From 4c728ef583b3d82266584da5cb068294c09df31e Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Mon, 22 Dec 2008 21:11:15 +0100
Subject: add a vfs_fsync helper
Fsync currently has a fdatawrite/fdatawait pair around the method call,
and a mutex_lock/unlock of the inode mutex. All callers of fsync have
to duplicate this, but we have a few and most of them don't quite get
it right. This patch adds a new vfs_fsync that takes care of this.
It's a little more complicated as usual as ->fsync might get a NULL file
pointer and just a dentry from nfsd, but otherwise gets afile and we
want to take the mapping and file operations from it when it is there.
Notes on the fsync callers:
- ecryptfs wasn't calling filemap_fdatawrite / filemap_fdatawait on the
lower file
- coda wasn't calling filemap_fdatawrite / filemap_fdatawait on the host
file, and returning 0 when ->fsync was missing
- shm wasn't calling either filemap_fdatawrite / filemap_fdatawait nor
taking i_mutex. Now given that shared memory doesn't have disk
backing not doing anything in fsync seems fine and I left it out of
the vfs_fsync conversion for now, but in that case we might just
not pass it through to the lower file at all but just call the no-op
simple_sync_file directly.
[and now actually export vfs_fsync]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
drivers/usb/gadget/file_storage.c | 18 +-----------------
1 file changed, 1 insertion(+), 17 deletions(-)
(limited to 'drivers/usb/gadget/file_storage.c')
diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index c4e62a6297d7..2e71368f45b4 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -1863,26 +1863,10 @@ static int do_write(struct fsg_dev *fsg)
static int fsync_sub(struct lun *curlun)
{
struct file *filp = curlun->filp;
- struct inode *inode;
- int rc, err;
if (curlun->ro || !filp)
return 0;
- if (!filp->f_op->fsync)
- return -EINVAL;
-
- inode = filp->f_path.dentry->d_inode;
- mutex_lock(&inode->i_mutex);
- rc = filemap_fdatawrite(inode->i_mapping);
- err = filp->f_op->fsync(filp, filp->f_path.dentry, 1);
- if (!rc)
- rc = err;
- err = filemap_fdatawait(inode->i_mapping);
- if (!rc)
- rc = err;
- mutex_unlock(&inode->i_mutex);
- VLDBG(curlun, "fdatasync -> %d\n", rc);
- return rc;
+ return vfs_fsync(filp, filp->f_path.dentry, 1);
}
static void fsync_all(struct fsg_dev *fsg)
--
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