[PATCH 04/50] mars: add new file drivers/block/mars/brick_say.c

Thomas Schoebel-Theuer
2014-07-01T21:47:50Z

drivers/block/mars/brick_say.c | 931 +++++++++++++++++++++++++++++++++++++++++
1 file changed, 931 insertions(+)
create mode 100644 drivers/block/mars/brick_say.c

diff --git a/drivers/block/mars/brick_say.c b/drivers/block/mars/brick_say.c
new file mode 100644
index 0000000..09b975f
--- /dev/null
+++ b/drivers/block/mars/brick_say.c
@@ -0,0 +1,931 @@
+/* (c) 2010 Thomas Schoebel-Theuer / 1&1 Internet AG */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+
+#include <linux/brick/brick_say.h>
+#include <linux/brick/lamport.h>
+
+/*******************************************************************/
+
+/* messaging */
+
+#include <linux/fs.h>
+#include <linux/blkdev.h>
+#include <linux/file.h>
+#include <linux/sched.h>
+#include <linux/preempt.h>
+#include <linux/hardirq.h>
+#include <linux/smp.h>
+#include <linux/slab.h>
+#include <linux/kthread.h>
+#include <linux/syscalls.h>
+
+#include <linux/uaccess.h>
+
+#ifndef GFP_BRICK
+#define GFP_BRICK GFP_NOIO
+#endif
+
+#define SAY_ORDER 0
+#define SAY_BUFMAX (PAGE_SIZE << SAY_ORDER)
+#define SAY_BUF_LIMIT (SAY_BUFMAX - 1500)
+#define MAX_FILELEN 16
+#define MAX_IDS 1000
+
+const char *say_class[MAX_SAY_CLASS] = {
+ [SAY_DEBUG] = "debug",
+ [SAY_INFO] = "info",
+ [SAY_WARN] = "warn",
+ [SAY_ERROR] = "error",
+ [SAY_FATAL] = "fatal",
+ [SAY_TOTAL] = "total",
+};
+EXPORT_SYMBOL_GPL(say_class);
+
+int brick_say_logging = 1;
+EXPORT_SYMBOL_GPL(brick_say_logging);
+module_param_named(say_logging, brick_say_logging, int, 0);
+int brick_say_debug = 0;
+EXPORT_SYMBOL_GPL(brick_say_debug);
+module_param_named(say_debug, brick_say_debug, int, 0);
+
+int brick_say_syslog_min = 1;
+EXPORT_SYMBOL_GPL(brick_say_syslog_min);
+int brick_say_syslog_max = -1;
+EXPORT_SYMBOL_GPL(brick_say_syslog_max);
+int brick_say_syslog_flood_class = 3;
+EXPORT_SYMBOL_GPL(brick_say_syslog_flood_class);
+int brick_say_syslog_flood_limit = 20;
+EXPORT_SYMBOL_GPL(brick_say_syslog_flood_limit);
+int brick_say_syslog_flood_recovery = 300;
+EXPORT_SYMBOL_GPL(brick_say_syslog_flood_recovery);
+int delay_say_on_overflow =
+#ifdef CONFIG_MARS_DEBUG
+ 1;
+#else
+ 0;
+#endif
+EXPORT_SYMBOL_GPL(delay_say_on_overflow);
+
+static atomic_t say_alloc_channels = ATOMIC_INIT(0);
+static atomic_t say_alloc_names = ATOMIC_INIT(0);
+static atomic_t say_alloc_pages = ATOMIC_INIT(0);
+
+static unsigned long flood_start_jiffies;
+static int flood_count;
+
+struct say_channel {
+ char *ch_name;
+ struct say_channel *ch_next;
+ spinlock_t ch_lock[MAX_SAY_CLASS];
+ char *ch_buf[MAX_SAY_CLASS][2];
+
+ short ch_index[MAX_SAY_CLASS];
+ struct file *ch_filp[MAX_SAY_CLASS][2];
+ int ch_overflow[MAX_SAY_CLASS];
+ bool ch_written[MAX_SAY_CLASS];
+ bool ch_rollover;
+ bool ch_must_exist;
+ bool ch_is_dir;
+ bool ch_delete;
+ int ch_status_written;
+ int ch_id_max;
+ void *ch_ids[MAX_IDS];
+
