erofs: add LZMA compression support

index a2f38e23004a..f7a3dc13316a 100644
@@ -167,7 +167,7 @@
  * memeq and memzero are not used much and any remotely sane implementation
  * is fast enough. memcpy/memmove speed matters in multi-call mode, but
  * the kernel image is decompressed in single-call mode, in which only
- * memcpy speed can matter and only if there is a lot of uncompressible data
+ * memmove speed can matter and only if there is a lot of uncompressible data
  * (LZMA2 stores uncompressible chunks in uncompressed form). Thus, the
  * functions below should just be kept small; it's probably not worth
  * optimizing for speed.

index 7a6781e3f47b..d548cf0e59fe 100644
@@ -387,7 +387,14 @@ static void dict_uncompressed(struct dictionary *dict, struct xz_buf *b,
 
 		*left -= copy_size;
 
-		memcpy(dict->buf + dict->pos, b->in + b->in_pos, copy_size);
+		/*
+		 * If doing in-place decompression in single-call mode and the
+		 * uncompressed size of the file is larger than the caller
+		 * thought (i.e. it is invalid input!), the buffers below may
+		 * overlap and cause undefined behavior with memcpy().
+		 * With valid inputs memcpy() would be fine here.
+		 */
+		memmove(dict->buf + dict->pos, b->in + b->in_pos, copy_size);
 		dict->pos += copy_size;
 
 		if (dict->full < dict->pos)

@@ -397,7 +404,11 @@ static void dict_uncompressed(struct dictionary *dict, struct xz_buf *b,
 			if (dict->pos == dict->end)
 				dict->pos = 0;
 
-			memcpy(b->out + b->out_pos, b->in + b->in_pos,
+			/*
+			 * Like above but for multi-call mode: use memmove()
+			 * to avoid undefined behavior with invalid input.
+			 */
+			memmove(b->out + b->out_pos, b->in + b->in_pos,
 					copy_size);
 		}
 

@@ -421,6 +432,12 @@ static uint32_t dict_flush(struct dictionary *dict, struct xz_buf *b)
 		if (dict->pos == dict->end)
 			dict->pos = 0;
 
+		/*
+		 * These buffers cannot overlap even if doing in-place
+		 * decompression because in multi-call mode dict->buf
+		 * has been allocated by us in this file; it's not
+		 * provided by the caller like in single-call mode.
+		 */
 		memcpy(b->out + b->out_pos, dict->buf + dict->start,
 				copy_size);
 	}

index fea86deaaa01..683570b93a8c 100644
@@ -402,12 +402,12 @@ static enum xz_ret dec_stream_header(struct xz_dec *s)
 	 * we will accept other check types too, but then the check won't
 	 * be verified and a warning (XZ_UNSUPPORTED_CHECK) will be given.
 	 */
+	if (s->temp.buf[HEADER_MAGIC_SIZE + 1] > XZ_CHECK_MAX)
+		return XZ_OPTIONS_ERROR;
+
 	s->check_type = s->temp.buf[HEADER_MAGIC_SIZE + 1];
 
 #ifdef XZ_DEC_ANY_CHECK
-	if (s->check_type > XZ_CHECK_MAX)
-		return XZ_OPTIONS_ERROR;
-
 	if (s->check_type > XZ_CHECK_CRC32)
 		return XZ_UNSUPPORTED_CHECK;
 #else

index d548cf0e59fe..22b789645ce5 100644
@@ -791,6 +791,7 @@ static void lzma_reset(struct xz_dec_lzma2 *s)
 	s->lzma.rep1 = 0;
 	s->lzma.rep2 = 0;
 	s->lzma.rep3 = 0;
+	s->lzma.len = 0;
 
 	/*
 	 * All probabilities are initialized to the same value. This hack

@@ -1174,8 +1175,6 @@ XZ_EXTERN enum xz_ret xz_dec_lzma2_reset(struct xz_dec_lzma2 *s, uint8_t props)
 		}
 	}
 
