[PATCH] afs: Mark expected switch fall-throughs

[PATCH] afs: Mark expected switch fall-throughs

[Gustavo A. R. Silva]

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Warning level 2 was used: -Wimplicit-fallthrough=2

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 fs/afs/cmservice.c | 10 ++++++++--
 fs/afs/file.c      |  2 ++
 fs/afs/fsclient.c  | 41 +++++++++++++++++++++++++++--------------
 fs/afs/rxrpc.c     |  1 +
 fs/afs/vlclient.c  | 29 ++++++++++++++++-------------
 5 files changed, 54 insertions(+), 29 deletions(-)

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 9e51d6f..c06fcda 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -179,7 +179,8 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* extract the FID array and its count in two steps */
+		/* Fall through and extract the FID array and its count
+		 * in two steps. */
 	case 1:
 		_debug("extract FID count");
 		ret = afs_extract_data(call, &call->tmp, 4, true);
@@ -198,6 +199,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
+		/* Fall through */
 	case 2:
 		_debug("extract FID array");
 		ret = afs_extract_data(call, call->buffer,
@@ -224,7 +226,8 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* extract the callback array and its count in two steps */
+		/* Fall through and extract the callback array and its count
+		 * in two steps. */
 	case 3:
 		_debug("extract CB count");
 		ret = afs_extract_data(call, &call->tmp, 4, true);
@@ -238,6 +241,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
+		/* Fall through */
 	case 4:
 		_debug("extract CB array");
 		ret = afs_extract_data(call, call->buffer,
@@ -336,6 +340,7 @@ static int afs_deliver_cb_init_call_back_state3(struct afs_call *call)
 			return -ENOMEM;
 		call->unmarshall++;
 
+		/* Fall through */
 	case 1:
 		_debug("extract UUID");
 		ret = afs_extract_data(call, call->buffer,
@@ -459,6 +464,7 @@ static int afs_deliver_cb_probe_uuid(struct afs_call *call)
 			return -ENOMEM;
 		call->unmarshall++;
 
+		/* Fall through */
 	case 1:
 		_debug("extract UUID");
 		ret = afs_extract_data(call, call->buffer,
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 7d4f261..4a853ba 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -299,6 +299,8 @@ int afs_page_filler(void *data, struct page *page)
 		/* page will not be cached */
 	case -ENOBUFS:
 		_debug("cache said ENOBUFS");
+
+		/* fall through */
 	default:
 	go_on:
 		req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 50929cb..34fa791 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -485,9 +485,9 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 			goto no_msw;
 		}
 
-		/* extract the upper part of the returned data length of an
-		 * FSFETCHDATA64 op (which should always be 0 using this
-		 * client) */
+		/* Fall through and extract the upper part of the returned data
+		 * length of an FSFETCHDATA64 op (which should always be 0 using
+		 * this client) */
 	case 1:
 		_debug("extract data length (MSW)");
 		ret = afs_extract_data(call, &call->tmp, 4, true);
@@ -499,6 +499,7 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
+		/* Fall through */
 	no_msw:
 		/* extract the returned data length */
 	case 2:
@@ -527,7 +528,7 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 		ASSERTCMP(call->count, <=, PAGE_SIZE);
 		req->remain -= size;
 
-		/* extract the returned data */
+		/* Fall through and extract the returned data */
 	case 3:
 		_debug("extract data %llu/%llu %zu/%u",
 		       req->remain, req->actual_len, call->offset, call->count);
@@ -572,7 +573,7 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall = 5;
 
-		/* extract the metadata */
+		/* Fall through and extract the metadata */
 	case 5:
 		ret = afs_extract_data(call, call->buffer,
 				       (21 + 3 + 6) * 4, false);
@@ -1590,7 +1591,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* extract the returned status record */
+		/* Fall through and extract the returned status record */
 	case 1:
 		_debug("extract status");
 		ret = afs_extract_data(call, call->buffer,
@@ -1603,7 +1604,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* extract the volume name length */
+		/* Fall through extract the volume name length */
 	case 2:
 		ret = afs_extract_data(call, &call->tmp, 4, true);
 		if (ret < 0)
@@ -1616,7 +1617,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* extract the volume name */
+		/* Fall through and extract the volume name */
 	case 3:
 		_debug("extract volname");
 		if (call->count > 0) {
@@ -1640,6 +1641,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		}
 		call->count = 4 - (call->count & 3);
 
+		/* Fall through */
 	case 4:
 		ret = afs_extract_data(call, call->buffer,
 				       call->count, true);
@@ -1648,6 +1650,8 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 
 		call->offset = 0;
 		call->unmarshall++;
+
+		/* Fall through */
 	no_volname_padding:
 
 		/* extract the offline message length */
@@ -1663,7 +1667,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* extract the offline message */
+		/* Fall through and extract the offline message */
 	case 6:
 		_debug("extract offline");
 		if (call->count > 0) {
@@ -1687,6 +1691,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		}
 		call->count = 4 - (call->count & 3);
 
+		/* Fall through */
 	case 7:
 		ret = afs_extract_data(call, call->buffer,
 				       call->count, true);
@@ -1695,6 +1700,8 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 
 		call->offset = 0;
 		call->unmarshall++;
+
+		/* Fall through */
 	no_offline_padding:
 
 		/* extract the message of the day length */
@@ -1710,7 +1717,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* extract the message of the day */
+		/* Fall through and extract the message of the day */
 	case 9:
 		_debug("extract motd");
 		if (call->count > 0) {
@@ -1730,6 +1737,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		/* extract the message of the day padding */
 		call->count = (4 - (call->count & 3)) & 3;
 
+		/* Fall through */
 	case 10:
 		ret = afs_extract_data(call, call->buffer,
 				       call->count, false);
@@ -2012,7 +2020,7 @@ static int afs_deliver_fs_get_capabilities(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* Extract the capabilities word count */
+		/* Fall through and extract the capabilities word count */
 	case 1:
 		ret = afs_extract_data(call, &call->tmp,
 				       1 * sizeof(__be32),
@@ -2027,7 +2035,7 @@ static int afs_deliver_fs_get_capabilities(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* Extract capabilities words */
+		/* Fall through and extract capabilities words */
 	case 2:
 		count = min(call->count, 16U);
 		ret = afs_extract_data(call, call->buffer,
@@ -2196,7 +2204,8 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* Extract the file status count and array in two steps */
+		/* Fall through and extract the file status count and array
+		 * in two steps. */
 	case 1:
 		_debug("extract status count");
 		ret = afs_extract_data(call, &call->tmp, 4, true);
@@ -2213,6 +2222,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 	more_counts:
 		call->offset = 0;
 
