xref: /linux/fs/bcachefs/bcachefs_ioctl.h (revision 79997eda0d31bc68203c95ecb978773ee6ce7a1f)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _BCACHEFS_IOCTL_H
3 #define _BCACHEFS_IOCTL_H
4 
5 #include <linux/uuid.h>
6 #include <asm/ioctl.h>
7 #include "bcachefs_format.h"
8 
9 /*
10  * Flags common to multiple ioctls:
11  */
12 #define BCH_FORCE_IF_DATA_LOST		(1 << 0)
13 #define BCH_FORCE_IF_METADATA_LOST	(1 << 1)
14 #define BCH_FORCE_IF_DATA_DEGRADED	(1 << 2)
15 #define BCH_FORCE_IF_METADATA_DEGRADED	(1 << 3)
16 
17 #define BCH_FORCE_IF_LOST			\
18 	(BCH_FORCE_IF_DATA_LOST|		\
19 	 BCH_FORCE_IF_METADATA_LOST)
20 #define BCH_FORCE_IF_DEGRADED			\
21 	(BCH_FORCE_IF_DATA_DEGRADED|		\
22 	 BCH_FORCE_IF_METADATA_DEGRADED)
23 
24 /*
25  * If cleared, ioctl that refer to a device pass it as a pointer to a pathname
26  * (e.g. /dev/sda1); if set, the dev field is the device's index within the
27  * filesystem:
28  */
29 #define BCH_BY_INDEX			(1 << 4)
30 
31 /*
32  * For BCH_IOCTL_READ_SUPER: get superblock of a specific device, not filesystem
33  * wide superblock:
34  */
35 #define BCH_READ_DEV			(1 << 5)
36 
37 /* global control dev: */
38 
39 /* These are currently broken, and probably unnecessary: */
40 #if 0
41 #define BCH_IOCTL_ASSEMBLE	_IOW(0xbc, 1, struct bch_ioctl_assemble)
42 #define BCH_IOCTL_INCREMENTAL	_IOW(0xbc, 2, struct bch_ioctl_incremental)
43 
44 struct bch_ioctl_assemble {
45 	__u32			flags;
46 	__u32			nr_devs;
47 	__u64			pad;
48 	__u64			devs[];
49 };
50 
51 struct bch_ioctl_incremental {
52 	__u32			flags;
53 	__u64			pad;
54 	__u64			dev;
55 };
56 #endif
57 
58 /* filesystem ioctls: */
59 
60 #define BCH_IOCTL_QUERY_UUID	_IOR(0xbc,	1,  struct bch_ioctl_query_uuid)
61 
62 /* These only make sense when we also have incremental assembly */
63 #if 0
64 #define BCH_IOCTL_START		_IOW(0xbc,	2,  struct bch_ioctl_start)
65 #define BCH_IOCTL_STOP		_IO(0xbc,	3)
66 #endif
67 
68 #define BCH_IOCTL_DISK_ADD	_IOW(0xbc,	4,  struct bch_ioctl_disk)
69 #define BCH_IOCTL_DISK_REMOVE	_IOW(0xbc,	5,  struct bch_ioctl_disk)
70 #define BCH_IOCTL_DISK_ONLINE	_IOW(0xbc,	6,  struct bch_ioctl_disk)
71 #define BCH_IOCTL_DISK_OFFLINE	_IOW(0xbc,	7,  struct bch_ioctl_disk)
72 #define BCH_IOCTL_DISK_SET_STATE _IOW(0xbc,	8,  struct bch_ioctl_disk_set_state)
73 #define BCH_IOCTL_DATA		_IOW(0xbc,	10, struct bch_ioctl_data)
74 #define BCH_IOCTL_FS_USAGE	_IOWR(0xbc,	11, struct bch_ioctl_fs_usage)
75 #define BCH_IOCTL_DEV_USAGE	_IOWR(0xbc,	11, struct bch_ioctl_dev_usage)
76 #define BCH_IOCTL_READ_SUPER	_IOW(0xbc,	12, struct bch_ioctl_read_super)
77 #define BCH_IOCTL_DISK_GET_IDX	_IOW(0xbc,	13,  struct bch_ioctl_disk_get_idx)
78 #define BCH_IOCTL_DISK_RESIZE	_IOW(0xbc,	14,  struct bch_ioctl_disk_resize)
79 #define BCH_IOCTL_DISK_RESIZE_JOURNAL _IOW(0xbc,15,  struct bch_ioctl_disk_resize_journal)
80 
81 #define BCH_IOCTL_SUBVOLUME_CREATE _IOW(0xbc,	16,  struct bch_ioctl_subvolume)
82 #define BCH_IOCTL_SUBVOLUME_DESTROY _IOW(0xbc,	17,  struct bch_ioctl_subvolume)
83 
84 /* ioctl below act on a particular file, not the filesystem as a whole: */
85 
86 #define BCHFS_IOC_REINHERIT_ATTRS	_IOR(0xbc, 64, const char __user *)
87 
88 /*
89  * BCH_IOCTL_QUERY_UUID: get filesystem UUID
90  *
91  * Returns user visible UUID, not internal UUID (which may not ever be changed);
92  * the filesystem's sysfs directory may be found under /sys/fs/bcachefs with
93  * this UUID.
