mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![Kent Overstreet](/assets/img/avatar_default.png)
The way the block layer is currently written, it goes to great lengths to avoid having to split bios; upper layer code (such as bio_add_page()) checks what the underlying device can handle and tries to always create bios that don't need to be split. But this approach becomes unwieldy and eventually breaks down with stacked devices and devices with dynamic limits, and it adds a lot of complexity. If the block layer could split bios as needed, we could eliminate a lot of complexity elsewhere - particularly in stacked drivers. Code that creates bios can then create whatever size bios are convenient, and more importantly stacked drivers don't have to deal with both their own bio size limitations and the limitations of the (potentially multiple) devices underneath them. In the future this will let us delete merge_bvec_fn and a bunch of other code. We do this by adding calls to blk_queue_split() to the various make_request functions that need it - a few can already handle arbitrary size bios. Note that we add the call _after_ any call to blk_queue_bounce(); this means that blk_queue_split() and blk_recalc_rq_segments() don't need to be concerned with bouncing affecting segment merging. Some make_request_fn() callbacks were simple enough to audit and verify they don't need blk_queue_split() calls. The skipped ones are: * nfhd_make_request (arch/m68k/emu/nfblock.c) * axon_ram_make_request (arch/powerpc/sysdev/axonram.c) * simdisk_make_request (arch/xtensa/platforms/iss/simdisk.c) * brd_make_request (ramdisk - drivers/block/brd.c) * mtip_submit_request (drivers/block/mtip32xx/mtip32xx.c) * loop_make_request * null_queue_bio * bcache's make_request fns Some others are almost certainly safe to remove now, but will be left for future patches. Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ming Lei <ming.lei@canonical.com> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina <jkosina@suse.cz> Cc: Geoff Levand <geoff@infradead.org> Cc: Jim Paris <jim@jtan.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Oleg Drokin <oleg.drokin@intel.com> Cc: Andreas Dilger <andreas.dilger@intel.com> Acked-by: NeilBrown <neilb@suse.de> (for the 'md/md.c' bits) Acked-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [dpark: skip more mq-based drivers, resolve merge conflicts, etc.] Signed-off-by: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> Signed-off-by: Jens Axboe <axboe@fb.com>
654 lines
16 KiB
C
654 lines
16 KiB
C
/*
|
|
* Functions related to sysfs handling
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/module.h>
|
|
#include <linux/bio.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/backing-dev.h>
|
|
#include <linux/blktrace_api.h>
|
|
#include <linux/blk-mq.h>
|
|
#include <linux/blk-cgroup.h>
|
|
|
|
#include "blk.h"
|
|
#include "blk-mq.h"
|
|
|
|
struct queue_sysfs_entry {
|
|
struct attribute attr;
|
|
ssize_t (*show)(struct request_queue *, char *);
|
|
ssize_t (*store)(struct request_queue *, const char *, size_t);
|
|
};
|
|
|
|
static ssize_t
|
|
queue_var_show(unsigned long var, char *page)
|
|
{
|
|
return sprintf(page, "%lu\n", var);
|
|
}
|
|
|
|
static ssize_t
|
|
queue_var_store(unsigned long *var, const char *page, size_t count)
|
|
{
|
|
int err;
|
|
unsigned long v;
|
|
|
|
err = kstrtoul(page, 10, &v);
|
|
if (err || v > UINT_MAX)
|
|
return -EINVAL;
|
|
|
|
*var = v;
|
|
|
|
return count;
|
|
}
|
|
|
|
static ssize_t queue_requests_show(struct request_queue *q, char *page)
|
|
{
|
|
return queue_var_show(q->nr_requests, (page));
|
|
}
|
|
|
|
static ssize_t
|
|
queue_requests_store(struct request_queue *q, const char *page, size_t count)
|
|
{
|
|
unsigned long nr;
|
|
int ret, err;
|
|
|
|
if (!q->request_fn && !q->mq_ops)
|
|
return -EINVAL;
|
|
|
|
ret = queue_var_store(&nr, page, count);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (nr < BLKDEV_MIN_RQ)
|
|
nr = BLKDEV_MIN_RQ;
|
|
|
|
if (q->request_fn)
|
|
err = blk_update_nr_requests(q, nr);
|
|
else
|
|
err = blk_mq_update_nr_requests(q, nr);
|
|
|
|
if (err)
|
|
return err;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t queue_ra_show(struct request_queue *q, char *page)
|
|
{
|
|
unsigned long ra_kb = q->backing_dev_info.ra_pages <<
|
|
(PAGE_CACHE_SHIFT - 10);
|
|
|
|
return queue_var_show(ra_kb, (page));
|
|
