[PATCH 6.1.y] erofs: get rid of z_erofs_fill_inode()

[PATCH 6.1.y] erofs: get rid of z_erofs_fill_inode()

[driz2t]

[-- Attachment #1: Type: text/plain, Size: 194 bytes --]

Hi,

Please test this patch on stable 6.1.y.

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git f2ddafa93a259310ca47507153b7811ec54ab7fd


Thanks,
Changjian Liu

[-- Attachment #2: 016d861797fd718491a8.patch --]
[-- Type: application/octet-stream, Size: 3163 bytes --]

From e27e3ce3ce3426ad02052bd297b7eb5cbf328e88 Mon Sep 17 00:00:00 2001
From: Changjian Liu <driz2t@qq.com>
Date: Tue, 24 Mar 2026 19:52:36 +0800
Subject: [PATCH] erofs: get rid of z_erofs_fill_inode()

This is a backport of upstream commit 4fdadd5b0f0c723c812842454f8cca1619f2e731.

Prior to big pclusters, non-compact compression indexes could have
empty headers.

Let's just avoid the legacy path since it can be handled properly
as a specific compression header with z_erofs_fill_inode_lazy() too.

Tested with erofs-utils exist versions.

Cc: stable@vger.kernel.org
(cherry picked from commit 4fdadd5b0f0c723c812842454f8cca1619f2e731)
Signed-off-by: Changjian Liu <driz2t@qq.com>
---
 fs/erofs/inode.c     |  12 ++++++++----
 fs/erofs/internal.h  |   2 --
 fs/erofs/zmap.c      |  18 ------------------
 scripts/extract-cert | Bin 0 -> 14608 bytes
 4 files changed, 8 insertions(+), 24 deletions(-)
 create mode 100755 scripts/extract-cert

diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index 3cbef6318b7b..484572504b4d 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -280,11 +280,15 @@ static int erofs_fill_inode(struct inode *inode)
 	}
 
 	if (erofs_inode_is_data_compressed(vi->datalayout)) {
+#ifdef CONFIG_EROFS_FS_ZIP
 		if (!erofs_is_fscache_mode(inode->i_sb) &&
-		    inode->i_sb->s_blocksize_bits == PAGE_SHIFT)
-			err = z_erofs_fill_inode(inode);
-		else
-			err = -EOPNOTSUPP;
+		    inode->i_sb->s_blocksize_bits == PAGE_SHIFT) {
+			inode->i_mapping->a_ops = &z_erofs_aops;
+			err = 0;
+			goto out_unlock;
+		}
+#endif
+		err = -EOPNOTSUPP;
 		goto out_unlock;
 	}
 	inode->i_mapping->a_ops = &erofs_raw_access_aops;
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 126970932805..1a4d08a93339 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -423,12 +423,10 @@ enum {
 extern const struct iomap_ops z_erofs_iomap_report_ops;
 
 #ifdef CONFIG_EROFS_FS_ZIP
-int z_erofs_fill_inode(struct inode *inode);
 int z_erofs_map_blocks_iter(struct inode *inode,
 			    struct erofs_map_blocks *map,
 			    int flags);
 #else
-static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP; }
 static inline int z_erofs_map_blocks_iter(struct inode *inode,
 					  struct erofs_map_blocks *map,
 					  int flags)
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index d2d7fe826091..ff84533da0c4 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -7,24 +7,6 @@
 #include <asm/unaligned.h>
 #include <trace/events/erofs.h>
 
-int z_erofs_fill_inode(struct inode *inode)
-{
-	struct erofs_inode *const vi = EROFS_I(inode);
-	struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
-
-	if (!erofs_sb_has_big_pcluster(sbi) &&
-	    !erofs_sb_has_ztailpacking(sbi) && !erofs_sb_has_fragments(sbi) &&
-	    vi->datalayout == EROFS_INODE_COMPRESSED_FULL) {
-		vi->z_advise = 0;
-		vi->z_algorithmtype[0] = 0;
-		vi->z_algorithmtype[1] = 0;
-		vi->z_logical_clusterbits = inode->i_sb->s_blocksize_bits;
-		set_bit(EROFS_I_Z_INITED_BIT, &vi->flags);
-	}
-	inode->i_mapping->a_ops = &z_erofs_aops;
-	return 0;
-}
-
 struct z_erofs_maprecorder {
 	struct inode *inode;
 	struct erofs_map_blocks *map;
-- 
2.43.0

Re: [v6.1] WARNING in iomap_iter

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+016d861797fd718491a8@syzkaller.appspotmail.com
Tested-by: syzbot+016d861797fd718491a8@syzkaller.appspotmail.com

Tested on:

commit:         f2ddafa9 Linux 6.1.166
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=16c916da580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2b89c38cfc7d08c1
dashboard link: https://syzkaller.appspot.com/bug?extid=016d861797fd718491a8
compiler:       Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=168c506a580000

Note: testing is done by a robot and is best-effort only.