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Commit 9a8d248e authored by J. Bruce Fields's avatar J. Bruce Fields
Browse files

nfsd: fix double-locks of directory mutex 



A number of nfsd operations depend on the i_mutex to cover more code
than just the fsync, so the approach of 4c728ef5 "add a vfs_fsync
helper" doesn't work for nfsd.  Revert the parts of those patches that
touch nfsd.

Note: we can't, however, remove the logic from vfs_fsync that was needed
only for the special case of nfsd, because a vfs_fsync(NULL,...) call
can still result indirectly from a stackable filesystem that was called
by nfsd.  (Thanks to Christoph Hellwig for pointing this out.)

Reported-by: default avatarEric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent 2779e3ae

fs/nfsd/vfs.c

+31 −3
Original line number Diff line number Diff line
@@ -744,16 +744,44 @@ nfsd_close(struct file *filp) 
	fput(filp);

}



/*

 * Sync a file

 * As this calls fsync (not fdatasync) there is no need for a write_inode

 * after it.

 */

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_fdatawrite(inode->i_mapping);

	if (err == 0 && fop && (fsync = fop->fsync))

		err = fsync(filp, dp, 0);

	if (err == 0)

		err = filemap_fdatawait(inode->i_mapping);



	return err;

}



static int

nfsd_sync(struct file *filp)

{

	return vfs_fsync(filp, filp->f_path.dentry, 0);

        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);



	return err;

}



int

nfsd_sync_dir(struct dentry *dentry)

nfsd_sync_dir(struct dentry *dp)

{

	return vfs_fsync(NULL, dentry, 0);

	return nfsd_dosync(NULL, dp, dp->d_inode->i_fop);

}



/*