LU-12275 sec: O_DIRECT for encrypted file

[fs/lustre-release.git] / lustre / llite / rw26.c

diff --git a/lustre/llite/rw26.c b/lustre/llite/rw26.c
index 94b2436..65024f2 100644 (file)
--- a/lustre/llite/rw26.c
+++ b/lustre/llite/rw26.c
@@ -308,6 +308,7 @@ ll_direct_rw_pages(const struct lu_env *env, struct cl_io *io, size_t size,
        int io_pages    = 0;
        size_t page_size = cl_page_size(obj);
        int i;
+       pgoff_t index = offset >> PAGE_SHIFT;
        ssize_t rc = 0;
 
        ENTRY;
@@ -329,6 +330,28 @@ ll_direct_rw_pages(const struct lu_env *env, struct cl_io *io, size_t size,
                }
 
                page->cp_sync_io = anchor;
+               if (inode && IS_ENCRYPTED(inode)) {
+                       struct page *vmpage = cl_page_vmpage(page);
+
+                       /* In case of Direct IO on encrypted file, we need to
+                        * set the correct page index, and add a reference to
+                        * the mapping. This is required by llcrypt to proceed
+                        * to encryption/decryption, because each block is
+                        * encrypted independently, and each block's IV is set
+                        * to the logical block number within the file.
+                        * This is safe because we know these pages are private
+                        * to the thread doing the Direct IO, and despite
+                        * setting a mapping on the pages, cached lookups will
+                        * not find them.
+                        * Set PageChecked to detect special case of Direct IO
+                        * in osc_brw_fini_request().
+                        * Reference to the mapping and PageChecked flag are
+                        * removed in cl_aio_end().
+                        */
+                       vmpage->index = index++;
+                       vmpage->mapping = inode->i_mapping;
+                       SetPageChecked(vmpage);
+               }
                cl_2queue_add(queue, page);
                /*
                 * Set page clip to tell transfer formation engine
@@ -405,10 +428,6 @@ ll_direct_IO_impl(struct kiocb *iocb, struct iov_iter *iter, int rw)
        loff_t file_offset = iocb->ki_pos;
        struct vvp_io *vio;
 
-       /* if file is encrypted, return 0 so that we fall back to buffered IO */
-       if (IS_ENCRYPTED(inode))
-               return 0;
-
        /* Check EOF by ourselves */
        if (rw == READ && file_offset >= i_size_read(inode))
                return 0;