[PATCH 21/40] afs: simplify procfs code

[Christoph Hellwig]

Use remove_proc_subtree to remove the whole subtree on cleanup, and
unwind the registration loop into individual calls.  Switch to use
proc_create_seq where applicable.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
 fs/afs/proc.c | 134 ++++++--------------------------------------------
 1 file changed, 15 insertions(+), 119 deletions(-)

diff --git a/fs/afs/proc.c b/fs/afs/proc.c
index 839a22280606..3aad32762989 100644
--- a/fs/afs/proc.c
+++ b/fs/afs/proc.c
@@ -62,7 +62,6 @@ static const struct file_operations afs_proc_rootcell_fops = {
 	.llseek		= no_llseek,
 };
 
-static int afs_proc_cell_volumes_open(struct inode *inode, struct file *file);
 static void *afs_proc_cell_volumes_start(struct seq_file *p, loff_t *pos);
 static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
 					loff_t *pos);
@@ -76,15 +75,6 @@ static const struct seq_operations afs_proc_cell_volumes_ops = {
 	.show	= afs_proc_cell_volumes_show,
 };
 
-static const struct file_operations afs_proc_cell_volumes_fops = {
-	.open		= afs_proc_cell_volumes_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release,
-};
-
-static int afs_proc_cell_vlservers_open(struct inode *inode,
-					struct file *file);
 static void *afs_proc_cell_vlservers_start(struct seq_file *p, loff_t *pos);
 static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
 					  loff_t *pos);
@@ -98,14 +88,6 @@ static const struct seq_operations afs_proc_cell_vlservers_ops = {
 	.show	= afs_proc_cell_vlservers_show,
 };
 
-static const struct file_operations afs_proc_cell_vlservers_fops = {
-	.open		= afs_proc_cell_vlservers_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release,
-};
-
-static int afs_proc_servers_open(struct inode *inode, struct file *file);
 static void *afs_proc_servers_start(struct seq_file *p, loff_t *pos);
 static void *afs_proc_servers_next(struct seq_file *p, void *v,
 					loff_t *pos);
@@ -119,13 +101,6 @@ static const struct seq_operations afs_proc_servers_ops = {
 	.show	= afs_proc_servers_show,
 };
 
-static const struct file_operations afs_proc_servers_fops = {
-	.open		= afs_proc_servers_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release,
-};
-
 static int afs_proc_sysname_open(struct inode *inode, struct file *file);
 static int afs_proc_sysname_release(struct inode *inode, struct file *file);
 static void *afs_proc_sysname_start(struct seq_file *p, loff_t *pos);
@@ -152,7 +127,7 @@ static const struct file_operations afs_proc_sysname_fops = {
 	.write		= afs_proc_sysname_write,
 };
 
-static const struct file_operations afs_proc_stats_fops;
+static int afs_proc_stats_show(struct seq_file *m, void *v);
 
 /*
  * initialise the /proc/fs/afs/ directory
@@ -167,8 +142,8 @@ int afs_proc_init(struct afs_net *net)
 
 	if (!proc_create("cells", 0644, net->proc_afs, &afs_proc_cells_fops) ||
 	    !proc_create("rootcell", 0644, net->proc_afs, &afs_proc_rootcell_fops) ||
-	    !proc_create("servers", 0644, net->proc_afs, &afs_proc_servers_fops) ||
-	    !proc_create("stats", 0644, net->proc_afs, &afs_proc_stats_fops) ||
+	    !proc_create_seq("servers", 0644, net->proc_afs, &afs_proc_servers_ops) ||
+	    !proc_create_single("stats", 0644, net->proc_afs, afs_proc_stats_show) ||
 	    !proc_create("sysname", 0644, net->proc_afs, &afs_proc_sysname_fops))
 		goto error_tree;
 
@@ -196,16 +171,7 @@ void afs_proc_cleanup(struct afs_net *net)
  */
 static int afs_proc_cells_open(struct inode *inode, struct file *file)
 {
-	struct seq_file *m;
-	int ret;
-
-	ret = seq_open(file, &afs_proc_cells_ops);
-	if (ret < 0)
-		return ret;
-
-	m = file->private_data;
-	m->private = PDE_DATA(inode);
-	return 0;
+	return seq_open(file, &afs_proc_cells_ops);
 }
 
 /*
@@ -430,10 +396,11 @@ int afs_proc_cell_setup(struct afs_net *net, struct afs_cell *cell)
 	if (!dir)
 		goto error_dir;
 
-	if (!proc_create_data("vlservers", 0, dir,
-			      &afs_proc_cell_vlservers_fops, cell) ||
-	    !proc_create_data("volumes", 0, dir,
-			      &afs_proc_cell_volumes_fops, cell))
+	if (!proc_create_seq_data("vlservers", 0, dir,
+			&afs_proc_cell_vlservers_ops, cell))
+		goto error_tree;
+	if (!proc_create_seq_data("volumes", 0, dir, &afs_proc_cell_volumes_ops,
+			cell))
 		goto error_tree;
 