-	s->lzma.len = 0;
-
 	s->lzma2.sequence = SEQ_CONTROL;
 	s->lzma2.need_dict_reset = true;
 

index 9884c8440188..7285ca5d56e9 100644
@@ -233,6 +233,112 @@ XZ_EXTERN void xz_dec_reset(struct xz_dec *s);
  */
 XZ_EXTERN void xz_dec_end(struct xz_dec *s);
 
+/*
+ * Decompressor for MicroLZMA, an LZMA variant with a very minimal header.
+ * See xz_dec_microlzma_alloc() below for details.
+ *
+ * These functions aren't used or available in preboot code and thus aren't
+ * marked with XZ_EXTERN. This avoids warnings about static functions that
+ * are never defined.
+ */
+/**
+ * struct xz_dec_microlzma - Opaque type to hold the MicroLZMA decoder state
+ */
+struct xz_dec_microlzma;
+
+/**
+ * xz_dec_microlzma_alloc() - Allocate memory for the MicroLZMA decoder
+ * @mode        XZ_SINGLE or XZ_PREALLOC
+ * @dict_size   LZMA dictionary size. This must be at least 4 KiB and
+ *              at most 3 GiB.
+ *
+ * In contrast to xz_dec_init(), this function only allocates the memory
+ * and remembers the dictionary size. xz_dec_microlzma_reset() must be used
+ * before calling xz_dec_microlzma_run().
+ *
+ * The amount of allocated memory is a little less than 30 KiB with XZ_SINGLE.
+ * With XZ_PREALLOC also a dictionary buffer of dict_size bytes is allocated.
+ *
+ * On success, xz_dec_microlzma_alloc() returns a pointer to
+ * struct xz_dec_microlzma. If memory allocation fails or
+ * dict_size is invalid, NULL is returned.
+ *
+ * The compressed format supported by this decoder is a raw LZMA stream
+ * whose first byte (always 0x00) has been replaced with bitwise-negation
+ * of the LZMA properties (lc/lp/pb) byte. For example, if lc/lp/pb is
+ * 3/0/2, the first byte is 0xA2. This way the first byte can never be 0x00.
+ * Just like with LZMA2, lc + lp <= 4 must be true. The LZMA end-of-stream
+ * marker must not be used. The unused values are reserved for future use.
+ * This MicroLZMA header format was created for use in EROFS but may be used
+ * by others too.
+ */
+extern struct xz_dec_microlzma *xz_dec_microlzma_alloc(enum xz_mode mode,
+						       uint32_t dict_size);
+
+/**
+ * xz_dec_microlzma_reset() - Reset the MicroLZMA decoder state
+ * @s           Decoder state allocated using xz_dec_microlzma_alloc()
+ * @comp_size   Compressed size of the input stream
+ * @uncomp_size Uncompressed size of the input stream. A value smaller
+ *              than the real uncompressed size of the input stream can
+ *              be specified if uncomp_size_is_exact is set to false.
+ *              uncomp_size can never be set to a value larger than the
+ *              expected real uncompressed size because it would eventually
+ *              result in XZ_DATA_ERROR.
+ * @uncomp_size_is_exact  This is an int instead of bool to avoid
+ *              requiring stdbool.h. This should normally be set to true.
+ *              When this is set to false, error detection is weaker.
+ */
+extern void xz_dec_microlzma_reset(struct xz_dec_microlzma *s,
+				   uint32_t comp_size, uint32_t uncomp_size,
+				   int uncomp_size_is_exact);
+
+/**
+ * xz_dec_microlzma_run() - Run the MicroLZMA decoder
+ * @s           Decoder state initialized using xz_dec_microlzma_reset()
+ * @b:          Input and output buffers
+ *
+ * This works similarly to xz_dec_run() with a few important differences.
+ * Only the differences are documented here.
+ *
+ * The only possible return values are XZ_OK, XZ_STREAM_END, and
+ * XZ_DATA_ERROR. This function cannot return XZ_BUF_ERROR: if no progress
+ * is possible due to lack of input data or output space, this function will
+ * keep returning XZ_OK. Thus, the calling code must be written so that it
+ * will eventually provide input and output space matching (or exceeding)
+ * comp_size and uncomp_size arguments given to xz_dec_microlzma_reset().
+ * If the caller cannot do this (for example, if the input file is truncated
+ * or otherwise corrupt), the caller must detect this error by itself to
+ * avoid an infinite loop.
+ *
+ * If the compressed data seems to be corrupt, XZ_DATA_ERROR is returned.
+ * This can happen also when incorrect dictionary, uncompressed, or
+ * compressed sizes have been specified.
+ *
+ * With XZ_PREALLOC only: As an extra feature, b->out may be NULL to skip over
+ * uncompressed data. This way the caller doesn't need to provide a temporary
+ * output buffer for the bytes that will be ignored.
+ *
+ * With XZ_SINGLE only: In contrast to xz_dec_run(), the return value XZ_OK
+ * is also possible and thus XZ_SINGLE is actually a limited multi-call mode.
+ * After XZ_OK the bytes decoded so far may be read from the output buffer.
+ * It is possible to continue decoding but the variables b->out and b->out_pos
+ * MUST NOT be changed by the caller. Increasing the value of b->out_size is
+ * allowed to make more output space available; one doesn't need to provide
+ * space for the whole uncompressed data on the first call. The input buffer
+ * may be changed normally like with XZ_PREALLOC. This way input data can be
+ * provided from non-contiguous memory.
+ */
+extern enum xz_ret xz_dec_microlzma_run(struct xz_dec_microlzma *s,
+					struct xz_buf *b);
+
+/**
+ * xz_dec_microlzma_end() - Free the memory allocated for the decoder state
+ * @s:          Decoder state allocated using xz_dec_microlzma_alloc().
+ *              If s is NULL, this function does nothing.
+ */
+extern void xz_dec_microlzma_end(struct xz_dec_microlzma *s);
+
 /*
  * Standalone build (userspace build or in-kernel build for boot time use)
  * needs a CRC32 implementation. For normal in-kernel use, kernel's own

