Re: [PATCH] AOSP: erofs-utils: fix sub directory prefix path in canned fs_config

[Gao Xiang <hsiangkao@redhat.com>]

Hi Yue,

On Tue, Dec 22, 2020 at 02:31:12PM +0800, Gao Xiang wrote:

...

> 
> Ok, I will try to find some clue to verify later.
> 
> > 
> > > 
> > > > Moreover, we should not add the mount point to fspath on root inode for
> > > > fs_config() branch.  
> > > 
> > > Is there some descriptive words or reference for this? To be honest,
> > > I'm quite unsure about this kind of Android-specific things... :(
> > 
> > Refer to change: mksquashfs: Run android_fs_config() on the root inode
> > 
> > I think erofs of AOSP has this issue also. Am i right?
> 
> Not quite sure if it effects non-canned fs_config after
> reading the commit message...
> https://android.googlesource.com/platform/external/squashfs-tools/+/85a6bc1e52bb911f195c5dc0890717913938c2d1%5E%21/#F0
> 
> And no permission to access Bug 72745016, so...
> maybe we need to limit this to non-canned fs_config only?
> (at least confirming the original case would be better)
> 
> BTW, Also, from its testcase command line in the commit message:
> "mksquashfs path system.raw.img -fs-config-file fs_config -android-fs-config"
> 
> I'm not sure if "--mount-point" is passed in so I think for
> such case no need to use such "goto" as well? 
> 
> Thanks,
> Gao Xiang

Could you verify the following patch if possible? (without compilation,
I don't have test environment now since AOSP code is on my PC)

From: Yue Hu <huyue2@yulong.com>
Date: Tue, 22 Dec 2020 14:52:22 +0800
Subject: [PATCH] AOSP: erofs-utils: fix sub-directory prefix for canned
 fs_config

"failed to find [%s] in canned fs_config" is observed by using
"--fs-config-file" option under Android 10.

Notice that canned fs_config has a prefix to sub-directory if
"--mount-point" presents. However, such prefix cannot be added by
just using erofs_fspath().

Fixes: 8a9e8046f170 ("AOSP: erofs-utils: add fs_config support")
Signed-off-by: Yue Hu <huyue2@yulong.com>
Signed-off-by: Gao Xiang <hsiangkao@aol.com>
---
 lib/inode.c | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/lib/inode.c b/lib/inode.c
index 3d634fc..9469074 100644
--- a/lib/inode.c
+++ b/lib/inode.c
@@ -701,21 +701,25 @@ int erofs_droid_inode_fsconfig(struct erofs_inode *inode,
 	char *fspath;
 
 	inode->capabilities = 0;
+	if (!cfg.mount_point)
+		fspath = erofs_fspath(path);
+	else if (asprintf(&fspath, "%s/%s", cfg.mount_point,
+			  erofs_fspath(path)) <= 0)
+		return -ENOMEM;
+
+
 	if (cfg.fs_config_file)
-		canned_fs_config(erofs_fspath(path),
+		canned_fs_config(fspath,
 				 S_ISDIR(st->st_mode),
 				 cfg.target_out_path,
 				 &uid, &gid, &mode, &inode->capabilities);
-	else if (cfg.mount_point) {
-		if (asprintf(&fspath, "%s/%s", cfg.mount_point,
-			     erofs_fspath(path)) <= 0)
-			return -ENOMEM;
-
+	else
 		fs_config(fspath, S_ISDIR(st->st_mode),
 			  cfg.target_out_path,
 			  &uid, &gid, &mode, &inode->capabilities);
+
+	if (cfg.mount_point)
 		free(fspath);
-	}
 	st->st_uid = uid;
 	st->st_gid = gid;
 	st->st_mode = mode | stat_file_type_mask;
-- 
2.27.0