tmpfs: listxattr should include POSIX ACL xattrs

When a file on tmpfs has an ACL or a Default ACL, listxattr should include the
corresponding xattr name.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: linux-mm@kvack.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index f97e1f7..16405ae 100644 (file)
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -230,7 +230,7 @@ ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size)
        if (!attrs)
                return -ENOMEM;
 
-       return simple_xattr_list(&attrs->xattrs, buf, size);
+       return simple_xattr_list(d_inode(dentry), &attrs->xattrs, buf, size);
 }
 
 static inline void set_default_inode_attr(struct inode *inode, umode_t mode)

diff --git a/fs/xattr.c b/fs/xattr.c
index 4ef8b37..c3af6c9 100644 (file)
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -921,38 +921,59 @@ static bool xattr_is_trusted(const char *name)
        return !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN);
 }
 
+static int xattr_list_one(char **buffer, ssize_t *remaining_size,
+                         const char *name)
+{
+       size_t len = strlen(name) + 1;
+       if (*buffer) {
+               if (*remaining_size < len)
+                       return -ERANGE;
+               memcpy(*buffer, name, len);
+               *buffer += len;
+       }
+       *remaining_size -= len;
+       return 0;
+}
+
 /*
  * xattr LIST operation for in-memory/pseudo filesystems
  */
-ssize_t simple_xattr_list(struct simple_xattrs *xattrs, char *buffer,
-                         size_t size)
+ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs,
+                         char *buffer, size_t size)
 {
        bool trusted = capable(CAP_SYS_ADMIN);
        struct simple_xattr *xattr;
-       size_t used = 0;
+       ssize_t remaining_size = size;
+       int err;
+
+#ifdef CONFIG_FS_POSIX_ACL
+       if (inode->i_acl) {
+               err = xattr_list_one(&buffer, &remaining_size,
+                                    XATTR_NAME_POSIX_ACL_ACCESS);
+               if (err)
+                       return err;
+       }
+       if (inode->i_default_acl) {
+               err = xattr_list_one(&buffer, &remaining_size,
+                                    XATTR_NAME_POSIX_ACL_DEFAULT);
+               if (err)
+                       return err;
+       }
+#endif
 
        spin_lock(&xattrs->lock);
        list_for_each_entry(xattr, &xattrs->head, list) {
-               size_t len;
-
                /* skip "trusted." attributes for unprivileged callers */
                if (!trusted && xattr_is_trusted(xattr->name))
                        continue;
 
-               len = strlen(xattr->name) + 1;
-               used += len;
-               if (buffer) {
-                       if (size < used) {
-                               used = -ERANGE;
-                               break;
-                       }
-                       memcpy(buffer, xattr->name, len);
-                       buffer += len;
-               }
+               err = xattr_list_one(&buffer, &remaining_size, xattr->name);
+               if (err)
+                       return err;
        }
        spin_unlock(&xattrs->lock);
 
-       return used;
+       return size - remaining_size;
 }
 
 /*

diff --git a/include/linux/xattr.h b/include/linux/xattr.h
index 4dd40cb..d23ce8e 100644 (file)
--- a/include/linux/xattr.h
+++ b/include/linux/xattr.h
@@ -104,7 +104,8 @@ int simple_xattr_get(struct simple_xattrs *xattrs, const char *name,
                     void *buffer, size_t size);
 int simple_xattr_set(struct simple_xattrs *xattrs, const char *name,
                     const void *value, size_t size, int flags);
-ssize_t simple_xattr_list(struct simple_xattrs *xattrs, char *buffer, size_t size);
+ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, char *buffer,
+                         size_t size);
 void simple_xattr_list_add(struct simple_xattrs *xattrs,
                           struct simple_xattr *new_xattr);
 

diff --git a/mm/shmem.c b/mm/shmem.c
index fdfe6c8..297390f 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2606,7 +2606,7 @@ static const struct xattr_handler *shmem_xattr_handlers[] = {
 static ssize_t shmem_listxattr(struct dentry *dentry, char *buffer, size_t size)
 {
        struct shmem_inode_info *info = SHMEM_I(d_inode(dentry));
-       return simple_xattr_list(&info->xattrs, buffer, size);
+       return simple_xattr_list(d_inode(dentry), &info->xattrs, buffer, size);
 }
 #endif /* CONFIG_TMPFS_XATTR */