This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / block / genhd.c
diff --git a/block/genhd.c b/block/genhd.c
new file mode 100644 (file)
index 0000000..5a8d3bf
--- /dev/null
@@ -0,0 +1,714 @@
+/*
+ *  gendisk handling
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/genhd.h>
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/kmod.h>
+#include <linux/kobj_map.h>
+#include <linux/buffer_head.h>
+#include <linux/mutex.h>
+
+static struct subsystem block_subsys;
+
+static DEFINE_MUTEX(block_subsys_lock);
+
+/*
+ * Can be deleted altogether. Later.
+ *
+ */
+static struct blk_major_name {
+       struct blk_major_name *next;
+       int major;
+       char name[16];
+} *major_names[BLKDEV_MAJOR_HASH_SIZE];
+
+/* index in the above - for now: assume no multimajor ranges */
+static inline int major_to_index(int major)
+{
+       return major % BLKDEV_MAJOR_HASH_SIZE;
+}
+
+#ifdef CONFIG_PROC_FS
+
+void blkdev_show(struct seq_file *f, off_t offset)
+{
+       struct blk_major_name *dp;
+
+       if (offset < BLKDEV_MAJOR_HASH_SIZE) {
+               mutex_lock(&block_subsys_lock);
+               for (dp = major_names[offset]; dp; dp = dp->next)
+                       seq_printf(f, "%3d %s\n", dp->major, dp->name);
+               mutex_unlock(&block_subsys_lock);
+       }
+}
+
+#endif /* CONFIG_PROC_FS */
+
+int register_blkdev(unsigned int major, const char *name)
+{
+       struct blk_major_name **n, *p;
+       int index, ret = 0;
+
+       mutex_lock(&block_subsys_lock);
+
+       /* temporary */
+       if (major == 0) {
+               for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
+                       if (major_names[index] == NULL)
+                               break;
+               }
+
+               if (index == 0) {
+                       printk("register_blkdev: failed to get major for %s\n",
+                              name);
+                       ret = -EBUSY;
+                       goto out;
+               }
+               major = index;
+               ret = major;
+       }
+
+       p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
+       if (p == NULL) {
+               ret = -ENOMEM;
+               goto out;
+       }
+
+       p->major = major;
+       strlcpy(p->name, name, sizeof(p->name));
+       p->next = NULL;
+       index = major_to_index(major);
+
+       for (n = &major_names[index]; *n; n = &(*n)->next) {
+               if ((*n)->major == major)
+                       break;
+       }
+       if (!*n)
+               *n = p;
+       else
+               ret = -EBUSY;
+
+       if (ret < 0) {
+               printk("register_blkdev: cannot get major %d for %s\n",
+                      major, name);
+               kfree(p);
+       }
+out:
+       mutex_unlock(&block_subsys_lock);
+       return ret;
+}
+
+EXPORT_SYMBOL(register_blkdev);
+
+/* todo: make void - error printk here */
+int unregister_blkdev(unsigned int major, const char *name)
+{
+       struct blk_major_name **n;
+       struct blk_major_name *p = NULL;
+       int index = major_to_index(major);
+       int ret = 0;
+
+       mutex_lock(&block_subsys_lock);
+       for (n = &major_names[index]; *n; n = &(*n)->next)
+               if ((*n)->major == major)
+                       break;
+       if (!*n || strcmp((*n)->name, name))
+               ret = -EINVAL;
+       else {
+               p = *n;
+               *n = p->next;
+       }
+       mutex_unlock(&block_subsys_lock);
+       kfree(p);
+
+       return ret;
+}
+
+EXPORT_SYMBOL(unregister_blkdev);
+
+static struct kobj_map *bdev_map;
+
+/*
+ * Register device numbers dev..(dev+range-1)
+ * range must be nonzero
+ * The hash chain is sorted on range, so that subranges can override.
