linux-kernel - Re: [PATCH v12 2/8] f2fs: Simplify the handling of cached insensitive names

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Message-ID: <87cysh5wp2.fsf@mailhost.krisman.be>
Date: Tue, 27 Feb 2024 18:11:53 -0500
From: Gabriel Krisman Bertazi <krisman@...e.de>
To: Eugen Hristev <eugen.hristev@...labora.com>
Cc: tytso@....edu,  adilger.kernel@...ger.ca,  linux-ext4@...r.kernel.org,
  jaegeuk@...nel.org,  chao@...nel.org,
  linux-f2fs-devel@...ts.sourceforge.net,  linux-fsdevel@...r.kernel.org,
  linux-kernel@...r.kernel.org,  kernel@...labora.com,
  viro@...iv.linux.org.uk,  brauner@...nel.org,  jack@...e.cz,  Gabriel
 Krisman Bertazi <krisman@...labora.com>,  Eric Biggers
 <ebiggers@...gle.com>
Subject: Re: [PATCH v12 2/8] f2fs: Simplify the handling of cached
 insensitive names

Eugen Hristev <eugen.hristev@...labora.com> writes:

> From: Gabriel Krisman Bertazi <krisman@...labora.com>
>
> Keeping it as qstr avoids the unnecessary conversion in f2fs_match
>
> Reviewed-by: Eric Biggers <ebiggers@...gle.com>
> Signed-off-by: Gabriel Krisman Bertazi <krisman@...labora.com>
> [eugen.hristev@...labora.com: port to 6.8-rc3]
> Signed-off-by: Eugen Hristev <eugen.hristev@...labora.com>
> ---
>  fs/f2fs/dir.c      | 53 ++++++++++++++++++++++++++--------------------
>  fs/f2fs/f2fs.h     | 17 ++++++++++++++-
>  fs/f2fs/recovery.c |  5 +----
>  3 files changed, 47 insertions(+), 28 deletions(-)
>
> diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
> index 3f20d94e12f9..f5b65cf36393 100644
> --- a/fs/f2fs/dir.c
> +++ b/fs/f2fs/dir.c
> @@ -42,35 +42,49 @@ static unsigned int bucket_blocks(unsigned int level)
>  		return 4;
>  }
>  
> +#if IS_ENABLED(CONFIG_UNICODE)
>  /* If @dir is casefolded, initialize @fname->cf_name from @fname->usr_fname. */
>  int f2fs_init_casefolded_name(const struct inode *dir,
>  			      struct f2fs_filename *fname)
>  {
> -#if IS_ENABLED(CONFIG_UNICODE)
>  	struct super_block *sb = dir->i_sb;
> +	unsigned char *buf;
> +	int len;
>  
>  	if (IS_CASEFOLDED(dir) &&
>  	    !is_dot_dotdot(fname->usr_fname->name, fname->usr_fname->len)) {
> -		fname->cf_name.name = f2fs_kmem_cache_alloc(f2fs_cf_name_slab,
> -					GFP_NOFS, false, F2FS_SB(sb));
> -		if (!fname->cf_name.name)
> +		buf = f2fs_kmem_cache_alloc(f2fs_cf_name_slab,
> +					    GFP_NOFS, false, F2FS_SB(sb));
> +		if (!buf)
>  			return -ENOMEM;
> -		fname->cf_name.len = utf8_casefold(sb->s_encoding,
> -						   fname->usr_fname,
> -						   fname->cf_name.name,
> -						   F2FS_NAME_LEN);
> -		if ((int)fname->cf_name.len <= 0) {
> -			kmem_cache_free(f2fs_cf_name_slab, fname->cf_name.name);
> -			fname->cf_name.name = NULL;
> +
> +		len = utf8_casefold(sb->s_encoding, fname->usr_fname,
> +				    buf, F2FS_NAME_LEN);
> +		if (len <= 0) {
> +			kmem_cache_free(f2fs_cf_name_slab, buf);
>  			if (sb_has_strict_encoding(sb))
>  				return -EINVAL;
>  			/* fall back to treating name as opaque byte sequence */
> +			return 0;
>  		}
> +		fname->cf_name.name = buf;
> +		fname->cf_name.len = len;
>  	}
> -#endif
> +
>  	return 0;
>  }
>  
> +void f2fs_free_casefolded_name(struct f2fs_filename *fname)
> +{
> +	unsigned char *buf = (unsigned char *)fname->cf_name.name;
> +
> +	if (buf) {
> +		kmem_cache_free(f2fs_cf_name_slab, buf);
> +		fname->cf_name.name = NULL;
> +	}
> +}

If we use kfree here, we can drop the buf !=NULL check.

> +#endif /* CONFIG_UNICODE */
> +
>  static int __f2fs_setup_filename(const struct inode *dir,
>  				 const struct fscrypt_name *crypt_name,
>  				 struct f2fs_filename *fname)
> @@ -142,12 +156,7 @@ void f2fs_free_filename(struct f2fs_filename *fname)
>  	kfree(fname->crypto_buf.name);
>  	fname->crypto_buf.name = NULL;
>  #endif
> -#if IS_ENABLED(CONFIG_UNICODE)
> -	if (fname->cf_name.name) {
> -		kmem_cache_free(f2fs_cf_name_slab, fname->cf_name.name);
> -		fname->cf_name.name = NULL;
> -	}
> -#endif
> +	f2fs_free_casefolded_name(fname);
>  }
>  
>  static unsigned long dir_block_index(unsigned int level,
> @@ -235,11 +244,9 @@ static inline int f2fs_match_name(const struct inode *dir,
>  	struct fscrypt_name f;
>  
>  #if IS_ENABLED(CONFIG_UNICODE)
> -	if (fname->cf_name.name) {
> -		struct qstr cf = FSTR_TO_QSTR(&fname->cf_name);
> -
> -		return f2fs_match_ci_name(dir, &cf, de_name, de_name_len);
> -	}
> +	if (fname->cf_name.name)
> +		return f2fs_match_ci_name(dir, &fname->cf_name,
> +					  de_name, de_name_len);
>  #endif
>  	f.usr_fname = fname->usr_fname;
>  	f.disk_name = fname->disk_name;
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 84c9fead3ad4..2ff8e52642ec 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -530,7 +530,7 @@ struct f2fs_filename {
>  	 * internal operation where usr_fname is also NULL.  In all these cases
>  	 * we fall back to treating the name as an opaque byte sequence.
>  	 */
> -	struct fscrypt_str cf_name;
> +	struct qstr cf_name;
>  #endif
>  };
>  
> @@ -3533,8 +3533,23 @@ int f2fs_get_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
>  /*
>   * dir.c
>   */
> +unsigned char f2fs_get_de_type(struct f2fs_dir_entry *de);

This is not part of the original patch and doesn't make sense here. It
seems to be included by a bad rebase?


-- 
Gabriel Krisman Bertazi