dlm: fix malfunction of dlm_tool caused by debugfs changes
With the current kernel, `dlm_tool lockdebug` fails as below:
"dlm_tool lockdebug ED0BD86DCE724393918A1AE8FDBF1EE3
can't open /sys/kernel/debug/dlm/ED0BD86DCE724393918A1AE8FDBF1EE3:
Operation not permitted"
This is because table_open() depends on file->f_op to tell which
seq_file ops should be passed down. But, the original file ops in
file->f_op is replaced by "debugfs_full_proxy_file_operations" with
commit 49d200deaa68 ("debugfs: prevent access to removed files'
private data").
Currently, I can think up 2 solutions: 1st, replace
debugfs_create_file() with debugfs_create_file_unsafe();
2nd, make different table_open#() accordingly. The 1st one
is neat, but I don't thoroughly understand its risk. Maybe
someone has a better one.
Signed-off-by: Eric Ren <zren@suse.com>
Signed-off-by: David Teigland <teigland@redhat.com>
diff --git a/fs/dlm/debug_fs.c b/fs/dlm/debug_fs.c
index eea6491..466f7d6 100644
--- a/fs/dlm/debug_fs.c
+++ b/fs/dlm/debug_fs.c
@@ -607,20 +607,54 @@
static const struct file_operations format3_fops;
static const struct file_operations format4_fops;
-static int table_open(struct inode *inode, struct file *file)
+static int table_open1(struct inode *inode, struct file *file)
{
struct seq_file *seq;
- int ret = -1;
+ int ret;
- if (file->f_op == &format1_fops)
- ret = seq_open(file, &format1_seq_ops);
- else if (file->f_op == &format2_fops)
- ret = seq_open(file, &format2_seq_ops);
- else if (file->f_op == &format3_fops)
- ret = seq_open(file, &format3_seq_ops);
- else if (file->f_op == &format4_fops)
- ret = seq_open(file, &format4_seq_ops);
+ ret = seq_open(file, &format1_seq_ops);
+ if (ret)
+ return ret;
+ seq = file->private_data;
+ seq->private = inode->i_private; /* the dlm_ls */
+ return 0;
+}
+
+static int table_open2(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq;
+ int ret;
+
+ ret = seq_open(file, &format2_seq_ops);
+ if (ret)
+ return ret;
+
+ seq = file->private_data;
+ seq->private = inode->i_private; /* the dlm_ls */
+ return 0;
+}
+
+static int table_open3(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq;
+ int ret;
+
+ ret = seq_open(file, &format3_seq_ops);
+ if (ret)
+ return ret;
+
+ seq = file->private_data;
+ seq->private = inode->i_private; /* the dlm_ls */
+ return 0;
+}
+
+static int table_open4(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq;
+ int ret;
+
+ ret = seq_open(file, &format4_seq_ops);
if (ret)
return ret;
@@ -631,7 +665,7 @@
static const struct file_operations format1_fops = {
.owner = THIS_MODULE,
- .open = table_open,
+ .open = table_open1,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release
@@ -639,7 +673,7 @@
static const struct file_operations format2_fops = {
.owner = THIS_MODULE,
- .open = table_open,
+ .open = table_open2,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release
@@ -647,7 +681,7 @@
static const struct file_operations format3_fops = {
.owner = THIS_MODULE,
- .open = table_open,
+ .open = table_open3,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release
@@ -655,7 +689,7 @@
static const struct file_operations format4_fops = {
.owner = THIS_MODULE,
- .open = table_open,
+ .open = table_open4,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release