+ */
+void blk_register_region(dev_t dev, unsigned long range, struct module *module,
+                        struct kobject *(*probe)(dev_t, int *, void *),
+                        int (*lock)(dev_t, void *), void *data)
+{
+       kobj_map(bdev_map, dev, range, module, probe, lock, data);
+}
+
+EXPORT_SYMBOL(blk_register_region);
+
+void blk_unregister_region(dev_t dev, unsigned long range)
+{
+       kobj_unmap(bdev_map, dev, range);
+}
+
+EXPORT_SYMBOL(blk_unregister_region);
+
+static struct kobject *exact_match(dev_t dev, int *part, void *data)
+{
+       struct gendisk *p = data;
+       return &p->kobj;
+}
+
+static int exact_lock(dev_t dev, void *data)
+{
+       struct gendisk *p = data;
+
+       if (!get_disk(p))
+               return -1;
+       return 0;
+}
+
+/**
+ * add_disk - add partitioning information to kernel list
+ * @disk: per-device partitioning information
+ *
+ * This function registers the partitioning information in @disk
+ * with the kernel.
+ */
+void add_disk(struct gendisk *disk)
+{
+       disk->flags |= GENHD_FL_UP;
+       blk_register_region(MKDEV(disk->major, disk->first_minor),
+                           disk->minors, NULL, exact_match, exact_lock, disk);
+       register_disk(disk);
+       blk_register_queue(disk);
+}
+
+EXPORT_SYMBOL(add_disk);
+EXPORT_SYMBOL(del_gendisk);    /* in partitions/check.c */
+
+void unlink_gendisk(struct gendisk *disk)
+{
+       blk_unregister_queue(disk);
+       blk_unregister_region(MKDEV(disk->major, disk->first_minor),
+                             disk->minors);
+}
+
+#define to_disk(obj) container_of(obj,struct gendisk,kobj)
+
+/**
+ * get_gendisk - get partitioning information for a given device
+ * @dev: device to get partitioning information for
+ *
+ * This function gets the structure containing partitioning
+ * information for the given device @dev.
+ */
+struct gendisk *get_gendisk(dev_t dev, int *part)
+{
+       struct kobject *kobj = kobj_lookup(bdev_map, dev, part);
+       return  kobj ? to_disk(kobj) : NULL;
+}
+
+#ifdef CONFIG_PROC_FS
+/* iterator */
+static void *part_start(struct seq_file *part, loff_t *pos)
+{
+       struct list_head *p;
+       loff_t l = *pos;
+
+       mutex_lock(&block_subsys_lock);
+       list_for_each(p, &block_subsys.kset.list)
+               if (!l--)
+                       return list_entry(p, struct gendisk, kobj.entry);
+       return NULL;
+}
+
+static void *part_next(struct seq_file *part, void *v, loff_t *pos)
+{
+       struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
+       ++*pos;
+       return p==&block_subsys.kset.list ? NULL : 
+               list_entry(p, struct gendisk, kobj.entry);
+}
+
+static void part_stop(struct seq_file *part, void *v)
+{
+       mutex_unlock(&block_subsys_lock);
+}
+
+static int show_partition(struct seq_file *part, void *v)
+{
+       struct gendisk *sgp = v;
+       int n;
+       char buf[BDEVNAME_SIZE];
+
+       if (&sgp->kobj.entry == block_subsys.kset.list.next)
+               seq_puts(part, "major minor  #blocks  name\n\n");
+
+       /* Don't show non-partitionable removeable devices or empty devices */
+       if (!get_capacity(sgp) ||
+                       (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
+               return 0;
+       if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
+               return 0;
+
+       /* show the full disk and all non-0 size partitions of it */
+       seq_printf(part, "%4d  %4d %10llu %s\n",
+               sgp->major, sgp->first_minor,
+               (unsigned long long)get_capacity(sgp) >> 1,
+               disk_name(sgp, 0, buf));
+       for (n = 0; n < sgp->minors - 1; n++) {
+               if (!sgp->part[n])
+                       continue;
+               if (sgp->part[n]->nr_sects == 0)
+                       continue;
+               seq_printf(part, "%4d  %4d %10llu %s\n",
+                       sgp->major, n + 1 + sgp->first_minor,
+                       (unsigned long long)sgp->part[n]->nr_sects >> 1 ,
+                       disk_name(sgp, n + 1, buf));
+       }
+
+       return 0;
+}