178 lines not on this page · raw message

index 32eb3c03aede..61098c67a413 100644
@@ -15,8 +15,15 @@ EXPORT_SYMBOL(xz_dec_reset);
 EXPORT_SYMBOL(xz_dec_run);
 EXPORT_SYMBOL(xz_dec_end);
 
+#ifdef CONFIG_XZ_DEC_MICROLZMA
+EXPORT_SYMBOL(xz_dec_microlzma_alloc);
+EXPORT_SYMBOL(xz_dec_microlzma_reset);
+EXPORT_SYMBOL(xz_dec_microlzma_run);
+EXPORT_SYMBOL(xz_dec_microlzma_end);
+#endif
+
 MODULE_DESCRIPTION("XZ decompressor");
-MODULE_VERSION("1.0");
+MODULE_VERSION("1.1");
 MODULE_AUTHOR("Lasse Collin <[email protected]> and Igor Pavlov");
 
 /*

index 09360ebb510e..bf1e94ec7873 100644
@@ -37,6 +37,9 @@
 #		ifdef CONFIG_XZ_DEC_SPARC
 #			define XZ_DEC_SPARC
 #		endif
+#		ifdef CONFIG_XZ_DEC_MICROLZMA
+#			define XZ_DEC_MICROLZMA
+#		endif
 #		define memeq(a, b, size) (memcmp(a, b, size) == 0)
 #		define memzero(buf, size) memset(buf, 0, size)
 #	endif

index f7a3dc13316a..9f4262ee33a5 100644
@@ -20,8 +20,8 @@
  *
  * The worst case for in-place decompression is that the beginning of
  * the file is compressed extremely well, and the rest of the file is
- * uncompressible. Thus, we must look for worst-case expansion when the
- * compressor is encoding uncompressible data.
+ * incompressible. Thus, we must look for worst-case expansion when the
+ * compressor is encoding incompressible data.
  *
  * The structure of the .xz file in case of a compressed kernel is as follows.
  * Sizes (as bytes) of the fields are in parenthesis.

