linux/block/genhd.c
Ming Lei 2a19b28f79 blk-mq: cancel blk-mq dispatch work in both blk_cleanup_queue and disk_release()
For avoiding to slow down queue destroy, we don't call
blk_mq_quiesce_queue() in blk_cleanup_queue(), instead of delaying to
cancel dispatch work in blk_release_queue().

However, this way has caused kernel oops[1], reported by Changhui. The log
shows that scsi_device can be freed before running blk_release_queue(),
which is expected too since scsi_device is released after the scsi disk
is closed and the scsi_device is removed.

Fixes the issue by canceling blk-mq dispatch work in both blk_cleanup_queue()
and disk_release():

1) when disk_release() is run, the disk has been closed, and any sync
dispatch activities have been done, so canceling dispatch work is enough to
quiesce filesystem I/O dispatch activity.

2) in blk_cleanup_queue(), we only focus on passthrough request, and
passthrough request is always explicitly allocated & freed by
its caller, so once queue is frozen, all sync dispatch activity
for passthrough request has been done, then it is enough to just cancel
dispatch work for avoiding any dispatch activity.

[1] kernel panic log
[12622.769416] BUG: kernel NULL pointer dereference, address: 0000000000000300
[12622.777186] #PF: supervisor read access in kernel mode
[12622.782918] #PF: error_code(0x0000) - not-present page
[12622.788649] PGD 0 P4D 0
[12622.791474] Oops: 0000 [#1] PREEMPT SMP PTI
[12622.796138] CPU: 10 PID: 744 Comm: kworker/10:1H Kdump: loaded Not tainted 5.15.0+ #1
[12622.804877] Hardware name: Dell Inc. PowerEdge R730/0H21J3, BIOS 1.5.4 10/002/2015
[12622.813321] Workqueue: kblockd blk_mq_run_work_fn
[12622.818572] RIP: 0010:sbitmap_get+0x75/0x190
[12622.823336] Code: 85 80 00 00 00 41 8b 57 08 85 d2 0f 84 b1 00 00 00 45 31 e4 48 63 cd 48 8d 1c 49 48 c1 e3 06 49 03 5f 10 4c 8d 6b 40 83 f0 01 <48> 8b 33 44 89 f2 4c 89 ef 0f b6 c8 e8 fa f3 ff ff 83 f8 ff 75 58
[12622.844290] RSP: 0018:ffffb00a446dbd40 EFLAGS: 00010202
[12622.850120] RAX: 0000000000000001 RBX: 0000000000000300 RCX: 0000000000000004
[12622.858082] RDX: 0000000000000006 RSI: 0000000000000082 RDI: ffffa0b7a2dfe030
[12622.866042] RBP: 0000000000000004 R08: 0000000000000001 R09: ffffa0b742721334
[12622.874003] R10: 0000000000000008 R11: 0000000000000008 R12: 0000000000000000
[12622.881964] R13: 0000000000000340 R14: 0000000000000000 R15: ffffa0b7a2dfe030
[12622.889926] FS:  0000000000000000(0000) GS:ffffa0baafb40000(0000) knlGS:0000000000000000
[12622.898956] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[12622.905367] CR2: 0000000000000300 CR3: 0000000641210001 CR4: 00000000001706e0
[12622.913328] Call Trace:
[12622.916055]  <TASK>
[12622.918394]  scsi_mq_get_budget+0x1a/0x110
[12622.922969]  __blk_mq_do_dispatch_sched+0x1d4/0x320
[12622.928404]  ? pick_next_task_fair+0x39/0x390
[12622.933268]  __blk_mq_sched_dispatch_requests+0xf4/0x140
[12622.939194]  blk_mq_sched_dispatch_requests+0x30/0x60
[12622.944829]  __blk_mq_run_hw_queue+0x30/0xa0
[12622.949593]  process_one_work+0x1e8/0x3c0
[12622.954059]  worker_thread+0x50/0x3b0
[12622.958144]  ? rescuer_thread+0x370/0x370
[12622.962616]  kthread+0x158/0x180
[12622.966218]  ? set_kthread_struct+0x40/0x40
[12622.970884]  ret_from_fork+0x22/0x30
[12622.974875]  </TASK>
[12622.977309] Modules linked in: scsi_debug rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs sunrpc dm_multipath intel_rapl_msr intel_rapl_common dell_wmi_descriptor sb_edac rfkill video x86_pkg_temp_thermal intel_powerclamp dcdbas coretemp kvm_intel kvm mgag200 irqbypass i2c_algo_bit rapl drm_kms_helper ipmi_ssif intel_cstate intel_uncore syscopyarea sysfillrect sysimgblt fb_sys_fops pcspkr cec mei_me lpc_ich mei ipmi_si ipmi_devintf ipmi_msghandler acpi_power_meter drm fuse xfs libcrc32c sr_mod cdrom sd_mod t10_pi sg ixgbe ahci libahci crct10dif_pclmul crc32_pclmul crc32c_intel libata megaraid_sas ghash_clmulni_intel tg3 wdat_wdt mdio dca wmi dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_debug]

Reported-by: ChanghuiZhong <czhong@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20211116014343.610501-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-11-15 19:22:13 -07:00

1428 lines
36 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/major.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"
#include "blk-rq-qos.h"
static struct kobject *block_depr;
/*
* Unique, monotonically increasing sequential number associated with block
* devices instances (i.e. incremented each time a device is attached).
