nfsd: use vfs_fsync for non-directories

Instead of opencoding the fsync calling sequence use vfs_fsync.  This also
gets rid of the useless i_mutex over the data writeout.

Consolidate the remaining special code for syncing directories and document
it's quirks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

1 files changed, 17 insertions, 32 deletions

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index c194793b642b..79d216f276d9 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -769,40 +769,25 @@ nfsd_close(struct file *filp)
 }
 
 /*
- * Sync a file
- * As this calls fsync (not fdatasync) there is no need for a write_inode
- * after it.
+ * Sync a directory to disk.
+ *
+ * We can't just call vfs_fsync because our requirements are slightly odd:
+ *
+ *  a) we do not have a file struct available
+ *  b) we expect to have i_mutex already held by the caller
  */
-static inline int nfsd_dosync(struct file *filp, struct dentry *dp,
-                              const struct file_operations *fop)
-{
-        struct inode *inode = dp->d_inode;
-        int (*fsync) (struct file *, struct dentry *, int);
-        int err;
-
-        err = filemap_write_and_wait(inode->i_mapping);
-        if (err == 0 && fop && (fsync = fop->fsync))
-                err = fsync(filp, dp, 0);
-        return err;
-}
-
-static int
-nfsd_sync(struct file *filp)
+int
+nfsd_sync_dir(struct dentry *dentry)
 {
-        int err;
-        struct inode *inode = filp->f_path.dentry->d_inode;
-        dprintk("nfsd: sync file %s\n", filp->f_path.dentry->d_name.name);
-        mutex_lock(&inode->i_mutex);
-        err=nfsd_dosync(filp, filp->f_path.dentry, filp->f_op);
-        mutex_unlock(&inode->i_mutex);
+        struct inode *inode = dentry->d_inode;
+        int error;
 
-        return err;
-}
+        WARN_ON(!mutex_is_locked(&inode->i_mutex));
 
-int
-nfsd_sync_dir(struct dentry *dp)
-{
-        return nfsd_dosync(NULL, dp, dp->d_inode->i_fop);
+        error = filemap_write_and_wait(inode->i_mapping);
+        if (!error && inode->i_fop->fsync)
+                error = inode->i_fop->fsync(NULL, dentry, 0);
+        return error;
 }
 
 /*
@@ -1008,7 +993,7 @@ static int wait_for_concurrent_writes(struct file *file)
 
         if (inode->i_state & I_DIRTY) {
                 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
-                err = nfsd_sync(file);
+                err = vfs_fsync(file, file->f_path.dentry, 0);
         }
         last_ino = inode->i_ino;
         last_dev = inode->i_sb->s_dev;
@@ -1177,7 +1162,7 @@ nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
                 return err;
         if (EX_ISSYNC(fhp->fh_export)) {
                 if (file->f_op && file->f_op->fsync) {
-                        err = nfserrno(nfsd_sync(file));
+                        err = nfserrno(vfs_fsync(file, file->f_path.dentry, 0));
                 } else {
                         err = nfserr_notsupp;
                 }