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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:49:52 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:49:52 +0000 |
commit | 55944e5e40b1be2afc4855d8d2baf4b73d1876b5 (patch) | |
tree | 33f869f55a1b149e9b7c2b7e201867ca5dd52992 /src/shared/loop-util.h | |
parent | Initial commit. (diff) | |
download | systemd-55944e5e40b1be2afc4855d8d2baf4b73d1876b5.tar.xz systemd-55944e5e40b1be2afc4855d8d2baf4b73d1876b5.zip |
Adding upstream version 255.4.upstream/255.4
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/shared/loop-util.h')
-rw-r--r-- | src/shared/loop-util.h | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/src/shared/loop-util.h b/src/shared/loop-util.h new file mode 100644 index 0000000..d77c314 --- /dev/null +++ b/src/shared/loop-util.h @@ -0,0 +1,59 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#include <fcntl.h> + +#include "sd-device.h" + +#include "macro.h" +#include "time-util.h" + +typedef struct LoopDevice LoopDevice; + +/* Some helpers for setting up loopback block devices */ + +struct LoopDevice { + unsigned n_ref; + int fd; + int lock_fd; + int nr; /* The loopback device index (i.e. 4 for /dev/loop4); if this object encapsulates a non-loopback block device, set to -1 */ + dev_t devno; /* The loopback device's own dev_t */ + char *node; + sd_device *dev; + char *backing_file; + bool relinquished; + dev_t backing_devno; /* The backing file's dev_t */ + ino_t backing_inode; /* The backing file's ino_t */ + uint64_t diskseq; /* Block device sequence number, monothonically incremented by the kernel on create/attach, or 0 if we don't know */ + uint64_t uevent_seqnum_not_before; /* uevent sequm right before we attached the loopback device, or UINT64_MAX if we don't know */ + usec_t timestamp_not_before; /* CLOCK_MONOTONIC timestamp taken immediately before attaching the loopback device, or USEC_INFINITY if we don't know */ + uint32_t sector_size; +}; + +/* Returns true if LoopDevice object is not actually a loopback device but some other block device we just wrap */ +#define LOOP_DEVICE_IS_FOREIGN(d) ((d)->nr < 0) + +int loop_device_make(int fd, int open_flags, uint64_t offset, uint64_t size, uint32_t sector_size, uint32_t loop_flags, int lock_op, LoopDevice **ret); +int loop_device_make_by_path_at(int dir_fd, const char *path, int open_flags, uint32_t sector_size, uint32_t loop_flags, int lock_op, LoopDevice **ret); +static inline int loop_device_make_by_path(const char *path, int open_flags, uint32_t sector_size, uint32_t loop_flags, int lock_op, LoopDevice **ret) { + return loop_device_make_by_path_at(AT_FDCWD, path, open_flags, sector_size, loop_flags, lock_op, ret); +} +int loop_device_make_by_path_memory(const char *path, int open_flags, uint32_t sector_size, uint32_t loop_flags, int lock_op, LoopDevice **ret); +int loop_device_open(sd_device *dev, int open_flags, int lock_op, LoopDevice **ret); +int loop_device_open_from_fd(int fd, int open_flags, int lock_op, LoopDevice **ret); +int loop_device_open_from_path(const char *path, int open_flags, int lock_op, LoopDevice **ret); + +LoopDevice* loop_device_ref(LoopDevice *d); +LoopDevice* loop_device_unref(LoopDevice *d); +DEFINE_TRIVIAL_CLEANUP_FUNC(LoopDevice*, loop_device_unref); + +void loop_device_relinquish(LoopDevice *d); +void loop_device_unrelinquish(LoopDevice *d); + +int loop_device_refresh_size(LoopDevice *d, uint64_t offset, uint64_t size); + +int loop_device_flock(LoopDevice *d, int operation); +int loop_device_sync(LoopDevice *d); + +int loop_device_set_autoclear(LoopDevice *d, bool autoclear); +int loop_device_set_filename(LoopDevice *d, const char *name); |