[RFC PATCH v3 02/78] block: add fallthrough pseudo-keyword

[Emmanouil Pitsidianakis]

In preparation of raising -Wimplicit-fallthrough to 5, replace all
fall-through comments with the fallthrough attribute pseudo-keyword.

Signed-off-by: Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
---
 block/block-copy.c    |  1 +
 block/file-posix.c    |  1 +
 block/io.c            |  1 +
 block/iscsi.c         |  1 +
 block/qcow2-cluster.c |  5 ++++-
 block/vhdx.c          | 17 +++++++++++++----
 6 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/block/block-copy.c b/block/block-copy.c
index 1c60368d72..b4ceb6a079 100644
--- a/block/block-copy.c
+++ b/block/block-copy.c
@@ -508,6 +508,7 @@ block_copy_do_copy(BlockCopyState *s, int64_t offset, 
int64_t bytes,
         trace_block_copy_copy_range_fail(s, offset, ret);
         *method = COPY_READ_WRITE;
         /* Fall through to read+write with allocated buffer */
+        fallthrough;
 
     case COPY_READ_WRITE_CLUSTER:
     case COPY_READ_WRITE:
diff --git a/block/file-posix.c b/block/file-posix.c
index 50e2b20d5c..31c7719da5 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -1013,6 +1013,7 @@ static int raw_handle_perm_lock(BlockDriverState *bs,
                               bs->filename);
         }
         /* fall through to unlock bytes. */
+        fallthrough;
     case RAW_PL_ABORT:
         raw_apply_lock_bytes(s, s->fd, s->perm, ~s->shared_perm,
                              true, &local_err);
diff --git a/block/io.c b/block/io.c
index e7f9448d5a..cc05457d02 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2034,6 +2034,7 @@ bdrv_co_write_req_finish(BdrvChild *child, int64_t 
offset, int64_t bytes,
         case BDRV_TRACKED_WRITE:
             stat64_max(&bs->wr_highest_offset, offset + bytes);
             /* fall through, to set dirty bits */
+            fallthrough;
         case BDRV_TRACKED_DISCARD:
             bdrv_set_dirty(bs, offset, bytes);
             break;
diff --git a/block/iscsi.c b/block/iscsi.c
index 5640c8b565..2fb7037748 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -1461,6 +1461,7 @@ static void iscsi_readcapacity_sync(IscsiLun *iscsilun, 
Error **errp)
                 break;
             }
             /* Fall through and try READ CAPACITY(10) instead.  */
+            fallthrough;
         case TYPE_ROM:
             task = iscsi_readcapacity10_sync(iscsilun->iscsi, iscsilun->lun, 
0, 0);
             if (task != NULL && task->status == SCSI_STATUS_GOOD) {
diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c
index f4f6cd6ad0..c50143d493 100644
--- a/block/qcow2-cluster.c
+++ b/block/qcow2-cluster.c
@@ -1333,13 +1333,16 @@ static bool cluster_needs_new_alloc(BlockDriverState 
*bs, uint64_t l2_entry)
 {
     switch (qcow2_get_cluster_type(bs, l2_entry)) {
     case QCOW2_CLUSTER_NORMAL:
+        fallthrough;
     case QCOW2_CLUSTER_ZERO_ALLOC:
         if (l2_entry & QCOW_OFLAG_COPIED) {
             return false;
         }
-        /* fallthrough */
+        fallthrough;
     case QCOW2_CLUSTER_UNALLOCATED:
+        fallthrough;
     case QCOW2_CLUSTER_COMPRESSED:
+        fallthrough;
     case QCOW2_CLUSTER_ZERO_PLAIN:
         return true;
     default:
diff --git a/block/vhdx.c b/block/vhdx.c
index a67edcc03e..9000b3fcea 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -1201,10 +1201,14 @@ vhdx_co_readv(BlockDriverState *bs, int64_t sector_num, 
int nb_sectors,
 
             /* check the payload block state */
             switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) {
-            case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */
+            case PAYLOAD_BLOCK_NOT_PRESENT:
+                fallthrough;
             case PAYLOAD_BLOCK_UNDEFINED:
+                fallthrough;
             case PAYLOAD_BLOCK_UNMAPPED:
+                fallthrough;
             case PAYLOAD_BLOCK_UNMAPPED_v095:
+                fallthrough;
             case PAYLOAD_BLOCK_ZERO:
                 /* return zero */
                 qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail);
@@ -1222,6 +1226,7 @@ vhdx_co_readv(BlockDriverState *bs, int64_t sector_num, 
int nb_sectors,
             case PAYLOAD_BLOCK_PARTIALLY_PRESENT:
                 /* we don't yet support difference files, fall through
                  * to error */
+                fallthrough;
             default:
                 ret = -EIO;
                 goto exit;
@@ -1373,10 +1378,13 @@ vhdx_co_writev(BlockDriverState *bs, int64_t 
sector_num, int nb_sectors,
                  * data that is not part of this write, so we must pad
                  * the rest of the buffer to zeroes */
                 use_zero_buffers = true;
-                /* fall through */
-            case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */
+                fallthrough;
+            case PAYLOAD_BLOCK_NOT_PRESENT:
+                fallthrough;
             case PAYLOAD_BLOCK_UNMAPPED:
+                fallthrough;
             case PAYLOAD_BLOCK_UNMAPPED_v095:
+                fallthrough;
             case PAYLOAD_BLOCK_UNDEFINED:
                 bat_prior_offset = sinfo.file_offset;
                 ret = vhdx_allocate_block(bs, s, &sinfo.file_offset,
@@ -1431,7 +1439,7 @@ vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, 
int nb_sectors,
                     }
                 }
 
-                /* fall through */
+                fallthrough;
             case PAYLOAD_BLOCK_FULLY_PRESENT:
                 /* if the file offset address is in the header zone,
                  * there is a problem */
@@ -1457,6 +1465,7 @@ vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, 
int nb_sectors,
             case PAYLOAD_BLOCK_PARTIALLY_PRESENT:
                 /* we don't yet support difference files, fall through
                  * to error */
+                fallthrough;
             default:
                 ret = -EIO;
                 goto exit;
-- 
2.39.2