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- // SPDX-License-Identifier: GPL-2.0
- /*
- * gendisk handling
- */
- #include <linux/module.h>
- #include <linux/ctype.h>
- #include <linux/fs.h>
- #include <linux/genhd.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/kobj_map.h>
- #include <linux/mutex.h>
- #include <linux/idr.h>
- #include <linux/log2.h>
- #include <linux/pm_runtime.h>
- #include <linux/badblocks.h>
- #include "blk.h"
- static DEFINE_MUTEX(block_class_lock);
- static struct kobject *block_depr;
- /* for extended dynamic devt allocation, currently only one major is used */
- #define NR_EXT_DEVT (1 << MINORBITS)
- /* For extended devt allocation. ext_devt_lock prevents look up
- * results from going away underneath its user.
- */
- static DEFINE_SPINLOCK(ext_devt_lock);
- static DEFINE_IDR(ext_devt_idr);
- static void disk_check_events(struct disk_events *ev,
- unsigned int *clearing_ptr);
- static void disk_alloc_events(struct gendisk *disk);
- static void disk_add_events(struct gendisk *disk);
- static void disk_del_events(struct gendisk *disk);
- static void disk_release_events(struct gendisk *disk);
- /*
- * Set disk capacity and notify if the size is not currently
- * zero and will not be set to zero
- */
- bool set_capacity_revalidate_and_notify(struct gendisk *disk, sector_t size,
- bool update_bdev)
- {
- sector_t capacity = get_capacity(disk);
- set_capacity(disk, size);
- if (update_bdev)
- revalidate_disk_size(disk, true);
- if (capacity != size && capacity != 0 && size != 0) {
- char *envp[] = { "RESIZE=1", NULL };
- kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
- return true;
- }
- return false;
- }
- EXPORT_SYMBOL_GPL(set_capacity_revalidate_and_notify);
- /*
- * Format the device name of the indicated disk into the supplied buffer and
- * return a pointer to that same buffer for convenience.
- */
- char *disk_name(struct gendisk *hd, int partno, char *buf)
- {
- if (!partno)
- snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
- else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
- snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
- else
- snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
- return buf;
- }
- const char *bdevname(struct block_device *bdev, char *buf)
- {
- return disk_name(bdev->bd_disk, bdev->bd_partno, buf);
- }
- EXPORT_SYMBOL(bdevname);
- static void part_stat_read_all(struct hd_struct *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->dkstats, 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 unsigned int part_in_flight(struct hd_struct *part)
- {
- unsigned int inflight = 0;
- int cpu;
- for_each_possible_cpu(cpu) {
- inflight += part_stat_local_read_cpu(part, in_flight[0], cpu) +
- part_stat_local_read_cpu(part, in_flight[1], cpu);
- }
- if ((int)inflight < 0)
- inflight = 0;
- return inflight;
- }
- static void part_in_flight_rw(struct hd_struct *part, unsigned int inflight[2])
- {
- int cpu;
- inflight[0] = 0;
- inflight[1] = 0;
- for_each_possible_cpu(cpu) {
- inflight[0] += part_stat_local_read_cpu(part, in_flight[0], cpu);
- inflight[1] += part_stat_local_read_cpu(part, in_flight[1], cpu);
- }
- if ((int)inflight[0] < 0)
- inflight[0] = 0;
- if ((int)inflight[1] < 0)
- inflight[1] = 0;
- }
- struct hd_struct *__disk_get_part(struct gendisk *disk, int partno)
- {
- struct disk_part_tbl *ptbl = rcu_dereference(disk->part_tbl);
- if (unlikely(partno < 0 || partno >= ptbl->len))
- return NULL;
- return rcu_dereference(ptbl->part[partno]);
- }
- /**
- * disk_get_part - get partition
- * @disk: disk to look partition from
- * @partno: partition number
- *
- * Look for partition @partno from @disk. If found, increment
- * reference count and return it.
- *
- * CONTEXT:
- * Don't care.
- *
- * RETURNS:
- * Pointer to the found partition on success, NULL if not found.
- */
- struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
- {
- struct hd_struct *part;
- rcu_read_lock();
- part = __disk_get_part(disk, partno);
- if (part)
- get_device(part_to_dev(part));
- rcu_read_unlock();
- return part;
- }
- /**
- * disk_part_iter_init - initialize partition iterator
- * @piter: iterator to initialize
- * @disk: disk to iterate over
- * @flags: DISK_PITER_* flags
- *
- * Initialize @piter so that it iterates over partitions of @disk.
- *
- * CONTEXT:
- * Don't care.
- */
- void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
- unsigned int flags)
- {
- struct disk_part_tbl *ptbl;
- rcu_read_lock();
- ptbl = rcu_dereference(disk->part_tbl);
- piter->disk = disk;
- piter->part = NULL;
- if (flags & DISK_PITER_REVERSE)
- piter->idx = ptbl->len - 1;
- else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0))
- piter->idx = 0;
- else
- piter->idx = 1;
- piter->flags = flags;
- rcu_read_unlock();
- }
- EXPORT_SYMBOL_GPL(disk_part_iter_init);
- /**
- * disk_part_iter_next - proceed iterator to the next partition and return it
- * @piter: iterator of interest
- *
- * Proceed @piter to the next partition and return it.
- *
- * CONTEXT:
- * Don't care.
- */
- struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
- {
- struct disk_part_tbl *ptbl;
- int inc, end;
- /* put the last partition */
- disk_put_part(piter->part);
- piter->part = NULL;
- /* get part_tbl */
- rcu_read_lock();
- ptbl = rcu_dereference(piter->disk->part_tbl);
- /* determine iteration parameters */
- if (piter->flags & DISK_PITER_REVERSE) {
- inc = -1;
- if (piter->flags & (DISK_PITER_INCL_PART0 |
- DISK_PITER_INCL_EMPTY_PART0))
- end = -1;
- else
- end = 0;
- } else {
- inc = 1;
- end = ptbl->len;
- }
- /* iterate to the next partition */
- for (; piter->idx != end; piter->idx += inc) {
- struct hd_struct *part;
- part = rcu_dereference(ptbl->part[piter->idx]);
- if (!part)
- continue;
- get_device(part_to_dev(part));
- piter->part = part;
- if (!part_nr_sects_read(part) &&
- !(piter->flags & DISK_PITER_INCL_EMPTY) &&
- !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 &&
- piter->idx == 0)) {
- put_device(part_to_dev(part));
- piter->part = NULL;
- continue;
- }
- piter->idx += inc;
- break;
- }
- rcu_read_unlock();
- return piter->part;
- }
- EXPORT_SYMBOL_GPL(disk_part_iter_next);
- /**
- * disk_part_iter_exit - finish up partition iteration
- * @piter: iter of interest
- *
- * Called when iteration is over. Cleans up @piter.
