| // 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 |
| */ |
| void 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); |
| } |
| } |
| |
| 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_part->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; |
| if (!part_nr_sects_read(part) && |
| !(piter->flags & DISK_PITER_INCL_EMPTY) && |
| !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && |
| piter->idx == 0)) |
| continue; |
| |
| get_device(part_to_dev(part)); |
| piter->part = part; |
| 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) { |
| dev_set_uevent_suppress(ddev, 0); |
| 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_devt(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); |
| } |