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| author | Gustavo A. R. Silva <gustavoars@kernel.org> | 2021-02-24 13:03:13 -0600 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2021-03-12 13:16:42 -0800 |
| commit | 4260c4067fbba55a90037fe3ee32eff087749f83 (patch) | |
| tree | 21fd9bd6069df42095fae94ac544570dab3d9b3d | |
| parent | 72f85881249e3a7403434631b9a9f934cdd1a83d (diff) | |
| download | linux-4260c4067fbba55a90037fe3ee32eff087749f83.tar.gz linux-4260c4067fbba55a90037fe3ee32eff087749f83.tar.bz2 linux-4260c4067fbba55a90037fe3ee32eff087749f83.zip | |
f2fs: Replace one-element array with flexible-array member
There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].
Refactor the code according to the use of a flexible-array member in
struct f2fs_checkpoint, instead of a one-element arrays.
Notice that a temporary pointer to void '*tmp_ptr' was used in order to
fix the following errors when using a flexible array instead of a one
element array in struct f2fs_checkpoint:
CC [M] fs/f2fs/dir.o
In file included from fs/f2fs/dir.c:13:
fs/f2fs/f2fs.h: In function ‘__bitmap_ptr’:
fs/f2fs/f2fs.h:2227:40: error: invalid use of flexible array member
2227 | return &ckpt->sit_nat_version_bitmap + offset + sizeof(__le32);
| ^
fs/f2fs/f2fs.h:2227:49: error: invalid use of flexible array member
2227 | return &ckpt->sit_nat_version_bitmap + offset + sizeof(__le32);
| ^
fs/f2fs/f2fs.h:2238:40: error: invalid use of flexible array member
2238 | return &ckpt->sit_nat_version_bitmap + offset;
| ^
make[2]: *** [scripts/Makefile.build:287: fs/f2fs/dir.o] Error 1
make[1]: *** [scripts/Makefile.build:530: fs/f2fs] Error 2
make: *** [Makefile:1819: fs] Error 2
[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.9/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/79
Build-tested-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/603647e4.DeEFbl4eqljuwAUe%25lkp@intel.com/
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
| -rw-r--r-- | fs/f2fs/f2fs.h | 5 | ||||
| -rw-r--r-- | include/linux/f2fs_fs.h | 2 |
2 files changed, 4 insertions, 3 deletions
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index cccdfb1a40ab..99e243fd26d5 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -2215,6 +2215,7 @@ static inline block_t __cp_payload(struct f2fs_sb_info *sbi) static inline void *__bitmap_ptr(struct f2fs_sb_info *sbi, int flag) { struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi); + void *tmp_ptr = &ckpt->sit_nat_version_bitmap; int offset; if (is_set_ckpt_flags(sbi, CP_LARGE_NAT_BITMAP_FLAG)) { @@ -2224,7 +2225,7 @@ static inline void *__bitmap_ptr(struct f2fs_sb_info *sbi, int flag) * if large_nat_bitmap feature is enabled, leave checksum * protection for all nat/sit bitmaps. */ - return &ckpt->sit_nat_version_bitmap + offset + sizeof(__le32); + return tmp_ptr + offset + sizeof(__le32); } if (__cp_payload(sbi) > 0) { @@ -2235,7 +2236,7 @@ static inline void *__bitmap_ptr(struct f2fs_sb_info *sbi, int flag) } else { offset = (flag == NAT_BITMAP) ? le32_to_cpu(ckpt->sit_ver_bitmap_bytesize) : 0; - return &ckpt->sit_nat_version_bitmap + offset; + return tmp_ptr + offset; } } diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h index c6cc0a566ef5..5487a80617a3 100644 --- a/include/linux/f2fs_fs.h +++ b/include/linux/f2fs_fs.h @@ -168,7 +168,7 @@ struct f2fs_checkpoint { unsigned char alloc_type[MAX_ACTIVE_LOGS]; /* SIT and NAT version bitmap */ - unsigned char sit_nat_version_bitmap[1]; + unsigned char sit_nat_version_bitmap[]; } __packed; #define CP_CHKSUM_OFFSET 4092 /* default chksum offset in checkpoint */ |