+		/* Fall through */
 	case 2:
 		_debug("extract status array %u", call->count);
 		ret = afs_extract_data(call, call->buffer, 21 * 4, true);
@@ -2234,7 +2244,8 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		call->unmarshall++;
 		call->offset = 0;
 
-		/* Extract the callback count and array in two steps */
+		/* Fall through and extract the callback count and array in
+		 * two steps. */
 	case 3:
 		_debug("extract CB count");
 		ret = afs_extract_data(call, &call->tmp, 4, true);
@@ -2250,6 +2261,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 	more_cbs:
 		call->offset = 0;
 
+		/* Fall through */
 	case 4:
 		_debug("extract CB array");
 		ret = afs_extract_data(call, call->buffer, 3 * 4, true);
@@ -2272,6 +2284,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
+		/* Fall through */
 	case 5:
 		ret = afs_extract_data(call, call->buffer, 6 * 4, false);
 		if (ret < 0)
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 183cc54..d0f915a 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -842,6 +842,7 @@ void afs_send_empty_reply(struct afs_call *call)
 		_debug("oom");
 		rxrpc_kernel_abort_call(net->socket, call->rxcall,
 					RX_USER_ABORT, -ENOMEM, "KOO");
+		/* Fall through */
 	default:
 		_leave(" [error]");
 		return;
diff --git a/fs/afs/vlclient.c b/fs/afs/vlclient.c
index c3b7408..e94735c 100644
--- a/fs/afs/vlclient.c
+++ b/fs/afs/vlclient.c
@@ -195,7 +195,9 @@ static int afs_deliver_vl_get_addrs_u(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* Extract the returned uuid, uniquifier, nentries and blkaddrs size */
+
+		/* Fall through and extract the returned uuid, uniquifier,
+		 * nentries and blkaddrs size. */
 	case 1:
 		ret = afs_extract_data(call, call->buffer,
 				       sizeof(struct afs_uuid__xdr) + 3 * sizeof(__be32),
@@ -219,7 +221,7 @@ static int afs_deliver_vl_get_addrs_u(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* Extract entries */
+		/* Fall through and extract entries */
 	case 2:
 		count = min(call->count, 4U);
 		ret = afs_extract_data(call, call->buffer,
@@ -326,7 +328,7 @@ static int afs_deliver_vl_get_capabilities(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* Extract the capabilities word count */
+		/* Fall through and extract the capabilities word count */
 	case 1:
 		ret = afs_extract_data(call, &call->tmp,
 				       1 * sizeof(__be32),
@@ -341,7 +343,7 @@ static int afs_deliver_vl_get_capabilities(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* Extract capabilities words */
+		/* Fall through and extract capabilities words */
 	case 2:
 		count = min(call->count, 16U);
 		ret = afs_extract_data(call, call->buffer,
@@ -434,9 +436,9 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall = 1;
 
-		/* Extract the returned uuid, uniquifier, fsEndpoints count and
-		 * either the first fsEndpoint type or the volEndpoints
-		 * count if there are no fsEndpoints. */
+		/* Fall through and extract the returned uuid, uniquifier,
+		 * fsEndpoints count and either the first fsEndpoint type
+		 * or the volEndpoints count if there are no fsEndpoints. */
 	case 1:
 		ret = afs_extract_data(call, call->buffer,
 				       sizeof(uuid_t) +
@@ -465,7 +467,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 
 		call->unmarshall = 2;
 
-		/* Extract fsEndpoints[] entries */
+		/* Fall through and extract fsEndpoints[] entries */
 	case 2:
 		switch (call->count2) {
 		case YFS_ENDPOINT_IPV4:
@@ -522,9 +524,10 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 
 		call->unmarshall = 3;
 
-		/* Extract the type of volEndpoints[0].  Normally we would
-		 * extract the type of the next endpoint when we extract the
-		 * data of the current one, but this is the first...
+		/* Fall through and extract the type of volEndpoints[0].
+		 * Normally we would extract the type of the next endpoint
+		 * when we extract the data of the current one, but this is
+		 * the first...
 		 */
 	case 3:
 		ret = afs_extract_data(call, call->buffer, sizeof(__be32), true);
@@ -536,7 +539,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall = 4;
 
-		/* Extract volEndpoints[] entries */
+		/* Fall through and extract volEndpoints[] entries */
 	case 4:
 		switch (call->count2) {
 		case YFS_ENDPOINT_IPV4:
@@ -584,7 +587,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 	end:
 		call->unmarshall = 5;
 
-		/* Done */
+		/* Fall through - Done */
 	case 5:
 		ret = afs_extract_data(call, call->buffer, 0, false);
 		if (ret < 0)
-- 
2.7.4

Re: [PATCH] afs: Mark expected switch fall-throughs

[David Howells]

Gustavo A. R. Silva <gustavo@embeddedor.com> wrote:

> +		/* Fall through */
>  	no_msw:
>  		/* extract the returned data length */
>  	case 2:

That would appear to be added in the wrong place.  The fall-through is after
the no_msw label.

> +
> +		/* Fall through */
>  	no_volname_padding:

Ditto - and several other dittos too.

> -		/* Done */
> +		/* Fall through - Done */

Yuck.

> +
> +		/* fall through */

Capital 'F' for consistency please.

Whilst I understand the argument for explicitly marking the fall-throughs to
catch missing breaks, it's a bit irritating at times.  Can we have an
additional annotation that tells the compiler that every case in a switch
statement is going to fall through (so no break before case) except the last?
That would be more useful in this case.

David

[PATCH] afs: Mark expected switch fall-throughs

[Gustavo A. R. Silva]

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Notice that in many cases I placed a /* Fall through */ comment
at the bottom of the case, which what GCC is expecting to find.

In other cases I had to tweak a bit the format of the comments.

This patch suppresses 39 missing-break-in-switch false positives.

