Systemd/src/basic/btrfs-util.h
Lennart Poettering 67f0ac8c79 btrfs: if BTRFS_IOC_DEV_INFO returns /dev/root generate a friendly error message
On systems that boot without initrd on a btrfs root file systems the
BTRFS_IOC_DEV_INFO ioctl returns /dev/root as backing device. That
sucks, since that is not a real device visible to userspace.

Since this has been that way since forever, and it doesn't look like the
kernel will get fixed soon for this, let's at least generate a useful
error message in this case.

This is not a bug fix, just a tweak to make this more recognizable.

Once the kernel gets fixed to report the correct device nodes in this
case, in a way userspace can make sense of them things will magically
work for systemd, too.

(Note that this doesn't add a log message about this to really all cases
we call get_device() in, but just the main ones that are called in early
boot context, after all all there's no benefit in seeing this message
too many times.)

https://github.com/systemd/systemd/issues/16953
https://bugs.freedesktop.org/show_bug.cgi?id=84689
https://bugzilla.kernel.org/show_bug.cgi?id=89721
2020-09-08 18:10:26 +02:00

130 lines
5.4 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
#pragma once
#include <stdbool.h>
#include <stdint.h>
#include <sys/types.h>
#include "sd-id128.h"
#include "copy.h"
#include "time-util.h"
typedef struct BtrfsSubvolInfo {
uint64_t subvol_id;
usec_t otime;
sd_id128_t uuid;
sd_id128_t parent_uuid;
bool read_only;
} BtrfsSubvolInfo;
typedef struct BtrfsQuotaInfo {
uint64_t referenced;
uint64_t exclusive;
uint64_t referenced_max;
uint64_t exclusive_max;
} BtrfsQuotaInfo;
typedef enum BtrfsSnapshotFlags {
BTRFS_SNAPSHOT_FALLBACK_COPY = 1 << 0, /* If the source isn't a subvolume, reflink everything */
BTRFS_SNAPSHOT_READ_ONLY = 1 << 1,
BTRFS_SNAPSHOT_RECURSIVE = 1 << 2,
BTRFS_SNAPSHOT_QUOTA = 1 << 3,
BTRFS_SNAPSHOT_FALLBACK_DIRECTORY = 1 << 4, /* If the destination doesn't support subvolumes, reflink/copy instead */
BTRFS_SNAPSHOT_FALLBACK_IMMUTABLE = 1 << 5, /* When we can't create a subvolume, use the FS_IMMUTABLE attribute for indicating read-only */
BTRFS_SNAPSHOT_SIGINT = 1 << 6, /* Check for SIGINT regularly, and return EINTR if seen */
} BtrfsSnapshotFlags;
typedef enum BtrfsRemoveFlags {
BTRFS_REMOVE_RECURSIVE = 1 << 0,
BTRFS_REMOVE_QUOTA = 1 << 1,
} BtrfsRemoveFlags;
int btrfs_is_filesystem(int fd);
int btrfs_is_subvol_fd(int fd);
int btrfs_is_subvol(const char *path);
int btrfs_reflink(int infd, int outfd);
int btrfs_clone_range(int infd, uint64_t in_offset, int ofd, uint64_t out_offset, uint64_t sz);
int btrfs_get_block_device_fd(int fd, dev_t *dev);
int btrfs_get_block_device(const char *path, dev_t *dev);
int btrfs_defrag_fd(int fd);
int btrfs_defrag(const char *p);
int btrfs_quota_enable_fd(int fd, bool b);
int btrfs_quota_enable(const char *path, bool b);
int btrfs_quota_scan_start(int fd);
int btrfs_quota_scan_wait(int fd);
int btrfs_quota_scan_ongoing(int fd);
int btrfs_subvol_make(const char *path);
int btrfs_subvol_make_fd(int fd, const char *subvolume);
int btrfs_subvol_make_fallback(const char *path, mode_t);
