2005-04-17 05:20:36 +07:00
|
|
|
/*
|
|
|
|
* Copyright (C) 2001 Sistina Software (UK) Limited.
|
dm table: rework reference counting
Rework table reference counting.
The existing code uses a reference counter. When the last reference is
dropped and the counter reaches zero, the table destructor is called.
Table reference counters are acquired/released from upcalls from other
kernel code (dm_any_congested, dm_merge_bvec, dm_unplug_all).
If the reference counter reaches zero in one of the upcalls, the table
destructor is called from almost random kernel code.
This leads to various problems:
* dm_any_congested being called under a spinlock, which calls the
destructor, which calls some sleeping function.
* the destructor attempting to take a lock that is already taken by the
same process.
* stale reference from some other kernel code keeps the table
constructed, which keeps some devices open, even after successful
return from "dmsetup remove". This can confuse lvm and prevent closing
of underlying devices or reusing device minor numbers.
The patch changes reference counting so that the table destructor can be
called only at predetermined places.
The table has always exactly one reference from either mapped_device->map
or hash_cell->new_map. After this patch, this reference is not counted
in table->holders. A pair of dm_create_table/dm_destroy_table functions
is used for table creation/destruction.
Temporary references from the other code increase table->holders. A pair
of dm_table_get/dm_table_put functions is used to manipulate it.
When the table is about to be destroyed, we wait for table->holders to
reach 0. Then, we call the table destructor. We use active waiting with
msleep(1), because the situation happens rarely (to one user in 5 years)
and removing the device isn't performance-critical task: the user doesn't
care if it takes one tick more or not.
This way, the destructor is called only at specific points
(dm_table_destroy function) and the above problems associated with lazy
destruction can't happen.
Finally remove the temporary protection added to dm_any_congested().
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-01-06 10:05:10 +07:00
|
|
|
* Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
|
2005-04-17 05:20:36 +07:00
|
|
|
*
|
|
|
|
* This file is released under the GPL.
|
|
|
|
*/
|
|
|
|
|
|
|
|
#include "dm.h"
|
|
|
|
|
|
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/vmalloc.h>
|
|
|
|
#include <linux/blkdev.h>
|
|
|
|
#include <linux/namei.h>
|
|
|
|
#include <linux/ctype.h>
|
2009-12-15 09:01:06 +07:00
|
|
|
#include <linux/string.h>
|
2005-04-17 05:20:36 +07:00
|
|
|
#include <linux/slab.h>
|
|
|
|
#include <linux/interrupt.h>
|
2006-03-27 16:18:20 +07:00
|
|
|
#include <linux/mutex.h>
|
dm table: rework reference counting
Rework table reference counting.
The existing code uses a reference counter. When the last reference is
dropped and the counter reaches zero, the table destructor is called.
Table reference counters are acquired/released from upcalls from other
kernel code (dm_any_congested, dm_merge_bvec, dm_unplug_all).
If the reference counter reaches zero in one of the upcalls, the table
destructor is called from almost random kernel code.
This leads to various problems:
* dm_any_congested being called under a spinlock, which calls the
destructor, which calls some sleeping function.
* the destructor attempting to take a lock that is already taken by the
same process.
* stale reference from some other kernel code keeps the table
constructed, which keeps some devices open, even after successful
return from "dmsetup remove". This can confuse lvm and prevent closing
of underlying devices or reusing device minor numbers.
The patch changes reference counting so that the table destructor can be
called only at predetermined places.
The table has always exactly one reference from either mapped_device->map
or hash_cell->new_map. After this patch, this reference is not counted
in table->holders. A pair of dm_create_table/dm_destroy_table functions
is used for table creation/destruction.
Temporary references from the other code increase table->holders. A pair
of dm_table_get/dm_table_put functions is used to manipulate it.
When the table is about to be destroyed, we wait for table->holders to
reach 0. Then, we call the table destructor. We use active waiting with
msleep(1), because the situation happens rarely (to one user in 5 years)
and removing the device isn't performance-critical task: the user doesn't
care if it takes one tick more or not.
This way, the destructor is called only at specific points
(dm_table_destroy function) and the above problems associated with lazy
destruction can't happen.
Finally remove the temporary protection added to dm_any_congested().