* Associating uevents with block devices in userspace is difficult and racy:
* the uevent netlink socket is lossy, and on slow and overloaded systems has
* a very high latency.
* Block devices do not have exclusive owners in userspace, any process can set
* one up (e.g. loop devices). Moreover, device names can be reused (e.g. loop0
* can be reused again and again).
* A userspace process setting up a block device and watching for its events
* cannot thus reliably tell whether an event relates to the device it just set
* up or another earlier instance with the same name.
* This sequential number allows userspace processes to solve this problem, and
* uniquely associate an uevent to the lifetime to a device.
*/
static atomic64_t diskseq;
/* for extended dynamic devt allocation, currently only one major is used */
#define NR_EXT_DEVT (1 << MINORBITS)
static DEFINE_IDA(ext_devt_ida);
void set_capacity(struct gendisk *disk, sector_t sectors)
{
struct block_device *bdev = disk->part0;
spin_lock(&bdev->bd_size_lock);
i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
bdev->bd_nr_sectors = sectors;
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_live(disk) ||
(disk->flags & GENHD_FL_HIDDEN))
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 block device into the supplied buffer
* and return a pointer to that same buffer for convenience.
*
* Note: do not use this in new code, use the %pg specifier to sprintf and
* printk insted.
*/
const char *bdevname(struct block_device *bdev, char *buf)
{
struct gendisk *hd = bdev->bd_disk;
int partno = bdev->bd_partno;
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;
}
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;
}
/*
* 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);
static DEFINE_SPINLOCK(major_names_spinlock);
/* index in the above - for now: assume no multimajor ranges */
static inline int major_to_index(unsigned major)
{
return major % BLKDEV_MAJOR_HASH_SIZE;
}
#ifdef CONFIG_PROC_FS
void blkdev_show(struct seq_file *seqf, off_t offset)
{
struct blk_major_name *dp;
spin_lock(&major_names_spinlock);
for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next)
if (dp->major == offset)
seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
spin_unlock(&major_names_spinlock);
}
#endif /* CONFIG_PROC_FS */
/**
* __register_blkdev - register a new block device
*
* @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
* @major = 0, try to allocate any unused major number.
* @name: the name of the new block device as a zero terminated string
* @probe: pre-devtmpfs / pre-udev callback used to create disks when their
* pre-created device node is accessed. When a probe call uses
* add_disk() and it fails the driver must cleanup resources. This
* interface may soon be removed.
*
* The @name must be unique within the system.
*
* The return value depends on the @major input parameter:
*
* - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
* then the function returns zero on success, or a negative error code
* - if any unused major number was requested with @major = 0 parameter
* then the return value is the allocated major number in range
* [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
*
* See Documentation/admin-guide/devices.txt for the list of allocated
* major numbers.
*
* Use register_blkdev instead for any new code.
