[PATCH] ext4: fix debug format string warning

[PATCH] ext4: fix debug format string warning

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

Using no_printk() for jbd_debug() revealed two warnings:

fs/jbd2/recovery.c: In function 'fc_do_one_pass':
fs/jbd2/recovery.c:256:30: error: format '%d' expects a matching 'int' argument [-Werror=format=]
  256 |                 jbd_debug(3, "Processing fast commit blk with seq %d");
      |                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/ext4/fast_commit.c: In function 'ext4_fc_replay_add_range':
fs/ext4/fast_commit.c:1732:30: error: format '%d' expects argument of type 'int', but argument 2 has type 'long unsigned int' [-Werror=format=]
 1732 |                 jbd_debug(1, "Converting from %d to %d %lld",

The first one was added incorrectly, and was also missing a few newlines
in debug output, and the second one happened when the type of an
argument changed.

Reported-by: kernel test robot <lkp@intel.com>
Fixes: d556435156b7 ("jbd2: avoid -Wempty-body warnings")
Fixes: 6db074618969 ("ext4: use BIT() macro for BH_** state bits")
Fixes: 5b849b5f96b4 ("jbd2: fast commit recovery path")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 fs/ext4/fast_commit.c | 2 +-
 fs/jbd2/recovery.c    | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/ext4/fast_commit.c b/fs/ext4/fast_commit.c
index 6c4f19b0a556..feec2f3f13e9 100644
--- a/fs/ext4/fast_commit.c
+++ b/fs/ext4/fast_commit.c
@@ -1729,7 +1729,7 @@ static int ext4_fc_replay_add_range(struct super_block *sb,
 		}
 
 		/* Range is mapped and needs a state change */
-		jbd_debug(1, "Converting from %d to %d %lld",
+		jbd_debug(1, "Converting from %ld to %d %lld",
 				map.m_flags & EXT4_MAP_UNWRITTEN,
 			ext4_ext_is_unwritten(ex), map.m_pblk);
 		ret = ext4_ext_replay_update_ex(inode, cur, map.m_len,
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index 69f18fe20923..60601c5779f1 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -245,15 +245,15 @@ static int fc_do_one_pass(journal_t *journal,
 		return 0;
 
 	while (next_fc_block <= journal->j_fc_last) {
-		jbd_debug(3, "Fast commit replay: next block %ld",
+		jbd_debug(3, "Fast commit replay: next block %ld\n",
 			  next_fc_block);
 		err = jread(&bh, journal, next_fc_block);
 		if (err) {
-			jbd_debug(3, "Fast commit replay: read error");
+			jbd_debug(3, "Fast commit replay: read error\n");
 			break;
 		}
 
-		jbd_debug(3, "Processing fast commit blk with seq %d");
+		jbd_debug(3, "Processing fast commit blk with seq\n");
 		err = journal->j_fc_replay_callback(journal, bh, pass,
 					next_fc_block - journal->j_fc_first,
 					expected_commit_id);
-- 
2.29.2

Re: [PATCH] ext4: fix debug format string warning

[tytso]

On Fri, Apr 09, 2021 at 10:12:05PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> Using no_printk() for jbd_debug() revealed two warnings:
> 
> fs/jbd2/recovery.c: In function 'fc_do_one_pass':
> fs/jbd2/recovery.c:256:30: error: format '%d' expects a matching 'int' argument [-Werror=format=]
>   256 |                 jbd_debug(3, "Processing fast commit blk with seq %d");
>       |                              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> fs/ext4/fast_commit.c: In function 'ext4_fc_replay_add_range':
> fs/ext4/fast_commit.c:1732:30: error: format '%d' expects argument of type 'int', but argument 2 has type 'long unsigned int' [-Werror=format=]
>  1732 |                 jbd_debug(1, "Converting from %d to %d %lld",
> 
> The first one was added incorrectly, and was also missing a few newlines
> in debug output, and the second one happened when the type of an
> argument changed.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Fixes: d556435156b7 ("jbd2: avoid -Wempty-body warnings")
> Fixes: 6db074618969 ("ext4: use BIT() macro for BH_** state bits")
> Fixes: 5b849b5f96b4 ("jbd2: fast commit recovery path")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks, applied, with one change.

> diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
> index 69f18fe20923..60601c5779f1 100644
> --- a/fs/jbd2/recovery.c
> +++ b/fs/jbd2/recovery.c
> @@ -245,15 +245,15 @@ static int fc_do_one_pass(journal_t *journal,
>     ....
>  
>  		if (err) {
> -			jbd_debug(3, "Fast commit replay: read error");
> +			jbd_debug(3, "Fast commit replay: read error\n");
>  			break;
>  		}
>  
> -		jbd_debug(3, "Processing fast commit blk with seq %d");
> +		jbd_debug(3, "Processing fast commit blk with seq\n");

This debug statement isn't adding any real value, so I just removed
it.

				- Ted