This allows to overlay bad sectors according to the mapfile generated by ddrescue, to then see where sectors are used using fsck and trying to copy files around. Signed-off-by: François Revol <revol(a)free.fr&gt; --- configure.ac | 2 + filters/ddrescue/Makefile.am | 75 +++++++ filters/ddrescue/ddrescue.c | 211 ++++++++++++++++++++ filters/ddrescue/nbdkit-ddrescue-filter.pod | 74 +++++++ 4 files changed, 362 insertions(+) create mode 100644 filters/ddrescue/Makefile.am create mode 100644 filters/ddrescue/ddrescue.c create mode 100644 filters/ddrescue/nbdkit-ddrescue-filter.pod diff --git a/configure.ac b/configure.ac index 6c25226e..21e1013f 100644 --- a/configure.ac +++ b/configure.ac @@ -97,6 +97,7 @@ filters="\ cache \ cacheextents \ cow \ + ddrescue \ delay \ error \ exitlast \ @@ -1089,6 +1090,7 @@ AC_CONFIG_FILES([Makefile filters/cache/Makefile filters/cacheextents/Makefile filters/cow/Makefile + filters/ddrescue/Makefile filters/delay/Makefile filters/error/Makefile filters/exitlast/Makefile diff --git a/filters/ddrescue/Makefile.am b/filters/ddrescue/Makefile.am new file mode 100644 index 00000000..2498074c --- /dev/null +++ b/filters/ddrescue/Makefile.am @@ -0,0 +1,75 @@ +# nbdkit +# Copyright (C) 2018 Red Hat Inc. +# +# Redistribution and use in source and binary forms, with or without +# modification, are permitted provided that the following conditions are +# met: +# +# * Redistributions of source code must retain the above copyright +# notice, this list of conditions and the following disclaimer. +# +# * Redistributions in binary form must reproduce the above copyright +# notice, this list of conditions and the following disclaimer in the +# documentation and/or other materials provided with the distribution. +# +# * Neither the name of Red Hat nor the names of its contributors may be +# used to endorse or promote products derived from this software without +# specific prior written permission. +# +# THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND +# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, +# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR +# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF +# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND +# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, +# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT +# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +# SUCH DAMAGE. + +include $(top_srcdir)/common-rules.mk + +EXTRA_DIST = \ + nbdkit-ddrescue-filter.pod \ + $(NULL) + +filter_LTLIBRARIES = nbdkit-ddrescue-filter.la + +nbdkit_ddrescue_filter_la_SOURCES = \ + ddrescue.c \ + $(top_srcdir)/include/nbdkit-filter.h \ + $(NULL) + +nbdkit_ddrescue_filter_la_CPPFLAGS = \ + -I$(top_srcdir)/include \ + -I$(top_srcdir)/common/include \ + -I$(top_srcdir)/common/sparse \ + -I$(top_srcdir)/common/utils \ + $(NULL) +nbdkit_ddrescue_filter_la_CFLAGS = \ + $(WARNINGS_CFLAGS) \ + $(GNUTLS_CFLAGS) \ + $(NULL) +nbdkit_ddrescue_filter_la_LDFLAGS = \ + -module -avoid-version -shared \ + -Wl,--version-script=$(top_srcdir)/filters/filters.syms \ + $(NULL) +nbdkit_ddrescue_filter_la_LIBADD = \ + $(top_builddir)/common/sparse/libsparse.la \ + $(top_builddir)/common/utils/libutils.la \ + $(GNUTLS_LIBS) \ + $(NULL) + +if HAVE_POD + +man_MANS = nbdkit-ddrescue-filter.1 +CLEANFILES += $(man_MANS) + +nbdkit-ddrescue-filter.1: nbdkit-ddrescue-filter.pod + $(PODWRAPPER) --section=1 --man $@ \ + --html $(top_builddir)/html/$@.html \ + $< + +endif HAVE_POD diff --git a/filters/ddrescue/ddrescue.c b/filters/ddrescue/ddrescue.c new file mode 100644 index 00000000..f6dd9382 --- /dev/null +++ b/filters/ddrescue/ddrescue.c @@ -0,0 +1,211 @@ +/* nbdkit + * Copyright (C) 2018-2020 François Revol. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * * Neither the name of Red Hat nor the names of its contributors may be + * used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, + * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A + * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF + * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <config.h> + +#include <stdio.h> +#include <stdlib.h> +#include <stdint.h> +#include <inttypes.h> +#include <string.h> + +#include <pthread.h> + +#include <nbdkit-filter.h> + +#include "cleanup.h" + +struct range { + int64_t start; + int64_t end; + int64_t size; + char status; +}; + +struct mapfile { + int ranges_count; + struct range *ranges; +}; + +static struct mapfile map = { 0, NULL }; + +static int +parse_mapfile (const char *filename) +{ + FILE *fp = NULL; + CLEANUP_FREE char *line = NULL; + size_t linelen = 0; + ssize_t len; + int ret = -1; + int status_seen = 0; + + fp = fopen (filename, "r"); + if (!fp) { + nbdkit_error ("%s: ddrescue: fopen: %m", filename); + goto out; + } + + while ((len = getline (&line, &linelen, fp)) != -1) { + const char *delim = " \t"; + char *sp, *p; + int64_t offset, length; + char status; + + if (len > 0 && line[len-1] == '\n') { + line[len-1] = '\0'; + len--; + } + + if (len > 0 && line[0] == '#') + continue; + + if (len > 0 && !status_seen) { + /* status line, ignore it for now */ + status_seen = 1; + nbdkit_debug ("%s: skipping status line: '%s'", filename, line); + continue; + } + + if (sscanf (line, "%" SCNi64 "\t%" SCNi64 "\t%c", &offset, &length, &status) == 3) { + if (offset < 0) { + nbdkit_error ("block offset must not be negative"); + return -1; + } + if (length < 0) { + nbdkit_error ("block length must not be negative"); + return -1; + } + if (status == '+') { + int i = map.ranges_count++; + map.ranges = realloc(map.ranges, map.ranges_count * sizeof(struct range)); + if (map.ranges == NULL) { + nbdkit_error ("%s: ddrescue: realloc: %m", filename); + goto out; + } + map.ranges[i].start = offset; + map.ranges[i].end = offset + length - 1; + map.ranges[i].size = length; + map.ranges[i].status = status; + } + + nbdkit_debug ("%s: range: 0x%" PRIx64 " 0x%" PRIx64 " '%c'", filename, offset, length, status); + } + } + + ret = 0; + + out: + if (fp) + fclose (fp); + return ret; +} + +/* On unload, free the sparse array. */ +static void +ddrescue_unload (void) +{ + free (map.ranges); + map.ranges = NULL; + map.ranges_count = 0; +} + +static int +ddrescue_config (nbdkit_next_config *next, void *nxdata, + const char *key, const char *value) +{ + if (strcmp (key, "ddrescue-mapfile") == 0) { + if (parse_mapfile (value) == -1) + return -1; + return 0; + } + + else + return next (nxdata, key, value); +} + +#define ddrescue_config_help \ + "ddrescue-mapfile=... Specify ddrescue mapfile to use" + +/* We need this because otherwise the layer below can_write is called + * and that might return true (eg. if the plugin has a pwrite method + * at all), resulting in writes being passed through to the layer + * below. + */ +static int +ddrescue_can_write (struct nbdkit_next_ops *next_ops, void *nxdata, + void *handle) +{ + return 0; +} + +static int +ddrescue_can_cache (struct nbdkit_next_ops *next_ops, void *nxdata, + void *handle) +{ + return 0; +} + +/* Read data. */ +static int +ddrescue_pread (struct nbdkit_next_ops *next_ops, void *nxdata, + void *handle, void *buf, uint32_t count, uint64_t offset, + uint32_t flags, int *err) +{ + int i; + + for (i = 0; i < map.ranges_count; i++) { + if (map.ranges[i].status != '+') + continue; + if (offset >= map.ranges[i].start && offset <= map.ranges[i].end) { + if (offset + count - 1 <= map.ranges[i].end) { + /* entirely contained within this range */ + return next_ops->pread (nxdata, buf, count, offset, flags, err); + } + } + } + /* read was not fully covered */ + *err = EIO; + return -1; +} + +static struct nbdkit_filter filter = { + .name = "ddrescue", + .longname = "nbdkit ddrescue mapfile filter", + .unload = ddrescue_unload, + .config = ddrescue_config, + .config_help = ddrescue_config_help, + .can_write = ddrescue_can_write, + .can_cache = ddrescue_can_cache, + .pread = ddrescue_pread, +}; + +NBDKIT_REGISTER_FILTER(filter) diff --git a/filters/ddrescue/nbdkit-ddrescue-filter.pod b/filters/ddrescue/nbdkit-ddrescue-filter.pod new file mode 100644 index 00000000..8210866b --- /dev/null +++ b/filters/ddrescue/nbdkit-ddrescue-filter.pod @@ -0,0 +1,74 @@ +=head1 NAME + +nbdkit-ddrescue-filter - nbdkit filter for serving from ddrescue dump + +=head1 SYNOPSIS + + nbdkit --filter=ddrescue plugin [plugin-args...] ddrescue-mapfile=file.map + + nbdkit --filter=ddrescue file file=file.img ddrescue-mapfile=file.map [plugin-args...] + +=head1 DESCRIPTION + +C<nbdkit-ddrescue-filter> is a filter for L<nbdkit(1)> which overlays +bad blocks according to a GNU L<ddrescue(1)> mapfile. This is mainly useful +for testing disk images recovered with ddrescue, to detect which files +or filesystem structures are impacted, or attempting fsck on them. + +Note that the current implementation is read-only. + +=head1 EXAMPLES + +=over 4 + +=item Expose a rescued disk image with detected bad sectors: + + nbdkit --filter=ddrescue file file=disk.img ddrescue-mapfile=disk.map + +The above command serves the disk image disk.img and maps the bad +sectors listed in disk.img so that read attempts on them do not return +a valid block full of zeroes. + +=back + +=head1 PARAMETERS + +The C<ddrescue-mapfile> parameter must point to a valid GNU ddrescue +mapfile. + +=head1 DATA FORMAT + +The file pointed to by the C<ddrescue-mapfile> parameter should +conform to the format of a GNU L<ddrescue(1)> mapfile. + +=head1 FILES + +=over 4 + +=item F<$filterdir/nbdkit-ddrescue-filter.so> + +The filter. + +Use C<nbdkit --dump-config> to find the location of C<$filterdir>. + +=back + +=head1 VERSION + +C<nbdkit-ddrescue-filter> first appeared in nbdkit 1.22. + +=head1 SEE ALSO + +L<nbdkit(1)>, +L<nbdkit-file-plugin(1)>, +L<nbdkit-filter(3)>, +L<ddrescue(1)>, +L<https://www.gnu.org/software/ddrescue/manual/ddrescue_manual.html>. + +=head1 AUTHORS + +François Revol + +=head1 COPYRIGHT + +Copyright (C) 2020 François Revol -- 2.26.2