+
+struct seq_operations partitions_op = {
+       .start =part_start,
+       .next = part_next,
+       .stop = part_stop,
+       .show = show_partition
+};
+#endif
+
+
+extern int blk_dev_init(void);
+
+static struct kobject *base_probe(dev_t dev, int *part, void *data)
+{
+       if (request_module("block-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0)
+               /* Make old-style 2.4 aliases work */
+               request_module("block-major-%d", MAJOR(dev));
+       return NULL;
+}
+
+static int __init genhd_device_init(void)
+{
+       bdev_map = kobj_map_init(base_probe, &block_subsys_lock);
+       blk_dev_init();
+       subsystem_register(&block_subsys);
+       return 0;
+}
+
+subsys_initcall(genhd_device_init);
+
+
+
+/*
+ * kobject & sysfs bindings for block devices
+ */
+static ssize_t disk_attr_show(struct kobject *kobj, struct attribute *attr,
+                             char *page)
+{
+       struct gendisk *disk = to_disk(kobj);
+       struct disk_attribute *disk_attr =
+               container_of(attr,struct disk_attribute,attr);
+       ssize_t ret = -EIO;
+
+       if (disk_attr->show)
+               ret = disk_attr->show(disk,page);
+       return ret;
+}
+
+static ssize_t disk_attr_store(struct kobject * kobj, struct attribute * attr,
+                              const char *page, size_t count)
+{
+       struct gendisk *disk = to_disk(kobj);
+       struct disk_attribute *disk_attr =
+               container_of(attr,struct disk_attribute,attr);
+       ssize_t ret = 0;
+
+       if (disk_attr->store)
+               ret = disk_attr->store(disk, page, count);
+       return ret;
+}
+
+static struct sysfs_ops disk_sysfs_ops = {
+       .show   = &disk_attr_show,
+       .store  = &disk_attr_store,
+};
+
+static ssize_t disk_uevent_store(struct gendisk * disk,
+                                const char *buf, size_t count)
+{
+       kobject_uevent(&disk->kobj, KOBJ_ADD);
+       return count;
+}
+static ssize_t disk_dev_read(struct gendisk * disk, char *page)
+{
+       dev_t base = MKDEV(disk->major, disk->first_minor); 
+       return print_dev_t(page, base);
+}
+static ssize_t disk_range_read(struct gendisk * disk, char *page)
+{
+       return sprintf(page, "%d\n", disk->minors);
+}
+static ssize_t disk_removable_read(struct gendisk * disk, char *page)
+{
+       return sprintf(page, "%d\n",
+                      (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
+
+}
+static ssize_t disk_size_read(struct gendisk * disk, char *page)
+{
+       return sprintf(page, "%llu\n", (unsigned long long)get_capacity(disk));
+}
+
+static ssize_t disk_stats_read(struct gendisk * disk, char *page)
+{
+       preempt_disable();
+       disk_round_stats(disk);
+       preempt_enable();
+       return sprintf(page,
+               "%8lu %8lu %8llu %8u "
+               "%8lu %8lu %8llu %8u "
+               "%8u %8u %8u"
+               "\n",
+               disk_stat_read(disk, ios[READ]),
+               disk_stat_read(disk, merges[READ]),
+               (unsigned long long)disk_stat_read(disk, sectors[READ]),
+               jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
+               disk_stat_read(disk, ios[WRITE]),
+               disk_stat_read(disk, merges[WRITE]),
+               (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
+               jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
+               disk->in_flight,
+               jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
+               jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
+}
+static struct disk_attribute disk_attr_uevent = {
+       .attr = {.name = "uevent", .mode = S_IWUSR },
+       .store  = disk_uevent_store
+};
+static struct disk_attribute disk_attr_dev = {
+       .attr = {.name = "dev", .mode = S_IRUGO },
+       .show   = disk_dev_read
+};
+static struct disk_attribute disk_attr_range = {
+       .attr = {.name = "range", .mode = S_IRUGO },
+       .show   = disk_range_read
+};
+static struct disk_attribute disk_attr_removable = {
+       .attr = {.name = "removable", .mode = S_IRUGO },