*/
int __register_blkdev(unsigned int major, const char *name,
void (*probe)(dev_t devt))
{
struct blk_major_name **n, *p;
int index, ret = 0;
mutex_lock(&major_names_lock);
/* temporary */
if (major == 0) {
for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
if (major_names[index] == NULL)
break;
}
if (index == 0) {
printk("%s: failed to get major for %s\n",
__func__, name);
ret = -EBUSY;
goto out;
}
major = index;
ret = major;
}
if (major >= BLKDEV_MAJOR_MAX) {
pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
__func__, major, BLKDEV_MAJOR_MAX-1, name);
ret = -EINVAL;
goto out;
}
p = kmalloc(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);
spin_lock(&major_names_spinlock);
for (n = &major_names[index]; *n; n = &(*n)->next) {
if ((*n)->major == major)
break;
}
if (!*n)
*n = p;
else
ret = -EBUSY;
spin_unlock(&major_names_spinlock);
if (ret < 0) {
printk("register_blkdev: cannot get major %u for %s\n",
major, name);
kfree(p);
}
out:
mutex_unlock(&major_names_lock);
return ret;
}
EXPORT_SYMBOL(__register_blkdev);
void unregister_blkdev(unsigned int major, const char *name)
{
struct blk_major_name **n;
struct blk_major_name *p = NULL;
int index = major_to_index(major);
mutex_lock(&major_names_lock);
spin_lock(&major_names_spinlock);
for (n = &major_names[index]; *n; n = &(*n)->next)
if ((*n)->major == major)
break;
if (!*n || strcmp((*n)->name, name)) {
WARN_ON(1);
} else {
p = *n;
*n = p->next;
}
spin_unlock(&major_names_spinlock);
mutex_unlock(&major_names_lock);
kfree(p);
}
EXPORT_SYMBOL(unregister_blkdev);
int blk_alloc_ext_minor(void)
{
int idx;
idx = ida_alloc_range(&ext_devt_ida, 0, NR_EXT_DEVT, GFP_KERNEL);
if (idx == -ENOSPC)
return -EBUSY;
return idx;
}
void blk_free_ext_minor(unsigned int minor)
{
ida_free(&ext_devt_ida, minor);
}
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 block_device *part;
unsigned long idx;
rcu_read_lock();
xa_for_each(&disk->part_tbl, idx, part) {
if (bdev_is_partition(part) && !bdev_nr_sectors(part))
continue;
if (!kobject_get_unless_zero(&part->bd_device.kobj))
continue;
rcu_read_unlock();
kobject_uevent(bdev_kobj(part), action);
put_device(&part->bd_device);
rcu_read_lock();
}
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(disk_uevent);
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);
}
/**
* device_add_disk - add disk information to kernel list
* @parent: parent device for the disk
* @disk: per-device partitioning information
* @groups: Additional per-device sysfs groups
*
* This function registers the partitioning information in @disk
* with the kernel.
*/
int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
const struct attribute_group **groups)
{
struct device *ddev = disk_to_dev(disk);
int ret;
/*
* 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.
*/
elevator_init_mq(disk->queue);
/*
* If the driver provides an explicit major number it also must provide
* the number of minors numbers supported, and those will be used to
* setup the gendisk.
* Otherwise just allocate the device numbers for both the whole device
* and all partitions from the extended dev_t space.
*/
if (disk->major) {
if (WARN_ON(!disk->minors))
return -EINVAL;
if (disk->minors > DISK_MAX_PARTS) {
pr_err("block: can't allocate more than %d partitions\n",
DISK_MAX_PARTS);
disk->minors = DISK_MAX_PARTS;
}
} else {
if (WARN_ON(disk->minors))
return -EINVAL;
ret = blk_alloc_ext_minor();
if (ret < 0)
return ret;
disk->major = BLOCK_EXT_MAJOR;
disk->first_minor = ret;
disk->flags |= GENHD_FL_EXT_DEVT;
}
ret = disk_alloc_events(disk);
if (ret)
goto out_free_ext_minor;
/* delay uevents, until we scanned partition table */
dev_set_uevent_suppress(ddev, 1);
ddev->parent = parent;
ddev->groups = groups;
