Re: [PATCH v14 8/9] ext4: Move CONFIG_UNICODE defguards into the code flow

[Gabriel Krisman Bertazi]

Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx> writes:

> From: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
>
> Instead of a bunch of ifdefs, make the unicode built checks part of the
> code flow where possible, as requested by Torvalds.
>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
> [eugen.hristev@xxxxxxxxxxxxx: port to 6.8-rc3]
> Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
> ---
>  fs/ext4/crypto.c | 19 +++----------------
>  fs/ext4/ext4.h   | 33 +++++++++++++++++++++------------
>  fs/ext4/namei.c  | 14 +++++---------
>  fs/ext4/super.c  |  4 +---
>  4 files changed, 30 insertions(+), 40 deletions(-)
>
> diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
> index 7ae0b61258a7..1d2f8b79529c 100644
> --- a/fs/ext4/crypto.c
> +++ b/fs/ext4/crypto.c
> @@ -31,12 +31,7 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
>  
>  	ext4_fname_from_fscrypt_name(fname, &name);
>  
> -#if IS_ENABLED(CONFIG_UNICODE)
> -	err = ext4_fname_setup_ci_filename(dir, iname, fname);
> -	if (err)
> -		ext4_fname_free_filename(fname);
> -#endif
> -	return err;
> +	return ext4_fname_setup_ci_filename(dir, iname, fname);
>  }

Oops. I ended up replying to v10 but it still applies in the latest
version. copying it here for reference:

  This shouldn't remove the error path.  It effectively reintroduces the
  memory leak fixed by commit 7ca4b085f430 ("ext4: fix memory leaks in
  ext4_fname_{setup_filename,prepare_lookup}").

  This patch was only about inlining the codeguards, so it shouldn't be
  changing the logic.

