diff options
Diffstat (limited to 'src/home/homework-luks.c')
| -rw-r--r-- | src/home/homework-luks.c | 69 |
1 files changed, 52 insertions, 17 deletions
diff --git a/src/home/homework-luks.c b/src/home/homework-luks.c index a2d7d388e0..2321a31021 100644 --- a/src/home/homework-luks.c +++ b/src/home/homework-luks.c @@ -38,10 +38,18 @@ #include "strv.h" #include "tmpfile-util.h" -/* Round down to the nearest 1K size. Note that Linux generally handles block devices with 512 blocks only, - * but actually doesn't accept uneven numbers in many cases. To avoid any confusion around this we'll - * strictly round disk sizes down to the next 1K boundary. */ -#define DISK_SIZE_ROUND_DOWN(x) ((x) & ~UINT64_C(1023)) +/* Round down to the nearest 4K size. Given that newer hardware generally prefers 4K sectors, let's align our + * partitions to that too. In the worst case we'll waste 3.5K per partition that way, but I think I can live + * with that. */ +#define DISK_SIZE_ROUND_DOWN(x) ((x) & ~UINT64_C(4095)) + +/* Rounds up to the nearest 4K boundary. Returns UINT64_MAX on overflow */ +#define DISK_SIZE_ROUND_UP(x) \ + ({ \ + uint64_t _x = (x); \ + _x > UINT64_MAX - 4095U ? UINT64_MAX : (_x + 4095U) & ~UINT64_C(4095); \ + }) + int run_mark_dirty(int fd, bool b) { char x = '1'; @@ -1620,7 +1628,7 @@ static int make_partition_table( _cleanup_(fdisk_unref_parttypep) struct fdisk_parttype *t = NULL; _cleanup_(fdisk_unref_contextp) struct fdisk_context *c = NULL; _cleanup_free_ char *path = NULL, *disk_uuid_as_string = NULL; - uint64_t offset, size; + uint64_t offset, size, first_lba, start, last_lba, end; sd_id128_t disk_uuid; int r; @@ -1660,17 +1668,31 @@ static int make_partition_table( if (r < 0) return log_error_errno(r, "Failed to set partition type: %m"); - r = fdisk_partition_start_follow_default(p, 1); - if (r < 0) - return log_error_errno(r, "Failed to place partition at beginning of space: %m"); - r = fdisk_partition_partno_follow_default(p, 1); if (r < 0) return log_error_errno(r, "Failed to place partition at first free partition index: %m"); - r = fdisk_partition_end_follow_default(p, 1); + first_lba = fdisk_get_first_lba(c); /* Boundary where usable space starts */ + assert(first_lba <= UINT64_MAX/512); + start = DISK_SIZE_ROUND_UP(first_lba * 512); /* Round up to multiple of 4K */ + + if (start == UINT64_MAX) + return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "Overflow while rounding up start LBA."); + + last_lba = fdisk_get_last_lba(c); /* One sector before boundary where usable space ends */ + assert(last_lba < UINT64_MAX/512); + end = DISK_SIZE_ROUND_DOWN((last_lba + 1) * 512); /* Round down to multiple of 4K */ + + if (end <= start) + return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "Resulting partition size zero or negative."); + + r = fdisk_partition_set_start(p, start / 512); if (r < 0) - return log_error_errno(r, "Failed to make partition cover all free space: %m"); + return log_error_errno(r, "Failed to place partition at offset %" PRIu64 ": %m", start); + + r = fdisk_partition_set_size(p, (end - start) / 512); + if (r < 0) + return log_error_errno(r, "Failed to end partition at offset %" PRIu64 ": %m", end); r = fdisk_partition_set_name(p, label); if (r < 0) @@ -2692,6 +2714,8 @@ int home_resize_luks( new_image_size = old_image_size; /* we can't resize physical block devices */ } else { + uint64_t new_image_size_rounded; + r = stat_verify_regular(&st); if (r < 0) return log_error_errno(r, "Image %s is not a block device nor regular file: %m", ip); @@ -2702,11 +2726,16 @@ int home_resize_luks( * apply onto the loopback file as a whole. When we operate on block devices we instead apply * to the partition itself only. */ - new_image_size = DISK_SIZE_ROUND_DOWN(h->disk_size); - if (new_image_size == old_image_size) { + new_image_size_rounded = DISK_SIZE_ROUND_DOWN(h->disk_size); + + if (old_image_size == h->disk_size || + old_image_size == new_image_size_rounded) { + /* If exact match, or a match after we rounded down, don't do a thing */ log_info("Image size already matching, skipping operation."); return 0; } + + new_image_size = new_image_size_rounded; } r = home_prepare_luks(h, already_activated, whole_disk, cache, setup, &header_home); @@ -2730,15 +2759,21 @@ int home_resize_luks( if (new_image_size <= partition_table_extra) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "New size smaller than partition table metadata."); - new_partition_size = new_image_size - partition_table_extra; + new_partition_size = DISK_SIZE_ROUND_DOWN(new_image_size - partition_table_extra); } else { + uint64_t new_partition_size_rounded; + assert(S_ISBLK(st.st_mode)); - new_partition_size = DISK_SIZE_ROUND_DOWN(h->disk_size); - if (new_partition_size == setup->partition_size) { + new_partition_size_rounded = DISK_SIZE_ROUND_DOWN(h->disk_size); + + if (h->disk_size == setup->partition_size || + new_partition_size_rounded == setup->partition_size) { log_info("Partition size already matching, skipping operation."); return 0; } + + new_partition_size = new_partition_size_rounded; } if ((UINT64_MAX - setup->partition_offset) < new_partition_size || @@ -2752,7 +2787,7 @@ int home_resize_luks( return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "New size smaller than crypto payload offset?"); old_fs_size = (setup->partition_size / 512U - crypto_offset) * 512U; - new_fs_size = (new_partition_size / 512U - crypto_offset) * 512U; + new_fs_size = DISK_SIZE_ROUND_DOWN((new_partition_size / 512U - crypto_offset) * 512U); /* Before we start doing anything, let's figure out if we actually can */ resize_type = can_resize_fs(setup->root_fd, old_fs_size, new_fs_size); |