Prepare for mounting layers with case-insensitive dentries in order to
supporting such layers in overlayfs, while enforcing uniform casefold
layers.
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>
---
fs/overlayfs/ovl_entry.h | 1 +
fs/overlayfs/params.c | 15 ++++++++++++---
fs/overlayfs/params.h | 1 +
3 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index 4c1bae935ced274f93a0d23fe10d34455e226ec4..1d4828dbcf7ac4ba9657221e601bbf79d970d225 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -91,6 +91,7 @@ struct ovl_fs {
struct mutex whiteout_lock;
/* r/o snapshot of upperdir sb's only taken on volatile mounts */
errseq_t errseq;
+ bool casefold;
};
/* Number of lower layers, not including data-only layers */
diff --git a/fs/overlayfs/params.c b/fs/overlayfs/params.c
index f4e7fff909ac49e2f8c58a76273426c1158a7472..63b7346c5ee1c127a9c33b12c3704aa035ff88cf 100644
--- a/fs/overlayfs/params.c
+++ b/fs/overlayfs/params.c
@@ -276,17 +276,26 @@ static int ovl_mount_dir(const char *name, struct path *path)
static int ovl_mount_dir_check(struct fs_context *fc, const struct path *path,
enum ovl_opt layer, const char *name, bool upper)
{
+ bool is_casefolded = ovl_dentry_casefolded(path->dentry);
struct ovl_fs_context *ctx = fc->fs_private;
+ struct ovl_fs *ofs = fc->s_fs_info;
if (!d_is_dir(path->dentry))
return invalfc(fc, "%s is not a directory", name);
/*
* Allow filesystems that are case-folding capable but deny composing
- * ovl stack from case-folded directories.
+ * ovl stack from inconsistent case-folded directories.
*/
- if (ovl_dentry_casefolded(path->dentry))
- return invalfc(fc, "case-insensitive directory on %s not supported", name);
+ if (!ctx->casefold_set) {
+ ofs->casefold = is_casefolded;
+ ctx->casefold_set = true;
+ }
+
+ if (ofs->casefold != is_casefolded) {
+ return invalfc(fc, "case-%ssensitive directory on %s is inconsistent",
+ is_casefolded ? "in" : "", name);
+ }
if (ovl_dentry_weird(path->dentry))
return invalfc(fc, "filesystem on %s not supported", name);
diff --git a/fs/overlayfs/params.h b/fs/overlayfs/params.h
index c96d939820211ddc63e265670a2aff60d95eec49..ffd53cdd84827cce827e8852f2de545f966ce60d 100644
--- a/fs/overlayfs/params.h
+++ b/fs/overlayfs/params.h
@@ -33,6 +33,7 @@ struct ovl_fs_context {
struct ovl_opt_set set;
struct ovl_fs_context_layer *lower;
char *lowerdir_all; /* user provided lowerdir string */
+ bool casefold_set;
};
int ovl_init_fs_context(struct fs_context *fc);
--
2.50.1