dev_set_name(ddev, "%s", disk->disk_name);
if (!(disk->flags & GENHD_FL_HIDDEN))
ddev->devt = MKDEV(disk->major, disk->first_minor);
ret = device_add(ddev);
if (ret)
goto out_disk_release_events;
if (!sysfs_deprecated) {
ret = sysfs_create_link(block_depr, &ddev->kobj,
kobject_name(&ddev->kobj));
if (ret)
goto out_device_del;
}
/*
* avoid probable deadlock caused by allocating memory with
* GFP_KERNEL in runtime_resume callback of its all ancestor
* devices
*/
pm_runtime_set_memalloc_noio(ddev, true);
ret = blk_integrity_add(disk);
if (ret)
goto out_del_block_link;
disk->part0->bd_holder_dir =
kobject_create_and_add("holders", &ddev->kobj);
if (!disk->part0->bd_holder_dir) {
ret = -ENOMEM;
goto out_del_integrity;
}
disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
if (!disk->slave_dir) {
ret = -ENOMEM;
goto out_put_holder_dir;
}
ret = bd_register_pending_holders(disk);
if (ret < 0)
goto out_put_slave_dir;
ret = blk_register_queue(disk);
if (ret)
goto out_put_slave_dir;
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 {
ret = bdi_register(disk->bdi, "%u:%u",
disk->major, disk->first_minor);
if (ret)
goto out_unregister_queue;
bdi_set_owner(disk->bdi, ddev);
ret = sysfs_create_link(&ddev->kobj,
&disk->bdi->dev->kobj, "bdi");
if (ret)
goto out_unregister_bdi;
bdev_add(disk->part0, ddev->devt);
disk_scan_partitions(disk);
/*
* Announce the disk and partitions after all partitions are
* created. (for hidden disks uevents remain suppressed forever)
*/
dev_set_uevent_suppress(ddev, 0);
disk_uevent(disk, KOBJ_ADD);
}
disk_update_readahead(disk);
disk_add_events(disk);
return 0;
out_unregister_bdi:
if (!(disk->flags & GENHD_FL_HIDDEN))
bdi_unregister(disk->bdi);
out_unregister_queue:
blk_unregister_queue(disk);
out_put_slave_dir:
kobject_put(disk->slave_dir);
out_put_holder_dir:
kobject_put(disk->part0->bd_holder_dir);
out_del_integrity:
blk_integrity_del(disk);
out_del_block_link:
if (!sysfs_deprecated)
sysfs_remove_link(block_depr, dev_name(ddev));
out_device_del:
device_del(ddev);
out_disk_release_events:
disk_release_events(disk);
out_free_ext_minor:
if (disk->major == BLOCK_EXT_MAJOR)
blk_free_ext_minor(disk->first_minor);
return ret;
}
EXPORT_SYMBOL(device_add_disk);
/**
* 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 request_queue *q = disk->queue;
might_sleep();
if (WARN_ON_ONCE(!disk_live(disk) && !(disk->flags & GENHD_FL_HIDDEN)))
return;
blk_integrity_del(disk);
disk_del_events(disk);
mutex_lock(&disk->open_mutex);
remove_inode_hash(disk->part0->bd_inode);
blk_drop_partitions(disk);
mutex_unlock(&disk->open_mutex);
fsync_bdev(disk->part0);
__invalidate_device(disk->part0, true);
/*
* Fail any new I/O.
*/
set_bit(GD_DEAD, &disk->state);
set_capacity(disk, 0);
/*
* Prevent new I/O from crossing bio_queue_enter().
*/
blk_queue_start_drain(q);
if (!(disk->flags & GENHD_FL_HIDDEN)) {
sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
/*
* Unregister bdi before releasing device numbers (as they can
* get reused and we'd get clashes in sysfs).
*/
bdi_unregister(disk->bdi);
}
blk_unregister_queue(disk);
kobject_put(disk->part0->bd_holder_dir);
kobject_put(disk->slave_dir);
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));
blk_mq_freeze_queue_wait(q);
rq_qos_exit(q);
blk_sync_queue(q);
blk_flush_integrity();
/*
* Allow using passthrough request again after the queue is torn down.
*/
blk_queue_flag_clear(QUEUE_FLAG_INIT_DONE, q);
__blk_mq_unfreeze_queue(q, true);
}
EXPORT_SYMBOL(del_gendisk);
/**
* invalidate_disk - invalidate the disk
* @disk: the struct gendisk to invalidate
*
* A helper to invalidates the disk. It will clean the disk's associated
* buffer/page caches and reset its internal states so that the disk
* can be reused by the drivers.
