linux-stable/fs/bcachefs/bcachefs_ioctl.h
Gustavo A. R. Silva 4c26dea1c0 bcachefs: Replace zero-length array with flex-array member and use __counted_by
Fake flexible arrays (zero-length and one-element arrays) are
deprecated, and should be replaced by flexible-array members.
So, replace zero-length array with a flexible-array member in
`struct bch_ioctl_fsck_offline`.

Also annotate array `devs` with `__counted_by()` to prepare for the
coming implementation by GCC and Clang of the `__counted_by` attribute.
Flexible array members annotated with `__counted_by` can have their
accesses bounds-checked at run-time via `CONFIG_UBSAN_BOUNDS` (for
array indexing) and `CONFIG_FORTIFY_SOURCE` (for strcpy/memcpy-family
functions).

This fixes the following -Warray-bounds warnings:
fs/bcachefs/chardev.c: In function 'bch2_ioctl_fsck_offline':
fs/bcachefs/chardev.c:363:34: warning: array subscript 0 is outside array bounds of '__u64[0]' {aka 'long long unsigned int[]'} [-Warray-bounds=]
  363 |         if (copy_from_user(devs, &user_arg->devs[0], sizeof(user_arg->devs[0]) * arg.nr_devs)) {
      |                                  ^~~~~~~~~~~~~~~~~~
In file included from fs/bcachefs/chardev.c:5:
fs/bcachefs/bcachefs_ioctl.h:400:33: note: while referencing 'devs'
  400 |         __u64                   devs[0];

This results in no differences in binary output.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:41 -05:00

412 lines
10 KiB
C

/* 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_LOST \
(BCH_FORCE_IF_DATA_LOST| \
BCH_FORCE_IF_METADATA_LOST)
#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_FS_USAGE _IOWR(0xbc, 11, struct bch_ioctl_fs_usage)
#define BCH_IOCTL_DEV_USAGE _IOWR(0xbc, 11, struct bch_ioctl_dev_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, 14, struct bch_ioctl_disk_resize)
#define BCH_IOCTL_DISK_RESIZE_JOURNAL _IOW(0xbc,15, struct bch_ioctl_disk_resize_journal)
#define BCH_IOCTL_SUBVOLUME_CREATE _IOW(0xbc, 16, struct bch_ioctl_subvolume)
#define BCH_IOCTL_SUBVOLUME_DESTROY _IOW(0xbc, 17, struct bch_ioctl_subvolume)
#define BCH_IOCTL_DEV_USAGE_V2 _IOWR(0xbc, 18, struct bch_ioctl_dev_usage_v2)
#define BCH_IOCTL_FSCK_OFFLINE _IOW(0xbc, 19, struct bch_ioctl_fsck_offline)
#define BCH_IOCTL_FSCK_ONLINE _IOW(0xbc, 20, struct bch_ioctl_fsck_online)
/* ioctl below act on a particular file, not the filesystem as a whole: */
#define BCHFS_IOC_REINHERIT_ATTRS _IOR(0xbc, 64, const char __user *)
/*
* 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;
};
#define BCH_DATA_OPS() \
x(scrub, 0) \
x(rereplicate, 1) \
x(migrate, 2) \
x(rewrite_old_nodes, 3) \
x(drop_extra_replicas, 4)
enum bch_data_ops {
#define x(t, n) BCH_DATA_OP_##t = n,
BCH_DATA_OPS()
#undef x
BCH_DATA_OP_NR
};
/*
* 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 {
__u16 op;
__u8 start_btree;
__u8 end_btree;
__u32 flags;
struct bpos start_pos;
struct bpos end_pos;
union {
struct {
__u32 dev;
__u32 pad;
} migrate;
struct {
__u64 pad[8];
};
};
} __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;
} __packed __aligned(8);
struct bch_ioctl_data_event {
__u8 type;
__u8 pad[7];
union {
struct bch_ioctl_data_progress p;
__u64 pad2[15];
};
} __packed __aligned(8);
struct bch_replicas_usage {
__u64 sectors;
struct bch_replicas_entry_v1 r;
} __packed;
static inline struct bch_replicas_usage *
replicas_usage_next(struct bch_replicas_usage *u)
{
return (void *) u + replicas_entry_bytes(&u->r) + 8;
}
/*
* BCH_IOCTL_FS_USAGE: query filesystem disk space usage
*
* Returns disk space usage broken out by data type, number of replicas, and
* by component device
*
* @replica_entries_bytes - size, in bytes, allocated for replica usage entries
*
* On success, @replica_entries_bytes will be changed to indicate the number of
* bytes actually used.
*
* Returns -ERANGE if @replica_entries_bytes was too small
*/
struct bch_ioctl_fs_usage {
__u64 capacity;
__u64 used;
__u64 online_reserved;
__u64 persistent_reserved[BCH_REPLICAS_MAX];
__u32 replica_entries_bytes;
__u32 pad;
struct bch_replicas_usage replicas[];
};
/*
* BCH_IOCTL_DEV_USAGE: query device disk space usage
*
* Returns disk space usage broken out by data type - both by buckets and
* sectors.
*/
struct bch_ioctl_dev_usage {
__u64 dev;
__u32 flags;
__u8 state;
__u8 pad[7];
__u32 bucket_size;
__u64 nr_buckets;
__u64 buckets_ec;
struct bch_ioctl_dev_usage_type {
__u64 buckets;
__u64 sectors;
__u64 fragmented;
} d[10];
};
struct bch_ioctl_dev_usage_v2 {
__u64 dev;
__u32 flags;
__u8 state;
__u8 nr_data_types;
__u8 pad[6];
__u32 bucket_size;
__u64 nr_buckets;
struct bch_ioctl_dev_usage_type d[];
};
/*
* 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;
};
/*
* BCH_IOCTL_DISK_RESIZE_JOURNAL: resize journal on a device
*
* @dev - member to resize
* @nbuckets - new number of buckets
*/
struct bch_ioctl_disk_resize_journal {
__u32 flags;
__u32 pad;
__u64 dev;
__u64 nbuckets;
};
struct bch_ioctl_subvolume {
__u32 flags;
__u32 dirfd;
__u16 mode;
__u16 pad[3];
__u64 dst_ptr;
__u64 src_ptr;
};
#define BCH_SUBVOL_SNAPSHOT_CREATE (1U << 0)
#define BCH_SUBVOL_SNAPSHOT_RO (1U << 1)
/*
* BCH_IOCTL_FSCK_OFFLINE: run fsck from the 'bcachefs fsck' userspace command,
* but with the kernel's implementation of fsck:
*/
struct bch_ioctl_fsck_offline {
__u64 flags;
__u64 opts; /* string */
__u64 nr_devs;
__u64 devs[] __counted_by(nr_devs);
};
/*
* BCH_IOCTL_FSCK_ONLINE: run fsck from the 'bcachefs fsck' userspace command,
* but with the kernel's implementation of fsck:
*/
struct bch_ioctl_fsck_online {
__u64 flags;
__u64 opts; /* string */
};
#endif /* _BCACHEFS_IOCTL_H */