+       .show   = disk_removable_read
+};
+static struct disk_attribute disk_attr_size = {
+       .attr = {.name = "size", .mode = S_IRUGO },
+       .show   = disk_size_read
+};
+static struct disk_attribute disk_attr_stat = {
+       .attr = {.name = "stat", .mode = S_IRUGO },
+       .show   = disk_stats_read
+};
+
+static struct attribute * default_attrs[] = {
+       &disk_attr_uevent.attr,
+       &disk_attr_dev.attr,
+       &disk_attr_range.attr,
+       &disk_attr_removable.attr,
+       &disk_attr_size.attr,
+       &disk_attr_stat.attr,
+       NULL,
+};
+
+static void disk_release(struct kobject * kobj)
+{
+       struct gendisk *disk = to_disk(kobj);
+       kfree(disk->random);
+       kfree(disk->part);
+       free_disk_stats(disk);
+       kfree(disk);
+}
+
+static struct kobj_type ktype_block = {
+       .release        = disk_release,
+       .sysfs_ops      = &disk_sysfs_ops,
+       .default_attrs  = default_attrs,
+};
+
+extern struct kobj_type ktype_part;
+
+static int block_uevent_filter(struct kset *kset, struct kobject *kobj)
+{
+       struct kobj_type *ktype = get_ktype(kobj);
+
+       return ((ktype == &ktype_block) || (ktype == &ktype_part));
+}
+
+static int block_uevent(struct kset *kset, struct kobject *kobj, char **envp,
+                        int num_envp, char *buffer, int buffer_size)
+{
+       struct kobj_type *ktype = get_ktype(kobj);
+       struct device *physdev;
+       struct gendisk *disk;
+       struct hd_struct *part;
+       int length = 0;
+       int i = 0;
+
+       if (ktype == &ktype_block) {
+               disk = container_of(kobj, struct gendisk, kobj);
+               add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
+                              &length, "MINOR=%u", disk->first_minor);
+       } else if (ktype == &ktype_part) {
+               disk = container_of(kobj->parent, struct gendisk, kobj);
+               part = container_of(kobj, struct hd_struct, kobj);
+               add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
+                              &length, "MINOR=%u",
+                              disk->first_minor + part->partno);
+       } else
+               return 0;
+
+       add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
+                      "MAJOR=%u", disk->major);
+
+       /* add physical device, backing this device  */
+       physdev = disk->driverfs_dev;
+       if (physdev) {
+               char *path = kobject_get_path(&physdev->kobj, GFP_KERNEL);
+
+               add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
+                              &length, "PHYSDEVPATH=%s", path);
+               kfree(path);
+
+               if (physdev->bus)
+                       add_uevent_var(envp, num_envp, &i,
+                                      buffer, buffer_size, &length,
+                                      "PHYSDEVBUS=%s",
+                                      physdev->bus->name);
+
+               if (physdev->driver)
+                       add_uevent_var(envp, num_envp, &i,
+                                      buffer, buffer_size, &length,
+                                      "PHYSDEVDRIVER=%s",
+                                      physdev->driver->name);
+       }
+
+       /* terminate, set to next free slot, shrink available space */
+       envp[i] = NULL;
+       envp = &envp[i];
+       num_envp -= i;
+       buffer = &buffer[length];
+       buffer_size -= length;
+
+       return 0;
+}
+
+static struct kset_uevent_ops block_uevent_ops = {
+       .filter         = block_uevent_filter,
+       .uevent         = block_uevent,
+};
+
+/* declare block_subsys. */
+static decl_subsys(block, &ktype_block, &block_uevent_ops);
+
+
+/*
+ * aggregate disk stat collector.  Uses the same stats that the sysfs
+ * entries do, above, but makes them available through one seq_file.
+ * Watching a few disks may be efficient through sysfs, but watching
+ * all of them will be more efficient through this interface.
+ *
+ * The output looks suspiciously like /proc/partitions with a bunch of
+ * extra fields.
