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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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SPDX-License-Identifier: GPL-2.0/* * gendisk handling * * Portions Copyright (C) 2020 Christoph Hellwig */
#include <linux/module.h>#include <linux/ctype.h>#include <linux/fs.h>#include <linux/kdev_t.h>#include <linux/kernel.h>#include <linux/blkdev.h>#include <linux/backing-dev.h>#include <linux/init.h>#include <linux/spinlock.h>#include <linux/proc_fs.h>#include <linux/seq_file.h>#include <linux/slab.h>#include <linux/kmod.h>#include <linux/major.h>#include <linux/mutex.h>#include <linux/idr.h>#include <linux/log2.h>#include <linux/pm_runtime.h>#include <linux/badblocks.h>#include <linux/part_stat.h>#include <linux/blktrace_api.h>
#include "blk-throttle.h"#include "blk.h"#include "blk-mq-sched.h"#include "blk-rq-qos.h"#include "blk-cgroup.h"
static struct kobject *block_depr;
/* * Unique, monotonically increasing sequential number associated with block * devices instances (i.e. incremented each time a device is attached). * Associating uevents with block devices in userspace is difficult and racy: * the uevent netlink socket is lossy, and on slow and overloaded systems has * a very high latency. * Block devices do not have exclusive owners in userspace, any process can set * one up (e.g. loop devices). Moreover, device names can be reused (e.g. loop0 * can be reused again and again). * A userspace process setting up a block device and watching for its events * cannot thus reliably tell whether an event relates to the device it just set * up or another earlier instance with the same name. * This sequential number allows userspace processes to solve this problem, and * uniquely associate an uevent to the lifetime to a device. */static atomic64_t diskseq;
/* for extended dynamic devt allocation, currently only one major is used */#define NR_EXT_DEVT (1 << MINORBITS)static DEFINE_IDA(ext_devt_ida);
void set_capacity(struct gendisk *disk, sector_t sectors){ if (sectors > BLK_DEV_MAX_SECTORS) { pr_warn_once("%s: truncate capacity from %lld to %lld\n", disk->disk_name, sectors, BLK_DEV_MAX_SECTORS); sectors = BLK_DEV_MAX_SECTORS; }
bdev_set_nr_sectors(disk->part0, sectors);}EXPORT_SYMBOL(set_capacity);
/* * Set disk capacity and notify if the size is not currently zero and will not * be set to zero. Returns true if a uevent was sent, otherwise false. */bool set_capacity_and_notify(struct gendisk *disk, sector_t size){ sector_t capacity = get_capacity(disk); char *envp[] = { "RESIZE=1", NULL };
set_capacity(disk, size);
/* * Only print a message and send a uevent if the gendisk is user visible * and alive. This avoids spamming the log and udev when setting the * initial capacity during probing. */ if (size == capacity || !disk_live(disk) || (disk->flags & GENHD_FL_HIDDEN)) return false;
pr_info_ratelimited("%s: detected capacity change from %lld to %lld\n", disk->disk_name, capacity, size);
/* * Historically we did not send a uevent for changes to/from an empty * device. */ if (!capacity || !size) return false; kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp); return true;}EXPORT_SYMBOL_GPL(set_capacity_and_notify);
static void part_stat_read_all(struct block_device *part, struct disk_stats *stat){ int cpu;
memset(stat, 0, sizeof(struct disk_stats)); for_each_possible_cpu(cpu) { struct disk_stats *ptr = per_cpu_ptr(part->bd_stats, cpu); int group;
for (group = 0; group < NR_STAT_GROUPS; group++) { stat->nsecs[group] += ptr->nsecs[group]; stat->sectors[group] += ptr->sectors[group]; stat->ios[group] += ptr->ios[group]; stat->merges[group] += ptr->merges[group]; }
stat->io_ticks += ptr->io_ticks; }}
static void bdev_count_inflight_rw(struct block_device *part, unsigned int inflight[2], bool mq_driver){ int write = 0; int read = 0; int cpu;
if (mq_driver) { blk_mq_in_driver_rw(part, inflight); return; }
for_each_possible_cpu(cpu) { read += part_stat_local_read_cpu(part, in_flight[READ], cpu); write += part_stat_local_read_cpu(part, in_flight[WRITE], cpu); }
/* * While iterating all CPUs, some IOs may be issued from a CPU already * traversed and complete on a CPU that has not yet been traversed, * causing the inflight number to be negative. */ inflight[READ] = read > 0 ? read : 0; inflight[WRITE] = write > 0 ? write : 0;}
/** * bdev_count_inflight - get the number of inflight IOs for a block device. * * @part: the block device. * * Inflight here means started IO accounting, from bdev_start_io_acct() for * bio-based block device, and from blk_account_io_start() for rq-based block * device. */unsigned int bdev_count_inflight(struct block_device *part){ unsigned int inflight[2] = {0};
bdev_count_inflight_rw(part, inflight, false);
return inflight[READ] + inflight[WRITE];}EXPORT_SYMBOL_GPL(bdev_count_inflight);
