--- /dev/null
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Fabian Ebner <f.ebner@proxmox.com>
+Date: Thu, 21 Apr 2022 13:26:48 +0200
+Subject: [PATCH] vma: allow partial restore
+
+Introduce a new map line for skipping a certain drive, of the form
+skip=drive-scsi0
+
+Since in PVE, most archives are compressed and piped to vma for
+restore, it's not easily possible to skip reads.
+
+For the reader, a new skip flag for VmaRestoreState is added and the
+target is allowed to be NULL if skip is specified when registering. If
+the skip flag is set, no writes will be made as well as no check for
+duplicate clusters. Therefore, the flag is not set for verify.
+
+Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>
+Acked-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
+Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
+---
+ vma-reader.c | 64 ++++++++++++---------
+ vma.c | 157 +++++++++++++++++++++++++++++----------------------
+ vma.h | 2 +-
+ 3 files changed, 126 insertions(+), 97 deletions(-)
+
+diff --git a/vma-reader.c b/vma-reader.c
+index e65f1e8415..81a891c6b1 100644
+--- a/vma-reader.c
++++ b/vma-reader.c
+@@ -28,6 +28,7 @@ typedef struct VmaRestoreState {
+ bool write_zeroes;
+ unsigned long *bitmap;
+ int bitmap_size;
++ bool skip;
+ } VmaRestoreState;
+
+ struct VmaReader {
+@@ -425,13 +426,14 @@ VmaDeviceInfo *vma_reader_get_device_info(VmaReader *vmar, guint8 dev_id)
+ }
+
+ static void allocate_rstate(VmaReader *vmar, guint8 dev_id,
+- BlockBackend *target, bool write_zeroes)
++ BlockBackend *target, bool write_zeroes, bool skip)
+ {
+ assert(vmar);
+ assert(dev_id);
+
+ vmar->rstate[dev_id].target = target;
+ vmar->rstate[dev_id].write_zeroes = write_zeroes;
++ vmar->rstate[dev_id].skip = skip;
+
+ int64_t size = vmar->devinfo[dev_id].size;
+
+@@ -446,28 +448,30 @@ static void allocate_rstate(VmaReader *vmar, guint8 dev_id,
+ }
+
+ int vma_reader_register_bs(VmaReader *vmar, guint8 dev_id, BlockBackend *target,
+- bool write_zeroes, Error **errp)
++ bool write_zeroes, bool skip, Error **errp)
+ {
+ assert(vmar);
+- assert(target != NULL);
++ assert(target != NULL || skip);
+ assert(dev_id);
+- assert(vmar->rstate[dev_id].target == NULL);
+-
+- int64_t size = blk_getlength(target);
+- int64_t size_diff = size - vmar->devinfo[dev_id].size;
+-
+- /* storage types can have different size restrictions, so it
+- * is not always possible to create an image with exact size.
+- * So we tolerate a size difference up to 4MB.
+- */
+- if ((size_diff < 0) || (size_diff > 4*1024*1024)) {
+- error_setg(errp, "vma_reader_register_bs for stream %s failed - "
+- "unexpected size %zd != %zd", vmar->devinfo[dev_id].devname,
+- size, vmar->devinfo[dev_id].size);
+- return -1;
++ assert(vmar->rstate[dev_id].target == NULL && !vmar->rstate[dev_id].skip);
++
++ if (target != NULL) {
++ int64_t size = blk_getlength(target);
++ int64_t size_diff = size - vmar->devinfo[dev_id].size;
++
++ /* storage types can have different size restrictions, so it
++ * is not always possible to create an image with exact size.
++ * So we tolerate a size difference up to 4MB.
