1 files changed, 51 insertions, 24 deletions

diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index d0833b54e55d..02b9cf3f8252 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -127,6 +127,7 @@ xlog_cil_prepare_log_vecs(
                 int     index;
                 int     len = 0;
                 uint    niovecs;
+                bool    ordered = false;
 
                 /* Skip items which aren't dirty in this transaction. */
                 if (!(lidp->lid_flags & XFS_LID_DIRTY))
@@ -137,14 +138,30 @@ xlog_cil_prepare_log_vecs(
                 if (!niovecs)
                         continue;
 
+                /*
+                 * Ordered items need to be tracked but we do not wish to write
+                 * them. We need a logvec to track the object, but we do not
+                 * need an iovec or buffer to be allocated for copying data.
+                 */
+                if (niovecs == XFS_LOG_VEC_ORDERED) {
+                        ordered = true;
+                        niovecs = 0;
+                }
+
                 new_lv = kmem_zalloc(sizeof(*new_lv) +
                                 niovecs * sizeof(struct xfs_log_iovec),
                                 KM_SLEEP|KM_NOFS);
 
+                new_lv->lv_item = lidp->lid_item;
+                new_lv->lv_niovecs = niovecs;
+                if (ordered) {
+                        /* track as an ordered logvec */
+                        new_lv->lv_buf_len = XFS_LOG_VEC_ORDERED;
+                        goto next;
+                }
+
                 /* The allocated iovec region lies beyond the log vector. */
                 new_lv->lv_iovecp = (struct xfs_log_iovec *)&new_lv[1];
-                new_lv->lv_niovecs = niovecs;
-                new_lv->lv_item = lidp->lid_item;
 
                 /* build the vector array and calculate it's length */
                 IOP_FORMAT(new_lv->lv_item, new_lv->lv_iovecp);
@@ -165,6 +182,7 @@ xlog_cil_prepare_log_vecs(
                 }
                 ASSERT(ptr == new_lv->lv_buf + new_lv->lv_buf_len);
 
+next:
                 if (!ret_lv)
                         ret_lv = new_lv;
                 else
@@ -191,8 +209,18 @@ xfs_cil_prepare_item(
 
         if (old) {
                 /* existing lv on log item, space used is a delta */
-                ASSERT(!list_empty(&lv->lv_item->li_cil));
-                ASSERT(old->lv_buf && old->lv_buf_len && old->lv_niovecs);
+                ASSERT((old->lv_buf && old->lv_buf_len && old->lv_niovecs) ||
+                        old->lv_buf_len == XFS_LOG_VEC_ORDERED);
+
+                /*
+                 * If the new item is ordered, keep the old one that is already
+                 * tracking dirty or ordered regions
+                 */
+                if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED) {
+                        ASSERT(!lv->lv_buf);
+                        kmem_free(lv);
+                        return;
+                }
 
                 *len += lv->lv_buf_len - old->lv_buf_len;
                 *diff_iovecs += lv->lv_niovecs - old->lv_niovecs;
@@ -201,10 +229,11 @@ xfs_cil_prepare_item(
         } else {
                 /* new lv, must pin the log item */
                 ASSERT(!lv->lv_item->li_lv);
-                ASSERT(list_empty(&lv->lv_item->li_cil));
 
-                *len += lv->lv_buf_len;
-                *diff_iovecs += lv->lv_niovecs;
+                if (lv->lv_buf_len != XFS_LOG_VEC_ORDERED) {
+                        *len += lv->lv_buf_len;
+                        *diff_iovecs += lv->lv_niovecs;
+                }
                 IOP_PIN(lv->lv_item);
 
         }
@@ -259,18 +288,24 @@ xlog_cil_insert_items(
          * We can do this safely because the context can't checkpoint until we
          * are done so it doesn't matter exactly how we update the CIL.
          */
-        for (lv = log_vector; lv; lv = lv->lv_next)
-                xfs_cil_prepare_item(log, lv, &len, &diff_iovecs);
-
-        /* account for space used by new iovec headers  */
-        len += diff_iovecs * sizeof(xlog_op_header_t);
-
         spin_lock(&cil->xc_cil_lock);
+        for (lv = log_vector; lv; ) {
+                struct xfs_log_vec *next = lv->lv_next;
 
-        /* move the items to the tail of the CIL */
-        for (lv = log_vector; lv; lv = lv->lv_next)
+                ASSERT(lv->lv_item->li_lv || list_empty(&lv->lv_item->li_cil));
+                lv->lv_next = NULL;
+
+                /*
+                 * xfs_cil_prepare_item() may free the lv, so move the item on
+                 * the CIL first.
+                 */
                 list_move_tail(&lv->lv_item->li_cil, &cil->xc_cil);
+                xfs_cil_prepare_item(log, lv, &len, &diff_iovecs);
+                lv = next;
+        }
 
+        /* account for space used by new iovec headers  */
+        len += diff_iovecs * sizeof(xlog_op_header_t);
         ctx->nvecs += diff_iovecs;
 
         /*
@@ -381,9 +416,7 @@ xlog_cil_push(
         struct xfs_cil_ctx      *new_ctx;
         struct xlog_in_core     *commit_iclog;
         struct xlog_ticket      *tic;
-        int                     num_lv;
         int                     num_iovecs;
-        int                     len;
         int                     error = 0;
         struct xfs_trans_header thdr;
         struct xfs_log_iovec    lhdr;
@@ -428,12 +461,9 @@ xlog_cil_push(
          * side which is currently locked out by the flush lock.
          */
         lv = NULL;
-        num_lv = 0;
         num_iovecs = 0;
-        len = 0;
         while (!list_empty(&cil->xc_cil)) {
                 struct xfs_log_item     *item;
-                int                     i;
 
                 item = list_first_entry(&cil->xc_cil,
                                         struct xfs_log_item, li_cil);
@@ -444,11 +474,7 @@ xlog_cil_push(
                         lv->lv_next = item->li_lv;
                 lv = item->li_lv;
                 item->li_lv = NULL;
-
-                num_lv++;
                 num_iovecs += lv->lv_niovecs;
-                for (i = 0; i < lv->lv_niovecs; i++)
-                        len += lv->lv_iovecp[i].i_len;
         }
 
         /*
@@ -701,6 +727,7 @@ xfs_log_commit_cil(
         if (commit_lsn)
                 *commit_lsn = log->l_cilp->xc_ctx->sequence;
 
+        /* xlog_cil_insert_items() destroys log_vector list */
         xlog_cil_insert_items(log, log_vector, tp->t_ticket);
 
         /* check we didn't blow the reservation */