[PATCH RESEND 01/10] staging: erofs: cleanup z_erofs_vle_work_{lookup, register}

[PATCH RESEND 01/10] staging: erofs: cleanup z_erofs_vle_work_{lookup, register}

[Gao Xiang]

This patch introduces 'struct z_erofs_vle_work_finder' to clean up
arguments of z_erofs_vle_work_lookup and z_erofs_vle_work_register.

Reviewed-by: Chao Yu <yuchao0 at huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
---
RESEND:
 - add `Reviewed-by: Chao Yu <yuchao0 at huawei.com>'
 - no logic change

 drivers/staging/erofs/unzip_vle.c | 89 +++++++++++++++++++++------------------
 1 file changed, 47 insertions(+), 42 deletions(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index b2e05e2..5032b3b 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -271,36 +271,42 @@ static inline bool try_to_claim_workgroup(
 	return true;	/* lucky, I am the followee :) */
 }
 
+struct z_erofs_vle_work_finder {
+	struct super_block *sb;
+	pgoff_t idx;
+	unsigned pageofs;
+
+	struct z_erofs_vle_workgroup **grp_ret;
+	enum z_erofs_vle_work_role *role;
+	z_erofs_vle_owned_workgrp_t *owned_head;
+	bool *hosted;
+};
+
 static struct z_erofs_vle_work *
-z_erofs_vle_work_lookup(struct super_block *sb,
-			pgoff_t idx, unsigned pageofs,
-			struct z_erofs_vle_workgroup **grp_ret,
-			enum z_erofs_vle_work_role *role,
-			z_erofs_vle_owned_workgrp_t *owned_head,
-			bool *hosted)
+z_erofs_vle_work_lookup(const struct z_erofs_vle_work_finder *f)
 {
 	bool tag, primary;
 	struct erofs_workgroup *egrp;
 	struct z_erofs_vle_workgroup *grp;
 	struct z_erofs_vle_work *work;
 
-	egrp = erofs_find_workgroup(sb, idx, &tag);
+	egrp = erofs_find_workgroup(f->sb, f->idx, &tag);
 	if (egrp == NULL) {
-		*grp_ret = NULL;
+		*f->grp_ret = NULL;
 		return NULL;
 	}
 
-	*grp_ret = grp = container_of(egrp,
-		struct z_erofs_vle_workgroup, obj);
+	grp = container_of(egrp, struct z_erofs_vle_workgroup, obj);
+	*f->grp_ret = grp;
 
 #ifndef CONFIG_EROFS_FS_ZIP_MULTIREF
-	work = z_erofs_vle_grab_work(grp, pageofs);
+	work = z_erofs_vle_grab_work(grp, f->pageofs);
 	primary = true;
 #else
 	BUG();
 #endif
 
-	DBG_BUGON(work->pageofs != pageofs);
+	DBG_BUGON(work->pageofs != f->pageofs);
 
 	/*
 	 * lock must be taken first to avoid grp->next == NIL between
@@ -340,29 +346,24 @@ static inline bool try_to_claim_workgroup(
 	 */
 	mutex_lock(&work->lock);
 
-	*hosted = false;
+	*f->hosted = false;
 	if (!primary)
-		*role = Z_EROFS_VLE_WORK_SECONDARY;
+		*f->role = Z_EROFS_VLE_WORK_SECONDARY;
 	/* claim the workgroup if possible */
-	else if (try_to_claim_workgroup(grp, owned_head, hosted))
-		*role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED;
+	else if (try_to_claim_workgroup(grp, f->owned_head, f->hosted))
+		*f->role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED;
 	else
-		*role = Z_EROFS_VLE_WORK_PRIMARY;
+		*f->role = Z_EROFS_VLE_WORK_PRIMARY;
 
 	return work;
 }
 
 static struct z_erofs_vle_work *
-z_erofs_vle_work_register(struct super_block *sb,
-			  struct z_erofs_vle_workgroup **grp_ret,
-			  struct erofs_map_blocks *map,
-			  pgoff_t index, unsigned pageofs,
-			  enum z_erofs_vle_work_role *role,
-			  z_erofs_vle_owned_workgrp_t *owned_head,
-			  bool *hosted)
+z_erofs_vle_work_register(const struct z_erofs_vle_work_finder *f,
+			  struct erofs_map_blocks *map)
 {
-	bool newgrp = false;
-	struct z_erofs_vle_workgroup *grp = *grp_ret;
+	bool gnew = false;
+	struct z_erofs_vle_workgroup *grp = *f->grp_ret;
 	struct z_erofs_vle_work *work;
 
 #ifndef CONFIG_EROFS_FS_ZIP_MULTIREF
@@ -376,7 +377,7 @@ static inline bool try_to_claim_workgroup(
 	if (unlikely(grp == NULL))
 		return ERR_PTR(-ENOMEM);
 
-	grp->obj.index = index;
+	grp->obj.index = f->idx;
 	grp->llen = map->m_llen;
 
 	z_erofs_vle_set_workgrp_fmt(grp,
@@ -386,13 +387,13 @@ static inline bool try_to_claim_workgroup(
 	atomic_set(&grp->obj.refcount, 1);
 
 	/* new workgrps have been claimed as type 1 */
-	WRITE_ONCE(grp->next, *owned_head);
+	WRITE_ONCE(grp->next, *f->owned_head);
 	/* primary and followed work for all new workgrps */
-	*role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED;
+	*f->role = Z_EROFS_VLE_WORK_PRIMARY_FOLLOWED;
 	/* it should be submitted by ourselves */
-	*hosted = true;
+	*f->hosted = true;
 
