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-rw-r--r--src/sysupdate/sysupdate-partition.c284
1 files changed, 284 insertions, 0 deletions
diff --git a/src/sysupdate/sysupdate-partition.c b/src/sysupdate/sysupdate-partition.c
new file mode 100644
index 0000000..6f8e072
--- /dev/null
+++ b/src/sysupdate/sysupdate-partition.c
@@ -0,0 +1,284 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <sys/file.h>
+
+#include "alloc-util.h"
+#include "extract-word.h"
+#include "gpt.h"
+#include "id128-util.h"
+#include "parse-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "sysupdate-partition.h"
+
+void partition_info_destroy(PartitionInfo *p) {
+ assert(p);
+
+ p->label = mfree(p->label);
+ p->device = mfree(p->device);
+}
+
+int read_partition_info(
+ struct fdisk_context *c,
+ struct fdisk_table *t,
+ size_t i,
+ PartitionInfo *ret) {
+
+ _cleanup_free_ char *label_copy = NULL, *device = NULL;
+ const char *label;
+ struct fdisk_partition *p;
+ uint64_t start, size, flags;
+ unsigned long ssz;
+ sd_id128_t ptid, id;
+ GptPartitionType type;
+ size_t partno;
+ int r;
+
+ assert(c);
+ assert(t);
+ assert(ret);
+
+ p = fdisk_table_get_partition(t, i);
+ if (!p)
+ return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to read partition metadata: %m");
+
+ if (fdisk_partition_is_used(p) <= 0) {
+ *ret = (PartitionInfo) PARTITION_INFO_NULL;
+ return 0; /* not found! */
+ }
+
+ if (fdisk_partition_has_partno(p) <= 0 ||
+ fdisk_partition_has_start(p) <= 0 ||
+ fdisk_partition_has_size(p) <= 0)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Found a partition without a number, position or size.");
+
+ partno = fdisk_partition_get_partno(p);
+
+ start = fdisk_partition_get_start(p);
+ ssz = fdisk_get_sector_size(c);
+ assert(start <= UINT64_MAX / ssz);
+ start *= ssz;
+
+ size = fdisk_partition_get_size(p);
+ assert(size <= UINT64_MAX / ssz);
+ size *= ssz;
+
+ label = fdisk_partition_get_name(p);
+ if (!label)
+ return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Found a partition without a label.");
+
+ r = fdisk_partition_get_type_as_id128(p, &ptid);
+ if (r < 0)
+ return log_error_errno(r, "Failed to read partition type UUID: %m");
+
+ r = fdisk_partition_get_uuid_as_id128(p, &id);
+ if (r < 0)
+ return log_error_errno(r, "Failed to read partition UUID: %m");
+
+ r = fdisk_partition_get_attrs_as_uint64(p, &flags);
+ if (r < 0)
+ return log_error_errno(r, "Failed to get partition flags: %m");
+
+ r = fdisk_partition_to_string(p, c, FDISK_FIELD_DEVICE, &device);
+ if (r != 0)
+ return log_error_errno(r, "Failed to get partition device name: %m");
+
+ label_copy = strdup(label);
+ if (!label_copy)
+ return log_oom();
+
+ type = gpt_partition_type_from_uuid(ptid);
+
+ *ret = (PartitionInfo) {
+ .partno = partno,
+ .start = start,
+ .size = size,
+ .flags = flags,
+ .type = ptid,
+ .uuid = id,
+ .label = TAKE_PTR(label_copy),
+ .device = TAKE_PTR(device),
+ .no_auto = FLAGS_SET(flags, SD_GPT_FLAG_NO_AUTO) && gpt_partition_type_knows_no_auto(type),
+ .read_only = FLAGS_SET(flags, SD_GPT_FLAG_READ_ONLY) && gpt_partition_type_knows_read_only(type),
+ .growfs = FLAGS_SET(flags, SD_GPT_FLAG_GROWFS) && gpt_partition_type_knows_growfs(type),
+ };
+
+ return 1; /* found! */
+}
+
+int find_suitable_partition(
+ const char *device,
+ uint64_t space,
+ sd_id128_t *partition_type,
+ PartitionInfo *ret) {
+
+ _cleanup_(partition_info_destroy) PartitionInfo smallest = PARTITION_INFO_NULL;
+ _cleanup_(fdisk_unref_contextp) struct fdisk_context *c = NULL;
+ _cleanup_(fdisk_unref_tablep) struct fdisk_table *t = NULL;
+ size_t n_partitions;
+ int r;
+
+ assert(device);
+ assert(ret);
+
+ r = fdisk_new_context_at(AT_FDCWD, device, /* read_only= */ true, /* sector_size= */ UINT32_MAX, &c);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create fdisk context from '%s': %m", device);
+
+ if (!fdisk_is_labeltype(c, FDISK_DISKLABEL_GPT))
+ return log_error_errno(SYNTHETIC_ERRNO(EHWPOISON), "Disk %s has no GPT disk label, not suitable.", device);
+
+ r = fdisk_get_partitions(c, &t);
+ if (r < 0)
+ return log_error_errno(r, "Failed to acquire partition table: %m");
+
+ n_partitions = fdisk_table_get_nents(t);
+ for (size_t i = 0; i < n_partitions; i++) {
+ _cleanup_(partition_info_destroy) PartitionInfo pinfo = PARTITION_INFO_NULL;
+
+ r = read_partition_info(c, t, i, &pinfo);
+ if (r < 0)
+ return r;
+ if (r == 0) /* not assigned */
+ continue;
+
+ /* Filter out non-matching partition types */
