linux/block/genhd.c
Daniel Wagner 9ec491447b block: Suppress uevent for hidden device when removed
register_disk() suppress uevents for devices with the GENHD_FL_HIDDEN
but enables uevents at the end again in order to announce disk after
possible partitions are created.

When the device is removed the uevents are still on and user land sees
'remove' messages for devices which were never 'add'ed to the system.

  KERNEL[95481.571887] remove   /devices/virtual/nvme-fabrics/ctl/nvme5/nvme0c5n1 (block)

Let's suppress the uevents for GENHD_FL_HIDDEN by not enabling the
uevents at all.

Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin Wilck <mwilck@suse.com>
Link: https://lore.kernel.org/r/20210311151917.136091-1-dwagner@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-03-11 11:48:25 -07:00

1941 lines
48 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* gendisk handling
*
* Portions Copyright (C) 2020 Christoph Hellwig
*/
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/fs.h>
#include <linux/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/mutex.h>
#include <linux/idr.h>
#include <linux/log2.h>
#include <linux/pm_runtime.h>
#include <linux/badblocks.h>
#include "blk.h"
static struct kobject *block_depr;
DECLARE_RWSEM(bdev_lookup_sem);
/* for extended dynamic devt allocation, currently only one major is used */
#define NR_EXT_DEVT (1 << MINORBITS)
static DEFINE_IDA(ext_devt_ida);
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);
void set_capacity(struct gendisk *disk, sector_t sectors)
{
struct block_device *bdev = disk->part0;
spin_lock(&bdev->bd_size_lock);
i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
spin_unlock(&bdev->bd_size_lock);
}
EXPORT_SYMBOL(set_capacity);
/*
* Set disk capacity and notify if the size is not currently zero and will not
* be set to zero. Returns true if a uevent was sent, otherwise false.
*/
bool set_capacity_and_notify(struct gendisk *disk, sector_t size)
{
sector_t capacity = get_capacity(disk);
char *envp[] = { "RESIZE=1", NULL };
set_capacity(disk, size);
/*
* Only print a message and send a uevent if the gendisk is user visible
* and alive. This avoids spamming the log and udev when setting the
* initial capacity during probing.
*/
if (size == capacity ||
(disk->flags & (GENHD_FL_UP | GENHD_FL_HIDDEN)) != GENHD_FL_UP)
return false;
pr_info("%s: detected capacity change from %lld to %lld\n",
disk->disk_name, capacity, size);
/*
* Historically we did not send a uevent for changes to/from an empty
* device.
*/
if (!capacity || !size)
return false;
kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
return true;
}
EXPORT_SYMBOL_GPL(set_capacity_and_notify);
/*
* 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 block_device *part,
struct disk_stats *stat)
{
int cpu;
memset(stat, 0, sizeof(struct disk_stats));
for_each_possible_cpu(cpu) {
struct disk_stats *ptr = per_cpu_ptr(part->bd_stats, cpu);
int group;
for (group = 0; group < NR_STAT_GROUPS; group++) {
stat->nsecs[group] += ptr->nsecs[group];
stat->sectors[group] += ptr->sectors[group];
stat->ios[group] += ptr->ios[group];
stat->merges[group] += ptr->merges[group];
}
stat->io_ticks += ptr->io_ticks;
}
}
static unsigned int part_in_flight(struct block_device *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 block_device *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;
}
/**
* 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)
{
piter->disk = disk;
piter->part = NULL;
if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0))
piter->idx = 0;
else
piter->idx = 1;
piter->flags = flags;
}
/**
* 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 block_device *disk_part_iter_next(struct disk_part_iter *piter)
{
struct block_device *part;
unsigned long idx;
/* put the last partition */
disk_part_iter_exit(piter);
rcu_read_lock();
xa_for_each_start(&piter->disk->part_tbl, idx, part, piter->idx) {
if (!bdev_nr_sectors(part) &&
!(piter->flags & DISK_PITER_INCL_EMPTY) &&
!(piter->flags & DISK_PITER_INCL_EMPTY_PART0 &&
piter->idx == 0))
continue;
piter->part = bdgrab(part);
if (!piter->part)
continue;
piter->idx = idx + 1;
break;
}
rcu_read_unlock();
return piter->part;
}
/**
* 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)
{
if (piter->part)
bdput(piter->part);
piter->part = NULL;
}
/*
* 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];
void (*probe)(dev_t devt);
} *major_names[BLKDEV_MAJOR_HASH_SIZE];
static DEFINE_MUTEX(major_names_lock);
/* 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(&major_names_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(&major_names_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
* @probe: allback that is called on access to any minor number of @major
*