-	newgrp = true;
+	gnew = true;
 #ifdef CONFIG_EROFS_FS_ZIP_MULTIREF
 skip:
 	/* currently unimplemented */
@@ -400,12 +401,12 @@ static inline bool try_to_claim_workgroup(
 #else
 	work = z_erofs_vle_grab_primary_work(grp);
 #endif
-	work->pageofs = pageofs;
+	work->pageofs = f->pageofs;
 
 	mutex_init(&work->lock);
 
-	if (newgrp) {
-		int err = erofs_register_workgroup(sb, &grp->obj, 0);
+	if (gnew) {
+		int err = erofs_register_workgroup(f->sb, &grp->obj, 0);
 
 		if (err) {
 			kmem_cache_free(z_erofs_workgroup_cachep, grp);
@@ -413,7 +414,7 @@ static inline bool try_to_claim_workgroup(
 		}
 	}
 
-	*owned_head = *grp_ret = grp;
+	*f->owned_head = *f->grp_ret = grp;
 
 	mutex_lock(&work->lock);
 	return work;
@@ -440,9 +441,16 @@ static int z_erofs_vle_work_iter_begin(struct z_erofs_vle_work_builder *builder,
 				       z_erofs_vle_owned_workgrp_t *owned_head)
 {
 	const unsigned clusterpages = erofs_clusterpages(EROFS_SB(sb));
-	const erofs_blk_t index = erofs_blknr(map->m_pa);
-	const unsigned pageofs = map->m_la & ~PAGE_MASK;
 	struct z_erofs_vle_workgroup *grp;
+	const struct z_erofs_vle_work_finder finder = {
+		.sb = sb,
+		.idx = erofs_blknr(map->m_pa),
+		.pageofs = map->m_la & ~PAGE_MASK,
+		.grp_ret = &grp,
+		.role = &builder->role,
+		.owned_head = owned_head,
+		.hosted = &builder->hosted
+	};
 	struct z_erofs_vle_work *work;
 
 	DBG_BUGON(builder->work != NULL);
@@ -454,16 +462,13 @@ static int z_erofs_vle_work_iter_begin(struct z_erofs_vle_work_builder *builder,
 	DBG_BUGON(erofs_blkoff(map->m_pa));
 
 repeat:
-	work = z_erofs_vle_work_lookup(sb, index,
-		pageofs, &grp, &builder->role, owned_head, &builder->hosted);
+	work = z_erofs_vle_work_lookup(&finder);
 	if (work != NULL) {
 		__update_workgrp_llen(grp, map->m_llen);
 		goto got_it;
 	}
 
-	work = z_erofs_vle_work_register(sb, &grp, map, index, pageofs,
-		&builder->role, owned_head, &builder->hosted);
-
+	work = z_erofs_vle_work_register(&finder, map);
 	if (unlikely(work == ERR_PTR(-EAGAIN)))
 		goto repeat;
 
-- 
1.9.1

[PATCH RESEND 02/10] staging: erofs: rearrange vle clustertype definitions

[Gao Xiang]

This patch moves vle clustertype definitions to erofs_fs.h
since they are part of on-disk format.

It also adds compile time check for Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS

Reviewed-by: Chao Yu <yuchao0 at huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
---
RESEND:
 - add `Reviewed-by: Chao Yu <yuchao0 at huawei.com>'
 - no logic change
 
 drivers/staging/erofs/erofs_fs.h  | 11 +++++++++++
 drivers/staging/erofs/unzip_vle.c |  8 --------
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/erofs/erofs_fs.h b/drivers/staging/erofs/erofs_fs.h
index 2f8e2bf..d4bffa2 100644
--- a/drivers/staging/erofs/erofs_fs.h
+++ b/drivers/staging/erofs/erofs_fs.h
@@ -202,6 +202,14 @@ struct erofs_extent_header {
  *        di_u.delta[1] = distance to its corresponding tail cluster
  *                (di_advise could be 0, 1 or 2)
  */
+enum {
+	Z_EROFS_VLE_CLUSTER_TYPE_PLAIN,
+	Z_EROFS_VLE_CLUSTER_TYPE_HEAD,
+	Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD,
+	Z_EROFS_VLE_CLUSTER_TYPE_RESERVED,
+	Z_EROFS_VLE_CLUSTER_TYPE_MAX
+};
+
 #define Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS        2
 #define Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT         0
 
@@ -260,6 +268,9 @@ static inline void erofs_check_ondisk_layout_definitions(void)
 	BUILD_BUG_ON(sizeof(struct erofs_extent_header) != 16);
 	BUILD_BUG_ON(sizeof(struct z_erofs_vle_decompressed_index) != 8);
 	BUILD_BUG_ON(sizeof(struct erofs_dirent) != 12);
+
+	BUILD_BUG_ON(BIT(Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) <
+		     Z_EROFS_VLE_CLUSTER_TYPE_MAX - 1);
 }
 
 #endif
diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 5032b3b..f597f07 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -1416,14 +1416,6 @@ static int z_erofs_vle_normalaccess_readpages(
 #define __vle_cluster_type(advise) __vle_cluster_advise(advise, \
 	Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT, Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS)
 
-enum {
-	Z_EROFS_VLE_CLUSTER_TYPE_PLAIN,
-	Z_EROFS_VLE_CLUSTER_TYPE_HEAD,
-	Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD,
-	Z_EROFS_VLE_CLUSTER_TYPE_RESERVED,
-	Z_EROFS_VLE_CLUSTER_TYPE_MAX
-};
-
 #define vle_cluster_type(di)	\
 	__vle_cluster_type((di)->di_advise)
 
-- 
1.9.1

[PATCH v2 03/10] staging: erofs: fix vle_decompressed_index_clusterofs

[Gao Xiang]

This patch adds error handing code, and fixes a missing
endian conversion in vle_decompressed_index_clusterofs.

Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
---
change log v2:
 - change the commit message;
 - I personally think this patch is clear enough, therefore I don't
   spilt into more small patches.

 drivers/staging/erofs/unzip_vle.c | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index f597f07..ae99b68 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -1419,24 +1419,24 @@ static int z_erofs_vle_normalaccess_readpages(
 #define vle_cluster_type(di)	\
 	__vle_cluster_type((di)->di_advise)
 
-static inline unsigned
-vle_compressed_index_clusterofs(unsigned clustersize,
-	struct z_erofs_vle_decompressed_index *di)
+static inline int
+vle_decompressed_index_clusterofs(unsigned int *clusterofs,
+				  unsigned int clustersize,
+				  struct z_erofs_vle_decompressed_index *di)
 {
-	debugln("%s, vle=%pK, advise=%x (type %u), clusterofs=%x blkaddr=%x",
-		__func__, di, di->di_advise, vle_cluster_type(di),
-		di->di_clusterofs, di->di_u.blkaddr);
-
 	switch (vle_cluster_type(di)) {
 	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
+		*clusterofs = clustersize;
 		break;
 	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
 	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
-		return di->di_clusterofs;
+		*clusterofs = le16_to_cpu(di->di_clusterofs);
+		break;
 	default:
-		BUG_ON(1);
+		DBG_BUGON(1);
+		return -EIO;
 	}
-	return clustersize;
+	return 0;
 }
 
 static inline erofs_blk_t
@@ -1581,7 +1581,11 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 	debugln("%s, lcn %u e_blkaddr %u e_blkoff %u", __func__, lcn,
 		e_blkaddr, vle_extent_blkoff(inode, lcn));
 
-	logical_cluster_ofs = vle_compressed_index_clusterofs(clustersize, di);
+	err = vle_decompressed_index_clusterofs(&logical_cluster_ofs,
+						clustersize, di);
+	if (unlikely(err))
+		goto unmap_out;
+
 	if (!initial) {
 		/* [walking mode] 'map' has been already initialized */
 		map->m_llen += logical_cluster_ofs;
-- 
1.9.1

[PATCH v3 04/10] staging: erofs: fix a missing endian conversion

[Gao Xiang]

This patch fixes a missing endian conversion in
vle_get_logical_extent_head.

Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
---
change log v3:
 - spilt into small patches at Chao's suggestion.

 drivers/staging/erofs/unzip_vle.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index ae99b68..c59f4c6 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -1488,6 +1488,7 @@ static erofs_off_t vle_get_logical_extent_head(
 	struct super_block *const sb = inode->i_sb;
 	const unsigned int clusterbits = EROFS_SB(sb)->clusterbits;
 	const unsigned int clustersize = 1 << clusterbits;
+	unsigned delta0;
 
 	if (page->index != blkaddr) {
 		kunmap_atomic(*kaddr_iter);
@@ -1502,12 +1503,13 @@ static erofs_off_t vle_get_logical_extent_head(
 	di = *kaddr_iter + vle_extent_blkoff(inode, lcn);
 	switch (vle_cluster_type(di)) {
 	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
-		BUG_ON(!di->di_u.delta[0]);
-		BUG_ON(lcn < di->di_u.delta[0]);
+		delta0 = le16_to_cpu(di->di_u.delta[0]);
+		DBG_BUGON(!delta0);
+		DBG_BUGON(lcn < delta0);
 
 		ofs = vle_get_logical_extent_head(inode,
 			page_iter, kaddr_iter,
-			lcn - di->di_u.delta[0], pcn, flags);
+			lcn - delta0, pcn, flags);
 		break;
 	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
 		*flags ^= EROFS_MAP_ZIPPED;
-- 
1.9.1

[PREVIEW] [PATCH v3 05/10] staging: erofs: fix integer overflow on 32-bit platform

[Gao Xiang]

This patch fixes integer overflow on multiplication
of 32-bit lcn in z_erofs_map_blocks_iter.

Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
---
change log v3:
 - spilt into small patches at Chao's suggestion.

 drivers/staging/erofs/unzip_vle.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index c59f4c6..6404e02 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -1515,7 +1515,7 @@ static erofs_off_t vle_get_logical_extent_head(
 		*flags ^= EROFS_MAP_ZIPPED;
 	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
 		/* clustersize should be a power of two */
-		ofs = ((unsigned long long)lcn << clusterbits) +
+		ofs = ((u64)lcn << clusterbits) +
 			(le16_to_cpu(di->di_clusterofs) & (clustersize - 1));
 		*pcn = le32_to_cpu(di->di_u.blkaddr);
 		break;
@@ -1597,7 +1597,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 	/* by default, compressed */
 	map->m_flags |= EROFS_MAP_ZIPPED;
 
-	end = (u64)(lcn + 1) * clustersize;
+	end = ((u64)lcn + 1) * clustersize;
 
 	cluster_type = vle_cluster_type(di);
 
@@ -1613,7 +1613,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 		}
 
 		if (ofs_rem > logical_cluster_ofs) {
-			ofs = lcn * clustersize | logical_cluster_ofs;
+			ofs = (u64)lcn * clustersize | logical_cluster_ofs;
 			pcn = le32_to_cpu(di->di_u.blkaddr);
 			break;
 		}
@@ -1625,7 +1625,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 			err = -EIO;
 			goto unmap_out;
 		}
-		end = (lcn-- * clustersize) | logical_cluster_ofs;
+		end = ((u64)lcn-- * clustersize) | logical_cluster_ofs;
 		/* fallthrough */
 	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
 		/* get the correspoinding first chunk */
-- 
1.9.1

[PREVIEW] [PATCH v3 06/10] staging: erofs: fix compression mapping beyond EOF

[Gao Xiang]

Logical address of EOF LTP mapping should start at
`inode->i_size' rather than `inode->i_size - 1' to
`m_la(in) + 1 - inode->i_size', fix it.

Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
---
change log v3:
 - spilt into small patches at Chao's suggestion.

 drivers/staging/erofs/unzip_vle.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 6404e02..f81b2a6 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -1550,7 +1550,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 	if (unlikely(map->m_la >= inode->i_size)) {
 		BUG_ON(!initial);
 		map->m_llen = map->m_la + 1 - inode->i_size;
-		map->m_la = inode->i_size - 1;
+		map->m_la = inode->i_size;
 		map->m_flags = 0;
 		goto out;
 	}
-- 
1.9.1

[PREVIEW] [PATCH v3 07/10] staging: erofs: clean up z_erofs_map_blocks_iter

[Gao Xiang]

This patch mainly introduces `vle_map_blocks_iter_ctx' to clean up
z_erofs_map_blocks_iter and vle_get_logical_extent_head.

It changes the return value of `vle_get_logical_extent_head' to int
for the later error handing. In addition, it also renames `pcn' to
`pblk' since only `pblk' exists in erofs compression ondisk format.

Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
---
change log v3:
 - spilt into small patches at Chao's suggestion.

 drivers/staging/erofs/unzip_vle.c | 139 +++++++++++++++++++++-----------------
 1 file changed, 77 insertions(+), 62 deletions(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index f81b2a6..74d2530 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -1410,6 +1410,13 @@ static int z_erofs_vle_normalaccess_readpages(
 	.readpages = z_erofs_vle_normalaccess_readpages,
 };
 
+/*
+ * Variable-sized Logical Extent (Fixed Physical Cluster) Compression Mode
+ * ---
+ * VLE compression mode attempts to compress a number of logical data into
+ * a physical cluster with a fixed size.
+ * VLE compression mode uses "struct z_erofs_vle_decompressed_index".
+ */
 #define __vle_cluster_advise(x, bit, bits) \
 	((le16_to_cpu(x) >> (bit)) & ((1 << (bits)) - 1))
 
@@ -1465,90 +1472,95 @@ static int z_erofs_vle_normalaccess_readpages(
 	return erofs_blkoff(iloc(sbi, vi->nid) + ofs);
 }
 
-/*
- * Variable-sized Logical Extent (Fixed Physical Cluster) Compression Mode
- * ---
- * VLE compression mode attempts to compress a number of logical data into
- * a physical cluster with a fixed size.
- * VLE compression mode uses "struct z_erofs_vle_decompressed_index".
- */
-static erofs_off_t vle_get_logical_extent_head(
-	struct inode *inode,
-	struct page **page_iter,
-	void **kaddr_iter,
-	unsigned lcn,	/* logical cluster number */
-	erofs_blk_t *pcn,
-	unsigned *flags)
+struct vle_map_blocks_iter_ctx {
+	struct inode *inode;
+	struct super_block *sb;
+	unsigned int clusterbits;
+
+	struct page **mpage_ret;
+	void **kaddr_ret;
+};
+
+static int
+vle_get_logical_extent_head(const struct vle_map_blocks_iter_ctx *ctx,
+			    unsigned int lcn,	/* logical cluster number */
+			    unsigned long long *ofs,
+			    erofs_blk_t *pblk,
+			    unsigned int *flags)
 {
-	/* for extent meta */
-	struct page *page = *page_iter;
-	erofs_blk_t blkaddr = vle_extent_blkaddr(inode, lcn);
+	const unsigned int clustersize = 1 << ctx->clusterbits;
+	const erofs_blk_t mblk = vle_extent_blkaddr(ctx->inode, lcn);
+	struct page *mpage = *ctx->mpage_ret;	/* extent metapage */
+
 	struct z_erofs_vle_decompressed_index *di;
-	unsigned long long ofs;
-	struct super_block *const sb = inode->i_sb;
-	const unsigned int clusterbits = EROFS_SB(sb)->clusterbits;
-	const unsigned int clustersize = 1 << clusterbits;
-	unsigned delta0;
-
-	if (page->index != blkaddr) {
-		kunmap_atomic(*kaddr_iter);
-		unlock_page(page);
-		put_page(page);
+	unsigned int cluster_type, delta0;
+
+	if (mpage->index != mblk) {
+		kunmap_atomic(*ctx->kaddr_ret);
+		unlock_page(mpage);
+		put_page(mpage);
 
-		page = erofs_get_meta_page_nofail(sb, blkaddr, false);
-		*page_iter = page;
-		*kaddr_iter = kmap_atomic(page);
+		mpage = erofs_get_meta_page_nofail(ctx->sb, mblk, false);
+		*ctx->mpage_ret = mpage;
+		*ctx->kaddr_ret = kmap_atomic(mpage);
 	}
 
