On Wed, Jun 22, 2016 at 07:26:46PM +0200, David Sterba wrote:
> From: David Sterba <[email protected]>
>
> Hi,
>
> the chunk dump is a useful thing, for debugging or balance filters.
>
> Example output:
>
> Chunks on device id: 1
> PNumber Type PStart Length PEnd Age
> LStart Usage
> -----------------------------------------------------------------------------------------------
> 0 System/RAID1 1.00MiB 32.00MiB 33.00MiB 47
> 1.40TiB 0.06
> 1 Metadata/RAID1 33.00MiB 1.00GiB 1.03GiB 31
> 1.36TiB 64.03
> 2 Metadata/RAID1 1.03GiB 32.00MiB 1.06GiB 36
> 1.36TiB 77.28
> 3 Data/single 1.06GiB 1.00GiB 2.06GiB 12
> 422.30GiB 78.90
> 4 Data/single 2.06GiB 1.00GiB 3.06GiB 11
> 420.30GiB 78.47
> ...
>
> (full output is at http://susepaste.org/view/raw/089a9877)
>
> This patch does the basic output, not filtering or sorting besides physical
> and
> logical offset. There are possiblities to do more or enhance the output (eg.
> starting with logical chunk and list the related physcial chunks together).
> Or filter by type/profile, or understand the balance filters format.
>
> As it is now, it's per-device dump of physical layout, which was the original
> idea.
>
> Printing 'usage' is not default as it's quite slow, it uses the search ioctl
> and probably not in the best way, or there's some other issue in the
> implementation.
>
> I'll add the patch to devel branch but will not add it for any particular
> release yet, I'd like some feedback first. Thanks.
>
> -------------
> New command 'btrfs inspect-internal dump-chunks' will dump layout of
> chunks as stored on the devices. This corresponds to the physical
> layout, sorted by the physical offset. The block group usage can be
> shown as well, but the search is too slow so it's off by default.
>
> If the physical offset sorting is selected, the empty space between
> chunks is also shown.
>
> Signed-off-by: David Sterba <[email protected]>
> ---
> cmds-inspect.c | 364
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 364 insertions(+)
>
> diff --git a/cmds-inspect.c b/cmds-inspect.c
> index dd7b9dd278f2..4eace63d8517 100644
> --- a/cmds-inspect.c
> +++ b/cmds-inspect.c
> @@ -623,6 +623,368 @@ static int cmd_inspect_min_dev_size(int argc, char
> **argv)
> return !!ret;
> }
>
> +static const char * const cmd_dump_chunks_usage[] = {
> + "btrfs inspect-internal chunk-stats [options] <path>",
> + "Show chunks (block groups) layout",
> + "Show chunks (block groups) layout for all devices",
> + "",
> + HELPINFO_UNITS_LONG,
> + "--sort=MODE sort by the physical or logical chunk start",
> + " MODE is one of pstart or lstart (default: pstart)",
> + "--usage show usage per block group, note this can be slow",
> + NULL
> +};
> +
> +enum {
> + CHUNK_SORT_PSTART,
> + CHUNK_SORT_LSTART,
> + CHUNK_SORT_DEFAULT = CHUNK_SORT_PSTART
> +};
> +
> +struct dump_chunks_entry {
> + u64 devid;
> + u64 start;
> + u64 lstart;
> + u64 length;
> + u64 flags;
> + u64 age;
> + u64 used;
> + u32 pnumber;
> +};
> +
> +struct dump_chunks_ctx {
> + unsigned length;
> + unsigned size;
> + struct dump_chunks_entry *stats;
> +};
> +
> +int cmp_cse_devid_start(const void *va, const void *vb)
> +{
> + const struct dump_chunks_entry *a = va;
> + const struct dump_chunks_entry *b = vb;
> +
> + if (a->devid < b->devid)
> + return -1;
> + if (a->devid > b->devid)
> + return 1;
> +
> + if (a->start < b->start)
> + return -1;
> + if (a->start == b->start) {
> + error(
> + "chunks start on same offset in the same device: devid %llu start %llu",
> + (unsigned long long)a->devid, (unsigned long long)a->start);
> + return 0;
> + }
> + return 1;
> +}
> +
> +int cmp_cse_devid_lstart(const void *va, const void *vb)
> +{
> + const struct dump_chunks_entry *a = va;
> + const struct dump_chunks_entry *b = vb;
> +
> + if (a->devid < b->devid)
> + return -1;
> + if (a->devid > b->devid)
> + return 1;
> +
> + if (a->lstart < b->lstart)
> + return -1;
> + if (a->lstart == b->lstart) {
> + error(
> +"chunks logically start on same offset in the same device: devid %llu start
> %llu",
> + (unsigned long long)a->devid, (unsigned long
> long)a->lstart);
> + return 0;
> + }
> + return 1;
> +}
> +
> +void print_dump_chunks(struct dump_chunks_ctx *ctx, unsigned sort_mode,
> + unsigned unit_mode, int with_usage)
> +{
> + u64 devid;
> + struct dump_chunks_entry e;
> + int i;
> + int chidx;
> + u64 lastend = 0;
> + u64 age;
> +
> + /*
> + * Chunks are sorted logically as found by the ioctl, we need to sort
> + * them once to find the physical ordering. This is the default mode.
