proc: introduce proc_create_single{,_data}

Variants of proc_create{,_data} that directly take a seq_file show
callback and drastically reduces the boilerplate code in the callers.

All trivial callers converted over.

Signed-off-by: Christoph Hellwig <hch@lst.de>

kernel/cgroup/cgroup-internal.h

@@ -218,9 +218,9 @@ extern const struct proc_ns_operations cgroupns_operations;
  * cgroup-v1.c
  */
 extern struct cftype cgroup1_base_files[];
-extern const struct file_operations proc_cgroupstats_operations;
 extern struct kernfs_syscall_ops cgroup1_kf_syscall_ops;
 
+int proc_cgroupstats_show(struct seq_file *m, void *v);
 bool cgroup1_ssid_disabled(int ssid);
 void cgroup1_pidlist_destroy_all(struct cgroup *cgrp);
 void cgroup1_release_agent(struct work_struct *work);

kernel/cgroup/cgroup-v1.c

@@ -682,7 +682,7 @@ struct cftype cgroup1_base_files[] = {
 };
 
 /* Display information about each subsystem and each hierarchy */
-static int proc_cgroupstats_show(struct seq_file *m, void *v)
+int proc_cgroupstats_show(struct seq_file *m, void *v)
 {
 	struct cgroup_subsys *ss;
 	int i;
@@ -705,18 +705,6 @@ static int proc_cgroupstats_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static int cgroupstats_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, proc_cgroupstats_show, NULL);
-}
-
-const struct file_operations proc_cgroupstats_operations = {
-	.open = cgroupstats_open,
-	.read = seq_read,
-	.llseek = seq_lseek,
-	.release = single_release,
-};
-
 /**
  * cgroupstats_build - build and fill cgroupstats
  * @stats: cgroupstats to fill information into

kernel/cgroup/cgroup.c

@@ -5335,7 +5335,7 @@ int __init cgroup_init(void)
 	WARN_ON(sysfs_create_mount_point(fs_kobj, "cgroup"));
 	WARN_ON(register_filesystem(&cgroup_fs_type));
 	WARN_ON(register_filesystem(&cgroup2_fs_type));
-	WARN_ON(!proc_create("cgroups", 0, NULL, &proc_cgroupstats_operations));
+	WARN_ON(!proc_create_single("cgroups", 0, NULL, proc_cgroupstats_show));
 
 	return 0;
 }

kernel/dma.c

@@ -135,21 +135,9 @@ static int proc_dma_show(struct seq_file *m, void *v)
 }
 #endif /* MAX_DMA_CHANNELS */
 
-static int proc_dma_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, proc_dma_show, NULL);
-}
-
-static const struct file_operations proc_dma_operations = {
-	.open		= proc_dma_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
 static int __init proc_dma_init(void)
 {
-	proc_create("dma", 0, NULL, &proc_dma_operations);
+	proc_create_single("dma", 0, NULL, proc_dma_show);
 	return 0;
 }
 

kernel/exec_domain.c

@@ -27,21 +27,9 @@ static int execdomains_proc_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static int execdomains_proc_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, execdomains_proc_show, NULL);
-}
-
-static const struct file_operations execdomains_proc_fops = {
-	.open		= execdomains_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
 static int __init proc_execdomains_init(void)
 {
-	proc_create("execdomains", 0, NULL, &execdomains_proc_fops);
+	proc_create_single("execdomains", 0, NULL, execdomains_proc_show);
 	return 0;
 }
 module_init(proc_execdomains_init);

kernel/irq/proc.c

@@ -185,11 +185,6 @@ static int irq_affinity_list_proc_open(struct inode *inode, struct file *file)
 	return single_open(file, irq_affinity_list_proc_show, PDE_DATA(inode));
 }
 
-static int irq_affinity_hint_proc_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, irq_affinity_hint_proc_show, PDE_DATA(inode));
-}
-
 static const struct file_operations irq_affinity_proc_fops = {
 	.open		= irq_affinity_proc_open,
 	.read		= seq_read,
@@ -198,13 +193,6 @@ static const struct file_operations irq_affinity_proc_fops = {
 	.write		= irq_affinity_proc_write,
 };
 
