[PATCH v2 1/2] erofs: simplify tail inline pcluster handling

[PATCH v2 1/2] erofs: simplify tail inline pcluster handling

[Gao Xiang]

Commit ab92184ff8f1 ("erofs: add on-disk compressed tail-packing inline
support") introduced the flag `Z_EROFS_ADVISE_INLINE_PCLUSTER`, which is
redundant because `h_idata_size != 0` serves the same purpose.

Additionally, merge `z_idataoff` and `z_fragmentoff` since these two
features are mutually exclusive for a given inode.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
---
new patch.

 fs/erofs/internal.h |  9 ++-------
 fs/erofs/zmap.c     | 19 ++++++++++---------
 2 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index f955793146f4..afce4b03f586 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -265,13 +265,8 @@ struct erofs_inode {
 			unsigned char  z_algorithmtype[2];
 			unsigned char  z_logical_clusterbits;
 			unsigned long  z_tailextent_headlcn;
-			union {
-				struct {
-					erofs_off_t    z_idataoff;
-					unsigned short z_idata_size;
-				};
-				erofs_off_t z_fragmentoff;
-			};
+			erofs_off_t    z_fragmentoff;
+			unsigned short z_idata_size;
 		};
 #endif	/* CONFIG_EROFS_FS_ZIP */
 	};
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index a0c1c6450a55..9518d341cd82 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -395,8 +395,8 @@ static int z_erofs_do_map_blocks(struct inode *inode,
 				 struct erofs_map_blocks *map, int flags)
 {
 	struct erofs_inode *const vi = EROFS_I(inode);
-	bool ztailpacking = vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER;
 	bool fragment = vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
+	bool ztailpacking = vi->z_idata_size;
 	struct z_erofs_maprecorder m = {
 		.inode = inode,
 		.map = map,
@@ -415,9 +415,8 @@ static int z_erofs_do_map_blocks(struct inode *inode,
 	if (err)
 		goto unmap_out;
 
-	if (ztailpacking && (flags & EROFS_GET_BLOCKS_FINDTAIL))
-		vi->z_idataoff = m.nextpackoff;
-
+	if ((flags & EROFS_GET_BLOCKS_FINDTAIL) && ztailpacking)
+		vi->z_fragmentoff = m.nextpackoff;
 	map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_ENCODED;
 	end = (m.lcn + 1ULL) << lclusterbits;
 
@@ -472,7 +471,7 @@ static int z_erofs_do_map_blocks(struct inode *inode,
 	}
 	if (ztailpacking && m.lcn == vi->z_tailextent_headlcn) {
 		map->m_flags |= EROFS_MAP_META;
-		map->m_pa = vi->z_idataoff;
+		map->m_pa = vi->z_fragmentoff;
 		map->m_plen = vi->z_idata_size;
 	} else if (fragment && m.lcn == vi->z_tailextent_headlcn) {
 		map->m_flags |= EROFS_MAP_FRAGMENT;
@@ -565,6 +564,10 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
 	vi->z_advise = le16_to_cpu(h->h_advise);
 	vi->z_algorithmtype[0] = h->h_algorithmtype & 15;
 	vi->z_algorithmtype[1] = h->h_algorithmtype >> 4;
+	if (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER)
+		vi->z_fragmentoff = le32_to_cpu(h->h_fragmentoff);
+	else
+		vi->z_idata_size = le16_to_cpu(h->h_idata_size);
 
 	headnr = 0;
 	if (vi->z_algorithmtype[0] >= Z_EROFS_COMPRESSION_MAX ||
@@ -593,18 +596,16 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
 		goto out_put_metabuf;
 	}
 
-	if (vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER) {
+	if (vi->z_idata_size) {
 		struct erofs_map_blocks map = {
 			.buf = __EROFS_BUF_INITIALIZER
 		};
 
-		vi->z_idata_size = le16_to_cpu(h->h_idata_size);
 		err = z_erofs_do_map_blocks(inode, &map,
 					    EROFS_GET_BLOCKS_FINDTAIL);
 		erofs_put_metabuf(&map.buf);
 
-		if (!map.m_plen ||
-		    erofs_blkoff(sb, map.m_pa) + map.m_plen > sb->s_blocksize) {
+		if (erofs_blkoff(sb, map.m_pa) + map.m_plen > sb->s_blocksize) {
 			erofs_err(sb, "invalid tail-packing pclustersize %llu",
 				  map.m_plen);
 			err = -EFSCORRUPTED;
-- 
2.43.5

[PATCH v2 2/2] erofs: clean up header parsing for ztailpacking and fragments

[Gao Xiang]

Simplify the logic in z_erofs_fill_inode_lazy() by combining the
handling of ztailpacking and fragments, as they are mutually exclusive.

