LU-13717 sec: make client encryption compatible with ext4

[fs/lustre-release.git] / lustre / llite / xattr.c

diff --git a/lustre/llite/xattr.c b/lustre/llite/xattr.c
index 6325c8a..cc7839f 100644 (file)
--- a/lustre/llite/xattr.c
+++ b/lustre/llite/xattr.c
@@ -146,15 +146,14 @@ static int ll_xattr_set_common(const struct xattr_handler *handler,
                        RETURN(-EPERM);
        }
 
-       /* Setting LL_XATTR_NAME_ENCRYPTION_CONTEXT xattr is only allowed
-        * when defining an encryption policy on a directory, ie when it
-        * comes from ll_set_context().
-        * When new files/dirs are created in an encrypted dir, the xattr
-        * is set directly in the create request.
+       /* This check is required for compatibility with 2.14, in which
+        * encryption context is stored in security.c xattr.
+        * Setting the encryption context should only be possible by llcrypt
+        * when defining an encryption policy on a directory.
+        * When new files/dirs are created in an encrypted dir, the enc
+        * context is set directly in the create request.
         */
-       if (handler->flags == XATTR_SECURITY_T &&
-           !strcmp(name, "c") &&
-           !test_and_clear_bit(LLIF_SET_ENC_CTX, &ll_i2info(inode)->lli_flags))
+       if (handler->flags == XATTR_SECURITY_T && strcmp(name, "c") == 0)
                RETURN(-EPERM);
 
        fullname = kasprintf(GFP_KERNEL, "%s%s", xattr_prefix(handler), name);
@@ -379,18 +378,12 @@ int ll_xattr_list(struct inode *inode, const char *name, int type, void *buffer,
        int rc;
        ENTRY;
 
-       /* Getting LL_XATTR_NAME_ENCRYPTION_CONTEXT xattr is only allowed
-        * when it comes from ll_get_context(), ie when llcrypt needs to
-        * know the encryption context.
-        * Otherwise, any direct reading of this xattr returns -EPERM.
+       /* This check is required for compatibility with 2.14, in which
+        * encryption context is stored in security.c xattr. Accessing the
+        * encryption context should only be possible by llcrypt.
         */
-       if (type == XATTR_SECURITY_T &&
-           !strcmp(name, LL_XATTR_NAME_ENCRYPTION_CONTEXT)) {
-               struct ll_cl_context *lcc = ll_cl_find(inode);
-
-               if (!lcc || !lcc->lcc_getencctx)
-                       GOTO(out_xattr, rc = -EPERM);
-       }
+       if (type == XATTR_SECURITY_T && strcmp(name, "security.c") == 0)
+               GOTO(out_xattr, rc = -EPERM);
 
        if (sbi->ll_xattr_cache_enabled && type != XATTR_ACL_ACCESS_T &&
            (type != XATTR_SECURITY_T || strcmp(name, "security.selinux"))) {
@@ -623,7 +616,6 @@ static int ll_xattr_get(const struct xattr_handler *handler,
 
 ssize_t ll_listxattr(struct dentry *dentry, char *buffer, size_t size)
 {
-       struct inode *dir = d_inode(dentry->d_parent);
        struct inode *inode = dentry->d_inode;
        struct ll_sb_info *sbi = ll_i2sbi(inode);
        ktime_t kstart = ktime_get();
@@ -653,38 +645,37 @@ ssize_t ll_listxattr(struct dentry *dentry, char *buffer, size_t size)
        rem = rc;
 
        while (rem > 0) {
+               const struct xattr_handler *xh = get_xattr_type(xattr_name);
                bool hide_xattr = false;
 
-               /* Listing xattrs should not expose
-                * LL_XATTR_NAME_ENCRYPTION_CONTEXT xattr, unless it comes
-                * from llcrypt.
-                */
-               if (get_xattr_type(xattr_name)->flags == XATTR_SECURITY_T &&
-                   !strcmp(xattr_name, LL_XATTR_NAME_ENCRYPTION_CONTEXT)) {
-                       struct ll_cl_context *lcc = ll_cl_find(inode);
-
-                       if (!lcc || !lcc->lcc_getencctx)
-                               hide_xattr = true;
-               }
-
                /* Hide virtual project id xattr from the list when
                 * parent has the inherit flag and the same project id,
                 * so project id won't be messed up by copying the xattrs
                 * when mv to a tree with different project id.
                 */
-               if (get_xattr_type(xattr_name)->flags == XATTR_TRUSTED_T &&
+               if (xh && xh->flags == XATTR_TRUSTED_T &&
                    strcmp(xattr_name, XATTR_NAME_PROJID) == 0) {
-                       if (ll_i2info(inode)->lli_projid ==
-                                       ll_i2info(dir)->lli_projid &&
+                       struct inode *dir = d_inode(dentry->d_parent);
+
+                       if ((ll_i2info(inode)->lli_projid ==
+                            ll_i2info(dir)->lli_projid) &&
                            test_bit(LLIF_PROJECT_INHERIT,
                                     &ll_i2info(dir)->lli_flags))
                                hide_xattr = true;
+               } else if (xh && xh->flags == XATTR_SECURITY_T &&
+                          strcmp(xattr_name, "security.c") == 0) {
+                       /* Listing xattrs should not expose encryption
+                        * context. There is no handler defined for
+                        * XATTR_ENCRYPTION_PREFIX, so this test is just
+                        * needed for compatibility with 2.14, in which
+                        * encryption context is stored in security.c xattr.
+                        */
+                       hide_xattr = true;
                }
 
                len = strnlen(xattr_name, rem - 1) + 1;
                rem -= len;
-               if (!xattr_type_filter(sbi, hide_xattr ? NULL :
-                                      get_xattr_type(xattr_name))) {
+               if (!xattr_type_filter(sbi, hide_xattr ? NULL : xh)) {
                        /* Skip OK xattr type, leave it in buffer. */
                        xattr_name += len;
                        continue;