From 370e55ace59c2d3ed8f0ca933155030b9652e04f Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Fri, 16 Dec 2016 11:02:55 +0100 Subject: [PATCH] ovl: rename: simplify handling of lower/merged directory d_is_dir() is safe to call on a negative dentry. Use this fact to simplify handling of the lower or merged directories. Signed-off-by: Miklos Szeredi --- fs/overlayfs/dir.c | 30 ++++++++++++------------------ fs/overlayfs/overlayfs.h | 3 --- 2 files changed, 12 insertions(+), 21 deletions(-) diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 76b1edccbedd..69c3971a9992 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -761,13 +761,18 @@ static int ovl_rmdir(struct inode *dir, struct dentry *dentry) return ovl_do_remove(dentry, true); } +static bool ovl_type_merge_or_lower(struct dentry *dentry) +{ + enum ovl_path_type type = ovl_path_type(dentry); + + return OVL_TYPE_MERGE(type) || !OVL_TYPE_UPPER(type); +} + static int ovl_rename(struct inode *olddir, struct dentry *old, struct inode *newdir, struct dentry *new, unsigned int flags) { int err; - enum ovl_path_type old_type; - enum ovl_path_type new_type; struct dentry *old_upperdir; struct dentry *new_upperdir; struct dentry *olddentry; @@ -778,7 +783,7 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, bool cleanup_whiteout = false; bool overwrite = !(flags & RENAME_EXCHANGE); bool is_dir = d_is_dir(old); - bool new_is_dir = false; + bool new_is_dir = d_is_dir(new); struct dentry *opaquedir = NULL; const struct cred *old_cred = NULL; @@ -789,22 +794,11 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, flags &= ~RENAME_NOREPLACE; /* Don't copy up directory trees */ - old_type = ovl_path_type(old); err = -EXDEV; - if (OVL_TYPE_MERGE_OR_LOWER(old_type) && is_dir) + if (is_dir && ovl_type_merge_or_lower(old)) + goto out; + if (!overwrite && new_is_dir && ovl_type_merge_or_lower(new)) goto out; - - if (new->d_inode) { - if (d_is_dir(new)) - new_is_dir = true; - - new_type = ovl_path_type(new); - err = -EXDEV; - if (!overwrite && OVL_TYPE_MERGE_OR_LOWER(new_type) && new_is_dir) - goto out; - } else { - new_type = __OVL_PATH_UPPER; - } err = ovl_want_write(old); if (err) @@ -828,7 +822,7 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, old_cred = ovl_override_creds(old->d_sb); - if (overwrite && OVL_TYPE_MERGE_OR_LOWER(new_type) && new_is_dir) { + if (overwrite && new_is_dir && ovl_type_merge_or_lower(new)) { opaquedir = ovl_check_empty_and_clear(new); err = PTR_ERR(opaquedir); if (IS_ERR(opaquedir)) { diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index f183d1db78bd..db28512165c5 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -18,9 +18,6 @@ enum ovl_path_type { #define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER) #define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE) -#define OVL_TYPE_MERGE_OR_LOWER(type) \ - (OVL_TYPE_MERGE(type) || !OVL_TYPE_UPPER(type)) - #define OVL_XATTR_PREFIX XATTR_TRUSTED_PREFIX "overlay." #define OVL_XATTR_OPAQUE OVL_XATTR_PREFIX "opaque" -- 2.20.1