-	di = *kaddr_iter + vle_extent_blkoff(inode, lcn);
-	switch (vle_cluster_type(di)) {
+	di = *ctx->kaddr_ret + vle_extent_blkoff(ctx->inode, lcn);
+
+	cluster_type = vle_cluster_type(di);
+	switch (cluster_type) {
 	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
 		delta0 = le16_to_cpu(di->di_u.delta[0]);
 		DBG_BUGON(!delta0);
 		DBG_BUGON(lcn < delta0);
 
-		ofs = vle_get_logical_extent_head(inode,
-			page_iter, kaddr_iter,
-			lcn - delta0, pcn, flags);
-		break;
+		return vle_get_logical_extent_head(ctx,
+			lcn - delta0, ofs, pblk, flags);
 	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
 		*flags ^= EROFS_MAP_ZIPPED;
+		/* fallthrough */
 	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
 		/* clustersize should be a power of two */
-		ofs = ((u64)lcn << clusterbits) +
+		*ofs = ((u64)lcn << ctx->clusterbits) +
 			(le16_to_cpu(di->di_clusterofs) & (clustersize - 1));
-		*pcn = le32_to_cpu(di->di_u.blkaddr);
+		*pblk = le32_to_cpu(di->di_u.blkaddr);
 		break;
 	default:
 		BUG_ON(1);
 	}
-	return ofs;
+	return 0;
 }
 
 int z_erofs_map_blocks_iter(struct inode *inode,
 	struct erofs_map_blocks *map,
 	struct page **mpage_ret, int flags)
 {
+	void *kaddr;
+	const struct vle_map_blocks_iter_ctx ctx = {
+		.inode = inode,
+		.sb = inode->i_sb,
+		.clusterbits = EROFS_I_SB(inode)->clusterbits,
+		.mpage_ret = mpage_ret,
+		.kaddr_ret = &kaddr
+	};
+	const unsigned int clustersize = 1 << ctx.clusterbits;
+	/* if both m_(l,p)len are 0, regularize l_lblk, l_lofs, etc... */
+	const bool initial = !map->m_llen;
+
 	/* logicial extent (start, end) offset */
 	unsigned long long ofs, end;
-	struct z_erofs_vle_decompressed_index *di;
-	erofs_blk_t e_blkaddr, pcn;
-	unsigned lcn, logical_cluster_ofs, cluster_type;
+	unsigned int lcn;
 	u32 ofs_rem;
+
+	erofs_blk_t mblk, pblk;
 	struct page *mpage = *mpage_ret;
-	void *kaddr;
-	bool initial;
-	struct super_block *const sb = inode->i_sb;
-	const unsigned int clusterbits = EROFS_SB(sb)->clusterbits;
-	const unsigned int clustersize = 1 << clusterbits;
+	struct z_erofs_vle_decompressed_index *di;
+	unsigned int cluster_type, logical_cluster_ofs;
 	int err = 0;
 
-	/* if both m_(l,p)len are 0, regularize l_lblk, l_lofs, etc... */
-	initial = !map->m_llen;
-
 	/* when trying to read beyond EOF, leave it unmapped */
 	if (unlikely(map->m_la >= inode->i_size)) {
-		BUG_ON(!initial);
+		DBG_BUGON(!initial);
 		map->m_llen = map->m_la + 1 - inode->i_size;
 		map->m_la = inode->i_size;
 		map->m_flags = 0;
@@ -1561,16 +1573,16 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 	ofs = map->m_la + map->m_llen;
 
 	/* clustersize should be power of two */
-	lcn = ofs >> clusterbits;
+	lcn = ofs >> ctx.clusterbits;
 	ofs_rem = ofs & (clustersize - 1);
 
-	e_blkaddr = vle_extent_blkaddr(inode, lcn);
+	mblk = vle_extent_blkaddr(inode, lcn);
 
-	if (mpage == NULL || mpage->index != e_blkaddr) {
+	if (mpage == NULL || mpage->index != mblk) {
 		if (mpage != NULL)
 			put_page(mpage);
 
-		mpage = erofs_get_meta_page_nofail(sb, e_blkaddr, false);
+		mpage = erofs_get_meta_page_nofail(ctx.sb, mblk, false);
 		*mpage_ret = mpage;
 	} else {
 		lock_page(mpage);
@@ -1580,8 +1592,8 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 	kaddr = kmap_atomic(mpage);
 	di = kaddr + vle_extent_blkoff(inode, lcn);
 
-	debugln("%s, lcn %u e_blkaddr %u e_blkoff %u", __func__, lcn,
-		e_blkaddr, vle_extent_blkoff(inode, lcn));
+	debugln("%s, lcn %u mblk %u e_blkoff %u", __func__, lcn,
+		mblk, vle_extent_blkoff(inode, lcn));
 
 	err = vle_decompressed_index_clusterofs(&logical_cluster_ofs,
 						clustersize, di);
@@ -1608,13 +1620,13 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 		/* fallthrough */
 	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
 		if (ofs_rem == logical_cluster_ofs) {
-			pcn = le32_to_cpu(di->di_u.blkaddr);
+			pblk = le32_to_cpu(di->di_u.blkaddr);
 			goto exact_hitted;
 		}
 
 		if (ofs_rem > logical_cluster_ofs) {
 			ofs = (u64)lcn * clustersize | logical_cluster_ofs;
-			pcn = le32_to_cpu(di->di_u.blkaddr);
+			pblk = le32_to_cpu(di->di_u.blkaddr);
 			break;
 		}
 
