diff options
Diffstat (limited to 'libfdisk/src/table.c')
-rw-r--r-- | libfdisk/src/table.c | 797 |
1 files changed, 797 insertions, 0 deletions
diff --git a/libfdisk/src/table.c b/libfdisk/src/table.c new file mode 100644 index 0000000..84c60d4 --- /dev/null +++ b/libfdisk/src/table.c @@ -0,0 +1,797 @@ + +#include "fdiskP.h" + +/** + * SECTION: table + * @title: Table + * @short_description: container for fdisk partitions + * + * The fdisk_table is simple container for fdisk_partitions. The table is no + * directly connected to label data (partition table), and table changes don't + * affect in-memory or on-disk data. + */ + +/** + * fdisk_new_table: + * + * The table is a container for struct fdisk_partition entries. The container + * does not have any real connection with label (partition table) and with + * real on-disk data. + * + * Returns: newly allocated table struct. + */ +struct fdisk_table *fdisk_new_table(void) +{ + struct fdisk_table *tb = NULL; + + tb = calloc(1, sizeof(*tb)); + if (!tb) + return NULL; + + DBG(TAB, ul_debugobj(tb, "alloc")); + tb->refcount = 1; + INIT_LIST_HEAD(&tb->parts); + return tb; +} + +/** + * fdisk_reset_table: + * @tb: tab pointer + * + * Removes all entries (partitions) from the table. The partitions with zero + * reference count will be deallocated. This function does not modify partition + * table. + * + * Returns: 0 on success or negative number in case of error. + */ +int fdisk_reset_table(struct fdisk_table *tb) +{ + if (!tb) + return -EINVAL; + + DBG(TAB, ul_debugobj(tb, "reset")); + + while (!list_empty(&tb->parts)) { + struct fdisk_partition *pa = list_entry(tb->parts.next, + struct fdisk_partition, parts); + fdisk_table_remove_partition(tb, pa); + } + + tb->nents = 0; + return 0; +} + +/** + * fdisk_ref_table: + * @tb: table pointer + * + * Increments reference counter. + */ +void fdisk_ref_table(struct fdisk_table *tb) +{ + if (tb) + tb->refcount++; +} + +/** + * fdisk_unref_table: + * @tb: table pointer + * + * Descrements reference counter, on zero the @tb is automatically + * deallocated. + */ +void fdisk_unref_table(struct fdisk_table *tb) +{ + if (!tb) + return; + + tb->refcount--; + if (tb->refcount <= 0) { + fdisk_reset_table(tb); + + DBG(TAB, ul_debugobj(tb, "free")); + free(tb); + } +} + +/** + * fdisk_table_is_empty: + * @tb: pointer to tab + * + * Returns: 1 if the table is without filesystems, or 0. + */ +int fdisk_table_is_empty(struct fdisk_table *tb) +{ + return tb == NULL || list_empty(&tb->parts) ? 1 : 0; +} + +/** + * fdisk_table_get_nents: + * @tb: pointer to tab + * + * Returns: number of entries in table. + */ +size_t fdisk_table_get_nents(struct fdisk_table *tb) +{ + return tb ? tb->nents : 0; +} + +/** + * fdisk_table_next_partition: + * @tb: tab pointer + * @itr: iterator + * @pa: returns the next tab entry + * + * Returns: 0 on success, negative number in case of error or 1 at the end of list. + * + * Example: + * <informalexample> + * <programlisting> + * while(fdisk_table_next_partition(tb, itr, &pa) == 0) { + * ... + * } + * </programlisting> + * </informalexample> + */ +int fdisk_table_next_partition( + struct fdisk_table *tb, + struct fdisk_iter *itr, + struct fdisk_partition **pa) +{ + int rc = 1; + + if (!tb || !itr || !pa) + return -EINVAL; + *pa = NULL; + + if (!itr->head) + FDISK_ITER_INIT(itr, &tb->parts); + if (itr->p != itr->head) { + FDISK_ITER_ITERATE(itr, *pa, struct fdisk_partition, parts); + rc = 0; + } + + return rc; +} + +/** + * fdisk_table_get_partition: + * @tb: tab pointer + * @n: number of entry in table + * + * Returns: n-th entry from table or NULL + */ +struct fdisk_partition *fdisk_table_get_partition( + struct fdisk_table *tb, + size_t n) +{ + struct fdisk_partition *pa = NULL; + struct fdisk_iter itr; + + if (!tb) + return NULL; + + fdisk_reset_iter(&itr, FDISK_ITER_FORWARD); + + while (fdisk_table_next_partition(tb, &itr, &pa) == 0) { + if (n == 0) + return pa; + n--; + } + + return NULL; +} + +/** + * fdisk_table_get_partition_by_partno: + * @tb: tab pointer + * @partno: partition number + * + * Returns: partition with @partno or NULL. + */ +struct fdisk_partition *fdisk_table_get_partition_by_partno( + struct fdisk_table *tb, + size_t partno) +{ + struct fdisk_partition *pa = NULL; + struct fdisk_iter itr; + + if (!tb) + return NULL; + + fdisk_reset_iter(&itr, FDISK_ITER_FORWARD); + + while (fdisk_table_next_partition(tb, &itr, &pa) == 0) { + if (pa->partno == partno) + return pa; + } + + return NULL; +} + +/** + * fdisk_table_add_partition + * @tb: tab pointer + * @pa: new entry + * + * Adds a new entry to table and increment @pa reference counter. Don't forget to + * use fdisk_unref_partition() after fdisk_table_add_partition() if you want to keep + * the @pa referenced by the table only. + * + * Returns: 0 on success or negative number in case of error. + */ +int fdisk_table_add_partition(struct fdisk_table *tb, struct fdisk_partition *pa) +{ + if (!tb || !pa) + return -EINVAL; + + if (!list_empty(&pa->parts)) + return -EBUSY; + + fdisk_ref_partition(pa); + list_add_tail(&pa->parts, &tb->parts); + tb->nents++; + + DBG(TAB, ul_debugobj(tb, "add entry %p [start=%ju, end=%ju, size=%ju, %s %s %s]", + pa, + (uintmax_t) fdisk_partition_get_start(pa), + fdisk_partition_has_end(pa) ? (uintmax_t) fdisk_partition_get_end(pa) : 0, + fdisk_partition_has_size(pa) ? (uintmax_t) fdisk_partition_get_size(pa) : 0, + fdisk_partition_is_freespace(pa) ? "freespace" : "", + fdisk_partition_is_nested(pa) ? "nested" : "", + fdisk_partition_is_container(pa) ? "container" : "primary")); + return 0; +} + +/* inserts @pa after @poz */ +static int table_insert_partition( + struct fdisk_table *tb, + struct fdisk_partition *poz, + struct fdisk_partition *pa) +{ + assert(tb); + assert(pa); + + fdisk_ref_partition(pa); + if (poz) + list_add(&pa->parts, &poz->parts); + else + list_add(&pa->parts, &tb->parts); + tb->nents++; + + DBG(TAB, ul_debugobj(tb, "insert entry %p pre=%p [start=%ju, end=%ju, size=%ju, %s %s %s]", + pa, poz ? poz : NULL, + (uintmax_t) fdisk_partition_get_start(pa), + (uintmax_t) fdisk_partition_get_end(pa), + (uintmax_t) fdisk_partition_get_size(pa), + fdisk_partition_is_freespace(pa) ? "freespace" : "", + fdisk_partition_is_nested(pa) ? "nested" : "", + fdisk_partition_is_container(pa) ? "container" : "")); + return 0; +} + +/** + * fdisk_table_remove_partition + * @tb: tab pointer + * @pa: new entry + * + * Removes the @pa from the table and de-increment reference counter of the @pa. The + * partition with zero reference counter will be deallocated. Don't forget to use + * fdisk_ref_partition() before call fdisk_table_remove_partition() if you want + * to use @pa