}
|
|
|
|
static ssize_t
|
|
queue_ra_store(struct request_queue *q, const char *page, size_t count)
|
|
{
|
|
unsigned long ra_kb;
|
|
ssize_t ret = queue_var_store(&ra_kb, page, count);
|
|
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
|
|
{
|
|
int max_sectors_kb = queue_max_sectors(q) >> 1;
|
|
|
|
return queue_var_show(max_sectors_kb, (page));
|
|
}
|
|
|
|
static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
|
|
{
|
|
return queue_var_show(queue_max_segments(q), (page));
|
|
}
|
|
|
|
static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
|
|
{
|
|
return queue_var_show(q->limits.max_integrity_segments, (page));
|
|
}
|
|
|
|
static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
|
|
{
|
|
if (blk_queue_cluster(q))
|
|
return queue_var_show(queue_max_segment_size(q), (page));
|
|
|
|
return queue_var_show(PAGE_CACHE_SIZE, (page));
|
|
}
|
|
|
|
static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
|
|
{
|
|
return queue_var_show(queue_logical_block_size(q), page);
|
|
}
|
|
|
|
static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
|
|
{
|
|
return queue_var_show(queue_physical_block_size(q), page);
|
|
}
|
|
|
|
static ssize_t queue_io_min_show(struct request_queue *q, char *page)
|
|
{
|
|
return queue_var_show(queue_io_min(q), page);
|
|
}
|
|
|
|
static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
|
|
{
|
|
return queue_var_show(queue_io_opt(q), page);
|
|
}
|
|
|
|
static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
|
|
{
|
|
return queue_var_show(q->limits.discard_granularity, page);
|
|
}
|
|
|
|
static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page)
|
|
{
|
|
unsigned long long val;
|
|
|
|
val = q->limits.max_hw_discard_sectors << 9;
|
|
return sprintf(page, "%llu\n", val);
|
|
}
|
|
|
|
static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
|
|
{
|
|
return sprintf(page, "%llu\n",
|
|
(unsigned long long)q->limits.max_discard_sectors << 9);
|
|
}
|
|
|
|
static ssize_t queue_discard_max_store(struct request_queue *q,
|
|
const char *page, size_t count)
|
|
{
|
|
unsigned long max_discard;
|
|
ssize_t ret = queue_var_store(&max_discard, page, count);
|
|
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (max_discard & (q->limits.discard_granularity - 1))
|
|
return -EINVAL;
|
|
|
|
max_discard >>= 9;
|
|
if (max_discard > UINT_MAX)
|
|
return -EINVAL;
|
|
|
|
if (max_discard > q->limits.max_hw_discard_sectors)
|
|
max_discard = q->limits.max_hw_discard_sectors;
|
|
|
|
q->limits.max_discard_sectors = max_discard;
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
|
|
{
|
|
return queue_var_show(queue_discard_zeroes_data(q), page);
|
|
}
|
|
|
|
static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
|
|
{
|
|
return sprintf(page, "%llu\n",
|
|
(unsigned long long)q->limits.max_write_same_sectors << 9);
|
|
}
|
|
|
|
|
|
static ssize_t
|
|
queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
|
|
{
|
|
unsigned long max_sectors_kb,
|
|
max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
|
|
page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
|
|
ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
|
|
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
|
|
return -EINVAL;
|
|
|
|
spin_lock_irq(q->queue_lock);
|
|
q->limits.max_sectors = max_sectors_kb << 1;
|
|
spin_unlock_irq(q->queue_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
|
|
{
|
|
int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
|
|
|
|
return queue_var_show(max_hw_sectors_kb, (page));
|
|
}
|
|
|
|
#define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \
|
|
static ssize_t \
|
|
queue_show_##name(struct request_queue *q, char *page) \
|
|
{ \
|
|
int bit; \
|
|
bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \
|
|
return queue_var_show(neg ? !bit : bit, page); \
|
|
} \
|
|
static ssize_t \
|
|
queue_store_##name(struct request_queue *q, const char *page, size_t count) \
|
|
{ \
|
|
unsigned long val; \
|
|
ssize_t ret; \
|
|
ret = queue_var_store(&val, page, count); \
|
|
if (ret < 0) \
|
|
return ret; \
|
|
if (neg) \
|
|
val = !val; \
|
|
\
|
|
spin_lock_irq(q->queue_lock); \
|
|
if (val) \
|
|
queue_flag_set(QUEUE_FLAG_##flag, q); \
|
|
else \
|
|
queue_flag_clear(QUEUE_FLAG_##flag, q); \
|
|
spin_unlock_irq(q->queue_lock); \
|
|
return ret; \
|
|
}
|
|
|
|
QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
|
|
QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
|
|
QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
|
|
#undef QUEUE_SYSFS_BIT_FNS
|
|
|
|
static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
|
|
{
|
|
return queue_var_show((blk_queue_nomerges(q) << 1) |
|
|
blk_queue_noxmerges(q), page);
|
|
}
|
|
|
|
static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
|
|
size_t count)
|
|
{
|
|
unsigned long nm;
|
|
ssize_t ret = queue_var_store(&nm, page, count);
|
|
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
spin_lock_irq(q->queue_lock);
|
|
queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
|
|
queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
|
|
if (nm == 2)
|
|
queue_flag_set(QUEUE_FLAG_NOMERGES, q);
|
|
else if (nm)
|
|
queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
|
|
spin_unlock_irq(q->queue_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
|
|
{
|
|
bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
|
|
bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
|
|
|
|
return queue_var_show(set << force, page);
|
|
}
|
|
|
|
static ssize_t
|
|
queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
|
|
{
|
|
ssize_t ret = -EINVAL;
|
|
#ifdef CONFIG_SMP
|
|
unsigned long val;
|
|
|
|
ret = queue_var_store(&val, page, count);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
spin_lock_irq(q->queue_lock);
|
|
if (val == 2) {
|
|
queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
|
|
queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
|
|
} else if (val == 1) {
|
|
queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
|
|
queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
|
|
} else if (val == 0) {
|
|
queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
|
|
queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
|
|
}
|
|
spin_unlock_irq(q->queue_lock);
|
|
#endif
|
|
return ret;
|
|
}
|
|
|
|
static struct queue_sysfs_entry queue_requests_entry = {
|
|
.attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
|
|
.show = queue_requests_show,
|
|
.store = queue_requests_store,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_ra_entry = {
|
|
.attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
|
|
.show = queue_ra_show,
|
|
.store = queue_ra_store,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_max_sectors_entry = {
|
|
.attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
|
|
.show = queue_max_sectors_show,
|
|
.store = queue_max_sectors_store,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
|
|
.attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
|
|
.show = queue_max_hw_sectors_show,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_max_segments_entry = {
|
|
.attr = {.name = "max_segments", .mode = S_IRUGO },
|
|
.show = queue_max_segments_show,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
|
|
.attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
|
|
.show = queue_max_integrity_segments_show,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_max_segment_size_entry = {
|
|
.attr = {.name = "max_segment_size", .mode = S_IRUGO },
|
|
.show = queue_max_segment_size_show,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_iosched_entry = {
|
|
.attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
|
|
.show = elv_iosched_show,
|
|
.store = elv_iosched_store,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_hw_sector_size_entry = {
|
|
.attr = {.name = "hw_sector_size", .mode = S_IRUGO },
|
|
.show = queue_logical_block_size_show,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_logical_block_size_entry = {
|
|
.attr = {.name = "logical_block_size", .mode = S_IRUGO },
|
|
.show = queue_logical_block_size_show,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_physical_block_size_entry = {
|
|
.attr = {.name = "physical_block_size", .mode = S_IRUGO },
|
|
.show = queue_physical_block_size_show,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_io_min_entry = {
|
|
.attr = {.name = "minimum_io_size", .mode = S_IRUGO },
|
|
.show = queue_io_min_show,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_io_opt_entry = {
|
|
.attr = {.name = "optimal_io_size", .mode = S_IRUGO },
|
|
.show = queue_io_opt_show,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_discard_granularity_entry = {
|
|
.attr = {.name = "discard_granularity", .mode = S_IRUGO },
|
|
