staging: android: logger: Allocate logs dynamically at boot (v3)

This changes the log initialization to be dynamic, but still
at boot time.  These changes are a predecessor to implementing
runtime allocation and freeing of logs, to make the Android logger
less hard-coded.

Change from a fixed set of static log structures, to allocation
at init time into a list.  Return proper error numbers on log
allocation failure.

Cc: Brian Swetland <swetland@google.com>
Signed-off-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tim Bird 2012-05-10 15:11:36 -07:00 committed by Greg Kroah-Hartman
parent 9a0fbbb52a
commit 10b241991f
1 changed files with 63 additions and 46 deletions

View File

@ -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, \
};
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)
static struct logger_log *get_log_from_minor(int minor)
static int __init create_log(char *log_name, int size)
{
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;
int ret = 0;
struct logger_log *log;
unsigned char *buffer;
buffer = vmalloc(size);
if (buffer == NULL)
return -ENOMEM;
log = kzalloc(sizeof(struct logger_log), GFP_KERNEL);
if (log == NULL) {
ret = -ENOMEM;
goto out_free_buffer;
}
log->buffer = buffer;
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;
}
static int __init init_log(struct logger_log *log)
{
int ret;
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;