@@ -1629,9 +1641,12 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 		/* fallthrough */
 	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
 		/* get the correspoinding first chunk */
-		ofs = vle_get_logical_extent_head(inode, mpage_ret,
-			&kaddr, lcn, &pcn, &map->m_flags);
+		err = vle_get_logical_extent_head(&ctx, lcn, &ofs,
+						  &pblk, &map->m_flags);
 		mpage = *mpage_ret;
+
+		if (unlikely(err))
+			goto unmap_out;
 		break;
 	default:
 		errln("unknown cluster type %u at offset %llu of nid %llu",
@@ -1644,7 +1659,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 exact_hitted:
 	map->m_llen = end - ofs;
 	map->m_plen = clustersize;
-	map->m_pa = blknr_to_addr(pcn);
+	map->m_pa = blknr_to_addr(pblk);
 	map->m_flags |= EROFS_MAP_MAPPED;
 unmap_out:
 	kunmap_atomic(kaddr);
-- 
1.9.1

[PREVIEW] [PATCH v3 08/10] staging: erofs: complete error handing of z_erofs_map_blocks_iter

[Gao Xiang]

This patch completes error handing of z_erofs_map_blocks_iter
and vle_get_logical_extent_head, including no memory and
io error cases.

Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
---
change log v3:
 - spilt into small patches at Chao's suggestion.

 drivers/staging/erofs/unzip_vle.c | 35 ++++++++++++++++++++++++++---------
 1 file changed, 26 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 74d2530..6c93877 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -1500,7 +1500,11 @@ struct vle_map_blocks_iter_ctx {
 		unlock_page(mpage);
 		put_page(mpage);
 
-		mpage = erofs_get_meta_page_nofail(ctx->sb, mblk, false);
+		mpage = erofs_get_meta_page(ctx->sb, mblk, false);
+		if (IS_ERR(mpage)) {
+			*ctx->mpage_ret = NULL;
+			return PTR_ERR(mpage);
+		}
 		*ctx->mpage_ret = mpage;
 		*ctx->kaddr_ret = kmap_atomic(mpage);
 	}
@@ -1511,9 +1515,12 @@ struct vle_map_blocks_iter_ctx {
 	switch (cluster_type) {
 	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
 		delta0 = le16_to_cpu(di->di_u.delta[0]);
-		DBG_BUGON(!delta0);
-		DBG_BUGON(lcn < delta0);
-
+		if (unlikely(!delta0 || delta0 > lcn)) {
+			errln("invalid NONHEAD dl0 %u at lcn %u of nid %llu",
+			      delta0, lcn, EROFS_V(ctx->inode)->nid);
+			DBG_BUGON(1);
+			return -EIO;
+		}
 		return vle_get_logical_extent_head(ctx,
 			lcn - delta0, ofs, pblk, flags);
 	case Z_EROFS_VLE_CLUSTER_TYPE_PLAIN:
@@ -1526,7 +1533,10 @@ struct vle_map_blocks_iter_ctx {
 		*pblk = le32_to_cpu(di->di_u.blkaddr);
 		break;
 	default:
-		BUG_ON(1);
+		errln("unknown cluster type %u at lcn %u of nid %llu",
+		      cluster_type, lcn, EROFS_V(ctx->inode)->nid);
+		DBG_BUGON(1);
+		return -EIO;
 	}
 	return 0;
 }
@@ -1582,7 +1592,11 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 		if (mpage != NULL)
 			put_page(mpage);
 
-		mpage = erofs_get_meta_page_nofail(ctx.sb, mblk, false);
+		mpage = erofs_get_meta_page(ctx.sb, mblk, false);
+		if (IS_ERR(mpage)) {
+			err = PTR_ERR(mpage);
+			goto out;
+		}
 		*mpage_ret = mpage;
 	} else {
 		lock_page(mpage);
@@ -1645,8 +1659,11 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 						  &pblk, &map->m_flags);
 		mpage = *mpage_ret;
 
-		if (unlikely(err))
-			goto unmap_out;
+		if (unlikely(err)) {
+			if (mpage != NULL)
+				goto unmap_out;
+			goto out;
+		}
 		break;
 	default:
 		errln("unknown cluster type %u at offset %llu of nid %llu",
@@ -1670,7 +1687,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 		map->m_llen, map->m_plen, map->m_flags);
 
 	/* aggressively BUG_ON iff CONFIG_EROFS_FS_DEBUG is on */
-	DBG_BUGON(err < 0);
+	DBG_BUGON(err < 0 && err != -ENOMEM);
 	return err;
 }
 
-- 
1.9.1

[PREVIEW] [PATCH v2 09/10] staging: erofs: fix a bug when appling cache strategy

[Gao Xiang]

As described in Kconfig, the last compressed pack should be cached
for further reading for either `EROFS_FS_ZIP_CACHE_UNIPOLAR' or
`EROFS_FS_ZIP_CACHE_BIPOLAR' by design.

However, there is a bug in z_erofs_do_read_page, it will
switch `initial' to `false' at the very beginning before it decides
to cache the last compressed pack.

caching strategy should work properly after appling this patch.

Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
---
change log v2:
 - spilt into small patches at Chao's suggestion.

 drivers/staging/erofs/unzip_vle.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 6c93877..1f64cb1 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -629,7 +629,7 @@ static int z_erofs_do_read_page(struct z_erofs_vle_frontend *fe,
 	/* go ahead the next map_blocks */
 	debugln("%s: [out-of-range] pos %llu", __func__, offset + cur);
 
-	if (!z_erofs_vle_work_iter_end(builder))
+	if (z_erofs_vle_work_iter_end(builder))
 		fe->initial = false;
 
 	map->m_la = offset + cur;
-- 
1.9.1

[PREVIEW] [PATCH v2 10/10] staging: erofs: complete error handing of z_erofs_do_read_page

[Gao Xiang]

This patch completes error handing code of z_erofs_do_read_page.
PG_error will be set when some read error happens, therefore
z_erofs_onlinepage_endio will unlock this page without setting
PG_uptodate.

Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
---
change log v2:
 - spilt into small patches at Chao's suggestion.

 drivers/staging/erofs/unzip_vle.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 1f64cb1..1d0ffa6 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -611,7 +611,7 @@ static int z_erofs_do_read_page(struct z_erofs_vle_frontend *fe,
 
 	enum z_erofs_page_type page_type;
 	unsigned cur, end, spiltted, index;
-	int err;
+	int err = 0;
 
 	/* register locked file pages as online pages in pack */
 	z_erofs_onlinepage_init(page);
@@ -638,12 +638,11 @@ static int z_erofs_do_read_page(struct z_erofs_vle_frontend *fe,
 	if (unlikely(err))
 		goto err_out;
 
-	/* deal with hole (FIXME! broken now) */
 	if (unlikely(!(map->m_flags & EROFS_MAP_MAPPED)))
 		goto hitted;
 
 	DBG_BUGON(map->m_plen != 1 << sbi->clusterbits);
-	BUG_ON(erofs_blkoff(map->m_pa));
+	DBG_BUGON(erofs_blkoff(map->m_pa));
 
 	err = z_erofs_vle_work_iter_begin(builder, sb, map, &fe->owned_head);
 	if (unlikely(err))
@@ -688,7 +687,7 @@ static int z_erofs_do_read_page(struct z_erofs_vle_frontend *fe,
 
 		err = z_erofs_vle_work_add_page(builder,
 			newpage, Z_EROFS_PAGE_TYPE_EXCLUSIVE);
-		if (!err)
+		if (likely(!err))
 			goto retry;
 	}
 
@@ -699,9 +698,10 @@ static int z_erofs_do_read_page(struct z_erofs_vle_frontend *fe,
 
 	/* FIXME! avoid the last relundant fixup & endio */
 	z_erofs_onlinepage_fixup(page, index, true);
-	++spiltted;
 
-	/* also update nr_pages and increase queued_pages */
+	/* bump up the number of spiltted parts of a page */
+	++spiltted;
+	/* also update nr_pages */
 	work->nr_pages = max_t(pgoff_t, work->nr_pages, index + 1);
 next_part:
 	/* can be used for verification */
@@ -711,16 +711,18 @@ static int z_erofs_do_read_page(struct z_erofs_vle_frontend *fe,
 	if (end > 0)
 		goto repeat;
 
+out:
 	/* FIXME! avoid the last relundant fixup & endio */
 	z_erofs_onlinepage_endio(page);
 
 	debugln("%s, finish page: %pK spiltted: %u map->m_llen %llu",
 		__func__, page, spiltted, map->m_llen);
-	return 0;
+	return err;
 
+	/* if some error occurred while processing this page */
 err_out:
-	/* TODO: the missing error handing cases */
-	return err;
+	SetPageError(page);
+	goto out;
 }
 
 static void z_erofs_vle_unzip_kickoff(void *ptr, int bios)
-- 
1.9.1

[PATCH v2 03/10] staging: erofs: fix vle_decompressed_index_clusterofs

[Chao Yu]

On 2018/8/11 4:10, Gao Xiang wrote:
> This patch adds error handing code, and fixes a missing
> endian conversion in vle_decompressed_index_clusterofs.
> 
> Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>

Reviewed-by: Chao Yu <yuchao0 at huawei.com>

Thanks,

[PATCH v3 04/10] staging: erofs: fix a missing endian conversion

[Chao Yu]

On 2018/8/11 4:10, Gao Xiang wrote:
> This patch fixes a missing endian conversion in
> vle_get_logical_extent_head.
> 
> Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>

Reviewed-by: Chao Yu <yuchao0 at huawei.com>

Thanks,

[PREVIEW] [PATCH v3 05/10] staging: erofs: fix integer overflow on 32-bit platform

[Chao Yu]

On 2018/8/11 4:10, Gao Xiang wrote:
> This patch fixes integer overflow on multiplication
> of 32-bit lcn in z_erofs_map_blocks_iter.
> 
> Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>

Reviewed-by: Chao Yu <yuchao0 at huawei.com>

Thanks,

[PREVIEW] [PATCH v3 06/10] staging: erofs: fix compression mapping beyond EOF

[Chao Yu]

On 2018/8/11 4:10, Gao Xiang wrote:
> Logical address of EOF LTP mapping should start at
> `inode->i_size' rather than `inode->i_size - 1' to
> `m_la(in) + 1 - inode->i_size', fix it.
> 
> Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>

Reviewed-by: Chao Yu <yuchao0 at huawei.com>

Thanks,

[PREVIEW] [PATCH v4 06/10] staging: erofs: fix compression mapping beyond EOF

[Gao Xiang]

From: Gao Xiang <gaoxiang25@huawei.com>

Logical address of EOF LTP mapping should start at
`inode->i_size' rather than `inode->i_size - 1' to
`m_la(in)', fix it.

