fs: port i_{g,u}id_{needs_}update() to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>

diff --git a/fs/attr.c b/fs/attr.c
index 2cadd055dbf260ef5580d9fbbf3ae1cfde108a98..bbb9118c6c8bc3fab47c500d1f629ef3b92d1e43 100644 (file)
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -311,8 +311,8 @@ void setattr_copy(struct mnt_idmap *idmap, struct inode *inode,
        struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
        unsigned int ia_valid = attr->ia_valid;
 
-       i_uid_update(mnt_userns, attr, inode);
-       i_gid_update(mnt_userns, attr, inode);
+       i_uid_update(idmap, attr, inode);
+       i_gid_update(idmap, attr, inode);
        if (ia_valid & ATTR_ATIME)
                inode->i_atime = attr->ia_atime;
        if (ia_valid & ATTR_MTIME)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 8b9b1cb6e3ab75e82114c2747237bf715639f693..be664dc9b991774b5ae29528c45ed5d1ade687b9 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5442,7 +5442,6 @@ int ext4_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
        int orphan = 0;
        const unsigned int ia_valid = attr->ia_valid;
        bool inc_ivers = true;
-       struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 
        if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
                return -EIO;
@@ -5473,8 +5472,8 @@ int ext4_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
                        return error;
        }
 
-       if (i_uid_needs_update(mnt_userns, attr, inode) ||
-           i_gid_needs_update(mnt_userns, attr, inode)) {
+       if (i_uid_needs_update(idmap, attr, inode) ||
+           i_gid_needs_update(idmap, attr, inode)) {
                handle_t *handle;
 
                /* (user+group)*(old+new) structure, inode write (sb,
@@ -5500,8 +5499,8 @@ int ext4_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
                }
                /* Update corresponding info in inode so that everything is in
                 * one transaction */
-               i_uid_update(mnt_userns, attr, inode);
-               i_gid_update(mnt_userns, attr, inode);
+               i_uid_update(idmap, attr, inode);
+               i_gid_update(idmap, attr, inode);
                error = ext4_mark_inode_dirty(handle, inode);
                ext4_journal_stop(handle);
                if (unlikely(error)) {

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 262c831e3450ab3017a772fa3be183d089c87be9..577c1613b6cfa6b696484f3c723acf6c263f4818 100644 (file)
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -909,8 +909,8 @@ static void __setattr_copy(struct mnt_idmap *idmap,
        unsigned int ia_valid = attr->ia_valid;
        struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
 
-       i_uid_update(mnt_userns, attr, inode);
-       i_gid_update(mnt_userns, attr, inode);
+       i_uid_update(idmap, attr, inode);
+       i_gid_update(idmap, attr, inode);
        if (ia_valid & ATTR_ATIME)
                inode->i_atime = attr->ia_atime;
        if (ia_valid & ATTR_MTIME)
@@ -934,7 +934,6 @@ static void __setattr_copy(struct mnt_idmap *idmap,
 int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
                 struct iattr *attr)
 {
-       struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
        struct inode *inode = d_inode(dentry);
        int err;
 
@@ -970,8 +969,8 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
                if (err)
                        return err;
        }
-       if (i_uid_needs_update(mnt_userns, attr, inode) ||
-           i_gid_needs_update(mnt_userns, attr, inode)) {
+       if (i_uid_needs_update(idmap, attr, inode) ||
+           i_gid_needs_update(idmap, attr, inode)) {
                f2fs_lock_op(F2FS_I_SB(inode));
                err = dquot_transfer(idmap, inode, attr);
                if (err) {
@@ -984,8 +983,8 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
                 * update uid/gid under lock_op(), so that dquot and inode can
                 * be updated atomically.
                 */
-               i_uid_update(mnt_userns, attr, inode);
-               i_gid_update(mnt_userns, attr, inode);
+               i_uid_update(idmap, attr, inode);
+               i_gid_update(idmap, attr, inode);
                f2fs_mark_inode_dirty_sync(inode, true);
                f2fs_unlock_op(F2FS_I_SB(inode));
        }

diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 6ae106c0f14671ff9f6633be02863158f9e011f0..207434a854f39ce62e81d10cd5bcf837d76ce98e 100644 (file)
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -2097,7 +2097,7 @@ int dquot_transfer(struct mnt_idmap *idmap, struct inode *inode,
        if (!dquot_active(inode))
                return 0;
 
