erofs: silence uninitialized variable warning in z_erofs_scan_folio()

[PATCH] erofs: silence uninitialized variable warning in z_erofs_scan_folio()

Posted by Dan Carpenter 1 year, 5 months ago

Smatch complains that:

    fs/erofs/zdata.c:1047 z_erofs_scan_folio()
    error: uninitialized symbol 'err'.

The issue is if we hit this (!(map->m_flags & EROFS_MAP_MAPPED)) {
condition then "err" isn't set.  It's inside a loop so we would have to
hit that condition on every iteration.  Initialize "err" to zero to
solve this.

Fixes: 5b9654efb604 ("erofs: teach z_erofs_scan_folios() to handle multi-page folios")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 fs/erofs/zdata.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index aff3cdf114ad..ac5ffd4674e4 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -962,7 +962,7 @@ static int z_erofs_scan_folio(struct z_erofs_decompress_frontend *f,
 	const unsigned int bs = i_blocksize(inode);
 	unsigned int end = folio_size(folio), split = 0, cur, pgs;
 	bool tight, excl;
-	int err;
+	int err = 0;
 
 	tight = (bs == PAGE_SIZE);
 	z_erofs_onlinefolio_init(folio);
-- 
2.43.0

Re: [PATCH] erofs: silence uninitialized variable warning in z_erofs_scan_folio()

Posted by Gao Xiang 1 year, 5 months ago


On 2024/7/13 09:04, Dan Carpenter wrote:
> Smatch complains that:
> 
>      fs/erofs/zdata.c:1047 z_erofs_scan_folio()
>      error: uninitialized symbol 'err'.
> 
> The issue is if we hit this (!(map->m_flags & EROFS_MAP_MAPPED)) {
> condition then "err" isn't set.  It's inside a loop so we would have to
> hit that condition on every iteration.  Initialize "err" to zero to
> solve this.
> 
> Fixes: 5b9654efb604 ("erofs: teach z_erofs_scan_folios() to handle multi-page folios")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>

Thanks, applied.

Thanks,
Gao Xiang