* The @name must be unique within the system.
*
* The return value depends on the @major input parameter:
*
* - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
* then the function returns zero on success, or a negative error code
* - if any unused major number was requested with @major = 0 parameter
* then the return value is the allocated major number in range
* [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
*
* See Documentation/admin-guide/devices.txt for the list of allocated
* major numbers.
*
* Use register_blkdev instead for any new code.
*/
int __register_blkdev(unsigned int major, const char *name,
void (*probe)(dev_t devt))
{
struct blk_major_name **n, *p;
int index, ret = 0;
mutex_lock(&major_names_lock);
/* temporary */
if (major == 0) {
for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
if (major_names[index] == NULL)
break;
}
if (index == 0) {
printk("%s: failed to get major for %s\n",
__func__, name);
ret = -EBUSY;
goto out;
}
major = index;
ret = major;
}
if (major >= BLKDEV_MAJOR_MAX) {
pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
__func__, major, BLKDEV_MAJOR_MAX-1, name);
ret = -EINVAL;
goto out;
}
p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
if (p == NULL) {
ret = -ENOMEM;
goto out;
}
p->major = major;
p->probe = probe;
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(&major_names_lock);
return ret;
}
EXPORT_SYMBOL(__register_blkdev);
void unregister_blkdev(unsigned int major, const char *name)
{
struct blk_major_name **n;
struct blk_major_name *p = NULL;
int index = major_to_index(major);
mutex_lock(&major_names_lock);
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(&major_names_lock);
kfree(p);
}
EXPORT_SYMBOL(unregister_blkdev);
/**
* 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 block device
* @bdev: block device 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 block_device *bdev, dev_t *devt)
{
struct gendisk *disk = bdev->bd_disk;
int idx;
/* in consecutive minor range? */
if (bdev->bd_partno < disk->minors) {
*devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno);
return 0;
}
idx = ida_alloc_range(&ext_devt_ida, 0, NR_EXT_DEVT, GFP_KERNEL);
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 (MAJOR(devt) == BLOCK_EXT_MAJOR)
ida_free(&ext_devt_ida, blk_mangle_minor(MINOR(devt)));
}
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;
}
void disk_uevent(struct gendisk *disk, enum kobject_action action)
{
struct disk_part_iter piter;
struct block_device *part;
disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY_PART0);
while ((part = disk_part_iter_next(&piter)))
kobject_uevent(bdev_kobj(part), action);
disk_part_iter_exit(&piter);
}
EXPORT_SYMBOL_GPL(disk_uevent);
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);
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->bd_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 the disk and partitions after all partitions are created */
dev_set_uevent_suppress(ddev, 0);
disk_uevent(disk, KOBJ_ADD);
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);
bdev_add(disk->part0, devt);
}
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 block_device *bdev)
{
fsync_bdev(bdev);
__invalidate_device(bdev, true);
/*
* Unhash the bdev inode for this device so that it can't be looked
* up any more even if openers still hold references to it.
*/
remove_inode_hash(bdev->bd_inode);
}
/**
* 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 block_device *part;
might_sleep();
if (WARN_ON_ONCE(!disk->queue))
return;
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(&bdev_lookup_sem);
/* invalidate stuff */
disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
while ((part = disk_part_iter_next(&piter))) {
invalidate_partition(part);
delete_partition(part);
}
disk_part_iter_exit(&piter);
invalidate_partition(disk->part0);
set_capacity(disk, 0);
disk->flags &= ~GENHD_FL_UP;
up_write(&bdev_lookup_sem);
if (!(disk->flags & GENHD_FL_HIDDEN)) {
sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
/*
* Unregister bdi before releasing device numbers (as they can
* get reused and we'd get clashes in sysfs).
*/
bdi_unregister(disk->queue->backing_dev_info);
}
blk_unregister_queue(disk);
kobject_put(disk->part0->bd_holder_dir);
kobject_put(disk->slave_dir);
part_stat_set_all(disk->part0, 0);
disk->part0->bd_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);
}
void blk_request_module(dev_t devt)
{
unsigned int major = MAJOR(devt);
struct blk_major_name **n;
mutex_lock(&major_names_lock);
for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) {
if ((*n)->major == major && (*n)->probe) {
(*n)->probe(devt);
mutex_unlock(&major_names_lock);
return;
}
}
mutex_unlock(&major_names_lock);