Note that `h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT` is handled
above, so no need to duplicate the check.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
---
v2:
 - rebase on the previous one;

 fs/erofs/zmap.c | 40 ++++++++++++++--------------------------
 1 file changed, 14 insertions(+), 26 deletions(-)

diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 9518d341cd82..dd120306a272 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -394,7 +394,8 @@ static int z_erofs_get_extent_decompressedlen(struct z_erofs_maprecorder *m)
 static int z_erofs_do_map_blocks(struct inode *inode,
 				 struct erofs_map_blocks *map, int flags)
 {
-	struct erofs_inode *const vi = EROFS_I(inode);
+	struct erofs_inode *vi = EROFS_I(inode);
+	struct super_block *sb = inode->i_sb;
 	bool fragment = vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
 	bool ztailpacking = vi->z_idata_size;
 	struct z_erofs_maprecorder m = {
@@ -438,7 +439,7 @@ static int z_erofs_do_map_blocks(struct inode *inode,
 		}
 		/* m.lcn should be >= 1 if endoff < m.clusterofs */
 		if (!m.lcn) {
-			erofs_err(inode->i_sb, "invalid logical cluster 0 at nid %llu",
+			erofs_err(sb, "invalid logical cluster 0 at nid %llu",
 				  vi->nid);
 			err = -EFSCORRUPTED;
 			goto unmap_out;
@@ -454,7 +455,7 @@ static int z_erofs_do_map_blocks(struct inode *inode,
 			goto unmap_out;
 		break;
 	default:
-		erofs_err(inode->i_sb, "unknown type %u @ offset %llu of nid %llu",
+		erofs_err(sb, "unknown type %u @ offset %llu of nid %llu",
 			  m.type, ofs, vi->nid);
 		err = -EOPNOTSUPP;
 		goto unmap_out;
@@ -473,10 +474,16 @@ static int z_erofs_do_map_blocks(struct inode *inode,
 		map->m_flags |= EROFS_MAP_META;
 		map->m_pa = vi->z_fragmentoff;
 		map->m_plen = vi->z_idata_size;
+		if (erofs_blkoff(sb, map->m_pa) + map->m_plen > sb->s_blocksize) {
+			erofs_err(sb, "invalid tail-packing pclustersize %llu",
+				  map->m_plen);
+			err = -EFSCORRUPTED;
+			goto unmap_out;
+		}
 	} else if (fragment && m.lcn == vi->z_tailextent_headlcn) {
 		map->m_flags |= EROFS_MAP_FRAGMENT;
 	} else {
-		map->m_pa = erofs_pos(inode->i_sb, m.pblk);
+		map->m_pa = erofs_pos(sb, m.pblk);
 		err = z_erofs_get_extent_compressedlen(&m, initial_lcn);
 		if (err)
 			goto unmap_out;
@@ -495,7 +502,7 @@ static int z_erofs_do_map_blocks(struct inode *inode,
 		afmt = m.headtype == Z_EROFS_LCLUSTER_TYPE_HEAD2 ?
 			vi->z_algorithmtype[1] : vi->z_algorithmtype[0];
 		if (!(EROFS_I_SB(inode)->available_compr_algs & (1 << afmt))) {
-			erofs_err(inode->i_sb, "inconsistent algorithmtype %u for nid %llu",
+			erofs_err(sb, "inconsistent algorithmtype %u for nid %llu",
 				  afmt, vi->nid);
 			err = -EFSCORRUPTED;
 			goto unmap_out;
@@ -596,31 +603,12 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
 		goto out_put_metabuf;
 	}
 
-	if (vi->z_idata_size) {
+	if (vi->z_idata_size ||
+	    (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER)) {
 		struct erofs_map_blocks map = {
 			.buf = __EROFS_BUF_INITIALIZER
 		};
 