94  */
95 struct bch_ioctl_query_uuid {
96 	__uuid_t		uuid;
97 };
98 
99 #if 0
100 struct bch_ioctl_start {
101 	__u32			flags;
102 	__u32			pad;
103 };
104 #endif
105 
106 /*
107  * BCH_IOCTL_DISK_ADD: add a new device to an existing filesystem
108  *
109  * The specified device must not be open or in use. On success, the new device
110  * will be an online member of the filesystem just like any other member.
111  *
112  * The device must first be prepared by userspace by formatting with a bcachefs
113  * superblock, which is only used for passing in superblock options/parameters
114  * for that device (in struct bch_member). The new device's superblock should
115  * not claim to be a member of any existing filesystem - UUIDs on it will be
116  * ignored.
117  */
118 
119 /*
120  * BCH_IOCTL_DISK_REMOVE: permanently remove a member device from a filesystem
121  *
122  * Any data present on @dev will be permanently deleted, and @dev will be
123  * removed from its slot in the filesystem's list of member devices. The device
124  * may be either offline or offline.
125  *
126  * Will fail removing @dev would leave us with insufficient read write devices
127  * or degraded/unavailable data, unless the approprate BCH_FORCE_IF_* flags are
128  * set.
129  */
130 
131 /*
132  * BCH_IOCTL_DISK_ONLINE: given a disk that is already a member of a filesystem
133  * but is not open (e.g. because we started in degraded mode), bring it online
134  *
135  * all existing data on @dev will be available once the device is online,
136  * exactly as if @dev was present when the filesystem was first mounted
137  */
138 
139 /*
140  * BCH_IOCTL_DISK_OFFLINE: offline a disk, causing the kernel to close that
141  * block device, without removing it from the filesystem (so it can be brought
142  * back online later)
143  *
144  * Data present on @dev will be unavailable while @dev is offline (unless
145  * replicated), but will still be intact and untouched if @dev is brought back
146  * online
147  *
148  * Will fail (similarly to BCH_IOCTL_DISK_SET_STATE) if offlining @dev would
149  * leave us with insufficient read write devices or degraded/unavailable data,
150  * unless the approprate BCH_FORCE_IF_* flags are set.
151  */
152 
153 struct bch_ioctl_disk {
154 	__u32			flags;
155 	__u32			pad;
156 	__u64			dev;
157 };
158 
159 /*
160  * BCH_IOCTL_DISK_SET_STATE: modify state of a member device of a filesystem
161  *
162  * @new_state		- one of the bch_member_state states (rw, ro, failed,
163  *			  spare)
164  *
165  * Will refuse to change member state if we would then have insufficient devices
166  * to write to, or if it would result in degraded data (when @new_state is
167  * failed or spare) unless the appropriate BCH_FORCE_IF_* flags are set.
168  */
169 struct bch_ioctl_disk_set_state {
170 	__u32			flags;
171 	__u8			new_state;
172 	__u8			pad[3];
173 	__u64			dev;
174 };
175 
176 enum bch_data_ops {
177 	BCH_DATA_OP_SCRUB		= 0,
178 	BCH_DATA_OP_REREPLICATE		= 1,
179 	BCH_DATA_OP_MIGRATE		= 2,
180 	BCH_DATA_OP_REWRITE_OLD_NODES	= 3,
181 	BCH_DATA_OP_NR			= 4,
182 };
183 
184 /*
185  * BCH_IOCTL_DATA: operations that walk and manipulate filesystem data (e.g.
186  * scrub, rereplicate, migrate).
187  *
188  * This ioctl kicks off a job in the background, and returns a file descriptor.
189  * Reading from the file descriptor returns a struct bch_ioctl_data_event,
190  * indicating current progress, and closing the file descriptor will stop the
191  * job. The file descriptor is O_CLOEXEC.