 	_leave(" = 0");
@@ -458,29 +425,6 @@ void afs_proc_cell_remove(struct afs_net *net, struct afs_cell *cell)
 	_leave("");
 }
 
-/*
- * open "/proc/fs/afs/<cell>/volumes" which provides a summary of extant cells
- */
-static int afs_proc_cell_volumes_open(struct inode *inode, struct file *file)
-{
-	struct afs_cell *cell;
-	struct seq_file *m;
-	int ret;
-
-	cell = PDE_DATA(inode);
-	if (!cell)
-		return -ENOENT;
-
-	ret = seq_open(file, &afs_proc_cell_volumes_ops);
-	if (ret < 0)
-		return ret;
-
-	m = file->private_data;
-	m->private = cell;
-
-	return 0;
-}
-
 /*
  * set up the iterator to start reading from the cells list and return the
  * first item
@@ -488,7 +432,7 @@ static int afs_proc_cell_volumes_open(struct inode *inode, struct file *file)
 static void *afs_proc_cell_volumes_start(struct seq_file *m, loff_t *_pos)
 	__acquires(cell->proc_lock)
 {
-	struct afs_cell *cell = m->private;
+	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
 
 	_enter("cell=%p pos=%Ld", cell, *_pos);
 
@@ -502,7 +446,7 @@ static void *afs_proc_cell_volumes_start(struct seq_file *m, loff_t *_pos)
 static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
 					loff_t *_pos)
 {
-	struct afs_cell *cell = p->private;
+	struct afs_cell *cell = PDE_DATA(file_inode(p->file));
 
 	_enter("cell=%p pos=%Ld", cell, *_pos);
 	return seq_list_next(v, &cell->proc_volumes, _pos);
@@ -514,7 +458,7 @@ static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
 static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v)
 	__releases(cell->proc_lock)
 {
-	struct afs_cell *cell = p->private;
+	struct afs_cell *cell = PDE_DATA(file_inode(p->file));
 
 	read_unlock(&cell->proc_lock);
 }
@@ -530,7 +474,7 @@ static const char afs_vol_types[3][3] = {
  */
 static int afs_proc_cell_volumes_show(struct seq_file *m, void *v)
 {
-	struct afs_cell *cell = m->private;
+	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
 	struct afs_volume *vol = list_entry(v, struct afs_volume, proc_link);
 
 	/* Display header on line 1 */
@@ -546,30 +490,6 @@ static int afs_proc_cell_volumes_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-/*
- * open "/proc/fs/afs/<cell>/vlservers" which provides a list of volume
- * location server
- */
-static int afs_proc_cell_vlservers_open(struct inode *inode, struct file *file)
-{
-	struct afs_cell *cell;
-	struct seq_file *m;
-	int ret;
-
-	cell = PDE_DATA(inode);
-	if (!cell)
-		return -ENOENT;
-
-	ret = seq_open(file, &afs_proc_cell_vlservers_ops);
-	if (ret<0)
-		return ret;
-
-	m = file->private_data;
-	m->private = cell;
-
-	return 0;
-}
-
 /*
  * set up the iterator to start reading from the cells list and return the
  * first item
@@ -578,7 +498,7 @@ static void *afs_proc_cell_vlservers_start(struct seq_file *m, loff_t *_pos)
 	__acquires(rcu)
 {
 	struct afs_addr_list *alist;
-	struct afs_cell *cell = m->private;
+	struct afs_cell *cell = PDE_DATA(file_inode(m->file));
 	loff_t pos = *_pos;
 
 	rcu_read_lock();
@@ -603,7 +523,7 @@ static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
 					  loff_t *_pos)
 {
 	struct afs_addr_list *alist;
-	struct afs_cell *cell = p->private;
+	struct afs_cell *cell = PDE_DATA(file_inode(p->file));
 	loff_t pos;
 
 	alist = rcu_dereference(cell->vl_addrs);
@@ -643,15 +563,6 @@ static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-/*
- * open "/proc/fs/afs/servers" which provides a summary of active
- * servers
- */
-static int afs_proc_servers_open(struct inode *inode, struct file *file)
-{
-	return seq_open(file, &afs_proc_servers_ops);
-}
-
 /*
  * Set up the iterator to start reading from the server list and return the
  * first item.
@@ -931,18 +842,3 @@ static int afs_proc_stats_show(struct seq_file *m, void *v)
 		   atomic_long_read(&net->n_store_bytes));
 	return 0;
 }
-
-/*
- * Open "/proc/fs/afs/stats" to allow reading of the stat counters.
- */
-static int afs_proc_stats_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, afs_proc_stats_show, NULL);
-}
-
-static const struct file_operations afs_proc_stats_fops = {
-	.open		= afs_proc_stats_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release        = single_release,
-};
-- 
2.17.0