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-rw-r--r--c_src/cmd_super.c333
1 files changed, 333 insertions, 0 deletions
diff --git a/c_src/cmd_super.c b/c_src/cmd_super.c
new file mode 100644
index 00000000..7c0cdba0
--- /dev/null
+++ b/c_src/cmd_super.c
@@ -0,0 +1,333 @@
+/*
+ * Authors: Kent Overstreet <kent.overstreet@gmail.com>
+ * Gabriel de Perthuis <g2p.code@gmail.com>
+ * Jacob Malevich <jam@datera.io>
+ *
+ * GPLv2
+ */
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <uuid/uuid.h>
+
+#include "cmds.h"
+#include "libbcachefs.h"
+#include "libbcachefs/opts.h"
+#include "libbcachefs/super-io.h"
+#include "libbcachefs/util.h"
+
+#include "libbcachefs/darray.h"
+
+static void show_super_usage(void)
+{
+ puts("bcachefs show-super \n"
+ "Usage: bcachefs show-super [OPTION].. device\n"
+ "\n"
+ "Options:\n"
+ " -f, --fields=(fields) list of sections to print\n"
+ " --field-only=fiel) print superblock section only, no header\n"
+ " -l, --layout print superblock layout\n"
+ " -h, --help display this help and exit\n"
+ "Report bugs to <linux-bcachefs@vger.kernel.org>");
+ exit(EXIT_SUCCESS);
+}
+
+int cmd_show_super(int argc, char *argv[])
+{
+ static const struct option longopts[] = {
+ { "fields", 1, NULL, 'f' },
+ { "field-only", 1, NULL, 'F' },
+ { "layout", 0, NULL, 'l' },
+ { "help", 0, NULL, 'h' },
+ { NULL }
+ };
+ unsigned fields = 0;
+ int field_only = -1;
+ bool print_layout = false;
+ bool print_default_fields = true;
+ int opt;
+
+ while ((opt = getopt_long(argc, argv, "f:lh", longopts, NULL)) != -1)
+ switch (opt) {
+ case 'f':
+ fields = !strcmp(optarg, "all")
+ ? ~0
+ : read_flag_list_or_die(optarg,
+ bch2_sb_fields, "superblock field");
+ print_default_fields = false;
+ break;
+ case 'F':
+ field_only = read_string_list_or_die(optarg,
+ bch2_sb_fields, "superblock field");
+ print_default_fields = false;
+ break;
+ case 'l':
+ print_layout = true;
+ break;
+ case 'h':
+ show_super_usage();
+ break;
+ }
+ args_shift(optind);
+
+ char *dev = arg_pop();
+ if (!dev)
+ die("please supply a device");
+ if (argc)
+ die("too many arguments");
+
+ struct bch_opts opts = bch2_opts_empty();
+
+ opt_set(opts, noexcl, true);
+ opt_set(opts, nochanges, true);
+
+ struct bch_sb_handle sb;
+ int ret = bch2_read_super(dev, &opts, &sb);
+ if (ret)
+ die("Error opening %s: %s", dev, bch2_err_str(ret));
+
+ if (print_default_fields) {
+ fields |= bch2_sb_field_get(sb.sb, members_v2)
+ ? 1 << BCH_SB_FIELD_members_v2
+ : 1 << BCH_SB_FIELD_members_v1;
+ fields |= 1 << BCH_SB_FIELD_errors;
+ }
+
+ struct printbuf buf = PRINTBUF;
+
+ buf.human_readable_units = true;
+
+ if (field_only >= 0) {
+ struct bch_sb_field *f = bch2_sb_field_get_id(sb.sb, field_only);
+
+ if (f)
+ __bch2_sb_field_to_text(&buf, sb.sb, f);
+ } else {
+ printbuf_tabstop_push(&buf, 44);
+
+ char *model = fd_to_dev_model(sb.bdev->bd_fd);
+ prt_str(&buf, "Device:");
+ prt_tab(&buf);
+ prt_str(&buf, model);
+ prt_newline(&buf);
+ free(model);
+
+ bch2_sb_to_text(&buf, sb.sb, print_layout, fields);
+ }
+ printf("%s", buf.buf);
+
+ bch2_free_super(&sb);
+ printbuf_exit(&buf);
+ return 0;
+}
+
+#include "libbcachefs/super-io.h"
+#include "libbcachefs/sb-members.h"
+
+typedef DARRAY(struct bch_sb *) probed_sb_list;
+
+static void probe_one_super(int dev_fd, unsigned sb_size, u64 offset,
+ probed_sb_list *sbs, bool verbose)
+{
+ darray_char sb_buf = {};
+ darray_resize(&sb_buf, sb_size);
+
+ xpread(dev_fd, sb_buf.data, sb_buf.size, offset);
+
+ struct printbuf err = PRINTBUF;
+ int ret = bch2_sb_validate((void *) sb_buf.data, offset >> 9, 0, &err);
+ printbuf_exit(&err);
+
+ if (!ret) {
+ if (verbose) {
+ struct printbuf buf = PRINTBUF;
+ prt_human_readable_u64(&buf, offset);
+ printf("found superblock at %s\n", buf.buf);
+ printbuf_exit(&buf);
+ }
+
+ darray_push(sbs, (void *) sb_buf.data);
+ sb_buf.data = NULL;
+ }
+
+ darray_exit(&sb_buf);
+}
+
+static void probe_sb_range(int dev_fd, u64 start_offset, u64 end_offset,
+ probed_sb_list *sbs, bool verbose)
+{
+ start_offset &= ~((u64) 511);
+ end_offset &= ~((u64) 511);
