qcow2: Trigger blkdebug events

This adds blkdebug events to qcow2 to allow injecting I/O errors in specific
places.
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block.h

@@ -210,6 +210,50 @@ int64_t bdrv_get_dirty_count(BlockDriverState *bs);
 
 
 typedef enum {
+    BLKDBG_L1_UPDATE,
+
+    BLKDBG_L1_GROW_ALLOC_TABLE,
+    BLKDBG_L1_GROW_WRITE_TABLE,
+    BLKDBG_L1_GROW_ACTIVATE_TABLE,
+
+    BLKDBG_L2_LOAD,
+    BLKDBG_L2_UPDATE,
+    BLKDBG_L2_UPDATE_COMPRESSED,
+    BLKDBG_L2_ALLOC_COW_READ,
+    BLKDBG_L2_ALLOC_WRITE,
+
+    BLKDBG_READ,
+    BLKDBG_READ_AIO,
+    BLKDBG_READ_BACKING,
+    BLKDBG_READ_BACKING_AIO,
+    BLKDBG_READ_COMPRESSED,
+
+    BLKDBG_WRITE_AIO,
+    BLKDBG_WRITE_COMPRESSED,
+
+    BLKDBG_VMSTATE_LOAD,
+    BLKDBG_VMSTATE_SAVE,
+
+    BLKDBG_COW_READ,
+    BLKDBG_COW_WRITE,
+
+    BLKDBG_REFTABLE_LOAD,
+    BLKDBG_REFTABLE_GROW,
+
+    BLKDBG_REFBLOCK_LOAD,
+    BLKDBG_REFBLOCK_UPDATE,
+    BLKDBG_REFBLOCK_UPDATE_PART,
+    BLKDBG_REFBLOCK_ALLOC,
+    BLKDBG_REFBLOCK_ALLOC_HOOKUP,
+    BLKDBG_REFBLOCK_ALLOC_WRITE,
+    BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS,
+    BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE,
+    BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE,
+
+    BLKDBG_CLUSTER_ALLOC,
+    BLKDBG_CLUSTER_ALLOC_BYTES,
+    BLKDBG_CLUSTER_FREE,
+
     BLKDBG_EVENT_MAX,
 } BlkDebugEvent;
 

block/blkdebug.c

@@ -139,6 +139,48 @@ static QemuOptsList *config_groups[] = {
 };
 
 static const char *event_names[BLKDBG_EVENT_MAX] = {
+    [BLKDBG_L1_UPDATE]                      = "l1_update",
+    [BLKDBG_L1_GROW_ALLOC_TABLE]            = "l1_grow.alloc_table",
+    [BLKDBG_L1_GROW_WRITE_TABLE]            = "l1_grow.write_table",
+    [BLKDBG_L1_GROW_ACTIVATE_TABLE]         = "l1_grow.activate_table",
+
+    [BLKDBG_L2_LOAD]                        = "l2_load",
+    [BLKDBG_L2_UPDATE]                      = "l2_update",
+    [BLKDBG_L2_UPDATE_COMPRESSED]           = "l2_update_compressed",
+    [BLKDBG_L2_ALLOC_COW_READ]              = "l2_alloc.cow_read",
+    [BLKDBG_L2_ALLOC_WRITE]                 = "l2_alloc.write",
+
+    [BLKDBG_READ]                           = "read",
+    [BLKDBG_READ_AIO]                       = "read_aio",
+    [BLKDBG_READ_BACKING]                   = "read_backing",
+    [BLKDBG_READ_BACKING_AIO]               = "read_backing_aio",
+    [BLKDBG_READ_COMPRESSED]                = "read_compressed",
+
+    [BLKDBG_WRITE_AIO]                      = "write_aio",
+    [BLKDBG_WRITE_COMPRESSED]               = "write_compressed",
+
+    [BLKDBG_VMSTATE_LOAD]                   = "vmstate_load",
+    [BLKDBG_VMSTATE_SAVE]                   = "vmstate_save",
+
+    [BLKDBG_COW_READ]                       = "cow_read",
+    [BLKDBG_COW_WRITE]                      = "cow_write",
+
+    [BLKDBG_REFTABLE_LOAD]                  = "reftable_load",
+    [BLKDBG_REFTABLE_GROW]                  = "reftable_grow",
+
+    [BLKDBG_REFBLOCK_LOAD]                  = "refblock_load",
+    [BLKDBG_REFBLOCK_UPDATE]                = "refblock_update",
+    [BLKDBG_REFBLOCK_UPDATE_PART]           = "refblock_update_part",
+    [BLKDBG_REFBLOCK_ALLOC]                 = "refblock_alloc",
+    [BLKDBG_REFBLOCK_ALLOC_HOOKUP]          = "refblock_alloc.hookup",
+    [BLKDBG_REFBLOCK_ALLOC_WRITE]           = "refblock_alloc.write",
+    [BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS]    = "refblock_alloc.write_blocks",
+    [BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE]     = "refblock_alloc.write_table",
+    [BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE]    = "refblock_alloc.switch_table",
+
+    [BLKDBG_CLUSTER_ALLOC]                  = "cluster_alloc",
+    [BLKDBG_CLUSTER_ALLOC_BYTES]            = "cluster_alloc_bytes",
+    [BLKDBG_CLUSTER_FREE]                   = "cluster_free",
 };
 