+ wait_queue_head_t ch_progress;
+};
+
+struct say_channel *default_channel = NULL;
+EXPORT_SYMBOL_GPL(default_channel);
+
+static struct say_channel *channel_list;
+
+static rwlock_t say_lock = __RW_LOCK_UNLOCKED(say_lock);
+
+static struct task_struct *say_thread;
+
+static DECLARE_WAIT_QUEUE_HEAD(say_event);
+
+bool say_dirty = false;
+
+#define use_atomic() \
+ ((preempt_count() & (PREEMPT_MASK | SOFTIRQ_MASK | HARDIRQ_MASK | NMI_MASK)) != 0 || irqs_disabled())
+
+static
+void wait_channel(struct say_channel *ch, int class)
+{
+ if (delay_say_on_overflow && ch->ch_index[class] > SAY_BUF_LIMIT) {
+ if (!use_atomic()) {
+ say_dirty = true;
+ wake_up_interruptible(&say_event);
+ wait_event_interruptible_timeout(ch->ch_progress,
+ ch->ch_index[class] < SAY_BUF_LIMIT,
+ HZ / 10);
+ }
+ }
+}
+
+static
+struct say_channel *find_channel(const void *id)
+{
+ struct say_channel *res = default_channel;
+ struct say_channel *ch;
+
+ read_lock(&say_lock);
+ for (ch = channel_list; ch; ch = ch->ch_next) {
+ int i;
+
+ for (i = 0; i < ch->ch_id_max; i++) {
+ if (ch->ch_ids[i] == id) {
+ res = ch;
+ goto found;
+ }
+ }
+ }
+found:
+ read_unlock(&say_lock);
+ return res;
+}
+
+static
+void _remove_binding(struct task_struct *whom)
+{
+ struct say_channel *ch;
+ int i;
+
+ for (ch = channel_list; ch; ch = ch->ch_next) {
+ for (i = 0; i < ch->ch_id_max; i++) {
+ if (ch->ch_ids[i] == whom)
+ ch->ch_ids[i] = NULL;
+ }
+ }
+}
+
+void bind_to_channel(struct say_channel *ch, struct task_struct *whom)
+{
+ int i;
+
+ write_lock(&say_lock);
+ _remove_binding(whom);
+ for (i = 0; i < ch->ch_id_max; i++) {
+ if (!ch->ch_ids[i]) {
+ ch->ch_ids[i] = whom;
+ goto done;
+ }
+ }
+ if (likely(ch->ch_id_max < MAX_IDS - 1))
+ ch->ch_ids[ch->ch_id_max++] = whom;
+ else
+ goto err;
+done:
+ write_unlock(&say_lock);
+ goto out_return;
+err:
+ write_unlock(&say_lock);
+
+ say_to(default_channel, SAY_ERROR, "ID overflow for thread '%s'\n", whom->comm);
+out_return:;
+}
+EXPORT_SYMBOL_GPL(bind_to_channel);
+
+struct say_channel *get_binding(struct task_struct *whom)
+{
+ struct say_channel *ch;
+ int i;
+
+ read_lock(&say_lock);
+ for (ch = channel_list; ch; ch = ch->ch_next) {
+ for (i = 0; i < ch->ch_id_max; i++) {
+ if (ch->ch_ids[i] == whom)
+ goto found;
+ }
+ }
+ ch = NULL;
+found:
+ read_unlock(&say_lock);
+ return ch;
+}
+EXPORT_SYMBOL_GPL(get_binding);
+
+void remove_binding_from(struct say_channel *ch, struct task_struct *whom)
+{
+ bool found = false;
+ int i;
+
+ write_lock(&say_lock);
+ for (i = 0; i < ch->ch_id_max; i++) {
+ if (ch->ch_ids[i] == whom) {
+ ch->ch_ids[i] = NULL;
+ found = true;
+ break;
+ }
+ }
+ if (!found)
+ _remove_binding(whom);
+ write_unlock(&say_lock);
+}
+EXPORT_SYMBOL_GPL(remove_binding_from);
+
+void remove_binding(struct task_struct *whom)
+{
+ write_lock(&say_lock);
+ _remove_binding(whom);
+ write_unlock(&say_lock);
+}
+EXPORT_SYMBOL_GPL(remove_binding);
+