/* * Can be deleted altogether. Later. * */#define BLKDEV_MAJOR_HASH_SIZE 255static struct blk_major_name { struct blk_major_name *next; int major; char name[16];#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD void (*probe)(dev_t devt);#endif} *major_names[BLKDEV_MAJOR_HASH_SIZE];static DEFINE_MUTEX(major_names_lock);static DEFINE_SPINLOCK(major_names_spinlock);
/* index in the above - for now: assume no multimajor ranges */static inline int major_to_index(unsigned major){ return major % BLKDEV_MAJOR_HASH_SIZE;}
#ifdef CONFIG_PROC_FSvoid blkdev_show(struct seq_file *seqf, off_t offset){ struct blk_major_name *dp;
spin_lock(&major_names_spinlock); for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next) if (dp->major == offset) seq_printf(seqf, "%3d %s\n", dp->major, dp->name); spin_unlock(&major_names_spinlock);}#endif /* CONFIG_PROC_FS */
/** * __register_blkdev - register a new block device * * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If * @major = 0, try to allocate any unused major number. * @name: the name of the new block device as a zero terminated string * @probe: pre-devtmpfs / pre-udev callback used to create disks when their * pre-created device node is accessed. When a probe call uses * add_disk() and it fails the driver must cleanup resources. This * interface may soon be removed. * * The @name must be unique within the system. * * The return value depends on the @major input parameter: * * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1] * then the function returns zero on success, or a negative error code * - if any unused major number was requested with @major = 0 parameter * then the return value is the allocated major number in range * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise * * See Documentation/admin-guide/devices.txt for the list of allocated * major numbers. * * Use register_blkdev instead for any new code. */int __register_blkdev(unsigned int major, const char *name, void (*probe)(dev_t devt)){ struct blk_major_name **n, *p; int index, ret = 0;
mutex_lock(&major_names_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("%s: failed to get major for %s\n", __func__, name); ret = -EBUSY; goto out; } major = index; ret = major; }
if (major >= BLKDEV_MAJOR_MAX) { pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n", __func__, major, BLKDEV_MAJOR_MAX-1, name);
ret = -EINVAL; goto out; }
p = kmalloc_obj(struct blk_major_name); if (p == NULL) { ret = -ENOMEM; goto out; }
p->major = major;#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD p->probe = probe;#endif strscpy(p->name, name, sizeof(p->name)); p->next = NULL; index = major_to_index(major);
spin_lock(&major_names_spinlock); for (n = &major_names[index]; *n; n = &(*n)->next) { if ((*n)->major == major) break; } if (!*n) *n = p; else ret = -EBUSY; spin_unlock(&major_names_spinlock);
if (ret < 0) { printk("register_blkdev: cannot get major %u for %s\n", major, name); kfree(p); }out: mutex_unlock(&major_names_lock); return ret;}EXPORT_SYMBOL(__register_blkdev);
void 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);
mutex_lock(&major_names_lock); spin_lock(&major_names_spinlock); for (n = &major_names[index]; *n; n = &(*n)->next) if ((*n)->major == major) break; if (!*n || strcmp((*n)->name, name)) { WARN_ON(1); } else { p = *n; *n = p->next; } spin_unlock(&major_names_spinlock); mutex_unlock(&major_names_lock); kfree(p);}
EXPORT_SYMBOL(unregister_blkdev);
int blk_alloc_ext_minor(void){ int idx;
idx = ida_alloc_range(&ext_devt_ida, 0, NR_EXT_DEVT - 1, GFP_KERNEL); if (idx == -ENOSPC) return -EBUSY; return idx;}
void blk_free_ext_minor(unsigned int minor){ ida_free(&ext_devt_ida, minor);}
void disk_uevent(struct gendisk *disk, enum kobject_action action){ struct block_device *part; unsigned long idx;
rcu_read_lock(); xa_for_each(&disk->part_tbl, idx, part) { if (bdev_is_partition(part) && !bdev_nr_sectors(part)) continue; if (!kobject_get_unless_zero(&part->bd_device.kobj)) continue;
rcu_read_unlock(); kobject_uevent(bdev_kobj(part), action); put_device(&part->bd_device); rcu_read_lock(); } rcu_read_unlock();}EXPORT_SYMBOL_GPL(disk_uevent);
int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode){ struct file *file; int ret = 0;
if (!disk_has_partscan(disk)) return -EINVAL; if (disk->open_partitions) return -EBUSY;
/* * If the device is opened exclusively by current thread already, it's * safe to scan partitons, otherwise, use bd_prepare_to_claim() to * synchronize with other exclusive openers and other partition * scanners. */ if (!(mode & BLK_OPEN_EXCL)) { ret = bd_prepare_to_claim(disk->part0, disk_scan_partitions, NULL); if (ret) return ret; }
set_bit(GD_NEED_PART_SCAN, &disk->state); file = bdev_file_open_by_dev(disk_devt(disk), mode & ~BLK_OPEN_EXCL, NULL, NULL); if (IS_ERR(file)) ret = PTR_ERR(file); else fput(file);
