[PATCH] pktcdvd: add sysfs and debugfs interface

Add a sysfs and debugfs interface to the pktcdvd driver.

Look into the Documentation/ABI/testing/* files in the patch for more info.

Signed-off-by: Thomas Maier <balagi@justmail.de>
Signed-off-by: Peter Osterlund <petero2@telia.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 439 insertions, 4 deletions

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 91fbe7fd6d0b..7c95c762950f 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -60,6 +60,8 @@
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_ioctl.h>
 #include <scsi/scsi.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
 
 #include <asm/uaccess.h>
 
@@ -89,6 +91,419 @@ static int write_congestion_off = PKT_WRITE_CONGESTION_OFF;
 static struct mutex ctl_mutex;  /* Serialize open/close/setup/teardown */
 static mempool_t *psd_pool;
 
+static struct class     *class_pktcdvd = NULL;    /* /sys/class/pktcdvd */
+static struct dentry    *pkt_debugfs_root = NULL; /* /debug/pktcdvd */
+
+/* forward declaration */
+static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev);
+static int pkt_remove_dev(dev_t pkt_dev);
+static int pkt_seq_show(struct seq_file *m, void *p);
+
+
+
+/*
+ * create and register a pktcdvd kernel object.
+ */
+static struct pktcdvd_kobj* pkt_kobj_create(struct pktcdvd_device *pd,
+                                        const char* name,
+                                        struct kobject* parent,
+                                        struct kobj_type* ktype)
+{
+        struct pktcdvd_kobj *p;
+        p = kzalloc(sizeof(*p), GFP_KERNEL);
+        if (!p)
+                return NULL;
+        kobject_set_name(&p->kobj, "%s", name);
+        p->kobj.parent = parent;
+        p->kobj.ktype = ktype;
+        p->pd = pd;
+        if (kobject_register(&p->kobj) != 0)
+                return NULL;
+        return p;
+}
+/*
+ * remove a pktcdvd kernel object.
+ */
+static void pkt_kobj_remove(struct pktcdvd_kobj *p)
+{
+        if (p)
+                kobject_unregister(&p->kobj);
+}
+/*
+ * default release function for pktcdvd kernel objects.
+ */
+static void pkt_kobj_release(struct kobject *kobj)
+{
+        kfree(to_pktcdvdkobj(kobj));
+}
+
+
+/**********************************************************
+ *
+ * sysfs interface for pktcdvd
+ * by (C) 2006  Thomas Maier <balagi@justmail.de>
+ *
+ **********************************************************/
+
+#define DEF_ATTR(_obj,_name,_mode) \
+        static struct attribute _obj = { \
+                .name = _name, .owner = THIS_MODULE, .mode = _mode }
+
+/**********************************************************
+  /sys/class/pktcdvd/pktcdvd[0-7]/
+                     stat/reset
+                     stat/packets_started
+                     stat/packets_finished
+                     stat/kb_written
+                     stat/kb_read
+                     stat/kb_read_gather
+                     write_queue/size
+                     write_queue/congestion_off
+                     write_queue/congestion_on
+ **********************************************************/
+
+DEF_ATTR(kobj_pkt_attr_st1, "reset", 0200);
+DEF_ATTR(kobj_pkt_attr_st2, "packets_started", 0444);
+DEF_ATTR(kobj_pkt_attr_st3, "packets_finished", 0444);
+DEF_ATTR(kobj_pkt_attr_st4, "kb_written", 0444);
+DEF_ATTR(kobj_pkt_attr_st5, "kb_read", 0444);
+DEF_ATTR(kobj_pkt_attr_st6, "kb_read_gather", 0444);
+
+static struct attribute *kobj_pkt_attrs_stat[] = {
+        &kobj_pkt_attr_st1,
+        &kobj_pkt_attr_st2,
+        &kobj_pkt_attr_st3,
+        &kobj_pkt_attr_st4,
+        &kobj_pkt_attr_st5,
+        &kobj_pkt_attr_st6,
+        NULL
+};
+
+DEF_ATTR(kobj_pkt_attr_wq1, "size", 0444);
+DEF_ATTR(kobj_pkt_attr_wq2, "congestion_off", 0644);
+DEF_ATTR(kobj_pkt_attr_wq3, "congestion_on",  0644);
+
+static struct attribute *kobj_pkt_attrs_wqueue[] = {
+        &kobj_pkt_attr_wq1,
+        &kobj_pkt_attr_wq2,
+        &kobj_pkt_attr_wq3,
+        NULL
+};
+
+/* declares a char buffer[64] _dbuf, copies data from
+ * _b with length _l into it and ensures that _dbuf ends
+ * with a \0 character.
+ */
+#define DECLARE_BUF_AS_STRING(_dbuf, _b, _l) \
+        char _dbuf[64]; int dlen = (_l) < 0 ? 0 : (_l); \
+        if (dlen >= sizeof(_dbuf)) dlen = sizeof(_dbuf)-1; \
+        memcpy(_dbuf, _b, dlen); _dbuf[dlen] = 0
+
+static ssize_t kobj_pkt_show(struct kobject *kobj,
+                        struct attribute *attr, char *data)
+{
+        struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
+        int n = 0;
+        int v;
+        if (strcmp(attr->name, "packets_started") == 0) {
+                n = sprintf(data, "%lu\n", pd->stats.pkt_started);
+
+        } else if (strcmp(attr->name, "packets_finished") == 0) {
+                n = sprintf(data, "%lu\n", pd->stats.pkt_ended);
+
