diff options
Diffstat (limited to 'fs/overlayfs/dir.c')
-rw-r--r-- | fs/overlayfs/dir.c | 83 |
1 files changed, 53 insertions, 30 deletions
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 692ceda3bc21..b3fc0a35bf62 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -167,7 +167,7 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode, struct dentry *newdentry; int err; - mutex_lock_nested(&udir->i_mutex, I_MUTEX_PARENT); + inode_lock_nested(udir, I_MUTEX_PARENT); newdentry = lookup_one_len(dentry->d_name.name, upperdir, dentry->d_name.len); err = PTR_ERR(newdentry); @@ -185,7 +185,7 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode, out_dput: dput(newdentry); out_unlock: - mutex_unlock(&udir->i_mutex); + inode_unlock(udir); return err; } @@ -258,9 +258,9 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry, if (err) goto out_cleanup; - mutex_lock(&opaquedir->d_inode->i_mutex); + inode_lock(opaquedir->d_inode); err = ovl_set_attr(opaquedir, &stat); - mutex_unlock(&opaquedir->d_inode->i_mutex); + inode_unlock(opaquedir->d_inode); if (err) goto out_cleanup; @@ -596,21 +596,25 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir) { struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); struct inode *dir = upperdir->d_inode; - struct dentry *upper = ovl_dentry_upper(dentry); + struct dentry *upper; int err; - mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT); + inode_lock_nested(dir, I_MUTEX_PARENT); + upper = lookup_one_len(dentry->d_name.name, upperdir, + dentry->d_name.len); + err = PTR_ERR(upper); + if (IS_ERR(upper)) + goto out_unlock; + err = -ESTALE; - if (upper->d_parent == upperdir) { - /* Don't let d_delete() think it can reset d_inode */ - dget(upper); + if (upper == ovl_dentry_upper(dentry)) { if (is_dir) err = vfs_rmdir(dir, upper); else err = vfs_unlink(dir, upper, NULL); - dput(upper); ovl_dentry_version_inc(dentry->d_parent); } + dput(upper); /* * Keeping this dentry hashed would mean having to release @@ -618,8 +622,10 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir) * sole user of this dentry. Too tricky... Just unhash for * now. */ - d_drop(dentry); - mutex_unlock(&dir->i_mutex); + if (!err) + d_drop(dentry); +out_unlock: + inode_unlock(dir); return err; } @@ -713,7 +719,6 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old, struct dentry *trap; bool old_opaque; bool new_opaque; - bool new_create = false; bool cleanup_whiteout = false; bool overwrite = !(flags & RENAME_EXCHANGE); bool is_dir = d_is_dir(old); @@ -839,29 +844,38 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old, trap = lock_rename(new_upperdir, old_upperdir); - olddentry = ovl_dentry_upper(old); - newdentry = ovl_dentry_upper(new); - if (newdentry) { + + olddentry = lookup_one_len(old->d_name.name, old_upperdir, + old->d_name.len); + err = PTR_ERR(olddentry); + if (IS_ERR(olddentry)) + goto out_unlock; + + err = -ESTALE; + if (olddentry != ovl_dentry_upper(old)) + goto out_dput_old; + + newdentry = lookup_one_len(new->d_name.name, new_upperdir, + new->d_name.len); + err = PTR_ERR(newdentry); + if (IS_ERR(newdentry)) + goto out_dput_old; + + err = -ESTALE; + if (ovl_dentry_upper(new)) { if (opaquedir) { - newdentry = opaquedir; - opaquedir = NULL; + if (newdentry != opaquedir) + goto out_dput; } else { - dget(newdentry); + if (newdentry != ovl_dentry_upper(new)) + goto out_dput; } } else { - new_create = true; - newdentry = lookup_one_len(new->d_name.name, new_upperdir, - new->d_name.len); - err = PTR_ERR(newdentry); - if (IS_ERR(newdentry)) - goto out_unlock; + if (!d_is_negative(newdentry) && + (!new_opaque || !ovl_is_whiteout(newdentry))) + goto out_dput; } - err = -ESTALE; - if (olddentry->d_parent != old_upperdir) - goto out_dput; - if (newdentry->d_parent != new_upperdir) - goto out_dput; if (olddentry == trap) goto out_dput; if (newdentry == trap) @@ -903,6 +917,13 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old, if (!overwrite && new_is_dir && !old_opaque && new_opaque) ovl_remove_opaque(newdentry); + /* + * Old dentry now lives in different location. Dentries in + * lowerstack are stale. We cannot drop them here because + * access to them is lockless. This could be only pure upper + * or opaque directory - numlower is zero. Or upper non-dir + * entry - its pureness is tracked by flag opaque. + */ if (old_opaque != new_opaque) { ovl_dentry_set_opaque(old, new_opaque); if (!overwrite) @@ -917,6 +938,8 @@ static int ovl_rename2(struct inode *olddir, struct dentry *old, out_dput: dput(newdentry); +out_dput_old: + dput(olddentry); out_unlock: unlock_rename(new_upperdir, old_upperdir); out_revert_creds: |