/* * If blkdev_get_by_dev() failed early, GD_NEED_PART_SCAN is still set, * and this will cause that re-assemble partitioned raid device will * creat partition for underlying disk. */ clear_bit(GD_NEED_PART_SCAN, &disk->state); if (!(mode & BLK_OPEN_EXCL)) bd_abort_claiming(disk->part0, disk_scan_partitions); return ret;}
static void add_disk_final(struct gendisk *disk){ struct device *ddev = disk_to_dev(disk);
if (!(disk->flags & GENHD_FL_HIDDEN)) { bdev_add(disk->part0, ddev->devt); if (get_capacity(disk)) disk_scan_partitions(disk, BLK_OPEN_READ);
/* * Announce the disk and partitions after all partitions are * created. (for hidden disks uevents remain suppressed forever) */ dev_set_uevent_suppress(ddev, 0); disk_uevent(disk, KOBJ_ADD); }
blk_apply_bdi_limits(disk->bdi, &disk->queue->limits); disk_add_events(disk); set_bit(GD_ADDED, &disk->state);}
static int __add_disk(struct device *parent, struct gendisk *disk, const struct attribute_group **groups, struct fwnode_handle *fwnode)
{ struct device *ddev = disk_to_dev(disk); int ret;
if (WARN_ON_ONCE(bdev_nr_sectors(disk->part0) > BLK_DEV_MAX_SECTORS)) return -EINVAL;
if (queue_is_mq(disk->queue)) { /* * ->submit_bio and ->poll_bio are bypassed for blk-mq drivers. */ if (disk->fops->submit_bio || disk->fops->poll_bio) return -EINVAL; } else { if (!disk->fops->submit_bio) return -EINVAL; bdev_set_flag(disk->part0, BD_HAS_SUBMIT_BIO); }
/* * If the driver provides an explicit major number it also must provide * the number of minors numbers supported, and those will be used to * setup the gendisk. * Otherwise just allocate the device numbers for both the whole device * and all partitions from the extended dev_t space. */ ret = -EINVAL; if (disk->major) { if (WARN_ON(!disk->minors)) goto out;
if (disk->minors > DISK_MAX_PARTS) { pr_err("block: can't allocate more than %d partitions\n", DISK_MAX_PARTS); disk->minors = DISK_MAX_PARTS; } if (disk->first_minor > MINORMASK || disk->minors > MINORMASK + 1 || disk->first_minor + disk->minors > MINORMASK + 1) goto out; } else { if (WARN_ON(disk->minors)) goto out;
ret = blk_alloc_ext_minor(); if (ret < 0) goto out; disk->major = BLOCK_EXT_MAJOR; disk->first_minor = ret; }
/* delay uevents, until we scanned partition table */ dev_set_uevent_suppress(ddev, 1);
ddev->parent = parent; ddev->groups = groups; dev_set_name(ddev, "%s", disk->disk_name); if (fwnode) device_set_node(ddev, fwnode); if (!(disk->flags & GENHD_FL_HIDDEN)) ddev->devt = MKDEV(disk->major, disk->first_minor); ret = device_add(ddev); if (ret) goto out_free_ext_minor;
ret = disk_alloc_events(disk); if (ret) goto out_device_del;
ret = sysfs_create_link(block_depr, &ddev->kobj, kobject_name(&ddev->kobj)); if (ret) goto out_device_del;
/* * avoid probable deadlock caused by allocating memory with * GFP_KERNEL in runtime_resume callback of its all ancestor * devices */ pm_runtime_set_memalloc_noio(ddev, true);
disk->part0->bd_holder_dir = kobject_create_and_add("holders", &ddev->kobj); if (!disk->part0->bd_holder_dir) { ret = -ENOMEM; goto out_del_block_link; } disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj); if (!disk->slave_dir) { ret = -ENOMEM; goto out_put_holder_dir; }
ret = blk_register_queue(disk); if (ret) goto out_put_slave_dir;
if (!(disk->flags & GENHD_FL_HIDDEN)) { ret = bdi_register(disk->bdi, "%u:%u", disk->major, disk->first_minor); if (ret) goto out_unregister_queue; bdi_set_owner(disk->bdi, ddev); ret = sysfs_create_link(&ddev->kobj, &disk->bdi->dev->kobj, "bdi"); if (ret) goto out_unregister_bdi; } else { /* * Even if the block_device for a hidden gendisk is not * registered, it needs to have a valid bd_dev so that the * freeing of the dynamic major works. */ disk->part0->bd_dev = MKDEV(disk->major, disk->first_minor); } return 0;
out_unregister_bdi: if (!(disk->flags & GENHD_FL_HIDDEN)) bdi_unregister(disk->bdi);out_unregister_queue: blk_unregister_queue(disk); rq_qos_exit(disk->queue);out_put_slave_dir: kobject_put(disk->slave_dir); disk->slave_dir = NULL;out_put_holder_dir: kobject_put(disk->part0->bd_holder_dir);out_del_block_link: sysfs_remove_link(block_depr, dev_name(ddev)); pm_runtime_set_memalloc_noio(ddev, false);out_device_del: device_del(ddev);out_free_ext_minor: if (disk->major == BLOCK_EXT_MAJOR) blk_free_ext_minor(disk->first_minor);out: return ret;}
/** * add_disk_fwnode - add disk information to kernel list with fwnode * @parent: parent device for the disk * @disk: per-device partitioning information * @groups: Additional per-device sysfs groups * @fwnode: attached disk fwnode * * This function registers the partitioning information in @disk * with the kernel. Also attach a fwnode to the disk device. */int __must_check add_disk_fwnode(struct device *parent, struct gendisk *disk, const struct attribute_group **groups, struct fwnode_handle *fwnode){ struct blk_mq_tag_set *set; unsigned int memflags; int ret;