+ if (partition_type && !sd_id128_equal(pinfo.type, *partition_type))
+ continue;
+
+ if (!streq_ptr(pinfo.label, "_empty")) /* used */
+ continue;
+
+ if (space != UINT64_MAX && pinfo.size < space) /* too small */
+ continue;
+
+ if (smallest.partno != SIZE_MAX && smallest.size <= pinfo.size) /* already found smaller */
+ continue;
+
+ smallest = pinfo;
+ pinfo = (PartitionInfo) PARTITION_INFO_NULL;
+ }
+
+ if (smallest.partno == SIZE_MAX)
+ return log_error_errno(SYNTHETIC_ERRNO(ENOSPC), "No available partition of a suitable size found.");
+
+ *ret = smallest;
+ smallest = (PartitionInfo) PARTITION_INFO_NULL;
+
+ return 0;
+}
+
+int patch_partition(
+ const char *device,
+ const PartitionInfo *info,
+ PartitionChange change) {
+
+ _cleanup_(fdisk_unref_partitionp) struct fdisk_partition *pa = NULL;
+ _cleanup_(fdisk_unref_contextp) struct fdisk_context *c = NULL;
+ bool tweak_no_auto, tweak_read_only, tweak_growfs;
+ GptPartitionType type;
+ int r, fd;
+
+ assert(device);
+ assert(info);
+ assert(change <= _PARTITION_CHANGE_MAX);
+
+ if (change == 0) /* Nothing to do */
+ return 0;
+
+ r = fdisk_new_context_at(AT_FDCWD, device, /* read_only= */ false, /* sector_size= */ UINT32_MAX, &c);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create fdisk context from '%s': %m", device);
+
+ assert_se((fd = fdisk_get_devfd(c)) >= 0);
+
+ /* Make sure udev doesn't read the device while we make changes (this lock is released automatically
+ * by the kernel when the fd is closed, i.e. when the fdisk context is freed, hence no explicit
+ * unlock by us here anywhere.) */
+ if (flock(fd, LOCK_EX) < 0)
+ return log_error_errno(errno, "Failed to lock block device '%s': %m", device);
+
+ if (!fdisk_is_labeltype(c, FDISK_DISKLABEL_GPT))
+ return log_error_errno(SYNTHETIC_ERRNO(EHWPOISON), "Disk %s has no GPT disk label, not suitable.", device);
+
+ r = fdisk_get_partition(c, info->partno, &pa);
+ if (r < 0)
+ return log_error_errno(r, "Failed to read partition %zu of GPT label of '%s': %m", info->partno, device);
+
+ if (change & PARTITION_LABEL) {
+ r = fdisk_partition_set_name(pa, info->label);
+ if (r < 0)
+ return log_error_errno(r, "Failed to update partition label: %m");
+ }
+
+ if (change & PARTITION_UUID) {
+ r = fdisk_partition_set_uuid(pa, SD_ID128_TO_UUID_STRING(info->uuid));
+ if (r < 0)
+ return log_error_errno(r, "Failed to update partition UUID: %m");
+ }
+
+ type = gpt_partition_type_from_uuid(info->type);
+
+ /* Tweak the read-only flag, but only if supported by the partition type */
+ tweak_no_auto =
+ FLAGS_SET(change, PARTITION_NO_AUTO) &&
+ gpt_partition_type_knows_no_auto(type);
+ tweak_read_only =
+ FLAGS_SET(change, PARTITION_READ_ONLY) &&
+ gpt_partition_type_knows_read_only(type);
+ tweak_growfs =
+ FLAGS_SET(change, PARTITION_GROWFS) &&
+ gpt_partition_type_knows_growfs(type);
+
+ if (change & PARTITION_FLAGS) {
+ uint64_t flags;
+
+ /* Update the full flags parameter, and import the read-only flag into it */
+
+ flags = info->flags;
+ if (tweak_no_auto)
+ SET_FLAG(flags, SD_GPT_FLAG_NO_AUTO, info->no_auto);
+ if (tweak_read_only)
+ SET_FLAG(flags, SD_GPT_FLAG_READ_ONLY, info->read_only);
+ if (tweak_growfs)
+ SET_FLAG(flags, SD_GPT_FLAG_GROWFS, info->growfs);
+
+ r = fdisk_partition_set_attrs_as_uint64(pa, flags);
+ if (r < 0)
+ return log_error_errno(r, "Failed to update partition flags: %m");
+
+ } else if (tweak_no_auto || tweak_read_only || tweak_growfs) {
+ uint64_t old_flags, new_flags;
+
+ /* So we aren't supposed to update the full flags parameter, but we are supposed to update
+ * the RO flag of it. */
+
+ r = fdisk_partition_get_attrs_as_uint64(pa, &old_flags);
+ if (r < 0)
+ return log_error_errno(r, "Failed to get old partition flags: %m");
+
+ new_flags = old_flags;
+ if (tweak_no_auto)
+ SET_FLAG(new_flags, SD_GPT_FLAG_NO_AUTO, info->no_auto);
+ if (tweak_read_only)
+ SET_FLAG(new_flags, SD_GPT_FLAG_READ_ONLY, info->read_only);
+ if (tweak_growfs)
+ SET_FLAG(new_flags, SD_GPT_FLAG_GROWFS, info->growfs);
+
+ if (new_flags != old_flags) {
+ r = fdisk_partition_set_attrs_as_uint64(pa, new_flags);
+ if (r < 0)
+ return log_error_errno(r, "Failed to update partition flags: %m");
+ }
+ }
+
+ r = fdisk_set_partition(c, info->partno, pa);
+ if (r < 0)
+ return log_error_errno(r, "Failed to update partition: %m");
+
+ r = fdisk_write_disklabel(c);
+ if (r < 0)
+ return log_error_errno(r, "Failed to write updated partition table: %m");
+
+ return 0;
+}
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