+        } else if (strcmp(attr->name, "kb_written") == 0) {
+                n = sprintf(data, "%lu\n", pd->stats.secs_w >> 1);
+
+        } else if (strcmp(attr->name, "kb_read") == 0) {
+                n = sprintf(data, "%lu\n", pd->stats.secs_r >> 1);
+
+        } else if (strcmp(attr->name, "kb_read_gather") == 0) {
+                n = sprintf(data, "%lu\n", pd->stats.secs_rg >> 1);
+
+        } else if (strcmp(attr->name, "size") == 0) {
+                spin_lock(&pd->lock);
+                v = pd->bio_queue_size;
+                spin_unlock(&pd->lock);
+                n = sprintf(data, "%d\n", v);
+
+        } else if (strcmp(attr->name, "congestion_off") == 0) {
+                spin_lock(&pd->lock);
+                v = pd->write_congestion_off;
+                spin_unlock(&pd->lock);
+                n = sprintf(data, "%d\n", v);
+
+        } else if (strcmp(attr->name, "congestion_on") == 0) {
+                spin_lock(&pd->lock);
+                v = pd->write_congestion_on;
+                spin_unlock(&pd->lock);
+                n = sprintf(data, "%d\n", v);
+        }
+        return n;
+}
+
+static void init_write_congestion_marks(int* lo, int* hi)
+{
+        if (*hi > 0) {
+                *hi = max(*hi, 500);
+                *hi = min(*hi, 1000000);
+                if (*lo <= 0)
+                        *lo = *hi - 100;
+                else {
+                        *lo = min(*lo, *hi - 100);
+                        *lo = max(*lo, 100);
+                }
+        } else {
+                *hi = -1;
+                *lo = -1;
+        }
+}
+
+static ssize_t kobj_pkt_store(struct kobject *kobj,
+                        struct attribute *attr,
+                        const char *data, size_t len)
+{
+        struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
+        int val;
+        DECLARE_BUF_AS_STRING(dbuf, data, len); /* ensure sscanf scans a string */
+
+        if (strcmp(attr->name, "reset") == 0 && dlen > 0) {
+                pd->stats.pkt_started = 0;
+                pd->stats.pkt_ended = 0;
+                pd->stats.secs_w = 0;
+                pd->stats.secs_rg = 0;
+                pd->stats.secs_r = 0;
+
+        } else if (strcmp(attr->name, "congestion_off") == 0
+                   && sscanf(dbuf, "%d", &val) == 1) {
+                spin_lock(&pd->lock);
+                pd->write_congestion_off = val;
+                init_write_congestion_marks(&pd->write_congestion_off,
+                                        &pd->write_congestion_on);
+                spin_unlock(&pd->lock);
+
+        } else if (strcmp(attr->name, "congestion_on") == 0
+                   && sscanf(dbuf, "%d", &val) == 1) {
+                spin_lock(&pd->lock);
+                pd->write_congestion_on = val;
+                init_write_congestion_marks(&pd->write_congestion_off,
+                                        &pd->write_congestion_on);
+                spin_unlock(&pd->lock);
+        }
+        return len;
+}
+
+static struct sysfs_ops kobj_pkt_ops = {
+        .show = kobj_pkt_show,
+        .store = kobj_pkt_store
+};
+static struct kobj_type kobj_pkt_type_stat = {
+        .release = pkt_kobj_release,
+        .sysfs_ops = &kobj_pkt_ops,
+        .default_attrs = kobj_pkt_attrs_stat
+};
+static struct kobj_type kobj_pkt_type_wqueue = {
+        .release = pkt_kobj_release,
+        .sysfs_ops = &kobj_pkt_ops,
+        .default_attrs = kobj_pkt_attrs_wqueue
+};
+
+static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
+{
+        if (class_pktcdvd) {
+                pd->clsdev = class_device_create(class_pktcdvd,
+                                        NULL, pd->pkt_dev,
+                                        NULL, "%s", pd->name);
+                if (IS_ERR(pd->clsdev))
+                        pd->clsdev = NULL;
+        }
+        if (pd->clsdev) {
+                pd->kobj_stat = pkt_kobj_create(pd, "stat",
+                                        &pd->clsdev->kobj,
+                                        &kobj_pkt_type_stat);
+                pd->kobj_wqueue = pkt_kobj_create(pd, "write_queue",
+                                        &pd->clsdev->kobj,
+                                        &kobj_pkt_type_wqueue);
+        }
+}
+
+static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
+{
+        pkt_kobj_remove(pd->kobj_stat);
+        pkt_kobj_remove(pd->kobj_wqueue);
+        if (class_pktcdvd)
+                class_device_destroy(class_pktcdvd, pd->pkt_dev);
+}
+
+
+/********************************************************************
+  /sys/class/pktcdvd/
+                     add            map block device
+                     remove         unmap packet dev
+                     device_map     show mappings
+ *******************************************************************/
+
+static void class_pktcdvd_release(struct class *cls)
