userns: Convert jffs2 to use kuid and kgid where appropriate

- General routine uid/gid conversion work
- When storing posix acls treat ACL_USER and ACL_GROUP separately
  so I can call from_kuid or from_kgid as appropriate.
- When reading posix acls treat ACL_USER and ACL_GROUP separately
  so I can call make_kuid or make_kgid as appropriate.

Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

4 files changed, 39 insertions, 23 deletions

diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c
index 42e4edc17a90..223283c30111 100644
--- a/fs/jffs2/acl.c
+++ b/fs/jffs2/acl.c
@@ -94,15 +94,23 @@ static struct posix_acl *jffs2_acl_from_medium(void *value, size_t size)
                         case ACL_MASK:
                         case ACL_OTHER:
                                 value += sizeof(struct jffs2_acl_entry_short);
-                                acl->a_entries[i].e_id = ACL_UNDEFINED_ID;
                                 break;
 
                         case ACL_USER:
+                                value += sizeof(struct jffs2_acl_entry);
+                                if (value > end)
+                                        goto fail;
+                                acl->a_entries[i].e_uid =
+                                        make_kuid(&init_user_ns,
+                                                  je32_to_cpu(entry->e_id));
+                                break;
                         case ACL_GROUP:
                                 value += sizeof(struct jffs2_acl_entry);
                                 if (value > end)
                                         goto fail;
-                                acl->a_entries[i].e_id = je32_to_cpu(entry->e_id);
+                                acl->a_entries[i].e_gid =
+                                        make_kgid(&init_user_ns,
+                                                  je32_to_cpu(entry->e_id));
                                 break;
 
                         default:
@@ -131,13 +139,19 @@ static void *jffs2_acl_to_medium(const struct posix_acl *acl, size_t *size)
         header->a_version = cpu_to_je32(JFFS2_ACL_VERSION);
         e = header + 1;
         for (i=0; i < acl->a_count; i++) {
+                const struct posix_acl_entry *acl_e = &acl->a_entries[i];
                 entry = e;
-                entry->e_tag = cpu_to_je16(acl->a_entries[i].e_tag);
-                entry->e_perm = cpu_to_je16(acl->a_entries[i].e_perm);
-                switch(acl->a_entries[i].e_tag) {
+                entry->e_tag = cpu_to_je16(acl_e->e_tag);
+                entry->e_perm = cpu_to_je16(acl_e->e_perm);
+                switch(acl_e->e_tag) {
                         case ACL_USER:
+                                entry->e_id = cpu_to_je32(
+                                        from_kuid(&init_user_ns, acl_e->e_uid));
+                                e += sizeof(struct jffs2_acl_entry);
+                                break;
                         case ACL_GROUP:
-                                entry->e_id = cpu_to_je32(acl->a_entries[i].e_id);
+                                entry->e_id = cpu_to_je32(
+                                        from_kgid(&init_user_ns, acl_e->e_gid));
                                 e += sizeof(struct jffs2_acl_entry);
                                 break;
 
diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c
index db3889ba8818..60ef3fb707ff 100644
--- a/fs/jffs2/file.c
+++ b/fs/jffs2/file.c
@@ -175,8 +175,8 @@ static int jffs2_write_begin(struct file *filp, struct address_space *mapping,
                 ri.ino = cpu_to_je32(f->inocache->ino);
                 ri.version = cpu_to_je32(++f->highest_version);
                 ri.mode = cpu_to_jemode(inode->i_mode);
-                ri.uid = cpu_to_je16(inode->i_uid);
-                ri.gid = cpu_to_je16(inode->i_gid);
+                ri.uid = cpu_to_je16(i_uid_read(inode));
+                ri.gid = cpu_to_je16(i_gid_read(inode));
                 ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
                 ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
                 ri.offset = cpu_to_je32(inode->i_size);
@@ -283,8 +283,8 @@ static int jffs2_write_end(struct file *filp, struct address_space *mapping,
         /* Set the fields that the generic jffs2_write_inode_range() code can't find */
         ri->ino = cpu_to_je32(inode->i_ino);
         ri->mode = cpu_to_jemode(inode->i_mode);
-        ri->uid = cpu_to_je16(inode->i_uid);
-        ri->gid = cpu_to_je16(inode->i_gid);
+        ri->uid = cpu_to_je16(i_uid_read(inode));
+        ri->gid = cpu_to_je16(i_gid_read(inode));
         ri->isize = cpu_to_je32((uint32_t)inode->i_size);
         ri->atime = ri->ctime = ri->mtime = cpu_to_je32(get_seconds());
 
diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c
index 3d3092eda811..fe3c0527545f 100644
--- a/fs/jffs2/fs.c
+++ b/fs/jffs2/fs.c
@@ -99,8 +99,10 @@ int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
         ri->ino = cpu_to_je32(inode->i_ino);
         ri->version = cpu_to_je32(++f->highest_version);
 