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-01-06 10:05:10 +07:00
|
|
|
#include <linux/delay.h>
|
2011-07-27 06:09:06 +07:00
|
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|
#include <linux/atomic.h>
|
2005-04-17 05:20:36 +07:00
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|
2006-06-26 14:27:35 +07:00
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|
#define DM_MSG_PREFIX "table"
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|
2005-04-17 05:20:36 +07:00
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#define MAX_DEPTH 16
|
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#define NODE_SIZE L1_CACHE_BYTES
|
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#define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
|
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|
#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
|
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struct dm_table {
|
2006-03-27 16:17:54 +07:00
|
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|
struct mapped_device *md;
|
dm: enable request based option
This patch enables request-based dm.
o Request-based dm and bio-based dm coexist, since there are
some target drivers which are more fitting to bio-based dm.
Also, there are other bio-based devices in the kernel
(e.g. md, loop).
Since bio-based device can't receive struct request,
there are some limitations on device stacking between
bio-based and request-based.
type of underlying device
bio-based request-based
----------------------------------------------
bio-based OK OK
request-based -- OK
The device type is recognized by the queue flag in the kernel,
so dm follows that.
o The type of a dm device is decided at the first table binding time.
Once the type of a dm device is decided, the type can't be changed.
o Mempool allocations are deferred to at the table loading time, since
mempools for request-based dm are different from those for bio-based
dm and needed mempool type is fixed by the type of table.
o Currently, request-based dm supports only tables that have a single
target. To support multiple targets, we need to support request
splitting or prevent bio/request from spanning multiple targets.
The former needs lots of changes in the block layer, and the latter
needs that all target drivers support merge() function.
Both will take a time.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:36 +07:00
|
|
|
unsigned type;
|
2005-04-17 05:20:36 +07:00
|
|
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|
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|
/* btree table */
|
|
|
|
unsigned int depth;
|
|
|
|
unsigned int counts[MAX_DEPTH]; /* in nodes */
|
|
|
|
sector_t *index[MAX_DEPTH];
|
|
|
|
|
|
|
|
unsigned int num_targets;
|
|
|
|
unsigned int num_allocated;
|
|
|
|
sector_t *highs;
|
|
|
|
struct dm_target *targets;
|
|
|
|
|
2011-11-01 03:19:04 +07:00
|
|
|
struct target_type *immutable_target_type;
|
2011-03-17 17:11:05 +07:00
|
|
|
unsigned integrity_supported:1;
|
2011-11-01 03:19:00 +07:00
|
|
|
unsigned singleton:1;
|
2010-08-12 10:14:08 +07:00
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|
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|
2005-04-17 05:20:36 +07:00
|
|
|
/*
|
|
|
|
* Indicates the rw permissions for the new logical
|
|
|
|
* device. This should be a combination of FMODE_READ
|
|
|
|
* and FMODE_WRITE.
|
|
|
|
*/
|
2008-09-03 02:28:45 +07:00
|
|
|
fmode_t mode;
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
/* a list of devices used by this table */
|
|
|
|
struct list_head devices;
|
|
|
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|
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/* events get handed up using this callback */
|
|
|
|
void (*event_fn)(void *);
|
|
|
|
void *event_context;
|
dm: enable request based option
This patch enables request-based dm.
o Request-based dm and bio-based dm coexist, since there are
some target drivers which are more fitting to bio-based dm.
Also, there are other bio-based devices in the kernel
(e.g. md, loop).
Since bio-based device can't receive struct request,
there are some limitations on device stacking between
bio-based and request-based.
type of underlying device
bio-based request-based
----------------------------------------------
bio-based OK OK
request-based -- OK
The device type is recognized by the queue flag in the kernel,
so dm follows that.
o The type of a dm device is decided at the first table binding time.
Once the type of a dm device is decided, the type can't be changed.
o Mempool allocations are deferred to at the table loading time, since
mempools for request-based dm are different from those for bio-based
dm and needed mempool type is fixed by the type of table.
o Currently, request-based dm supports only tables that have a single
target. To support multiple targets, we need to support request
splitting or prevent bio/request from spanning multiple targets.
The former needs lots of changes in the block layer, and the latter
needs that all target drivers support merge() function.
