[PATCH 39/67] aufs file private data

[hooanon05@yahoo.co.jp]

From: Junjiro Okajima <hooanon05@yahoo.co.jp>

	initial commit
	aufs file private data

Signed-off-by: Junjiro Okajima <hooanon05@yahoo.co.jp>
---
 fs/aufs/finfo.c |  185 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 185 insertions(+), 0 deletions(-)

diff --git a/fs/aufs/finfo.c b/fs/aufs/finfo.c
new file mode 100644
index 0000000..74b2ebf
--- /dev/null
+++ b/fs/aufs/finfo.c
@@ -0,0 +1,185 @@
+/*
+ * Copyright (C) 2005-2008 Junjiro Okajima
+ *
+ * This program, aufs is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+/*
+ * file private data
+ *
+ * $Id: finfo.c,v 1.2 2008/04/21 01:35:14 sfjro Exp $
+ */
+
+#include "aufs.h"
+
+struct au_finfo *au_fi(struct file *file)
+{
+	struct au_finfo *finfo = file->private_data;
+	AuDebugOn(!finfo
+		  || !finfo->fi_hfile
+		  || (0 < finfo->fi_bend
+		      && (/* au_sbi(file->f_dentry->d_sb)->si_bend
+			     < finfo->fi_bend
+			     || */ finfo->fi_bend < finfo->fi_bstart)));
+	return finfo;
+}
+
+struct au_branch *au_fbr(struct file *file, aufs_bindex_t bindex)
+{
+	struct au_finfo *finfo = au_fi(file);
+	struct au_hfile *hf;
+
+	FiMustAnyLock(file);
+	AuDebugOn(!finfo
+		  || finfo->fi_bstart < 0
+		  || bindex < finfo->fi_bstart
+		  || finfo->fi_bend < bindex);
+	hf = finfo->fi_hfile + bindex;
+	AuDebugOn(hf->hf_br && au_br_count(hf->hf_br) <= 0);
+	return hf->hf_br;
+}
+
+struct file *au_h_fptr(struct file *file, aufs_bindex_t bindex)
+{
+	struct au_finfo *finfo = au_fi(file);
+	struct au_hfile *hf;
+
+	FiMustAnyLock(file);
+	AuDebugOn(!finfo
+		  || finfo->fi_bstart < 0
+		  || bindex < finfo->fi_bstart
+		  || finfo->fi_bend < bindex);
+	hf = finfo->fi_hfile + bindex;
+	AuDebugOn(hf->hf_file
+		  && file_count(hf->hf_file) <= 0
+		  && au_br_count(hf->hf_br) <= 0);
+	return hf->hf_file;
+}
+
+void au_hfput(struct au_hfile *hf)
+{
+	if (hf->hf_file->f_mode & FMODE_EXEC)
+		au_allow_write_access(hf->hf_file);
+	fput(hf->hf_file);
+	hf->hf_file = NULL;
+	AuDebugOn(!hf->hf_br);
+	au_br_put(hf->hf_br);
+	hf->hf_br = NULL;
+}
+
+void au_set_h_fptr(struct file *file, aufs_bindex_t bindex, struct file *val)
+{
+	struct au_finfo *finfo = au_fi(file);
+	struct au_hfile *hf;
+
+	FiMustWriteLock(file);
+	AuDebugOn(!finfo
+		  || finfo->fi_bstart < 0
+		  || bindex < finfo->fi_bstart
+		  || finfo->fi_bend < bindex);
+	AuDebugOn(val && file_count(val) <= 0);
+	hf = finfo->fi_hfile + bindex;
+	AuDebugOn(val && hf->hf_file);
+	if (hf->hf_file)
+		au_hfput(hf);
+	if (val) {
+		hf->hf_file = val;
+		hf->hf_br = au_sbr(file->f_dentry->d_sb, bindex);
+	}
+}
+
+void au_finfo_fin(struct file *file)
+{
+	struct au_finfo *finfo;
+	struct dentry *dentry;
+	aufs_bindex_t bindex, bend;
+
+	dentry = file->f_dentry;
+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
+	SiMustAnyLock(dentry->d_sb);
+
+	fi_write_lock(file);
+	bend = au_fbend(file);
+	bindex = au_fbstart(file);
+	if (bindex >= 0)
+		for (; bindex <= bend; bindex++)
+			au_set_h_fptr(file, bindex, NULL);
+
+	finfo = au_fi(file);
+#ifdef CONFIG_AUFS_DEBUG
+	if (finfo->fi_bstart >= 0) {
+		bend = au_fbend(file);
+		for (bindex = finfo->fi_bstart; bindex <= bend; bindex++) {
+			struct au_hfile *hf;
+			hf = finfo->fi_hfile + bindex;
+			AuDebugOn(hf->hf_file || hf->hf_br);
+		}
+	}
+#endif
+
+	kfree(finfo->fi_hfile);
+	fi_write_unlock(file);
+	au_cache_free_finfo(finfo);
+	//file->private_data = NULL;
+}
+
+int au_finfo_init(struct file *file)
+{
+	struct au_finfo *finfo;
+	struct dentry *dentry;
+	union {
+		void *p;
+		unsigned long ul;
+	} u;
+
+	dentry = file->f_dentry;
+	LKTRTrace("%.*s\n", AuDLNPair(dentry));
+	AuDebugOn(!dentry->d_inode);
+
+	finfo = au_cache_alloc_finfo();
+	if (finfo) {
+		finfo->fi_hfile = kcalloc(au_sbend(dentry->d_sb) + 1,
+					  sizeof(*finfo->fi_hfile), GFP_KERNEL);
+		if (finfo->fi_hfile) {
+			au_rw_init_wlock(&finfo->fi_rwsem);
+			finfo->fi_bstart = -1;
+			finfo->fi_bend = -1;
+			atomic_set(&finfo->fi_generation, au_digen(dentry));
+			//smp_mb(); /* atomic_set */
+
+			/*
+			 * a dirty trick for handling FMODE_EXEC and
+			 * deny_write_access().
+			 * because FMODE_EXEC flag is not passed to
+			 * f_op->open(),
+			 * aufs set it to file->private_data temporary in lookup
+			 * or dentry revalidation operations.
+			 * restore the flag to f_mode here.
+			 */
+			u.p = file->private_data;
+			if (u.ul & FMODE_EXEC) {
+				file->f_mode |= FMODE_EXEC;
+				smp_mb(); /* flush f_mode */
+			}
+
+			file->private_data = finfo;
+			return 0; /* success */
+		}
+		au_cache_free_finfo(finfo);
+	}
+
+	AuTraceErr(-ENOMEM);
+	return -ENOMEM;
+}
-- 
1.4.4.4