| Message ID | 1619691320-81639-1-git-send-email-jiapeng.chong@linux.alibaba.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: Remove redundant assignment to ret | expand |
On Thu, Apr 29, 2021 at 06:15:20PM +0800, Jiapeng Chong wrote: > Variable ret is set to zero but this value is never read as it > is overwritten or not used later on, hence it is a redundant > assignment and can be removed. > > Cleans up the following clang-analyzer warning: I've looked at clang analyzer warnings in the past and the dead stores were ones of the least useful, namely because of the return value assignments. > fs/btrfs/volumes.c:8019:4: warning: Value stored to 'ret' is never read > [clang-analyzer-deadcode.DeadStores]. > > fs/btrfs/volumes.c:4757:4: warning: Value stored to 'ret' is never read > [clang-analyzer-deadcode.DeadStores]. > > fs/btrfs/volumes.c:7951:4: warning: Value stored to 'ret' is never read > [clang-analyzer-deadcode.DeadStores]. > > Reported-by: Abaci Robot <abaci@linux.alibaba.com> > Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> > --- > fs/btrfs/volumes.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c > index 9a1ead0..30504fa 100644 > --- a/fs/btrfs/volumes.c > +++ b/fs/btrfs/volumes.c > @@ -4754,7 +4754,6 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size) > mutex_unlock(&fs_info->reclaim_bgs_lock); > if (ret < 0) > goto done; > - ret = 0; > btrfs_release_path(path); > break; So this is a code pattern where 'ret' is used for some local function call but we want to make sure it does not go outside of the block as a non-zero value, potentially being returned from the whole function. No harm done if the value is not used later. > } > @@ -7939,7 +7938,7 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info) > struct btrfs_key key; > u64 prev_devid = 0; > u64 prev_dev_ext_end = 0; > - int ret = 0; > + int ret; Similar here, initializing ret to zero does no harm. We've had compiler warnings about unitialized ret when some error path was jumping around it. > > /* > * We don't have a dev_root because we mounted with ignorebadroots and > @@ -8016,7 +8015,6 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info) > if (ret < 0) > goto out; > if (ret > 0) { > - ret = 0; > break; > } Same pattern as in the first case.
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 9a1ead0..30504fa 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4754,7 +4754,6 @@ int btrfs_shrink_device(struct btrfs_device *device, u64 new_size) mutex_unlock(&fs_info->reclaim_bgs_lock); if (ret < 0) goto done; - ret = 0; btrfs_release_path(path); break; } @@ -7939,7 +7938,7 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info) struct btrfs_key key; u64 prev_devid = 0; u64 prev_dev_ext_end = 0; - int ret = 0; + int ret; /* * We don't have a dev_root because we mounted with ignorebadroots and @@ -8016,7 +8015,6 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info) if (ret < 0) goto out; if (ret > 0) { - ret = 0; break; } }
Variable ret is set to zero but this value is never read as it is overwritten or not used later on, hence it is a redundant assignment and can be removed. Cleans up the following clang-analyzer warning: fs/btrfs/volumes.c:8019:4: warning: Value stored to 'ret' is never read [clang-analyzer-deadcode.DeadStores]. fs/btrfs/volumes.c:4757:4: warning: Value stored to 'ret' is never read [clang-analyzer-deadcode.DeadStores]. fs/btrfs/volumes.c:7951:4: warning: Value stored to 'ret' is never read [clang-analyzer-deadcode.DeadStores]. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> --- fs/btrfs/volumes.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)