NFS: Replace __nfs_write_mapping with sync_inode()

Now that we have correct COMMIT semantics in writeback_single_inode, we can
reduce and simplify nfs_wb_all(). Also replace nfs_wb_nocommit() with a
call to filemap_write_and_wait(), which doesn't need to hold the
inode->i_mutex.

With that done, we can eliminate nfs_write_mapping() altogether.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index aa5a831..443772d 100644 (file)
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -495,17 +495,11 @@ int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
        int need_atime = NFS_I(inode)->cache_validity & NFS_INO_INVALID_ATIME;
        int err;
 
-       /*
-        * Flush out writes to the server in order to update c/mtime.
-        *
-        * Hold the i_mutex to suspend application writes temporarily;
-        * this prevents long-running writing applications from blocking
-        * nfs_wb_nocommit.
-        */
+       /* Flush out writes to the server in order to update c/mtime.  */
        if (S_ISREG(inode->i_mode)) {
-               mutex_lock(&inode->i_mutex);
-               nfs_wb_nocommit(inode);
-               mutex_unlock(&inode->i_mutex);
+               err = filemap_write_and_wait(inode->i_mapping);
+               if (err)
+                       goto out;
        }
 
        /*
@@ -529,6 +523,7 @@ int nfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
                generic_fillattr(inode, stat);
                stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
        }
+out:
        return err;
 }
 

diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index dc7f5e9..0b32309 100644 (file)
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1454,7 +1454,6 @@ long nfs_sync_mapping_wait(struct address_space *mapping, struct writeback_contr
        pgoff_t idx_start, idx_end;
        unsigned int npages = 0;
        LIST_HEAD(head);
-       int nocommit = how & FLUSH_NOCOMMIT;
        long pages, ret;
 
        /* FIXME */
@@ -1471,14 +1470,11 @@ long nfs_sync_mapping_wait(struct address_space *mapping, struct writeback_contr
                                npages = 0;
                }
        }
-       how &= ~FLUSH_NOCOMMIT;
        spin_lock(&inode->i_lock);
        do {
                ret = nfs_wait_on_requests_locked(inode, idx_start, npages);
                if (ret != 0)
                        continue;
-               if (nocommit)
-                       break;
                pages = nfs_scan_commit(inode, &head, idx_start, npages);
                if (pages == 0)
                        break;
@@ -1492,47 +1488,19 @@ long nfs_sync_mapping_wait(struct address_space *mapping, struct writeback_contr
        return ret;
 }
 
-static int __nfs_write_mapping(struct address_space *mapping, struct writeback_control *wbc, int how)
-{
-       int ret;
-
-       ret = nfs_writepages(mapping, wbc);
-       if (ret < 0)
-               goto out;
-       ret = nfs_sync_mapping_wait(mapping, wbc, how);
-       if (ret < 0)
-               goto out;
-       return 0;
-out:
-       __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
-       return ret;
-}
-
-/* Two pass sync: first using WB_SYNC_NONE, then WB_SYNC_ALL */
-static int nfs_write_mapping(struct address_space *mapping, int how)
+/*
+ * flush the inode to disk.
+ */
+int nfs_wb_all(struct inode *inode)
 {
        struct writeback_control wbc = {
-               .bdi = mapping->backing_dev_info,
                .sync_mode = WB_SYNC_ALL,
                .nr_to_write = LONG_MAX,
                .range_start = 0,
                .range_end = LLONG_MAX,
        };
 
-       return __nfs_write_mapping(mapping, &wbc, how);
-}
-
-/*
- * flush the inode to disk.
- */
-int nfs_wb_all(struct inode *inode)
-{
-       return nfs_write_mapping(inode->i_mapping, 0);
-}
-
-int nfs_wb_nocommit(struct inode *inode)
-{
-       return nfs_write_mapping(inode->i_mapping, FLUSH_NOCOMMIT);
+       return sync_inode(inode, &wbc);
 }
 
 int nfs_wb_page_cancel(struct inode *inode, struct page *page)

diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 1083134..93f439e 100644 (file)
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -33,7 +33,6 @@
 #define FLUSH_STABLE           4       /* commit to stable storage */
 #define FLUSH_LOWPRI           8       /* low priority background flush */
 #define FLUSH_HIGHPRI          16      /* high priority memory reclaim flush */
-#define FLUSH_NOCOMMIT         32      /* Don't send the NFSv3/v4 COMMIT */
 
 #ifdef __KERNEL__
 
@@ -478,7 +477,6 @@ extern int nfs_writeback_done(struct rpc_task *, struct nfs_write_data *);
  */
 extern long nfs_sync_mapping_wait(struct address_space *, struct writeback_control *, int);
 extern int nfs_wb_all(struct inode *inode);
-extern int nfs_wb_nocommit(struct inode *inode);
 extern int nfs_wb_page(struct inode *inode, struct page* page);
 extern int nfs_wb_page_cancel(struct inode *inode, struct page* page);
 #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)