+void rollover_channel(struct say_channel *ch)
+{
+ if (!ch)
+ ch = find_channel(current);
+ if (likely(ch))
+ ch->ch_rollover = true;
+}
+EXPORT_SYMBOL_GPL(rollover_channel);
+
+void rollover_all(void)
+{
+ struct say_channel *ch;
+
+ read_lock(&say_lock);
+ for (ch = channel_list; ch; ch = ch->ch_next)
+ ch->ch_rollover = true;
+ read_unlock(&say_lock);
+}
+EXPORT_SYMBOL_GPL(rollover_all);
+
+void del_channel(struct say_channel *ch)
+{
+ if (unlikely(!ch))
+ goto out_return;
+ if (unlikely(ch == default_channel)) {
+ say_to(default_channel, SAY_ERROR, "thread '%s' tried to delete the default channel\n", current->comm);
+ goto out_return;
+ }
+
+ ch->ch_delete = true;
+out_return:;
+}
+EXPORT_SYMBOL_GPL(del_channel);
+
+static
+void _del_channel(struct say_channel *ch)
+{
+ struct say_channel *tmp;
+ struct say_channel **_tmp;
+ int i, j;
+
+ if (!ch)
+ goto out_return;
+ write_lock(&say_lock);
+ for (_tmp = &channel_list; (tmp = *_tmp) != NULL; _tmp = &tmp->ch_next) {
+ if (tmp == ch) {
+ *_tmp = tmp->ch_next;
+ break;
+ }
+ }
+ write_unlock(&say_lock);
+
+ for (i = 0; i < MAX_SAY_CLASS; i++) {
+ for (j = 0; j < 2; j++) {
+ if (ch->ch_filp[i][j]) {
+ filp_close(ch->ch_filp[i][j], NULL);
+ ch->ch_filp[i][j] = NULL;
+ }
+ }
+ for (j = 0; j < 2; j++) {
+ char *buf = ch->ch_buf[i][j];
+
+ if (buf) {
+ __free_pages(virt_to_page((unsigned long)buf), SAY_ORDER);
+ atomic_dec(&say_alloc_pages);
+ }
+ }
+ }
+ if (ch->ch_name) {
+ atomic_dec(&say_alloc_names);
+ kfree(ch->ch_name);
+ }
+ kfree(ch);
+ atomic_dec(&say_alloc_channels);
+out_return:;
+}
+
+static
+struct say_channel *_make_channel(const char *name, bool must_exist)
+{
+ struct say_channel *res = NULL;
+ struct kstat kstat = {};
+ int i, j;
+ unsigned long mode = use_atomic() ? GFP_ATOMIC : GFP_BRICK;
+
+ mm_segment_t oldfs;
+ bool is_dir = false;
+ int status;
+
+ oldfs = get_fs();
+ set_fs(get_ds());
+ status = vfs_stat((char *)name, &kstat);
+ set_fs(oldfs);
+
+ if (unlikely(status < 0)) {
+ if (must_exist) {
+ say(SAY_ERROR, "cannot create channel '%s', status = %d\n", name, status);
+ goto done;
+ }
+ } else {
+ is_dir = S_ISDIR(kstat.mode);
+ }
+
+restart:
+ res = kzalloc(sizeof(struct say_channel), mode);
+ if (unlikely(!res)) {
+ schedule();
+ goto restart;
+ }
+ atomic_inc(&say_alloc_channels);
+ res->ch_must_exist = must_exist;
+ res->ch_is_dir = is_dir;
+ init_waitqueue_head(&res->ch_progress);
+restart2:
+ res->ch_name = kstrdup(name, mode);
+ if (unlikely(!res->ch_name)) {
+ schedule();
+ goto restart2;
+ }
+ atomic_inc(&say_alloc_names);
+ for (i = 0; i < MAX_SAY_CLASS; i++) {
+ spin_lock_init(&res->ch_lock[i]);
+ for (j = 0; j < 2; j++) {
+ char *buf;
+
+restart3:
+ buf = (void *)__get_free_pages(mode, SAY_ORDER);
+ if (unlikely(!buf)) {
+ schedule();
+ goto restart3;
+ }
+ atomic_inc(&say_alloc_pages);
+ res->ch_buf[i][j] = buf;
+ }
+ }
+done:
+ return res;
+}
+
+struct say_channel *make_channel(const char *name, bool must_exist)