if (queue_is_mq(disk->queue)) { set = disk->queue->tag_set; memflags = memalloc_noio_save(); down_read(&set->update_nr_hwq_lock); ret = __add_disk(parent, disk, groups, fwnode); up_read(&set->update_nr_hwq_lock); memalloc_noio_restore(memflags); } else { ret = __add_disk(parent, disk, groups, fwnode); }
/* * add_disk_final() needn't to read `nr_hw_queues`, so move it out * of read lock `set->update_nr_hwq_lock` for avoiding unnecessary * lock dependency on `disk->open_mutex` from scanning partition. */ if (!ret) add_disk_final(disk); return ret;}EXPORT_SYMBOL_GPL(add_disk_fwnode);
/** * device_add_disk - add disk information to kernel list * @parent: parent device for the disk * @disk: per-device partitioning information * @groups: Additional per-device sysfs groups * * This function registers the partitioning information in @disk * with the kernel. */int __must_check device_add_disk(struct device *parent, struct gendisk *disk, const struct attribute_group **groups){ return add_disk_fwnode(parent, disk, groups, NULL);}EXPORT_SYMBOL(device_add_disk);
static void blk_report_disk_dead(struct gendisk *disk, bool surprise){ struct block_device *bdev; unsigned long idx;
/* * On surprise disk removal, bdev_mark_dead() may call into file * systems below. Make it clear that we're expecting to not hold * disk->open_mutex. */ lockdep_assert_not_held(&disk->open_mutex);
rcu_read_lock(); xa_for_each(&disk->part_tbl, idx, bdev) { if (!kobject_get_unless_zero(&bdev->bd_device.kobj)) continue; rcu_read_unlock();
bdev_mark_dead(bdev, surprise);
put_device(&bdev->bd_device); rcu_read_lock(); } rcu_read_unlock();}
static bool __blk_mark_disk_dead(struct gendisk *disk){ /* * Fail any new I/O. */ if (test_and_set_bit(GD_DEAD, &disk->state)) return false;
if (test_bit(GD_OWNS_QUEUE, &disk->state)) blk_queue_flag_set(QUEUE_FLAG_DYING, disk->queue);
/* * Stop buffered writers from dirtying pages that can't be written out. */ set_capacity(disk, 0);
/* * Prevent new I/O from crossing bio_queue_enter(). */ return blk_queue_start_drain(disk->queue);}
/** * blk_mark_disk_dead - mark a disk as dead * @disk: disk to mark as dead * * Mark as disk as dead (e.g. surprise removed) and don't accept any new I/O * to this disk. */void blk_mark_disk_dead(struct gendisk *disk){ __blk_mark_disk_dead(disk); blk_report_disk_dead(disk, true);}EXPORT_SYMBOL_GPL(blk_mark_disk_dead);
static void __del_gendisk(struct gendisk *disk){ struct request_queue *q = disk->queue; struct block_device *part; unsigned long idx; bool start_drain;
might_sleep();
if (WARN_ON_ONCE(!disk_live(disk) && !(disk->flags & GENHD_FL_HIDDEN))) return;
disk_del_events(disk);
/* * Prevent new openers by unlinked the bdev inode. */ mutex_lock(&disk->open_mutex); xa_for_each(&disk->part_tbl, idx, part) bdev_unhash(part); mutex_unlock(&disk->open_mutex);
/* * Tell the file system to write back all dirty data and shut down if * it hasn't been notified earlier. */ if (!test_bit(GD_DEAD, &disk->state)) blk_report_disk_dead(disk, false);
/* * Drop all partitions now that the disk is marked dead. */ mutex_lock(&disk->open_mutex); start_drain = __blk_mark_disk_dead(disk); if (start_drain) blk_freeze_acquire_lock(q); xa_for_each_start(&disk->part_tbl, idx, part, 1) drop_partition(part); mutex_unlock(&disk->open_mutex);
if (!(disk->flags & GENHD_FL_HIDDEN)) { sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
/* * Unregister bdi before releasing device numbers (as they can * get reused and we'd get clashes in sysfs). */ bdi_unregister(disk->bdi); }
blk_unregister_queue(disk);
kobject_put(disk->part0->bd_holder_dir); kobject_put(disk->slave_dir); disk->slave_dir = NULL;
part_stat_set_all(disk->part0, 0); disk->part0->bd_stamp = 0; sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk))); pm_runtime_set_memalloc_noio(disk_to_dev(disk), false); device_del(disk_to_dev(disk));
blk_mq_freeze_queue_wait(q);
blk_throtl_cancel_bios(disk);
blk_sync_queue(q); blk_flush_integrity();
if (queue_is_mq(q)) blk_mq_cancel_work_sync(q);
rq_qos_exit(q);
/* * If the disk does not own the queue, allow using passthrough requests * again. Else leave the queue frozen to fail all I/O. */ if (!test_bit(GD_OWNS_QUEUE, &disk->state)) __blk_mq_unfreeze_queue(q, true); else if (queue_is_mq(q)) blk_mq_exit_queue(q);
if (start_drain) blk_unfreeze_release_lock(q);}
static void disable_elv_switch(struct request_queue *q){ struct blk_mq_tag_set *set = q->tag_set; WARN_ON_ONCE(!queue_is_mq(q));
down_write(&set->update_nr_hwq_lock); blk_queue_flag_set(QUEUE_FLAG_NO_ELV_SWITCH, q); up_write(&set->update_nr_hwq_lock);}