-		err = z_erofs_do_map_blocks(inode, &map,
-					    EROFS_GET_BLOCKS_FINDTAIL);
-		erofs_put_metabuf(&map.buf);
-
-		if (erofs_blkoff(sb, map.m_pa) + map.m_plen > sb->s_blocksize) {
-			erofs_err(sb, "invalid tail-packing pclustersize %llu",
-				  map.m_plen);
-			err = -EFSCORRUPTED;
-		}
-		if (err < 0)
-			goto out_put_metabuf;
-	}
-
-	if (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER &&
-	    !(h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT)) {
-		struct erofs_map_blocks map = {
-			.buf = __EROFS_BUF_INITIALIZER
-		};
-
-		vi->z_fragmentoff = le32_to_cpu(h->h_fragmentoff);
 		err = z_erofs_do_map_blocks(inode, &map,
 					    EROFS_GET_BLOCKS_FINDTAIL);
 		erofs_put_metabuf(&map.buf);
-- 
2.43.5

Re: [PATCH v2 2/2] erofs: clean up header parsing for ztailpacking and fragments

[Chao Yu]

On 2025/2/24 20:37, Gao Xiang wrote:
> Simplify the logic in z_erofs_fill_inode_lazy() by combining the
> handling of ztailpacking and fragments, as they are mutually exclusive.
> 
> Note that `h->h_clusterbits >> Z_EROFS_FRAGMENT_INODE_BIT` is handled
> above, so no need to duplicate the check.
> 
> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,

Re: [PATCH v2 1/2] erofs: simplify tail inline pcluster handling

[Gao Xiang]

On 2025/2/24 20:37, Gao Xiang wrote:
> Commit ab92184ff8f1 ("erofs: add on-disk compressed tail-packing inline
> support") introduced the flag `Z_EROFS_ADVISE_INLINE_PCLUSTER`, which is
> redundant because `h_idata_size != 0` serves the same purpose.
> 
> Additionally, merge `z_idataoff` and `z_fragmentoff` since these two
> features are mutually exclusive for a given inode.
> 
> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
> ---
> new patch.

Note that `Z_EROFS_ADVISE_INLINE_PCLUSTER` now is left for
the compatibility purposes, only `mkfs.erofs` uses it in
the future.

Thanks,
Gao Xiang

[PATCH v3 1/2] erofs: simplify tail inline pcluster handling

[Gao Xiang]

Use `z_idata_size != 0` to indicate that ztailpacking is enabled.
`Z_EROFS_ADVISE_INLINE_PCLUSTER` cannot be ignored, as `h_idata_size`
could be non-zero prior to erofs-utils 1.6 [1].

Additionally, merge `z_idataoff` and `z_fragmentoff` since these two
features are mutually exclusive for a given inode.

[1] https://git.kernel.org/xiang/erofs-utils/c/547bea3cb71a
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
---
change since v2:
 - should not ignore `Z_EROFS_ADVISE_INLINE_PCLUSTER` as mentioned in
   the new commit message.

 fs/erofs/internal.h |  9 ++-------
 fs/erofs/zmap.c     | 20 ++++++++++----------
 2 files changed, 12 insertions(+), 17 deletions(-)

diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index b452b6557aa5..b357cbbce764 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -263,13 +263,8 @@ struct erofs_inode {
 			unsigned char  z_algorithmtype[2];
 			unsigned char  z_logical_clusterbits;
 			unsigned long  z_tailextent_headlcn;
-			union {
-				struct {
-					erofs_off_t    z_idataoff;
-					unsigned short z_idata_size;
-				};
-				erofs_off_t z_fragmentoff;
-			};
+			erofs_off_t    z_fragmentoff;
+			unsigned short z_idata_size;
 		};
 #endif	/* CONFIG_EROFS_FS_ZIP */
 	};
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index a0c1c6450a55..ba4533eabc6a 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -395,8 +395,8 @@ static int z_erofs_do_map_blocks(struct inode *inode,
 				 struct erofs_map_blocks *map, int flags)
 {
 	struct erofs_inode *const vi = EROFS_I(inode);
-	bool ztailpacking = vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER;
 	bool fragment = vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER;
+	bool ztailpacking = vi->z_idata_size;
 	struct z_erofs_maprecorder m = {
 		.inode = inode,
 		.map = map,
@@ -415,9 +415,8 @@ static int z_erofs_do_map_blocks(struct inode *inode,
 	if (err)
 		goto unmap_out;
 