Addresses-Coverity-ID: 115042 ("Missing break in switch")
Addresses-Coverity-ID: 115043 ("Missing break in switch")
Addresses-Coverity-ID: 115045 ("Missing break in switch")
Addresses-Coverity-ID: 1357430 ("Missing break in switch")
Addresses-Coverity-ID: 115047 ("Missing break in switch")
Addresses-Coverity-ID: 115050 ("Missing break in switch")
Addresses-Coverity-ID: 115051 ("Missing break in switch")
Addresses-Coverity-ID: 1467806 ("Missing break in switch")
Addresses-Coverity-ID: 1467807 ("Missing break in switch")
Addresses-Coverity-ID: 1467811 ("Missing break in switch")
Addresses-Coverity-ID: 115041 ("Missing break in switch")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 fs/afs/cmservice.c |  6 ++++++
 fs/afs/file.c      |  2 ++
 fs/afs/fsclient.c  | 34 ++++++++++++++++++++++++----------
 fs/afs/rxrpc.c     |  1 +
 fs/afs/vlclient.c  | 18 +++++++++++-------
 5 files changed, 44 insertions(+), 17 deletions(-)

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 9e51d6f..ecf7aee 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -180,6 +180,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		call->unmarshall++;
 
 		/* extract the FID array and its count in two steps */
+		/* fall through */
 	case 1:
 		_debug("extract FID count");
 		ret = afs_extract_data(call, &call->tmp, 4, true);
@@ -198,6 +199,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
+		/* Fall through */
 	case 2:
 		_debug("extract FID array");
 		ret = afs_extract_data(call, call->buffer,
@@ -225,6 +227,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		call->unmarshall++;
 
 		/* extract the callback array and its count in two steps */
+		/* fall through */
 	case 3:
 		_debug("extract CB count");
 		ret = afs_extract_data(call, &call->tmp, 4, true);
@@ -238,6 +241,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
+		/* Fall through */
 	case 4:
 		_debug("extract CB array");
 		ret = afs_extract_data(call, call->buffer,
@@ -336,6 +340,7 @@ static int afs_deliver_cb_init_call_back_state3(struct afs_call *call)
 			return -ENOMEM;
 		call->unmarshall++;
 
+		/* Fall through */
 	case 1:
 		_debug("extract UUID");
 		ret = afs_extract_data(call, call->buffer,
@@ -459,6 +464,7 @@ static int afs_deliver_cb_probe_uuid(struct afs_call *call)
 			return -ENOMEM;
 		call->unmarshall++;
 
+		/* Fall through */
 	case 1:
 		_debug("extract UUID");
 		ret = afs_extract_data(call, call->buffer,
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 7d4f261..4a853ba 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -299,6 +299,8 @@ int afs_page_filler(void *data, struct page *page)
 		/* page will not be cached */
 	case -ENOBUFS:
 		_debug("cache said ENOBUFS");
+
+		/* fall through */
 	default:
 	go_on:
 		req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index 50929cb..2c8abf3 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -485,9 +485,10 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 			goto no_msw;
 		}
 
-		/* extract the upper part of the returned data length of an
+		/* Extract the upper part of the returned data length of an
 		 * FSFETCHDATA64 op (which should always be 0 using this
 		 * client) */
+		/* Fall through */
 	case 1:
 		_debug("extract data length (MSW)");
 		ret = afs_extract_data(call, &call->tmp, 4, true);
@@ -499,6 +500,7 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
+		/* Fall through */
 	no_msw:
 		/* extract the returned data length */
 	case 2:
@@ -527,7 +529,7 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 		ASSERTCMP(call->count, <=, PAGE_SIZE);
 		req->remain -= size;
 
-		/* extract the returned data */
+		/* Fall through - and extract the returned data */
 	case 3:
 		_debug("extract data %llu/%llu %zu/%u",
 		       req->remain, req->actual_len, call->offset, call->count);
@@ -572,7 +574,7 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall = 5;
 
-		/* extract the metadata */
+		/* Fall through - and extract the metadata */
 	case 5:
 		ret = afs_extract_data(call, call->buffer,
 				       (21 + 3 + 6) * 4, false);
@@ -1590,7 +1592,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* extract the returned status record */
+		/* Fall through - and extract the returned status record */
 	case 1:
 		_debug("extract status");
 		ret = afs_extract_data(call, call->buffer,
@@ -1603,7 +1605,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* extract the volume name length */
+		/* Fall through - and extract the volume name length */
 	case 2:
 		ret = afs_extract_data(call, &call->tmp, 4, true);
 		if (ret < 0)
@@ -1616,7 +1618,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* extract the volume name */
+		/* Fall through - and extract the volume name */
 	case 3:
 		_debug("extract volname");
 		if (call->count > 0) {
@@ -1640,6 +1642,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		}
 		call->count = 4 - (call->count & 3);
 
+		/* Fall through */
 	case 4:
 		ret = afs_extract_data(call, call->buffer,
 				       call->count, true);
@@ -1648,6 +1651,8 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 
 		call->offset = 0;
 		call->unmarshall++;
+
+		/* Fall through */
 	no_volname_padding:
 
 		/* extract the offline message length */
@@ -1663,7 +1668,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* extract the offline message */
+		/* Fall through - and extract the offline message */
 	case 6:
 		_debug("extract offline");
 		if (call->count > 0) {
@@ -1687,6 +1692,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		}
 		call->count = 4 - (call->count & 3);
 
+		/* Fall through */
 	case 7:
 		ret = afs_extract_data(call, call->buffer,
 				       call->count, true);
@@ -1695,6 +1701,8 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 
 		call->offset = 0;
 		call->unmarshall++;
+
+		/* Fall through */
 	no_offline_padding:
 
 		/* extract the message of the day length */
@@ -1710,7 +1718,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* extract the message of the day */
+		/* Fall through - and extract the message of the day */
 	case 9:
 		_debug("extract motd");
 		if (call->count > 0) {
@@ -1730,6 +1738,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		/* extract the message of the day padding */
 		call->count = (4 - (call->count & 3)) & 3;
 
