+static struct class *bch_chardev_class;
+static struct device *bch_chardev;
+
+void bch2_fs_chardev_exit(struct bch_fs *c)
+{
+       if (!IS_ERR_OR_NULL(c->chardev))
+               device_unregister(c->chardev);
+       if (c->minor >= 0)
+               idr_remove(&bch_chardev_minor, c->minor);
+}
+
+int bch2_fs_chardev_init(struct bch_fs *c)
+{
+       c->minor = idr_alloc(&bch_chardev_minor, c, 0, 0, GFP_KERNEL);
+       if (c->minor < 0)
+               return c->minor;
+
+       c->chardev = device_create(bch_chardev_class, NULL,
+                                  MKDEV(bch_chardev_major, c->minor), c,
+                                  "bcachefs%u-ctl", c->minor);
+       if (IS_ERR(c->chardev))
+               return PTR_ERR(c->chardev);
+
+       return 0;
+}
+
+void bch2_chardev_exit(void)
+{
+       if (!IS_ERR_OR_NULL(bch_chardev_class))
+               device_destroy(bch_chardev_class,
+                              MKDEV(bch_chardev_major, U8_MAX));
+       if (!IS_ERR_OR_NULL(bch_chardev_class))
+               class_destroy(bch_chardev_class);
+       if (bch_chardev_major > 0)
+               unregister_chrdev(bch_chardev_major, "bcachefs");
+}
+
+int __init bch2_chardev_init(void)
+{
+       bch_chardev_major = register_chrdev(0, "bcachefs-ctl", &bch_chardev_fops);
+       if (bch_chardev_major < 0)
+               return bch_chardev_major;
+
+       bch_chardev_class = class_create("bcachefs");
+       if (IS_ERR(bch_chardev_class))
+               return PTR_ERR(bch_chardev_class);
+
+       bch_chardev = device_create(bch_chardev_class, NULL,
+                                   MKDEV(bch_chardev_major, U8_MAX),
+                                   NULL, "bcachefs-ctl");
+       if (IS_ERR(bch_chardev))
+               return PTR_ERR(bch_chardev);
+
+       return 0;
+}
+
+#endif /* NO_BCACHEFS_CHARDEV */