[PATCH 6.1.y 1/2] erofs: simplify compression configuration parser

Gao Xiang hsiangkao at linux.alibaba.com
Tue Feb 27 14:00:01 AEDT 2024


Hi Yue,

On 2024/2/27 10:22, Yue Hu wrote:
> From: Gao Xiang <hsiangkao at linux.alibaba.com>
> 
> [ Upstream commit efb4fb02cef3ab410b603c8f0e1c67f61d55f542 ]
> 
> Move erofs_load_compr_cfgs() into decompressor.c as well as introduce
> a callback instead of a hard-coded switch for each algorithm for
> simplicity.
> 
> Reviewed-by: Chao Yu <chao at kernel.org>
> Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>
> Link: https://lore.kernel.org/r/20231022130957.11398-1-xiang@kernel.org
> Stable-dep-of: 118a8cf504d7 ("erofs: fix inconsistent per-file compression format")
> Signed-off-by: Yue Hu <huyue2 at coolpad.com>

where is the real fix [patch 2/2]? It's needed to be posted
here too.

Thanks,
Gao Xiang

> ---
>   fs/erofs/compress.h          |  4 ++
>   fs/erofs/decompressor.c      | 60 ++++++++++++++++++++++++++++--
>   fs/erofs/decompressor_lzma.c |  4 +-
>   fs/erofs/internal.h          | 28 ++------------
>   fs/erofs/super.c             | 72 +++++-------------------------------
>   5 files changed, 76 insertions(+), 92 deletions(-)
> 
> diff --git a/fs/erofs/compress.h b/fs/erofs/compress.h
> index 26fa170090b8..c4a3187bdb8f 100644
> --- a/fs/erofs/compress.h
> +++ b/fs/erofs/compress.h
> @@ -21,6 +21,8 @@ struct z_erofs_decompress_req {
>   };
>   
>   struct z_erofs_decompressor {
> +	int (*config)(struct super_block *sb, struct erofs_super_block *dsb,
> +		      void *data, int size);
>   	int (*decompress)(struct z_erofs_decompress_req *rq,
>   			  struct page **pagepool);
>   	char *name;
> @@ -93,6 +95,8 @@ int z_erofs_decompress(struct z_erofs_decompress_req *rq,
>   		       struct page **pagepool);
>   
>   /* prototypes for specific algorithms */
> +int z_erofs_load_lzma_config(struct super_block *sb,
> +			struct erofs_super_block *dsb, void *data, int size);
>   int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,
>   			    struct page **pagepool);
>   #endif
> diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
> index 0cfad74374ca..ae3cfd018d99 100644
> --- a/fs/erofs/decompressor.c
> +++ b/fs/erofs/decompressor.c
> @@ -24,11 +24,11 @@ struct z_erofs_lz4_decompress_ctx {
>   	unsigned int oend;
>   };
>   
> -int z_erofs_load_lz4_config(struct super_block *sb,
> -			    struct erofs_super_block *dsb,
> -			    struct z_erofs_lz4_cfgs *lz4, int size)
> +static int z_erofs_load_lz4_config(struct super_block *sb,
> +			    struct erofs_super_block *dsb, void *data, int size)
>   {
>   	struct erofs_sb_info *sbi = EROFS_SB(sb);
> +	struct z_erofs_lz4_cfgs *lz4 = data;
>   	u16 distance;
>   
>   	if (lz4) {
> @@ -374,17 +374,71 @@ static struct z_erofs_decompressor decompressors[] = {
>   		.name = "interlaced"
>   	},
>   	[Z_EROFS_COMPRESSION_LZ4] = {
> +		.config = z_erofs_load_lz4_config,
>   		.decompress = z_erofs_lz4_decompress,
>   		.name = "lz4"
>   	},
>   #ifdef CONFIG_EROFS_FS_ZIP_LZMA
>   	[Z_EROFS_COMPRESSION_LZMA] = {
> +		.config = z_erofs_load_lzma_config,
>   		.decompress = z_erofs_lzma_decompress,
>   		.name = "lzma"
>   	},
>   #endif
>   };
>   
> +int z_erofs_parse_cfgs(struct super_block *sb, struct erofs_super_block *dsb)
> +{
> +	struct erofs_sb_info *sbi = EROFS_SB(sb);
> +	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
> +	unsigned int algs, alg;
> +	erofs_off_t offset;
> +	int size, ret = 0;
> +
> +	if (!erofs_sb_has_compr_cfgs(sbi)) {
> +		sbi->available_compr_algs = Z_EROFS_COMPRESSION_LZ4;
> +		return z_erofs_load_lz4_config(sb, dsb, NULL, 0);
> +	}
> +
> +	sbi->available_compr_algs = le16_to_cpu(dsb->u1.available_compr_algs);