+		/* Fall through */
 	case 10:
 		ret = afs_extract_data(call, call->buffer,
 				       call->count, false);
@@ -2012,7 +2021,7 @@ static int afs_deliver_fs_get_capabilities(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* Extract the capabilities word count */
+		/* Fall through - and extract the capabilities word count */
 	case 1:
 		ret = afs_extract_data(call, &call->tmp,
 				       1 * sizeof(__be32),
@@ -2027,7 +2036,7 @@ static int afs_deliver_fs_get_capabilities(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* Extract capabilities words */
+		/* Fall through - and extract capabilities words */
 	case 2:
 		count = min(call->count, 16U);
 		ret = afs_extract_data(call, call->buffer,
@@ -2197,6 +2206,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		call->unmarshall++;
 
 		/* Extract the file status count and array in two steps */
+		/* Fall through */
 	case 1:
 		_debug("extract status count");
 		ret = afs_extract_data(call, &call->tmp, 4, true);
@@ -2213,6 +2223,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 	more_counts:
 		call->offset = 0;
 
+		/* Fall through */
 	case 2:
 		_debug("extract status array %u", call->count);
 		ret = afs_extract_data(call, call->buffer, 21 * 4, true);
@@ -2235,6 +2246,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		call->offset = 0;
 
 		/* Extract the callback count and array in two steps */
+		/* Fall through */
 	case 3:
 		_debug("extract CB count");
 		ret = afs_extract_data(call, &call->tmp, 4, true);
@@ -2250,6 +2262,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 	more_cbs:
 		call->offset = 0;
 
+		/* Fall through */
 	case 4:
 		_debug("extract CB array");
 		ret = afs_extract_data(call, call->buffer, 3 * 4, true);
@@ -2272,6 +2285,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
+		/* Fall through */
 	case 5:
 		ret = afs_extract_data(call, call->buffer, 6 * 4, false);
 		if (ret < 0)
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index 77a8379..59da27e 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -840,6 +840,7 @@ void afs_send_empty_reply(struct afs_call *call)
 		_debug("oom");
 		rxrpc_kernel_abort_call(net->socket, call->rxcall,
 					RX_USER_ABORT, -ENOMEM, "KOO");
+		/* Fall through */
 	default:
 		_leave(" [error]");
 		return;
diff --git a/fs/afs/vlclient.c b/fs/afs/vlclient.c
index c3b7408..ec15c24 100644
--- a/fs/afs/vlclient.c
+++ b/fs/afs/vlclient.c
@@ -195,7 +195,9 @@ static int afs_deliver_vl_get_addrs_u(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* Extract the returned uuid, uniquifier, nentries and blkaddrs size */
+		/* Extract the returned uuid, uniquifier, nentries and
+		 * blkaddrs size */
+		/* Fall through */
 	case 1:
 		ret = afs_extract_data(call, call->buffer,
 				       sizeof(struct afs_uuid__xdr) + 3 * sizeof(__be32),
@@ -219,7 +221,7 @@ static int afs_deliver_vl_get_addrs_u(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* Extract entries */
+		/* Fall through - and extract entries */
 	case 2:
 		count = min(call->count, 4U);
 		ret = afs_extract_data(call, call->buffer,
@@ -326,7 +328,7 @@ static int afs_deliver_vl_get_capabilities(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* Extract the capabilities word count */
+		/* Fall through - and extract the capabilities word count */
 	case 1:
 		ret = afs_extract_data(call, &call->tmp,
 				       1 * sizeof(__be32),
@@ -341,7 +343,7 @@ static int afs_deliver_vl_get_capabilities(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall++;
 
-		/* Extract capabilities words */
+		/* Fall through - and extract capabilities words */
 	case 2:
 		count = min(call->count, 16U);
 		ret = afs_extract_data(call, call->buffer,
@@ -437,6 +439,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		/* Extract the returned uuid, uniquifier, fsEndpoints count and
 		 * either the first fsEndpoint type or the volEndpoints
 		 * count if there are no fsEndpoints. */
+		/* Fall through */
 	case 1:
 		ret = afs_extract_data(call, call->buffer,
 				       sizeof(uuid_t) +
@@ -465,7 +468,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 
 		call->unmarshall = 2;
 
-		/* Extract fsEndpoints[] entries */
+		/* Fall through - and extract fsEndpoints[] entries */
 	case 2:
 		switch (call->count2) {
 		case YFS_ENDPOINT_IPV4:
@@ -526,6 +529,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		 * extract the type of the next endpoint when we extract the
 		 * data of the current one, but this is the first...
 		 */
+		/* Fall through */
 	case 3:
 		ret = afs_extract_data(call, call->buffer, sizeof(__be32), true);
 		if (ret < 0)
@@ -536,7 +540,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		call->offset = 0;
 		call->unmarshall = 4;
 
-		/* Extract volEndpoints[] entries */
+		/* Fall through - and extract volEndpoints[] entries */
 	case 4:
 		switch (call->count2) {
 		case YFS_ENDPOINT_IPV4:
@@ -584,7 +588,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 	end:
 		call->unmarshall = 5;
 
-		/* Done */
+		/* Fall through - Done */
 	case 5:
 		ret = afs_extract_data(call, call->buffer, 0, false);
 		if (ret < 0)
-- 
2.7.4

[PATCH] afs: Mark expected switch fall-throughs

[Gustavo A. R. Silva]

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Notice that in many cases I placed a /* Fall through */ comment
at the bottom of the case, which what GCC is expecting to find.

In other cases I had to tweak a bit the format of the comments.

This patch suppresses ALL missing-break-in-switch false positives
in fs/afs

Addresses-Coverity-ID: 115042 ("Missing break in switch")
Addresses-Coverity-ID: 115043 ("Missing break in switch")
Addresses-Coverity-ID: 115045 ("Missing break in switch")
Addresses-Coverity-ID: 1357430 ("Missing break in switch")
Addresses-Coverity-ID: 115047 ("Missing break in switch")
Addresses-Coverity-ID: 115050 ("Missing break in switch")
Addresses-Coverity-ID: 115051 ("Missing break in switch")
Addresses-Coverity-ID: 1467806 ("Missing break in switch")
Addresses-Coverity-ID: 1467807 ("Missing break in switch")
Addresses-Coverity-ID: 1467811 ("Missing break in switch")
Addresses-Coverity-ID: 115041 ("Missing break in switch")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 fs/afs/cmservice.c |  8 ++++++++
 fs/afs/file.c      |  2 ++
 fs/afs/flock.c     |  1 +
 fs/afs/fsclient.c  | 31 +++++++++++++++++++------------
 fs/afs/misc.c      |  9 +++++++++
 fs/afs/rxrpc.c     |  1 +
 fs/afs/vlclient.c  | 18 +++++++++++-------
 fs/afs/yfsclient.c | 30 ++++++++++++++++++++----------
 8 files changed, 71 insertions(+), 29 deletions(-)

diff --git a/fs/afs/cmservice.c b/fs/afs/cmservice.c
index 8ee5972893ed..40e09bf547e3 100644
--- a/fs/afs/cmservice.c
+++ b/fs/afs/cmservice.c
@@ -285,6 +285,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		call->unmarshall++;
 
