xfs: Fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix
the following warnings by replacing /* fall through */ comments,
and its variants, with the new pseudo-keyword macro fallthrough:

fs/xfs/libxfs/xfs_alloc.c:3167:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_da_btree.c:286:3: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_ag_resv.c:346:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/libxfs/xfs_ag_resv.c:388:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_bmap_util.c:246:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_export.c:88:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_export.c:96:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_file.c:867:3: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_ioctl.c:562:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_ioctl.c:1548:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_iomap.c:1040:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_inode.c:852:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_log.c:2627:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/xfs_trans_buf.c:298:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/bmap.c:275:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/btree.c:48:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/common.c:85:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/common.c:138:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/common.c:698:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/dabtree.c:51:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/repair.c:951:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
fs/xfs/scrub/agheader.c:89:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]

Notice that Clang doesn't recognize /* fall through */ comments as
implicit fall-through markings, so in order to globally enable
-Wimplicit-fallthrough for Clang, these comments need to be
replaced with fallthrough; in the whole codebase.

Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

6 files changed, 8 insertions, 7 deletions

diff --git a/fs/xfs/scrub/agheader.c b/fs/xfs/scrub/agheader.c
index 7a2f9b5f2db5..f96e84793cc9 100644
--- a/fs/xfs/scrub/agheader.c
+++ b/fs/xfs/scrub/agheader.c
@@ -86,6 +86,7 @@ xchk_superblock(
 	case -ENOSYS:
 	case -EFBIG:
 		error = -EFSCORRUPTED;
+		fallthrough;
 	default:
 		break;
 	}
diff --git a/fs/xfs/scrub/bmap.c b/fs/xfs/scrub/bmap.c
index b5ebf1d1b4db..77d5c4a0f09f 100644
--- a/fs/xfs/scrub/bmap.c
+++ b/fs/xfs/scrub/bmap.c
@@ -271,7 +271,7 @@ xchk_bmap_iextent_xref(
 	case XFS_DATA_FORK:
 		if (xfs_is_reflink_inode(info->sc->ip))
 			break;
-		/* fall through */
+		fallthrough;
 	case XFS_ATTR_FORK:
 		xchk_xref_is_not_shared(info->sc, agbno,
 				irec->br_blockcount);
diff --git a/fs/xfs/scrub/btree.c b/fs/xfs/scrub/btree.c
index a94bd8122c60..bd1172358964 100644
--- a/fs/xfs/scrub/btree.c
+++ b/fs/xfs/scrub/btree.c
@@ -44,7 +44,7 @@ __xchk_btree_process_error(
 		/* Note the badness but don't abort. */
 		sc->sm->sm_flags |= errflag;
 		*error = 0;
-		/* fall through */
+		fallthrough;
 	default:
 		if (cur->bc_flags & XFS_BTREE_ROOT_IN_INODE)
 			trace_xchk_ifork_btree_op_error(sc, cur, level,
diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
index aa874607618a..ce9a44ea6948 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -81,7 +81,7 @@ __xchk_process_error(
 		/* Note the badness but don't abort. */
 		sc->sm->sm_flags |= errflag;
 		*error = 0;
-		/* fall through */
+		fallthrough;
 	default:
 		trace_xchk_op_error(sc, agno, bno, *error,
 				ret_ip);
@@ -134,7 +134,7 @@ __xchk_fblock_process_error(
 		/* Note the badness but don't abort. */
 		sc->sm->sm_flags |= errflag;
 		*error = 0;
-		/* fall through */
+		fallthrough;
 	default:
 		trace_xchk_file_op_error(sc, whichfork, offset, *error,
 				ret_ip);
@@ -694,7 +694,7 @@ xchk_get_inode(
 		if (error)
 			return -ENOENT;
 		error = -EFSCORRUPTED;
-		/* fall through */
+		fallthrough;
 	default:
 		trace_xchk_op_error(sc,
 				XFS_INO_TO_AGNO(mp, sc->sm->sm_ino),
diff --git a/fs/xfs/scrub/dabtree.c b/fs/xfs/scrub/dabtree.c
index 653f3280e1c1..9f0dbb47c82c 100644
--- a/fs/xfs/scrub/dabtree.c
+++ b/fs/xfs/scrub/dabtree.c
@@ -47,7 +47,7 @@ xchk_da_process_error(
 		/* Note the badness but don't abort. */
 		sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
 		*error = 0;
-		/* fall through */
+		fallthrough;
 	default:
 		trace_xchk_file_op_error(sc, ds->dargs.whichfork,
 				xfs_dir2_da_to_db(ds->dargs.geo,
diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
index c2857d854c83..b8202dd08939 100644
--- a/fs/xfs/scrub/repair.c
+++ b/fs/xfs/scrub/repair.c
@@ -947,7 +947,7 @@ xrep_ino_dqattach(
 			xrep_force_quotacheck(sc, XFS_DQTYPE_GROUP);
 		if (XFS_IS_PQUOTA_ON(sc->mp) && !sc->ip->i_pdquot)
 			xrep_force_quotacheck(sc, XFS_DQTYPE_PROJ);
-		/* fall through */
+		fallthrough;
 	case -ESRCH:
 		error = 0;
 		break;