NFS/pNFS: Fix up pNFS write reschedule layering violations and bugs

The flexfiles layout in particular, seems to want to poke around in the
O_DIRECT flags when retransmitting.
This patch sets up an interface to allow it to call back into O_DIRECT
to handle retransmission correctly. It also fixes a potential bug whereby
we could change the behaviour of O_DIRECT if an error is already pending.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 4b1d08f56aba7940bf0872265902b2c793b05607..e73693f75dee638af922b74d837e9058337f3191 100644 (file)
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -117,12 +117,6 @@ static inline int put_dreq(struct nfs_direct_req *dreq)
        return atomic_dec_and_test(&dreq->io_count);
 }
 
-void nfs_direct_set_resched_writes(struct nfs_direct_req *dreq)
-{
-       dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
-}
-EXPORT_SYMBOL_GPL(nfs_direct_set_resched_writes);
-
 static void
 nfs_direct_good_bytes(struct nfs_direct_req *dreq, struct nfs_pgio_header *hdr)
 {
@@ -839,10 +833,25 @@ static void nfs_write_sync_pgio_error(struct list_head *head)
        }
 }
 
+static void nfs_direct_write_reschedule_io(struct nfs_pgio_header *hdr)
+{
+       struct nfs_direct_req *dreq = hdr->dreq;
+
+       spin_lock(&dreq->lock);
+       if (dreq->error == 0) {
+               dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
+               /* fake unstable write to let common nfs resend pages */
+               hdr->verf.committed = NFS_UNSTABLE;
+               hdr->good_bytes = hdr->args.count;
+       }
+       spin_unlock(&dreq->lock);
+}
+
 static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = {
        .error_cleanup = nfs_write_sync_pgio_error,
        .init_hdr = nfs_direct_pgio_init,
        .completion = nfs_direct_write_completion,
+       .reschedule_io = nfs_direct_write_reschedule_io,
 };
 
 

diff --git a/fs/nfs/flexfilelayout/flexfilelayout.c b/fs/nfs/flexfilelayout/flexfilelayout.c
index 03516c80855a02b7513370e8f5b21d420f3327d7..df475d42df7765852b245378c400b5de5db710f8 100644 (file)
--- a/fs/nfs/flexfilelayout/flexfilelayout.c
+++ b/fs/nfs/flexfilelayout/flexfilelayout.c
@@ -912,18 +912,7 @@ static void ff_layout_reset_write(struct nfs_pgio_header *hdr, bool retry_pnfs)
                        hdr->args.count,
                        (unsigned long long)hdr->args.offset);
 
-               if (!hdr->dreq) {
-                       struct nfs_open_context *ctx;
-
-                       ctx = nfs_list_entry(hdr->pages.next)->wb_context;
-                       set_bit(NFS_CONTEXT_RESEND_WRITES, &ctx->flags);
-                       hdr->completion_ops->error_cleanup(&hdr->pages);
-               } else {
-                       nfs_direct_set_resched_writes(hdr->dreq);
-                       /* fake unstable write to let common nfs resend pages */
-                       hdr->verf.committed = NFS_UNSTABLE;
-                       hdr->good_bytes = hdr->args.count;
-               }
+               hdr->completion_ops->reschedule_io(hdr);
                return;
        }
 

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 313d55402238fd2f0328ef94d57e13cfd0da3e7c..99a2919047e9b0e6ccad3d8867836db7cf3a2a4c 100644 (file)
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -519,7 +519,6 @@ static inline void nfs_inode_dio_wait(struct inode *inode)
        inode_dio_wait(inode);
 }
 extern ssize_t nfs_dreq_bytes_left(struct nfs_direct_req *dreq);
-extern void nfs_direct_set_resched_writes(struct nfs_direct_req *dreq);
 
 /* nfs4proc.c */
 extern void __nfs4_read_done_cb(struct nfs_pgio_header *);

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 7b93164069307346ea43f130e3883959ae6576b6..0aa3e6b3db70ad1e7eb35efac0c391b106f7fbb7 100644 (file)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1326,9 +1326,15 @@ static void nfs_async_write_error(struct list_head *head)
        }
 }
 
+static void nfs_async_write_reschedule_io(struct nfs_pgio_header *hdr)
+{
+       nfs_async_write_error(&hdr->pages);
+}
+
 static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = {
        .error_cleanup = nfs_async_write_error,
        .completion = nfs_write_completion,
+       .reschedule_io = nfs_async_write_reschedule_io,
 };
 
 void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio,

diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 11bbae44f4cbf91dd3ed62aa9d2e1849b14a8839..e89dbb14138c260f1a130ed20d25195469dfeca4 100644 (file)
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1460,6 +1460,7 @@ struct nfs_pgio_completion_ops {
        void    (*error_cleanup)(struct list_head *head);
        void    (*init_hdr)(struct nfs_pgio_header *hdr);
        void    (*completion)(struct nfs_pgio_header *hdr);
+       void    (*reschedule_io)(struct nfs_pgio_header *hdr);
 };
 
 struct nfs_unlinkdata {