- *
- * CONTEXT:
- * Don't care.
- */
- void disk_part_iter_exit(struct disk_part_iter *piter)
- {
- disk_put_part(piter->part);
- piter->part = NULL;
- }
- EXPORT_SYMBOL_GPL(disk_part_iter_exit);
- static inline int sector_in_part(struct hd_struct *part, sector_t sector)
- {
- return part->start_sect <= sector &&
- sector < part->start_sect + part_nr_sects_read(part);
- }
- /**
- * disk_map_sector_rcu - map sector to partition
- * @disk: gendisk of interest
- * @sector: sector to map
- *
- * Find out which partition @sector maps to on @disk. This is
- * primarily used for stats accounting.
- *
- * CONTEXT:
- * RCU read locked. The returned partition pointer is always valid
- * because its refcount is grabbed except for part0, which lifetime
- * is same with the disk.
- *
- * RETURNS:
- * Found partition on success, part0 is returned if no partition matches
- * or the matched partition is being deleted.
- */
- struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
- {
- struct disk_part_tbl *ptbl;
- struct hd_struct *part;
- int i;
- rcu_read_lock();
- ptbl = rcu_dereference(disk->part_tbl);
- part = rcu_dereference(ptbl->last_lookup);
- if (part && sector_in_part(part, sector) && hd_struct_try_get(part))
- goto out_unlock;
- for (i = 1; i < ptbl->len; i++) {
- part = rcu_dereference(ptbl->part[i]);
- if (part && sector_in_part(part, sector)) {
- /*
- * only live partition can be cached for lookup,
- * so use-after-free on cached & deleting partition
- * can be avoided
- */
- if (!hd_struct_try_get(part))
- break;
- rcu_assign_pointer(ptbl->last_lookup, part);
- goto out_unlock;
- }
- }
- part = &disk->part0;
- out_unlock:
- rcu_read_unlock();
- return part;
- }
- /**
- * disk_has_partitions
- * @disk: gendisk of interest
- *
- * Walk through the partition table and check if valid partition exists.
- *
- * CONTEXT:
- * Don't care.
- *
- * RETURNS:
- * True if the gendisk has at least one valid non-zero size partition.
- * Otherwise false.
- */
- bool disk_has_partitions(struct gendisk *disk)
- {
- struct disk_part_tbl *ptbl;
- int i;
- bool ret = false;
- rcu_read_lock();
- ptbl = rcu_dereference(disk->part_tbl);
- /* Iterate partitions skipping the whole device at index 0 */
- for (i = 1; i < ptbl->len; i++) {
- if (rcu_dereference(ptbl->part[i])) {
- ret = true;
- break;
- }
- }
- rcu_read_unlock();
- return ret;
- }
- EXPORT_SYMBOL_GPL(disk_has_partitions);
- /*
- * Can be deleted altogether. Later.
- *
- */
- #define BLKDEV_MAJOR_HASH_SIZE 255
- 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(unsigned major)
- {
- return major % BLKDEV_MAJOR_HASH_SIZE;
- }
- #ifdef CONFIG_PROC_FS
- void blkdev_show(struct seq_file *seqf, off_t offset)
- {
- struct blk_major_name *dp;
- mutex_lock(&block_class_lock);
- 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);
- mutex_unlock(&block_class_lock);
- }
- #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
- *
- * 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.
- */
- int register_blkdev(unsigned int major, const char *name)
- {
- struct blk_major_name **n, *p;
- int index, ret = 0;
- mutex_lock(&block_class_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(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 %u for %s\n",
- major, name);
- kfree(p);
- }
- out:
- mutex_unlock(&block_class_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(&block_class_lock);
- 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;
- }
- mutex_unlock(&block_class_lock);
- kfree(p);
- }
- EXPORT_SYMBOL(unregister_blkdev);
- static struct kobj_map *bdev_map;
- /**
- * blk_mangle_minor - scatter minor numbers apart
- * @minor: minor number to mangle
- *
- * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
- * is enabled. Mangling twice gives the original value.
- *
- * RETURNS:
- * Mangled value.
- *
- * CONTEXT:
- * Don't care.
- */
- static int blk_mangle_minor(int minor)
- {
- #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
- int i;
- for (i = 0; i < MINORBITS / 2; i++) {
- int low = minor & (1 << i);
- int high = minor & (1 << (MINORBITS - 1 - i));
- int distance = MINORBITS - 1 - 2 * i;
- minor ^= low | high; /* clear both bits */
- low <<= distance; /* swap the positions */
- high >>= distance;
- minor |= low | high; /* and set */
- }
- #endif
- return minor;
- }
- /**
- * blk_alloc_devt - allocate a dev_t for a partition
- * @part: partition to allocate dev_t for
- * @devt: out parameter for resulting dev_t
- *
- * Allocate a dev_t for block device.
- *
- * RETURNS:
- * 0 on success, allocated dev_t is returned in *@devt. -errno on
- * failure.
- *
- * CONTEXT:
- * Might sleep.
- */
- int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
- {
- struct gendisk *disk = part_to_disk(part);
- int idx;
- /* in consecutive minor range? */
- if (part->partno < disk->minors) {
- *devt = MKDEV(disk->major, disk->first_minor + part->partno);
- return 0;
- }
- /* allocate ext devt */
- idr_preload(GFP_KERNEL);
- spin_lock_bh(&ext_devt_lock);
- idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_NOWAIT);
- spin_unlock_bh(&ext_devt_lock);
- idr_preload_end();
- if (idx < 0)
- return idx == -ENOSPC ? -EBUSY : idx;
- *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
- return 0;
- }
- /**
- * blk_free_devt - free a dev_t
- * @devt: dev_t to free
- *
- * Free @devt which was allocated using blk_alloc_devt().
- *
- * CONTEXT:
- * Might sleep.
- */
- void blk_free_devt(dev_t devt)
- {
- if (devt == MKDEV(0, 0))
- return;
- if (MAJOR(devt) == BLOCK_EXT_MAJOR) {
- spin_lock_bh(&ext_devt_lock);
- idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
- spin_unlock_bh(&ext_devt_lock);
- }
- }
- /*
- * We invalidate devt by assigning NULL pointer for devt in idr.
