volume_id/fat: careful with sector#, it may not fit in 32 bits. +91 bytes
volume_id/*: a bit of code shrink
This commit is contained in:
Denis Vlasenko
parent
a34b8a4d30
commit
1e10afcdfb
@ -245,7 +245,7 @@ int volume_id_probe_vfat(struct volume_id *id, uint64_t fat_partition_off)
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buf_size = dir_entries * sizeof(struct vfat_dir_entry);
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buf = volume_id_get_buffer(id, fat_partition_off + root_start_off, buf_size);
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if (buf == NULL)
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goto found;
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goto ret;
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label = get_attr_volume_id((struct vfat_dir_entry*) buf, dir_entries);
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@ -261,7 +261,7 @@ int volume_id_probe_vfat(struct volume_id *id, uint64_t fat_partition_off)
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volume_id_set_label_string(id, vs->type.fat.label, 11);
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}
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volume_id_set_uuid(id, vs->type.fat.serno, UUID_DOS);
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goto found;
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goto ret;
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fat32:
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/* FAT32 root dir is a cluster chain like any other directory */
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@ -272,20 +272,20 @@ int volume_id_probe_vfat(struct volume_id *id, uint64_t fat_partition_off)
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next_cluster = root_cluster;
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maxloop = 100;
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while (--maxloop) {
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uint32_t next_off_sct;
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uint64_t next_off_sct;
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uint64_t next_off;
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uint64_t fat_entry_off;
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int count;
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dbg("next_cluster 0x%x", (unsigned)next_cluster);
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next_off_sct = (next_cluster - 2) * vs->sectors_per_cluster;
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next_off_sct = (uint64_t)(next_cluster - 2) * vs->sectors_per_cluster;
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next_off = (start_data_sct + next_off_sct) * sector_size_bytes;
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dbg("cluster offset 0x%llx", (unsigned long long) next_off);
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/* get cluster */
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buf = volume_id_get_buffer(id, fat_partition_off + next_off, buf_size);
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if (buf == NULL)
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goto found;
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goto ret;
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dir = (struct vfat_dir_entry*) buf;
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count = buf_size / sizeof(struct vfat_dir_entry);
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@ -300,7 +300,7 @@ int volume_id_probe_vfat(struct volume_id *id, uint64_t fat_partition_off)
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dbg("fat_entry_off 0x%llx", (unsigned long long)fat_entry_off);
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buf = volume_id_get_buffer(id, fat_partition_off + fat_entry_off, buf_size);
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if (buf == NULL)
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goto found;
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goto ret;
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/* set next cluster */
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next_cluster = le32_to_cpu(*(uint32_t*)buf) & 0x0fffffff;
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@ -323,7 +323,7 @@ int volume_id_probe_vfat(struct volume_id *id, uint64_t fat_partition_off)
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}
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volume_id_set_uuid(id, vs->type.fat32.serno, UUID_DOS);
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found:
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ret:
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// volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
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// id->type = "vfat";
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@ -195,70 +195,73 @@ set:
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* It's better to ignore such fs and continue. */
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void *volume_id_get_buffer(struct volume_id *id, uint64_t off, size_t len)
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{
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ssize_t buf_len;
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uint8_t *dst;
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unsigned small_off;
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ssize_t read_len;
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dbg("get buffer off 0x%llx(%llu), len 0x%zx",
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(unsigned long long) off, (unsigned long long) off, len);
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dbg("get buffer off 0x%llx(%llu), len 0x%zx", (unsigned long long) off, (unsigned long long) off, len);
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/* check if requested area fits in superblock buffer */
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if (off + len <= SB_BUFFER_SIZE) {
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if (off + len <= SB_BUFFER_SIZE
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/* && off <= SB_BUFFER_SIZE - want this paranoid overflow check? */
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) {
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if (id->sbbuf == NULL) {
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id->sbbuf = xmalloc(SB_BUFFER_SIZE);
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}
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small_off = off;
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dst = id->sbbuf;
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/* check if we need to read */
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if ((off + len) > id->sbbuf_len) {
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dbg("read sbbuf len:0x%llx", (unsigned long long) (off + len));
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if (lseek(id->fd, 0, SEEK_SET) != 0) {
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dbg("seek(0) failed");
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return NULL;
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}
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buf_len = full_read(id->fd, id->sbbuf, off + len);
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if (buf_len < 0) {
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dbg("read failed (%s)", strerror(errno));
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return NULL;
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}
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dbg("got 0x%zx (%zi) bytes", buf_len, buf_len);
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id->sbbuf_len = buf_len;
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if ((uint64_t)buf_len < off + len) {
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dbg("requested 0x%zx bytes, got only 0x%zx bytes", len, buf_len);
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return NULL;
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}
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}
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len += off;
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if (len <= id->sbbuf_len)
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goto ret; /* we already have it */
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return &(id->sbbuf[off]);
