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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:35:18 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:35:18 +0000 |
commit | b750101eb236130cf056c675997decbac904cc49 (patch) | |
tree | a5df1a06754bdd014cb975c051c83b01c9a97532 /src/shared/loop-util.h | |
parent | Initial commit. (diff) | |
download | systemd-upstream.tar.xz systemd-upstream.zip |
Adding upstream version 252.22.upstream/252.22upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/shared/loop-util.h | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/src/shared/loop-util.h b/src/shared/loop-util.h new file mode 100644 index 0000000..e466a5a --- /dev/null +++ b/src/shared/loop-util.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +#pragma once + +#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; + char *node; + sd_device *dev; + char *backing_file; + bool relinquished; + 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 */ +}; + +/* 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 block_size, uint32_t loop_flags, int lock_op, LoopDevice **ret); +int loop_device_make_by_path(const char *path, int open_flags, 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); |