-        ri->uid = cpu_to_je16((ivalid & ATTR_UID)?iattr->ia_uid:inode->i_uid);
-        ri->gid = cpu_to_je16((ivalid & ATTR_GID)?iattr->ia_gid:inode->i_gid);
+        ri->uid = cpu_to_je16((ivalid & ATTR_UID)?
+                from_kuid(&init_user_ns, iattr->ia_uid):i_uid_read(inode));
+        ri->gid = cpu_to_je16((ivalid & ATTR_GID)?
+                from_kgid(&init_user_ns, iattr->ia_gid):i_gid_read(inode));
 
         if (ivalid & ATTR_MODE)
                 ri->mode = cpu_to_jemode(iattr->ia_mode);
@@ -147,8 +149,8 @@ int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
         inode->i_ctime = ITIME(je32_to_cpu(ri->ctime));
         inode->i_mtime = ITIME(je32_to_cpu(ri->mtime));
         inode->i_mode = jemode_to_cpu(ri->mode);
-        inode->i_uid = je16_to_cpu(ri->uid);
-        inode->i_gid = je16_to_cpu(ri->gid);
+        i_uid_write(inode, je16_to_cpu(ri->uid));
+        i_gid_write(inode, je16_to_cpu(ri->gid));
 
 
         old_metadata = f->metadata;
@@ -276,8 +278,8 @@ struct inode *jffs2_iget(struct super_block *sb, unsigned long ino)
                 return ERR_PTR(ret);
         }
         inode->i_mode = jemode_to_cpu(latest_node.mode);
-        inode->i_uid = je16_to_cpu(latest_node.uid);
-        inode->i_gid = je16_to_cpu(latest_node.gid);
+        i_uid_write(inode, je16_to_cpu(latest_node.uid));
+        i_gid_write(inode, je16_to_cpu(latest_node.gid));
         inode->i_size = je32_to_cpu(latest_node.isize);
         inode->i_atime = ITIME(je32_to_cpu(latest_node.atime));
         inode->i_mtime = ITIME(je32_to_cpu(latest_node.mtime));
@@ -440,14 +442,14 @@ struct inode *jffs2_new_inode (struct inode *dir_i, umode_t mode, struct jffs2_r
 
         memset(ri, 0, sizeof(*ri));
         /* Set OS-specific defaults for new inodes */
-        ri->uid = cpu_to_je16(current_fsuid());
+        ri->uid = cpu_to_je16(from_kuid(&init_user_ns, current_fsuid()));
 
         if (dir_i->i_mode & S_ISGID) {
-                ri->gid = cpu_to_je16(dir_i->i_gid);
+                ri->gid = cpu_to_je16(i_gid_read(dir_i));
                 if (S_ISDIR(mode))
                         mode |= S_ISGID;
         } else {
-                ri->gid = cpu_to_je16(current_fsgid());
+                ri->gid = cpu_to_je16(from_kgid(&init_user_ns, current_fsgid()));
         }
 
         /* POSIX ACLs have to be processed now, at least partly.
@@ -467,8 +469,8 @@ struct inode *jffs2_new_inode (struct inode *dir_i, umode_t mode, struct jffs2_r
         set_nlink(inode, 1);
         inode->i_ino = je32_to_cpu(ri->ino);
         inode->i_mode = jemode_to_cpu(ri->mode);
-        inode->i_gid = je16_to_cpu(ri->gid);
-        inode->i_uid = je16_to_cpu(ri->uid);
+        i_gid_write(inode, je16_to_cpu(ri->gid));
+        i_uid_write(inode, je16_to_cpu(ri->uid));
         inode->i_atime = inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
         ri->atime = ri->mtime = ri->ctime = cpu_to_je32(I_SEC(inode->i_mtime));
 
diff --git a/fs/jffs2/os-linux.h b/fs/jffs2/os-linux.h
index bcd983d7e7f9..d200a9b8fd5e 100644
--- a/fs/jffs2/os-linux.h
+++ b/fs/jffs2/os-linux.h
@@ -27,8 +27,8 @@ struct kvec;
 
 #define JFFS2_F_I_SIZE(f) (OFNI_EDONI_2SFFJ(f)->i_size)
 #define JFFS2_F_I_MODE(f) (OFNI_EDONI_2SFFJ(f)->i_mode)
-#define JFFS2_F_I_UID(f) (OFNI_EDONI_2SFFJ(f)->i_uid)
-#define JFFS2_F_I_GID(f) (OFNI_EDONI_2SFFJ(f)->i_gid)
+#define JFFS2_F_I_UID(f) (i_uid_read(OFNI_EDONI_2SFFJ(f)))
+#define JFFS2_F_I_GID(f) (i_gid_read(OFNI_EDONI_2SFFJ(f)))
 #define JFFS2_F_I_RDEV(f) (OFNI_EDONI_2SFFJ(f)->i_rdev)
 
 #define ITIME(sec) ((struct timespec){sec, 0})