.show = queue_discard_granularity_show,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_discard_max_hw_entry = {
|
|
.attr = {.name = "discard_max_hw_bytes", .mode = S_IRUGO },
|
|
.show = queue_discard_max_hw_show,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_discard_max_entry = {
|
|
.attr = {.name = "discard_max_bytes", .mode = S_IRUGO | S_IWUSR },
|
|
.show = queue_discard_max_show,
|
|
.store = queue_discard_max_store,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
|
|
.attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
|
|
.show = queue_discard_zeroes_data_show,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_write_same_max_entry = {
|
|
.attr = {.name = "write_same_max_bytes", .mode = S_IRUGO },
|
|
.show = queue_write_same_max_show,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_nonrot_entry = {
|
|
.attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
|
|
.show = queue_show_nonrot,
|
|
.store = queue_store_nonrot,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_nomerges_entry = {
|
|
.attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
|
|
.show = queue_nomerges_show,
|
|
.store = queue_nomerges_store,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_rq_affinity_entry = {
|
|
.attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
|
|
.show = queue_rq_affinity_show,
|
|
.store = queue_rq_affinity_store,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_iostats_entry = {
|
|
.attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
|
|
.show = queue_show_iostats,
|
|
.store = queue_store_iostats,
|
|
};
|
|
|
|
static struct queue_sysfs_entry queue_random_entry = {
|
|
.attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
|
|
.show = queue_show_random,
|
|
.store = queue_store_random,
|
|
};
|
|
|
|
static struct attribute *default_attrs[] = {
|
|
&queue_requests_entry.attr,
|
|
&queue_ra_entry.attr,
|
|
&queue_max_hw_sectors_entry.attr,
|
|
&queue_max_sectors_entry.attr,
|
|
&queue_max_segments_entry.attr,
|
|
&queue_max_integrity_segments_entry.attr,
|
|
&queue_max_segment_size_entry.attr,
|
|
&queue_iosched_entry.attr,
|
|
&queue_hw_sector_size_entry.attr,
|
|
&queue_logical_block_size_entry.attr,
|
|
&queue_physical_block_size_entry.attr,
|
|
&queue_io_min_entry.attr,
|
|
&queue_io_opt_entry.attr,
|
|
&queue_discard_granularity_entry.attr,
|
|
&queue_discard_max_entry.attr,
|
|
&queue_discard_max_hw_entry.attr,
|
|
&queue_discard_zeroes_data_entry.attr,
|
|
&queue_write_same_max_entry.attr,
|
|
&queue_nonrot_entry.attr,
|
|
&queue_nomerges_entry.attr,
|
|
&queue_rq_affinity_entry.attr,
|
|
&queue_iostats_entry.attr,
|
|
&queue_random_entry.attr,
|
|
NULL,
|
|
};
|
|
|
|
#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
|
|
|
|
static ssize_t
|
|
queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
|
|
{
|
|
struct queue_sysfs_entry *entry = to_queue(attr);
|
|
struct request_queue *q =
|
|
container_of(kobj, struct request_queue, kobj);
|
|
ssize_t res;
|
|
|
|
if (!entry->show)
|
|
return -EIO;
|
|
mutex_lock(&q->sysfs_lock);
|
|
if (blk_queue_dying(q)) {
|
|
mutex_unlock(&q->sysfs_lock);
|
|
return -ENOENT;
|
|
}
|
|
res = entry->show(q, page);
|
|
mutex_unlock(&q->sysfs_lock);
|
|
return res;
|
|
}
|
|
|
|
static ssize_t
|
|
queue_attr_store(struct kobject *kobj, struct attribute *attr,
|
|
const char *page, size_t length)
|
|
{
|
|
struct queue_sysfs_entry *entry = to_queue(attr);
|
|
struct request_queue *q;
|
|
ssize_t res;
|
|
|
|
if (!entry->store)
|
|
return -EIO;
|
|
|
|
q = container_of(kobj, struct request_queue, kobj);
|
|
mutex_lock(&q->sysfs_lock);
|
|
if (blk_queue_dying(q)) {
|
|
mutex_unlock(&q->sysfs_lock);
|
|
return -ENOENT;
|
|
}
|
|
res = entry->store(q, page, length);
|
|
mutex_unlock(&q->sysfs_lock);
|
|
return res;
|
|
}
|
|
|
|
static void blk_free_queue_rcu(struct rcu_head *rcu_head)
|
|
{
|
|
struct request_queue *q = container_of(rcu_head, struct request_queue,
|
|
rcu_head);
|
|
kmem_cache_free(blk_requestq_cachep, q);
|
|
}
|
|
|
|
/**
|
|
* blk_release_queue: - release a &struct request_queue when it is no longer needed
|
|
* @kobj: the kobj belonging to the request queue to be released
|
|
*
|
|
* Description:
|
|
* blk_release_queue is the pair to blk_init_queue() or
|
|
* blk_queue_make_request(). It should be called when a request queue is
|
|
* being released; typically when a block device is being de-registered.