@@ -58,7 +58,7 @@
  * uncompressed size of the payload is in practice never less than the
  * payload size itself. The LZMA2 format would allow uncompressed size
  * to be less than the payload size, but no sane compressor creates such
- * files. LZMA2 supports storing uncompressible data in uncompressed form,
+ * files. LZMA2 supports storing incompressible data in uncompressed form,
  * so there's never a need to create payloads whose uncompressed size is
  * smaller than the compressed size.
  *

@@ -167,8 +167,8 @@
  * memeq and memzero are not used much and any remotely sane implementation
  * is fast enough. memcpy/memmove speed matters in multi-call mode, but
  * the kernel image is decompressed in single-call mode, in which only
- * memmove speed can matter and only if there is a lot of uncompressible data
- * (LZMA2 stores uncompressible chunks in uncompressed form). Thus, the
+ * memmove speed can matter and only if there is a lot of incompressible data
+ * (LZMA2 stores incompressible chunks in uncompressed form). Thus, the
  * functions below should just be kept small; it's probably not worth
  * optimizing for speed.
  */

index 46b186d7eb45..27ce34520e78 100644
@@ -520,7 +520,7 @@ static __always_inline void rc_normalize(struct rc_dec *rc)
  * functions so that the compiler is supposed to be able to more easily avoid
  * an extra branch. In this particular version of the LZMA decoder, this
  * doesn't seem to be a good idea (tested with GCC 3.3.6, 3.4.6, and 4.3.3
- * on x86). Using a non-splitted version results in nicer looking code too.
+ * on x86). Using a non-split version results in nicer looking code too.
  *
  * NOTE: This must return an int. Do not make it return a bool or the speed
  * of the code generated by GCC 3.x decreases 10-15 %. (GCC 4.3 doesn't care,

index a5bc4b1b7813..bceaa2b06b17 100644
@@ -17,13 +17,8 @@
 #endif
 
 struct z_erofs_decompressor {
-	/*
-	 * if destpages have sparsed pages, fill them with bounce pages.
-	 * it also check whether destpages indicate continuous physical memory.
-	 */
-	int (*prepare_destpages)(struct z_erofs_decompress_req *rq,
-				 struct list_head *pagepool);
-	int (*decompress)(struct z_erofs_decompress_req *rq, u8 *out);
+	int (*decompress)(struct z_erofs_decompress_req *rq,
+			  struct list_head *pagepool);
 	char *name;
 };
 

@@ -63,8 +58,12 @@ int z_erofs_load_lz4_config(struct super_block *sb,
 	return erofs_pcpubuf_growsize(sbi->lz4.max_pclusterblks);
 }
 
-static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq,
-					 struct list_head *pagepool)
+/*
+ * Fill all gaps with bounce pages if it's a sparse page list. Also check if
+ * all physical pages are consecutive, which can be seen for moderate CR.
+ */
+static int z_erofs_lz4_prepare_dstpages(struct z_erofs_decompress_req *rq,
+					struct list_head *pagepool)
 {
 	const unsigned int nr =
 		PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;

@@ -119,7 +118,7 @@ static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq,
 	return kaddr ? 1 : 0;
 }
 
-static void *z_erofs_handle_inplace_io(struct z_erofs_decompress_req *rq,
+static void *z_erofs_lz4_handle_inplace_io(struct z_erofs_decompress_req *rq,
 			void *inpage, unsigned int *inputmargin, int *maptype,
 			bool support_0padding)
 {

@@ -189,7 +188,8 @@ static void *z_erofs_handle_inplace_io(struct z_erofs_decompress_req *rq,
 	return src;
 }
 
-static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)
+static int z_erofs_lz4_decompress_mem(struct z_erofs_decompress_req *rq,
+				      u8 *out)
 {
 	unsigned int inputmargin;
 	u8 *headpage, *src;

@@ -216,8 +216,8 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)
 	}
 
 	rq->inputsize -= inputmargin;
-	src = z_erofs_handle_inplace_io(rq, headpage, &inputmargin, &maptype,
-					support_0padding);
+	src = z_erofs_lz4_handle_inplace_io(rq, headpage, &inputmargin,
+					    &maptype, support_0padding);
 	if (IS_ERR(src))
 		return PTR_ERR(src);
 

