Now that posix acls have a proper api us it to copy them.
All filesystems that can serve as lower or upper layers for overlayfs
have gained support for the new posix acl api in previous patches.
So switch all internal overlayfs codepaths for copying posix acls to the
new posix acl api.
Signed-off-by: Christian Brauner (Microsoft) <brauner@xxxxxxxxxx>
---
fs/overlayfs/copy_up.c | 9 +++++++++
fs/overlayfs/dir.c | 20 ++-----------------
fs/overlayfs/inode.c | 4 ++--
fs/overlayfs/overlayfs.h | 9 +++++++++
fs/overlayfs/super.c | 6 ++----
fs/overlayfs/util.c | 42 ++++++++++++++++++++++++++++++++++++++++
fs/xattr.c | 6 ------
include/linux/xattr.h | 6 ++++++
8 files changed, 72 insertions(+), 30 deletions(-)
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index fdde6c56cc3d..93e575021ca1 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -93,6 +93,15 @@ int ovl_copy_xattr(struct super_block *sb, struct path *oldpath, struct dentry *
error = 0;
continue; /* Discard */
}
+
+ if (is_posix_acl_xattr(name)) {
+ error = ovl_copy_acl(OVL_FS(sb), oldpath, new, name);
+ if (!error)
+ continue;
+ /* POSIX ACLs must be copied. */
+ break;
+ }
+
retry:
size = ovl_do_getxattr(oldpath, name, value, value_size);
if (size == -ERANGE)
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 0e817ebce92c..cbb569d5d234 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -435,28 +435,12 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
}
static int ovl_set_upper_acl(struct ovl_fs *ofs, struct dentry *upperdentry,
- const char *name, const struct posix_acl *acl)
+ const char *acl_name, struct posix_acl *acl)
{
- void *buffer;
- size_t size;
- int err;
-
if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !acl)
return 0;
- size = posix_acl_xattr_size(acl->a_count);
- buffer = kmalloc(size, GFP_KERNEL);
- if (!buffer)
- return -ENOMEM;
-
- err = posix_acl_to_xattr(&init_user_ns, acl, buffer, size);
- if (err < 0)
- goto out_free;
-
- err = ovl_do_setxattr(ofs, upperdentry, name, buffer, size, XATTR_CREATE);
-out_free:
- kfree(buffer);
- return err;
+ return ovl_do_set_acl(ofs, upperdentry, acl_name, acl);
}
static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index b0a19f9deaf1..c6cb62daa8c2 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -550,8 +550,8 @@ struct posix_acl *ovl_get_inode_acl(struct inode *inode, int type, bool rcu)
return clone;
}
-static struct posix_acl *ovl_get_acl_path(const struct path *path,
- const char *acl_name)
+struct posix_acl *ovl_get_acl_path(const struct path *path,
+ const char *acl_name)
{
struct posix_acl *real_acl, *clone;
struct user_namespace *mnt_userns;
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index b2645baeba2f..3528e5631cb2 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -436,6 +436,8 @@ static inline bool ovl_check_origin_xattr(struct ovl_fs *ofs,
int ovl_check_setxattr(struct ovl_fs *ofs, struct dentry *upperdentry,
enum ovl_xattr ox, const void *value, size_t size,
int xerr);
+int ovl_copy_acl(struct ovl_fs *ofs, const struct path *path,
+ struct dentry *dentry, const char *acl_name);
int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry);
bool ovl_inuse_trylock(struct dentry *dentry);
void ovl_inuse_unlock(struct dentry *dentry);
@@ -614,10 +616,17 @@ int ovl_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
void ovl_idmap_posix_acl(struct inode *realinode,
struct user_namespace *mnt_userns,
struct posix_acl *acl);
+struct posix_acl *ovl_get_acl_path(const struct path *path,
+ const char *acl_name);
#else
#define ovl_get_inode_acl NULL
#define ovl_get_acl NULL
#define ovl_set_acl NULL
+static inline struct posix_acl *ovl_get_acl_path(const struct path *path,
+ const char *acl_name)
+{
+ return NULL;
+}
#endif
int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags);
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 5da771b218d1..8a13319db1d3 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -812,13 +812,11 @@ static struct dentry *ovl_workdir_create(struct ovl_fs *ofs,
* allowed as upper are limited to "normal" ones, where checking
* for the above two errors is sufficient.