|
|
* Currently, its primary task it to free all the &struct request
|
|
* structures that were allocated to the queue and the queue itself.
|
|
*
|
|
* Note:
|
|
* The low level driver must have finished any outstanding requests first
|
|
* via blk_cleanup_queue().
|
|
**/
|
|
static void blk_release_queue(struct kobject *kobj)
|
|
{
|
|
struct request_queue *q =
|
|
container_of(kobj, struct request_queue, kobj);
|
|
|
|
blkcg_exit_queue(q);
|
|
|
|
if (q->elevator) {
|
|
spin_lock_irq(q->queue_lock);
|
|
ioc_clear_queue(q);
|
|
spin_unlock_irq(q->queue_lock);
|
|
elevator_exit(q->elevator);
|
|
}
|
|
|
|
blk_exit_rl(&q->root_rl);
|
|
|
|
if (q->queue_tags)
|
|
__blk_queue_free_tags(q);
|
|
|
|
if (!q->mq_ops)
|
|
blk_free_flush_queue(q->fq);
|
|
else
|
|
blk_mq_release(q);
|
|
|
|
blk_trace_shutdown(q);
|
|
|
|
if (q->bio_split)
|
|
bioset_free(q->bio_split);
|
|
|
|
ida_simple_remove(&blk_queue_ida, q->id);
|
|
call_rcu(&q->rcu_head, blk_free_queue_rcu);
|
|
}
|
|
|
|
static const struct sysfs_ops queue_sysfs_ops = {
|
|
.show = queue_attr_show,
|
|
.store = queue_attr_store,
|
|
};
|
|
|
|
struct kobj_type blk_queue_ktype = {
|
|
.sysfs_ops = &queue_sysfs_ops,
|
|
.default_attrs = default_attrs,
|
|
.release = blk_release_queue,
|
|
};
|
|
|
|
int blk_register_queue(struct gendisk *disk)
|
|
{
|
|
int ret;
|
|
struct device *dev = disk_to_dev(disk);
|
|
struct request_queue *q = disk->queue;
|
|
|
|
if (WARN_ON(!q))
|
|
return -ENXIO;
|
|
|
|
/*
|
|
* SCSI probing may synchronously create and destroy a lot of
|
|
* request_queues for non-existent devices. Shutting down a fully
|
|
* functional queue takes measureable wallclock time as RCU grace
|
|
* periods are involved. To avoid excessive latency in these
|
|
* cases, a request_queue starts out in a degraded mode which is
|
|
* faster to shut down and is made fully functional here as
|
|
* request_queues for non-existent devices never get registered.
|
|
*/
|
|
if (!blk_queue_init_done(q)) {
|
|
queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
|
|
blk_queue_bypass_end(q);
|
|
if (q->mq_ops)
|
|
blk_mq_finish_init(q);
|
|
}
|
|
|
|
ret = blk_trace_init_sysfs(dev);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
|
|
if (ret < 0) {
|
|
blk_trace_remove_sysfs(dev);
|
|
return ret;
|
|
}
|
|
|
|
kobject_uevent(&q->kobj, KOBJ_ADD);
|
|
|
|
if (q->mq_ops)
|
|
blk_mq_register_disk(disk);
|
|
|
|
if (!q->request_fn)
|
|
return 0;
|
|
|
|
ret = elv_register_queue(q);
|
|
if (ret) {
|
|
kobject_uevent(&q->kobj, KOBJ_REMOVE);
|
|
kobject_del(&q->kobj);
|
|
blk_trace_remove_sysfs(dev);
|
|
kobject_put(&dev->kobj);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void blk_unregister_queue(struct gendisk *disk)
|
|
{
|
|
struct request_queue *q = disk->queue;
|
|
|
|
if (WARN_ON(!q))
|
|
return;
|
|
|
|
if (q->mq_ops)
|
|
blk_mq_unregister_disk(disk);
|
|
|
|
if (q->request_fn)
|
|
elv_unregister_queue(q);
|
|
|
|
kobject_uevent(&q->kobj, KOBJ_REMOVE);
|
|
kobject_del(&q->kobj);
|
|
blk_trace_remove_sysfs(disk_to_dev(disk));
|
|
kobject_put(&disk_to_dev(disk)->kobj);
|
|
}
|