[PATCH 15/28] reiserfs: Don't access the proc_dir_entry in r_open(),r_start() r_show() [RFC]

From: David Howells
Date: Tue Apr 16 2013 - 14:26:59 EST


Don't access the proc_dir_entry in ReiserFS's r_open(), r_start() r_show()
procfs interface functions.

ReiserFS stores the ->show() method pointer in PDE->data and the super_block
pointer in PDE->parent->data. This isn't changing.

Currently, ReiserFS passes the PDE pointer into seq_file::private from
r_open() so that r_start() and r_show() can then access it. Instead, use
seq_open_private() to allocate a two-pointer struct that's passed through
seq_file::private and put the ->show() method and the sb pointers in there.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: reiserfs-devel@xxxxxxxxxxxxxxx
---

fs/reiserfs/procfs.c | 32 +++++++++++++++++++-------------
1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/fs/reiserfs/procfs.c b/fs/reiserfs/procfs.c
index 274adea..33532f7 100644
--- a/fs/reiserfs/procfs.c
+++ b/fs/reiserfs/procfs.c
@@ -394,20 +394,24 @@ static int set_sb(struct super_block *sb, void *data)
return -ENOENT;
}

+struct reiserfs_seq_private {
+ struct super_block *sb;
+ int (*show) (struct seq_file *, struct super_block *);
+};
+
static void *r_start(struct seq_file *m, loff_t * pos)
{
- struct proc_dir_entry *de = m->private;
- struct super_block *s = de->parent->data;
+ struct reiserfs_seq_private *priv = m->private;
loff_t l = *pos;

if (l)
return NULL;

- if (IS_ERR(sget(&reiserfs_fs_type, test_sb, set_sb, 0, s)))
+ if (IS_ERR(sget(&reiserfs_fs_type, test_sb, set_sb, 0, priv->sb)))
return NULL;

- up_write(&s->s_umount);
- return s;
+ up_write(&priv->sb->s_umount);
+ return priv->sb;
}

static void *r_next(struct seq_file *m, void *v, loff_t * pos)
@@ -426,9 +430,8 @@ static void r_stop(struct seq_file *m, void *v)

static int r_show(struct seq_file *m, void *v)
{
- struct proc_dir_entry *de = m->private;
- int (*show) (struct seq_file *, struct super_block *) = de->data;
- return show(m, v);
+ struct reiserfs_seq_private *priv = m->private;
+ return priv->show(m, v);
}

static const struct seq_operations r_ops = {
@@ -440,11 +443,15 @@ static const struct seq_operations r_ops = {

static int r_open(struct inode *inode, struct file *file)
{
- int ret = seq_open(file, &r_ops);
+ struct reiserfs_seq_private *priv;
+ int ret = seq_open_private(file, &r_ops,
+ sizeof(struct reiserfs_seq_private));

if (!ret) {
struct seq_file *m = file->private_data;
- m->private = PDE(inode);
+ priv = m->private;
+ priv->sb = proc_get_parent_data(inode);
+ priv->show = PDE_DATA(inode);
}
return ret;
}
@@ -453,7 +460,7 @@ static const struct file_operations r_file_operations = {
.open = r_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = seq_release,
+ .release = seq_release_private,
.owner = THIS_MODULE,
};

@@ -479,9 +486,8 @@ int reiserfs_proc_info_init(struct super_block *sb)
*s = '!';

spin_lock_init(&__PINFO(sb).lock);
- REISERFS_SB(sb)->procdir = proc_mkdir(b, proc_info_root);
+ REISERFS_SB(sb)->procdir = proc_mkdir_data(b, 0, proc_info_root, sb);
if (REISERFS_SB(sb)->procdir) {
- REISERFS_SB(sb)->procdir->data = sb;
add_file(sb, "version", show_version);
add_file(sb, "super", show_super);
add_file(sb, "per-level", show_per_level);

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