+{
+ struct say_channel *res = NULL;
+ struct say_channel *ch;
+
+ read_lock(&say_lock);
+ for (ch = channel_list; ch; ch = ch->ch_next) {
+ if (!strcmp(ch->ch_name, name)) {
+ res = ch;
+ break;
+ }
+ }
+ read_unlock(&say_lock);
+
+ if (unlikely(!res)) {
+ res = _make_channel(name, must_exist);
+ if (unlikely(!res))
+ goto done;
+
+ write_lock(&say_lock);
+
+ for (ch = channel_list; ch; ch = ch->ch_next) {
+ if (ch != res && unlikely(!strcmp(ch->ch_name, name))) {
+ _del_channel(res);
+ res = ch;
+ goto race_found;
+ }
+ }
+
+ res->ch_next = channel_list;
+ channel_list = res;
+
+race_found:
+ write_unlock(&say_lock);
+ }
+
+done:
+ return res;
+}
+EXPORT_SYMBOL_GPL(make_channel);
+
+/* tell gcc to check for varargs errors */
+static
+void _say(struct say_channel *ch, int class, va_list args, bool use_args, const char *fmt, ...) __printf(5, 6);
+
+static
+void _say(struct say_channel *ch, int class, va_list args, bool use_args, const char *fmt, ...)
+{
+ char *start;
+ int offset;
+ int rest;
+ int written;
+
+ if (unlikely(!ch))
+ goto out_return;
+ if (unlikely(ch->ch_delete && ch != default_channel)) {
+ say_to(default_channel, SAY_ERROR, "thread '%s' tried to write on deleted channel\n", current->comm);
+ goto out_return;
+ }
+
+ offset = ch->ch_index[class];
+ start = ch->ch_buf[class][0] + offset;
+ rest = SAY_BUFMAX - 1 - offset;
+ if (unlikely(rest <= 0)) {
+ ch->ch_overflow[class]++;
+ goto out_return;
+ }
+
+ if (use_args) {
+ va_list args2;
+
+ va_start(args2, fmt);
+ written = vscnprintf(start, rest, fmt, args2);
+ va_end(args2);
+ } else {
+ written = vscnprintf(start, rest, fmt, args);
+ }
+
+ if (likely(rest > written)) {
+ start[written] = '\0';
+ ch->ch_index[class] += written;
+ say_dirty = true;
+ } else {
+ /* indicate overflow */
+ start[0] = '\0';
+ ch->ch_overflow[class]++;
+ }
+out_return:;
+}
+
+void say_to(struct say_channel *ch, int class, const char *fmt, ...)
+{
+ va_list args;
+ unsigned long flags;
+
+ if (!class && !brick_say_debug)
+ goto out_return;
+ if (!ch)
+ ch = find_channel(current);
+
+ if (likely(ch)) {
+ if (!ch->ch_is_dir)
+ class = SAY_TOTAL;
+ if (likely(class >= 0 && class < MAX_SAY_CLASS)) {
+ wait_channel(ch, class);
+ spin_lock_irqsave(&ch->ch_lock[class], flags);
+
+ va_start(args, fmt);
+ _say(ch, class, args, false, fmt);
+ va_end(args);
+
+ spin_unlock_irqrestore(&ch->ch_lock[class], flags);
+ }
+ }
+
+ ch = default_channel;
+ if (likely(ch)) {
+ class = SAY_TOTAL;
+ wait_channel(ch, class);
+ spin_lock_irqsave(&ch->ch_lock[class], flags);
+
+ va_start(args, fmt);
+ _say(ch, class, args, false, fmt);
+ va_end(args);
+
+ spin_unlock_irqrestore(&ch->ch_lock[class], flags);
+
+ wake_up_interruptible(&say_event);
+ }
+out_return:;
+}
+EXPORT_SYMBOL_GPL(say_to);
+
+void brick_say_to(struct say_channel *ch,
+ int class,
+ bool dump,
+ const char *prefix,
+ const char *file,
+ int line,
+ const char *func,
+ const char *fmt,
+ ...)
