Re: [PATCH][next] xfs: Fix fall-through warnings for Clang

Gustavo A. R. Silva
2021-04-21T00:18:51Z

On 4/20/21 18:38, Darrick J. Wong wrote:
> On Tue, Apr 20, 2021 at 06:06:52PM -0500, Gustavo A. R. Silva wrote:
>> 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]
>>
>> 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>
>
> I've already NAKd this twice, so I guess I'll NAK it a third time.

Darrick,

The adoption of fallthrough; has been already accepted and in use since Linux v5.7:

https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

This change is needed, and I would really prefer if this goes upstream through your tree.

Linus has taken these patches directly for a while, now.

Could you consider taking it this time? :)

Thanks
--
Gustavo

>
> --D
>
>> ---
>> fs/xfs/libxfs/xfs_ag_resv.c | 4 ++--
>> fs/xfs/libxfs/xfs_alloc.c | 2 +-
>> fs/xfs/libxfs/xfs_da_btree.c | 2 +-
>> fs/xfs/scrub/bmap.c | 2 +-
>> fs/xfs/scrub/btree.c | 2 +-
>> fs/xfs/scrub/common.c | 6 +++---
>> fs/xfs/scrub/dabtree.c | 2 +-
>> fs/xfs/scrub/repair.c | 2 +-
>> fs/xfs/xfs_bmap_util.c | 2 +-
>> fs/xfs/xfs_export.c | 4 ++--
>> fs/xfs/xfs_file.c | 2 +-
>> fs/xfs/xfs_inode.c | 2 +-
>> fs/xfs/xfs_ioctl.c | 4 ++--
>> fs/xfs/xfs_iomap.c | 2 +-
>> fs/xfs/xfs_trans_buf.c | 2 +-
>> 15 files changed, 20 insertions(+), 20 deletions(-)
>>
>> diff --git a/fs/xfs/libxfs/xfs_ag_resv.c b/fs/xfs/libxfs/xfs_ag_resv.c
>> index 6c5f8d10589c..8c3c99a9bf83 100644
>> --- a/fs/xfs/libxfs/xfs_ag_resv.c
>> +++ b/fs/xfs/libxfs/xfs_ag_resv.c
>> @@ -342,7 +342,7 @@ xfs_ag_resv_alloc_extent(
>> break;
>> default:
>> ASSERT(0);
>> - /* fall through */
>> + fallthrough;
>> case XFS_AG_RESV_NONE:
>> field = args->wasdel ? XFS_TRANS_SB_RES_FDBLOCKS :
>> XFS_TRANS_SB_FDBLOCKS;
>> @@ -384,7 +384,7 @@ xfs_ag_resv_free_extent(
>> break;
>> default:
>> ASSERT(0);
>> - /* fall through */
>> + fallthrough;
>> case XFS_AG_RESV_NONE:
>> xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, (int64_t)len);
>> return;
>> diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
>> index aaa19101bb2a..9eabdeeec492 100644
>> --- a/fs/xfs/libxfs/xfs_alloc.c
>> +++ b/fs/xfs/libxfs/xfs_alloc.c
>> @@ -3163,7 +3163,7 @@ xfs_alloc_vextent(
>> }
>> args->agbno = XFS_FSB_TO_AGBNO(mp, args->fsbno);
>> args->type = XFS_ALLOCTYPE_NEAR_BNO;
>> - /* FALLTHROUGH */
>> + fallthrough;
>> case XFS_ALLOCTYPE_FIRST_AG:
>> /*
>> * Rotate through the allocation groups looking for a winner.
>> diff --git a/fs/xfs/libxfs/xfs_da_btree.c b/fs/xfs/libxfs/xfs_da_btree.c
>> index 83ac9771bfb5..747ec77912c3 100644
>> --- a/fs/xfs/libxfs/xfs_da_btree.c
>> +++ b/fs/xfs/libxfs/xfs_da_btree.c
>> @@ -282,7 +282,7 @@ xfs_da3_node_read_verify(
>> __this_address);
>> break;
>> }
>> - /* fall through */
>> + fallthrough;
>> case XFS_DA_NODE_MAGIC:
>> fa = xfs_da3_node_verify(bp);
>> if (fa)
>> 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;
>> diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
>> index a5e9d7d34023..cc628475f9b6 100644
>> --- a/fs/xfs/xfs_bmap_util.c
>> +++ b/fs/xfs/xfs_bmap_util.c
>> @@ -242,7 +242,7 @@ xfs_bmap_count_blocks(
>> */
>> *count += btblocks - 1;
>>
>> - /* fall through */
>> + fallthrough;