*
* Context: can sleep
*/
void invalidate_disk(struct gendisk *disk)
{
struct block_device *bdev = disk->part0;
invalidate_bdev(bdev);
bdev->bd_inode->i_mapping->wb_err = 0;
set_capacity(disk, 0);
}
EXPORT_SYMBOL(invalidate_disk);
/* sysfs access to bad-blocks list. */
static ssize_t disk_badblocks_show(struct device *dev,
struct device_attribute *attr,
char *page)
{
struct gendisk *disk = dev_to_disk(dev);
if (!disk->bb)
return 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));
}
/*
* 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 block_device *part;
char devt_buf[BDEVT_SIZE];
unsigned long idx;
/*
* 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.
*/
rcu_read_lock();
xa_for_each(&disk->part_tbl, idx, part) {
if (!bdev_nr_sectors(part))
continue;
printk("%s%s %10llu %pg %s",
bdev_is_partition(part) ? " " : "",
bdevt_str(part->bd_dev, devt_buf),
bdev_nr_sectors(part) >> 1, part,
part->bd_meta_info ?
part->bd_meta_info->uuid : "");
if (bdev_is_partition(part))
printk("\n");
else if (dev->parent && dev->parent->driver)
printk(" driver: %s\n",
dev->parent->driver->name);
else
printk(" (driver?)\n");
}
rcu_read_unlock();
}
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 block_device *part;
unsigned long idx;
/* 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;
rcu_read_lock();
xa_for_each(&sgp->part_tbl, idx, part) {
if (!bdev_nr_sectors(part))
continue;
seq_printf(seqf, "%4d %7d %10llu %pg\n",
MAJOR(part->bd_dev), MINOR(part->bd_dev),
bdev_nr_sectors(part) >> 1, part);
}
rcu_read_unlock();
return 0;
}
static const struct seq_operations partitions_op = {
.start = show_partition_start,
.next = disk_seqf_next,
.stop = disk_seqf_stop,
.show = show_partition
};
#endif
static int __init genhd_device_init(void)
{
int error;
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_get_queue(bdev);
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_get_queue(bdev);
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 ssize_t diskseq_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gendisk *disk = dev_to_disk(dev);
return sprintf(buf, "%llu\n", disk->diskseq);
}
static DEVICE_ATTR(range, 0444, disk_range_show, NULL);
static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL);
static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL);
static DEVICE_ATTR(hidden, 0444, disk_hidden_show, NULL);
static DEVICE_ATTR(ro, 0444, disk_ro_show, NULL);
static DEVICE_ATTR(size, 0444, part_size_show, NULL);
static DEVICE_ATTR(alignment_offset, 0444, disk_alignment_offset_show, NULL);
static DEVICE_ATTR(discard_alignment, 0444, disk_discard_alignment_show, NULL);
static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL);
static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store);
static DEVICE_ATTR(diskseq, 0444, diskseq_show, NULL);
#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,
&dev_attr_events.attr,
&dev_attr_events_async.attr,
&dev_attr_events_poll_msecs.attr,
&dev_attr_diskseq.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();
WARN_ON_ONCE(disk_live(disk));
blk_mq_cancel_work_sync(disk->queue);
disk_release_events(disk);
kfree(disk->random);
xa_destroy(&disk->part_tbl);
disk->queue->disk = NULL;
blk_put_queue(disk->queue);
iput(disk->part0->bd_inode); /* frees the disk */
}
static int block_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct gendisk *disk = dev_to_disk(dev);
return add_uevent_var(env, "DISKSEQ=%llu", disk->diskseq);
}
struct class block_class = {
.name = "block",
.dev_uevent = block_uevent,
};
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 block_device *hd;
unsigned int inflight;
struct disk_stats stat;
unsigned long idx;
/*
if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
seq_puts(seqf, "major minor name"
" rio rmerge rsect ruse wio wmerge "
"wsect wuse running use aveq"
"\n\n");
*/
rcu_read_lock();
xa_for_each(&gp->part_tbl, idx, hd) {
if (bdev_is_partition(hd) && !bdev_nr_sectors(hd))
continue;
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 %pg "
"%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), hd,