later. + * + * Returns: 0 on success or negative number in case of error. + */ +int fdisk_table_remove_partition(struct fdisk_table *tb, struct fdisk_partition *pa) +{ + if (!tb || !pa) + return -EINVAL; + + DBG(TAB, ul_debugobj(tb, "remove entry %p", pa)); + list_del(&pa->parts); + INIT_LIST_HEAD(&pa->parts); + + fdisk_unref_partition(pa); + tb->nents--; + + return 0; +} + +/** + * fdisk_get_partitions + * @cxt: fdisk context + * @tb: returns table + * + * This function adds partitions from disklabel to @table, it allocates a new + * table if @table points to NULL. + * + * Returns: 0 on success, otherwise, a corresponding error. + */ +int fdisk_get_partitions(struct fdisk_context *cxt, struct fdisk_table **tb) +{ + size_t i; + + if (!cxt || !cxt->label || !tb) + return -EINVAL; + if (!cxt->label->op->get_part) + return -ENOSYS; + + DBG(CXT, ul_debugobj(cxt, " -- get table --")); + + if (!*tb && !(*tb = fdisk_new_table())) + return -ENOMEM; + + for (i = 0; i < cxt->label->nparts_max; i++) { + struct fdisk_partition *pa = NULL; + + if (fdisk_get_partition(cxt, i, &pa) != 0) + continue; + if (fdisk_partition_is_used(pa)) + fdisk_table_add_partition(*tb, pa); + fdisk_unref_partition(pa); + } + + return 0; +} + +void fdisk_debug_print_table(struct fdisk_table *tb) +{ + struct fdisk_iter itr; + struct fdisk_partition *pa; + + fdisk_reset_iter(&itr, FDISK_ITER_FORWARD); + while (fdisk_table_next_partition(tb, &itr, &pa) == 0) + ul_debugobj(tb, "partition %p [partno=%zu, start=%ju, end=%ju, size=%ju%s%s%s] ", + pa, pa->partno, + (uintmax_t) fdisk_partition_get_start(pa), + (uintmax_t) fdisk_partition_get_end(pa), + (uintmax_t) fdisk_partition_get_size(pa), + fdisk_partition_is_nested(pa) ? " nested" : "", + fdisk_partition_is_freespace(pa) ? " freespace" : "", + fdisk_partition_is_container(pa) ? " container" : ""); + +} + + +typedef int (*fdisk_partcmp_t)(struct fdisk_partition *, struct fdisk_partition *); + +static int cmp_parts_wrapper(struct list_head *a, struct list_head *b, void *data) +{ + struct fdisk_partition *pa = list_entry(a, struct fdisk_partition, parts), + *pb = list_entry(b, struct fdisk_partition, parts); + + fdisk_partcmp_t cmp = (fdisk_partcmp_t) data; + + return cmp(pa, pb); +} + + +/** + * fdisk_table_sort_partitions: + * @tb: table + * @cmp: compare function + * + * Sort partition in the table. + * + * Returns: 0 on success, <0 on error. + */ +int fdisk_table_sort_partitions(struct fdisk_table *tb, + int (*cmp)(struct fdisk_partition *, + struct fdisk_partition *)) +{ + if (!tb) + return -EINVAL; + + /* + DBG(TAB, ul_debugobj(tb, "Before sort:")); + ON_DBG(TAB, fdisk_debug_print_table(tb)); + */ + + list_sort(&tb->parts, cmp_parts_wrapper, (void *) cmp); + + /* + DBG(TAB, ul_debugobj(tb, "After sort:")); + ON_DBG(TAB, fdisk_debug_print_table(tb)); + */ + + return 0; +} + +/* allocates a new freespace description */ +static int new_freespace(struct fdisk_context *cxt, + fdisk_sector_t start, + fdisk_sector_t end, + struct fdisk_partition *parent, + struct fdisk_partition **pa) +{ + fdisk_sector_t aligned_start, size; + + assert(cxt); + assert(pa); + + *pa = NULL; + + if (start == end) + return 0; + + assert(start >= cxt->first_lba); + assert(end); + assert(end > start); + + aligned_start = fdisk_align_lba_in_range(cxt, start, start, end); + size = end - aligned_start + 1ULL; + + if (size == 0) { + DBG(TAB, ul_debug("ignore freespace (aligned size is zero)")); + return 0; + } + + *pa = fdisk_new_partition(); + if (!