> + */
> + qsort(ctx->stats, ctx->length, sizeof(ctx->stats[0]),
> cmp_cse_devid_start);
> + devid = 0;
> + age = 0;
> + for (i = 0; i < ctx->length; i++) {
> + e = ctx->stats[i];
> + if (e.devid != devid) {
> + devid = e.devid;
> + age = 0;
> + }
> + ctx->stats[i].pnumber = age;
> + age++;
> + }
> +
> + if (sort_mode == CHUNK_SORT_LSTART)
> + qsort(ctx->stats, ctx->length, sizeof(ctx->stats[0]),
> cmp_cse_devid_lstart);
> +
> + devid = 0;
> + for (i = 0; i < ctx->length; i++) {
> + e = ctx->stats[i];
> + if (e.devid != devid) {
> + devid = e.devid;
> + if (i != 0)
> + putchar('\n');
> + printf("Chunks on device id: %llu\n", devid);
> + printf("PNumber Type PStart
> Length PEnd Age LStart%s\n",
> + with_usage ? " Usage" : "");
> +
> printf("----------------------------------------------------------------------------------------%s\n",
> + with_usage ? "-------" : "");
> + chidx = 0;
> + lastend = 0;
> + }
> + if (sort_mode == CHUNK_SORT_PSTART && lastend > 0
> + && e.start != lastend) {
> + printf(" . empty . ");
> + printf("%12s ",
> + pretty_size_mode(e.start - lastend, unit_mode));
> + printf(" . . .\n");
> + }
> +
> + printf("%7u ", e.pnumber);
> + printf("%8s/%-6s ", btrfs_group_type_str(e.flags),
> + btrfs_group_profile_str(e.flags));
> + printf("%12s ", pretty_size_mode(e.start, unit_mode));
> + printf("%12s ", pretty_size_mode(e.length, unit_mode));
> + printf("%12s ",
> + pretty_size_mode(e.start + e.length - 1, unit_mode));
> + printf("%6llu ", e.age);
> + printf("%14s", pretty_size_mode(e.lstart, unit_mode));
> + if (with_usage)
> + printf(" %5.2f", (float)e.used / e.length * 100);
> + printf("\n");
> +
> + lastend = e.start + e.length;
> + chidx++;
> + }
> +}
> +
> +static u64 fill_usage(int fd, u64 lstart)
> +{
> + struct btrfs_ioctl_search_args args;
> + struct btrfs_ioctl_search_key *sk = &args.key;
> + struct btrfs_ioctl_search_header sh;
> + struct btrfs_block_group_item *item;
> + int ret;
> +
> + memset(&args, 0, sizeof(args));
> + sk->tree_id = BTRFS_EXTENT_TREE_OBJECTID;
> + sk->min_objectid = lstart;
> + sk->max_objectid = lstart;
> + sk->min_type = BTRFS_BLOCK_GROUP_ITEM_KEY;
> + sk->max_type = BTRFS_BLOCK_GROUP_ITEM_KEY;
> + sk->min_offset = 0;
> + sk->max_offset = (u64)-1;
> + sk->max_transid = (u64)-1;
> +
> + sk->nr_items = 4096;
What if we set nr_items = 1? From the code review, this can let us
stop and return immediately.
Thanks,
-liubo
> + ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
> + if (ret < 0) {
> + error("cannot perform the search: %s", strerror(errno));
> + return 1;
> + }
> + if (sk->nr_items == 0) {
> + warning("blockgroup %llu not found",
> + (unsigned long long)lstart);
> + return 0;
> + }
> + if (sk->nr_items > 1) {
> + warning("found more than one blockgroup %llu",
> + (unsigned long long)lstart);
> + }
> +
> + memcpy(&sh, args.buf, sizeof(sh));
> + item = (struct btrfs_block_group_item*)(args.buf + sizeof(sh));
> +
> + return item->used;
> +}
> +
> +static int cmd_dump_chunks(int argc, char **argv)
> +{
> + struct btrfs_ioctl_search_args args;
> + struct btrfs_ioctl_search_key *sk = &args.key;
> + struct btrfs_ioctl_search_header sh;
> + unsigned long off = 0;
> + u64 *age = 0;
> + unsigned age_size = 128;
> + int ret;
> + int fd;
> + int i;
> + int e;
> + DIR *dirstream = NULL;
> + unsigned unit_mode;
> + unsigned sort_mode = 0;
> + int with_usage = 0;
> + const char *path;
> + struct dump_chunks_ctx ctx = {
> + .length = 0,
> + .size = 1024,
> + .stats = NULL
> + };
> +
> + unit_mode = get_unit_mode_from_arg(&argc, argv, 0);
> +
> + while (1) {
> + int c;
> + enum { GETOPT_VAL_SORT = 256, GETOPT_VAL_USAGE };
> + static const struct option long_options[] = {
> + {"sort", required_argument, NULL, GETOPT_VAL_SORT },
> + {"usage", no_argument, NULL, GETOPT_VAL_USAGE },