@@ -257,17 +257,6 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq, u8 *out)
 	return ret;
 }
 
-static struct z_erofs_decompressor decompressors[] = {
-	[Z_EROFS_COMPRESSION_SHIFTED] = {
-		.name = "shifted"
-	},
-	[Z_EROFS_COMPRESSION_LZ4] = {
-		.prepare_destpages = z_erofs_lz4_prepare_destpages,
-		.decompress = z_erofs_lz4_decompress,
-		.name = "lz4"
-	},
-};
-
 static void copy_from_pcpubuf(struct page **out, const char *dst,
 			      unsigned short pageofs_out,
 			      unsigned int outputsize)

@@ -295,12 +284,11 @@ static void copy_from_pcpubuf(struct page **out, const char *dst,
 	}
 }
 
-static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq,
-				      struct list_head *pagepool)
+static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq,
+				  struct list_head *pagepool)
 {
 	const unsigned int nrpages_out =
 		PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
-	const struct z_erofs_decompressor *alg = decompressors + rq->alg;
 	unsigned int dst_maptype;
 	void *dst;
 	int ret;

@@ -325,7 +313,7 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq,
 				return PTR_ERR(dst);
 
 			rq->inplace_io = false;
-			ret = alg->decompress(rq, dst);
+			ret = z_erofs_lz4_decompress_mem(rq, dst);
 			if (!ret)
 				copy_from_pcpubuf(rq->out, dst, rq->pageofs_out,
 						  rq->outputsize);

@@ -336,7 +324,7 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq,
 	}
 
 	/* general decoding path which can be used for all cases */
-	ret = alg->prepare_destpages(rq, pagepool);
+	ret = z_erofs_lz4_prepare_dstpages(rq, pagepool);
 	if (ret < 0)
 		return ret;
 	if (ret) {

@@ -351,7 +339,7 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq,
 	dst_maptype = 2;
 
 dstmap_out:
-	ret = alg->decompress(rq, dst + rq->pageofs_out);
+	ret = z_erofs_lz4_decompress_mem(rq, dst + rq->pageofs_out);
 
 	if (!dst_maptype)
 		kunmap_atomic(dst);

@@ -360,7 +348,7 @@ static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq,
 	return ret;
 }
 
-static int z_erofs_shifted_transform(const struct z_erofs_decompress_req *rq,
+static int z_erofs_shifted_transform(struct z_erofs_decompress_req *rq,
 				     struct list_head *pagepool)
 {
 	const unsigned int nrpages_out =

@@ -399,10 +387,19 @@ static int z_erofs_shifted_transform(const struct z_erofs_decompress_req *rq,
 	return 0;
 }
 
+static struct z_erofs_decompressor decompressors[] = {
+	[Z_EROFS_COMPRESSION_SHIFTED] = {
+		.decompress = z_erofs_shifted_transform,
+		.name = "shifted"
+	},
+	[Z_EROFS_COMPRESSION_LZ4] = {
+		.decompress = z_erofs_lz4_decompress,
+		.name = "lz4"
+	},
+};
+
 int z_erofs_decompress(struct z_erofs_decompress_req *rq,
 		       struct list_head *pagepool)
 {
-	if (rq->alg == Z_EROFS_COMPRESSION_SHIFTED)
-		return z_erofs_shifted_transform(rq, pagepool);
-	return z_erofs_decompress_generic(rq, pagepool);
+	return decompressors[rq->alg].decompress(rq, pagepool);
 }

index ad62d1b4d371..8ea6a9b14962 100644
@@ -20,6 +20,12 @@ struct z_erofs_decompress_req {
 	bool inplace_io, partial_decoding;
 };
 
+struct z_erofs_decompressor {
+	int (*decompress)(struct z_erofs_decompress_req *rq,
+			  struct list_head *pagepool);
+	char *name;
+};
+
 /* some special page->private (unsigned long, see below) */
 #define Z_EROFS_SHORTLIVED_PAGE		(-1UL << 2)
 #define Z_EROFS_PREALLOCATED_PAGE	(-2UL << 2)

