Re: [PATCH] f2fs: support F2FS_NOLINEAR_LOOKUP_FL
From: Chao Yu
Date: Wed Mar 05 2025 - 03:25:04 EST
On 3/4/25 07:06, Eric Biggers wrote:
> On Mon, Mar 03, 2025 at 11:46:06AM +0800, Chao Yu via Linux-f2fs-devel wrote:
>> This patch introduces a new flag F2FS_NOLINEAR_LOOKUP_FL, so that we can
>> tag casefolded directory w/ it to disable linear lookup functionality,
>> it can be used for QA.
>>
>> Signed-off-by: Chao Yu <chao@xxxxxxxxxx>
>> ---
>> fs/f2fs/dir.c | 3 ++-
>> fs/f2fs/f2fs.h | 2 ++
>> fs/f2fs/file.c | 36 +++++++++++++++++++++++-------------
>> include/uapi/linux/f2fs.h | 5 +++++
>> 4 files changed, 32 insertions(+), 14 deletions(-)
>>
>> diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
>> index 54dd52de7269..4c74f29a2c73 100644
>> --- a/fs/f2fs/dir.c
>> +++ b/fs/f2fs/dir.c
>> @@ -366,7 +366,8 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir,
>>
>> out:
>> #if IS_ENABLED(CONFIG_UNICODE)
>> - if (IS_CASEFOLDED(dir) && !de && use_hash) {
>> + if (IS_CASEFOLDED(dir) && !de && use_hash &&
>> + !IS_NOLINEAR_LOOKUP(dir)) {
>> use_hash = false;
>> goto start_find_entry;
>> }
>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>> index 05879c6dc4d6..787f1e5a52d7 100644
>> --- a/fs/f2fs/f2fs.h
>> +++ b/fs/f2fs/f2fs.h
>> @@ -3047,6 +3047,7 @@ static inline void f2fs_change_bit(unsigned int nr, char *addr)
>> #define F2FS_NOCOMP_FL 0x00000400 /* Don't compress */
>> #define F2FS_INDEX_FL 0x00001000 /* hash-indexed directory */
>> #define F2FS_DIRSYNC_FL 0x00010000 /* dirsync behaviour (directories only) */
>> +#define F2FS_NOLINEAR_LOOKUP_FL 0x08000000 /* do not use linear lookup */
>> #define F2FS_PROJINHERIT_FL 0x20000000 /* Create with parents projid */
>> #define F2FS_CASEFOLD_FL 0x40000000 /* Casefolded file */
>> #define F2FS_DEVICE_ALIAS_FL 0x80000000 /* File for aliasing a device */
>> @@ -3066,6 +3067,7 @@ static inline void f2fs_change_bit(unsigned int nr, char *addr)
>> #define F2FS_OTHER_FLMASK (F2FS_NODUMP_FL | F2FS_NOATIME_FL)
>>
>> #define IS_DEVICE_ALIASING(inode) (F2FS_I(inode)->i_flags & F2FS_DEVICE_ALIAS_FL)
>> +#define IS_NOLINEAR_LOOKUP(inode) (F2FS_I(inode)->i_flags & F2FS_NOLINEAR_LOOKUP_FL)
>>
>> static inline __u32 f2fs_mask_flags(umode_t mode, __u32 flags)
>> {
>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>> index 014cb7660a9a..1acddc4d11e4 100644
>> --- a/fs/f2fs/file.c
>> +++ b/fs/f2fs/file.c
>> @@ -2062,6 +2062,11 @@ static int f2fs_setflags_common(struct inode *inode, u32 iflags, u32 mask)
>> }
>> }
>>
>> + if ((iflags ^ masked_flags) & F2FS_NOLINEAR_LOOKUP_FLAG) {
>> + if (!S_ISDIR(inode->i_mode) || !IS_CASEFOLDED(inode))
>> + return -EINVAL;
>> + }
>> +
>> fi->i_flags = iflags | (fi->i_flags & ~mask);