+{
+ const char *channel_name = "-";
+ struct timespec s_now;
+ struct timespec l_now;
+ int filelen;
+ int orig_class;
+ va_list args;
+ unsigned long flags;
+
+ if (!class && !brick_say_debug)
+ goto out_return;
+ s_now = CURRENT_TIME;
+ get_lamport(&l_now);
+
+ if (!ch)
+ ch = find_channel(current);
+
+ orig_class = class;
+
+ /* limit the filename */
+ filelen = strlen(file);
+ if (filelen > MAX_FILELEN)
+ file += filelen - MAX_FILELEN;
+
+ if (likely(ch)) {
+ channel_name = ch->ch_name;
+ if (!ch->ch_is_dir)
+ class = SAY_TOTAL;
+ if (likely(class >= 0 && class < MAX_SAY_CLASS)) {
+ wait_channel(ch, class);
+ spin_lock_irqsave(&ch->ch_lock[class], flags);
+
+ _say(ch, class, NULL, true,
+ "%ld.%09ld %ld.%09ld %s %s[%d] %s:%d %s(): ",
+ s_now.tv_sec, s_now.tv_nsec,
+ l_now.tv_sec, l_now.tv_nsec,
+ prefix,
+ current->comm, (int)smp_processor_id(),
+ file, line,
+ func);
+
+ va_start(args, fmt);
+ _say(ch, class, args, false, fmt);
+ va_end(args);
+
+ spin_unlock_irqrestore(&ch->ch_lock[class], flags);
+ }
+ }
+
+ ch = default_channel;
+ if (likely(ch)) {
+ wait_channel(ch, SAY_TOTAL);
+ spin_lock_irqsave(&ch->ch_lock[SAY_TOTAL], flags);
+
+ _say(ch, SAY_TOTAL, NULL, true,
+ "%ld.%09ld %ld.%09ld %s_%-5s %s %s[%d] %s:%d %s(): ",
+ s_now.tv_sec, s_now.tv_nsec,
+ l_now.tv_sec, l_now.tv_nsec,
+ prefix, say_class[orig_class],
+ channel_name,
+ current->comm, (int)smp_processor_id(),
+ file, line,
+ func);
+
+ va_start(args, fmt);
+ _say(ch, SAY_TOTAL, args, false, fmt);
+ va_end(args);
+
+ spin_unlock_irqrestore(&ch->ch_lock[SAY_TOTAL], flags);
+
+ }
+#ifdef CONFIG_MARS_DEBUG
+ if (dump)
+ brick_dump_stack();
+#endif
+ wake_up_interruptible(&say_event);
+out_return:;
+}
+EXPORT_SYMBOL_GPL(brick_say_to);
+
+static
+void try_open_file(struct file **file, char *filename, bool creat)
+{
+ struct address_space *mapping;
+ int flags = O_APPEND | O_WRONLY | O_LARGEFILE;
+ int prot = 0600;
+
+ if (creat)
+ flags |= O_CREAT;
+
+ *file = filp_open(filename, flags, prot);
+ if (unlikely(IS_ERR(*file))) {
+ *file = NULL;
+ goto out_return;
+ }
+ mapping = (*file)->f_mapping;
+ if (likely(mapping))
+ mapping_set_gfp_mask(mapping, mapping_gfp_mask(mapping) & ~(__GFP_IO | __GFP_FS));
+out_return:;
+}
+
+static
+void out_to_file(struct file *file, char *buf, int len)
+{
+ loff_t log_pos = 0;
+
+ mm_segment_t oldfs;
+
+ if (file) {
+ oldfs = get_fs();
+ set_fs(get_ds());
+ (void)vfs_write(file, buf, len, &log_pos);
+ set_fs(oldfs);
+ }
+}
+
+static inline
+void reset_flood(void)
+{
+ if (flood_start_jiffies &&
+ time_is_before_jiffies(flood_start_jiffies + brick_say_syslog_flood_recovery * HZ)) {
+ flood_start_jiffies = 0;
+ flood_count = 0;
+ }
+}
+
+/* checkpatch.pl PREFER_PR_LEVEL:
+ *
+ * This is intended as _the_ _one_ subsystem-specific place where
+ * subsystem-specific {BRICK, MARS}_{INF, WRN, ERR, ...}() functions are
+ * mapped to the ordinary kernel printk().
+ *
+ * As noted elsewhere, dev_info() and friends connot be used in XIO_Light,
+ * because /dev/mars/ devices are created dynamically at runtime.