@@ -75,7 +81,17 @@ static inline bool z_erofs_put_shortlivedpage(struct list_head *pagepool,
 	return true;
 }
 
+#define MNGD_MAPPING(sbi)	((sbi)->managed_cache->i_mapping)
+static inline bool erofs_page_is_managed(const struct erofs_sb_info *sbi,
+					 struct page *page)
+{
+	return page->mapping == MNGD_MAPPING(sbi);
+}
+
 int z_erofs_decompress(struct z_erofs_decompress_req *rq,
 		       struct list_head *pagepool);
 
+/* prototypes for specific algorithms */
+int z_erofs_lzma_decompress(struct z_erofs_decompress_req *rq,
+			    struct list_head *pagepool);
 #endif

index bceaa2b06b17..0e3b42311158 100644
@@ -16,12 +16,6 @@
 #define LZ4_DECOMPRESS_INPLACE_MARGIN(srcsize)  (((srcsize) >> 8) + 32)
 #endif
 
-struct z_erofs_decompressor {
-	int (*decompress)(struct z_erofs_decompress_req *rq,
-			  struct list_head *pagepool);
-	char *name;
-};
-
 int z_erofs_load_lz4_config(struct super_block *sb,
 			    struct erofs_super_block *dsb,
 			    struct z_erofs_lz4_cfgs *lz4, int size)

@@ -396,6 +390,12 @@ static struct z_erofs_decompressor decompressors[] = {
 		.decompress = z_erofs_lz4_decompress,
 		.name = "lz4"
 	},
+#ifdef CONFIG_EROFS_FS_ZIP_LZMA
+	[Z_EROFS_COMPRESSION_LZMA] = {
+		.decompress = z_erofs_lzma_decompress,
+		.name = "lzma"
+	},
+#endif
 };
 
 int z_erofs_decompress(struct z_erofs_decompress_req *rq,

290 lines not on this page · raw message

index f579c8c78fff..e6337a4a2d13 100644
@@ -249,10 +249,11 @@ struct erofs_inode_chunk_index {
 
 /* available compression algorithm types (for h_algorithmtype) */
 enum {
-	Z_EROFS_COMPRESSION_LZ4	= 0,
+	Z_EROFS_COMPRESSION_LZ4		= 0,
+	Z_EROFS_COMPRESSION_LZMA	= 1,
 	Z_EROFS_COMPRESSION_MAX
 };
-#define Z_EROFS_ALL_COMPR_ALGS		(1 << (Z_EROFS_COMPRESSION_MAX - 1))
+#define Z_EROFS_ALL_COMPR_ALGS		((1 << Z_EROFS_COMPRESSION_MAX) - 1)
 
 /* 14 bytes (+ length field = 16 bytes) */
 struct z_erofs_lz4_cfgs {

@@ -261,6 +262,15 @@ struct z_erofs_lz4_cfgs {
 	u8 reserved[10];
 } __packed;
 
+/* 14 bytes (+ length field = 16 bytes) */
+struct z_erofs_lzma_cfgs {
+	__le32 dict_size;
+	__le16 format;
+	u8 reserved[8];
+} __packed;
+
+#define Z_EROFS_LZMA_MAX_DICT_SIZE	(8 * Z_EROFS_PCLUSTER_MAX_SIZE)
+
 /*
  * bit 0 : COMPACTED_2B indexes (0 - off; 1 - on)
  *  e.g. for 4k logical cluster size,      4B        if compacted 2B is off;

index 7f96265ccbdb..8c04c3ce7af6 100644
@@ -381,6 +381,8 @@ struct erofs_map_blocks {
  * approach instead if possible since it's more metadata lightweight.)
  */
 #define EROFS_GET_BLOCKS_FIEMAP	0x0002
+/* Used to map the whole extent if non-negligible data is requested for LZMA */
+#define EROFS_GET_BLOCKS_READMORE	0x0004
 
 enum {
 	Z_EROFS_COMPRESSION_SHIFTED = Z_EROFS_COMPRESSION_MAX,

@@ -502,6 +504,26 @@ static inline int z_erofs_load_lz4_config(struct super_block *sb,
 }
 #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 */
+
 #define EFSCORRUPTED    EUCLEAN         /* Filesystem is corrupted */
 
