erofs: simplify compression configuration parser

[ 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@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: Sasha Levin <sashal@kernel.org>

diff --git a/fs/erofs/compress.h b/fs/erofs/compress.h
index 349c331..279933e 100644 (file)
--- 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;
@@ -92,6 +94,10 @@ int z_erofs_fixup_insize(struct z_erofs_decompress_req *rq, const char *padbuf,
 extern const struct z_erofs_decompressor erofs_decompressors[];
 
 /* 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_load_deflate_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);
 int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,

diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index 332ec5f..e75edc8 100644 (file)
--- 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) {
@@ -370,19 +370,75 @@ const struct z_erofs_decompressor erofs_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
 #ifdef CONFIG_EROFS_FS_ZIP_DEFLATE
        [Z_EROFS_COMPRESSION_DEFLATE] = {
+               .config = z_erofs_load_deflate_config,
                .decompress = z_erofs_deflate_decompress,
                .name = "deflate"
        },
 #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;
+       }
+
+       erofs_init_metabuf(&buf, sb);
+       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(erofs_decompressors) ||
+                   !erofs_decompressors[alg].config) {
+                       erofs_err(sb, "algorithm %d isn't enabled on this kernel",
+                                 alg);
+                       ret = -EOPNOTSUPP;
+               } else {
+                       ret = erofs_decompressors[alg].config(sb,
+                                       dsb, data, size);
+               }
+
+               kfree(data);
+               if (ret)
+                       break;
+       }
+       erofs_put_metabuf(&buf);
+       return ret;
+}

diff --git a/fs/erofs/decompressor_deflate.c b/fs/erofs/decompressor_deflate.c
index 19e5bde..0e1946a 100644 (file)
--- a/fs/erofs/decompressor_deflate.c
+++ b/fs/erofs/decompressor_deflate.c
@@ -77,9 +77,10 @@ out_failed:
 }
 
 int z_erofs_load_deflate_config(struct super_block *sb,
-                               struct erofs_super_block *dsb,
-                               struct z_erofs_deflate_cfgs *dfl, int size)
+                       struct erofs_super_block *dsb, void *data, int size)
 {
+       struct z_erofs_deflate_cfgs *dfl = data;
+
        if (!dfl || size < sizeof(struct z_erofs_deflate_cfgs)) {
                erofs_err(sb, "invalid deflate cfgs, size=%u", size);
                return -EINVAL;

diff --git a/fs/erofs/decompressor_lzma.c b/fs/erofs/decompressor_lzma.c
index dee10d2..ba4ec73 100644 (file)
--- a/fs/erofs/decompressor_lzma.c
+++ b/fs/erofs/decompressor_lzma.c
@@ -72,10 +72,10 @@ int __init 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 4ff88d0..d8de613 100644 (file)
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -469,9 +469,6 @@ int __init z_erofs_init_zip_subsystem(void);
 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 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_map_blocks_iter(struct inode *inode, struct erofs_map_blocks *map,
                            int flags);
 void *erofs_get_pcpubuf(unsigned int requiredpages);
@@ -480,6 +477,7 @@ int erofs_pcpubuf_growsize(unsigned int nrpages);
 void __init erofs_pcpubuf_init(void);
 void erofs_pcpubuf_exit(void);
 int erofs_init_managed_cache(struct super_block *sb);
+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) {}
@@ -487,16 +485,6 @@ 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;
-}
 static inline void erofs_pcpubuf_init(void) {}
 static inline void erofs_pcpubuf_exit(void) {}
 static inline int erofs_init_managed_cache(struct super_block *sb) { return 0; }
@@ -505,41 +493,17 @@ static inline int erofs_init_managed_cache(struct super_block *sb) { return 0; }
 #ifdef CONFIG_EROFS_FS_ZIP_LZMA
 int __init 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_LZMA */
 
 #ifdef CONFIG_EROFS_FS_ZIP_DEFLATE
 int __init z_erofs_deflate_init(void);
 void z_erofs_deflate_exit(void);
-int z_erofs_load_deflate_config(struct super_block *sb,
-                               struct erofs_super_block *dsb,
-                               struct z_erofs_deflate_cfgs *dfl, int size);
 #else
 static inline int z_erofs_deflate_init(void) { return 0; }
 static inline int z_erofs_deflate_exit(void) { return 0; }
-static inline int z_erofs_load_deflate_config(struct super_block *sb,
-                       struct erofs_super_block *dsb,
-                       struct z_erofs_deflate_cfgs *dfl, int size) {
-       if (dfl) {
-               erofs_err(sb, "deflate algorithm isn't enabled");
-               return -EINVAL;
-       }
-       return 0;
-}
 #endif /* !CONFIG_EROFS_FS_ZIP_DEFLATE */
 
 #ifdef CONFIG_EROFS_FS_ONDEMAND

diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 3700af9..cc44fb2 100644 (file)
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -156,68 +156,15 @@ void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf,
        return buffer;
 }
 
-#ifdef CONFIG_EROFS_FS_ZIP
-static int erofs_load_compr_cfgs(struct super_block *sb,
-                                struct erofs_super_block *dsb)
+#ifndef CONFIG_EROFS_FS_ZIP
+static 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;
-
-       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;
-       }
-
-       erofs_init_metabuf(&buf, sb);
-       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 (!dsb->u1.available_compr_algs)
+               return 0;
 
-               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;
-               case Z_EROFS_COMPRESSION_DEFLATE:
-                       ret = z_erofs_load_deflate_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)
-{
-       if (dsb->u1.available_compr_algs) {
-               erofs_err(sb, "try to load compressed fs when compression is disabled");
-               return -EINVAL;
-       }
-       return 0;
+       erofs_err(sb, "compression disabled, unable to mount compressed EROFS");
+       return -EOPNOTSUPP;
 }
 #endif
 
@@ -406,10 +353,7 @@ 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;