static int _extend_buffer(struct formatter *f) { char *newbuf; log_debug_metadata("Doubling metadata output buffer to %" PRIu32, f->data.buf.size * 2); if (!(newbuf = dm_realloc(f->data.buf.start, f->data.buf.size * 2))) { log_error("Buffer reallocation failed."); return 0; } f->data.buf.start = newbuf; f->data.buf.size *= 2; return 1; }
/* * Find out vgname on a given device. */ int text_read_metadata_summary(const struct format_type *fmt, struct device *dev, dev_io_reason_t reason, off_t offset, uint32_t size, off_t offset2, uint32_t size2, checksum_fn_t checksum_fn, int checksum_only, struct lvmcache_vgsummary *vgsummary) { struct dm_config_tree *cft; struct text_vg_version_ops **vsn; int r = 0; _init_text_import(); if (!(cft = config_open(CONFIG_FILE_SPECIAL, NULL, 0))) return_0; if (dev) { log_debug_metadata("Reading metadata summary from %s at %llu size %d (+%d)", dev_name(dev), (unsigned long long)offset, size, size2); if (!config_file_read_fd(cft, dev, reason, offset, size, offset2, size2, checksum_fn, vgsummary->mda_checksum, checksum_only, 1)) { /* FIXME: handle errors */ log_error("Couldn't read volume group metadata from %s.", dev_name(dev)); goto out; } } else { if (!config_file_read(cft)) { log_error("Couldn't read volume group metadata from file."); goto out; } } if (checksum_only) { /* Checksum matches already-cached content - no need to reparse. */ log_debug_metadata("Skipped parsing metadata on %s", dev_name(dev)); r = 1; goto out; } /* * Find a set of version functions that can read this file */ for (vsn = &_text_vsn_list[0]; *vsn; vsn++) { if (!(*vsn)->check_version(cft)) continue; if (!(*vsn)->read_vgsummary(fmt, cft, vgsummary)) goto_out; r = 1; break; } out: config_destroy(cft); return r; }
struct volume_group *text_read_metadata(struct format_instance *fid, const char *file, struct cached_vg_fmtdata **vg_fmtdata, unsigned *use_previous_vg, struct device *dev, int primary_mda, off_t offset, uint32_t size, off_t offset2, uint32_t size2, checksum_fn_t checksum_fn, uint32_t checksum, time_t *when, char **desc) { struct volume_group *vg = NULL; struct dm_config_tree *cft; struct text_vg_version_ops **vsn; int skip_parse; /* * This struct holds the checksum and size of the VG metadata * that was read from a previous device. When we read the VG * metadata from this device, we can skip parsing it into a * cft (saving time) if the checksum of the metadata buffer * we read from this device matches the size/checksum saved in * the mda_header/rlocn struct on this device, and matches the * size/checksum from the previous device. */ if (vg_fmtdata && !*vg_fmtdata && !(*vg_fmtdata = dm_pool_zalloc(fid->mem, sizeof(**vg_fmtdata)))) { log_error("Failed to allocate VG fmtdata for text format."); return NULL; } _init_text_import(); *desc = NULL; *when = 0; if (!(cft = config_open(CONFIG_FILE_SPECIAL, file, 0))) return_NULL; /* Does the metadata match the already-cached VG? */ skip_parse = vg_fmtdata && ((*vg_fmtdata)->cached_mda_checksum == checksum) && ((*vg_fmtdata)->cached_mda_size == (size + size2)); if (dev) { log_debug_metadata("Reading metadata from %s at %llu size %d (+%d)", dev_name(dev), (unsigned long long)offset, size, size2); if (!config_file_read_fd(cft, dev, MDA_CONTENT_REASON(primary_mda), offset, size, offset2, size2, checksum_fn, checksum, skip_parse, 1)) { /* FIXME: handle errors */ log_error("Couldn't read volume group metadata from %s.", dev_name(dev)); goto out; } } else { if (!config_file_read(cft)) { log_error("Couldn't read volume group metadata from file."); goto out; } } if (skip_parse) { if (use_previous_vg) *use_previous_vg = 1; log_debug_metadata("Skipped parsing metadata on %s", dev_name(dev)); goto out; } /* * Find a set of version functions that can read this file */ for (vsn = &_text_vsn_list[0]; *vsn; vsn++) { if (!(*vsn)->check_version(cft)) continue; if (!(vg = (*vsn)->read_vg(fid, cft, 0))) goto_out; (*vsn)->read_desc(vg->vgmem, cft, when, desc); break; } if (vg && vg_fmtdata && *vg_fmtdata) { (*vg_fmtdata)->cached_mda_size = (size + size2); (*vg_fmtdata)->cached_mda_checksum = checksum; } if (use_previous_vg) *use_previous_vg = 0; out: config_destroy(cft); return vg; }