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>

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index c194793..79d216f 100644 (file)
--- 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;
                }