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));
}
/**
* 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 block_device *bdev = NULL;
rcu_read_lock();
bdev = xa_load(&disk->part_tbl, partno);
if (bdev && !bdgrab(bdev))
bdev = NULL;
rcu_read_unlock();
return bdev;
}
/*
* 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 block_device *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->bd_dev, devt_buf),
bdev_nr_sectors(part) >> 1,
disk_name(disk, part->bd_partno, name_buf),
part->bd_meta_info ?
part->bd_meta_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 block_device *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->bd_dev), MINOR(part->bd_dev),
bdev_nr_sectors(part) >> 1,
disk_name(sgp, part->bd_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 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;
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)
{
return sprintf(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev)));
}
ssize_t part_stat_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct block_device *bdev = dev_to_bdev(dev);
struct request_queue *q = bdev->bd_disk->queue;
struct disk_stats stat;
unsigned int inflight;
part_stat_read_all(bdev, &stat);
if (queue_is_mq(q))
inflight = blk_mq_in_flight(q, bdev);
else
inflight = part_in_flight(bdev);
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 block_device *bdev = dev_to_bdev(dev);
struct request_queue *q = bdev->bd_disk->queue;
unsigned int inflight[2];
if (queue_is_mq(q))
blk_mq_in_flight_rw(q, bdev, inflight);
else
part_in_flight_rw(bdev, 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)
{
return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_make_it_fail);
}
ssize_t part_fail_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
int i;
if (count > 0 && sscanf(buf, "%d", &i) > 0)
dev_to_bdev(dev)->bd_make_it_fail = i;
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_release - releases all allocated resources of the gendisk
* @dev: the device representing this disk
*
* This function releases all allocated resources of the gendisk.
*
* Drivers which used __device_add_disk() have a gendisk with a request_queue
* assigned. Since the request_queue sits on top of the gendisk for these
* drivers we also call blk_put_queue() for them, and we expect the
* request_queue refcount to reach 0 at this point, and so the request_queue
* will also be freed prior to the disk.
*
* Context: can sleep
*/
static void disk_release(struct device *dev)
{
struct gendisk *disk = dev_to_disk(dev);
might_sleep();
blk_free_devt(dev->devt);
disk_release_events(disk);
kfree(disk->random);
xa_destroy(&disk->part_tbl);
bdput(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 block_device *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(hd->bd_dev), MINOR(hd->bd_dev),
disk_name(gp, hd->bd_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 block_device *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 = bdget_disk(disk, partno);
if (part) {
devt = part->bd_dev;
bdput(part);
break;
}
}
class_dev_iter_exit(&iter);
return devt;
}
struct gendisk *__alloc_disk_node(int minors, int node_id)
{
struct gendisk *disk;
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 = bdev_alloc(disk, 0);
if (!disk->part0)
goto out_free_disk;
disk->node_id = node_id;
xa_init(&disk->part_tbl);
if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL))
goto out_destroy_part_tbl;
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_destroy_part_tbl:
xa_destroy(&disk->part_tbl);
bdput(disk->part0);
out_free_disk:
kfree(disk);
return NULL;
}
EXPORT_SYMBOL(__alloc_disk_node);
/**
* 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)
put_device(disk_to_dev(disk));
}
EXPORT_SYMBOL(put_disk);
static void set_disk_ro_uevent(struct gendisk *gd, int ro)
{
char event[] = "DISK_RO=1";
char *envp[] = { event, NULL };
if (!ro)
event[8] = '0';
kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
}
/**
* set_disk_ro - set a gendisk read-only
* @disk: gendisk to operate on
* @read_only: %true to set the disk read-only, %false set the disk read/write
*
* This function is used to indicate whether a given disk device should have its
* read-only flag set. set_disk_ro() is typically used by device drivers to
* indicate whether the underlying physical device is write-protected.
*/
void set_disk_ro(struct gendisk *disk, bool read_only)
{
if (read_only) {
if (test_and_set_bit(GD_READ_ONLY, &disk->state))
return;
} else {
if (!test_and_clear_bit(GD_READ_ONLY, &disk->state))
return;
}
set_disk_ro_uevent(disk, read_only);
}
EXPORT_SYMBOL(set_disk_ro);
int bdev_read_only(struct block_device *bdev)
{
return bdev->bd_read_only || get_disk_ro(bdev->bd_disk);
}
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);
}