-	if (ztailpacking && (flags & EROFS_GET_BLOCKS_FINDTAIL))
-		vi->z_idataoff = m.nextpackoff;
-
+	if ((flags & EROFS_GET_BLOCKS_FINDTAIL) && ztailpacking)
+		vi->z_fragmentoff = m.nextpackoff;
 	map->m_flags = EROFS_MAP_MAPPED | EROFS_MAP_ENCODED;
 	end = (m.lcn + 1ULL) << lclusterbits;
 
@@ -472,7 +471,7 @@ static int z_erofs_do_map_blocks(struct inode *inode,
 	}
 	if (ztailpacking && m.lcn == vi->z_tailextent_headlcn) {
 		map->m_flags |= EROFS_MAP_META;
-		map->m_pa = vi->z_idataoff;
+		map->m_pa = vi->z_fragmentoff;
 		map->m_plen = vi->z_idata_size;
 	} else if (fragment && m.lcn == vi->z_tailextent_headlcn) {
 		map->m_flags |= EROFS_MAP_FRAGMENT;
@@ -565,6 +564,10 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
 	vi->z_advise = le16_to_cpu(h->h_advise);
 	vi->z_algorithmtype[0] = h->h_algorithmtype & 15;
 	vi->z_algorithmtype[1] = h->h_algorithmtype >> 4;
+	if (vi->z_advise & Z_EROFS_ADVISE_FRAGMENT_PCLUSTER)
+		vi->z_fragmentoff = le32_to_cpu(h->h_fragmentoff);
+	else if (vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER)
+		vi->z_idata_size = le16_to_cpu(h->h_idata_size);
 
 	headnr = 0;
 	if (vi->z_algorithmtype[0] >= Z_EROFS_COMPRESSION_MAX ||
@@ -593,18 +596,16 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
 		goto out_put_metabuf;
 	}
 
-	if (vi->z_advise & Z_EROFS_ADVISE_INLINE_PCLUSTER) {
+	if (vi->z_idata_size) {
 		struct erofs_map_blocks map = {
 			.buf = __EROFS_BUF_INITIALIZER
 		};
 
-		vi->z_idata_size = le16_to_cpu(h->h_idata_size);
 		err = z_erofs_do_map_blocks(inode, &map,
 					    EROFS_GET_BLOCKS_FINDTAIL);
 		erofs_put_metabuf(&map.buf);
 
-		if (!map.m_plen ||
-		    erofs_blkoff(sb, map.m_pa) + map.m_plen > sb->s_blocksize) {
+		if (erofs_blkoff(sb, map.m_pa) + map.m_plen > sb->s_blocksize) {
 			erofs_err(sb, "invalid tail-packing pclustersize %llu",
 				  map.m_plen);
 			err = -EFSCORRUPTED;
@@ -619,7 +620,6 @@ static int z_erofs_fill_inode_lazy(struct inode *inode)
 			.buf = __EROFS_BUF_INITIALIZER
 		};
 
-		vi->z_fragmentoff = le32_to_cpu(h->h_fragmentoff);
 		err = z_erofs_do_map_blocks(inode, &map,
 					    EROFS_GET_BLOCKS_FINDTAIL);
 		erofs_put_metabuf(&map.buf);
-- 
2.43.5

Re: [PATCH v3 1/2] erofs: simplify tail inline pcluster handling

[Chao Yu]

On 2025/2/25 19:40, Gao Xiang wrote:
> Use `z_idata_size != 0` to indicate that ztailpacking is enabled.
> `Z_EROFS_ADVISE_INLINE_PCLUSTER` cannot be ignored, as `h_idata_size`
> could be non-zero prior to erofs-utils 1.6 [1].
> 
> Additionally, merge `z_idataoff` and `z_fragmentoff` since these two
> features are mutually exclusive for a given inode.
> 
> [1] https://git.kernel.org/xiang/erofs-utils/c/547bea3cb71a
> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,