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dbg("read sbbuf len:0x%x", (unsigned) len);
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id->sbbuf_len = len;
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off = 0;
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goto do_read;
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}
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if (len > SEEK_BUFFER_SIZE) {
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dbg("seek buffer too small %d", SEEK_BUFFER_SIZE);
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return NULL;
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}
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/* get seek buffer */
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if (id->seekbuf == NULL) {
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id->seekbuf = xmalloc(SEEK_BUFFER_SIZE);
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}
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dst = id->seekbuf;
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/* check if we need to read */
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if ((off < id->seekbuf_off) || ((off + len) > (id->seekbuf_off + id->seekbuf_len))) {
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dbg("read seekbuf off:0x%llx len:0x%zx", (unsigned long long) off, len);
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if (lseek(id->fd, off, SEEK_SET) != off) {
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dbg("seek(0x%llx) failed", (unsigned long long) off);
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return NULL;
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}
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buf_len = full_read(id->fd, id->seekbuf, len);
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if (buf_len < 0) {
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dbg("read failed (%s)", strerror(errno));
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return NULL;
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}
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dbg("got 0x%zx (%zi) bytes", buf_len, buf_len);
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id->seekbuf_off = off;
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id->seekbuf_len = buf_len;
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if ((size_t)buf_len < len) {
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dbg("requested 0x%zx bytes, got only 0x%zx bytes", len, buf_len);
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return NULL;
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}
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if ((off >= id->seekbuf_off)
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&& ((off + len) <= (id->seekbuf_off + id->seekbuf_len))
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) {
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small_off = off - id->seekbuf_off; /* can't overflow */
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goto ret; /* we already have it */
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}
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return &(id->seekbuf[off - id->seekbuf_off]);
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id->seekbuf_off = off;
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id->seekbuf_len = len;
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id->seekbuf = xrealloc(id->seekbuf, len);
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small_off = 0;
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dst = id->seekbuf;
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dbg("read seekbuf off:0x%llx len:0x%zx",
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(unsigned long long) off, len);
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do_read:
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if (lseek(id->fd, off, SEEK_SET) != off) {
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dbg("seek(0x%llx) failed", (unsigned long long) off);
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goto err;
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}
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read_len = full_read(id->fd, dst, len);
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if (read_len != len) {
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dbg("requested 0x%x bytes, got 0x%x bytes",
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(unsigned) len, (unsigned) read_len);
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err:
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/* id->seekbuf_len or id->sbbuf_len is wrong now! Fixing.
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* Most likely user will not do any additional
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* calls anyway, it's a corrupted fs or something. */
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volume_id_free_buffer(id);
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return NULL;
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}
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ret:
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return dst + small_off;
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}
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void volume_id_free_buffer(struct volume_id *id)
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@ -269,4 +272,5 @@ void volume_id_free_buffer(struct volume_id *id)
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free(id->seekbuf);
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id->seekbuf = NULL;
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id->seekbuf_len = 0;
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id->seekbuf_off = 0; /* paranoia */
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}
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@ -61,6 +61,17 @@ struct volume_id_partition {
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#endif
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struct volume_id {
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int fd;
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// int fd_close:1;
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size_t sbbuf_len;
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size_t seekbuf_len;
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uint8_t *sbbuf;
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uint8_t *seekbuf;
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uint64_t seekbuf_off;
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#ifdef UNUSED_PARTITION_CODE
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struct volume_id_partition *partitions;
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size_t partition_count;
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#endif
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// uint8_t label_raw[VOLUME_ID_LABEL_SIZE];
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// size_t label_raw_len;
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char label[VOLUME_ID_LABEL_SIZE+1];
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@ -72,19 +83,6 @@ struct volume_id {
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// smallint usage_id;
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// const char *usage;
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// const char *type;
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#ifdef UNUSED_PARTITION_CODE
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struct volume_id_partition *partitions;
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size_t partition_count;
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#endif
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int fd;
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uint8_t *sbbuf;
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uint8_t *seekbuf;
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size_t sbbuf_len;
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uint64_t seekbuf_off;
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size_t seekbuf_len;
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// int fd_close:1;
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};
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struct volume_id *volume_id_open_node(int fd);
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