aboutsummaryrefslogtreecommitdiff
path: root/block/blkdebug.c
diff options
context:
space:
mode:
authorKevin Wolf <kwolf@redhat.com>2010-03-15 17:27:00 +0100
committerKevin Wolf <kwolf@redhat.com>2010-04-23 16:08:46 +0200
commit8b9b0cc2fd1b866c0ce6c7f7385d840aad8b4c2c (patch)
tree9c3d6512caa4ffd0366ca6fe6231042b3e89e943 /block/blkdebug.c
parent25920d6ad61b078a69b6ba401d4d6cd46ce83804 (diff)
blkdebug: Add events and rules
Block drivers can trigger a blkdebug event whenever they reach a place where it could be useful to inject an error for testing/debugging purposes. Rules are read from a blkdebug config file and describe which action is taken when an event is triggered. For now this is only injecting an error (with a few options) or changing the state (which is an integer). Rules can be declared to be active only in a specific state; this way later rules can distiguish on which path we came to trigger their event. Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block/blkdebug.c')
-rw-r--r--block/blkdebug.c250
1 files changed, 249 insertions, 1 deletions
diff --git a/block/blkdebug.c b/block/blkdebug.c
index dad3ac6e91..b813bfad57 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -46,6 +46,7 @@ typedef struct BlkdebugVars {
typedef struct BDRVBlkdebugState {
BlockDriverState *hd;
BlkdebugVars vars;
+ QLIST_HEAD(list, BlkdebugRule) rules[BLKDBG_EVENT_MAX];
} BDRVBlkdebugState;
typedef struct BlkdebugAIOCB {
@@ -61,16 +62,211 @@ static AIOPool blkdebug_aio_pool = {
.cancel = blkdebug_aio_cancel,
};
+enum {
+ ACTION_INJECT_ERROR,
+ ACTION_SET_STATE,
+};
+
+typedef struct BlkdebugRule {
+ BlkDebugEvent event;
+ int action;
+ int state;
+ union {
+ struct {
+ int error;
+ int immediately;
+ int once;
+ } inject;
+ struct {
+ int new_state;
+ } set_state;
+ } options;
+ QLIST_ENTRY(BlkdebugRule) next;
+} BlkdebugRule;
+
+static QemuOptsList inject_error_opts = {
+ .name = "inject-error",
+ .head = QTAILQ_HEAD_INITIALIZER(inject_error_opts.head),
+ .desc = {
+ {
+ .name = "event",
+ .type = QEMU_OPT_STRING,
+ },
+ {
+ .name = "state",
+ .type = QEMU_OPT_NUMBER,
+ },
+ {
+ .name = "errno",
+ .type = QEMU_OPT_NUMBER,
+ },
+ {
+ .name = "once",
+ .type = QEMU_OPT_BOOL,
+ },
+ {
+ .name = "immediately",
+ .type = QEMU_OPT_BOOL,
+ },
+ { /* end of list */ }
+ },
+};
+
+static QemuOptsList set_state_opts = {
+ .name = "set-state",
+ .head = QTAILQ_HEAD_INITIALIZER(inject_error_opts.head),
+ .desc = {
+ {
+ .name = "event",
+ .type = QEMU_OPT_STRING,
+ },
+ {
+ .name = "state",
+ .type = QEMU_OPT_NUMBER,
+ },
+ {
+ .name = "new_state",
+ .type = QEMU_OPT_NUMBER,
+ },
+ { /* end of list */ }
+ },
+};
+
+static QemuOptsList *config_groups[] = {
+ &inject_error_opts,
+ &set_state_opts,
+ NULL
+};
+
+static const char *event_names[BLKDBG_EVENT_MAX] = {
+};
+
+static int get_event_by_name(const char *name, BlkDebugEvent *event)
+{
+ int i;
+
+ for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
+ if (!strcmp(event_names[i], name)) {
+ *event = i;
+ return 0;
+ }
+ }
+
+ return -1;
+}
+
+struct add_rule_data {
+ BDRVBlkdebugState *s;
+ int action;
+};
+
+static int add_rule(QemuOpts *opts, void *opaque)
+{
+ struct add_rule_data *d = opaque;
+ BDRVBlkdebugState *s = d->s;
+ const char* event_name;
+ BlkDebugEvent event;
+ struct BlkdebugRule *rule;
+
+ /* Find the right event for the rule */
+ event_name = qemu_opt_get(opts, "event");
+ if (!event_name || get_event_by_name(event_name, &event) < 0) {
+ return -1;
+ }
+
+ /* Set attributes common for all actions */
+ rule = qemu_mallocz(sizeof(*rule));
+ *rule = (struct BlkdebugRule) {
+ .event = event,
+ .action = d->action,
+ .state = qemu_opt_get_number(opts, "state", 0),
+ };
+
+ /* Parse action-specific options */
+ switch (d->action) {