 #endif	/* __EROFS_INTERNAL_H */

index 11b88559f8bf..7c2ace97e94e 100644
@@ -225,6 +225,9 @@ static int erofs_load_compr_cfgs(struct super_block *sb,
 		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;

@@ -706,6 +709,10 @@ static int __init erofs_module_init(void)
 	if (err)
 		goto shrinker_err;
 
+	err = z_erofs_lzma_init();
+	if (err)
+		goto lzma_err;
+
 	erofs_pcpubuf_init();
 	err = z_erofs_init_zip_subsystem();
 	if (err)

@@ -720,6 +727,8 @@ static int __init erofs_module_init(void)
 fs_err:
 	z_erofs_exit_zip_subsystem();
 zip_err:
+	z_erofs_lzma_exit();
+lzma_err:
 	erofs_exit_shrinker();
 shrinker_err:
 	kmem_cache_destroy(erofs_inode_cachep);

@@ -730,11 +739,13 @@ static int __init erofs_module_init(void)
 static void __exit erofs_module_exit(void)
 {
 	unregister_filesystem(&erofs_fs_type);
-	z_erofs_exit_zip_subsystem();
-	erofs_exit_shrinker();
 
-	/* Ensure all RCU free inodes are safe before cache is destroyed. */
+	/* Ensure all RCU free inodes / pclusters are safe to be destroyed. */
 	rcu_barrier();
+
+	z_erofs_exit_zip_subsystem();
+	z_erofs_lzma_exit();
+	erofs_exit_shrinker();
 	kmem_cache_destroy(erofs_inode_cachep);
 	erofs_pcpubuf_exit();
 }

index febb018e10a7..159e1dc56be6 100644
@@ -1394,8 +1394,8 @@ static void z_erofs_pcluster_readmore(struct z_erofs_decompress_frontend *f,
 
 	if (backmost) {
 		map->m_la = end;
-		/* TODO: pass in EROFS_GET_BLOCKS_READMORE for LZMA later */
-		err = z_erofs_map_blocks_iter(inode, map, 0);
+		err = z_erofs_map_blocks_iter(inode, map,
+					      EROFS_GET_BLOCKS_READMORE);
 		if (err)
 			return;
 

index 3a008f1b9f78..879df5362777 100644
@@ -94,13 +94,6 @@ struct z_erofs_decompressqueue {
 	} u;
 };
 
-#define MNGD_MAPPING(sbi)	((sbi)->managed_cache->i_mapping)
-static inline bool erofs_page_is_managed(const struct erofs_sb_info *sbi,
-					 struct page *page)
-{
-	return page->mapping == MNGD_MAPPING(sbi);
-}
-
 #define Z_EROFS_ONLINEPAGE_COUNT_BITS   2
 #define Z_EROFS_ONLINEPAGE_COUNT_MASK   ((1 << Z_EROFS_ONLINEPAGE_COUNT_BITS) - 1)
 #define Z_EROFS_ONLINEPAGE_INDEX_SHIFT  (Z_EROFS_ONLINEPAGE_COUNT_BITS)

index 864d9d5474d5..6cc055807e27 100644
@@ -671,7 +671,10 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 	else
 		map->m_algorithmformat = vi->z_algorithmtype[0];
 
-	if (flags & EROFS_GET_BLOCKS_FIEMAP) {
+	if ((flags & EROFS_GET_BLOCKS_FIEMAP) ||
+	    ((flags & EROFS_GET_BLOCKS_READMORE) &&
+	     map->m_algorithmformat == Z_EROFS_COMPRESSION_LZMA &&
+	     map->m_llen >= EROFS_BLKSIZ)) {
 		err = z_erofs_get_extent_decompressedlen(&m);
 		if (!err)
 			map->m_flags |= EROFS_MAP_FULL_MAPPED;