+ * On secondaries, no /dev/mars/ devices may exist at all.
+ *
+ * In case you want different naming conventions such als
+ * brick_err_printk() or similar, this could be automatically converted
+ * via the ./rework-mars-for-upstream.pl script.
+ * IMHO, the current naming conventions are short, systematic, and
+ * intuitive, so I personally would keep them in their current form.
+ */
+static
+void printk_with_class(int class, char *buf)
+{
+ switch (class) {
+ case SAY_INFO:
+ printk(KERN_INFO "%s", buf);
+ break;
+ case SAY_WARN:
+ printk(KERN_WARNING "%s", buf);
+ break;
+ case SAY_ERROR:
+ case SAY_FATAL:
+ printk(KERN_ERR "%s", buf);
+ break;
+ default:
+ printk(KERN_DEBUG "%s", buf);
+ }
+}
+
+static
+void out_to_syslog(int class, char *buf, int len)
+{
+ reset_flood();
+ if (class >= brick_say_syslog_min && class <= brick_say_syslog_max) {
+ buf[len] = '\0';
+ printk_with_class(class, buf);
+ } else if (class >= brick_say_syslog_flood_class && brick_say_syslog_flood_class >= 0 && class != SAY_TOTAL) {
+ flood_start_jiffies = jiffies;
+ if (++flood_count <= brick_say_syslog_flood_limit) {
+ buf[len] = '\0';
+ printk_with_class(class, buf);
+ }
+ }
+}
+
+static inline
+char *_make_filename(struct say_channel *ch, int class, int transact, int add_tmp)
+{
+ char *filename;
+
+restart:
+ filename = kmalloc(1024, GFP_KERNEL);
+ if (unlikely(!filename)) {
+ schedule();
+ goto restart;
+ }
+ atomic_inc(&say_alloc_names);
+ if (ch->ch_is_dir) {
+ snprintf(filename,
+ 1023,
+ "%s/%d.%s.%s%s",
+ ch->ch_name,
+ class,
+ say_class[class],
+ transact ? "status" : "log",
+ add_tmp ? ".tmp" : "");
+ } else {
+ snprintf(filename, 1023, "%s.%s%s", ch->ch_name, transact ? "status" : "log", add_tmp ? ".tmp" : "");
+ }
+ return filename;
+}
+
+static
+void _rollover_channel(struct say_channel *ch)
+{
+ int start = 0;
+ int class;
+
+ ch->ch_rollover = false;
+ ch->ch_status_written = 0;
+
+ if (!ch->ch_is_dir)
+ start = SAY_TOTAL;
+
+ for (class = start; class < MAX_SAY_CLASS; class++) {
+ char *old = _make_filename(ch, class, 1, 1);
+ char *new = _make_filename(ch, class, 1, 0);
+
+ if (likely(old && new)) {
+ int i;
+
+ mm_segment_t oldfs;
+
+ for (i = 0; i < 2; i++) {
+ if (ch->ch_filp[class][i]) {
+ filp_close(ch->ch_filp[class][i], NULL);
+ ch->ch_filp[class][i] = NULL;
+ }
+ }
+
+ oldfs = get_fs();
+ set_fs(get_ds());
+ sys_rename(old, new);
+ set_fs(oldfs);
+ }
+
+ if (likely(old)) {
+ kfree(old);
+ atomic_dec(&say_alloc_names);
+ }
+ if (likely(new)) {
+ kfree(new);
+ atomic_dec(&say_alloc_names);
+ }
+ }
+}
+
+static
+void treat_channel(struct say_channel *ch, int class)
+{
+ int len;
+ int overflow;
+ int transact;
+ int start;
+ char *buf;
+ char *tmp;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ch->ch_lock[class], flags);
+
+ buf = ch->ch_buf[class][0];
+ tmp = ch->ch_buf[class][1];
+ ch->ch_buf[class][1] = buf;
+ ch->ch_buf[class][0] = tmp;
+ len = ch->ch_index[class];
+ ch->ch_index[class] = 0;
+ overflow = ch->ch_overflow[class];
+ ch->ch_overflow[class] = 0;
+
+ spin_unlock_irqrestore(&ch->ch_lock[class], flags);
+