++ */
++ if ((size_diff < 0) || (size_diff > 4*1024*1024)) {
++ error_setg(errp, "vma_reader_register_bs for stream %s failed - "
++ "unexpected size %zd != %zd", vmar->devinfo[dev_id].devname,
++ size, vmar->devinfo[dev_id].size);
++ return -1;
++ }
+ }
+
+- allocate_rstate(vmar, dev_id, target, write_zeroes);
++ allocate_rstate(vmar, dev_id, target, write_zeroes, skip);
+
+ return 0;
+ }
+@@ -560,19 +564,23 @@ static int restore_extent(VmaReader *vmar, unsigned char *buf,
+ VmaRestoreState *rstate = &vmar->rstate[dev_id];
+ BlockBackend *target = NULL;
+
++ bool skip = rstate->skip;
++
+ if (dev_id != vmar->vmstate_stream) {
+ target = rstate->target;
+- if (!verify && !target) {
++ if (!verify && !target && !skip) {
+ error_setg(errp, "got wrong dev id %d", dev_id);
+ return -1;
+ }
+
+- if (vma_reader_get_bitmap(rstate, cluster_num)) {
+- error_setg(errp, "found duplicated cluster %zd for stream %s",
+- cluster_num, vmar->devinfo[dev_id].devname);
+- return -1;
++ if (!skip) {
++ if (vma_reader_get_bitmap(rstate, cluster_num)) {
++ error_setg(errp, "found duplicated cluster %zd for stream %s",
++ cluster_num, vmar->devinfo[dev_id].devname);
++ return -1;
++ }
++ vma_reader_set_bitmap(rstate, cluster_num, 1);
+ }
+- vma_reader_set_bitmap(rstate, cluster_num, 1);
+
+ max_sector = vmar->devinfo[dev_id].size/BDRV_SECTOR_SIZE;
+ } else {
+@@ -618,7 +626,7 @@ static int restore_extent(VmaReader *vmar, unsigned char *buf,
+ return -1;
+ }
+
+- if (!verify) {
++ if (!verify && !skip) {
+ int nb_sectors = end_sector - sector_num;
+ if (restore_write_data(vmar, dev_id, target, vmstate_fd,
+ buf + start, sector_num, nb_sectors,
+@@ -654,7 +662,7 @@ static int restore_extent(VmaReader *vmar, unsigned char *buf,
+ return -1;
+ }
+
+- if (!verify) {
++ if (!verify && !skip) {
+ int nb_sectors = end_sector - sector_num;
+ if (restore_write_data(vmar, dev_id, target, vmstate_fd,
+ buf + start, sector_num,
+@@ -679,7 +687,7 @@ static int restore_extent(VmaReader *vmar, unsigned char *buf,
+ vmar->partial_zero_cluster_data += zero_size;
+ }
+
+- if (rstate->write_zeroes && !verify) {
++ if (rstate->write_zeroes && !verify && !skip) {
+ if (restore_write_data(vmar, dev_id, target, vmstate_fd,
+ zero_vma_block, sector_num,
+ nb_sectors, errp) < 0) {
+@@ -850,7 +858,7 @@ int vma_reader_verify(VmaReader *vmar, bool verbose, Error **errp)
+
+ for (dev_id = 1; dev_id < 255; dev_id++) {
+ if (vma_reader_get_device_info(vmar, dev_id)) {
+- allocate_rstate(vmar, dev_id, NULL, false);
++ allocate_rstate(vmar, dev_id, NULL, false, false);
+ }
+ }
+
+diff --git a/vma.c b/vma.c
+index e8dffb43e0..e6e9ffc7fe 100644
+--- a/vma.c
++++ b/vma.c
+@@ -138,6 +138,7 @@ typedef struct RestoreMap {
+ char *throttling_group;
+ char *cache;
+ bool write_zero;
++ bool skip;
+ } RestoreMap;
+
+ static bool try_parse_option(char **line, const char *optname, char **out, const char *inbuf) {
+@@ -245,47 +246,61 @@ static int extract_content(int argc, char **argv)
+ char *bps = NULL;
+ char *group = NULL;
+ char *cache = NULL;
++ char *devname = NULL;
++ bool skip = false;
++ uint64_t bps_value = 0;
++ const char *path = NULL;
++ bool write_zero = true;
++
