When mounting different mount points with casefold support, they should
use the same encoding version and have the same flags to avoid any kind
of incompatibility issues.
Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>
---
fs/overlayfs/super.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index df85a76597e910d00323018f1d2cd720c5db921d..bcb7f5dbf9a32e4aa09bc41596be443851e21200 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -998,6 +998,7 @@ static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs,
int err;
unsigned int i;
size_t nr_merged_lower;
+ struct super_block *sb1 = NULL;
ofs->fs = kcalloc(ctx->nr + 2, sizeof(struct ovl_sb), GFP_KERNEL);
if (ofs->fs == NULL)
@@ -1024,6 +1025,8 @@ static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs,
if (ovl_upper_mnt(ofs)) {
ofs->fs[0].sb = ovl_upper_mnt(ofs)->mnt_sb;
ofs->fs[0].is_lower = false;
+
+ sb1 = ofs->fs[0].sb;
}
nr_merged_lower = ctx->nr - ctx->nr_data;
@@ -1067,6 +1070,9 @@ static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs,
return err;
}
+ if (!sb1)
+ sb1 = mnt->mnt_sb;
+
/*
* Make lower layers R/O. That way fchmod/fchown on lower file
* will fail instead of modifying lower fs.
@@ -1083,6 +1089,11 @@ static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs,
l->name = NULL;
ofs->numlayer++;
ofs->fs[fsid].is_lower = true;
+
+ if (!sb_same_encoding(sb1, mnt->mnt_sb)) {
+ pr_err("all layers must have the same encoding\n");
+ return -EINVAL;
+ }
}
/*
--
2.50.1