+ */
+
+/* iterator */
+static void *diskstats_start(struct seq_file *part, loff_t *pos)
+{
+       loff_t k = *pos;
+       struct list_head *p;
+
+       mutex_lock(&block_subsys_lock);
+       list_for_each(p, &block_subsys.kset.list)
+               if (!k--)
+                       return list_entry(p, struct gendisk, kobj.entry);
+       return NULL;
+}
+
+static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
+{
+       struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
+       ++*pos;
+       return p==&block_subsys.kset.list ? NULL :
+               list_entry(p, struct gendisk, kobj.entry);
+}
+
+static void diskstats_stop(struct seq_file *part, void *v)
+{
+       mutex_unlock(&block_subsys_lock);
+}
+
+static int diskstats_show(struct seq_file *s, void *v)
+{
+       struct gendisk *gp = v;
+       char buf[BDEVNAME_SIZE];
+       int n = 0;
+
+       /*
+       if (&sgp->kobj.entry == block_subsys.kset.list.next)
+               seq_puts(s,     "major minor name"
+                               "     rio rmerge rsect ruse wio wmerge "
+                               "wsect wuse running use aveq"
+                               "\n\n");
+       */
+       preempt_disable();
+       disk_round_stats(gp);
+       preempt_enable();
+       seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
+               gp->major, n + gp->first_minor, disk_name(gp, n, buf),
+               disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
+               (unsigned long long)disk_stat_read(gp, sectors[0]),
+               jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
+               disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
+               (unsigned long long)disk_stat_read(gp, sectors[1]),
+               jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
+               gp->in_flight,
+               jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
+               jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
+
+       /* now show all non-0 size partitions of it */
+       for (n = 0; n < gp->minors - 1; n++) {
+               struct hd_struct *hd = gp->part[n];
+
+               if (hd && hd->nr_sects)
+                       seq_printf(s, "%4d %4d %s %u %u %u %u\n",
+                               gp->major, n + gp->first_minor + 1,
+                               disk_name(gp, n + 1, buf),
+                               hd->ios[0], hd->sectors[0],
+                               hd->ios[1], hd->sectors[1]);
+       }
+       return 0;
+}
+
+struct seq_operations diskstats_op = {
+       .start  = diskstats_start,
+       .next   = diskstats_next,
+       .stop   = diskstats_stop,
+       .show   = diskstats_show
+};
+
+struct gendisk *alloc_disk(int minors)
+{
+       return alloc_disk_node(minors, -1);
+}
+
+struct gendisk *alloc_disk_node(int minors, int node_id)
+{
+       struct gendisk *disk;
+
+       disk = kmalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
+       if (disk) {
+               memset(disk, 0, sizeof(struct gendisk));
+               if (!init_disk_stats(disk)) {
+                       kfree(disk);
+                       return NULL;
+               }
+               if (minors > 1) {
+                       int size = (minors - 1) * sizeof(struct hd_struct *);
+                       disk->part = kmalloc_node(size, GFP_KERNEL, node_id);
+                       if (!disk->part) {
+                               kfree(disk);
+                               return NULL;
+                       }
+                       memset(disk->part, 0, size);
+               }
+               disk->minors = minors;
+               kobj_set_kset_s(disk,block_subsys);
+               kobject_init(&disk->kobj);
+               rand_initialize_disk(disk);
+       }
+       return disk;
+}
+
+EXPORT_SYMBOL(alloc_disk);
+EXPORT_SYMBOL(alloc_disk_node);
+
+struct kobject *get_disk(struct gendisk *disk)
+{
+       struct module *owner;
+       struct kobject *kobj;
+
+       if (!disk->fops)
+               return NULL;
+       owner = disk->fops->owner;
+       if (owner && !try_module_get(owner))
+               return NULL;
+       kobj = kobject_get(&disk->kobj);
+       if (kobj == NULL) {
+               module_put(owner);
+               return NULL;
+       }
+       return kobj;
+
+}
+
+EXPORT_SYMBOL(get_disk);
+
+void put_disk(struct gendisk *disk)
+{
+       if (disk)
+               kobject_put(&disk->kobj);
+}
+
+EXPORT_SYMBOL(put_disk);
+
+void set_device_ro(struct block_device *bdev, int flag)
+{
+       if (bdev->bd_contains != bdev)
+               bdev->bd_part->policy = flag;
+       else
+               bdev->bd_disk->policy = flag;
+}
+
+EXPORT_SYMBOL(set_device_ro);
+
+void set_disk_ro(struct gendisk *disk, int flag)
+{
+       int i;
+       disk->policy = flag;
+       for (i = 0; i < disk->minors - 1; i++)
+               if (disk->part[i]) disk->part[i]->policy = flag;
+}
+
+EXPORT_SYMBOL(set_disk_ro);
+
+int bdev_read_only(struct block_device *bdev)
+{
+       if (!bdev)
+               return 0;
+       else if (bdev->bd_contains != bdev)
+               return bdev->bd_part->policy;
+       else
+               return bdev->bd_disk->policy;
+}
+
+EXPORT_SYMBOL(bdev_read_only);
+
+int invalidate_partition(struct gendisk *disk, int index)
+{
+       int res = 0;
+       struct block_device *bdev = bdget_disk(disk, index);
+       if (bdev) {
+               fsync_bdev(bdev);
+               res = __invalidate_device(bdev);
+               bdput(bdev);
+       }
+       return res;
+}
+
+EXPORT_SYMBOL(invalidate_partition);