 static int get_event_by_name(const char *name, BlkDebugEvent *event)

block/qcow2-cluster.c

@@ -54,12 +54,14 @@ int qcow2_grow_l1_table(BlockDriverState *bs, int min_size)
     memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
 
     /* write new table (align to cluster) */
+    BLKDBG_EVENT(s->hd, BLKDBG_L1_GROW_ALLOC_TABLE);
     new_l1_table_offset = qcow2_alloc_clusters(bs, new_l1_size2);
     if (new_l1_table_offset < 0) {
         qemu_free(new_l1_table);
         return new_l1_table_offset;
     }
 
+    BLKDBG_EVENT(s->hd, BLKDBG_L1_GROW_WRITE_TABLE);
     for(i = 0; i < s->l1_size; i++)
         new_l1_table[i] = cpu_to_be64(new_l1_table[i]);
     ret = bdrv_pwrite(s->hd, new_l1_table_offset, new_l1_table, new_l1_size2);
@@ -69,6 +71,7 @@ int qcow2_grow_l1_table(BlockDriverState *bs, int min_size)
         new_l1_table[i] = be64_to_cpu(new_l1_table[i]);
 
     /* set new table */
+    BLKDBG_EVENT(s->hd, BLKDBG_L1_GROW_ACTIVATE_TABLE);
     cpu_to_be32w((uint32_t*)data, new_l1_size);
     cpu_to_be64w((uint64_t*)(data + 4), new_l1_table_offset);
     ret = bdrv_pwrite(s->hd, offsetof(QCowHeader, l1_size), data,sizeof(data));
@@ -170,6 +173,8 @@ static uint64_t *l2_load(BlockDriverState *bs, uint64_t l2_offset)
 
     min_index = l2_cache_new_entry(bs);
     l2_table = s->l2_cache + (min_index << s->l2_bits);
+
+    BLKDBG_EVENT(s->hd, BLKDBG_L2_LOAD);
     if (bdrv_pread(s->hd, l2_offset, l2_table, s->l2_size * sizeof(uint64_t)) !=
         s->l2_size * sizeof(uint64_t))
         return NULL;
@@ -195,6 +200,7 @@ static int write_l1_entry(BDRVQcowState *s, int l1_index)
         buf[i] = cpu_to_be64(s->l1_table[l1_start_index + i]);
     }
 
