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| author | Josef Bacik <josef@toxicpanda.com> | 2023-09-05 12:15:23 -0400 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2023-09-21 18:52:20 +0200 |
| commit | 20218dfbaa31b8d3ef842fafcc7eb4c6aa03f80a (patch) | |
| tree | 3e6af844981424f93aad1f799e7b053d46926e3d | |
| parent | 74ee79142c0a344d4eae2eb7012ebc4e82254109 (diff) | |
| download | linux-20218dfbaa31b8d3ef842fafcc7eb4c6aa03f80a.tar.gz linux-20218dfbaa31b8d3ef842fafcc7eb4c6aa03f80a.tar.bz2 linux-20218dfbaa31b8d3ef842fafcc7eb4c6aa03f80a.zip | |
btrfs: make sure to initialize start and len in find_free_dev_extent
Jens reported a compiler error when using CONFIG_CC_OPTIMIZE_FOR_SIZE=y
that looks like this
In function ‘gather_device_info’,
inlined from ‘btrfs_create_chunk’ at fs/btrfs/volumes.c:5507:8:
fs/btrfs/volumes.c:5245:48: warning: ‘dev_offset’ may be used uninitialized [-Wmaybe-uninitialized]
5245 | devices_info[ndevs].dev_offset = dev_offset;
| ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~
fs/btrfs/volumes.c: In function ‘btrfs_create_chunk’:
fs/btrfs/volumes.c:5196:13: note: ‘dev_offset’ was declared here
5196 | u64 dev_offset;
This occurs because find_free_dev_extent is responsible for setting
dev_offset, however if we get an -ENOMEM at the top of the function
we'll return without setting the value.
This isn't actually a problem because we will see the -ENOMEM in
gather_device_info() and return and not use the uninitialized value,
however we also just don't want the compiler warning so rework the code
slightly in find_free_dev_extent() to make sure it's always setting
*start and *len to avoid the compiler warning.
Reported-by: Jens Axboe <axboe@kernel.dk>
Tested-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
| -rw-r--r-- | fs/btrfs/volumes.c | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 733842136163..e3a3769fd92e 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1594,7 +1594,7 @@ static int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes, u64 search_start; u64 hole_size; u64 max_hole_start; - u64 max_hole_size; + u64 max_hole_size = 0; u64 extent_end; u64 search_end = device->total_bytes; int ret; @@ -1602,17 +1602,16 @@ static int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes, struct extent_buffer *l; search_start = dev_extent_search_start(device); + max_hole_start = search_start; WARN_ON(device->zone_info && !IS_ALIGNED(num_bytes, device->zone_info->zone_size)); path = btrfs_alloc_path(); - if (!path) - return -ENOMEM; - - max_hole_start = search_start; - max_hole_size = 0; - + if (!path) { + ret = -ENOMEM; + goto out; + } again: if (search_start >= search_end || test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) { |