Enable mounting filesystems with case-insensitive dentries in order to
support such filesystems in overlayfs.
Signed-off-by: André Almeida <andrealmeid@xxxxxxxxxx>
---
Changes from v3:
- Move this patch to be ealier in the series
- Split this patch with the ovl_lookup_single() restriction patch
---
fs/overlayfs/ovl_entry.h | 1 +
fs/overlayfs/params.c | 15 ++++++++++++---
fs/overlayfs/params.h | 1 +
fs/overlayfs/util.c | 8 ++++----
4 files changed, 18 insertions(+), 7 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..17d2354ba88d92e1d9653e8cb1382d860a7329c5 100644
--- a/fs/overlayfs/params.c
+++ b/fs/overlayfs/params.c
@@ -277,16 +277,25 @@ static int ovl_mount_dir_check(struct fs_context *fc, const struct path *path,
enum ovl_opt layer, const char *name, bool upper)
{
struct ovl_fs_context *ctx = fc->fs_private;
+ struct ovl_fs *ofs = fc->s_fs_info;
+ bool is_casefolded = ovl_dentry_casefolded(path->dentry);
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);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index a33115e7384c129c543746326642813add63f060..7a6ee058568283453350153c1720c35e11ad4d1b 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -210,11 +210,11 @@ bool ovl_dentry_weird(struct dentry *dentry)
return true;
/*
- * Allow filesystems that are case-folding capable but deny composing
- * ovl stack from case-folded directories.
+ * Exceptionally for casefold dentries, we accept that they have their
+ * own hash and compare operations
*/
- if (sb_has_encoding(dentry->d_sb))
- return IS_CASEFOLDED(d_inode(dentry));
+ if (ovl_dentry_casefolded(dentry))
+ return false;
return dentry->d_flags & (DCACHE_OP_HASH | DCACHE_OP_COMPARE);
}
--
2.50.1