+    BLKDBG_EVENT(s->hd, BLKDBG_L1_UPDATE);
     if (bdrv_pwrite(s->hd, s->l1_table_offset + 8 * l1_start_index,
         buf, sizeof(buf)) != sizeof(buf))
     {
@@ -248,12 +254,14 @@ static uint64_t *l2_allocate(BlockDriverState *bs, int l1_index)
         memset(l2_table, 0, s->l2_size * sizeof(uint64_t));
     } else {
         /* if there was an old l2 table, read it from the disk */
+        BLKDBG_EVENT(s->hd, BLKDBG_L2_ALLOC_COW_READ);
         if (bdrv_pread(s->hd, old_l2_offset,
                        l2_table, s->l2_size * sizeof(uint64_t)) !=
             s->l2_size * sizeof(uint64_t))
             return NULL;
     }
     /* write the l2 table to the file */
+    BLKDBG_EVENT(s->hd, BLKDBG_L2_ALLOC_WRITE);
     if (bdrv_pwrite(s->hd, l2_offset,
                     l2_table, s->l2_size * sizeof(uint64_t)) !=
         s->l2_size * sizeof(uint64_t))
@@ -335,6 +343,7 @@ static int qcow_read(BlockDriverState *bs, int64_t sector_num,
                 /* read from the base image */
                 n1 = qcow2_backing_read1(bs->backing_hd, sector_num, buf, n);
                 if (n1 > 0) {
+                    BLKDBG_EVENT(s->hd, BLKDBG_READ_BACKING);
                     ret = bdrv_read(bs->backing_hd, sector_num, buf, n1);
                     if (ret < 0)
                         return -1;
@@ -347,6 +356,7 @@ static int qcow_read(BlockDriverState *bs, int64_t sector_num,
                 return -1;
             memcpy(buf, s->cluster_cache + index_in_cluster * 512, 512 * n);
         } else {
+            BLKDBG_EVENT(s->hd, BLKDBG_READ);
             ret = bdrv_pread(s->hd, cluster_offset + index_in_cluster * 512, buf, n * 512);
             if (ret != n * 512)
                 return -1;
@@ -371,6 +381,7 @@ static int copy_sectors(BlockDriverState *bs, uint64_t start_sect,
     n = n_end - n_start;
     if (n <= 0)
         return 0;
+    BLKDBG_EVENT(s->hd, BLKDBG_COW_READ);
     ret = qcow_read(bs, start_sect + n_start, s->cluster_data, n);
     if (ret < 0)
         return ret;
@@ -380,6 +391,7 @@ static int copy_sectors(BlockDriverState *bs, uint64_t start_sect,
                         s->cluster_data, n, 1,
                         &s->aes_encrypt_key);
     }
+    BLKDBG_EVENT(s->hd, BLKDBG_COW_WRITE);
     ret = bdrv_write(s->hd, (cluster_offset >> 9) + n_start,
                      s->cluster_data, n);
     if (ret < 0)
@@ -592,6 +604,7 @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
 
     /* compressed clusters never have the copied flag */
 
+    BLKDBG_EVENT(s->hd, BLKDBG_L2_UPDATE_COMPRESSED);
     l2_table[l2_index] = cpu_to_be64(cluster_offset);
     if (bdrv_pwrite(s->hd,
                     l2_offset + l2_index * sizeof(uint64_t),
@@ -615,6 +628,7 @@ static int write_l2_entries(BDRVQcowState *s, uint64_t *l2_table,
     int end_offset = (8 * (l2_index + num) + 511) & ~511;
     size_t len = end_offset - start_offset;
 
+    BLKDBG_EVENT(s->hd, BLKDBG_L2_UPDATE);
     if (bdrv_pwrite(s->hd, l2_offset + start_offset, &l2_table[l2_start_index],
         len) != len)
     {
@@ -866,6 +880,7 @@ int qcow2_decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset)
         nb_csectors = ((cluster_offset >> s->csize_shift) & s->csize_mask) + 1;
         sector_offset = coffset & 511;
         csize = nb_csectors * 512 - sector_offset;
+        BLKDBG_EVENT(s->hd, BLKDBG_READ_COMPRESSED);
         ret = bdrv_read(s->hd, coffset >> 9, s->cluster_data, nb_csectors);
         if (ret < 0) {
             return -1;

block/qcow2-refcount.c

@@ -42,6 +42,7 @@ static int write_refcount_block(BDRVQcowState *s)
         return 0;
     }
 
+    BLKDBG_EVENT(s->hd, BLKDBG_REFBLOCK_UPDATE);
     if (bdrv_pwrite(s->hd, s->refcount_block_cache_offset,
             s->refcount_block_cache, size) != size)
     {
@@ -63,6 +64,7 @@ int qcow2_refcount_init(BlockDriverState *bs)
     refcount_table_size2 = s->refcount_table_size * sizeof(uint64_t);
     s->refcount_table = qemu_malloc(refcount_table_size2);
     if (s->refcount_table_size > 0) {
+        BLKDBG_EVENT(s->hd, BLKDBG_REFTABLE_LOAD);
         ret = bdrv_pread(s->hd, s->refcount_table_offset,
                          s->refcount_table, refcount_table_size2);
         if (ret != refcount_table_size2)
@@ -93,6 +95,7 @@ static int load_refcount_block(BlockDriverState *bs,
         write_refcount_block(s);
     }
 
