[Cluster-devel] [PATCH 25/29] xfs: support nowait for xfs_buf_item_init()

[Hao Xu]

From: Hao Xu <howe...@tencent.com>

support nowait for xfs_buf_item_init() and error out -EAGAIN to
_xfs_trans_bjoin() when it would block.

Signed-off-by: Hao Xu <howe...@tencent.com>
---
 fs/xfs/xfs_buf_item.c         |  9 +++++++--
 fs/xfs/xfs_buf_item.h         |  2 +-
 fs/xfs/xfs_buf_item_recover.c |  2 +-
 fs/xfs/xfs_trans_buf.c        | 16 +++++++++++++---
 4 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 023d4e0385dd..b1e63137d65b 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -827,7 +827,8 @@ xfs_buf_item_free_format(
 int
 xfs_buf_item_init(
        struct xfs_buf  *bp,
-       struct xfs_mount *mp)
+       struct xfs_mount *mp,
+       bool   nowait)
 {
        struct xfs_buf_log_item *bip = bp->b_log_item;
        int                     chunks;
@@ -847,7 +848,11 @@ xfs_buf_item_init(
                return 0;
        }
 
-       bip = kmem_cache_zalloc(xfs_buf_item_cache, GFP_KERNEL | __GFP_NOFAIL);
+       bip = kmem_cache_zalloc(xfs_buf_item_cache,
+                               GFP_KERNEL | (nowait ? 0 : __GFP_NOFAIL));
+       if (!bip)
+               return -EAGAIN;
+
        xfs_log_item_init(mp, &bip->bli_item, XFS_LI_BUF, &xfs_buf_item_ops);
        bip->bli_buf = bp;
 
diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h
index 4d8a6aece995..b1daf8988280 100644
--- a/fs/xfs/xfs_buf_item.h
+++ b/fs/xfs/xfs_buf_item.h
@@ -47,7 +47,7 @@ struct xfs_buf_log_item {
        struct xfs_buf_log_format __bli_format; /* embedded in-log header */
 };
 
-int    xfs_buf_item_init(struct xfs_buf *, struct xfs_mount *);
+int    xfs_buf_item_init(struct xfs_buf *bp, struct xfs_mount *mp, bool 
nowait);
 void   xfs_buf_item_done(struct xfs_buf *bp);
 void   xfs_buf_item_relse(struct xfs_buf *);
 bool   xfs_buf_item_put(struct xfs_buf_log_item *);
diff --git a/fs/xfs/xfs_buf_item_recover.c b/fs/xfs/xfs_buf_item_recover.c
index 43167f543afc..aa64d5a499d6 100644
--- a/fs/xfs/xfs_buf_item_recover.c
+++ b/fs/xfs/xfs_buf_item_recover.c
@@ -429,7 +429,7 @@ xlog_recover_validate_buf_type(
                struct xfs_buf_log_item *bip;
 
                bp->b_flags |= _XBF_LOGRECOVERY;
-               xfs_buf_item_init(bp, mp);
+               xfs_buf_item_init(bp, mp, false);
                bip = bp->b_log_item;
                bip->bli_item.li_lsn = current_lsn;
        }
diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
index 016371f58f26..a1e4f2e8629a 100644
--- a/fs/xfs/xfs_trans_buf.c
+++ b/fs/xfs/xfs_trans_buf.c
@@ -57,13 +57,14 @@ xfs_trans_buf_item_match(
  * If the buffer does not yet have a buf log item associated with it,
  * then allocate one for it.  Then add the buf item to the transaction.
  */
-STATIC void
+STATIC int
 _xfs_trans_bjoin(
        struct xfs_trans        *tp,
        struct xfs_buf          *bp,
        int                     reset_recur)
 {
        struct xfs_buf_log_item *bip;
+       int ret;
 
        ASSERT(bp->b_transp == NULL);
 
@@ -72,7 +73,11 @@ _xfs_trans_bjoin(
         * it doesn't have one yet, then allocate one and initialize it.
         * The checks to see if one is there are in xfs_buf_item_init().
         */
-       xfs_buf_item_init(bp, tp->t_mountp);
+       ret = xfs_buf_item_init(bp, tp->t_mountp,
+                               tp->t_flags & XFS_TRANS_NOWAIT);
+       if (ret < 0)
+               return ret;
+
        bip = bp->b_log_item;
        ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
        ASSERT(!(bip->__bli_format.blf_flags & XFS_BLF_CANCEL));
@@ -92,6 +97,7 @@ _xfs_trans_bjoin(
        xfs_trans_add_item(tp, &bip->bli_item);
        bp->b_transp = tp;
 
+       return 0;
 }
 
 void
@@ -309,7 +315,11 @@ xfs_trans_read_buf_map(
        }
 
        if (tp) {
-               _xfs_trans_bjoin(tp, bp, 1);
+               error = _xfs_trans_bjoin(tp, bp, 1);
+               if (error) {
+                       xfs_buf_relse(bp);
+                       return error;
+               }
                trace_xfs_trans_read_buf(bp->b_log_item);
        }
        ASSERT(bp->b_ops != NULL || ops == NULL);
-- 
2.25.1