+ if (!line || line[0] == '\0' || !strcmp(line, "done\n")) {
+ break;
+ }
+ int len = strlen(line);
+ if (line[len - 1] == '\n') {
+ line[len - 1] = '\0';
+- if (len == 1) {
++ len = len - 1;
++ if (len == 0) {
+ break;
+ }
+ }
+
+- while (1) {
+- if (!try_parse_option(&line, "format", &format, inbuf) &&
+- !try_parse_option(&line, "throttling.bps", &bps, inbuf) &&
+- !try_parse_option(&line, "throttling.group", &group, inbuf) &&
+- !try_parse_option(&line, "cache", &cache, inbuf))
+- {
+- break;
++ if (strncmp(line, "skip", 4) == 0) {
++ if (len < 6 || line[4] != '=') {
++ g_error("read map failed - option 'skip' has no value ('%s')",
++ inbuf);
++ } else {
++ devname = line + 5;
++ skip = true;
++ }
++ } else {
++ while (1) {
++ if (!try_parse_option(&line, "format", &format, inbuf) &&
++ !try_parse_option(&line, "throttling.bps", &bps, inbuf) &&
++ !try_parse_option(&line, "throttling.group", &group, inbuf) &&
++ !try_parse_option(&line, "cache", &cache, inbuf))
++ {
++ break;
++ }
+ }
+- }
+
+- uint64_t bps_value = 0;
+- if (bps) {
+- bps_value = verify_u64(bps);
+- g_free(bps);
+- }
++ if (bps) {
++ bps_value = verify_u64(bps);
++ g_free(bps);
++ }
+
+- const char *path;
+- bool write_zero;
+- if (line[0] == '0' && line[1] == ':') {
+- path = line + 2;
+- write_zero = false;
+- } else if (line[0] == '1' && line[1] == ':') {
+- path = line + 2;
+- write_zero = true;
+- } else {
+- g_error("read map failed - parse error ('%s')", inbuf);
++ if (line[0] == '0' && line[1] == ':') {
++ path = line + 2;
++ write_zero = false;
++ } else if (line[0] == '1' && line[1] == ':') {
++ path = line + 2;
++ write_zero = true;
++ } else {
++ g_error("read map failed - parse error ('%s')", inbuf);
++ }
++
++ path = extract_devname(path, &devname, -1);
+ }
+
+- char *devname = NULL;
+- path = extract_devname(path, &devname, -1);
+ if (!devname) {
+ g_error("read map failed - no dev name specified ('%s')",
+ inbuf);
+@@ -299,6 +314,7 @@ static int extract_content(int argc, char **argv)
+ map->throttling_group = group;
+ map->cache = cache;
+ map->write_zero = write_zero;
++ map->skip = skip;
+
+ g_hash_table_insert(devmap, map->devname, map);
+
+@@ -328,6 +344,7 @@ static int extract_content(int argc, char **argv)
+ const char *cache = NULL;
+ int flags = BDRV_O_RDWR;
+ bool write_zero = true;
++ bool skip = false;
+
+ BlockBackend *blk = NULL;
+
+@@ -343,6 +360,7 @@ static int extract_content(int argc, char **argv)
+ throttling_group = map->throttling_group;
+ cache = map->cache;
+ write_zero = map->write_zero;
++ skip = map->skip;
+ } else {
+ devfn = g_strdup_printf("%s/tmp-disk-%s.raw",
+ dirname, di->devname);
+@@ -361,57 +379,60 @@ static int extract_content(int argc, char **argv)
+ write_zero = false;
+ }
+
+- size_t devlen = strlen(devfn);
+- QDict *options = NULL;
+- bool writethrough;
+- if (format) {
+- /* explicit format from commandline */
+- options = qdict_new();
+- qdict_put_str(options, "driver", format);
+- } else if ((devlen > 4 && strcmp(devfn+devlen-4, ".raw") == 0) ||
+- strncmp(devfn, "/dev/", 5) == 0)
+- {
+- /* This part is now deprecated for PVE as well (just as qemu
+- * deprecated not specifying an explicit raw format, too.