/** * del_gendisk - remove the gendisk * @disk: the struct gendisk to remove * * Removes the gendisk and all its associated resources. This deletes the * partitions associated with the gendisk, and unregisters the associated * request_queue. * * This is the counter to the respective device_add_disk() call. * * The final removal of the struct gendisk happens when its refcount reaches 0 * with put_disk(), which should be called after del_gendisk(), if * device_add_disk() was used. * * Drivers exist which depend on the release of the gendisk to be synchronous, * it should not be deferred. * * Context: can sleep */void del_gendisk(struct gendisk *disk){ struct blk_mq_tag_set *set; unsigned int memflags;
if (!queue_is_mq(disk->queue)) { __del_gendisk(disk); } else { set = disk->queue->tag_set;
disable_elv_switch(disk->queue);
memflags = memalloc_noio_save(); down_read(&set->update_nr_hwq_lock); __del_gendisk(disk); up_read(&set->update_nr_hwq_lock); memalloc_noio_restore(memflags); }}EXPORT_SYMBOL(del_gendisk);
/** * invalidate_disk - invalidate the disk * @disk: the struct gendisk to invalidate * * A helper to invalidates the disk. It will clean the disk's associated * buffer/page caches and reset its internal states so that the disk * can be reused by the drivers. * * Context: can sleep */void invalidate_disk(struct gendisk *disk){ struct block_device *bdev = disk->part0;
invalidate_bdev(bdev); bdev->bd_mapping->wb_err = 0; set_capacity(disk, 0);}EXPORT_SYMBOL(invalidate_disk);
/* sysfs access to bad-blocks list. */static ssize_t disk_badblocks_show(struct device *dev, struct device_attribute *attr, char *page){ struct gendisk *disk = dev_to_disk(dev);
if (!disk->bb) return sysfs_emit(page, "\n");
return badblocks_show(disk->bb, page, 0);}
static ssize_t disk_badblocks_store(struct device *dev, struct device_attribute *attr, const char *page, size_t len){ struct gendisk *disk = dev_to_disk(dev);
if (!disk->bb) return -ENXIO;
return badblocks_store(disk->bb, page, len, 0);}
#ifdef CONFIG_BLOCK_LEGACY_AUTOLOADstatic bool blk_probe_dev(dev_t devt){ unsigned int major = MAJOR(devt); struct blk_major_name **n;
mutex_lock(&major_names_lock); for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) { if ((*n)->major == major && (*n)->probe) { (*n)->probe(devt); mutex_unlock(&major_names_lock); return true; } } mutex_unlock(&major_names_lock); return false;}
void blk_request_module(dev_t devt){ int error;
if (blk_probe_dev(devt)) return;
error = request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)); /* Make old-style 2.4 aliases work */ if (error > 0) error = request_module("block-major-%d", MAJOR(devt)); if (!error) blk_probe_dev(devt);}#endif /* CONFIG_BLOCK_LEGACY_AUTOLOAD */
#ifdef CONFIG_PROC_FS/* iterator */static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos){ loff_t skip = *pos; struct class_dev_iter *iter; struct device *dev;
iter = kmalloc_obj(*iter); if (!iter) return ERR_PTR(-ENOMEM);
seqf->private = iter; class_dev_iter_init(iter, &block_class, NULL, &disk_type); do { dev = class_dev_iter_next(iter); if (!dev) return NULL; } while (skip--);
return dev_to_disk(dev);}
static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos){ struct device *dev;
(*pos)++; dev = class_dev_iter_next(seqf->private); if (dev) return dev_to_disk(dev);
return NULL;}
static void disk_seqf_stop(struct seq_file *seqf, void *v){ struct class_dev_iter *iter = seqf->private;
/* stop is called even after start failed :-( */ if (iter) { class_dev_iter_exit(iter); kfree(iter); seqf->private = NULL; }}
static void *show_partition_start(struct seq_file *seqf, loff_t *pos){ void *p;
p = disk_seqf_start(seqf, pos); if (!IS_ERR_OR_NULL(p) && !*pos) seq_puts(seqf, "major minor #blocks name\n\n"); return p;}
static int show_partition(struct seq_file *seqf, void *v){ struct gendisk *sgp = v; struct block_device *part; unsigned long idx;
if (!get_capacity(sgp) || (sgp->flags & GENHD_FL_HIDDEN)) return 0;
rcu_read_lock(); xa_for_each(&sgp->part_tbl, idx, part) { if (!bdev_nr_sectors(part)) continue; seq_printf(seqf, "%4d %7d %10llu %pg\n", MAJOR(part->bd_dev), MINOR(part->bd_dev), bdev_nr_sectors(part) >> 1, part); } rcu_read_unlock(); return 0;}
static const struct seq_operations partitions_op = { .start = show_partition_start, .next = disk_seqf_next, .stop = disk_seqf_stop, .show = show_partition};#endif
static int __init genhd_device_init(void){ int error;
error = class_register(&block_class); if (unlikely(error)) return error; blk_dev_init();
register_blkdev(BLOCK_EXT_MAJOR, "blkext");
/* create top-level block dir */ block_depr = kobject_create_and_add("block", NULL); return 0;}
subsys_initcall(genhd_device_init);
static ssize_t disk_range_show(struct device *dev, struct device_attribute *attr, char *buf){ struct gendisk *disk = dev_to_disk(dev);
return sysfs_emit(buf, "%d\n", disk->minors);}
static ssize_t disk_ext_range_show(struct device *dev, struct device_attribute *attr, char *buf){ struct gendisk *disk = dev_to_disk(dev);
return sysfs_emit(buf, "%d\n", (disk->flags & GENHD_FL_NO_PART) ? 1 : DISK_MAX_PARTS);}
static ssize_t disk_removable_show(struct device *dev, struct device_attribute *attr, char *buf){ struct gendisk *disk = dev_to_disk(dev);
