nfs4: serialize layoutcommit

Current pnfs_layoutcommit_inode can not handle parallel layoutcommit.
And as Trond suggested , there is no need for client to optimize for
parallel layoutcommit. So add NFS_INO_LAYOUTCOMMITTING flag to
mark inflight layoutcommit and serialize lalyoutcommit with it.
Also mark_inode_dirty_sync if pnfs_layoutcommit_inode fails to issue
layoutcommit.

Reported-by: Vitaliy Gusev <gusev.vitaliy@nexenta.com>
Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index d2ae413c986ac7b38adc3aee5903717c8226c421..b60fddf606f7d23e6f01305420446d74102001a7 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5950,6 +5950,7 @@ static void nfs4_layoutcommit_release(void *calldata)
 {
        struct nfs4_layoutcommit_data *data = calldata;
        struct pnfs_layout_segment *lseg, *tmp;
+       unsigned long *bitlock = &NFS_I(data->args.inode)->flags;
 
        pnfs_cleanup_layoutcommit(data);
        /* Matched by references in pnfs_set_layoutcommit */
@@ -5959,6 +5960,11 @@ static void nfs4_layoutcommit_release(void *calldata)
                                       &lseg->pls_flags))
                        put_lseg(lseg);
        }
+
+       clear_bit_unlock(NFS_INO_LAYOUTCOMMITTING, bitlock);
+       smp_mb__after_clear_bit();
+       wake_up_bit(bitlock, NFS_INO_LAYOUTCOMMITTING);
+
        put_rpccred(data->cred);
        kfree(data);
 }

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index ee73d9a4f70056ea17b33e733cd7ad9ff9713d59..a2478bc74442ae67f8bbc0d5fab936823dcde43e 100644 (file)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1443,17 +1443,31 @@ pnfs_layoutcommit_inode(struct inode *inode, bool sync)
        /* Note kzalloc ensures data->res.seq_res.sr_slot == NULL */
        data = kzalloc(sizeof(*data), GFP_NOFS);
        if (!data) {
-               mark_inode_dirty_sync(inode);
                status = -ENOMEM;
                goto out;
        }
 
+       if (!test_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags))
+               goto out_free;
+
+       if (test_and_set_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags)) {
+               if (!sync) {
+                       status = -EAGAIN;
+                       goto out_free;
+               }
+               status = wait_on_bit_lock(&nfsi->flags, NFS_INO_LAYOUTCOMMITTING,
+                                       nfs_wait_bit_killable, TASK_KILLABLE);
+               if (status)
+                       goto out_free;
+       }
+
        INIT_LIST_HEAD(&data->lseg_list);
        spin_lock(&inode->i_lock);
        if (!test_and_clear_bit(NFS_INO_LAYOUTCOMMIT, &nfsi->flags)) {
+               clear_bit(NFS_INO_LAYOUTCOMMITTING, &nfsi->flags);
                spin_unlock(&inode->i_lock);
-               kfree(data);
-               goto out;
+               wake_up_bit(&nfsi->flags, NFS_INO_LAYOUTCOMMITTING);
+               goto out_free;
        }
 
        pnfs_list_write_lseg(inode, &data->lseg_list);
@@ -1475,6 +1489,11 @@ pnfs_layoutcommit_inode(struct inode *inode, bool sync)
 
        status = nfs4_proc_layoutcommit(data, sync);
 out:
+       if (status)
+               mark_inode_dirty_sync(inode);
        dprintk("<-- %s status %d\n", __func__, status);
        return status;
+out_free:
+       kfree(data);
+       goto out;
 }

diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 60a137b7f17108133aaedb2351da3386457c4a91..ab2c6343361ae3e82f242df7880f292c189e442d 100644 (file)
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -229,6 +229,7 @@ struct nfs_inode {
 #define NFS_INO_COMMIT         (7)             /* inode is committing unstable writes */
 #define NFS_INO_PNFS_COMMIT    (8)             /* use pnfs code for commit */
 #define NFS_INO_LAYOUTCOMMIT   (9)             /* layoutcommit required */
+#define NFS_INO_LAYOUTCOMMITTING (10)          /* layoutcommit inflight */
 
 static inline struct nfs_inode *NFS_I(const struct inode *inode)
 {