Reviewed-by: Chao Yu <yuchao0 at huawei.com>
Signed-off-by: Chao Yu <yuchao0 at huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
---
change log v4:
 - fix the description `m_la(in) + 1 - inode->i_size' to
   `m_la(in)' in the commit message.

change log v3:
 - spilt into small patches at Chao's suggestion.

Hi Chao,
Please help use this commit message. Thanks.

Thanks,
Gao Xiang
 
 drivers/staging/erofs/unzip_vle.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 79d4ca0..aecf650 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -1548,7 +1548,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 	if (unlikely(map->m_la >= inode->i_size)) {
 		BUG_ON(!initial);
 		map->m_llen = map->m_la + 1 - inode->i_size;
-		map->m_la = inode->i_size - 1;
+		map->m_la = inode->i_size;
 		map->m_flags = 0;
 		goto out;
 	}
-- 
2.7.4

[PREVIEW] [PATCH v4 05/10] staging: erofs: fix integer overflow on 32-bit platform

[Gao Xiang]

From: Gao Xiang <gaoxiang25@huawei.com>

This patch fixes integer overflow on multiplication
of 32-bit `lcn' in z_erofs_map_blocks_iter.

Reviewed-by: Chao Yu <yuchao0 at huawei.com>
Signed-off-by: Chao Yu <yuchao0 at huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>
---
change log v4:
 - fix commit message a bit.
change log v3:
 - spilt into small patches at Chao's suggestion.

 drivers/staging/erofs/unzip_vle.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c
index 0accf1b..79d4ca0 100644
--- a/drivers/staging/erofs/unzip_vle.c
+++ b/drivers/staging/erofs/unzip_vle.c
@@ -1513,7 +1513,7 @@ static erofs_off_t vle_get_logical_extent_head(
 		*flags ^= EROFS_MAP_ZIPPED;
 	case Z_EROFS_VLE_CLUSTER_TYPE_HEAD:
 		/* clustersize should be a power of two */
-		ofs = ((unsigned long long)lcn << clusterbits) +
+		ofs = ((u64)lcn << clusterbits) +
 			(le16_to_cpu(di->di_clusterofs) & (clustersize - 1));
 		*pcn = le32_to_cpu(di->di_u.blkaddr);
 		break;
@@ -1595,7 +1595,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 	/* by default, compressed */
 	map->m_flags |= EROFS_MAP_ZIPPED;
 
-	end = (u64)(lcn + 1) * clustersize;
+	end = ((u64)lcn + 1) * clustersize;
 
 	cluster_type = vle_cluster_type(di);
 
@@ -1611,7 +1611,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 		}
 
 		if (ofs_rem > logical_cluster_ofs) {
-			ofs = lcn * clustersize | logical_cluster_ofs;
+			ofs = (u64)lcn * clustersize | logical_cluster_ofs;
 			pcn = le32_to_cpu(di->di_u.blkaddr);
 			break;
 		}
@@ -1623,7 +1623,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 			err = -EIO;
 			goto unmap_out;
 		}
-		end = (lcn-- * clustersize) | logical_cluster_ofs;
+		end = ((u64)lcn-- * clustersize) | logical_cluster_ofs;
 		/* fallthrough */
 	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
 		/* get the correspoinding first chunk */
-- 
2.7.4

[PREVIEW] [PATCH v3 07/10] staging: erofs: clean up z_erofs_map_blocks_iter

[Chao Yu]

On 2018/8/11 4:10, Gao Xiang wrote:
> This patch mainly introduces `vle_map_blocks_iter_ctx' to clean up
> z_erofs_map_blocks_iter and vle_get_logical_extent_head.
> 
> It changes the return value of `vle_get_logical_extent_head' to int
> for the later error handing. In addition, it also renames `pcn' to
> `pblk' since only `pblk' exists in erofs compression ondisk format.
> 
> Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>

Reviewed-by: Chao Yu <yuchao0 at huawei.com>

Thanks,

[PREVIEW] [PATCH v3 08/10] staging: erofs: complete error handing of z_erofs_map_blocks_iter

[Chao Yu]

On 2018/8/11 4:10, Gao Xiang wrote:
> This patch completes error handing of z_erofs_map_blocks_iter
> and vle_get_logical_extent_head, including no memory and
> io error cases.
> 
> Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>

Reviewed-by: Chao Yu <yuchao0 at huawei.com>

Thanks,

[PREVIEW] [PATCH v2 09/10] staging: erofs: fix a bug when appling cache strategy

[Chao Yu]

On 2018/8/11 4:10, Gao Xiang wrote:
> As described in Kconfig, the last compressed pack should be cached
> for further reading for either `EROFS_FS_ZIP_CACHE_UNIPOLAR' or
> `EROFS_FS_ZIP_CACHE_BIPOLAR' by design.
> 
> However, there is a bug in z_erofs_do_read_page, it will
> switch `initial' to `false' at the very beginning before it decides
> to cache the last compressed pack.
> 
> caching strategy should work properly after appling this patch.
> 
> Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>

Reviewed-by: Chao Yu <yuchao0 at huawei.com>

Thanks,

[PREVIEW] [PATCH v2 10/10] staging: erofs: complete error handing of z_erofs_do_read_page

[Chao Yu]

On 2018/8/11 4:10, Gao Xiang wrote:
> This patch completes error handing code of z_erofs_do_read_page.
> PG_error will be set when some read error happens, therefore
> z_erofs_onlinepage_endio will unlock this page without setting
> PG_uptodate.
> 
> Signed-off-by: Gao Xiang <gaoxiang25 at huawei.com>

Reviewed-by: Chao Yu <yuchao0 at huawei.com>

Thanks,