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)
);
}
rcu_read_unlock();
return 0;
}
static const struct seq_operations diskstats_op = {
.start = disk_seqf_start,
.next = disk_seqf_next,
.stop = disk_seqf_stop,
.show = diskstats_show
};
static int __init proc_genhd_init(void)
{
proc_create_seq("diskstats", 0, NULL, &diskstats_op);
proc_create_seq("partitions", 0, NULL, &partitions_op);
return 0;
}
module_init(proc_genhd_init);
#endif /* CONFIG_PROC_FS */
dev_t part_devt(struct gendisk *disk, u8 partno)
{
struct block_device *part;
dev_t devt = 0;
rcu_read_lock();
part = xa_load(&disk->part_tbl, partno);
if (part)
devt = part->bd_dev;
rcu_read_unlock();
return devt;
}
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);
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);
} else {
devt = part_devt(disk, partno);
if (devt)
break;
}
}
class_dev_iter_exit(&iter);
return devt;
}
struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
struct lock_class_key *lkclass)
{
struct gendisk *disk;
if (!blk_get_queue(q))
return NULL;
disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
if (!disk)
goto out_put_queue;
disk->bdi = bdi_alloc(node_id);
if (!disk->bdi)
goto out_free_disk;
/* bdev_alloc() might need the queue, set before the first call */
disk->queue = q;
disk->part0 = bdev_alloc(disk, 0);
if (!disk->part0)
goto out_free_bdi;
disk->node_id = node_id;
mutex_init(&disk->open_mutex);
xa_init(&disk->part_tbl);
if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL))
goto out_destroy_part_tbl;
rand_initialize_disk(disk);
disk_to_dev(disk)->class = &block_class;
disk_to_dev(disk)->type = &disk_type;
device_initialize(disk_to_dev(disk));
inc_diskseq(disk);
q->disk = disk;
lockdep_init_map(&disk->lockdep_map, "(bio completion)", lkclass, 0);
#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
INIT_LIST_HEAD(&disk->slave_bdevs);
#endif
return disk;
out_destroy_part_tbl:
xa_destroy(&disk->part_tbl);
disk->part0->bd_disk = NULL;
iput(disk->part0->bd_inode);
out_free_bdi:
bdi_put(disk->bdi);
out_free_disk:
kfree(disk);
out_put_queue:
blk_put_queue(q);
return NULL;
}
EXPORT_SYMBOL(__alloc_disk_node);
struct gendisk *__blk_alloc_disk(int node, struct lock_class_key *lkclass)
{
struct request_queue *q;
struct gendisk *disk;
q = blk_alloc_queue(node);
if (!q)
return NULL;
disk = __alloc_disk_node(q, node, lkclass);
if (!disk) {
blk_cleanup_queue(q);
return NULL;
}
return disk;
}
EXPORT_SYMBOL(__blk_alloc_disk);
/**
* put_disk - decrements the gendisk refcount
* @disk: the struct gendisk to decrement the refcount for
*
* This decrements the refcount for the struct gendisk. When this reaches 0
* we'll have disk_release() called.
*
* 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);
/**
* blk_cleanup_disk - shutdown a gendisk allocated by blk_alloc_disk
* @disk: gendisk to shutdown
*
* Mark the queue hanging off @disk DYING, drain all pending requests, then mark
* the queue DEAD, destroy and put it and the gendisk structure.
*
* Context: can sleep
*/
void blk_cleanup_disk(struct gendisk *disk)
{
blk_cleanup_queue(disk->queue);
put_disk(disk);
}
EXPORT_SYMBOL(blk_cleanup_disk);
static void set_disk_ro_uevent(struct gendisk *gd, int ro)
{
char event[] = "DISK_RO=1";
char *envp[] = { event, NULL };
if (!ro)
event[8] = '0';
kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
}
/**
* set_disk_ro - set a gendisk read-only
* @disk: gendisk to operate on
* @read_only: %true to set the disk read-only, %false set the disk read/write
*
* This function is used to indicate whether a given disk device should have its
* read-only flag set. set_disk_ro() is typically used by device drivers to
* indicate whether the underlying physical device is write-protected.
*/
void set_disk_ro(struct gendisk *disk, bool read_only)
{
if (read_only) {
if (test_and_set_bit(GD_READ_ONLY, &disk->state))
return;
} else {
if (!test_and_clear_bit(GD_READ_ONLY, &disk->state))
return;
}
set_disk_ro_uevent(disk, read_only);
}
EXPORT_SYMBOL(set_disk_ro);
void inc_diskseq(struct gendisk *disk)
{
disk->diskseq = atomic64_inc_return(&diskseq);
}