+{
+        kfree(cls);
+}
+static ssize_t class_pktcdvd_show_map(struct class *c, char *data)
+{
+        int n = 0;
+        int idx;
+        mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
+        for (idx = 0; idx < MAX_WRITERS; idx++) {
+                struct pktcdvd_device *pd = pkt_devs[idx];
+                if (!pd)
+                        continue;
+                n += sprintf(data+n, "%s %u:%u %u:%u\n",
+                        pd->name,
+                        MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
+                        MAJOR(pd->bdev->bd_dev),
+                        MINOR(pd->bdev->bd_dev));
+        }
+        mutex_unlock(&ctl_mutex);
+        return n;
+}
+
+static ssize_t class_pktcdvd_store_add(struct class *c, const char *buf,
+                                        size_t count)
+{
+        unsigned int major, minor;
+        DECLARE_BUF_AS_STRING(dbuf, buf, count);
+        if (sscanf(dbuf, "%u:%u", &major, &minor) == 2) {
+                pkt_setup_dev(MKDEV(major, minor), NULL);
+                return count;
+        }
+        return -EINVAL;
+}
+
+static ssize_t class_pktcdvd_store_remove(struct class *c, const char *buf,
+                                        size_t count)
+{
+        unsigned int major, minor;
+        DECLARE_BUF_AS_STRING(dbuf, buf, count);
+        if (sscanf(dbuf, "%u:%u", &major, &minor) == 2) {
+                pkt_remove_dev(MKDEV(major, minor));
+                return count;
+        }
+        return -EINVAL;
+}
+
+static struct class_attribute class_pktcdvd_attrs[] = {
+ __ATTR(add,            0200, NULL, class_pktcdvd_store_add),
+ __ATTR(remove,         0200, NULL, class_pktcdvd_store_remove),
+ __ATTR(device_map,     0444, class_pktcdvd_show_map, NULL),
+ __ATTR_NULL
+};
+
+
+static int pkt_sysfs_init(void)
+{
+        int ret = 0;
+
+        /*
+         * create control files in sysfs
+         * /sys/class/pktcdvd/...
+         */
+        class_pktcdvd = kzalloc(sizeof(*class_pktcdvd), GFP_KERNEL);
+        if (!class_pktcdvd)
+                return -ENOMEM;
+        class_pktcdvd->name = DRIVER_NAME;
+        class_pktcdvd->owner = THIS_MODULE;
+        class_pktcdvd->class_release = class_pktcdvd_release;
+        class_pktcdvd->class_attrs = class_pktcdvd_attrs;
+        ret = class_register(class_pktcdvd);
+        if (ret) {
+                kfree(class_pktcdvd);
+                class_pktcdvd = NULL;
+                printk(DRIVER_NAME": failed to create class pktcdvd\n");
+                return ret;
+        }
+        return 0;
+}
+
+static void pkt_sysfs_cleanup(void)
+{
+        if (class_pktcdvd)
+                class_destroy(class_pktcdvd);
+        class_pktcdvd = NULL;
+}
+
+/********************************************************************
+  entries in debugfs
+
+  /debugfs/pktcdvd[0-7]/
+                        info
+
+ *******************************************************************/
+
+static int pkt_debugfs_seq_show(struct seq_file *m, void *p)
+{
+        return pkt_seq_show(m, p);
+}
+
+static int pkt_debugfs_fops_open(struct inode *inode, struct file *file)
+{
+        return single_open(file, pkt_debugfs_seq_show, inode->i_private);
+}
+
+static struct file_operations debug_fops = {
+        .open           = pkt_debugfs_fops_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = single_release,
+        .owner          = THIS_MODULE,
+};
+
+static void pkt_debugfs_dev_new(struct pktcdvd_device *pd)
+{
+        if (!pkt_debugfs_root)
+                return;
+        pd->dfs_f_info = NULL;
+        pd->dfs_d_root = debugfs_create_dir(pd->name, pkt_debugfs_root);
+        if (IS_ERR(pd->dfs_d_root)) {
+                pd->dfs_d_root = NULL;
+                return;
+        }
+        pd->dfs_f_info = debugfs_create_file("info", S_IRUGO,
+                                pd->dfs_d_root, pd, &debug_fops);
+        if (IS_ERR(pd->dfs_f_info)) {
+                pd->dfs_f_info = NULL;
+                return;
+        }
+}
+
+static void pkt_debugfs_dev_remove(struct pktcdvd_device *pd)
+{
+        if (!pkt_debugfs_root)
+                return;
+        if (pd->dfs_f_info)
+                debugfs_remove(pd->dfs_f_info);
+        pd->dfs_f_info = NULL;
+        if (pd->dfs_d_root)
+                debugfs_remove(pd->dfs_d_root);
+        pd->dfs_d_root = NULL;
+}
+
+static void pkt_debugfs_init(void)
+{
+        pkt_debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
+        if (IS_ERR(pkt_debugfs_root)) {
+                pkt_debugfs_root = NULL;
+                return;
+        }
+}
+
+static void pkt_debugfs_cleanup(void)
+{
+        if (!pkt_debugfs_root)
+                return;
+        debugfs_remove(pkt_debugfs_root);
+        pkt_debugfs_root = NULL;
+}
+
+/* ----------------------------------------------------------*/
+
 
