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author | ZhaoLong Wang <wangzhaolong1@huawei.com> | 2024-04-18 15:07:04 +0800 |
---|---|---|
committer | Richard Weinberger <richard@nod.at> | 2024-07-12 21:52:24 +0200 |
commit | 7037c96d8c42965eb93e6b96cf921399c283d431 (patch) | |
tree | 6bc5045dce42aaf23882b5e9a0b4ec2811ad0651 /fs/ubifs | |
parent | 72f3d3daddd740f744a24cd7ef8c27bd0cd5489d (diff) | |
download | linux-7037c96d8c42965eb93e6b96cf921399c283d431.tar.gz linux-7037c96d8c42965eb93e6b96cf921399c283d431.tar.bz2 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 'fs/ubifs')
-rw-r--r-- | fs/ubifs/debug.c | 4 | ||||
-rw-r--r-- | fs/ubifs/debug.h | 7 | ||||
-rw-r--r-- | fs/ubifs/sysfs.c | 6 | ||||
-rw-r--r-- | fs/ubifs/ubifs.h | 7 |
4 files changed, 9 insertions, 15 deletions
diff --git a/fs/ubifs/debug.c b/fs/ubifs/debug.c index ac77ac1fd73e..d91cec93d968 100644 --- a/fs/ubifs/debug.c +++ b/fs/ubifs/debug.c @@ -2827,9 +2827,9 @@ void dbg_debugfs_init_fs(struct ubifs_info *c) const char *fname; struct ubifs_debug_info *d = c->dbg; - n = snprintf(d->dfs_dir_name, UBIFS_DFS_DIR_LEN + 1, UBIFS_DFS_DIR_NAME, + n = snprintf(d->dfs_dir_name, UBIFS_DFS_DIR_LEN, UBIFS_DFS_DIR_NAME, c->vi.ubi_num, c->vi.vol_id); - if (n > UBIFS_DFS_DIR_LEN) { + if (n >= UBIFS_DFS_DIR_LEN) { /* The array size is too small */ return; } diff --git a/fs/ubifs/debug.h b/fs/ubifs/debug.h index ed966108da80..d425861e6b82 100644 --- a/fs/ubifs/debug.h +++ b/fs/ubifs/debug.h @@ -19,10 +19,11 @@ typedef int (*dbg_znode_callback)(struct ubifs_info *c, /* * The UBIFS debugfs directory name pattern and maximum name length (3 for "ubi" - * + 1 for "_" and plus 2x2 for 2 UBI numbers and 1 for the trailing zero byte. + * + 1 for "_" and 2 for UBI device numbers and 3 for volume number and 1 for + * the trailing zero byte. */ #define UBIFS_DFS_DIR_NAME "ubi%d_%d" -#define UBIFS_DFS_DIR_LEN (3 + 1 + 2*2 + 1) +#define UBIFS_DFS_DIR_LEN (3 + 1 + 2 + 3 + 1) /** * ubifs_debug_info - per-FS debugging information. @@ -103,7 +104,7 @@ struct ubifs_debug_info { unsigned int chk_fs:1; unsigned int tst_rcvry:1; - char dfs_dir_name[UBIFS_DFS_DIR_LEN + 1]; + char dfs_dir_name[UBIFS_DFS_DIR_LEN]; struct dentry *dfs_dir; struct dentry *dfs_dump_lprops; struct dentry *dfs_dump_budg; diff --git a/fs/ubifs/sysfs.c b/fs/ubifs/sysfs.c index 1c958148bb87..aae32222f11b 100644 --- a/fs/ubifs/sysfs.c +++ b/fs/ubifs/sysfs.c @@ -91,17 +91,17 @@ static struct kset ubifs_kset = { int ubifs_sysfs_register(struct ubifs_info *c) { int ret, n; - char dfs_dir_name[UBIFS_DFS_DIR_LEN+1]; + char dfs_dir_name[UBIFS_DFS_DIR_LEN]; c->stats = kzalloc(sizeof(struct ubifs_stats_info), GFP_KERNEL); if (!c->stats) { ret = -ENOMEM; goto out_last; } - n = snprintf(dfs_dir_name, UBIFS_DFS_DIR_LEN + 1, UBIFS_DFS_DIR_NAME, + n = snprintf(dfs_dir_name, UBIFS_DFS_DIR_LEN, UBIFS_DFS_DIR_NAME, c->vi.ubi_num, c->vi.vol_id); - if (n > UBIFS_DFS_DIR_LEN) { + if (n >= UBIFS_DFS_DIR_LEN) { /* The array size is too small */ ret = -EINVAL; goto out_free; diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index b2c6554fa857..d69a5a42d693 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -158,13 +158,6 @@ #endif /* - * The UBIFS sysfs directory name pattern and maximum name length (3 for "ubi" - * + 1 for "_" and plus 2x2 for 2 UBI numbers and 1 for the trailing zero byte. - */ -#define UBIFS_DFS_DIR_NAME "ubi%d_%d" -#define UBIFS_DFS_DIR_LEN (3 + 1 + 2*2 + 1) - -/* * Lockdep classes for UBIFS inode @ui_mutex. */ enum { |