return sysfs_emit(buf, "%d\n", (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));}
static ssize_t disk_hidden_show(struct device *dev, struct device_attribute *attr, char *buf){ struct gendisk *disk = dev_to_disk(dev);
return sysfs_emit(buf, "%d\n", (disk->flags & GENHD_FL_HIDDEN ? 1 : 0));}
static ssize_t disk_ro_show(struct device *dev, struct device_attribute *attr, char *buf){ struct gendisk *disk = dev_to_disk(dev);
return sysfs_emit(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);}
ssize_t part_size_show(struct device *dev, struct device_attribute *attr, char *buf){ return sysfs_emit(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev)));}
ssize_t part_stat_show(struct device *dev, struct device_attribute *attr, char *buf){ struct block_device *bdev = dev_to_bdev(dev); struct disk_stats stat; unsigned int inflight;
inflight = bdev_count_inflight(bdev); if (inflight) { part_stat_lock(); update_io_ticks(bdev, jiffies, true); part_stat_unlock(); } part_stat_read_all(bdev, &stat); return sysfs_emit(buf, "%8lu %8lu %8llu %8u " "%8lu %8lu %8llu %8u " "%8u %8u %8u " "%8lu %8lu %8llu %8u " "%8lu %8u" "\n", stat.ios[STAT_READ], stat.merges[STAT_READ], (unsigned long long)stat.sectors[STAT_READ], (unsigned int)div_u64(stat.nsecs[STAT_READ], NSEC_PER_MSEC), stat.ios[STAT_WRITE], stat.merges[STAT_WRITE], (unsigned long long)stat.sectors[STAT_WRITE], (unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC), inflight, jiffies_to_msecs(stat.io_ticks), (unsigned int)div_u64(stat.nsecs[STAT_READ] + stat.nsecs[STAT_WRITE] + stat.nsecs[STAT_DISCARD] + stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC), stat.ios[STAT_DISCARD], stat.merges[STAT_DISCARD], (unsigned long long)stat.sectors[STAT_DISCARD], (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], NSEC_PER_MSEC), stat.ios[STAT_FLUSH], (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC));}
/* * Show the number of IOs issued to driver. * For bio-based device, started from bdev_start_io_acct(); * For rq-based device, started from blk_mq_start_request(); */ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr, char *buf){ struct block_device *bdev = dev_to_bdev(dev); struct request_queue *q = bdev_get_queue(bdev); unsigned int inflight[2] = {0};
bdev_count_inflight_rw(bdev, inflight, queue_is_mq(q));
return sysfs_emit(buf, "%8u %8u\n", inflight[READ], inflight[WRITE]);}
static ssize_t disk_capability_show(struct device *dev, struct device_attribute *attr, char *buf){ dev_warn_once(dev, "the capability attribute has been deprecated.\n"); return sysfs_emit(buf, "0\n");}
static ssize_t disk_alignment_offset_show(struct device *dev, struct device_attribute *attr, char *buf){ struct gendisk *disk = dev_to_disk(dev);
return sysfs_emit(buf, "%d\n", bdev_alignment_offset(disk->part0));}
static ssize_t disk_discard_alignment_show(struct device *dev, struct device_attribute *attr, char *buf){ struct gendisk *disk = dev_to_disk(dev);
return sysfs_emit(buf, "%d\n", bdev_alignment_offset(disk->part0));}
static ssize_t diskseq_show(struct device *dev, struct device_attribute *attr, char *buf){ struct gendisk *disk = dev_to_disk(dev);
return sysfs_emit(buf, "%llu\n", disk->diskseq);}
static ssize_t partscan_show(struct device *dev, struct device_attribute *attr, char *buf){ return sysfs_emit(buf, "%u\n", disk_has_partscan(dev_to_disk(dev)));}
static DEVICE_ATTR(range, 0444, disk_range_show, NULL);static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL);static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL);static DEVICE_ATTR(hidden, 0444, disk_hidden_show, NULL);static DEVICE_ATTR(ro, 0444, disk_ro_show, NULL);static DEVICE_ATTR(size, 0444, part_size_show, NULL);static DEVICE_ATTR(alignment_offset, 0444, disk_alignment_offset_show, NULL);static DEVICE_ATTR(discard_alignment, 0444, disk_discard_alignment_show, NULL);static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL);static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store);static DEVICE_ATTR(diskseq, 0444, diskseq_show, NULL);static DEVICE_ATTR(partscan, 0444, partscan_show, NULL);
#ifdef CONFIG_FAIL_MAKE_REQUESTssize_t part_fail_show(struct device *dev, struct device_attribute *attr, char *buf){ return sysfs_emit(buf, "%d\n", bdev_test_flag(dev_to_bdev(dev), BD_MAKE_IT_FAIL));}
ssize_t part_fail_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count){ int i;
if (count > 0 && sscanf(buf, "%d", &i) > 0) { if (i) bdev_set_flag(dev_to_bdev(dev), BD_MAKE_IT_FAIL); else bdev_clear_flag(dev_to_bdev(dev), BD_MAKE_IT_FAIL); } return count;}
static struct device_attribute dev_attr_fail = __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);#endif /* CONFIG_FAIL_MAKE_REQUEST */
#ifdef CONFIG_FAIL_IO_TIMEOUTstatic struct device_attribute dev_attr_fail_timeout = __ATTR(io-timeout-fail, 0644, part_timeout_show, part_timeout_store);#endif
