diff options
Diffstat (limited to 'block/blkdebug.c')
| -rw-r--r-- | block/blkdebug.c | 136 |
1 files changed, 92 insertions, 44 deletions
diff --git a/block/blkdebug.c b/block/blkdebug.c index 2c0b9b0ee8..8b67554bec 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -38,25 +38,27 @@ #include "qapi/qobject-input-visitor.h" #include "sysemu/qtest.h" +/* All APIs are thread-safe */ + typedef struct BDRVBlkdebugState { - int state; - int new_state; + /* IN: initialized in blkdebug_open() and never changed */ uint64_t align; uint64_t max_transfer; uint64_t opt_write_zero; uint64_t max_write_zero; uint64_t opt_discard; uint64_t max_discard; - + char *config_file; /* For blkdebug_refresh_filename() */ + /* initialized in blkdebug_parse_perms() */ uint64_t take_child_perms; uint64_t unshare_child_perms; - /* For blkdebug_refresh_filename() */ - char *config_file; - + /* State. Protected by lock */ + int state; QLIST_HEAD(, BlkdebugRule) rules[BLKDBG__MAX]; QSIMPLEQ_HEAD(, BlkdebugRule) active_rules; QLIST_HEAD(, BlkdebugSuspendedReq) suspended_reqs; + QemuMutex lock; } BDRVBlkdebugState; typedef struct BlkdebugAIOCB { @@ -65,8 +67,11 @@ typedef struct BlkdebugAIOCB { } BlkdebugAIOCB; typedef struct BlkdebugSuspendedReq { + /* IN: initialized in suspend_request() */ Coroutine *co; char *tag; + + /* List entry protected BDRVBlkdebugState's lock */ QLIST_ENTRY(BlkdebugSuspendedReq) next; } BlkdebugSuspendedReq; @@ -74,9 +79,11 @@ enum { ACTION_INJECT_ERROR, ACTION_SET_STATE, ACTION_SUSPEND, + ACTION__MAX, }; typedef struct BlkdebugRule { + /* IN: initialized in add_rule() or blkdebug_debug_breakpoint() */ BlkdebugEvent event; int action; int state; @@ -95,6 +102,8 @@ typedef struct BlkdebugRule { char *tag; } suspend; } options; + + /* List entries protected BDRVBlkdebugState's lock */ QLIST_ENTRY(BlkdebugRule) next; QSIMPLEQ_ENTRY(BlkdebugRule) active_next; } BlkdebugRule; @@ -244,11 +253,14 @@ static int add_rule(void *opaque, QemuOpts *opts, Error **errp) }; /* Add the rule */ + qemu_mutex_lock(&s->lock); QLIST_INSERT_HEAD(&s->rules[event], rule, next); + qemu_mutex_unlock(&s->lock); return 0; } +/* Called with lock held or from .bdrv_close */ static void remove_rule(BlkdebugRule *rule) { switch (rule->action) { @@ -467,6 +479,7 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags, int ret; uint64_t align; + qemu_mutex_init(&s->lock); opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort); if (!qemu_opts_absorb_qdict(opts, options, errp)) { ret = -EINVAL; @@ -567,6 +580,7 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags, ret = 0; out: if (ret < 0) { + qemu_mutex_destroy(&s->lock); g_free(s->config_file); } qemu_opts_del(opts); @@ -581,6 +595,7 @@ static int rule_check(BlockDriverState *bs, uint64_t offset, uint64_t bytes, int error; bool immediately; + qemu_mutex_lock(&s->lock); QSIMPLEQ_FOREACH(rule, &s->active_rules, active_next) { uint64_t inject_offset = rule->options.inject.offset; @@ -594,6 +609,7 @@ static int rule_check(BlockDriverState *bs, uint64_t offset, uint64_t bytes, } if (!rule || !rule->options.inject.error) { + qemu_mutex_unlock(&s->lock); return 0; } @@ -605,6 +621,7 @@ static int rule_check(BlockDriverState *bs, uint64_t offset, uint64_t bytes, remove_rule(rule); } + qemu_mutex_unlock(&s->lock); if (!immediately) { aio_co_schedule(qemu_get_current_aio_context(), qemu_coroutine_self()); qemu_coroutine_yield(); @@ -770,78 +787,80 @@ static void blkdebug_close(BlockDriverState *bs) } g_free(s->config_file); + qemu_mutex_destroy(&s->lock); } +/* Called with lock held. */ static void suspend_request(BlockDriverState *bs, BlkdebugRule *rule) { BDRVBlkdebugState *s = bs->opaque; - BlkdebugSuspendedReq r; + BlkdebugSuspendedReq *r; - r = (BlkdebugSuspendedReq) { - .co = qemu_coroutine_self(), - .tag = g_strdup(rule->options.suspend.tag), - }; + r = g_new(BlkdebugSuspendedReq, 1); + + r->co = qemu_coroutine_self(); + r->tag = g_strdup(rule->options.suspend.tag); remove_rule(rule); - QLIST_INSERT_HEAD(&s->suspended_reqs, &r, next); + QLIST_INSERT_HEAD(&s->suspended_reqs, r, next); if (!qtest_enabled()) { - printf("blkdebug: Suspended request '%s'\n", r.tag); - } - qemu_coroutine_yield(); - if (!qtest_enabled()) { - printf("blkdebug: Resuming request '%s'\n", r.tag); + printf("blkdebug: Suspended request '%s'\n", r->tag); } - - QLIST_REMOVE(&r, next); - g_free(r.tag); } -static bool process_rule(BlockDriverState *bs, struct BlkdebugRule *rule, - bool injected) +/* Called with lock held. */ +static void process_rule(BlockDriverState *bs, struct BlkdebugRule *rule, + int *action_count, int *new_state) { BDRVBlkdebugState *s = bs->opaque; /* Only process rules for the current state */ if (rule->state && rule->state != s->state) { - return injected; + return; } /* Take the action */ + action_count[rule->action]++; switch (rule->action) { case ACTION_INJECT_ERROR: - if (!injected) { + if (action_count[ACTION_INJECT_ERROR] == 1) { QSIMPLEQ_INIT(&s->active_rules); - injected = true; } QSIMPLEQ_INSERT_HEAD(&s->active_rules, rule, active_next); break; case ACTION_SET_STATE: - s->new_state = rule->options.set_state.new_state; + *new_state = rule->options.set_state.new_state; break; case ACTION_SUSPEND: suspend_request(bs, rule); break; } - return injected; } static void blkdebug_debug_event(BlockDriverState *bs, BlkdebugEvent event) { BDRVBlkdebugState *s = bs->opaque; struct BlkdebugRule *rule, *next; - bool injected; + int new_state; + int actions_count[ACTION__MAX] = { 0 }; assert((int)event >= 0 && event < BLKDBG__MAX); - injected = false; - s->new_state = s->state; - QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) { - injected = process_rule(bs, rule, injected); + WITH_QEMU_LOCK_GUARD(&s->lock) { + new_state = s->state; + QLIST_FOREACH_SAFE(rule, &s->rules[event], next, next) { + process_rule(bs, rule, actions_count, &new_state); + } + s->state = new_state; + } + + while (actions_count[ACTION_SUSPEND] > 0) { + qemu_coroutine_yield(); + actions_count[ACTION_SUSPEND]--; } - s->state = s->new_state; } static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event, @@ -864,33 +883,64 @@ static int blkdebug_debug_breakpoint(BlockDriverState *bs, const char *event, .options.suspend.tag = g_strdup(tag), }; + qemu_mutex_lock(&s->lock); QLIST_INSERT_HEAD(&s->rules[blkdebug_event], rule, next); + qemu_mutex_unlock(&s->lock); return 0; } -static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag) +/* Called with lock held. May temporarily release lock. */ +static int resume_req_by_tag(BDRVBlkdebugState *s, const char *tag, bool all) { - BDRVBlkdebugState *s = bs->opaque; - BlkdebugSuspendedReq *r, *next; + BlkdebugSuspendedReq *r; - QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, next) { +retry: + /* + * No need for _SAFE, since a different coroutine can remove another node + * (not the current one) in this list, and when the current one is removed + * the iteration starts back from beginning anyways. + */ + QLIST_FOREACH(r, &s->suspended_reqs, next) { if (!strcmp(r->tag, tag)) { - qemu_coroutine_enter(r->co); + Coroutine *co = r->co; + + if (!qtest_enabled()) { + printf("blkdebug: Resuming request '%s'\n", r->tag); + } + + QLIST_REMOVE(r, next); + g_free(r->tag); + g_free(r); + + qemu_mutex_unlock(&s->lock); + qemu_coroutine_enter(co); + qemu_mutex_lock(&s->lock); + + if (all) { + goto retry; + } return 0; } } return -ENOENT; } +static int blkdebug_debug_resume(BlockDriverState *bs, const char *tag) +{ + BDRVBlkdebugState *s = bs->opaque; + QEMU_LOCK_GUARD(&s->lock); + return resume_req_by_tag(s, tag, false); +} + static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs, const char *tag) { BDRVBlkdebugState *s = bs->opaque; - BlkdebugSuspendedReq *r, *r_next; BlkdebugRule *rule, *next; int i, ret = -ENOENT; + QEMU_LOCK_GUARD(&s->lock); for (i = 0; i < BLKDBG__MAX; i++) { QLIST_FOREACH_SAFE(rule, &s->rules[i], next, next) { if (rule->action == ACTION_SUSPEND && @@ -900,11 +950,8 @@ static int blkdebug_debug_remove_breakpoint(BlockDriverState *bs, } } } - QLIST_FOREACH_SAFE(r, &s->suspended_reqs, next, r_next) { - if (!strcmp(r->tag, tag)) { - qemu_coroutine_enter(r->co); - ret = 0; - } + if (resume_req_by_tag(s, tag, true) == 0) { + ret = 0; } return ret; } @@ -914,6 +961,7 @@ static bool blkdebug_debug_is_suspended(BlockDriverState *bs, const char *tag) BDRVBlkdebugState *s = bs->opaque; BlkdebugSuspendedReq *r; + QEMU_LOCK_GUARD(&s->lock); QLIST_FOREACH(r, &s->suspended_reqs, next) { if (!strcmp(r->tag, tag)) { return true; |