+ case ACTION_INJECT_ERROR:
+ rule->options.inject.error = qemu_opt_get_number(opts, "errno", EIO);
+ rule->options.inject.once = qemu_opt_get_bool(opts, "once", 0);
+ rule->options.inject.immediately =
+ qemu_opt_get_bool(opts, "immediately", 0);
+ break;
+
+ case ACTION_SET_STATE:
+ rule->options.set_state.new_state =
+ qemu_opt_get_number(opts, "new_state", 0);
+ break;
+ };
+
+ /* Add the rule */
+ QLIST_INSERT_HEAD(&s->rules[event], rule, next);
+
+ return 0;
+}
+
+static int read_config(BDRVBlkdebugState *s, const char *filename)
+{
+ FILE *f;
+ int ret;
+ struct add_rule_data d;
+
+ f = fopen(filename, "r");
+ if (f == NULL) {
+ return -errno;
+ }
+
+ ret = qemu_config_parse(f, config_groups, filename);
+ if (ret < 0) {
+ goto fail;
+ }
+
+ d.s = s;
+ d.action = ACTION_INJECT_ERROR;
+ qemu_opts_foreach(&inject_error_opts, add_rule, &d, 0);
+
+ d.action = ACTION_SET_STATE;
+ qemu_opts_foreach(&set_state_opts, add_rule, &d, 0);
+
+ ret = 0;
+fail:
+ fclose(f);
+ return ret;
+}
+
+/* Valid blkdebug filenames look like blkdebug:path/to/config:path/to/image */
static int blkdebug_open(BlockDriverState *bs, const char *filename, int flags)
{
BDRVBlkdebugState *s = bs->opaque;
+ int ret;
+ char *config, *c;
+ /* Parse the blkdebug: prefix */
if (strncmp(filename, "blkdebug:", strlen("blkdebug:"))) {
return -EINVAL;
}
filename += strlen("blkdebug:");
- return bdrv_file_open(&s->hd, filename, flags);
+ /* Read rules from config file */
+ c = strchr(filename, ':');
+ if (c == NULL) {
+ return -EINVAL;
+ }
+
+ config = strdup(filename);
+ config[c - filename] = '\0';
+ ret = read_config(s, config);
+ free(config);
+ if (ret < 0) {
+ return ret;
+ }
+ filename = c + 1;
+
+ /* Open the backing file */
+ ret = bdrv_file_open(&s->hd, filename, flags);
+ if (ret < 0) {
+ return ret;
+ }
+
+ return 0;
}
static void error_callback_bh(void *opaque)
@@ -146,6 +342,16 @@ static BlockDriverAIOCB *blkdebug_aio_writev(BlockDriverState *bs,
static void blkdebug_close(BlockDriverState *bs)
{
BDRVBlkdebugState *s = bs->opaque;
+ BlkdebugRule *rule, *next;
+ int i;
+
+ for (i = 0; i < BLKDBG_EVENT_MAX; i++) {
+ QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) {
+ QLIST_REMOVE(rule, next);
+ qemu_free(rule);
+ }
+ }
+
bdrv_delete(s->hd);
}
@@ -162,6 +368,46 @@ static BlockDriverAIOCB *blkdebug_aio_flush(BlockDriverState *bs,
return bdrv_aio_flush(s->hd, cb, opaque);
}
+static void process_rule(BlockDriverState *bs, struct BlkdebugRule *rule,
+ BlkdebugVars *old_vars)
+{
+ BDRVBlkdebugState *s = bs->opaque;
+ BlkdebugVars *vars = &s->vars;
+
+ /* Only process rules for the current state */
+ if (rule->state && rule->state != old_vars->state) {
+ return;
+ }
+
+ /* Take the action */
+ switch (rule->action) {
+ case ACTION_INJECT_ERROR:
+ vars->inject_errno = rule->options.inject.error;
+ vars->inject_once = rule->options.inject.once;
+ vars->inject_immediately = rule->options.inject.immediately;
+ break;
+
+ case ACTION_SET_STATE:
+ vars->state = rule->options.set_state.new_state;
+ break;
+ }
+}
+
+static void blkdebug_debug_event(BlockDriverState *bs, BlkDebugEvent event)
+{
+ BDRVBlkdebugState *s = bs->opaque;
+ struct BlkdebugRule *rule;
+ BlkdebugVars old_vars = s->vars;
+
+ if (event < 0 || event >= BLKDBG_EVENT_MAX) {
+ return;
+ }
+
+ QLIST_FOREACH(rule, &s->rules[event], next) {
+ process_rule(bs, rule, &old_vars);
+ }
+}
+
static BlockDriver bdrv_blkdebug = {
.format_name = "blkdebug",
.protocol_name = "blkdebug",
@@ -175,6 +421,8 @@ static BlockDriver bdrv_blkdebug = {
.bdrv_aio_readv = blkdebug_aio_readv,
.bdrv_aio_writev = blkdebug_aio_writev,
.bdrv_aio_flush = blkdebug_aio_flush,
+
+ .bdrv_debug_event = blkdebug_debug_event,
};
static void bdrv_blkdebug_init(void)