[PATCH 6.1 185/195] erofs: simplify compression configuration parser

Greg Kroah-Hartman
2024-02-27T14:20:52Z

From: Gao Xiang <hsiangkao@linux.alibaba.com>

commit efb4fb02cef3ab410b603c8f0e1c67f61d55f542 upstream.

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@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@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@coolpad.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
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(-)

--- 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_de
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
--- 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 decom
.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)
{
--- 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;
--- 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(vo
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() */
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -126,8 +126,8 @@ static bool check_layout_compatibility(s

#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
}
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
}

/* 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;