- */
- void blk_invalidate_devt(dev_t devt)
- {
- if (MAJOR(devt) == BLOCK_EXT_MAJOR) {
- spin_lock_bh(&ext_devt_lock);
- idr_replace(&ext_devt_idr, NULL, blk_mangle_minor(MINOR(devt)));
- spin_unlock_bh(&ext_devt_lock);
- }
- }
- static char *bdevt_str(dev_t devt, char *buf)
- {
- if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
- char tbuf[BDEVT_SIZE];
- snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
- snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
- } else
- snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
- return buf;
- }
- /*
- * 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 devt, unsigned long range, struct module *module,
- struct kobject *(*probe)(dev_t, int *, void *),
- int (*lock)(dev_t, void *), void *data)
- {
- kobj_map(bdev_map, devt, range, module, probe, lock, data);
- }
- EXPORT_SYMBOL(blk_register_region);
- void blk_unregister_region(dev_t devt, unsigned long range)
- {
- kobj_unmap(bdev_map, devt, range);
- }
- EXPORT_SYMBOL(blk_unregister_region);
- static struct kobject *exact_match(dev_t devt, int *partno, void *data)
- {
- struct gendisk *p = data;
- return &disk_to_dev(p)->kobj;
- }
- static int exact_lock(dev_t devt, void *data)
- {
- struct gendisk *p = data;
- if (!get_disk_and_module(p))
- return -1;
- return 0;
- }
- static void disk_scan_partitions(struct gendisk *disk)
- {
- struct block_device *bdev;
- if (!get_capacity(disk) || !disk_part_scan_enabled(disk))
- return;
- set_bit(GD_NEED_PART_SCAN, &disk->state);
- bdev = blkdev_get_by_dev(disk_devt(disk), FMODE_READ, NULL);
- if (!IS_ERR(bdev))
- blkdev_put(bdev, FMODE_READ);
- }
- static void register_disk(struct device *parent, struct gendisk *disk,
- const struct attribute_group **groups)
- {
- struct device *ddev = disk_to_dev(disk);
- struct disk_part_iter piter;
- struct hd_struct *part;
- int err;
- ddev->parent = parent;
- dev_set_name(ddev, "%s", disk->disk_name);
- /* delay uevents, until we scanned partition table */
- dev_set_uevent_suppress(ddev, 1);
- if (groups) {
- WARN_ON(ddev->groups);
- ddev->groups = groups;
- }
- if (device_add(ddev))
- return;
- if (!sysfs_deprecated) {
- err = sysfs_create_link(block_depr, &ddev->kobj,
- kobject_name(&ddev->kobj));
- if (err) {
- device_del(ddev);
- return;
- }
- }
- /*
- * 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.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
- disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
- if (disk->flags & GENHD_FL_HIDDEN)
- return;
- disk_scan_partitions(disk);
- /* announce disk after possible partitions are created */
- dev_set_uevent_suppress(ddev, 0);
- kobject_uevent(&ddev->kobj, KOBJ_ADD);
- /* announce possible partitions */
- disk_part_iter_init(&piter, disk, 0);
- while ((part = disk_part_iter_next(&piter)))
- kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
- disk_part_iter_exit(&piter);
- if (disk->queue->backing_dev_info->dev) {
- err = sysfs_create_link(&ddev->kobj,
- &disk->queue->backing_dev_info->dev->kobj,
- "bdi");
- WARN_ON(err);
- }
- }
- /**
- * __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
- * @register_queue: register the queue if set to true
- *
- * This function registers the partitioning information in @disk
- * with the kernel.
- *
- * FIXME: error handling
- */
- static void __device_add_disk(struct device *parent, struct gendisk *disk,
- const struct attribute_group **groups,
- bool register_queue)
- {
- dev_t devt;
- int retval;
- /*
- * The disk queue should now be all set with enough information about
- * the device for the elevator code to pick an adequate default
- * elevator if one is needed, that is, for devices requesting queue
- * registration.
- */
- if (register_queue)
- elevator_init_mq(disk->queue);
- /* minors == 0 indicates to use ext devt from part0 and should
- * be accompanied with EXT_DEVT flag. Make sure all
- * parameters make sense.
- */
- WARN_ON(disk->minors && !(disk->major || disk->first_minor));
- WARN_ON(!disk->minors &&
- !(disk->flags & (GENHD_FL_EXT_DEVT | GENHD_FL_HIDDEN)));
- disk->flags |= GENHD_FL_UP;
- retval = blk_alloc_devt(&disk->part0, &devt);
- if (retval) {
- WARN_ON(1);
- return;
- }
- disk->major = MAJOR(devt);
- disk->first_minor = MINOR(devt);
- disk_alloc_events(disk);
- if (disk->flags & GENHD_FL_HIDDEN) {
- /*
- * Don't let hidden disks show up in /proc/partitions,
- * and don't bother scanning for partitions either.
- */
- disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO;
- disk->flags |= GENHD_FL_NO_PART_SCAN;
- } else {
- struct backing_dev_info *bdi = disk->queue->backing_dev_info;
- struct device *dev = disk_to_dev(disk);
- int ret;
- /* Register BDI before referencing it from bdev */
- dev->devt = devt;
- ret = bdi_register(bdi, "%u:%u", MAJOR(devt), MINOR(devt));
- WARN_ON(ret);
- bdi_set_owner(bdi, dev);
- blk_register_region(disk_devt(disk), disk->minors, NULL,
- exact_match, exact_lock, disk);
- }
- register_disk(parent, disk, groups);
- if (register_queue)
- blk_register_queue(disk);
- /*
- * Take an extra ref on queue which will be put on disk_release()
- * so that it sticks around as long as @disk is there.
- */
- WARN_ON_ONCE(!blk_get_queue(disk->queue));
- disk_add_events(disk);
- blk_integrity_add(disk);
- }
- void device_add_disk(struct device *parent, struct gendisk *disk,
- const struct attribute_group **groups)
- {
- __device_add_disk(parent, disk, groups, true);
- }
- EXPORT_SYMBOL(device_add_disk);
- void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk)
- {
- __device_add_disk(parent, disk, NULL, false);
- }
- EXPORT_SYMBOL(device_add_disk_no_queue_reg);
- static void invalidate_partition(struct gendisk *disk, int partno)
- {
- struct block_device *bdev;
- bdev = bdget_disk(disk, partno);
- if (!bdev)
- return;
- fsync_bdev(bdev);
- __invalidate_device(bdev, true);
- /*
- * Unhash the bdev inode for this device so that it gets evicted as soon
- * as last inode reference is dropped.