*/
- err = ovl_do_removexattr(ofs, work,
- XATTR_NAME_POSIX_ACL_DEFAULT);
+ err = ovl_do_remove_acl(ofs, work, XATTR_NAME_POSIX_ACL_DEFAULT);
if (err && err != -ENODATA && err != -EOPNOTSUPP)
goto out_dput;
- err = ovl_do_removexattr(ofs, work,
- XATTR_NAME_POSIX_ACL_ACCESS);
+ err = ovl_do_remove_acl(ofs, work, XATTR_NAME_POSIX_ACL_ACCESS);
if (err && err != -ENODATA && err != -EOPNOTSUPP)
goto out_dput;
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 87f811c089e4..0246babce4d2 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -1117,3 +1117,45 @@ void ovl_copyattr(struct inode *inode)
inode->i_ctime = realinode->i_ctime;
i_size_write(inode, i_size_read(realinode));
}
+
+int ovl_copy_acl(struct ovl_fs *ofs, const struct path *path,
+ struct dentry *dentry, const char *acl_name)
+{
+ int err;
+ struct posix_acl *real_acl = NULL;
+
+ real_acl = ovl_get_acl_path(path, acl_name);
+ if (!real_acl)
+ return 0;
+
+ if (IS_ERR(real_acl)) {
+ err = PTR_ERR(real_acl);
+ if (err == -ENODATA || err == -EOPNOTSUPP)
+ return 0;
+ return err;
+ }
+
+ /*
+ * If we didn't have to create a copy already because @path was on an
+ * idmapped mount we need to do so if the upper layer is so we don't
+ * alter the POSIX ACLs of the filesystem we retrieved them from.
+ */
+ if (!is_idmapped_mnt(path->mnt) && is_idmapped_mnt(ovl_upper_mnt(ofs))) {
+ struct posix_acl *clone;
+
+ clone = posix_acl_clone(real_acl, GFP_KERNEL);
+ if (!clone) {
+ err = -ENOMEM;
+ goto out;
+ }
+ /* release original acl */
+ posix_acl_release(real_acl);
+ real_acl = clone;
+ }
+
+ err = ovl_do_set_acl(ofs, dentry, acl_name, real_acl);
+out:
+ /* release original or cloned acl */
+ posix_acl_release(real_acl);
+ return err;
+}
diff --git a/fs/xattr.c b/fs/xattr.c
index e16d7bde4935..0b9a84921c4d 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -281,12 +281,6 @@ __vfs_setxattr_locked(struct user_namespace *mnt_userns, struct dentry *dentry,
}
EXPORT_SYMBOL_GPL(__vfs_setxattr_locked);
-static inline bool is_posix_acl_xattr(const char *name)
-{
- return (strcmp(name, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
- (strcmp(name, XATTR_NAME_POSIX_ACL_DEFAULT) == 0);
-}
-
int
vfs_setxattr(struct user_namespace *mnt_userns, struct dentry *dentry,
const char *name, const void *value, size_t size, int flags)
diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 8267e547e631..d44d59177026 100644
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -22,6 +22,12 @@
struct inode;
struct dentry;
+static inline bool is_posix_acl_xattr(const char *name)
+{
+ return (strcmp(name, XATTR_NAME_POSIX_ACL_ACCESS) == 0) ||
+ (strcmp(name, XATTR_NAME_POSIX_ACL_DEFAULT) == 0);
+}
+
/*
* struct xattr_handler: When @name is set, match attributes with exactly that
* name. When @prefix is set instead, match attributes with that prefix and
--
2.34.1