> + {NULL, 0, NULL, 0}
> + };
> +
> + c = getopt_long(argc, argv, "", long_options, NULL);
> + if (c < 0)
> + break;
> +
> + switch (c) {
> + case GETOPT_VAL_SORT:
> + if (strcmp(optarg, "pstart") == 0) {
> + sort_mode = CHUNK_SORT_PSTART;
> + } else if (strcmp(optarg, "lstart") == 0) {
> + sort_mode = CHUNK_SORT_LSTART;
> + } else {
> + error("unknown sort mode: %s", optarg);
> + exit(1);
> + }
> + break;
> + case GETOPT_VAL_USAGE:
> + with_usage = 1;
> + break;
> + default:
> + usage(cmd_dump_chunks_usage);
> + }
> + }
> +
> + if (check_argc_exact(argc - optind, 1))
> + usage(cmd_dump_chunks_usage);
> +
> + ctx.stats = calloc(ctx.size, sizeof(ctx.stats[0]));
> + if (!ctx.stats)
> + goto out_nomem;
> +
> + path = argv[optind];
> +
> + fd = open_file_or_dir(path, &dirstream);
> + if (fd < 0) {
> + error("cannot access '%s': %s", path, strerror(errno));
> + return 1;
> + }
> +
> + memset(&args, 0, sizeof(args));
> + sk->tree_id = BTRFS_CHUNK_TREE_OBJECTID;
> + sk->min_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
> + sk->max_objectid = BTRFS_FIRST_CHUNK_TREE_OBJECTID;
> + sk->min_type = BTRFS_CHUNK_ITEM_KEY;
> + sk->max_type = BTRFS_CHUNK_ITEM_KEY;
> + sk->max_offset = (u64)-1;
> + sk->max_transid = (u64)-1;
> + age = calloc(age_size, sizeof(u64));
> + if (!age)
> + goto out_nomem;
> +
> + while (1) {
> + sk->nr_items = 4096;
> + ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
> + e = errno;
> + if (ret < 0) {
> + error("cannot perform the search: %s", strerror(e));
> + return 1;
> + }
> + if (sk->nr_items == 0)
> + break;
> +
> + off = 0;
> + for (i = 0; i < sk->nr_items; i++) {
> + struct btrfs_chunk *item;
> + struct btrfs_stripe *stripes;
> + int sidx;
> + u64 used = (u64)-1;
> +
> + memcpy(&sh, args.buf + off, sizeof(sh));
> + off += sizeof(sh);
> + item = (struct btrfs_chunk*)(args.buf + off);
> + off += sh.len;
> +
> + stripes = &item->stripe;
> + for (sidx = 0; sidx < item->num_stripes; sidx++) {
> + struct dump_chunks_entry *e;
> + u64 devid;
> +
> + e = &ctx.stats[ctx.length];
> + devid = stripes[sidx].devid;
> + e->devid = devid;
> + e->start = stripes[sidx].offset;
> + e->lstart = sh.offset;
> + e->length = item->length;
> + e->flags = item->type;
> + e->pnumber = -1;
> + while (devid > age_size) {
> + u64 *tmp;
> + unsigned old_size = age_size;
> +
> + age_size += 128;
> + tmp = calloc(age_size, sizeof(u64));
> + if (!tmp) {
> + free(age);
> + goto out_nomem;
> + }
> + memcpy(tmp, age, sizeof(u64) *
> old_size);
> + age = tmp;
> + }
> + e->age = age[devid]++;
> + if (with_usage) {
> + if (used == (u64)-1)
> + used = fill_usage(fd,
> sh.offset);
> + e->used = used;
> + } else {
> + e->used = 0;
> + }
> +
> + ctx.length++;
> +
> + if (ctx.length == ctx.size) {
> + ctx.size += 1024;
> + ctx.stats = realloc(ctx.stats, ctx.size
> + * sizeof(ctx.stats[0]));
> + if (!ctx.stats)
> + goto out_nomem;
> + }
> + }
> +
> + sk->min_objectid = sh.objectid;
> + sk->min_type = sh.type;
> + sk->min_offset = sh.offset;
> + }
> + if (sk->min_offset < (u64)-1)
> + sk->min_offset++;
> + else
> + break;
> + }
> +
> + print_dump_chunks(&ctx, sort_mode, unit_mode, with_usage);
> + free(ctx.stats);
> +
> + close_file_or_dir(fd, dirstream);
> + return 0;
> +
> +out_nomem:
> + error("not enough memory");
> + return 1;
> +}
> +
> static const char inspect_cmd_group_info[] =
> "query various internal information";
>
> @@ -644,6 +1006,8 @@ const struct cmd_group inspect_cmd_group = {
> cmd_inspect_dump_super_usage, NULL, 0 },
> { "tree-stats", cmd_inspect_tree_stats,
> cmd_inspect_tree_stats_usage, NULL, 0 },
> + { "dump-chunks", cmd_dump_chunks, cmd_dump_chunks_usage, NULL,
> + 0 },
> NULL_CMD_STRUCT
> }
> };
> --
> 2.7.1
>
> --
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