- */
- remove_inode_hash(bdev->bd_inode);
- bdput(bdev);
- }
- /**
- * 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 disk_part_iter piter;
- struct hd_struct *part;
- might_sleep();
- blk_integrity_del(disk);
- disk_del_events(disk);
- /*
- * Block lookups of the disk until all bdevs are unhashed and the
- * disk is marked as dead (GENHD_FL_UP cleared).
- */
- down_write(&disk->lookup_sem);
- /* invalidate stuff */
- disk_part_iter_init(&piter, disk,
- DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
- while ((part = disk_part_iter_next(&piter))) {
- invalidate_partition(disk, part->partno);
- delete_partition(part);
- }
- disk_part_iter_exit(&piter);
- invalidate_partition(disk, 0);
- set_capacity(disk, 0);
- disk->flags &= ~GENHD_FL_UP;
- up_write(&disk->lookup_sem);
- if (!(disk->flags & GENHD_FL_HIDDEN))
- sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
- if (disk->queue) {
- /*
- * Unregister bdi before releasing device numbers (as they can
- * get reused and we'd get clashes in sysfs).
- */
- if (!(disk->flags & GENHD_FL_HIDDEN))
- bdi_unregister(disk->queue->backing_dev_info);
- blk_unregister_queue(disk);
- } else {
- WARN_ON(1);
- }
- if (!(disk->flags & GENHD_FL_HIDDEN))
- blk_unregister_region(disk_devt(disk), disk->minors);
- /*
- * Remove gendisk pointer from idr so that it cannot be looked up
- * while RCU period before freeing gendisk is running to prevent
- * use-after-free issues. Note that the device number stays
- * "in-use" until we really free the gendisk.
- */
- blk_invalidate_devt(disk_devt(disk));
- kobject_put(disk->part0.holder_dir);
- kobject_put(disk->slave_dir);
- part_stat_set_all(&disk->part0, 0);
- disk->part0.stamp = 0;
- if (!sysfs_deprecated)
- 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));
- }
- EXPORT_SYMBOL(del_gendisk);
- /* 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 sprintf(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);
- }
- /**
- * get_gendisk - get partitioning information for a given device
- * @devt: device to get partitioning information for
- * @partno: returned partition index
- *
- * This function gets the structure containing partitioning
- * information for the given device @devt.
- *
- * Context: can sleep
- */
- struct gendisk *get_gendisk(dev_t devt, int *partno)
- {
- struct gendisk *disk = NULL;
- might_sleep();
- if (MAJOR(devt) != BLOCK_EXT_MAJOR) {
- struct kobject *kobj;
- kobj = kobj_lookup(bdev_map, devt, partno);
- if (kobj)
- disk = dev_to_disk(kobj_to_dev(kobj));
- } else {
- struct hd_struct *part;
- spin_lock_bh(&ext_devt_lock);
- part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
- if (part && get_disk_and_module(part_to_disk(part))) {
- *partno = part->partno;
- disk = part_to_disk(part);
- }
- spin_unlock_bh(&ext_devt_lock);
- }
- if (!disk)
- return NULL;
- /*
- * Synchronize with del_gendisk() to not return disk that is being
- * destroyed.
- */
- down_read(&disk->lookup_sem);
- if (unlikely((disk->flags & GENHD_FL_HIDDEN) ||
- !(disk->flags & GENHD_FL_UP))) {
- up_read(&disk->lookup_sem);
- put_disk_and_module(disk);
- disk = NULL;
- } else {
- up_read(&disk->lookup_sem);
- }
- return disk;
- }
- /**
- * bdget_disk - do bdget() by gendisk and partition number
- * @disk: gendisk of interest
- * @partno: partition number
- *
- * Find partition @partno from @disk, do bdget() on it.
- *
- * CONTEXT:
- * Don't care.
- *
- * RETURNS:
- * Resulting block_device on success, NULL on failure.
- */
- struct block_device *bdget_disk(struct gendisk *disk, int partno)
- {
- struct hd_struct *part;
- struct block_device *bdev = NULL;
- part = disk_get_part(disk, partno);
- if (part)
- bdev = bdget_part(part);
- disk_put_part(part);
- return bdev;
- }
- EXPORT_SYMBOL(bdget_disk);
- /*
- * print a full list of all partitions - intended for places where the root
- * filesystem can't be mounted and thus to give the victim some idea of what
- * went wrong
- */
- void __init printk_all_partitions(void)
- {
- struct class_dev_iter iter;
- struct device *dev;
- class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
- while ((dev = class_dev_iter_next(&iter))) {
- struct gendisk *disk = dev_to_disk(dev);
- struct disk_part_iter piter;
- struct hd_struct *part;
- char name_buf[BDEVNAME_SIZE];
- char devt_buf[BDEVT_SIZE];
- /*
- * Don't show empty devices or things that have been
- * suppressed
- */
- if (get_capacity(disk) == 0 ||
- (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
- continue;
- /*
- * Note, unlike /proc/partitions, I am showing the
- * numbers in hex - the same format as the root=
- * option takes.