+
+ size_t buflen = end_offset - start_offset;
+ void *buf = malloc(buflen);
+ xpread(dev_fd, buf, buflen, start_offset);
+
+ for (u64 offset = 0; offset < buflen; offset += 512) {
+ struct bch_sb *sb = buf + offset;
+
+ if (!uuid_equal(&sb->magic, &BCACHE_MAGIC) &&
+ !uuid_equal(&sb->magic, &BCHFS_MAGIC))
+ continue;
+
+ size_t bytes = vstruct_bytes(sb);
+ if (offset + bytes > buflen) {
+ fprintf(stderr, "found sb %llu size %zu that overran buffer\n",
+ start_offset + offset, bytes);
+ continue;
+ }
+ struct printbuf err = PRINTBUF;
+ int ret = bch2_sb_validate(sb, (start_offset + offset) >> 9, 0, &err);
+ if (ret)
+ fprintf(stderr, "found sb %llu that failed to validate: %s\n",
+ start_offset + offset, err.buf);
+ printbuf_exit(&err);
+
+ if (ret)
+ continue;
+
+ if (verbose) {
+ struct printbuf buf = PRINTBUF;
+ prt_human_readable_u64(&buf, start_offset + offset);
+ printf("found superblock at %s\n", buf.buf);
+ printbuf_exit(&buf);
+ }
+
+ void *sb_copy = malloc(bytes);
+ memcpy(sb_copy, sb, bytes);
+ darray_push(sbs, sb_copy);
+ }
+
+ free(buf);
+}
+
+static u64 bch2_sb_last_mount_time(struct bch_sb *sb)
+{
+ u64 ret = 0;
+ for (unsigned i = 0; i < sb->nr_devices; i++)
+ ret = max(ret, le64_to_cpu(bch2_sb_member_get(sb, i).last_mount));
+ return ret;
+}
+
+static int bch2_sb_time_cmp(struct bch_sb *l, struct bch_sb *r)
+{
+ return cmp_int(bch2_sb_last_mount_time(l),
+ bch2_sb_last_mount_time(r));
+}
+
+static void recover_super_usage(void)
+{
+ puts("bcachefs recover-super \n"
+ "Usage: bcachefs recover-super [OPTION].. device\n"
+ "\n"
+ "Attempt to recover a filesystem on a device that has had the main superblock\n"
+ "and superblock layout overwritten.\n"
+ "All options will be guessed if not provided\n"
+ "\n"
+ "Options:\n"
+ " -d, --dev_size size of filessytem on device, in bytes \n"
+ " -o, --offset offset to probe, in bytes\n"
+ " -y, --yes Recover without prompting\n"
+ " -v, --verbose Increase logging level\n"
+ " -h, --help display this help and exit\n"
+ "Report bugs to <linux-bcachefs@vger.kernel.org>");
+ exit(EXIT_SUCCESS);
+}
+
+int cmd_recover_super(int argc, char *argv[])
+{
+ static const struct option longopts[] = {
+ { "dev_size", 1, NULL, 'd' },
+ { "offset", 1, NULL, 'o' },
+ { "yes", 0, NULL, 'y' },
+ { "verbose", 0, NULL, 'v' },
+ { "help", 0, NULL, 'h' },
+ { NULL }
+ };
+ u64 dev_size = 0, offset = 0;
+ bool yes = false, verbose = false;
+ int opt;
+
+ while ((opt = getopt_long(argc, argv, "d:o:yvh", longopts, NULL)) != -1)
+ switch (opt) {
+ case 'd':
+ if (bch2_strtoull_h(optarg, &dev_size))
+ die("invalid offset");
+ break;
+ case 'o':
+ if (bch2_strtoull_h(optarg, &offset))
+ die("invalid offset");
+
+ if (offset & 511)
+ die("offset must be a multiple of 512");
+ break;
+ case 'y':
+ yes = true;
+ break;
+ case 'v':
+ verbose = true;
+ break;
+ case 'h':
+ recover_super_usage();
+ break;
+ }
+ args_shift(optind);
+
+ char *dev_path = arg_pop();
+ if (!dev_path)
+ die("please supply a device");
+ if (argc)
+ die("too many arguments");
+
+ int dev_fd = xopen(dev_path, O_RDWR);
+
+ if (!dev_size)
+ dev_size = get_size(dev_fd);
+
+ probed_sb_list sbs = {};
+
+ if (offset) {
+ probe_one_super(dev_fd, SUPERBLOCK_SIZE_DEFAULT, offset, &sbs, verbose);
+ } else {
+ unsigned scan_len = 16 << 20; /* 16MB, start and end of device */
+
+ probe_sb_range(dev_fd, 4096, scan_len, &sbs, verbose);
+ probe_sb_range(dev_fd, dev_size - scan_len, dev_size, &sbs, verbose);
+ }
+
+ if (!sbs.nr) {
+ printf("Found no bcachefs superblocks\n");
+ exit(EXIT_FAILURE);
+ }
+
+ struct bch_sb *best = NULL;
+ darray_for_each(sbs, sb)
+ if (!best || bch2_sb_time_cmp(best, *sb) < 0)
+ best = *sb;
+
+ struct printbuf buf = PRINTBUF;
+ bch2_sb_to_text(&buf, best, true, BIT_ULL(BCH_SB_FIELD_members_v2));
+
+ printf("Found superblock:\n%s", buf.buf);
+ printf("Recover?");
+
+ if (yes || ask_yn())
+ bch2_super_write(dev_fd, best);
+
+ printbuf_exit(&buf);
+ darray_for_each(sbs, sb)
+ kfree(*sb);
+ darray_exit(&sbs);
+
+ return 0;
+}
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