>> f2fs_bug_on(F2FS_I_SB(inode), (fi->i_flags & F2FS_COMPR_FL) &&
>> (fi->i_flags & F2FS_NOCOMP_FL));
>> @@ -2093,17 +2098,18 @@ static const struct {
>> u32 iflag;
>> u32 fsflag;
>> } f2fs_fsflags_map[] = {
>> - { F2FS_COMPR_FL, FS_COMPR_FL },
>> - { F2FS_SYNC_FL, FS_SYNC_FL },
>> - { F2FS_IMMUTABLE_FL, FS_IMMUTABLE_FL },
>> - { F2FS_APPEND_FL, FS_APPEND_FL },
>> - { F2FS_NODUMP_FL, FS_NODUMP_FL },
>> - { F2FS_NOATIME_FL, FS_NOATIME_FL },
>> - { F2FS_NOCOMP_FL, FS_NOCOMP_FL },
>> - { F2FS_INDEX_FL, FS_INDEX_FL },
>> - { F2FS_DIRSYNC_FL, FS_DIRSYNC_FL },
>> - { F2FS_PROJINHERIT_FL, FS_PROJINHERIT_FL },
>> - { F2FS_CASEFOLD_FL, FS_CASEFOLD_FL },
>> + { F2FS_COMPR_FL, FS_COMPR_FL },
>> + { F2FS_SYNC_FL, FS_SYNC_FL },
>> + { F2FS_IMMUTABLE_FL, FS_IMMUTABLE_FL },
>> + { F2FS_APPEND_FL, FS_APPEND_FL },
>> + { F2FS_NODUMP_FL, FS_NODUMP_FL },
>> + { F2FS_NOATIME_FL, FS_NOATIME_FL },
>> + { F2FS_NOCOMP_FL, FS_NOCOMP_FL },
>> + { F2FS_INDEX_FL, FS_INDEX_FL },
>> + { F2FS_DIRSYNC_FL, FS_DIRSYNC_FL },
>> + { F2FS_PROJINHERIT_FL, FS_PROJINHERIT_FL },
>> + { F2FS_CASEFOLD_FL, FS_CASEFOLD_FL },
>> + { F2FS_NOLINEAR_LOOKUP_FL, F2FS_NOLINEAR_LOOKUP_FL },
>> };
>>
>> #define F2FS_GETTABLE_FS_FL ( \
>> @@ -2121,7 +2127,8 @@ static const struct {
>> FS_INLINE_DATA_FL | \
>> FS_NOCOW_FL | \
>> FS_VERITY_FL | \
>> - FS_CASEFOLD_FL)
>> + FS_CASEFOLD_FL | \
>> + F2FS_NOLINEAR_LOOKUP_FL)
>>
>> #define F2FS_SETTABLE_FS_FL ( \
>> FS_COMPR_FL | \
>> @@ -2133,7 +2140,8 @@ static const struct {
>> FS_NOCOMP_FL | \
>> FS_DIRSYNC_FL | \
>> FS_PROJINHERIT_FL | \
>> - FS_CASEFOLD_FL)
>> + FS_CASEFOLD_FL | \
>> + F2FS_NOLINEAR_LOOKUP_FL)
>>
>> /* Convert f2fs on-disk i_flags to FS_IOC_{GET,SET}FLAGS flags */
>> static inline u32 f2fs_iflags_to_fsflags(u32 iflags)
>> @@ -3344,6 +3352,8 @@ int f2fs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
>> fsflags |= FS_INLINE_DATA_FL;
>> if (is_inode_flag_set(inode, FI_PIN_FILE))
>> fsflags |= FS_NOCOW_FL;
>> + if (IS_NOLINEAR_LOOKUP(inode))
>> + fsflags |= F2FS_NOLINEAR_LOOKUP_FL;
>>
>> fileattr_fill_flags(fa, fsflags & F2FS_GETTABLE_FS_FL);
>>
>> diff --git a/include/uapi/linux/f2fs.h b/include/uapi/linux/f2fs.h
>> index 795e26258355..a03626fdcf35 100644
>> --- a/include/uapi/linux/f2fs.h
>> +++ b/include/uapi/linux/f2fs.h
>> @@ -104,4 +104,9 @@ struct f2fs_comp_option {
>> __u8 log_cluster_size;
>> };
>>
>> +/* used for FS_IOC_GETFLAGS and FS_IOC_SETFLAGS */
>> +enum {
>> + F2FS_NOLINEAR_LOOKUP_FLAG = 0x08000000,
>> +};
>
> FS_IOC_GETFLAGS and FS_IOC_SETFLAGS are not filesystem-specific, and the
> supported flags are declared in include/uapi/linux/fs.h. You can't just
> randomly give an unused bit a filesystem specific meaning.
Yeah, let me have a try to propose it into vfs.
Thanks,
>
> - Eric