 		/* extract the FID array and its count in two steps */
+		/* fall through */
 	case 1:
 		_debug("extract FID count");
 		ret = afs_extract_data(call, true);
@@ -304,6 +305,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		afs_extract_to_buf(call, call->count * 3 * 4);
 		call->unmarshall++;
 
+		/* Fall through */
 	case 2:
 		_debug("extract FID array");
 		ret = afs_extract_data(call, true);
@@ -329,6 +331,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		call->unmarshall++;
 
 		/* extract the callback array and its count in two steps */
+		/* fall through */
 	case 3:
 		_debug("extract CB count");
 		ret = afs_extract_data(call, true);
@@ -344,6 +347,7 @@ static int afs_deliver_cb_callback(struct afs_call *call)
 		iov_iter_discard(&call->iter, READ, call->count2 * 3 * 4);
 		call->unmarshall++;
 
+		/* Fall through */
 	case 4:
 		_debug("extract discard %zu/%u",
 		       iov_iter_count(&call->iter), call->count2 * 3 * 4);
@@ -422,6 +426,7 @@ static int afs_deliver_cb_init_call_back_state3(struct afs_call *call)
 		afs_extract_to_buf(call, 11 * sizeof(__be32));
 		call->unmarshall++;
 
+		/* Fall through */
 	case 1:
 		_debug("extract UUID");
 		ret = afs_extract_data(call, false);
@@ -537,6 +542,7 @@ static int afs_deliver_cb_probe_uuid(struct afs_call *call)
 		afs_extract_to_buf(call, 11 * sizeof(__be32));
 		call->unmarshall++;
 
+		/* Fall through */
 	case 1:
 		_debug("extract UUID");
 		ret = afs_extract_data(call, false);
@@ -673,6 +679,7 @@ static int afs_deliver_yfs_cb_callback(struct afs_call *call)
 		call->unmarshall++;
 
 		/* extract the FID array and its count in two steps */
+		/* Fall through */
 	case 1:
 		_debug("extract FID count");
 		ret = afs_extract_data(call, true);
@@ -692,6 +699,7 @@ static int afs_deliver_yfs_cb_callback(struct afs_call *call)
 		afs_extract_to_buf(call, size);
 		call->unmarshall++;
 
+		/* Fall through */
 	case 2:
 		_debug("extract FID array");
 		ret = afs_extract_data(call, false);
diff --git a/fs/afs/file.c b/fs/afs/file.c
index 323ae9912203..e8d6619890a9 100644
--- a/fs/afs/file.c
+++ b/fs/afs/file.c
@@ -300,6 +300,8 @@ int afs_page_filler(void *data, struct page *page)
 		/* page will not be cached */
 	case -ENOBUFS:
 		_debug("cache said ENOBUFS");
+
+		/* fall through */
 	default:
 	go_on:
 		req = kzalloc(sizeof(struct afs_read) + sizeof(struct page *),
diff --git a/fs/afs/flock.c b/fs/afs/flock.c
index 0568fd986821..65e2209fb487 100644
--- a/fs/afs/flock.c
+++ b/fs/afs/flock.c
@@ -303,6 +303,7 @@ void afs_lock_work(struct work_struct *work)
 			return;
 		}
 
+		/* Fall through */
 	default:
 		/* Looks like a lock request was withdrawn. */
 		spin_unlock(&vnode->lock);
diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c
index ca08c83168f5..06277408477b 100644
--- a/fs/afs/fsclient.c
+++ b/fs/afs/fsclient.c
@@ -498,7 +498,7 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 			afs_extract_to_tmp(call);
 		}
 
-		/* extract the returned data length */
+		/* Fall through - and extract the returned data length */
 	case 1:
 		_debug("extract data length");
 		ret = afs_extract_data(call, true);
@@ -525,7 +525,7 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 		iov_iter_bvec(&call->iter, READ, call->bvec, 1, size);
 		ASSERTCMP(size, <=, PAGE_SIZE);
 
-		/* extract the returned data */
+		/* Fall through - and extract the returned data */
 	case 2:
 		_debug("extract data %zu/%llu",
 		       iov_iter_count(&call->iter), req->remain);
@@ -552,6 +552,8 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 		/* Discard any excess data the server gave us */
 		iov_iter_discard(&call->iter, READ, req->actual_len - req->len);
 		call->unmarshall = 3;
+
+		/* Fall through */
 	case 3:
 		_debug("extract discard %zu/%llu",
 		       iov_iter_count(&call->iter), req->actual_len - req->len);
@@ -564,7 +566,7 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call)
 		call->unmarshall = 4;
 		afs_extract_to_buf(call, (21 + 3 + 6) * 4);
 
-		/* extract the metadata */
+		/* Fall through - and extract the metadata */
 	case 4:
 		ret = afs_extract_data(call, false);
 		if (ret < 0)
@@ -1634,7 +1636,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->unmarshall++;
 		afs_extract_to_buf(call, 12 * 4);
 
-		/* extract the returned status record */
+		/* Fall through - and extract the returned status record */
 	case 1:
 		_debug("extract status");
 		ret = afs_extract_data(call, true);
@@ -1646,7 +1648,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->unmarshall++;
 		afs_extract_to_tmp(call);
 
-		/* extract the volume name length */
+		/* Fall through - and extract the volume name length */
 	case 2:
 		ret = afs_extract_data(call, true);
 		if (ret < 0)
@@ -1661,7 +1663,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		afs_extract_begin(call, call->reply[2], size);
 		call->unmarshall++;
 