 static void pkt_bio_finished(struct pktcdvd_device *pd)
 {
@@ -2527,6 +2942,9 @@ static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
 
         add_disk(disk);
 
+        pkt_sysfs_dev_new(pd);
+        pkt_debugfs_dev_new(pd);
+
         pkt_devs[idx] = pd;
         if (pkt_dev)
                 *pkt_dev = pd->pkt_dev;
@@ -2577,6 +2995,11 @@ static int pkt_remove_dev(dev_t pkt_dev)
         if (!IS_ERR(pd->cdrw.thread))
                 kthread_stop(pd->cdrw.thread);
 
+        pkt_devs[idx] = NULL;
+
+        pkt_debugfs_dev_remove(pd);
+        pkt_sysfs_dev_remove(pd);
+
         blkdev_put(pd->bdev);
 
         remove_proc_entry(pd->name, pkt_proc);
@@ -2586,7 +3009,6 @@ static int pkt_remove_dev(dev_t pkt_dev)
         blk_cleanup_queue(pd->disk->queue);
         put_disk(pd->disk);
 
-        pkt_devs[idx] = NULL;
         mempool_destroy(pd->rb_pool);
         kfree(pd);
 
@@ -2670,6 +3092,8 @@ static int __init pkt_init(void)
 {
         int ret;
 
+        mutex_init(&ctl_mutex);
+
         psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
                                         sizeof(struct packet_stacked_data));
         if (!psd_pool)
@@ -2683,18 +3107,25 @@ static int __init pkt_init(void)
         if (!pktdev_major)
                 pktdev_major = ret;
 
+        ret = pkt_sysfs_init();
+        if (ret)
+                goto out;
+
+        pkt_debugfs_init();
+
         ret = misc_register(&pkt_misc);
         if (ret) {
                 printk(DRIVER_NAME": Unable to register misc device\n");
-                goto out;
+                goto out_misc;
         }
 
-        mutex_init(&ctl_mutex);
-
         pkt_proc = proc_mkdir(DRIVER_NAME, proc_root_driver);
 
         return 0;
 
+out_misc:
+        pkt_debugfs_cleanup();
+        pkt_sysfs_cleanup();
 out:
         unregister_blkdev(pktdev_major, DRIVER_NAME);
 out2:
@@ -2706,6 +3137,10 @@ static void __exit pkt_exit(void)
 {
         remove_proc_entry(DRIVER_NAME, proc_root_driver);
         misc_deregister(&pkt_misc);
+
+        pkt_debugfs_cleanup();
+        pkt_sysfs_cleanup();
+
         unregister_blkdev(pktdev_major, DRIVER_NAME);
         mempool_destroy(psd_pool);
 }