+ wake_up_interruptible(&ch->ch_progress);
+
+ ch->ch_status_written += len;
+ out_to_syslog(class, buf, len);
+ start = 0;
+ if (!brick_say_logging)
+ start++;
+ for (transact = start; transact < 2; transact++) {
+ if (unlikely(!ch->ch_filp[class][transact])) {
+ char *filename = _make_filename(ch, class, transact, transact);
+
+ if (likely(filename)) {
+ try_open_file(&ch->ch_filp[class][transact], filename, transact);
+ kfree(filename);
+ atomic_dec(&say_alloc_names);
+ }
+ }
+ out_to_file(ch->ch_filp[class][transact], buf, len);
+ }
+
+ if (unlikely(overflow > 0)) {
+ struct timespec s_now = CURRENT_TIME;
+ struct timespec l_now;
+
+ get_lamport(&l_now);
+ len = scnprintf(buf,
+ SAY_BUFMAX,
+ "%ld.%09ld %ld.%09ld %s %d OVERFLOW %d times\n",
+ s_now.tv_sec, s_now.tv_nsec,
+ l_now.tv_sec, l_now.tv_nsec,
+ ch->ch_name,
+ class,
+ overflow);
+ ch->ch_status_written += len;
+ out_to_syslog(class, buf, len);
+ for (transact = 0; transact < 2; transact++)
+ out_to_file(ch->ch_filp[class][transact], buf, len);
+ }
+}
+
+static
+int _say_thread(void *data)
+{
+ while (!kthread_should_stop()) {
+ struct say_channel *ch;
+ int i;
+
+ wait_event_interruptible_timeout(say_event, say_dirty, HZ);
+ say_dirty = false;
+
+restart_rollover:
+ read_lock(&say_lock);
+ for (ch = channel_list; ch; ch = ch->ch_next) {
+ if (ch->ch_rollover && ch->ch_status_written > 0) {
+ read_unlock(&say_lock);
+ _rollover_channel(ch);
+ goto restart_rollover;
+ }
+ }
+ read_unlock(&say_lock);
+
+restart:
+ read_lock(&say_lock);
+ for (ch = channel_list; ch; ch = ch->ch_next) {
+ int start = 0;
+
+ if (!ch->ch_is_dir)
+ start = SAY_TOTAL;
+ for (i = start; i < MAX_SAY_CLASS; i++) {
+ if (ch->ch_index[i] > 0) {
+ read_unlock(&say_lock);
+ treat_channel(ch, i);
+ goto restart;
+ }
+ }
+ if (ch->ch_delete) {
+ read_unlock(&say_lock);
+ _del_channel(ch);
+ goto restart;
+ }
+ }
+ read_unlock(&say_lock);
+ }
+
+ return 0;
+}
+
+void init_say(void)
+{
+ default_channel = make_channel(CONFIG_MARS_LOGDIR, true);
+ say_thread = kthread_create(_say_thread, NULL, "brick_say");
+ if (IS_ERR(say_thread)) {
+ say_thread = NULL;
+ } else {
+ get_task_struct(say_thread);
+ wake_up_process(say_thread);
+ }
+
+}
+EXPORT_SYMBOL_GPL(init_say);
+
+void exit_say(void)
+{
+ int memleak_channels;
+ int memleak_names;
+ int memleak_pages;
+
+ if (say_thread) {
+ kthread_stop(say_thread);
+ put_task_struct(say_thread);
+ say_thread = NULL;
+ }
+
+ default_channel = NULL;
+ while (channel_list)
+ _del_channel(channel_list);
+
+ memleak_channels = atomic_read(&say_alloc_channels);
+ memleak_names = atomic_read(&say_alloc_names);
+ memleak_pages = atomic_read(&say_alloc_pages);
+ if (unlikely(memleak_channels || memleak_names || memleak_pages))
+ printk("MEMLEAK: channels=%d names=%d pages=%d\n", memleak_channels, memleak_names, memleak_pages);
+}
+EXPORT_SYMBOL_GPL(exit_say);
+
+#ifdef CONFIG_MARS_DEBUG
+
+static int dump_max = 5;
+
+void brick_dump_stack(void)
+{
+ if (dump_max > 0) {
+ dump_max--; /* racy, but does no harm */
+ dump_stack();
+ }
+}
+EXPORT_SYMBOL(brick_dump_stack);
+
+#endif
--
2.0.0