-		/* extract the volume name */
+		/* Fall through - and extract the volume name */
 	case 3:
 		_debug("extract volname");
 		ret = afs_extract_data(call, true);
@@ -1674,7 +1676,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
-		/* extract the offline message length */
+		/* Fall through - and extract the offline message length */
 	case 4:
 		ret = afs_extract_data(call, true);
 		if (ret < 0)
@@ -1689,7 +1691,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		afs_extract_begin(call, call->reply[2], size);
 		call->unmarshall++;
 
-		/* extract the offline message */
+		/* Fall through - and extract the offline message */
 	case 5:
 		_debug("extract offline");
 		ret = afs_extract_data(call, true);
@@ -1703,7 +1705,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
-		/* extract the message of the day length */
+		/* Fall through - and extract the message of the day length */
 	case 6:
 		ret = afs_extract_data(call, true);
 		if (ret < 0)
@@ -1718,7 +1720,7 @@ static int afs_deliver_fs_get_volume_status(struct afs_call *call)
 		afs_extract_begin(call, call->reply[2], size);
 		call->unmarshall++;
 
-		/* extract the message of the day */
+		/* Fall through - and extract the message of the day */
 	case 7:
 		_debug("extract motd");
 		ret = afs_extract_data(call, false);
@@ -2016,7 +2018,7 @@ static int afs_deliver_fs_get_capabilities(struct afs_call *call)
 		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
-		/* Extract the capabilities word count */
+		/* Fall through - and extract the capabilities word count */
 	case 1:
 		ret = afs_extract_data(call, true);
 		if (ret < 0)
@@ -2029,7 +2031,7 @@ static int afs_deliver_fs_get_capabilities(struct afs_call *call)
 		iov_iter_discard(&call->iter, READ, count * sizeof(__be32));
 		call->unmarshall++;
 
-		/* Extract capabilities words */
+		/* Fall through - and extract capabilities words */
 	case 2:
 		ret = afs_extract_data(call, false);
 		if (ret < 0)
@@ -2206,6 +2208,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		call->unmarshall++;
 
 		/* Extract the file status count and array in two steps */
+		/* Fall through */
 	case 1:
 		_debug("extract status count");
 		ret = afs_extract_data(call, true);
@@ -2223,6 +2226,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 	more_counts:
 		afs_extract_to_buf(call, 21 * sizeof(__be32));
 
+		/* Fall through */
 	case 2:
 		_debug("extract status array %u", call->count);
 		ret = afs_extract_data(call, true);
@@ -2246,6 +2250,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		afs_extract_to_tmp(call);
 
 		/* Extract the callback count and array in two steps */
+		/* Fall through */
 	case 3:
 		_debug("extract CB count");
 		ret = afs_extract_data(call, true);
@@ -2262,6 +2267,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 	more_cbs:
 		afs_extract_to_buf(call, 3 * sizeof(__be32));
 
+		/* Fall through */
 	case 4:
 		_debug("extract CB array");
 		ret = afs_extract_data(call, true);
@@ -2284,6 +2290,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		afs_extract_to_buf(call, 6 * sizeof(__be32));
 		call->unmarshall++;
 
+		/* Fall through */
 	case 5:
 		ret = afs_extract_data(call, false);
 		if (ret < 0)
diff --git a/fs/afs/misc.c b/fs/afs/misc.c
index bbb1fd51b019..7f2af061ea06 100644
--- a/fs/afs/misc.c
+++ b/fs/afs/misc.c
@@ -131,33 +131,42 @@ void afs_prioritise_error(struct afs_error *e, int error, u32 abort_code)
 		if (e->error == -ETIMEDOUT ||
 		    e->error == -ETIME)
 			return;
+		/* Fall through */
 	case -ETIMEDOUT:
 	case -ETIME:
 		if (e->error == -ENOMEM ||
 		    e->error == -ENONET)
 			return;
+		/* Fall through */
 	case -ENOMEM:
 	case -ENONET:
 		if (e->error == -ERFKILL)
 			return;
+		/* Fall through */
 	case -ERFKILL:
 		if (e->error == -EADDRNOTAVAIL)
 			return;
+		/* Fall through */
 	case -EADDRNOTAVAIL:
 		if (e->error == -ENETUNREACH)
 			return;
+		/* Fall through */
 	case -ENETUNREACH:
 		if (e->error == -EHOSTUNREACH)
 			return;
+		/* Fall through */
 	case -EHOSTUNREACH:
 		if (e->error == -EHOSTDOWN)
 			return;
+		/* Fall through */
 	case -EHOSTDOWN:
 		if (e->error == -ECONNREFUSED)
 			return;
+		/* Fall through */
 	case -ECONNREFUSED:
 		if (e->error == -ECONNRESET)
 			return;
+		/* Fall through */
 	case -ECONNRESET: /* Responded, but call expired. */
 		if (e->responded)
 			return;
diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c
index a7b44863d502..cb55e438ce7b 100644
--- a/fs/afs/rxrpc.c
+++ b/fs/afs/rxrpc.c
@@ -878,6 +878,7 @@ void afs_send_empty_reply(struct afs_call *call)
 		_debug("oom");
 		rxrpc_kernel_abort_call(net->socket, call->rxcall,
 					RX_USER_ABORT, -ENOMEM, "KOO");
+		/* Fall through */
 	default:
 		_leave(" [error]");
 		return;
diff --git a/fs/afs/vlclient.c b/fs/afs/vlclient.c
index c3d9e5a5f67e..b0175b3ef0e8 100644
--- a/fs/afs/vlclient.c
+++ b/fs/afs/vlclient.c
@@ -195,7 +195,9 @@ static int afs_deliver_vl_get_addrs_u(struct afs_call *call)
 				   sizeof(struct afs_uuid__xdr) + 3 * sizeof(__be32));
 		call->unmarshall++;
 
-		/* Extract the returned uuid, uniquifier, nentries and blkaddrs size */
+		/* Extract the returned uuid, uniquifier, nentries and
+		 * blkaddrs size */
+		/* Fall through */
 	case 1:
 		ret = afs_extract_data(call, true);
 		if (ret < 0)
@@ -220,7 +222,7 @@ static int afs_deliver_vl_get_addrs_u(struct afs_call *call)
 		count = min(call->count, 4U);
 		afs_extract_to_buf(call, count * sizeof(__be32));
 