*pa) + return -ENOMEM; + + (*pa)->freespace = 1; + (*pa)->start = aligned_start; + (*pa)->size = size; + + if (parent) + (*pa)->parent_partno = parent->partno; + return 0; +} + +/* add freespace description to the right place within @tb */ +static int table_add_freespace( + struct fdisk_context *cxt, + struct fdisk_table *tb, + fdisk_sector_t start, + fdisk_sector_t end, + struct fdisk_partition *parent) +{ + struct fdisk_partition *pa, *x, *real_parent = NULL, *best = NULL; + struct fdisk_iter itr; + int rc = 0; + + assert(tb); + + rc = new_freespace(cxt, start, end, parent, &pa); + if (rc) + return -ENOMEM; + if (!pa) + return 0; + + assert(fdisk_partition_has_start(pa)); + assert(fdisk_partition_has_end(pa)); + + DBG(TAB, ul_debugobj(tb, "adding freespace")); + + fdisk_reset_iter(&itr, FDISK_ITER_FORWARD); + if (parent && fdisk_partition_has_partno(parent)) { + while (fdisk_table_next_partition(tb, &itr, &x) == 0) { + if (!fdisk_partition_has_partno(x)) + continue; + if (x->partno == parent->partno) { + real_parent = x; + break; + } + } + if (!real_parent) { + DBG(TAB, ul_debugobj(tb, "not found freespace parent (partno=%zu)", + parent->partno)); + fdisk_reset_iter(&itr, FDISK_ITER_FORWARD); + } + } + + while (fdisk_table_next_partition(tb, &itr, &x) == 0) { + fdisk_sector_t the_end, best_end = 0; + + if (!fdisk_partition_has_end(x)) + continue; + + the_end = fdisk_partition_get_end(x); + if (best) + best_end = fdisk_partition_get_end(best); + + if (the_end < pa->start && (!best || best_end < the_end)) + best = x; + } + + if (!best && real_parent) + best = real_parent; + rc = table_insert_partition(tb, best, pa); + + fdisk_unref_partition(pa); + + DBG(TAB, ul_debugobj(tb, "adding freespace DONE [rc=%d]", rc)); + return rc; +} + +/* analyze @cont(ainer) in @parts and add all detected freespace into @tb, note + * that @parts has to be sorted by partition starts */ +static int check_container_freespace(struct fdisk_context *cxt, + struct fdisk_table *parts, + struct fdisk_table *tb, + struct fdisk_partition *cont) +{ + struct fdisk_iter itr; + struct fdisk_partition *pa; + fdisk_sector_t x, last, grain, lastplusoff; + int rc = 0; + + assert(cxt); + assert(parts); + assert(tb); + assert(cont); + assert(fdisk_partition_has_start(cont)); + + DBG(TAB, ul_debugobj(tb, "analyze container 0x%p", cont)); + + last = fdisk_partition_get_start(cont); + grain = cxt->grain > cxt->sector_size ? cxt->grain / cxt->sector_size : 1; + fdisk_reset_iter(&itr, FDISK_ITER_FORWARD); + + DBG(CXT, ul_debugobj(cxt, "initialized: last=%ju, grain=%ju", + (uintmax_t)last, (uintmax_t)grain)); + + while (fdisk_table_next_partition(parts, &itr, &pa) == 0) { + + DBG(CXT, ul_debugobj(cxt, "partno=%zu, start=%ju", + pa->partno, (uintmax_t)pa->start)); + + if (!pa->used || !fdisk_partition_is_nested(pa) + || !fdisk_partition_has_start(pa)) + continue; + + DBG(CXT, ul_debugobj(cxt, "freespace container analyze: partno=%zu, start=%ju, end=%ju", + pa->partno, + (uintmax_t) fdisk_partition_get_start(pa), + (uintmax_t) fdisk_partition_get_end(pa))); + + lastplusoff = last + cxt->first_lba; + if (pa->start > lastplusoff && pa->start - lastplusoff > grain) + rc = table_add_freespace(cxt, tb, lastplusoff, pa->start, cont); + if (rc) + goto done; + last = fdisk_partition_get_end(pa); + } + + /* free-space remaining in extended partition */ + x = fdisk_partition_get_start(cont) + fdisk_partition_get_size(cont) - 1; + lastplusoff = last + cxt->first_lba; + if (lastplusoff < x && x - lastplusoff > grain) { + DBG(TAB, ul_debugobj(tb, "add remaining space in container 0x%p", cont)); + rc = table_add_freespace(cxt, tb, lastplusoff, x, cont); + } + +done: + DBG(TAB, ul_debugobj(tb, "analyze container 0x%p DONE [rc=%d]", cont, rc)); + return rc; +} + + +/** + * fdisk_get_freespaces + * @cxt: fdisk context + * @tb: returns table + * + * This function adds freespace (described by fdisk_partition) to @table, it + * allocates a new table if the @table points to NULL. + * + * Note that free space smaller than grain (see fdisk_get_grain_size()) is + * ignored. + * + * Returns: 0 on success, otherwise, a corresponding error. + */ +int fdisk_get_freespaces(struct fdisk_context *cxt, struct fdisk_table **tb) +{ + int rc = 0; + size_t nparts = 0; + fdisk_sector_t last, grain; + struct fdisk_table *parts = NULL; + struct fdisk_partition *pa; + struct fdisk_iter itr; + + DBG(CXT, ul_debugobj(cxt, "-- get freespace --")); + + if (!cxt || !cxt->label || !tb) + return -EINVAL; + if (!*tb && !(*tb = fdisk_new_table())) + return -ENOMEM; + + rc = fdisk_get_partitions(cxt, &parts); + if (rc) + goto done; + + fdisk_table_sort_partitions(parts, fdisk_partition_cmp_start); + fdisk_reset_iter(&itr, FDISK_ITER_FORWARD); + last = cxt->first_lba; + grain = cxt->grain > cxt->sector_size ? cxt->grain / cxt->sector_size : 1; + + DBG(CXT, ul_debugobj(cxt, "initialized: last=%ju, grain=%ju", + (uintmax_t)last, (uintmax_t)grain)); + + /* analyze gaps between partitions */ + while (rc == 0 && fdisk_table_next_partition(parts, &itr, &pa) == 0) { + + DBG(CXT, ul_debugobj(cxt, "partno=%zu, start=%ju", + pa->partno, (uintmax_t)pa->start)); + + if (!pa->used || pa->wholedisk || fdisk_partition_is_nested(pa) + || !fdisk_partition_has_start(pa)) + continue; + DBG(CXT, ul_debugobj(cxt, "freespace analyze: partno=%zu, start=%ju, end=%ju", + pa->partno, + (uintmax_t) fdisk_partition_get_start(pa), + (uintmax_t) fdisk_partition_get_end(pa))); + + /* We ignore small free spaces (smaller than grain) to keep partitions + * aligned, the exception is space before the first partition when + * cxt->first_lba is aligned. */ + if (last + grain < pa->start + || (nparts == 0 && + (fdisk_align_lba(cxt, last, FDISK_ALIGN_UP) < + pa->start))) { + rc = table_add_freespace(cxt, *tb, + last + (nparts == 0 ? 0 : 1), + pa->start - 1, NULL); + } + /* add gaps between logical partitions */ + if (fdisk_partition_is_container(pa)) + rc = check_container_freespace(cxt, parts, *tb, pa); + + if (fdisk_partition_has_end(pa)) { + fdisk_sector_t pa_end = fdisk_partition_get_end(pa); + if (pa_end > last) + last = fdisk_partition_get_end(pa); + } + nparts++; + } + + /* add free-space behind last partition to the end of the table (so + * don't use table_add_freespace()) */ + if (rc == 0 && last + grain < cxt->last_lba - 1) { + DBG(CXT, ul_debugobj(cxt, "freespace behind last partition detected")); + rc = new_freespace(cxt, + last + (last > cxt->first_lba || nparts ? 