-static const struct file_operations irq_affinity_hint_proc_fops = {
-	.open		= irq_affinity_hint_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
 static const struct file_operations irq_affinity_list_proc_fops = {
 	.open		= irq_affinity_list_proc_open,
 	.read		= seq_read,
@@ -223,32 +211,6 @@ static int irq_effective_aff_list_proc_show(struct seq_file *m, void *v)
 {
 	return show_irq_affinity(EFFECTIVE_LIST, m);
 }
-
-static int irq_effective_aff_proc_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, irq_effective_aff_proc_show, PDE_DATA(inode));
-}
-
-static int irq_effective_aff_list_proc_open(struct inode *inode,
-					    struct file *file)
-{
-	return single_open(file, irq_effective_aff_list_proc_show,
-			   PDE_DATA(inode));
-}
-
-static const struct file_operations irq_effective_aff_proc_fops = {
-	.open		= irq_effective_aff_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
-static const struct file_operations irq_effective_aff_list_proc_fops = {
-	.open		= irq_effective_aff_list_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
 #endif
 
 static int default_affinity_show(struct seq_file *m, void *v)
@@ -313,18 +275,6 @@ static int irq_node_proc_show(struct seq_file *m, void *v)
 	seq_printf(m, "%d\n", irq_desc_get_node(desc));
 	return 0;
 }
-
-static int irq_node_proc_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, irq_node_proc_show, PDE_DATA(inode));
-}
-
-static const struct file_operations irq_node_proc_fops = {
-	.open		= irq_node_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
 #endif
 
 static int irq_spurious_proc_show(struct seq_file *m, void *v)
@@ -337,18 +287,6 @@ static int irq_spurious_proc_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static int irq_spurious_proc_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, irq_spurious_proc_show, PDE_DATA(inode));
-}
-
-static const struct file_operations irq_spurious_proc_fops = {
-	.open		= irq_spurious_proc_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
 #define MAX_NAMELEN 128
 
 static int name_unique(unsigned int irq, struct irqaction *new_action)
@@ -421,24 +359,24 @@ void register_irq_proc(unsigned int irq, struct irq_desc *desc)
 			 &irq_affinity_proc_fops, irqp);
 
 	/* create /proc/irq/<irq>/affinity_hint */
-	proc_create_data("affinity_hint", 0444, desc->dir,
-			 &irq_affinity_hint_proc_fops, irqp);
+	proc_create_single_data("affinity_hint", 0444, desc->dir,
+			irq_affinity_hint_proc_show, irqp);
 
 	/* create /proc/irq/<irq>/smp_affinity_list */
 	proc_create_data("smp_affinity_list", 0644, desc->dir,
 			 &irq_affinity_list_proc_fops, irqp);
 
-	proc_create_data("node", 0444, desc->dir,
-			 &irq_node_proc_fops, irqp);
+	proc_create_single_data("node", 0444, desc->dir, irq_node_proc_show,
+			irqp);
 # ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK
-	proc_create_data("effective_affinity", 0444, desc->dir,
-			 &irq_effective_aff_proc_fops, irqp);
-	proc_create_data("effective_affinity_list", 0444, desc->dir,
-			 &irq_effective_aff_list_proc_fops, irqp);
+	proc_create_single_data("effective_affinity", 0444, desc->dir,
+			irq_effective_aff_proc_show, irqp);
+	proc_create_single_data("effective_affinity_list", 0444, desc->dir,
+			irq_effective_aff_list_proc_show, irqp);
 # endif
 #endif
-	proc_create_data("spurious", 0444, desc->dir,
-			 &irq_spurious_proc_fops, (void *)(long)irq);
+	proc_create_single_data("spurious", 0444, desc->dir,
+			irq_spurious_proc_show, (void *)(long)irq);
 
 out_unlock:
 	mutex_unlock(&register_lock);

kernel/locking/lockdep_proc.c

@@ -331,18 +331,6 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static int lockdep_stats_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, lockdep_stats_show, NULL);
-}
-
-static const struct file_operations proc_lockdep_stats_operations = {
-	.open		= lockdep_stats_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= single_release,
-};
-
 #ifdef CONFIG_LOCK_STAT
 
 struct lock_stat_data {
@@ -662,9 +650,7 @@ static int __init lockdep_proc_init(void)
 #ifdef CONFIG_PROVE_LOCKING
 	proc_create_seq("lockdep_chains", S_IRUSR, NULL, &lockdep_chains_ops);
 #endif
-	proc_create("lockdep_stats", S_IRUSR, NULL,
-		    &proc_lockdep_stats_operations);
-
+	proc_create_single("lockdep_stats", S_IRUSR, NULL, lockdep_stats_show);
 #ifdef CONFIG_LOCK_STAT
 	proc_create("lock_stat", S_IRUSR | S_IWUSR, NULL,
 		    &proc_lock_stat_operations);