-       if (i_uid_needs_update(mnt_userns, iattr, inode)) {
+       if (i_uid_needs_update(idmap, iattr, inode)) {
                kuid_t kuid = from_vfsuid(mnt_userns, i_user_ns(inode),
                                          iattr->ia_vfsuid);
 
@@ -2111,7 +2111,7 @@ int dquot_transfer(struct mnt_idmap *idmap, struct inode *inode,
                }
                transfer_to[USRQUOTA] = dquot;
        }
-       if (i_gid_needs_update(mnt_userns, iattr, inode)) {
+       if (i_gid_needs_update(idmap, iattr, inode)) {
                kgid_t kgid = from_vfsgid(mnt_userns, i_user_ns(inode),
                                          iattr->ia_vfsgid);
 

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 94c2f4aa675a2def1c47a1244cd9de2c520d8e95..c6284fb9e1362db1d8886cfd368fd9a8a56e10dc 100644 (file)
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -720,12 +720,12 @@ xfs_setattr_nonsize(
         * also.
         */
        if (XFS_IS_UQUOTA_ON(mp) &&
-           i_uid_needs_update(mnt_userns, iattr, inode)) {
+           i_uid_needs_update(idmap, iattr, inode)) {
                ASSERT(udqp);
                old_udqp = xfs_qm_vop_chown(tp, ip, &ip->i_udquot, udqp);
        }
        if (XFS_IS_GQUOTA_ON(mp) &&
-           i_gid_needs_update(mnt_userns, iattr, inode)) {
+           i_gid_needs_update(idmap, iattr, inode)) {
                ASSERT(xfs_has_pquotino(mp) || !XFS_IS_PQUOTA_ON(mp));
                ASSERT(gdqp);
                old_gdqp = xfs_qm_vop_chown(tp, ip, &ip->i_gdquot, gdqp);

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 696540a8618347a58741152e23baf1855a19b23c..3611d459bf8869f021ab1797f14a8fd47f904333 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1647,7 +1647,7 @@ static inline vfsuid_t i_uid_into_vfsuid(struct user_namespace *mnt_userns,
 
 /**
  * i_uid_needs_update - check whether inode's i_uid needs to be updated
- * @mnt_userns: user namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @attr: the new attributes of @inode
  * @inode: the inode to update
  *
@@ -1656,10 +1656,12 @@ static inline vfsuid_t i_uid_into_vfsuid(struct user_namespace *mnt_userns,
  *
  * Return: true if @inode's i_uid field needs to be updated, false if not.
  */
-static inline bool i_uid_needs_update(struct user_namespace *mnt_userns,
+static inline bool i_uid_needs_update(struct mnt_idmap *idmap,
                                      const struct iattr *attr,
                                      const struct inode *inode)
 {
+       struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
+
        return ((attr->ia_valid & ATTR_UID) &&
                !vfsuid_eq(attr->ia_vfsuid,
                           i_uid_into_vfsuid(mnt_userns, inode)));
@@ -1667,17 +1669,19 @@ static inline bool i_uid_needs_update(struct user_namespace *mnt_userns,
 
 /**
  * i_uid_update - update @inode's i_uid field
- * @mnt_userns: user namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @attr: the new attributes of @inode
  * @inode: the inode to update
  *
  * Safely update @inode's i_uid field translating the vfsuid of any idmapped
  * mount into the filesystem kuid.
  */
-static inline void i_uid_update(struct user_namespace *mnt_userns,
+static inline void i_uid_update(struct mnt_idmap *idmap,
                                const struct iattr *attr,
                                struct inode *inode)
 {
+       struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
+
        if (attr->ia_valid & ATTR_UID)
                inode->i_uid = from_vfsuid(mnt_userns, i_user_ns(inode),
                                           attr->ia_vfsuid);
@@ -1699,7 +1703,7 @@ static inline vfsgid_t i_gid_into_vfsgid(struct user_namespace *mnt_userns,
 