static struct attribute *disk_attrs[] = { &dev_attr_range.attr, &dev_attr_ext_range.attr, &dev_attr_removable.attr, &dev_attr_hidden.attr, &dev_attr_ro.attr, &dev_attr_size.attr, &dev_attr_alignment_offset.attr, &dev_attr_discard_alignment.attr, &dev_attr_capability.attr, &dev_attr_stat.attr, &dev_attr_inflight.attr, &dev_attr_badblocks.attr, &dev_attr_events.attr, &dev_attr_events_async.attr, &dev_attr_events_poll_msecs.attr, &dev_attr_diskseq.attr, &dev_attr_partscan.attr,#ifdef CONFIG_FAIL_MAKE_REQUEST &dev_attr_fail.attr,#endif#ifdef CONFIG_FAIL_IO_TIMEOUT &dev_attr_fail_timeout.attr,#endif NULL};
static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n){ struct device *dev = container_of(kobj, typeof(*dev), kobj); struct gendisk *disk = dev_to_disk(dev);
if (a == &dev_attr_badblocks.attr && !disk->bb) return 0; return a->mode;}
static struct attribute_group disk_attr_group = { .attrs = disk_attrs, .is_visible = disk_visible,};
static const struct attribute_group *disk_attr_groups[] = { &disk_attr_group,#ifdef CONFIG_BLK_DEV_IO_TRACE &blk_trace_attr_group,#endif#ifdef CONFIG_BLK_DEV_INTEGRITY &blk_integrity_attr_group,#endif NULL};
/** * disk_release - releases all allocated resources of the gendisk * @dev: the device representing this disk * * This function releases all allocated resources of the gendisk. * * Drivers which used device_add_disk() have a gendisk with a request_queue * assigned. Since the request_queue sits on top of the gendisk for these * drivers we also call blk_put_queue() for them, and we expect the * request_queue refcount to reach 0 at this point, and so the request_queue * will also be freed prior to the disk. * * Context: can sleep */static void disk_release(struct device *dev){ struct gendisk *disk = dev_to_disk(dev);
might_sleep(); WARN_ON_ONCE(disk_live(disk));
blk_trace_remove(disk->queue);
/* * To undo the all initialization from blk_mq_init_allocated_queue in * case of a probe failure where add_disk is never called we have to * call blk_mq_exit_queue here. We can't do this for the more common * teardown case (yet) as the tagset can be gone by the time the disk * is released once it was added. */ if (queue_is_mq(disk->queue) && test_bit(GD_OWNS_QUEUE, &disk->state) && !test_bit(GD_ADDED, &disk->state)) blk_mq_exit_queue(disk->queue);
blkcg_exit_disk(disk);
bioset_exit(&disk->bio_split);
disk_release_events(disk); kfree(disk->random); disk_release_zone_resources(disk); xa_destroy(&disk->part_tbl);
kobject_put(&disk->queue_kobj); disk->queue->disk = NULL; blk_put_queue(disk->queue);
if (test_bit(GD_ADDED, &disk->state) && disk->fops->free_disk) disk->fops->free_disk(disk);
bdev_drop(disk->part0); /* frees the disk */}
static int block_uevent(const struct device *dev, struct kobj_uevent_env *env){ const struct gendisk *disk = dev_to_disk(dev);
return add_uevent_var(env, "DISKSEQ=%llu", disk->diskseq);}
const struct class block_class = { .name = "block", .dev_uevent = block_uevent,};
static char *block_devnode(const struct device *dev, umode_t *mode, kuid_t *uid, kgid_t *gid){ struct gendisk *disk = dev_to_disk(dev);
if (disk->fops->devnode) return disk->fops->devnode(disk, mode); return NULL;}
const struct device_type disk_type = { .name = "disk", .groups = disk_attr_groups, .release = disk_release, .devnode = block_devnode,};
#ifdef CONFIG_PROC_FS/* * aggregate disk stat collector. Uses the same stats that the sysfs * entries do, above, but makes them available through one seq_file. * * The output looks suspiciously like /proc/partitions with a bunch of * extra fields. */static int diskstats_show(struct seq_file *seqf, void *v){ struct gendisk *gp = v; struct block_device *hd; unsigned int inflight; struct disk_stats stat; unsigned long idx;
/* if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next) seq_puts(seqf, "major minor name" " rio rmerge rsect ruse wio wmerge " "wsect wuse running use aveq" "\n\n"); */
rcu_read_lock(); xa_for_each(&gp->part_tbl, idx, hd) { if (bdev_is_partition(hd) && !bdev_nr_sectors(hd)) continue;
inflight = bdev_count_inflight(hd); if (inflight) { part_stat_lock(); update_io_ticks(hd, jiffies, true); part_stat_unlock(); } part_stat_read_all(hd, &stat); seq_put_decimal_ull_width(seqf, "", MAJOR(hd->bd_dev), 4); seq_put_decimal_ull_width(seqf, " ", MINOR(hd->bd_dev), 7); seq_printf(seqf, " %pg", hd); seq_put_decimal_ull(seqf, " ", stat.ios[STAT_READ]); seq_put_decimal_ull(seqf, " ", stat.merges[STAT_READ]); seq_put_decimal_ull(seqf, " ", stat.sectors[STAT_READ]); seq_put_decimal_ull(seqf, " ", (unsigned int)div_u64(stat.nsecs[STAT_READ], NSEC_PER_MSEC)); seq_put_decimal_ull(seqf, " ", stat.ios[STAT_WRITE]); seq_put_decimal_ull(seqf, " ", stat.merges[STAT_WRITE]); seq_put_decimal_ull(seqf, " ", stat.sectors[STAT_WRITE]); seq_put_decimal_ull(seqf, " ", (unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC)); seq_put_decimal_ull(seqf, " ", inflight); seq_put_decimal_ull(seqf, " ", jiffies_to_msecs(stat.io_ticks)); seq_put_decimal_ull(seqf, " ", (unsigned int)div_u64(stat.nsecs[STAT_READ] + stat.nsecs[STAT_WRITE] + stat.nsecs[STAT_DISCARD] + stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC)); seq_put_decimal_ull(seqf, " ", stat.ios[STAT_DISCARD]); seq_put_decimal_ull(seqf, " ", stat.merges[STAT_DISCARD]); seq_put_decimal_ull(seqf, " ", stat.sectors[STAT_DISCARD]); seq_put_decimal_ull(seqf, " ", (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], NSEC_PER_MSEC)); seq_put_decimal_ull(seqf, " ", stat.ios[STAT_FLUSH]); seq_put_decimal_ull(seqf, " ", (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC)); seq_putc(seqf, '\n'); } rcu_read_unlock();