1 : 0), + cxt->last_lba, NULL, &pa); + if (pa) { + fdisk_table_add_partition(*tb, pa); + fdisk_unref_partition(pa); + } + } + +done: + fdisk_unref_table(parts); + + DBG(CXT, ul_debugobj(cxt, "get freespace DONE [rc=%d]", rc)); + return rc; +} + +/** + * fdisk_table_wrong_order: + * @tb: table + * + * Returns: 1 of the table is not in disk order + */ +int fdisk_table_wrong_order(struct fdisk_table *tb) +{ + struct fdisk_partition *pa; + struct fdisk_iter itr; + fdisk_sector_t last = 0; + + DBG(TAB, ul_debugobj(tb, "wrong older check")); + + fdisk_reset_iter(&itr, FDISK_ITER_FORWARD); + while (tb && fdisk_table_next_partition(tb, &itr, &pa) == 0) { + if (!fdisk_partition_has_start(pa) || fdisk_partition_is_wholedisk(pa)) + continue; + if (pa->start < last) + return 1; + last = pa->start; + } + return 0; +} + +/** + * fdisk_apply_table: + * @cxt: context + * @tb: table + * + * Add partitions from table @tb to the in-memory disk label. See + * fdisk_add_partition(), fdisk_delete_all_partitions(). The partitions + * that does not define start (or does not follow the default start) + * are ignored. + * + * Returns: 0 on success, <0 on error. + */ +int fdisk_apply_table(struct fdisk_context *cxt, struct fdisk_table *tb) +{ + struct fdisk_partition *pa; + struct fdisk_iter itr; + int rc = 0; + + assert(cxt); + assert(tb); + + DBG(TAB, ul_debugobj(tb, "applying to context %p", cxt)); + + fdisk_reset_iter(&itr, FDISK_ITER_FORWARD); + while (tb && fdisk_table_next_partition(tb, &itr, &pa) == 0) { + if (!fdisk_partition_has_start(pa) && !pa->start_follow_default) + continue; + rc = fdisk_add_partition(cxt, pa, NULL); + if (rc) + break; + } + + return rc; +} + +int fdisk_diff_tables(struct fdisk_table *a, struct fdisk_table *b, + struct fdisk_iter *itr, + struct fdisk_partition **res, int *change) +{ + struct fdisk_partition *pa = NULL, *pb; + int rc = 1; + + assert(itr); + assert(res); + assert(change); + + DBG(TAB, ul_debugobj(a, "table diff [new table=%p]", b)); + + if (a && (itr->head == NULL || itr->head == &a->parts)) { + DBG(TAB, ul_debugobj(a, " scanning old table")); + do { + rc = fdisk_table_next_partition(a, itr, &pa); + if (rc != 0) + break; + } while (!fdisk_partition_has_partno(pa)); + } + + if (rc == 1 && b) { + DBG(TAB, ul_debugobj(a, " scanning new table")); + if (itr->head != &b->parts) { + DBG(TAB, ul_debugobj(a, " initialize to TAB=%p", b)); + fdisk_reset_iter(itr, FDISK_ITER_FORWARD); + } + + while (fdisk_table_next_partition(b, itr, &pb) == 0) { + if (!fdisk_partition_has_partno(pb)) + continue; + if (a == NULL || + fdisk_table_get_partition_by_partno(a, pb->partno) == NULL) { + DBG(TAB, ul_debugobj(a, " #%zu ADDED", pb->partno)); + *change = FDISK_DIFF_ADDED; + *res = pb; + return 0; + } + } + } + + if (rc) { + DBG(TAB, ul_debugobj(a, "table diff done [rc=%d]", rc)); + return rc; /* error or done */ + } + + pb = fdisk_table_get_partition_by_partno(b, pa->partno); + + if (!pb) { + DBG(TAB, ul_debugobj(a, " #%zu REMOVED", pa->partno)); + *change = FDISK_DIFF_REMOVED; + *res = pa; + } else if (pb->start != pa->start) { + DBG(TAB, ul_debugobj(a, " #%zu MOVED", pb->partno)); + *change = FDISK_DIFF_MOVED; + *res = pb; + } else if (pb->size != pa->size) { + DBG(TAB, ul_debugobj(a, " #%zu RESIZED", pb->partno)); + *change = FDISK_DIFF_RESIZED; + *res = pb; + } else { + DBG(TAB, ul_debugobj(a, " #%zu UNCHANGED", pb->partno)); + *change = FDISK_DIFF_UNCHANGED; + *res = pa; + } + return 0; +} + |