block: convert bdrv_check callback to coroutine_fn

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1516279431-30424-8-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

10 files changed, 103 insertions, 45 deletions

diff --git a/block.c b/block.c
index 603befb325..8f1c43d037 100644
--- a/block.c
+++ b/block.c
@@ -3455,17 +3455,54 @@ static void bdrv_delete(BlockDriverState *bs)
  * free of errors) or -errno when an internal error occurred. The results of the
  * check are stored in res.
  */
-int bdrv_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix)
+static int coroutine_fn bdrv_co_check(BlockDriverState *bs,
+                                      BdrvCheckResult *res, BdrvCheckMode fix)
 {
     if (bs->drv == NULL) {
         return -ENOMEDIUM;
     }
-    if (bs->drv->bdrv_check == NULL) {
+    if (bs->drv->bdrv_co_check == NULL) {
         return -ENOTSUP;
     }
 
     memset(res, 0, sizeof(*res));
-    return bs->drv->bdrv_check(bs, res, fix);
+    return bs->drv->bdrv_co_check(bs, res, fix);
+}
+
+typedef struct CheckCo {
+    BlockDriverState *bs;
+    BdrvCheckResult *res;
+    BdrvCheckMode fix;
+    int ret;
+} CheckCo;
+
+static void bdrv_check_co_entry(void *opaque)
+{
+    CheckCo *cco = opaque;
+    cco->ret = bdrv_co_check(cco->bs, cco->res, cco->fix);
+}
+
+int bdrv_check(BlockDriverState *bs,
+               BdrvCheckResult *res, BdrvCheckMode fix)
+{
+    Coroutine *co;
+    CheckCo cco = {
+        .bs = bs,
+        .res = res,
+        .ret = -EINPROGRESS,
+        .fix = fix,
+    };
+
+    if (qemu_in_coroutine()) {
+        /* Fast-path if already in coroutine context */
+        bdrv_check_co_entry(&cco);
+    } else {
+        co = qemu_coroutine_create(bdrv_check_co_entry, &cco);
+        qemu_coroutine_enter(co);
+        BDRV_POLL_WHILE(bs, cco.ret == -EINPROGRESS);
+    }
+
+    return cco.ret;
 }
 
 /*
diff --git a/block/parallels.c b/block/parallels.c
index 81085795c2..c13cb619e6 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -378,8 +378,9 @@ static coroutine_fn int parallels_co_readv(BlockDriverState *bs,
 }
 
 
-static int parallels_check(BlockDriverState *bs, BdrvCheckResult *res,
-                           BdrvCheckMode fix)
+static int coroutine_fn parallels_co_check(BlockDriverState *bs,
+                                           BdrvCheckResult *res,
+                                           BdrvCheckMode fix)
 {
     BDRVParallelsState *s = bs->opaque;
     int64_t size, prev_off, high_off;
@@ -394,6 +395,7 @@ static int parallels_check(BlockDriverState *bs, BdrvCheckResult *res,
         return size;
     }
 
+    qemu_co_mutex_lock(&s->lock);
     if (s->header_unclean) {
         fprintf(stderr, "%s image was not closed correctly\n",
                 fix & BDRV_FIX_ERRORS ? "Repairing" : "ERROR");
@@ -442,11 +444,12 @@ static int parallels_check(BlockDriverState *bs, BdrvCheckResult *res,
         prev_off = off;
     }
 
+    ret = 0;
     if (flush_bat) {
         ret = bdrv_pwrite_sync(bs->file, 0, s->header, s->header_size);
         if (ret < 0) {
             res->check_errors++;
-            return ret;
+            goto out;
         }
     }
 
@@ -465,13 +468,15 @@ static int parallels_check(BlockDriverState *bs, BdrvCheckResult *res,
             if (ret < 0) {
                 error_report_err(local_err);
                 res->check_errors++;
-                return ret;
+                goto out;
             }
             res->leaks_fixed += count;
         }
     }
 
