diff options
| author | ZhaoLong Wang <wangzhaolong1@huawei.com> | 2024-04-18 09:07:04 +0200 |
|---|---|---|
| committer | Richard Weinberger <richard@nod.at> | 2024-07-12 21:52:24 +0200 |
| commit | 7037c96d8c42965eb93e6b96cf921399c283d431 (patch) | |
| tree | 6bc5045dce42aaf23882b5e9a0b4ec2811ad0651 /drivers | |
| parent | mtd: ubi: Restore missing cleanup on ubi_init() failure path (diff) | |
| download | linux-7037c96d8c42965eb93e6b96cf921399c283d431.tar.xz linux-7037c96d8c42965eb93e6b96cf921399c283d431.zip | |
ubifs: correct UBIFS_DFS_DIR_LEN macro definition and improve code clarity
The UBIFS_DFS_DIR_LEN macro, which defines the maximum length of the UBIFS
debugfs directory name, has an incorrect formula and misleading comments.
The current formula is (3 + 1 + 2*2 + 1), which assumes that both UBI device
number and volume ID are limited to 2 characters. However, UBI device number
ranges from 0 to 31 (2 characters), and volume ID ranges from 0 to 127 (up
to 3 characters).
Although the current code works due to the cancellation of mathematical
errors (9 + 1 = 10, which matches the correct UBIFS_DFS_DIR_LEN value), it
can lead to confusion and potential issues in the future.
This patch aims to improve the code clarity and maintainability by making
the following changes:
1. Corrects the UBIFS_DFS_DIR_LEN macro definition to (3 + 1 + 2 + 3 + 1),
accommodating the maximum lengths of both UBI device number and volume ID,
plus the separators and null terminator.
2. Updates the snprintf calls to use UBIFS_DFS_DIR_LEN instead of
UBIFS_DFS_DIR_LEN + 1, removing the unnecessary +1.
3. Modifies the error checks to compare against UBIFS_DFS_DIR_LEN using >=
instead of >, aligning with the corrected macro definition.
4. Removes the redundant +1 in the dfs_dir_name array definitions in ubi.h
and debug.h.
While these changes do not affect the runtime behavior, they make the code
more readable, maintainable, and less prone to future errors.
v2->v3:
- Removes the duplicated UBIFS_DFS_DIR_LEN and UBIFS_DFS_DIR_NAME macro
definitions in ubifs.h, as they are already defined in debug.h.
Signed-off-by: ZhaoLong Wang <wangzhaolong1@huawei.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mtd/ubi/debug.c | 4 | ||||
| -rw-r--r-- | drivers/mtd/ubi/ubi.h | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c index d57f52bd2ff3..9ec3b8b6a0aa 100644 --- a/drivers/mtd/ubi/debug.c +++ b/drivers/mtd/ubi/debug.c @@ -598,9 +598,9 @@ int ubi_debugfs_init_dev(struct ubi_device *ubi) if (!IS_ENABLED(CONFIG_DEBUG_FS)) return 0; - n = snprintf(d->dfs_dir_name, UBI_DFS_DIR_LEN + 1, UBI_DFS_DIR_NAME, + n = snprintf(d->dfs_dir_name, UBI_DFS_DIR_LEN, UBI_DFS_DIR_NAME, ubi->ubi_num); - if (n > UBI_DFS_DIR_LEN) { + if (n >= UBI_DFS_DIR_LEN) { /* The array size is too small */ return -EINVAL; } diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h index 1aead55090d0..1c9e874e8ede 100644 --- a/drivers/mtd/ubi/ubi.h +++ b/drivers/mtd/ubi/ubi.h @@ -420,7 +420,7 @@ struct ubi_debug_info { unsigned int power_cut_min; unsigned int power_cut_max; unsigned int emulate_failures; - char dfs_dir_name[UBI_DFS_DIR_LEN + 1]; + char dfs_dir_name[UBI_DFS_DIR_LEN]; struct dentry *dfs_dir; struct dentry *dfs_chk_gen; struct dentry *dfs_chk_io; |