+    BLKDBG_EVENT(s->hd, BLKDBG_REFBLOCK_LOAD);
     ret = bdrv_pread(s->hd, refcount_block_offset, s->refcount_block_cache,
                      s->cluster_size);
     if (ret != s->cluster_size)
@@ -164,6 +167,8 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
     unsigned int refcount_table_index;
     int ret;
 
+    BLKDBG_EVENT(s->hd, BLKDBG_REFBLOCK_ALLOC);
+
     /* Find the refcount block for the given cluster */
     refcount_table_index = cluster_index >> (s->cluster_bits - REFCOUNT_SHIFT);
 
@@ -239,6 +244,7 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
     }
 
     /* Now the new refcount block needs to be written to disk */
+    BLKDBG_EVENT(s->hd, BLKDBG_REFBLOCK_ALLOC_WRITE);
     ret = bdrv_pwrite(s->hd, new_block, s->refcount_block_cache,
         s->cluster_size);
     if (ret < 0) {
@@ -248,6 +254,7 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
     /* If the refcount table is big enough, just hook the block up there */
     if (refcount_table_index < s->refcount_table_size) {
         uint64_t data64 = cpu_to_be64(new_block);
+        BLKDBG_EVENT(s->hd, BLKDBG_REFBLOCK_ALLOC_HOOKUP);
         ret = bdrv_pwrite(s->hd,
             s->refcount_table_offset + refcount_table_index * sizeof(uint64_t),
             &data64, sizeof(data64));
@@ -270,6 +277,8 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
      * refcount table at once without producing an inconsistent state in
      * between.
      */
+    BLKDBG_EVENT(s->hd, BLKDBG_REFTABLE_GROW);
+
     /* Calculate the number of refcount blocks needed so far */
     uint64_t refcount_block_clusters = 1 << (s->cluster_bits - REFCOUNT_SHIFT);
     uint64_t blocks_used = (s->free_cluster_index +
@@ -325,6 +334,7 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
     }
 
     /* Write refcount blocks to disk */
+    BLKDBG_EVENT(s->hd, BLKDBG_REFBLOCK_ALLOC_WRITE_BLOCKS);
     ret = bdrv_pwrite(s->hd, meta_offset, new_blocks,
         blocks_clusters * s->cluster_size);
     qemu_free(new_blocks);
@@ -337,6 +347,7 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
         cpu_to_be64s(&new_table[i]);
     }
 
+    BLKDBG_EVENT(s->hd, BLKDBG_REFBLOCK_ALLOC_WRITE_TABLE);
     ret = bdrv_pwrite(s->hd, table_offset, new_table,
         table_size * sizeof(uint64_t));
     if (ret < 0) {
@@ -351,6 +362,7 @@ static int64_t alloc_refcount_block(BlockDriverState *bs, int64_t cluster_index)
     uint8_t data[12];
     cpu_to_be64w((uint64_t*)data, table_offset);
     cpu_to_be32w((uint32_t*)(data + 8), table_clusters);
+    BLKDBG_EVENT(s->hd, BLKDBG_REFBLOCK_ALLOC_SWITCH_TABLE);
     ret = bdrv_pwrite(s->hd, offsetof(QCowHeader, refcount_table_offset),
         data, sizeof(data));
     if (ret < 0) {
@@ -400,6 +412,7 @@ static int write_refcount_block_entries(BDRVQcowState *s,
         & ~(REFCOUNTS_PER_SECTOR - 1);
 
     size = (last_index - first_index) << REFCOUNT_SHIFT;
+    BLKDBG_EVENT(s->hd, BLKDBG_REFBLOCK_UPDATE_PART);
     if (bdrv_pwrite(s->hd,
         refcount_block_offset + (first_index << REFCOUNT_SHIFT),
         &s->refcount_block_cache[first_index], size) != size)
@@ -555,9 +568,11 @@ retry:
 
 int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size)
 {
+    BDRVQcowState *s = bs->opaque;
     int64_t offset;
     int ret;
 