return 0;}
static const struct seq_operations diskstats_op = { .start = disk_seqf_start, .next = disk_seqf_next, .stop = disk_seqf_stop, .show = diskstats_show};
static int __init proc_genhd_init(void){ proc_create_seq("diskstats", 0, NULL, &diskstats_op); proc_create_seq("partitions", 0, NULL, &partitions_op); return 0;}module_init(proc_genhd_init);#endif /* CONFIG_PROC_FS */
dev_t part_devt(struct gendisk *disk, u8 partno){ struct block_device *part; dev_t devt = 0;
rcu_read_lock(); part = xa_load(&disk->part_tbl, partno); if (part) devt = part->bd_dev; rcu_read_unlock();
return devt;}
struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id, struct lock_class_key *lkclass){ struct gendisk *disk;
disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id); if (!disk) return NULL;
if (bioset_init(&disk->bio_split, BIO_POOL_SIZE, 0, 0)) goto out_free_disk;
disk->bdi = bdi_alloc(node_id); if (!disk->bdi) goto out_free_bioset;
/* bdev_alloc() might need the queue, set before the first call */ disk->queue = q;
disk->part0 = bdev_alloc(disk, 0); if (!disk->part0) goto out_free_bdi;
disk->node_id = node_id; mutex_init(&disk->open_mutex); xa_init(&disk->part_tbl); if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL)) goto out_destroy_part_tbl;
if (blkcg_init_disk(disk)) goto out_erase_part0;
disk_init_zone_resources(disk); rand_initialize_disk(disk); disk_to_dev(disk)->class = &block_class; disk_to_dev(disk)->type = &disk_type; device_initialize(disk_to_dev(disk)); inc_diskseq(disk); q->disk = disk; lockdep_init_map(&disk->lockdep_map, "(bio completion)", lkclass, 0);#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED INIT_LIST_HEAD(&disk->slave_bdevs);#endif#ifdef CONFIG_BLK_ERROR_INJECTION mutex_init(&disk->error_injection_lock); INIT_LIST_HEAD(&disk->error_injection_list);#endif mutex_init(&disk->rqos_state_mutex); kobject_init(&disk->queue_kobj, &blk_queue_ktype); return disk;
out_erase_part0: xa_erase(&disk->part_tbl, 0);out_destroy_part_tbl: xa_destroy(&disk->part_tbl); disk->part0->bd_disk = NULL; bdev_drop(disk->part0);out_free_bdi: bdi_put(disk->bdi);out_free_bioset: bioset_exit(&disk->bio_split);out_free_disk: kfree(disk); return NULL;}
struct gendisk *__blk_alloc_disk(struct queue_limits *lim, int node, struct lock_class_key *lkclass){ struct queue_limits default_lim = { }; struct request_queue *q; struct gendisk *disk;
q = blk_alloc_queue(lim ? lim : &default_lim, node); if (IS_ERR(q)) return ERR_CAST(q);
disk = __alloc_disk_node(q, node, lkclass); if (!disk) { blk_put_queue(q); return ERR_PTR(-ENOMEM); } set_bit(GD_OWNS_QUEUE, &disk->state); return disk;}EXPORT_SYMBOL(__blk_alloc_disk);
/** * put_disk - decrements the gendisk refcount * @disk: the struct gendisk to decrement the refcount for * * This decrements the refcount for the struct gendisk. When this reaches 0 * we'll have disk_release() called. * * Note: for blk-mq disk put_disk must be called before freeing the tag_set * when handling probe errors (that is before add_disk() is called). * * Context: Any context, but the last reference must not be dropped from * atomic context. */void put_disk(struct gendisk *disk){ if (disk) put_device(disk_to_dev(disk));}EXPORT_SYMBOL(put_disk);
static void set_disk_ro_uevent(struct gendisk *gd, int ro){ char event[] = "DISK_RO=1"; char *envp[] = { event, NULL };
if (!ro) event[8] = '0'; kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);}
/** * set_disk_ro - set a gendisk read-only * @disk: gendisk to operate on * @read_only: %true to set the disk read-only, %false set the disk read/write * * This function is used to indicate whether a given disk device should have its * read-only flag set. set_disk_ro() is typically used by device drivers to * indicate whether the underlying physical device is write-protected. */void set_disk_ro(struct gendisk *disk, bool read_only){ if (read_only) { if (test_and_set_bit(GD_READ_ONLY, &disk->state)) return; } else { if (!test_and_clear_bit(GD_READ_ONLY, &disk->state)) return; } set_disk_ro_uevent(disk, read_only);}EXPORT_SYMBOL(set_disk_ro);
void inc_diskseq(struct gendisk *disk){ disk->diskseq = atomic64_inc_return(&diskseq);}