xfs: automatic dfops buffer relogging

Source kernel commit: 82ff27bc52a88cb5cc400bfa64e210d3ec8dfebd

Buffers that are held across deferred operations are explicitly
joined to the dfops structure to ensure appropriate relogging.
While buffers are currently joined explicitly, we can detect the
conditions that require relogging at dfops finish time by inspecting
the transaction item list for held buffers.

Replace the xfs_defer_bjoin() infrastructure with such detection and
automatic relogging of held buffers. This eliminates the need for
the per-dfops buffer list, replaced by an on-stack variant in
xfs_defer_trans_roll().

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>

diff --git a/include/xfs_trans.h b/include/xfs_trans.h
index c35f1f4187b2a292dec3d9b7fada1a42394d456b..a967a7ffb9705441ef2ee5cec3bfa87812bba812 100644 (file)
--- a/include/xfs_trans.h
+++ b/include/xfs_trans.h
@@ -69,7 +69,6 @@ struct xfs_defer_ops {
 
        /* relog these with each roll */
        struct xfs_inode                *dop_inodes[XFS_DEFER_OPS_NR_INODES];
-       struct xfs_buf          *dop_bufs[XFS_DEFER_OPS_NR_BUFS];
 };
 
 typedef struct xfs_trans {

diff --git a/libxfs/xfs_attr.c b/libxfs/xfs_attr.c
index 63c92c76455c9eb1af34b480cdb268c7c279c8cb..b63f385e5f1f60a580974e6c9a443bfb85a7bdc8 100644 (file)
--- a/libxfs/xfs_attr.c
+++ b/libxfs/xfs_attr.c
@@ -315,7 +315,6 @@ xfs_attr_set(
                 * buffer and run into problems with the write verifier.
                 */
                xfs_trans_bhold(args.trans, leaf_bp);
-               xfs_defer_bjoin(args.trans->t_dfops, leaf_bp);
                xfs_defer_ijoin(args.trans->t_dfops, dp);
                error = xfs_defer_finish(&args.trans);
                if (error)

diff --git a/libxfs/xfs_defer.c b/libxfs/xfs_defer.c
index b7e4319c170bb808372aad654b9ca814d0dbf5eb..942bfa93070de734f60238759e45752a3ba804d5 100644 (file)
--- a/libxfs/xfs_defer.c
+++ b/libxfs/xfs_defer.c
@@ -228,6 +228,10 @@ xfs_defer_trans_roll(
        struct xfs_trans                **tp)
 {
        struct xfs_defer_ops            *dop = (*tp)->t_dfops;
+       struct xfs_buf_log_item         *bli;
+       struct xfs_log_item             *lip;
+       struct xfs_buf                  *bplist[XFS_DEFER_OPS_NR_BUFS];
+       int                             bpcount = 0;
        int                             i;
        int                             error;
 
@@ -235,9 +239,24 @@ xfs_defer_trans_roll(
        for (i = 0; i < XFS_DEFER_OPS_NR_INODES && dop->dop_inodes[i]; i++)
                xfs_trans_log_inode(*tp, dop->dop_inodes[i], XFS_ILOG_CORE);
 
-       /* Hold the (previously bjoin'd) buffer locked across the roll. */
-       for (i = 0; i < XFS_DEFER_OPS_NR_BUFS && dop->dop_bufs[i]; i++)
-               xfs_trans_dirty_buf(*tp, dop->dop_bufs[i]);
+       list_for_each_entry(lip, &(*tp)->t_items, li_trans) {
+               switch (lip->li_type) {
+               case XFS_LI_BUF:
+                       bli = container_of(lip, struct xfs_buf_log_item,
+                                          bli_item);
+                       if (bli->bli_flags & XFS_BLI_HOLD) {
+                               if (bpcount >= XFS_DEFER_OPS_NR_BUFS) {
+                                       ASSERT(0);
+                                       return -EFSCORRUPTED;
+                               }
+                               xfs_trans_dirty_buf(*tp, bli->bli_buf);
+                               bplist[bpcount++] = bli->bli_buf;
+                       }
+                       break;
+               default:
+                       break;
+               }
+       }
 
        trace_xfs_defer_trans_roll((*tp)->t_mountp, dop, _RET_IP_);
 
@@ -255,9 +274,9 @@ xfs_defer_trans_roll(
                xfs_trans_ijoin(*tp, dop->dop_inodes[i], 0);
 
        /* Rejoin the buffers and dirty them so the log moves forward. */
-       for (i = 0; i < XFS_DEFER_OPS_NR_BUFS && dop->dop_bufs[i]; i++) {
-               xfs_trans_bjoin(*tp, dop->dop_bufs[i]);
-               xfs_trans_bhold(*tp, dop->dop_bufs[i]);
+       for (i = 0; i < bpcount; i++) {
+               xfs_trans_bjoin(*tp, bplist[i]);
+               xfs_trans_bhold(*tp, bplist[i]);
        }
 
        return error;
@@ -295,30 +314,6 @@ xfs_defer_ijoin(
        return -EFSCORRUPTED;
 }
 
-/*
- * Add this buffer to the deferred op.  Each joined buffer is relogged
- * each time we roll the transaction.
- */
-int
-xfs_defer_bjoin(
-       struct xfs_defer_ops            *dop,
-       struct xfs_buf                  *bp)
-{
-       int                             i;
-
-       for (i = 0; i < XFS_DEFER_OPS_NR_BUFS; i++) {
-               if (dop->dop_bufs[i] == bp)
-                       return 0;
-               else if (dop->dop_bufs[i] == NULL) {
-                       dop->dop_bufs[i] = bp;
-                       return 0;
-               }
-       }
-
-       ASSERT(0);
-       return -EFSCORRUPTED;
-}
-
 /*
  * Reset an already used dfops after finish.
  */
@@ -331,7 +326,6 @@ xfs_defer_reset(
        ASSERT(!xfs_defer_has_unfinished_work(dop));
 
        memset(dop->dop_inodes, 0, sizeof(dop->dop_inodes));
-       memset(dop->dop_bufs, 0, sizeof(dop->dop_bufs));
 
        /*
         * Low mode state transfers across transaction rolls to mirror dfops
@@ -594,7 +588,6 @@ xfs_defer_move(
        list_splice_init(&src->dop_pending, &dst->dop_pending);
 
        memcpy(dst->dop_inodes, src->dop_inodes, sizeof(dst->dop_inodes));
-       memcpy(dst->dop_bufs, src->dop_bufs, sizeof(dst->dop_bufs));
 
        /*
         * Low free space mode was historically controlled by a dfops field.

diff --git a/libxfs/xfs_defer.h b/libxfs/xfs_defer.h
index 8908a2716774a9c01cd702f216b3cf92962c2030..4a8bb838adf233b4c2c5979b5831a12369b0a31c 100644 (file)
--- a/libxfs/xfs_defer.h
+++ b/libxfs/xfs_defer.h
@@ -43,7 +43,6 @@ void xfs_defer_cancel(struct xfs_trans *);
 void xfs_defer_init(struct xfs_trans *tp, struct xfs_defer_ops *dop);
 bool xfs_defer_has_unfinished_work(struct xfs_defer_ops *dop);
 int xfs_defer_ijoin(struct xfs_defer_ops *dop, struct xfs_inode *ip);
-int xfs_defer_bjoin(struct xfs_defer_ops *dop, struct xfs_buf *bp);
 void xfs_defer_move(struct xfs_trans *dtp, struct xfs_trans *stp);
 
 /* Description of a deferred type. */