-    return 0;
+out:
+    qemu_co_mutex_unlock(&s->lock);
+    return ret;
 }
 
 
@@ -799,7 +804,7 @@ static BlockDriver bdrv_parallels = {
     .bdrv_co_writev = parallels_co_writev,
     .supports_backing = true,
     .bdrv_co_create_opts = parallels_co_create_opts,
-    .bdrv_check     = parallels_check,
+    .bdrv_co_check  = parallels_co_check,
     .create_opts    = &parallels_create_opts,
 };
 
diff --git a/block/qcow2.c b/block/qcow2.c
index ac8703fa47..9fb00f2373 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -541,8 +541,9 @@ int qcow2_mark_consistent(BlockDriverState *bs)
     return 0;
 }
 
-static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result,
-                       BdrvCheckMode fix)
+static int coroutine_fn qcow2_co_check_locked(BlockDriverState *bs,
+                                              BdrvCheckResult *result,
+                                              BdrvCheckMode fix)
 {
     int ret = qcow2_check_refcounts(bs, result, fix);
     if (ret < 0) {
@@ -559,6 +560,19 @@ static int qcow2_check(BlockDriverState *bs, BdrvCheckResult *result,
     return ret;
 }
 
+static int coroutine_fn qcow2_co_check(BlockDriverState *bs,
+                                       BdrvCheckResult *result,
+                                       BdrvCheckMode fix)
+{
+    BDRVQcow2State *s = bs->opaque;
+    int ret;
+
+    qemu_co_mutex_lock(&s->lock);
+    ret = qcow2_co_check_locked(bs, result, fix);
+    qemu_co_mutex_unlock(&s->lock);
+    return ret;
+}
+
 static int validate_table_offset(BlockDriverState *bs, uint64_t offset,
                                  uint64_t entries, size_t entry_len)
 {
@@ -1506,7 +1520,8 @@ static int coroutine_fn qcow2_do_open(BlockDriverState *bs, QDict *options,
         (s->incompatible_features & QCOW2_INCOMPAT_DIRTY)) {
         BdrvCheckResult result = {0};
 
-        ret = qcow2_check(bs, &result, BDRV_FIX_ERRORS | BDRV_FIX_LEAKS);
+        ret = qcow2_co_check_locked(bs, &result,
+                                    BDRV_FIX_ERRORS | BDRV_FIX_LEAKS);
         if (ret < 0 || result.check_errors) {
             if (ret >= 0) {
                 ret = -EIO;
@@ -4413,7 +4428,7 @@ BlockDriver bdrv_qcow2 = {
     .bdrv_inactivate            = qcow2_inactivate,
 
     .create_opts         = &qcow2_create_opts,
-    .bdrv_check          = qcow2_check,
+    .bdrv_co_check       = qcow2_co_check,
     .bdrv_amend_options  = qcow2_amend_options,
 
     .bdrv_detach_aio_context  = qcow2_detach_aio_context,
diff --git a/block/qed-check.c b/block/qed-check.c
index dcd4f036b8..0edac03159 100644
--- a/block/qed-check.c
+++ b/block/qed-check.c
@@ -217,6 +217,7 @@ static void qed_check_mark_clean(BDRVQEDState *s, BdrvCheckResult *result)
     qed_write_header_sync(s);
 }
 
+/* Called with table_lock held.  */
 int qed_check(BDRVQEDState *s, BdrvCheckResult *result, bool fix)
 {
     QEDCheck check = {
diff --git a/block/qed-table.c b/block/qed-table.c
index eead8b0fc7..7df5680adb 100644
--- a/block/qed-table.c
+++ b/block/qed-table.c
@@ -18,7 +18,7 @@
 #include "qed.h"
 #include "qemu/bswap.h"
 
-/* Called either from qed_check or with table_lock held.  */
+/* Called with table_lock held.  */
 static int qed_read_table(BDRVQEDState *s, uint64_t offset, QEDTable *table)
 {
     QEMUIOVector qiov;
@@ -33,13 +33,9 @@ static int qed_read_table(BDRVQEDState *s, uint64_t offset, QEDTable *table)
 
     trace_qed_read_table(s, offset, table);
 