>  int ext4_fname_prepare_lookup(struct inode *dir, struct dentry *dentry,
> @@ -51,12 +46,7 @@ int ext4_fname_prepare_lookup(struct inode *dir, struct dentry *dentry,
>  
>  	ext4_fname_from_fscrypt_name(fname, &name);
>  
> -#if IS_ENABLED(CONFIG_UNICODE)
> -	err = ext4_fname_setup_ci_filename(dir, &dentry->d_name, fname);
> -	if (err)
> -		ext4_fname_free_filename(fname);
> -#endif
> -	return err;
> +	return ext4_fname_setup_ci_filename(dir, &dentry->d_name, fname);
>  }
>  
>  void ext4_fname_free_filename(struct ext4_filename *fname)
> @@ -70,10 +60,7 @@ void ext4_fname_free_filename(struct ext4_filename *fname)
>  	fname->usr_fname = NULL;
>  	fname->disk_name.name = NULL;
>  
> -#if IS_ENABLED(CONFIG_UNICODE)
> -	kfree(fname->cf_name.name);
> -	fname->cf_name.name = NULL;
> -#endif
> +	ext4_fname_free_ci_filename(fname);
>  }
>  
>  static bool uuid_is_zero(__u8 u[16])
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 4061d11b9763..c68f48f706cd 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -2740,8 +2740,25 @@ ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
>  
>  #if IS_ENABLED(CONFIG_UNICODE)
>  extern int ext4_fname_setup_ci_filename(struct inode *dir,
> -					 const struct qstr *iname,
> -					 struct ext4_filename *fname);
> +					const struct qstr *iname,
> +					struct ext4_filename *fname);
> +
> +static inline void ext4_fname_free_ci_filename(struct ext4_filename *fname)
> +{
> +	kfree(fname->cf_name.name);
> +	fname->cf_name.name = NULL;
> +}
> +#else
> +static inline int ext4_fname_setup_ci_filename(struct inode *dir,
> +					       const struct qstr *iname,
> +					       struct ext4_filename *fname)
> +{
> +	return 0;
> +}
> +
> +static inline void ext4_fname_free_ci_filename(struct ext4_filename *fname)
> +{
> +}
>  #endif
>  
>  /* ext4 encryption related stuff goes here crypto.c */
> @@ -2764,16 +2781,11 @@ static inline int ext4_fname_setup_filename(struct inode *dir,
>  					    int lookup,
>  					    struct ext4_filename *fname)
>  {
> -	int err = 0;
>  	fname->usr_fname = iname;
>  	fname->disk_name.name = (unsigned char *) iname->name;
>  	fname->disk_name.len = iname->len;
>  
> -#if IS_ENABLED(CONFIG_UNICODE)
> -	err = ext4_fname_setup_ci_filename(dir, iname, fname);
> -#endif
> -
> -	return err;
> +	return ext4_fname_setup_ci_filename(dir, iname, fname);
>  }
>  
>  static inline int ext4_fname_prepare_lookup(struct inode *dir,
> @@ -2785,10 +2797,7 @@ static inline int ext4_fname_prepare_lookup(struct inode *dir,
>  
>  static inline void ext4_fname_free_filename(struct ext4_filename *fname)
>  {
> -#if IS_ENABLED(CONFIG_UNICODE)
> -	kfree(fname->cf_name.name);
> -	fname->cf_name.name = NULL;
> -#endif
> +	ext4_fname_free_ci_filename(fname);
>  }
>  
>  static inline int ext4_ioctl_get_encryption_pwsalt(struct file *filp,
> diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
> index 3268cf45d9db..a5d9e5b01015 100644
> --- a/fs/ext4/namei.c
> +++ b/fs/ext4/namei.c
> @@ -1834,8 +1834,7 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi
>  		}
>  	}
>  
> -#if IS_ENABLED(CONFIG_UNICODE)
> -	if (!inode && IS_CASEFOLDED(dir)) {
> +	if (IS_ENABLED(CONFIG_UNICODE) && !inode && IS_CASEFOLDED(dir)) {
>  		/* Eventually we want to call d_add_ci(dentry, NULL)
>  		 * for negative dentries in the encoding case as
>  		 * well.  For now, prevent the negative dentry
> @@ -1843,7 +1842,7 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi
>  		 */
>  		return NULL;
>  	}
> -#endif
> +
>  	return d_splice_alias(inode, dentry);
>  }
>  
> @@ -3173,16 +3172,14 @@ static int ext4_rmdir(struct inode *dir, struct dentry *dentry)
>  	ext4_fc_track_unlink(handle, dentry);
>  	retval = ext4_mark_inode_dirty(handle, dir);
>  
> -#if IS_ENABLED(CONFIG_UNICODE)
>  	/* VFS negative dentries are incompatible with Encoding and
>  	 * Case-insensitiveness. Eventually we'll want avoid
>  	 * invalidating the dentries here, alongside with returning the
>  	 * negative dentries at ext4_lookup(), when it is better
>  	 * supported by the VFS for the CI case.
>  	 */
> -	if (IS_CASEFOLDED(dir))
> +	if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
>  		d_invalidate(dentry);
> -#endif
>  
>  end_rmdir:
>  	brelse(bh);
> @@ -3284,16 +3281,15 @@ static int ext4_unlink(struct inode *dir, struct dentry *dentry)
>  		goto out_trace;
>  
>  	retval = __ext4_unlink(dir, &dentry->d_name, d_inode(dentry), dentry);
> -#if IS_ENABLED(CONFIG_UNICODE)
> +
>  	/* VFS negative dentries are incompatible with Encoding and
>  	 * Case-insensitiveness. Eventually we'll want avoid
>  	 * invalidating the dentries here, alongside with returning the
>  	 * negative dentries at ext4_lookup(), when it is  better
>  	 * supported by the VFS for the CI case.
>  	 */
> -	if (IS_CASEFOLDED(dir))
> +	if (IS_ENABLED(CONFIG_UNICODE) && IS_CASEFOLDED(dir))
>  		d_invalidate(dentry);
> -#endif
>  
>  out_trace:
>  	trace_ext4_unlink_exit(dentry, retval);
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 215b4614eb15..179083728b4b 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -3609,14 +3609,12 @@ int ext4_feature_set_ok(struct super_block *sb, int readonly)
>  		return 0;
>  	}
>  
> -#if !IS_ENABLED(CONFIG_UNICODE)
> -	if (ext4_has_feature_casefold(sb)) {
> +	if (!IS_ENABLED(CONFIG_UNICODE) && ext4_has_feature_casefold(sb)) {
>  		ext4_msg(sb, KERN_ERR,
>  			 "Filesystem with casefold feature cannot be "
>  			 "mounted without CONFIG_UNICODE");
>  		return 0;
>  	}
> -#endif
>  
>  	if (readonly)
>  		return 1;

-- 
Gabriel Krisman Bertazi