-		/* Extract entries */
+		/* Fall through - and extract entries */
 	case 2:
 		ret = afs_extract_data(call, call->count > 4);
 		if (ret < 0)
@@ -323,7 +325,7 @@ static int afs_deliver_vl_get_capabilities(struct afs_call *call)
 		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
-		/* Extract the capabilities word count */
+		/* Fall through - and extract the capabilities word count */
 	case 1:
 		ret = afs_extract_data(call, true);
 		if (ret < 0)
@@ -336,7 +338,7 @@ static int afs_deliver_vl_get_capabilities(struct afs_call *call)
 		call->unmarshall++;
 		afs_extract_discard(call, count * sizeof(__be32));
 
-		/* Extract capabilities words */
+		/* Fall through - and extract capabilities words */
 	case 2:
 		ret = afs_extract_data(call, false);
 		if (ret < 0)
@@ -436,6 +438,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		/* Extract the returned uuid, uniquifier, fsEndpoints count and
 		 * either the first fsEndpoint type or the volEndpoints
 		 * count if there are no fsEndpoints. */
+		/* Fall through */
 	case 1:
 		ret = afs_extract_data(call, true);
 		if (ret < 0)
@@ -476,7 +479,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		afs_extract_to_buf(call, size);
 		call->unmarshall = 2;
 
-		/* Extract fsEndpoints[] entries */
+		/* Fall through - and extract fsEndpoints[] entries */
 	case 2:
 		ret = afs_extract_data(call, true);
 		if (ret < 0)
@@ -529,6 +532,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		 * extract the type of the next endpoint when we extract the
 		 * data of the current one, but this is the first...
 		 */
+		/* Fall through */
 	case 3:
 		ret = afs_extract_data(call, true);
 		if (ret < 0)
@@ -555,7 +559,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		afs_extract_to_buf(call, size);
 		call->unmarshall = 4;
 
-		/* Extract volEndpoints[] entries */
+		/* Fall through - and extract volEndpoints[] entries */
 	case 4:
 		ret = afs_extract_data(call, true);
 		if (ret < 0)
@@ -591,7 +595,7 @@ static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
 		afs_extract_discard(call, 0);
 		call->unmarshall = 5;
 
-		/* Done */
+		/* Fall through - Done */
 	case 5:
 		ret = afs_extract_data(call, false);
 		if (ret < 0)
diff --git a/fs/afs/yfsclient.c b/fs/afs/yfsclient.c
index 12658c1363ae..234b57982801 100644
--- a/fs/afs/yfsclient.c
+++ b/fs/afs/yfsclient.c
@@ -544,7 +544,7 @@ static int yfs_deliver_fs_fetch_data64(struct afs_call *call)
 		afs_extract_to_tmp64(call);
 		call->unmarshall++;
 
-		/* extract the returned data length */
+		/* Fall through - and extract the returned data length */
 	case 1:
 		_debug("extract data length");
 		ret = afs_extract_data(call, true);
@@ -571,7 +571,7 @@ static int yfs_deliver_fs_fetch_data64(struct afs_call *call)
 		iov_iter_bvec(&call->iter, READ, call->bvec, 1, size);
 		ASSERTCMP(size, <=, PAGE_SIZE);
 
-		/* extract the returned data */
+		/* Fall through - and extract the returned data */
 	case 2:
 		_debug("extract data %zu/%llu",
 		       iov_iter_count(&call->iter), req->remain);
@@ -598,6 +598,8 @@ static int yfs_deliver_fs_fetch_data64(struct afs_call *call)
 		/* Discard any excess data the server gave us */
 		iov_iter_discard(&call->iter, READ, req->actual_len - req->len);
 		call->unmarshall = 3;
+
+		/* Fall through */
 	case 3:
 		_debug("extract discard %zu/%llu",
 		       iov_iter_count(&call->iter), req->actual_len - req->len);
@@ -613,7 +615,7 @@ static int yfs_deliver_fs_fetch_data64(struct afs_call *call)
 				   sizeof(struct yfs_xdr_YFSCallBack) +
 				   sizeof(struct yfs_xdr_YFSVolSync));
 
-		/* extract the metadata */
+		/* Fall through - and extract the metadata */
 	case 4:
 		ret = afs_extract_data(call, false);
 		if (ret < 0)
@@ -629,6 +631,7 @@ static int yfs_deliver_fs_fetch_data64(struct afs_call *call)
 
 		call->unmarshall++;
 
+		/* Fall through */
 	case 5:
 		break;
 	}
@@ -1584,7 +1587,7 @@ static int yfs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->unmarshall++;
 		afs_extract_to_buf(call, sizeof(struct yfs_xdr_YFSFetchVolumeStatus));
 
-		/* extract the returned status record */
+		/* Fall through - and extract the returned status record */
 	case 1:
 		_debug("extract status");
 		ret = afs_extract_data(call, true);
@@ -1596,7 +1599,7 @@ static int yfs_deliver_fs_get_volume_status(struct afs_call *call)
 		call->unmarshall++;
 		afs_extract_to_tmp(call);
 
-		/* extract the volume name length */
+		/* Fall through - and extract the volume name length */
 	case 2:
 		ret = afs_extract_data(call, true);
 		if (ret < 0)
@@ -1611,7 +1614,7 @@ static int yfs_deliver_fs_get_volume_status(struct afs_call *call)
 		afs_extract_begin(call, call->reply[2], size);
 		call->unmarshall++;
 
-		/* extract the volume name */
+		/* Fall through - and extract the volume name */
 	case 3:
 		_debug("extract volname");
 		ret = afs_extract_data(call, true);
@@ -1624,7 +1627,7 @@ static int yfs_deliver_fs_get_volume_status(struct afs_call *call)
 		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
-		/* extract the offline message length */
+		/* Fall through - and extract the offline message length */
 	case 4:
 		ret = afs_extract_data(call, true);
 		if (ret < 0)
@@ -1639,7 +1642,7 @@ static int yfs_deliver_fs_get_volume_status(struct afs_call *call)
 		afs_extract_begin(call, call->reply[2], size);
 		call->unmarshall++;
 
-		/* extract the offline message */
+		/* Fall through - and extract the offline message */
 	case 5:
 		_debug("extract offline");
 		ret = afs_extract_data(call, true);
@@ -1653,7 +1656,7 @@ static int yfs_deliver_fs_get_volume_status(struct afs_call *call)
 		afs_extract_to_tmp(call);
 		call->unmarshall++;
 