-    if (qemu_in_coroutine()) {
-        qemu_co_mutex_unlock(&s->table_lock);
-    }
+    qemu_co_mutex_unlock(&s->table_lock);
     ret = bdrv_preadv(s->bs->file, offset, &qiov);
-    if (qemu_in_coroutine()) {
-        qemu_co_mutex_lock(&s->table_lock);
-    }
+    qemu_co_mutex_lock(&s->table_lock);
     if (ret < 0) {
         goto out;
     }
@@ -67,7 +63,7 @@ out:
  * @n:          Number of elements
  * @flush:      Whether or not to sync to disk
  *
- * Called either from qed_check or with table_lock held.
+ * Called with table_lock held.
  */
 static int qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
                            unsigned int index, unsigned int n, bool flush)
@@ -104,13 +100,9 @@ static int qed_write_table(BDRVQEDState *s, uint64_t offset, QEDTable *table,
     /* Adjust for offset into table */
     offset += start * sizeof(uint64_t);
 
-    if (qemu_in_coroutine()) {
-        qemu_co_mutex_unlock(&s->table_lock);
-    }
+    qemu_co_mutex_unlock(&s->table_lock);
     ret = bdrv_pwritev(s->bs->file, offset, &qiov);
-    if (qemu_in_coroutine()) {
-        qemu_co_mutex_lock(&s->table_lock);
-    }
+    qemu_co_mutex_lock(&s->table_lock);
     trace_qed_write_table_cb(s, table, flush, ret);
     if (ret < 0) {
         goto out;
@@ -134,7 +126,7 @@ int qed_read_l1_table_sync(BDRVQEDState *s)
     return qed_read_table(s, s->header.l1_table_offset, s->l1_table);
 }
 
-/* Called either from qed_check or with table_lock held.  */
+/* Called with table_lock held.  */
 int qed_write_l1_table(BDRVQEDState *s, unsigned int index, unsigned int n)
 {
     BLKDBG_EVENT(s->bs->file, BLKDBG_L1_UPDATE);
@@ -148,7 +140,7 @@ int qed_write_l1_table_sync(BDRVQEDState *s, unsigned int index,
     return qed_write_l1_table(s, index, n);
 }
 
-/* Called either from qed_check or with table_lock held.  */
+/* Called with table_lock held.  */
 int qed_read_l2_table(BDRVQEDState *s, QEDRequest *request, uint64_t offset)
 {
     int ret;
@@ -191,7 +183,7 @@ int qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request, uint64_t offset
     return qed_read_l2_table(s, request, offset);
 }
 
-/* Called either from qed_check or with table_lock held.  */
+/* Called with table_lock held.  */
 int qed_write_l2_table(BDRVQEDState *s, QEDRequest *request,
                        unsigned int index, unsigned int n, bool flush)
 {
diff --git a/block/qed.c b/block/qed.c
index 5a5414bfc3..5e6a6bfaa0 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -1544,12 +1544,17 @@ static void coroutine_fn bdrv_qed_co_invalidate_cache(BlockDriverState *bs,
     }
 }
 
-static int bdrv_qed_check(BlockDriverState *bs, BdrvCheckResult *result,
-                          BdrvCheckMode fix)
+static int bdrv_qed_co_check(BlockDriverState *bs, BdrvCheckResult *result,
+                             BdrvCheckMode fix)
 {
     BDRVQEDState *s = bs->opaque;
+    int ret;
 
-    return qed_check(s, result, !!fix);
+    qemu_co_mutex_lock(&s->table_lock);
+    ret = qed_check(s, result, !!fix);
+    qemu_co_mutex_unlock(&s->table_lock);
+
+    return ret;
 }
 
 static QemuOptsList qed_create_opts = {
@@ -1609,7 +1614,7 @@ static BlockDriver bdrv_qed = {
     .bdrv_refresh_limits      = bdrv_qed_refresh_limits,
     .bdrv_change_backing_file = bdrv_qed_change_backing_file,
     .bdrv_co_invalidate_cache = bdrv_qed_co_invalidate_cache,
-    .bdrv_check               = bdrv_qed_check,
+    .bdrv_co_check            = bdrv_qed_co_check,
     .bdrv_detach_aio_context  = bdrv_qed_detach_aio_context,
     .bdrv_attach_aio_context  = bdrv_qed_attach_aio_context,
     .bdrv_co_drain_begin      = bdrv_qed_co_drain_begin,
diff --git a/block/vdi.c b/block/vdi.c
index 68592cc58d..2b5ddd0666 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -263,8 +263,8 @@ static void vdi_header_print(VdiHeader *header)
 }
 #endif
 