- */
- disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
- while ((part = disk_part_iter_next(&piter))) {
- bool is_part0 = part == &disk->part0;
- printk("%s%s %10llu %s %s", is_part0 ? "" : " ",
- bdevt_str(part_devt(part), devt_buf),
- (unsigned long long)part_nr_sects_read(part) >> 1
- , disk_name(disk, part->partno, name_buf),
- part->info ? part->info->uuid : "");
- if (is_part0) {
- if (dev->parent && dev->parent->driver)
- printk(" driver: %s\n",
- dev->parent->driver->name);
- else
- printk(" (driver?)\n");
- } else
- printk("\n");
- }
- disk_part_iter_exit(&piter);
- }
- class_dev_iter_exit(&iter);
- }
- #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(sizeof(*iter), GFP_KERNEL);
- 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 disk_part_iter piter;
- struct hd_struct *part;
- char buf[BDEVNAME_SIZE];
- /* Don't show non-partitionable removeable devices or empty devices */
- if (!get_capacity(sgp) || (!disk_max_parts(sgp) &&
- (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 */
- disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
- while ((part = disk_part_iter_next(&piter)))
- seq_printf(seqf, "%4d %7d %10llu %s\n",
- MAJOR(part_devt(part)), MINOR(part_devt(part)),
- (unsigned long long)part_nr_sects_read(part) >> 1,
- disk_name(sgp, part->partno, buf));
- disk_part_iter_exit(&piter);
- 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 struct kobject *base_probe(dev_t devt, int *partno, void *data)
- {
- if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
- /* Make old-style 2.4 aliases work */
- request_module("block-major-%d", MAJOR(devt));
- return NULL;
- }
- static int __init genhd_device_init(void)
- {
- int error;
- block_class.dev_kobj = sysfs_dev_block_kobj;
- error = class_register(&block_class);
- if (unlikely(error))
- return error;
- bdev_map = kobj_map_init(base_probe, &block_class_lock);
- blk_dev_init();
- register_blkdev(BLOCK_EXT_MAJOR, "blkext");
- /* create top-level block dir */
- if (!sysfs_deprecated)
- 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 sprintf(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 sprintf(buf, "%d\n", disk_max_parts(disk));
- }
- static ssize_t disk_removable_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- struct gendisk *disk = dev_to_disk(dev);
- return sprintf(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 sprintf(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 sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
- }
- ssize_t part_size_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- struct hd_struct *p = dev_to_part(dev);
- return sprintf(buf, "%llu\n",
- (unsigned long long)part_nr_sects_read(p));
- }
- ssize_t part_stat_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- struct hd_struct *p = dev_to_part(dev);
- struct request_queue *q = part_to_disk(p)->queue;
- struct disk_stats stat;
- unsigned int inflight;
- part_stat_read_all(p, &stat);
- if (queue_is_mq(q))
- inflight = blk_mq_in_flight(q, p);
- else
- inflight = part_in_flight(p);
- return sprintf(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));
- }
- ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
- char *buf)
- {
- struct hd_struct *p = dev_to_part(dev);
- struct request_queue *q = part_to_disk(p)->queue;
- unsigned int inflight[2];
- if (queue_is_mq(q))
- blk_mq_in_flight_rw(q, p, inflight);
- else
- part_in_flight_rw(p, inflight);
- return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]);
- }
- static ssize_t disk_capability_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- struct gendisk *disk = dev_to_disk(dev);
- return sprintf(buf, "%x\n", disk->flags);
- }
- static ssize_t disk_alignment_offset_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
- {
- struct gendisk *disk = dev_to_disk(dev);
- return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue));
- }
- static ssize_t disk_discard_alignment_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
- {
- struct gendisk *disk = dev_to_disk(dev);
- return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue));
- }
- 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);
- #ifdef CONFIG_FAIL_MAKE_REQUEST
- ssize_t part_fail_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- struct hd_struct *p = dev_to_part(dev);
- return sprintf(buf, "%d\n", p->make_it_fail);
- }
- ssize_t part_fail_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
- {
- struct hd_struct *p = dev_to_part(dev);
- int i;
- if (count > 0 && sscanf(buf, "%d", &i) > 0)
- p->make_it_fail = (i == 0) ? 0 : 1;
- 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_TIMEOUT
- static 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,
- #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,
- NULL
- };
- /**
- * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
- * @disk: disk to replace part_tbl for
- * @new_ptbl: new part_tbl to install
- *
- * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The
- * original ptbl is freed using RCU callback.
- *
- * LOCKING:
- * Matching bd_mutex locked or the caller is the only user of @disk.
- */
- static void disk_replace_part_tbl(struct gendisk *disk,
- struct disk_part_tbl *new_ptbl)
- {
- struct disk_part_tbl *old_ptbl =
- rcu_dereference_protected(disk->part_tbl, 1);
- rcu_assign_pointer(disk->part_tbl, new_ptbl);
- if (old_ptbl) {
- rcu_assign_pointer(old_ptbl->last_lookup, NULL);
- kfree_rcu(old_ptbl, rcu_head);
- }
- }
- /**
- * disk_expand_part_tbl - expand disk->part_tbl
- * @disk: disk to expand part_tbl for
- * @partno: expand such that this partno can fit in
- *
- * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl
- * uses RCU to allow unlocked dereferencing for stats and other stuff.
- *
- * LOCKING:
- * Matching bd_mutex locked or the caller is the only user of @disk.
- * Might sleep.
- *
- * RETURNS:
- * 0 on success, -errno on failure.
- */
- int disk_expand_part_tbl(struct gendisk *disk, int partno)
- {
- struct disk_part_tbl *old_ptbl =
- rcu_dereference_protected(disk->part_tbl, 1);
- struct disk_part_tbl *new_ptbl;
- int len = old_ptbl ? old_ptbl->len : 0;
- int i, target;
- /*
- * check for int overflow, since we can get here from blkpg_ioctl()
- * with a user passed 'partno'.
- */
- target = partno + 1;
- if (target < 0)
- return -EINVAL;
- /* disk_max_parts() is zero during initialization, ignore if so */
- if (disk_max_parts(disk) && target > disk_max_parts(disk))
- return -EINVAL;
- if (target <= len)
- return 0;
- new_ptbl = kzalloc_node(struct_size(new_ptbl, part, target), GFP_KERNEL,
- disk->node_id);
- if (!new_ptbl)
- return -ENOMEM;
- new_ptbl->len = target;
- for (i = 0; i < len; i++)
- rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]);
- disk_replace_part_tbl(disk, new_ptbl);
- return 0;
- }
- /**
- * disk_release - releases all allocated resources of the gendisk
- * @dev: the device representing this disk
- *
- * This function releases all allocated resources of the gendisk.
- *
- * The struct gendisk refcount is incremented with get_gendisk() or
- * get_disk_and_module(), and its refcount is decremented with
- * put_disk_and_module() or put_disk(). Once the refcount reaches 0 this
- * function is called.
