[PATCH 0/2] btrfs-progs: -Wshadow fixes

[PATCH 0/2] btrfs-progs: -Wshadow fixes

[Qu Wenruo]

Since -Wshadow is enabled recently, there are two new warnings:

- @e from cmd_inspect_list_chunks()
- @csum from print_header_info()
  This needs experimental features to be enabled

Just fix them all.

Qu Wenruo (2):
  btrfs-progs: remove variable e from cmd_inspect_list_chunks()
  btrfs-progs: fix a variable shadowing when enabling experimental
    features

 cmds/inspect.c             | 4 +---
 kernel-shared/print-tree.c | 4 ++--
 2 files changed, 3 insertions(+), 5 deletions(-)

--
2.42.0

[PATCH 1/2] btrfs-progs: remove variable e from cmd_inspect_list_chunks()

[Qu Wenruo]

The variable @e is only utilized to record the errno from ioctl() call,
and is only for the error message.

We can go with "%m" to replace the usage of variable @e, and remove the
variable shadowing, as later we will declare a local variable @e with a
different type.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 cmds/inspect.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/cmds/inspect.c b/cmds/inspect.c
index ef928895fa08..50f1ddc745a6 100644
--- a/cmds/inspect.c
+++ b/cmds/inspect.c
@@ -1026,7 +1026,6 @@ static int cmd_inspect_list_chunks(const struct cmd_struct *cmd,
 	int ret;
 	int fd;
 	int i;
-	int e;
 	DIR *dirstream = NULL;
 	unsigned unit_mode;
 	char *sortmode = NULL;
@@ -1114,9 +1113,8 @@ static int cmd_inspect_list_chunks(const struct cmd_struct *cmd,
 	while (1) {
 		sk->nr_items = 1;
 		ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
-		e = errno;
 		if (ret < 0) {
-			error("cannot perform the search: %s", strerror(e));
+			error("cannot perform the search: %m");
 			return 1;
 		}
 		if (sk->nr_items == 0)
-- 
2.42.0

[PATCH 2/2] btrfs-progs: fix a variable shadowing when enabling experimental features

[Qu Wenruo]

There is another variable shadowing problem which can only be exposed
if experimental features are enabled.

Inside the branch of BTRFS_PRINT_TREE_CSUM_HEADERS, we declare another
local variable @csum, shadowing the @csum of print_header_info(), which
is only declared when experimental features are enabled.

Just rename the @csum to @tree_csum to avoid the problem.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 kernel-shared/print-tree.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel-shared/print-tree.c b/kernel-shared/print-tree.c
index 8511cb1bfd6c..6625b1b6aa80 100644
--- a/kernel-shared/print-tree.c
+++ b/kernel-shared/print-tree.c
@@ -1271,12 +1271,12 @@ static void print_header_info(struct extent_buffer *eb, unsigned int mode)
 	printf("\n");
 	if (fs_info && (mode & BTRFS_PRINT_TREE_CSUM_HEADERS)) {
 		char *tmp = csum_str;
-		u8 *csum = (u8 *)(eb->data + offsetof(struct btrfs_header, csum));
+		u8 *tree_csum = (u8 *)(eb->data + offsetof(struct btrfs_header, csum));
 
 		strcpy(csum_str, " csum 0x");
 		tmp = csum_str + strlen(csum_str);
 		for (i = 0; i < csum_size; i++) {
-			sprintf(tmp, "%02x", csum[i]);
+			sprintf(tmp, "%02x", tree_csum[i]);
 			tmp++;
 			tmp++;
 		}
-- 
2.42.0

Re: [PATCH 0/2] btrfs-progs: -Wshadow fixes

[David Sterba]

On Thu, Sep 28, 2023 at 01:36:32PM +0930, Qu Wenruo wrote:
> Since -Wshadow is enabled recently, there are two new warnings:
> 
> - @e from cmd_inspect_list_chunks()
> - @csum from print_header_info()
>   This needs experimental features to be enabled
> 
> Just fix them all.
> 
> Qu Wenruo (2):
>   btrfs-progs: remove variable e from cmd_inspect_list_chunks()
>   btrfs-progs: fix a variable shadowing when enabling experimental
>     features

Added to devel, thanks.