-static int vdi_check(BlockDriverState *bs, BdrvCheckResult *res,
-                     BdrvCheckMode fix)
+static int coroutine_fn vdi_co_check(BlockDriverState *bs, BdrvCheckResult *res,
+                                     BdrvCheckMode fix)
 {
     /* TODO: additional checks possible. */
     BDRVVdiState *s = (BDRVVdiState *)bs->opaque;
@@ -908,7 +908,7 @@ static BlockDriver bdrv_vdi = {
     .bdrv_get_info = vdi_get_info,
 
     .create_opts = &vdi_create_opts,
-    .bdrv_check = vdi_check,
+    .bdrv_co_check = vdi_co_check,
 };
 
 static void bdrv_vdi_init(void)
diff --git a/block/vhdx.c b/block/vhdx.c
index 3fbff5048b..d82350d07c 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -1944,8 +1944,9 @@ exit:
  * r/w and any log has already been replayed, so there is nothing (currently)
  * for us to do here
  */
-static int vhdx_check(BlockDriverState *bs, BdrvCheckResult *result,
-                       BdrvCheckMode fix)
+static int coroutine_fn vhdx_co_check(BlockDriverState *bs,
+                                      BdrvCheckResult *result,
+                                      BdrvCheckMode fix)
 {
     BDRVVHDXState *s = bs->opaque;
 
@@ -2006,7 +2007,7 @@ static BlockDriver bdrv_vhdx = {
     .bdrv_co_writev         = vhdx_co_writev,
     .bdrv_co_create_opts    = vhdx_co_create_opts,
     .bdrv_get_info          = vhdx_get_info,
-    .bdrv_check             = vhdx_check,
+    .bdrv_co_check          = vhdx_co_check,
     .bdrv_has_zero_init     = bdrv_has_zero_init_1,
 
     .create_opts            = &vhdx_create_opts,
diff --git a/block/vmdk.c b/block/vmdk.c
index 67342ed69b..f94c49a9c0 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -2221,8 +2221,9 @@ static ImageInfo *vmdk_get_extent_info(VmdkExtent *extent)
     return info;
 }
 
-static int vmdk_check(BlockDriverState *bs, BdrvCheckResult *result,
-                      BdrvCheckMode fix)
+static int coroutine_fn vmdk_co_check(BlockDriverState *bs,
+                                      BdrvCheckResult *result,
+                                      BdrvCheckMode fix)
 {
     BDRVVmdkState *s = bs->opaque;
     VmdkExtent *extent = NULL;
@@ -2391,7 +2392,7 @@ static BlockDriver bdrv_vmdk = {
     .instance_size                = sizeof(BDRVVmdkState),
     .bdrv_probe                   = vmdk_probe,
     .bdrv_open                    = vmdk_open,
-    .bdrv_check                   = vmdk_check,
+    .bdrv_co_check                = vmdk_co_check,
     .bdrv_reopen_prepare          = vmdk_reopen_prepare,
     .bdrv_child_perm              = bdrv_format_default_perms,
     .bdrv_co_preadv               = vmdk_co_preadv,
diff --git a/include/block/block_int.h b/include/block/block_int.h
index e391cae53b..a84cc04d55 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -307,8 +307,9 @@ struct BlockDriver {
      * Returns 0 for completed check, -errno for internal errors.
      * The check results are stored in result.
      */
-    int (*bdrv_check)(BlockDriverState *bs, BdrvCheckResult *result,
-        BdrvCheckMode fix);
+    int coroutine_fn (*bdrv_co_check)(BlockDriverState *bs,
+                                      BdrvCheckResult *result,
+                                      BdrvCheckMode fix);
 
     int (*bdrv_amend_options)(BlockDriverState *bs, QemuOpts *opts,
                               BlockDriverAmendStatusCB *status_cb,