- *
- * 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();
- blk_free_devt(dev->devt);
- disk_release_events(disk);
- kfree(disk->random);
- disk_replace_part_tbl(disk, NULL);
- hd_free_part(&disk->part0);
- if (disk->queue)
- blk_put_queue(disk->queue);
- kfree(disk);
- }
- struct class block_class = {
- .name = "block",
- };
- static char *block_devnode(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 disk_part_iter piter;
- struct hd_struct *hd;
- char buf[BDEVNAME_SIZE];
- unsigned int inflight;
- struct disk_stats stat;
- /*
- 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");
- */
- disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
- while ((hd = disk_part_iter_next(&piter))) {
- part_stat_read_all(hd, &stat);
- if (queue_is_mq(gp->queue))
- inflight = blk_mq_in_flight(gp->queue, hd);
- else
- inflight = part_in_flight(hd);
- seq_printf(seqf, "%4d %7d %s "
- "%lu %lu %lu %u "
- "%lu %lu %lu %u "
- "%u %u %u "
- "%lu %lu %lu %u "
- "%lu %u"
- "\n",
- MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
- disk_name(gp, hd->partno, buf),
- stat.ios[STAT_READ],
- stat.merges[STAT_READ],
- stat.sectors[STAT_READ],
- (unsigned int)div_u64(stat.nsecs[STAT_READ],
- NSEC_PER_MSEC),
- stat.ios[STAT_WRITE],
- stat.merges[STAT_WRITE],
- 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],
- 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)
- );
- }
- disk_part_iter_exit(&piter);
- 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 blk_lookup_devt(const char *name, int partno)
- {
- dev_t devt = MKDEV(0, 0);
- struct class_dev_iter iter;
- struct device *dev;
- class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
- while ((dev = class_dev_iter_next(&iter))) {
- struct gendisk *disk = dev_to_disk(dev);
- struct hd_struct *part;
- if (strcmp(dev_name(dev), name))
- continue;
- if (partno < disk->minors) {
- /* We need to return the right devno, even
- * if the partition doesn't exist yet.
- */
- devt = MKDEV(MAJOR(dev->devt),
- MINOR(dev->devt) + partno);
- break;
- }
- part = disk_get_part(disk, partno);
- if (part) {
- devt = part_devt(part);
- disk_put_part(part);
- break;
- }
- disk_put_part(part);
- }
- class_dev_iter_exit(&iter);
- return devt;
- }
- struct gendisk *__alloc_disk_node(int minors, int node_id)
- {
- struct gendisk *disk;
- struct disk_part_tbl *ptbl;
- if (minors > DISK_MAX_PARTS) {
- printk(KERN_ERR
- "block: can't allocate more than %d partitions\n",
- DISK_MAX_PARTS);
- minors = DISK_MAX_PARTS;
- }
- disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
- if (!disk)
- return NULL;
- disk->part0.dkstats = alloc_percpu(struct disk_stats);
- if (!disk->part0.dkstats)
- goto out_free_disk;
- init_rwsem(&disk->lookup_sem);
- disk->node_id = node_id;
- if (disk_expand_part_tbl(disk, 0)) {
- free_percpu(disk->part0.dkstats);
- goto out_free_disk;
- }
- ptbl = rcu_dereference_protected(disk->part_tbl, 1);
- rcu_assign_pointer(ptbl->part[0], &disk->part0);
- /*
- * set_capacity() and get_capacity() currently don't use
- * seqcounter to read/update the part0->nr_sects. Still init
- * the counter as we can read the sectors in IO submission
- * patch using seqence counters.
- *
- * TODO: Ideally set_capacity() and get_capacity() should be
- * converted to make use of bd_mutex and sequence counters.
- */
- hd_sects_seq_init(&disk->part0);
- if (hd_ref_init(&disk->part0))
- goto out_free_part0;
- disk->minors = minors;
- rand_initialize_disk(disk);
- disk_to_dev(disk)->class = &block_class;
- disk_to_dev(disk)->type = &disk_type;
- device_initialize(disk_to_dev(disk));
- return disk;
- out_free_part0:
- hd_free_part(&disk->part0);
- out_free_disk:
- kfree(disk);
- return NULL;
- }
- EXPORT_SYMBOL(__alloc_disk_node);
- /**
- * get_disk_and_module - increments the gendisk and gendisk fops module refcount
- * @disk: the struct gendisk to increment the refcount for
- *
- * This increments the refcount for the struct gendisk, and the gendisk's
- * fops module owner.
- *
- * Context: Any context.
- */
- struct kobject *get_disk_and_module(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_unless_zero(&disk_to_dev(disk)->kobj);
- if (kobj == NULL) {
- module_put(owner);
- return NULL;
- }
- return kobj;
- }
- EXPORT_SYMBOL(get_disk_and_module);
- /**
- * 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.
- *
- * Context: Any context, but the last reference must not be dropped from
- * atomic context.
- */
- void put_disk(struct gendisk *disk)
- {
- if (disk)
- kobject_put(&disk_to_dev(disk)->kobj);
- }
- EXPORT_SYMBOL(put_disk);
- /**
- * put_disk_and_module - decrements the module and gendisk refcount
- * @disk: the struct gendisk to decrement the refcount for
- *
- * This is a counterpart of get_disk_and_module() and thus also of
- * get_gendisk().
- *
- * Context: Any context, but the last reference must not be dropped from
- * atomic context.
- */
- void put_disk_and_module(struct gendisk *disk)
- {
- if (disk) {
- struct module *owner = disk->fops->owner;
- put_disk(disk);
- module_put(owner);
- }
- }
- EXPORT_SYMBOL(put_disk_and_module);
- 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);
- }
- void set_device_ro(struct block_device *bdev, int flag)
- {
- bdev->bd_part->policy = flag;
- }
- EXPORT_SYMBOL(set_device_ro);
- void set_disk_ro(struct gendisk *disk, int flag)
- {
- struct disk_part_iter piter;
- struct hd_struct *part;
- if (disk->part0.policy != flag) {
- set_disk_ro_uevent(disk, flag);
- disk->part0.policy = flag;
- }
- disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
- while ((part = disk_part_iter_next(&piter)))
- part->policy = flag;
- disk_part_iter_exit(&piter);
- }
- EXPORT_SYMBOL(set_disk_ro);
- int bdev_read_only(struct block_device *bdev)
- {
- if (!bdev)
- return 0;
- return bdev->bd_part->policy;
- }
- EXPORT_SYMBOL(bdev_read_only);
- /*
- * Disk events - monitor disk events like media change and eject request.
