staging: android: logger: Allocate logs dynamically at boot (v3) (10b24199) · Commits · 戴 / test

drivers/staging/android/logger.c

+62 −45

Original line number	Diff line number	Diff line
		@@ -25,6 +25,7 @@
		#include <linux/poll.h>
		#include <linux/slab.h>
		#include <linux/time.h>
		#include <linux/vmalloc.h>
		#include "logger.h"

		#include <asm/ioctls.h>
		@@ -45,8 +46,12 @@ struct logger_log {
		size_t w_off; /* current write head offset */
		size_t head; /* new readers start here */
		size_t size; /* size of the log */
		struct list_head logs; /* list of log channels (myself)*/
		};

		static LIST_HEAD(log_list);


		/*
		* struct logger_reader - a logging device open for reading
		*
		@@ -408,7 +413,15 @@ ssize_t logger_aio_write(struct kiocb iocb, const struct iovec iov,
		return ret;
		}

		static struct logger_log *get_log_from_minor(int);
		static struct logger_log *get_log_from_minor(int minor)
		{
		struct logger_log *log;

		list_for_each_entry(log, &log_list, logs)
		if (log->misc.minor == minor)
		return log;
		return NULL;
		}

		/*
		* logger_open - the log's open() file operation
		@@ -565,80 +578,84 @@ static const struct file_operations logger_fops = {
		};

		/*
		* Defines a log structure with name 'NAME' and a size of 'SIZE' bytes, which
		* must be a power of two, greater than LOGGER_ENTRY_MAX_LEN, and less than
		* LONG_MAX minus LOGGER_ENTRY_MAX_LEN.
		* Log size must be a power of two, greater than LOGGER_ENTRY_MAX_LEN,
		* and less than LONG_MAX minus LOGGER_ENTRY_MAX_LEN.
		*/
		#define DEFINE_LOGGER_DEVICE(VAR, NAME, SIZE) \
		static unsigned char _buf_ ## VAR[SIZE]; \
		static struct logger_log VAR = { \
		.buffer = _buf_ ## VAR, \
		.misc = { \
		.minor = MISC_DYNAMIC_MINOR, \
		.name = NAME, \
		.fops = &logger_fops, \
		.parent = NULL, \
		}, \
		.wq = __WAIT_QUEUE_HEAD_INITIALIZER(VAR .wq), \
		.readers = LIST_HEAD_INIT(VAR .readers), \
		.mutex = __MUTEX_INITIALIZER(VAR .mutex), \
		.w_off = 0, \
		.head = 0, \
		.size = SIZE, \
		};
		static int __init create_log(char *log_name, int size)
		{
		int ret = 0;
		struct logger_log *log;
		unsigned char *buffer;

		DEFINE_LOGGER_DEVICE(log_main, LOGGER_LOG_MAIN, 256*1024)
		DEFINE_LOGGER_DEVICE(log_events, LOGGER_LOG_EVENTS, 256*1024)
		DEFINE_LOGGER_DEVICE(log_radio, LOGGER_LOG_RADIO, 256*1024)
		DEFINE_LOGGER_DEVICE(log_system, LOGGER_LOG_SYSTEM, 256*1024)
		buffer = vmalloc(size);
		if (buffer == NULL)
		return -ENOMEM;

		static struct logger_log *get_log_from_minor(int minor)
		{
		if (log_main.misc.minor == minor)
		return &log_main;
		if (log_events.misc.minor == minor)
		return &log_events;
		if (log_radio.misc.minor == minor)
		return &log_radio;
		if (log_system.misc.minor == minor)
		return &log_system;
		return NULL;
		log = kzalloc(sizeof(struct logger_log), GFP_KERNEL);
		if (log == NULL) {
		ret = -ENOMEM;
		goto out_free_buffer;
		}
		log->buffer = buffer;

		static int __init init_log(struct logger_log *log)
		{
		int ret;
		log->misc.minor = MISC_DYNAMIC_MINOR;
		log->misc.name = kstrdup(log_name, GFP_KERNEL);
		if (log->misc.name == NULL) {
		ret = -ENOMEM;
		goto out_free_log;
		}

		log->misc.fops = &logger_fops;
		log->misc.parent = NULL;

		init_waitqueue_head(&log->wq);
		INIT_LIST_HEAD(&log->readers);
		mutex_init(&log->mutex);
		log->w_off = 0;
		log->head = 0;
		log->size = size;

		INIT_LIST_HEAD(&log->logs);
		list_add_tail(&log->logs, &log_list);

		/* finally, initialize the misc device for this log */
		ret = misc_register(&log->misc);
		if (unlikely(ret)) {
		printk(KERN_ERR "logger: failed to register misc "
		"device for log '%s'!\n", log->misc.name);
		return ret;
		goto out_free_log;
		}

		printk(KERN_INFO "logger: created %luK log '%s'\n",
		(unsigned long) log->size >> 10, log->misc.name);

		return 0;

		out_free_log:
		kfree(log);

		out_free_buffer:
		vfree(buffer);
		return ret;
		}

		static int __init logger_init(void)
		{
		int ret;

		ret = init_log(&log_main);
		ret = create_log(LOGGER_LOG_MAIN, 256*1024);
		if (unlikely(ret))
		goto out;

		ret = init_log(&log_events);
		ret = create_log(LOGGER_LOG_EVENTS, 256*1024);
		if (unlikely(ret))
		goto out;

		ret = init_log(&log_radio);
		ret = create_log(LOGGER_LOG_RADIO, 256*1024);
		if (unlikely(ret))
		goto out;

		ret = init_log(&log_system);
		ret = create_log(LOGGER_LOG_SYSTEM, 256*1024);
		if (unlikely(ret))
		goto out;

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