192  */
193 struct bch_ioctl_data {
194 	__u16			op;
195 	__u8			start_btree;
196 	__u8			end_btree;
197 	__u32			flags;
198 
199 	struct bpos		start_pos;
200 	struct bpos		end_pos;
201 
202 	union {
203 	struct {
204 		__u32		dev;
205 		__u32		pad;
206 	}			migrate;
207 	struct {
208 		__u64		pad[8];
209 	};
210 	};
211 } __packed __aligned(8);
212 
213 enum bch_data_event {
214 	BCH_DATA_EVENT_PROGRESS	= 0,
215 	/* XXX: add an event for reporting errors */
216 	BCH_DATA_EVENT_NR	= 1,
217 };
218 
219 struct bch_ioctl_data_progress {
220 	__u8			data_type;
221 	__u8			btree_id;
222 	__u8			pad[2];
223 	struct bpos		pos;
224 
225 	__u64			sectors_done;
226 	__u64			sectors_total;
227 } __packed __aligned(8);
228 
229 struct bch_ioctl_data_event {
230 	__u8			type;
231 	__u8			pad[7];
232 	union {
233 	struct bch_ioctl_data_progress p;
234 	__u64			pad2[15];
235 	};
236 } __packed __aligned(8);
237 
238 struct bch_replicas_usage {
239 	__u64			sectors;
240 	struct bch_replicas_entry r;
241 } __packed;
242 
243 static inline struct bch_replicas_usage *
244 replicas_usage_next(struct bch_replicas_usage *u)
245 {
246 	return (void *) u + replicas_entry_bytes(&u->r) + 8;
247 }
248 
249 /*
250  * BCH_IOCTL_FS_USAGE: query filesystem disk space usage
251  *
252  * Returns disk space usage broken out by data type, number of replicas, and
253  * by component device
254  *
255  * @replica_entries_bytes - size, in bytes, allocated for replica usage entries
256  *
257  * On success, @replica_entries_bytes will be changed to indicate the number of
258  * bytes actually used.
259  *
260  * Returns -ERANGE if @replica_entries_bytes was too small
261  */
262 struct bch_ioctl_fs_usage {
263 	__u64			capacity;
264 	__u64			used;
265 	__u64			online_reserved;
266 	__u64			persistent_reserved[BCH_REPLICAS_MAX];
267 
268 	__u32			replica_entries_bytes;
269 	__u32			pad;
270 
271 	struct bch_replicas_usage replicas[0];
272 };
273 
274 /*
275  * BCH_IOCTL_DEV_USAGE: query device disk space usage
276  *
277  * Returns disk space usage broken out by data type - both by buckets and
278  * sectors.
279  */
280 struct bch_ioctl_dev_usage {
281 	__u64			dev;
282 	__u32			flags;
283 	__u8			state;
284 	__u8			pad[7];
285 
286 	__u32			bucket_size;
287 	__u64			nr_buckets;
288 
289 	__u64			buckets_ec;
290 
291 	struct bch_ioctl_dev_usage_type {
292 		__u64		buckets;
293 		__u64		sectors;
294 		__u64		fragmented;
295 	}			d[BCH_DATA_NR];
296 };
297 
298 /*
299  * BCH_IOCTL_READ_SUPER: read filesystem superblock
300  *
301  * Equivalent to reading the superblock directly from the block device, except
302  * avoids racing with the kernel writing the superblock or having to figure out
303  * which block device to read
304  *
305  * @sb		- buffer to read into
306  * @size	- size of userspace allocated buffer
307  * @dev		- device to read superblock for, if BCH_READ_DEV flag is
308  *		  specified
309  *
310  * Returns -ERANGE if buffer provided is too small
311  */
312 struct bch_ioctl_read_super {
313 	__u32			flags;
314 	__u32			pad;
315 	__u64			dev;
316 	__u64			size;
317 	__u64			sb;
318 };
319 
320 /*
321  * BCH_IOCTL_DISK_GET_IDX: give a path to a block device, query filesystem to
322  * determine if disk is a (online) member - if so, returns device's index
323  *
324  * Returns -ENOENT if not found
325  */
326 struct bch_ioctl_disk_get_idx {
327 	__u64			dev;
328 };
329 
330 /*
331  * BCH_IOCTL_DISK_RESIZE: resize filesystem on a device
332  *
333  * @dev		- member to resize
334  * @nbuckets	- new number of buckets
335  */
336 struct bch_ioctl_disk_resize {
337 	__u32			flags;
338 	__u32			pad;
339 	__u64			dev;
340 	__u64			nbuckets;
341 };
342 
343 /*
344  * BCH_IOCTL_DISK_RESIZE_JOURNAL: resize journal on a device
345  *
346  * @dev		- member to resize
347  * @nbuckets	- new number of buckets
348  */
349 struct bch_ioctl_disk_resize_journal {
350 	__u32			flags;
351 	__u32			pad;
352 	__u64			dev;
353 	__u64			nbuckets;
354 };
355 
356 struct bch_ioctl_subvolume {
357 	__u32			flags;
358 	__u32			dirfd;
359 	__u16			mode;
360 	__u16			pad[3];
361 	__u64			dst_ptr;
362 	__u64			src_ptr;
363 };
364 
365 #define BCH_SUBVOL_SNAPSHOT_CREATE	(1U << 0)
366 #define BCH_SUBVOL_SNAPSHOT_RO		(1U << 1)
367 
368 #endif /* _BCACHEFS_IOCTL_H */
369