Linux-libre 4.2.1-gnupck-4.2.1-gnu

1 files changed, 157 insertions, 0 deletions

diff --git a/fs/aufs/sysrq.c b/fs/aufs/sysrq.c
new file mode 100644
index 000000000..a3e95bce6
--- /dev/null
+++ b/fs/aufs/sysrq.c
@@ -0,0 +1,157 @@
+/*
+ * Copyright (C) 2005-2015 Junjiro R. 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, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * magic sysrq hanlder
+ */
+
+/* #include <linux/sysrq.h> */
+#include <linux/writeback.h>
+#include "aufs.h"
+
+/* ---------------------------------------------------------------------- */
+
+static void sysrq_sb(struct super_block *sb)
+{
+	char *plevel;
+	struct au_sbinfo *sbinfo;
+	struct file *file;
+	struct au_sphlhead *files;
+	struct au_finfo *finfo;
+
+	plevel = au_plevel;
+	au_plevel = KERN_WARNING;
+
+	/* since we define pr_fmt, call printk directly */
+#define pr(str) printk(KERN_WARNING AUFS_NAME ": " str)
+
+	sbinfo = au_sbi(sb);
+	printk(KERN_WARNING "si=%lx\n", sysaufs_si_id(sbinfo));
+	pr("superblock\n");
+	au_dpri_sb(sb);
+
+#if 0
+	pr("root dentry\n");
+	au_dpri_dentry(sb->s_root);
+	pr("root inode\n");
+	au_dpri_inode(d_inode(sb->s_root));
+#endif
+
+#if 0
+	do {
+		int err, i, j, ndentry;
+		struct au_dcsub_pages dpages;
+		struct au_dpage *dpage;
+
+		err = au_dpages_init(&dpages, GFP_ATOMIC);
+		if (unlikely(err))
+			break;
+		err = au_dcsub_pages(&dpages, sb->s_root, NULL, NULL);
+		if (!err)
+			for (i = 0; i < dpages.ndpage; i++) {
+				dpage = dpages.dpages + i;
+				ndentry = dpage->ndentry;
+				for (j = 0; j < ndentry; j++)
+					au_dpri_dentry(dpage->dentries[j]);
+			}
+		au_dpages_free(&dpages);
+	} while (0);
+#endif
+
+#if 1
+	{
+		struct inode *i;
+
+		pr("isolated inode\n");
+		spin_lock(&inode_sb_list_lock);
+		list_for_each_entry(i, &sb->s_inodes, i_sb_list) {
+			spin_lock(&i->i_lock);
+			if (1 || hlist_empty(&i->i_dentry))
+				au_dpri_inode(i);
+			spin_unlock(&i->i_lock);
+		}
+		spin_unlock(&inode_sb_list_lock);
+	}
+#endif
+	pr("files\n");
+	files = &au_sbi(sb)->si_files;
+	spin_lock(&files->spin);
+	hlist_for_each_entry(finfo, &files->head, fi_hlist) {
+		umode_t mode;
+
+		file = finfo->fi_file;
+		mode = file_inode(file)->i_mode;
+		if (!special_file(mode))
+			au_dpri_file(file);
+	}
+	spin_unlock(&files->spin);
+	pr("done\n");
+
+#undef pr
+	au_plevel = plevel;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* module parameter */
+static char *aufs_sysrq_key = "a";
+module_param_named(sysrq, aufs_sysrq_key, charp, S_IRUGO);
+MODULE_PARM_DESC(sysrq, "MagicSysRq key for " AUFS_NAME);
+
+static void au_sysrq(int key __maybe_unused)
+{
+	struct au_sbinfo *sbinfo;
+
+	lockdep_off();
+	au_sbilist_lock();
+	list_for_each_entry(sbinfo, &au_sbilist.head, si_list)
+		sysrq_sb(sbinfo->si_sb);
+	au_sbilist_unlock();
+	lockdep_on();
+}
+
+static struct sysrq_key_op au_sysrq_op = {
+	.handler	= au_sysrq,
+	.help_msg	= "Aufs",
+	.action_msg	= "Aufs",
+	.enable_mask	= SYSRQ_ENABLE_DUMP
+};
+
+/* ---------------------------------------------------------------------- */
+
+int __init au_sysrq_init(void)
+{
+	int err;
+	char key;
+
+	err = -1;
+	key = *aufs_sysrq_key;
+	if ('a' <= key && key <= 'z')
+		err = register_sysrq_key(key, &au_sysrq_op);
+	if (unlikely(err))
+		pr_err("err %d, sysrq=%c\n", err, key);
+	return err;
+}
+
+void au_sysrq_fin(void)
+{
+	int err;
+
+	err = unregister_sysrq_key(*aufs_sysrq_key, &au_sysrq_op);
+	if (unlikely(err))
+		pr_err("err %d (ignored)\n", err);
+}