+    BLKDBG_EVENT(s->hd, BLKDBG_CLUSTER_ALLOC);
     offset = alloc_clusters_noref(bs, size);
     ret = update_refcount(bs, offset, size, 1);
     if (ret < 0) {
@@ -574,6 +589,7 @@ int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
     int64_t offset, cluster_offset;
     int free_in_cluster;
 
+    BLKDBG_EVENT(s->hd, BLKDBG_CLUSTER_ALLOC_BYTES);
     assert(size > 0 && size <= s->cluster_size);
     if (s->free_byte_offset == 0) {
         s->free_byte_offset = qcow2_alloc_clusters(bs, s->cluster_size);
@@ -615,8 +631,10 @@ int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
 void qcow2_free_clusters(BlockDriverState *bs,
                           int64_t offset, int64_t size)
 {
+    BDRVQcowState *s = bs->opaque;
     int ret;
 
+    BLKDBG_EVENT(s->hd, BLKDBG_CLUSTER_FREE);
     ret = update_refcount(bs, offset, size, -1);
     if (ret < 0) {
         fprintf(stderr, "qcow2_free_clusters failed: %s\n", strerror(-ret));

block/qcow2.c

@@ -429,6 +429,7 @@ static void qcow_aio_read_cb(void *opaque, int ret)
                 acb->hd_iov.iov_base = (void *)acb->buf;
                 acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
                 qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
+                BLKDBG_EVENT(s->hd, BLKDBG_READ_BACKING_AIO);
                 acb->hd_aiocb = bdrv_aio_readv(bs->backing_hd, acb->sector_num,
                                     &acb->hd_qiov, acb->cur_nr_sectors,
 				    qcow_aio_read_cb, acb);
@@ -464,6 +465,7 @@ static void qcow_aio_read_cb(void *opaque, int ret)
         acb->hd_iov.iov_base = (void *)acb->buf;
         acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
         qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
+        BLKDBG_EVENT(s->hd, BLKDBG_READ_AIO);
         acb->hd_aiocb = bdrv_aio_readv(s->hd,
                             (acb->cluster_offset >> 9) + index_in_cluster,
                             &acb->hd_qiov, acb->cur_nr_sectors,
@@ -619,6 +621,7 @@ static void qcow_aio_write_cb(void *opaque, int ret)
     acb->hd_iov.iov_base = (void *)src_buf;
     acb->hd_iov.iov_len = acb->cur_nr_sectors * 512;
     qemu_iovec_init_external(&acb->hd_qiov, &acb->hd_iov, 1);
+    BLKDBG_EVENT(s->hd, BLKDBG_WRITE_AIO);
     acb->hd_aiocb = bdrv_aio_writev(s->hd,
                                     (acb->cluster_offset >> 9) + index_in_cluster,
                                     &acb->hd_qiov, acb->cur_nr_sectors,
@@ -1141,6 +1144,7 @@ static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num,
         if (!cluster_offset)
             return -1;
         cluster_offset &= s->cluster_offset_mask;
+        BLKDBG_EVENT(s->hd, BLKDBG_WRITE_COMPRESSED);
         if (bdrv_pwrite(s->hd, cluster_offset, out_buf, out_len) != out_len) {
             qemu_free(out_buf);
             return -1;
@@ -1211,6 +1215,7 @@ static int qcow_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
     int growable = bs->growable;
     int ret;
 
+    BLKDBG_EVENT(s->hd, BLKDBG_VMSTATE_SAVE);
     bs->growable = 1;
     ret = bdrv_pwrite(bs, qcow_vm_state_offset(s) + pos, buf, size);
     bs->growable = growable;
@@ -1225,6 +1230,7 @@ static int qcow_load_vmstate(BlockDriverState *bs, uint8_t *buf,
     int growable = bs->growable;
     int ret;
 
+    BLKDBG_EVENT(s->hd, BLKDBG_VMSTATE_LOAD);
     bs->growable = 1;
     ret = bdrv_pread(bs, qcow_vm_state_offset(s) + pos, buf, size);
     bs->growable = growable;