> +	if (sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS) {
> +		erofs_err(sb, "unidentified algorithms %x, please upgrade kernel",
> +			  sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS);
> +		return -EOPNOTSUPP;
> +	}
> +
> +	offset = EROFS_SUPER_OFFSET + sbi->sb_size;
> +	alg = 0;
> +	for (algs = sbi->available_compr_algs; algs; algs >>= 1, ++alg) {
> +		void *data;
> +
> +		if (!(algs & 1))
> +			continue;
> +
> +		data = erofs_read_metadata(sb, &buf, &offset, &size);
> +		if (IS_ERR(data)) {
> +			ret = PTR_ERR(data);
> +			break;
> +		}
> +
> +		if (alg >= ARRAY_SIZE(decompressors) ||
> +		    !decompressors[alg].config) {
> +			erofs_err(sb, "algorithm %d isn't enabled on this kernel",
> +				  alg);
> +			ret = -EOPNOTSUPP;
> +		} else {
> +			ret = decompressors[alg].config(sb,
> +					dsb, data, size);
> +		}
> +
> +		kfree(data);
> +		if (ret)
> +			break;
> +	}
> +	erofs_put_metabuf(&buf);
> +	return ret;
> +}
> +
>   int z_erofs_decompress(struct z_erofs_decompress_req *rq,
>   		       struct page **pagepool)
>   {
> diff --git a/fs/erofs/decompressor_lzma.c b/fs/erofs/decompressor_lzma.c
> index 49addc345aeb..970464c4b676 100644
> --- a/fs/erofs/decompressor_lzma.c
> +++ b/fs/erofs/decompressor_lzma.c
> @@ -72,10 +72,10 @@ int z_erofs_lzma_init(void)
>   }
>   
>   int z_erofs_load_lzma_config(struct super_block *sb,
> -			     struct erofs_super_block *dsb,
> -			     struct z_erofs_lzma_cfgs *lzma, int size)
> +			struct erofs_super_block *dsb, void *data, int size)
>   {
>   	static DEFINE_MUTEX(lzma_resize_mutex);
> +	struct z_erofs_lzma_cfgs *lzma = data;
>   	unsigned int dict_size, i;
>   	struct z_erofs_lzma *strm, *head = NULL;
>   	int err;
> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
> index d8d09fc3ed65..79a7a5815ea6 100644
> --- a/fs/erofs/internal.h
> +++ b/fs/erofs/internal.h
> @@ -471,6 +471,8 @@ struct erofs_map_dev {
>   
>   /* data.c */
>   extern const struct file_operations erofs_file_fops;
> +void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf,
> +			  erofs_off_t *offset, int *lengthp);
>   void erofs_unmap_metabuf(struct erofs_buf *buf);
>   void erofs_put_metabuf(struct erofs_buf *buf);
>   void *erofs_bread(struct erofs_buf *buf, struct inode *inode,
> @@ -565,9 +567,7 @@ void z_erofs_exit_zip_subsystem(void);
>   int erofs_try_to_free_all_cached_pages(struct erofs_sb_info *sbi,
>   				       struct erofs_workgroup *egrp);
>   int erofs_try_to_free_cached_page(struct page *page);
> -int z_erofs_load_lz4_config(struct super_block *sb,
> -			    struct erofs_super_block *dsb,
> -			    struct z_erofs_lz4_cfgs *lz4, int len);
> +int z_erofs_parse_cfgs(struct super_block *sb, struct erofs_super_block *dsb);
>   #else
>   static inline void erofs_shrinker_register(struct super_block *sb) {}
>   static inline void erofs_shrinker_unregister(struct super_block *sb) {}
> @@ -575,36 +575,14 @@ static inline int erofs_init_shrinker(void) { return 0; }
>   static inline void erofs_exit_shrinker(void) {}
>   static inline int z_erofs_init_zip_subsystem(void) { return 0; }
>   static inline void z_erofs_exit_zip_subsystem(void) {}
> -static inline int z_erofs_load_lz4_config(struct super_block *sb,
> -				  struct erofs_super_block *dsb,
> -				  struct z_erofs_lz4_cfgs *lz4, int len)
> -{
> -	if (lz4 || dsb->u1.lz4_max_distance) {
> -		erofs_err(sb, "lz4 algorithm isn't enabled");
> -		return -EINVAL;
> -	}
> -	return 0;
> -}
>   #endif	/* !CONFIG_EROFS_FS_ZIP */
>   
>   #ifdef CONFIG_EROFS_FS_ZIP_LZMA
>   int z_erofs_lzma_init(void);
>   void z_erofs_lzma_exit(void);
> -int z_erofs_load_lzma_config(struct super_block *sb,
