Merge branch 'nfsd-next' of git://linux-nfs.org/~bfields/linux

[~andy/linux] / fs / xfs / xfs_log_cil.c

diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index cdebd832c3dba1fcd937869d1cedcebe09113c25..4ef6fdbced78b7e99680f9e4e8afbb502a7bce92 100644 (file)
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -205,16 +205,25 @@ xlog_cil_insert_format_items(
                /*
                 * We 64-bit align the length of each iovec so that the start
                 * of the next one is naturally aligned.  We'll need to
-                * account for that slack space here.
+                * account for that slack space here. Then round nbytes up
+                * to 64-bit alignment so that the initial buffer alignment is
+                * easy to calculate and verify.
                 */
                nbytes += niovecs * sizeof(uint64_t);
+               nbytes = round_up(nbytes, sizeof(uint64_t));
 
                /* grab the old item if it exists for reservation accounting */
                old_lv = lip->li_lv;
 
-               /* calc buffer size */
-               buf_size = sizeof(struct xfs_log_vec) + nbytes +
-                               niovecs * sizeof(struct xfs_log_iovec);
+               /*
+                * The data buffer needs to start 64-bit aligned, so round up
+                * that space to ensure we can align it appropriately and not
+                * overrun the buffer.
+                */
+               buf_size = nbytes +
+                          round_up((sizeof(struct xfs_log_vec) +
+                                    niovecs * sizeof(struct xfs_log_iovec)),
+                                   sizeof(uint64_t));
 
                /* compare to existing item size */
                if (lip->li_lv && buf_size <= lip->li_lv->lv_size) {
@@ -251,6 +260,8 @@ xlog_cil_insert_format_items(
                /* The allocated data region lies beyond the iovec region */
                lv->lv_buf_len = 0;
                lv->lv_buf = (char *)lv + buf_size - nbytes;
+               ASSERT(IS_ALIGNED((unsigned long)lv->lv_buf, sizeof(uint64_t)));
+
                lip->li_ops->iop_format(lip, lv);
 insert:
                ASSERT(lv->lv_buf_len <= nbytes);