 /**
  * i_gid_needs_update - check whether inode's i_gid needs to be updated
- * @mnt_userns: user namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @attr: the new attributes of @inode
  * @inode: the inode to update
  *
@@ -1708,10 +1712,12 @@ static inline vfsgid_t i_gid_into_vfsgid(struct user_namespace *mnt_userns,
  *
  * Return: true if @inode's i_gid field needs to be updated, false if not.
  */
-static inline bool i_gid_needs_update(struct user_namespace *mnt_userns,
+static inline bool i_gid_needs_update(struct mnt_idmap *idmap,
                                      const struct iattr *attr,
                                      const struct inode *inode)
 {
+       struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
+
        return ((attr->ia_valid & ATTR_GID) &&
                !vfsgid_eq(attr->ia_vfsgid,
                           i_gid_into_vfsgid(mnt_userns, inode)));
@@ -1719,17 +1725,19 @@ static inline bool i_gid_needs_update(struct user_namespace *mnt_userns,
 
 /**
  * i_gid_update - update @inode's i_gid field
- * @mnt_userns: user namespace of the mount the inode was found from
+ * @idmap: idmap of the mount the inode was found from
  * @attr: the new attributes of @inode
  * @inode: the inode to update
  *
  * Safely update @inode's i_gid field translating the vfsgid of any idmapped
  * mount into the filesystem kgid.
  */
-static inline void i_gid_update(struct user_namespace *mnt_userns,
+static inline void i_gid_update(struct mnt_idmap *idmap,
                                const struct iattr *attr,
                                struct inode *inode)
 {
+       struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
+
        if (attr->ia_valid & ATTR_GID)
                inode->i_gid = from_vfsgid(mnt_userns, i_user_ns(inode),
                                           attr->ia_vfsgid);

diff --git a/include/linux/quotaops.h b/include/linux/quotaops.h
index 5f6744b3ceac5879515a0f1a8b7ed6d52bf8d212..11a4becff3a983247a8653f3f68fe000739f026f 100644 (file)
--- a/include/linux/quotaops.h
+++ b/include/linux/quotaops.h
@@ -23,10 +23,9 @@ static inline struct quota_info *sb_dqopt(struct super_block *sb)
 static inline bool is_quota_modification(struct mnt_idmap *idmap,
                                         struct inode *inode, struct iattr *ia)
 {
-       struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
        return ((ia->ia_valid & ATTR_SIZE) ||
-               i_uid_needs_update(mnt_userns, ia, inode) ||
-               i_gid_needs_update(mnt_userns, ia, inode));
+               i_uid_needs_update(idmap, ia, inode) ||
+               i_gid_needs_update(idmap, ia, inode));
 }
 
 #if defined(CONFIG_QUOTA)

diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c
index 4e5adddb3577bc78a4180e8a8a232a975c788fd3..cf24c5255583cb7521582d46f61b951c82b33cc9 100644 (file)
--- a/security/integrity/evm/evm_main.c
+++ b/security/integrity/evm/evm_main.c
@@ -783,11 +783,10 @@ static int evm_attr_change(struct mnt_idmap *idmap,
                           struct dentry *dentry, struct iattr *attr)
 {
        struct inode *inode = d_backing_inode(dentry);
-       struct user_namespace *mnt_userns = mnt_idmap_owner(idmap);
        unsigned int ia_valid = attr->ia_valid;
 
-       if (!i_uid_needs_update(mnt_userns, attr, inode) &&
-           !i_gid_needs_update(mnt_userns, attr, inode) &&
+       if (!i_uid_needs_update(idmap, attr, inode) &&
+           !i_gid_needs_update(idmap, attr, inode) &&
            (!(ia_valid & ATTR_MODE) || attr->ia_mode == inode->i_mode))
                return 0;