proc: introduce proc_create_seq{,_data}

Variants of proc_create{,_data} that directly take a struct seq_operations
argument and drastically reduces the boilerplate code in the callers.

All trivial callers converted over.

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

fs/fscache/histogram.c

@@ -83,24 +83,9 @@ static void fscache_histogram_stop(struct seq_file *m, void *v)
 {
 }
 
-static const struct seq_operations fscache_histogram_ops = {
+const struct seq_operations fscache_histogram_ops = {
 	.start		= fscache_histogram_start,
 	.stop		= fscache_histogram_stop,
 	.next		= fscache_histogram_next,
 	.show		= fscache_histogram_show,
 };
-
-/*
- * open "/proc/fs/fscache/histogram" to provide latency data
- */
-static int fscache_histogram_open(struct inode *inode, struct file *file)
-{
-	return seq_open(file, &fscache_histogram_ops);
-}
-
-const struct file_operations fscache_histogram_fops = {
-	.open		= fscache_histogram_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= seq_release,
-};

fs/fscache/internal.h

@@ -31,6 +31,7 @@
 #include <linux/fscache-cache.h>
 #include <trace/events/fscache.h>
 #include <linux/sched.h>
+#include <linux/seq_file.h>
 
 #define FSCACHE_MIN_THREADS	4
 #define FSCACHE_MAX_THREADS	32
@@ -84,7 +85,7 @@ static inline void fscache_hist(atomic_t histogram[], unsigned long start_jif)
 	atomic_inc(&histogram[jif]);
 }
 
-extern const struct file_operations fscache_histogram_fops;
+extern const struct seq_operations fscache_histogram_ops;
 
 #else
 #define fscache_hist(hist, start_jif) do {} while (0)

fs/fscache/proc.c

@@ -32,8 +32,8 @@ int __init fscache_proc_init(void)
 #endif
 
 #ifdef CONFIG_FSCACHE_HISTOGRAM
-	if (!proc_create("fs/fscache/histogram", S_IFREG | 0444, NULL,
-			 &fscache_histogram_fops))
+	if (!proc_create_seq("fs/fscache/histogram", S_IFREG | 0444, NULL,
+			 &fscache_histogram_ops))
 		goto error_histogram;
 #endif