>> case XFS_DINODE_FMT_EXTENTS:
>> *nextents = xfs_bmap_count_leaves(ifp, count);
>> break;
>> diff --git a/fs/xfs/xfs_export.c b/fs/xfs/xfs_export.c
>> index 465fd9e048d4..1da59bdff245 100644
>> --- a/fs/xfs/xfs_export.c
>> +++ b/fs/xfs/xfs_export.c
>> @@ -84,7 +84,7 @@ xfs_fs_encode_fh(
>> case FILEID_INO32_GEN_PARENT:
>> fid->i32.parent_ino = XFS_I(parent)->i_ino;
>> fid->i32.parent_gen = parent->i_generation;
>> - /*FALLTHRU*/
>> + fallthrough;
>> case FILEID_INO32_GEN:
>> fid->i32.ino = XFS_I(inode)->i_ino;
>> fid->i32.gen = inode->i_generation;
>> @@ -92,7 +92,7 @@ xfs_fs_encode_fh(
>> case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
>> fid64->parent_ino = XFS_I(parent)->i_ino;
>> fid64->parent_gen = parent->i_generation;
>> - /*FALLTHRU*/
>> + fallthrough;
>> case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
>> fid64->ino = XFS_I(inode)->i_ino;
>> fid64->gen = inode->i_generation;
>> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
>> index 396ef36dcd0a..3c0749ab9e40 100644
>> --- a/fs/xfs/xfs_file.c
>> +++ b/fs/xfs/xfs_file.c
>> @@ -863,7 +863,7 @@ xfs_break_layouts(
>> error = xfs_break_dax_layouts(inode, &retry);
>> if (error || retry)
>> break;
>> - /* fall through */
>> + fallthrough;
>> case BREAK_WRITE:
>> error = xfs_break_leased_layouts(inode, iolock, &retry);
>> break;
>> diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
>> index 0369eb22c1bb..f2846997c3a8 100644
>> --- a/fs/xfs/xfs_inode.c
>> +++ b/fs/xfs/xfs_inode.c
>> @@ -848,7 +848,7 @@ xfs_init_new_inode(
>> xfs_inode_inherit_flags(ip, pip);
>> if (pip && (pip->i_diflags2 & XFS_DIFLAG2_ANY))
>> xfs_inode_inherit_flags2(ip, pip);
>> - /* FALLTHROUGH */
>> + fallthrough;
>> case S_IFLNK:
>> ip->i_df.if_format = XFS_DINODE_FMT_EXTENTS;
>> ip->i_df.if_bytes = 0;
>> diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
>> index 3925bfcb2365..c4dc6c72ac37 100644
>> --- a/fs/xfs/xfs_ioctl.c
>> +++ b/fs/xfs/xfs_ioctl.c
>> @@ -558,7 +558,7 @@ xfs_ioc_attrmulti_one(
>> case ATTR_OP_REMOVE:
>> value = NULL;
>> *len = 0;
>> - /* fall through */
>> + fallthrough;
>> case ATTR_OP_SET:
>> error = mnt_want_write_file(parfilp);
>> if (error)
>> @@ -1544,7 +1544,7 @@ xfs_ioc_getbmap(
>> switch (cmd) {
>> case XFS_IOC_GETBMAPA:
>> bmx.bmv_iflags = BMV_IF_ATTRFORK;
>> - /*FALLTHRU*/
>> + fallthrough;
>> case XFS_IOC_GETBMAP:
>> /* struct getbmap is a strict subset of struct getbmapx. */
>> recsize = sizeof(struct getbmap);
>> diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
>> index d154f42e2dc6..d8cd2583dedb 100644
>> --- a/fs/xfs/xfs_iomap.c
>> +++ b/fs/xfs/xfs_iomap.c
>> @@ -1036,7 +1036,7 @@ xfs_buffered_write_iomap_begin(
>> prealloc_blocks = 0;
>> goto retry;
>> }
>> - /*FALLTHRU*/
>> + fallthrough;
>> default:
>> goto out_unlock;
>> }
>> diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
>> index 9aced0a00003..d11d032da0b4 100644
>> --- a/fs/xfs/xfs_trans_buf.c
>> +++ b/fs/xfs/xfs_trans_buf.c
>> @@ -294,7 +294,7 @@ xfs_trans_read_buf_map(
>> default:
>> if (tp && (tp->t_flags & XFS_TRANS_DIRTY))
>> xfs_force_shutdown(tp->t_mountp, SHUTDOWN_META_IO_ERROR);
>> - /* fall through */
>> + fallthrough;
>> case -ENOMEM:
>> case -EAGAIN:
>> return error;
>> --
>> 2.27.0
>>