int btrfs_subvol_snapshot_fd_full(int old_fd, const char *new_path, BtrfsSnapshotFlags flags, copy_progress_path_t progress_path, copy_progress_bytes_t progress_bytes, void *userdata);
static inline int btrfs_subvol_snapshot_fd(int old_fd, const char *new_path, BtrfsSnapshotFlags flags) {
return btrfs_subvol_snapshot_fd_full(old_fd, new_path, flags, NULL, NULL, NULL);
}
int btrfs_subvol_snapshot_full(const char *old_path, const char *new_path, BtrfsSnapshotFlags flags, copy_progress_path_t progress_path, copy_progress_bytes_t progress_bytes, void *userdata);
static inline int btrfs_subvol_snapshot(const char *old_path, const char *new_path, BtrfsSnapshotFlags flags) {
return btrfs_subvol_snapshot_full(old_path, new_path, flags, NULL, NULL, NULL);
}
int btrfs_subvol_remove(const char *path, BtrfsRemoveFlags flags);
int btrfs_subvol_remove_fd(int fd, const char *subvolume, BtrfsRemoveFlags flags);
int btrfs_subvol_set_read_only_fd(int fd, bool b);
int btrfs_subvol_set_read_only(const char *path, bool b);
int btrfs_subvol_get_read_only_fd(int fd);
int btrfs_subvol_get_id(int fd, const char *subvolume, uint64_t *ret);
int btrfs_subvol_get_id_fd(int fd, uint64_t *ret);
int btrfs_subvol_get_parent(int fd, uint64_t subvol_id, uint64_t *ret);
int btrfs_subvol_get_info_fd(int fd, uint64_t subvol_id, BtrfsSubvolInfo *info);
int btrfs_subvol_find_subtree_qgroup(int fd, uint64_t subvol_id, uint64_t *ret);
int btrfs_subvol_get_subtree_quota(const char *path, uint64_t subvol_id, BtrfsQuotaInfo *quota);
int btrfs_subvol_get_subtree_quota_fd(int fd, uint64_t subvol_id, BtrfsQuotaInfo *quota);
int btrfs_subvol_set_subtree_quota_limit(const char *path, uint64_t subvol_id, uint64_t referenced_max);
int btrfs_subvol_set_subtree_quota_limit_fd(int fd, uint64_t subvol_id, uint64_t referenced_max);
int btrfs_subvol_auto_qgroup_fd(int fd, uint64_t subvol_id, bool new_qgroup);
int btrfs_subvol_auto_qgroup(const char *path, uint64_t subvol_id, bool create_intermediary_qgroup);
int btrfs_qgroupid_make(uint64_t level, uint64_t id, uint64_t *ret);
int btrfs_qgroupid_split(uint64_t qgroupid, uint64_t *level, uint64_t *id);
int btrfs_qgroup_create(int fd, uint64_t qgroupid);
int btrfs_qgroup_destroy(int fd, uint64_t qgroupid);
int btrfs_qgroup_destroy_recursive(int fd, uint64_t qgroupid);
int btrfs_qgroup_set_limit_fd(int fd, uint64_t qgroupid, uint64_t referenced_max);
int btrfs_qgroup_set_limit(const char *path, uint64_t qgroupid, uint64_t referenced_max);
int btrfs_qgroup_copy_limits(int fd, uint64_t old_qgroupid, uint64_t new_qgroupid);
int btrfs_qgroup_assign(int fd, uint64_t child, uint64_t parent);
int btrfs_qgroup_unassign(int fd, uint64_t child, uint64_t parent);
int btrfs_qgroup_find_parents(int fd, uint64_t qgroupid, uint64_t **ret);
int btrfs_qgroup_get_quota_fd(int fd, uint64_t qgroupid, BtrfsQuotaInfo *quota);
int btrfs_qgroup_get_quota(const char *path, uint64_t qgroupid, BtrfsQuotaInfo *quota);
static inline int btrfs_log_dev_root(int level, int ret, const char *p) {
return log_full_errno(level, ret,
"File system behind %s is reported by btrfs to be backed by pseudo-device /dev/root, which is not a valid userspace accessible device node. "
"Cannot determine correct backing block device.", p);
}