-		/* extract the message of the day length */
+		/* Fall through - and extract the message of the day length */
 	case 6:
 		ret = afs_extract_data(call, true);
 		if (ret < 0)
@@ -1668,7 +1671,7 @@ static int yfs_deliver_fs_get_volume_status(struct afs_call *call)
 		afs_extract_begin(call, call->reply[2], size);
 		call->unmarshall++;
 
-		/* extract the message of the day */
+		/* Fall through - and extract the message of the day */
 	case 7:
 		_debug("extract motd");
 		ret = afs_extract_data(call, false);
@@ -1681,6 +1684,7 @@ static int yfs_deliver_fs_get_volume_status(struct afs_call *call)
 
 		call->unmarshall++;
 
+		/* Fall through */
 	case 8:
 		break;
 	}
@@ -2026,6 +2030,7 @@ static int yfs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		call->unmarshall++;
 
 		/* Extract the file status count and array in two steps */
+		/* Fall through */
 	case 1:
 		_debug("extract status count");
 		ret = afs_extract_data(call, true);
@@ -2043,6 +2048,7 @@ static int yfs_deliver_fs_inline_bulk_status(struct afs_call *call)
 	more_counts:
 		afs_extract_to_buf(call, sizeof(struct yfs_xdr_YFSFetchStatus));
 
+		/* Fall through */
 	case 2:
 		_debug("extract status array %u", call->count);
 		ret = afs_extract_data(call, true);
@@ -2066,6 +2072,7 @@ static int yfs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		afs_extract_to_tmp(call);
 
 		/* Extract the callback count and array in two steps */
+		/* Fall through */
 	case 3:
 		_debug("extract CB count");
 		ret = afs_extract_data(call, true);
@@ -2082,6 +2089,7 @@ static int yfs_deliver_fs_inline_bulk_status(struct afs_call *call)
 	more_cbs:
 		afs_extract_to_buf(call, sizeof(struct yfs_xdr_YFSCallBack));
 
+		/* Fall through */
 	case 4:
 		_debug("extract CB array");
 		ret = afs_extract_data(call, true);
@@ -2104,6 +2112,7 @@ static int yfs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		afs_extract_to_buf(call, sizeof(struct yfs_xdr_YFSVolSync));
 		call->unmarshall++;
 
+		/* Fall through */
 	case 5:
 		ret = afs_extract_data(call, false);
 		if (ret < 0)
@@ -2114,6 +2123,7 @@ static int yfs_deliver_fs_inline_bulk_status(struct afs_call *call)
 
 		call->unmarshall++;
 
+		/* Fall through */
 	case 6:
 		break;
 	}
-- 
2.20.1

Re: [PATCH] afs: Mark expected switch fall-throughs

[Kees Cook]

On Thu, Jan 10, 2019 at 2:02 PM Gustavo A. R. Silva
<gustavo@embeddedor.com> wrote:
> In preparation to enabling -Wimplicit-fallthrough, mark switch cases
> where we are expecting to fall through.
>
> Notice that in many cases I placed a /* Fall through */ comment
> at the bottom of the case, which what GCC is expecting to find.
>
> In other cases I had to tweak a bit the format of the comments.
>
> This patch suppresses ALL missing-break-in-switch false positives
> in fs/afs
>
> Addresses-Coverity-ID: 115042 ("Missing break in switch")
> Addresses-Coverity-ID: 115043 ("Missing break in switch")
> Addresses-Coverity-ID: 115045 ("Missing break in switch")
> Addresses-Coverity-ID: 1357430 ("Missing break in switch")
> Addresses-Coverity-ID: 115047 ("Missing break in switch")
> Addresses-Coverity-ID: 115050 ("Missing break in switch")
> Addresses-Coverity-ID: 115051 ("Missing break in switch")
> Addresses-Coverity-ID: 1467806 ("Missing break in switch")
> Addresses-Coverity-ID: 1467807 ("Missing break in switch")
> Addresses-Coverity-ID: 1467811 ("Missing break in switch")
> Addresses-Coverity-ID: 115041 ("Missing break in switch")
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

These look good to me. Gets us another step to finishing this. :)

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

Re: [PATCH] afs: Mark expected switch fall-throughs

[David Howells]

Kees Cook <keescook@google.com> wrote:

> These look good to me. Gets us another step to finishing this. :)

Can we fix the compiler, please, to say that *every* case (perhaps barring the
last) is expected to fall through?

David

Re: [PATCH] afs: Mark expected switch fall-throughs

[Kees Cook]

On Tue, Apr 9, 2019 at 2:28 AM David Howells <dhowells@redhat.com> wrote:
> Kees Cook <keescook@google.com> wrote:
>
> > These look good to me. Gets us another step to finishing this. :)
>
> Can we fix the compiler, please, to say that *every* case (perhaps barring the
> last) is expected to fall through?

Right now we're targeting both compilers and static analyzers. Neither
support this kind of marking, unfortunately. We can, however,
mechanically change this in the future if that becomes possible.

-- 
Kees Cook

Re: [PATCH] afs: Mark expected switch fall-throughs

[David Howells]

Kees Cook <keescook@google.com> wrote:

> > Can we fix the compiler, please, to say that *every* case (perhaps barring
> > the last) is expected to fall through?

I should say "... so that we can say that *every* case ...".

David

Re: [PATCH] afs: Mark expected switch fall-throughs

[David Howells]

Gustavo A. R. Silva <gustavo@embeddedor.com> wrote:

Please fix the compiler so that you can annotate a switch-statement to say
that every case must fall through (except, perhaps, the last).

>  		/* extract the FID array and its count in two steps */
> +		/* fall through */
>  	case 1:

Capitialise "Fall" for consistency, please, and can you put the fall-through
marker *before* the comment introducing the case please?  It belongs to the
preceding section.

>  		/* extract the callback array and its count in two steps */
> +		/* fall through */
>  	case 3:

Ditto.

>  		/* extract the FID array and its count in two steps */
> +		/* Fall through */

Ditto on putting the fall-through before the introductory comment.

(And more dittos).

> -		/* Extract fsEndpoints[] entries */
> +		/* Fall through - and extract fsEndpoints[] entries */

And here you're doing something different yet again, though you could drop
either the "-" or the "and".

David