- */
- struct disk_events {
- struct list_head node; /* all disk_event's */
- struct gendisk *disk; /* the associated disk */
- spinlock_t lock;
- struct mutex block_mutex; /* protects blocking */
- int block; /* event blocking depth */
- unsigned int pending; /* events already sent out */
- unsigned int clearing; /* events being cleared */
- long poll_msecs; /* interval, -1 for default */
- struct delayed_work dwork;
- };
- static const char *disk_events_strs[] = {
- [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change",
- [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request",
- };
- static char *disk_uevents[] = {
- [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1",
- [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1",
- };
- /* list of all disk_events */
- static DEFINE_MUTEX(disk_events_mutex);
- static LIST_HEAD(disk_events);
- /* disable in-kernel polling by default */
- static unsigned long disk_events_dfl_poll_msecs;
- static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
- {
- struct disk_events *ev = disk->ev;
- long intv_msecs = 0;
- /*
- * If device-specific poll interval is set, always use it. If
- * the default is being used, poll if the POLL flag is set.
- */
- if (ev->poll_msecs >= 0)
- intv_msecs = ev->poll_msecs;
- else if (disk->event_flags & DISK_EVENT_FLAG_POLL)
- intv_msecs = disk_events_dfl_poll_msecs;
- return msecs_to_jiffies(intv_msecs);
- }
- /**
- * disk_block_events - block and flush disk event checking
- * @disk: disk to block events for
- *
- * On return from this function, it is guaranteed that event checking
- * isn't in progress and won't happen until unblocked by
- * disk_unblock_events(). Events blocking is counted and the actual
- * unblocking happens after the matching number of unblocks are done.
- *
- * Note that this intentionally does not block event checking from
- * disk_clear_events().
- *
- * CONTEXT:
- * Might sleep.
- */
- void disk_block_events(struct gendisk *disk)
- {
- struct disk_events *ev = disk->ev;
- unsigned long flags;
- bool cancel;
- if (!ev)
- return;
- /*
- * Outer mutex ensures that the first blocker completes canceling
- * the event work before further blockers are allowed to finish.
- */
- mutex_lock(&ev->block_mutex);
- spin_lock_irqsave(&ev->lock, flags);
- cancel = !ev->block++;
- spin_unlock_irqrestore(&ev->lock, flags);
- if (cancel)
- cancel_delayed_work_sync(&disk->ev->dwork);
- mutex_unlock(&ev->block_mutex);
- }
- static void __disk_unblock_events(struct gendisk *disk, bool check_now)
- {
- struct disk_events *ev = disk->ev;
- unsigned long intv;
- unsigned long flags;
- spin_lock_irqsave(&ev->lock, flags);
- if (WARN_ON_ONCE(ev->block <= 0))
- goto out_unlock;
- if (--ev->block)
- goto out_unlock;
- intv = disk_events_poll_jiffies(disk);
- if (check_now)
- queue_delayed_work(system_freezable_power_efficient_wq,
- &ev->dwork, 0);
- else if (intv)
- queue_delayed_work(system_freezable_power_efficient_wq,
- &ev->dwork, intv);
- out_unlock:
- spin_unlock_irqrestore(&ev->lock, flags);
- }
- /**
- * disk_unblock_events - unblock disk event checking
- * @disk: disk to unblock events for
- *
- * Undo disk_block_events(). When the block count reaches zero, it
- * starts events polling if configured.
- *
- * CONTEXT:
- * Don't care. Safe to call from irq context.
- */
- void disk_unblock_events(struct gendisk *disk)
- {
- if (disk->ev)
- __disk_unblock_events(disk, false);
- }
- /**
- * disk_flush_events - schedule immediate event checking and flushing
- * @disk: disk to check and flush events for
- * @mask: events to flush
- *
- * Schedule immediate event checking on @disk if not blocked. Events in
- * @mask are scheduled to be cleared from the driver. Note that this
- * doesn't clear the events from @disk->ev.
- *
- * CONTEXT:
- * If @mask is non-zero must be called with bdev->bd_mutex held.
- */
- void disk_flush_events(struct gendisk *disk, unsigned int mask)
- {
- struct disk_events *ev = disk->ev;
- if (!ev)
- return;
- spin_lock_irq(&ev->lock);
- ev->clearing |= mask;
- if (!ev->block)
- mod_delayed_work(system_freezable_power_efficient_wq,
- &ev->dwork, 0);
- spin_unlock_irq(&ev->lock);
- }
- /**
- * disk_clear_events - synchronously check, clear and return pending events
- * @disk: disk to fetch and clear events from
- * @mask: mask of events to be fetched and cleared
- *
- * Disk events are synchronously checked and pending events in @mask
- * are cleared and returned. This ignores the block count.
- *
- * CONTEXT:
- * Might sleep.
- */
- static unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
- {
- struct disk_events *ev = disk->ev;
- unsigned int pending;
- unsigned int clearing = mask;
- if (!ev)
- return 0;
- disk_block_events(disk);
- /*
- * store the union of mask and ev->clearing on the stack so that the
- * race with disk_flush_events does not cause ambiguity (ev->clearing
- * can still be modified even if events are blocked).
- */
- spin_lock_irq(&ev->lock);
- clearing |= ev->clearing;
- ev->clearing = 0;
- spin_unlock_irq(&ev->lock);
- disk_check_events(ev, &clearing);
- /*
- * if ev->clearing is not 0, the disk_flush_events got called in the
- * middle of this function, so we want to run the workfn without delay.
- */
- __disk_unblock_events(disk, ev->clearing ? true : false);
- /* then, fetch and clear pending events */
- spin_lock_irq(&ev->lock);
- pending = ev->pending & mask;
- ev->pending &= ~mask;
- spin_unlock_irq(&ev->lock);
- WARN_ON_ONCE(clearing & mask);
- return pending;
- }
- /**
- * bdev_check_media_change - check if a removable media has been changed
- * @bdev: block device to check
- *
- * Check whether a removable media has been changed, and attempt to free all
- * dentries and inodes and invalidates all block device page cache entries in
- * that case.
- *
- * Returns %true if the block device changed, or %false if not.
- */
- bool bdev_check_media_change(struct block_device *bdev)
- {
- unsigned int events;
- events = disk_clear_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE |
- DISK_EVENT_EJECT_REQUEST);
- if (!(events & DISK_EVENT_MEDIA_CHANGE))
- return false;
- if (__invalidate_device(bdev, true))
- pr_warn("VFS: busy inodes on changed media %s\n",
- bdev->bd_disk->disk_name);
- set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
- return true;
- }
- EXPORT_SYMBOL(bdev_check_media_change);
- /*
- * Separate this part out so that a different pointer for clearing_ptr can be
- * passed in for disk_clear_events.