+- */
+- /* explicit raw format */
+- options = qdict_new();
+- qdict_put_str(options, "driver", "raw");
+- }
+- if (cache && bdrv_parse_cache_mode(cache, &flags, &writethrough)) {
+- g_error("invalid cache option: %s\n", cache);
+- }
++ if (!skip) {
++ size_t devlen = strlen(devfn);
++ QDict *options = NULL;
++ bool writethrough;
++ if (format) {
++ /* explicit format from commandline */
++ options = qdict_new();
++ qdict_put_str(options, "driver", format);
++ } else if ((devlen > 4 && strcmp(devfn+devlen-4, ".raw") == 0) ||
++ strncmp(devfn, "/dev/", 5) == 0)
++ {
++ /* This part is now deprecated for PVE as well (just as qemu
++ * deprecated not specifying an explicit raw format, too.
++ */
++ /* explicit raw format */
++ options = qdict_new();
++ qdict_put_str(options, "driver", "raw");
++ }
+
+- if (errp || !(blk = blk_new_open(devfn, NULL, options, flags, &errp))) {
+- g_error("can't open file %s - %s", devfn,
+- error_get_pretty(errp));
+- }
++ if (cache && bdrv_parse_cache_mode(cache, &flags, &writethrough)) {
++ g_error("invalid cache option: %s\n", cache);
++ }
+
+- if (cache) {
+- blk_set_enable_write_cache(blk, !writethrough);
+- }
++ if (errp || !(blk = blk_new_open(devfn, NULL, options, flags, &errp))) {
++ g_error("can't open file %s - %s", devfn,
++ error_get_pretty(errp));
++ }
+
+- if (throttling_group) {
+- blk_io_limits_enable(blk, throttling_group);
+- }
++ if (cache) {
++ blk_set_enable_write_cache(blk, !writethrough);
++ }
+
+- if (throttling_bps) {
+- if (!throttling_group) {
+- blk_io_limits_enable(blk, devfn);
++ if (throttling_group) {
++ blk_io_limits_enable(blk, throttling_group);
+ }
+
+- ThrottleConfig cfg;
+- throttle_config_init(&cfg);
+- cfg.buckets[THROTTLE_BPS_WRITE].avg = throttling_bps;
+- Error *err = NULL;
+- if (!throttle_is_valid(&cfg, &err)) {
+- error_report_err(err);
+- g_error("failed to apply throttling");
++ if (throttling_bps) {
++ if (!throttling_group) {
++ blk_io_limits_enable(blk, devfn);
++ }
++
++ ThrottleConfig cfg;
++ throttle_config_init(&cfg);
++ cfg.buckets[THROTTLE_BPS_WRITE].avg = throttling_bps;
++ Error *err = NULL;
++ if (!throttle_is_valid(&cfg, &err)) {
++ error_report_err(err);
++ g_error("failed to apply throttling");
++ }
++ blk_set_io_limits(blk, &cfg);
+ }
+- blk_set_io_limits(blk, &cfg);
+ }
+
+- if (vma_reader_register_bs(vmar, i, blk, write_zero, &errp) < 0) {
++ if (vma_reader_register_bs(vmar, i, blk, write_zero, skip, &errp) < 0) {
+ g_error("%s", error_get_pretty(errp));
+ }
+
+diff --git a/vma.h b/vma.h
+index c895c97f6d..1b62859165 100644
+--- a/vma.h
++++ b/vma.h
+@@ -142,7 +142,7 @@ GList *vma_reader_get_config_data(VmaReader *vmar);
+ VmaDeviceInfo *vma_reader_get_device_info(VmaReader *vmar, guint8 dev_id);
+ int vma_reader_register_bs(VmaReader *vmar, guint8 dev_id,
+ BlockBackend *target, bool write_zeroes,
+- Error **errp);
++ bool skip, Error **errp);
+ int vma_reader_restore(VmaReader *vmar, int vmstate_fd, bool verbose,
+ Error **errp);
+ int vma_reader_verify(VmaReader *vmar, bool verbose, Error **errp);
projects / pve-qemu.git / blobdiff