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 Signed-off-by: André Almeida --- 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