- */
- static void disk_events_workfn(struct work_struct *work)
- {
- struct delayed_work *dwork = to_delayed_work(work);
- struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
- disk_check_events(ev, &ev->clearing);
- }
- static void disk_check_events(struct disk_events *ev,
- unsigned int *clearing_ptr)
- {
- struct gendisk *disk = ev->disk;
- char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
- unsigned int clearing = *clearing_ptr;
- unsigned int events;
- unsigned long intv;
- int nr_events = 0, i;
- /* check events */
- events = disk->fops->check_events(disk, clearing);
- /* accumulate pending events and schedule next poll if necessary */
- spin_lock_irq(&ev->lock);
- events &= ~ev->pending;
- ev->pending |= events;
- *clearing_ptr &= ~clearing;
- intv = disk_events_poll_jiffies(disk);
- if (!ev->block && intv)
- queue_delayed_work(system_freezable_power_efficient_wq,
- &ev->dwork, intv);
- spin_unlock_irq(&ev->lock);
- /*
- * Tell userland about new events. Only the events listed in
- * @disk->events are reported, and only if DISK_EVENT_FLAG_UEVENT
- * is set. Otherwise, events are processed internally but never
- * get reported to userland.
- */
- for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
- if ((events & disk->events & (1 << i)) &&
- (disk->event_flags & DISK_EVENT_FLAG_UEVENT))
- envp[nr_events++] = disk_uevents[i];
- if (nr_events)
- kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
- }
- /*
- * A disk events enabled device has the following sysfs nodes under
- * its /sys/block/X/ directory.
- *
- * events : list of all supported events
- * events_async : list of events which can be detected w/o polling
- * (always empty, only for backwards compatibility)
- * events_poll_msecs : polling interval, 0: disable, -1: system default
- */
- static ssize_t __disk_events_show(unsigned int events, char *buf)
- {
- const char *delim = "";
- ssize_t pos = 0;
- int i;
- for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++)
- if (events & (1 << i)) {
- pos += sprintf(buf + pos, "%s%s",
- delim, disk_events_strs[i]);
- delim = " ";
- }
- if (pos)
- pos += sprintf(buf + pos, "\n");
- return pos;
- }
- static ssize_t disk_events_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- struct gendisk *disk = dev_to_disk(dev);
- if (!(disk->event_flags & DISK_EVENT_FLAG_UEVENT))
- return 0;
- return __disk_events_show(disk->events, buf);
- }
- static ssize_t disk_events_async_show(struct device *dev,
- struct device_attribute *attr, char *buf)
- {
- return 0;
- }
- static ssize_t disk_events_poll_msecs_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
- {
- struct gendisk *disk = dev_to_disk(dev);
- if (!disk->ev)
- return sprintf(buf, "-1\n");
- return sprintf(buf, "%ld\n", disk->ev->poll_msecs);
- }
- static ssize_t disk_events_poll_msecs_store(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t count)
- {
- struct gendisk *disk = dev_to_disk(dev);
- long intv;
- if (!count || !sscanf(buf, "%ld", &intv))
- return -EINVAL;
- if (intv < 0 && intv != -1)
- return -EINVAL;
- if (!disk->ev)
- return -ENODEV;
- disk_block_events(disk);
- disk->ev->poll_msecs = intv;
- __disk_unblock_events(disk, true);
- return count;
- }
- static const DEVICE_ATTR(events, 0444, disk_events_show, NULL);
- static const DEVICE_ATTR(events_async, 0444, disk_events_async_show, NULL);
- static const DEVICE_ATTR(events_poll_msecs, 0644,
- disk_events_poll_msecs_show,
- disk_events_poll_msecs_store);
- static const struct attribute *disk_events_attrs[] = {
- &dev_attr_events.attr,
- &dev_attr_events_async.attr,
- &dev_attr_events_poll_msecs.attr,
- NULL,
- };
- /*
- * The default polling interval can be specified by the kernel
- * parameter block.events_dfl_poll_msecs which defaults to 0
- * (disable). This can also be modified runtime by writing to
- * /sys/module/block/parameters/events_dfl_poll_msecs.
- */
- static int disk_events_set_dfl_poll_msecs(const char *val,
- const struct kernel_param *kp)
- {
- struct disk_events *ev;
- int ret;
- ret = param_set_ulong(val, kp);
- if (ret < 0)
- return ret;
- mutex_lock(&disk_events_mutex);
- list_for_each_entry(ev, &disk_events, node)
- disk_flush_events(ev->disk, 0);
- mutex_unlock(&disk_events_mutex);
- return 0;
- }
- static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = {
- .set = disk_events_set_dfl_poll_msecs,
- .get = param_get_ulong,
- };
- #undef MODULE_PARAM_PREFIX
- #define MODULE_PARAM_PREFIX "block."
- module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
- &disk_events_dfl_poll_msecs, 0644);
- /*
- * disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
- */
- static void disk_alloc_events(struct gendisk *disk)
- {
- struct disk_events *ev;
- if (!disk->fops->check_events || !disk->events)
- return;
- ev = kzalloc(sizeof(*ev), GFP_KERNEL);
- if (!ev) {
- pr_warn("%s: failed to initialize events\n", disk->disk_name);
- return;
- }
- INIT_LIST_HEAD(&ev->node);
- ev->disk = disk;
- spin_lock_init(&ev->lock);
- mutex_init(&ev->block_mutex);
- ev->block = 1;
- ev->poll_msecs = -1;
- INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
- disk->ev = ev;
- }
- static void disk_add_events(struct gendisk *disk)
- {
- /* FIXME: error handling */
- if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0)
- pr_warn("%s: failed to create sysfs files for events\n",
- disk->disk_name);
- if (!disk->ev)
- return;
- mutex_lock(&disk_events_mutex);
- list_add_tail(&disk->ev->node, &disk_events);
- mutex_unlock(&disk_events_mutex);
- /*
- * Block count is initialized to 1 and the following initial
- * unblock kicks it into action.
- */
- __disk_unblock_events(disk, true);
- }
- static void disk_del_events(struct gendisk *disk)
- {
- if (disk->ev) {
- disk_block_events(disk);
- mutex_lock(&disk_events_mutex);
- list_del_init(&disk->ev->node);
- mutex_unlock(&disk_events_mutex);
- }
- sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
- }
- static void disk_release_events(struct gendisk *disk)
- {
- /* the block count should be 1 from disk_del_events() */
- WARN_ON_ONCE(disk->ev && disk->ev->block != 1);
- kfree(disk->ev);
- }
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