> -			     struct erofs_super_block *dsb,
> -			     struct z_erofs_lzma_cfgs *lzma, int size);
>   #else
>   static inline int z_erofs_lzma_init(void) { return 0; }
>   static inline int z_erofs_lzma_exit(void) { return 0; }
> -static inline int z_erofs_load_lzma_config(struct super_block *sb,
> -			     struct erofs_super_block *dsb,
> -			     struct z_erofs_lzma_cfgs *lzma, int size) {
> -	if (lzma) {
> -		erofs_err(sb, "lzma algorithm isn't enabled");
> -		return -EINVAL;
> -	}
> -	return 0;
> -}
>   #endif	/* !CONFIG_EROFS_FS_ZIP */
>   
>   /* flags for erofs_fscache_register_cookie() */
> diff --git a/fs/erofs/super.c b/fs/erofs/super.c
> index bd8bf8fc2f5d..f2647126cb2f 100644
> --- a/fs/erofs/super.c
> +++ b/fs/erofs/super.c
> @@ -126,8 +126,8 @@ static bool check_layout_compatibility(struct super_block *sb,
>   
>   #ifdef CONFIG_EROFS_FS_ZIP
>   /* read variable-sized metadata, offset will be aligned by 4-byte */
> -static void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf,
> -				 erofs_off_t *offset, int *lengthp)
> +void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf,
> +			  erofs_off_t *offset, int *lengthp)
>   {
>   	u8 *buffer, *ptr;
>   	int len, i, cnt;
> @@ -159,64 +159,15 @@ static void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf,
>   	}
>   	return buffer;
>   }
> -
> -static int erofs_load_compr_cfgs(struct super_block *sb,
> -				 struct erofs_super_block *dsb)
> -{
> -	struct erofs_sb_info *sbi = EROFS_SB(sb);
> -	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
> -	unsigned int algs, alg;
> -	erofs_off_t offset;
> -	int size, ret = 0;
> -
> -	sbi->available_compr_algs = le16_to_cpu(dsb->u1.available_compr_algs);
> -	if (sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS) {
> -		erofs_err(sb, "try to load compressed fs with unsupported algorithms %x",
> -			  sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS);
> -		return -EINVAL;
> -	}
> -
> -	offset = EROFS_SUPER_OFFSET + sbi->sb_size;
> -	alg = 0;
> -	for (algs = sbi->available_compr_algs; algs; algs >>= 1, ++alg) {
> -		void *data;
> -
> -		if (!(algs & 1))
> -			continue;
> -
> -		data = erofs_read_metadata(sb, &buf, &offset, &size);
> -		if (IS_ERR(data)) {
> -			ret = PTR_ERR(data);
> -			break;
> -		}
> -
> -		switch (alg) {
> -		case Z_EROFS_COMPRESSION_LZ4:
> -			ret = z_erofs_load_lz4_config(sb, dsb, data, size);
> -			break;
> -		case Z_EROFS_COMPRESSION_LZMA:
> -			ret = z_erofs_load_lzma_config(sb, dsb, data, size);
> -			break;
> -		default:
> -			DBG_BUGON(1);
> -			ret = -EFAULT;
> -		}
> -		kfree(data);
> -		if (ret)
> -			break;
> -	}
> -	erofs_put_metabuf(&buf);
> -	return ret;
> -}
>   #else
> -static int erofs_load_compr_cfgs(struct super_block *sb,
> -				 struct erofs_super_block *dsb)
> +static int z_erofs_parse_cfgs(struct super_block *sb,
> +			      struct erofs_super_block *dsb)
>   {
> -	if (dsb->u1.available_compr_algs) {
> -		erofs_err(sb, "try to load compressed fs when compression is disabled");
> -		return -EINVAL;
> -	}
> -	return 0;
> +	if (!dsb->u1.available_compr_algs)
> +		return 0;
> +
> +	erofs_err(sb, "compression disabled, unable to mount compressed EROFS");
> +	return -EOPNOTSUPP;
>   }
>   #endif
>   
> @@ -398,10 +349,7 @@ static int erofs_read_superblock(struct super_block *sb)
>   	}
>   
>   	/* parse on-disk compression configurations */
> -	if (erofs_sb_has_compr_cfgs(sbi))
> -		ret = erofs_load_compr_cfgs(sb, dsb);
> -	else
> -		ret = z_erofs_load_lz4_config(sb, dsb, NULL, 0);
> +	ret = z_erofs_parse_cfgs(sb, dsb);
>   	if (ret < 0)
>   		goto out;
>   


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