Both will take a time.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:36 +07:00
|
|
|
|
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|
struct dm_md_mempools *mempools;
|
2011-01-14 03:00:01 +07:00
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struct list_head target_callbacks;
|
2005-04-17 05:20:36 +07:00
|
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|
};
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|
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|
|
/*
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|
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|
* Similar to ceiling(log_size(n))
|
|
|
|
*/
|
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|
static unsigned int int_log(unsigned int n, unsigned int base)
|
|
|
|
{
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|
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|
int result = 0;
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|
while (n > 1) {
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n = dm_div_up(n, base);
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|
result++;
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|
}
|
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|
return result;
|
|
|
|
}
|
|
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|
|
|
|
|
/*
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|
* Calculate the index of the child node of the n'th node k'th key.
|
|
|
|
*/
|
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|
static inline unsigned int get_child(unsigned int n, unsigned int k)
|
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|
|
{
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|
return (n * CHILDREN_PER_NODE) + k;
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|
|
|
}
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/*
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* Return the n'th node of level l from table t.
|
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|
*/
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static inline sector_t *get_node(struct dm_table *t,
|
|
|
|
unsigned int l, unsigned int n)
|
|
|
|
{
|
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|
return t->index[l] + (n * KEYS_PER_NODE);
|
|
|
|
}
|
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|
|
/*
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|
|
* Return the highest key that you could lookup from the n'th
|
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|
* node on level l of the btree.
|
|
|
|
*/
|
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static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
|
|
|
|
{
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|
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|
for (; l < t->depth - 1; l++)
|
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|
n = get_child(n, CHILDREN_PER_NODE - 1);
|
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|
if (n >= t->counts[l])
|
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|
|
return (sector_t) - 1;
|
|
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|
|
return get_node(t, l, n)[KEYS_PER_NODE - 1];
|
|
|
|
}
|
|
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|
|
|
/*
|
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|
* Fills in a level of the btree based on the highs of the level
|
|
|
|
* below it.
|
|
|
|
*/
|
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|
static int setup_btree_index(unsigned int l, struct dm_table *t)
|
|
|
|
{
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|
unsigned int n, k;
|
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|
sector_t *node;
|
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|
for (n = 0U; n < t->counts[l]; n++) {
|
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node = get_node(t, l, n);
|
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for (k = 0U; k < KEYS_PER_NODE; k++)
|
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node[k] = high(t, l + 1, get_child(n, k));
|
|
|
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}
|
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|
return 0;
|
|
|
|
}
|
|
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|
|
void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
|
|
|
|
{
|
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|
unsigned long size;
|
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void *addr;
|
|
|
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|
|
/*
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|
* Check that we're not going to overflow.
|
|
|
|
*/
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|
if (nmemb > (ULONG_MAX / elem_size))
|
|
|
|
return NULL;
|
|
|
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|
size = nmemb * elem_size;
|
2011-08-02 18:32:02 +07:00
|
|
|
addr = vzalloc(size);
|
2005-04-17 05:20:36 +07:00
|
|
|
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|
|
return addr;
|
|
|
|
}
|
2011-08-02 18:32:04 +07:00
|
|
|
EXPORT_SYMBOL(dm_vcalloc);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
/*
|
|
|
|
* highs, and targets are managed as dynamic arrays during a
|
|
|
|
* table load.
|
|
|
|
*/
|
|
|
|
static int alloc_targets(struct dm_table *t, unsigned int num)
|
|
|
|
{
|
|
|
|
sector_t *n_highs;
|
|
|
|
struct dm_target *n_targets;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Allocate both the target array and offset array at once.
|
2007-12-13 21:15:25 +07:00
|
|
|
* Append an empty entry to catch sectors beyond the end of
|
|
|
|
* the device.
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
2007-12-13 21:15:25 +07:00
|
|
|
n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
|
2005-04-17 05:20:36 +07:00
|
|
|
sizeof(sector_t));
|
|
|
|
if (!n_highs)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
n_targets = (struct dm_target *) (n_highs + num);
|
|
|
|
|
dm table: remove unused buggy code that extends the targets array
A device mapper table is allocated in the following way:
* The function dm_table_create is called, it gets the number of targets
as an argument -- it allocates a targets array accordingly.
* For each target, we call dm_table_add_target.
If we add more targets than were specified in dm_table_create, the
function dm_table_add_target reallocates the targets array. However,
this reallocation code is wrong - it moves the targets array to a new
location, while some target constructors hold pointers to the array in
the old location.
The following DM target drivers save the pointer to the target
structure, so they corrupt memory if the target array is moved:
multipath, raid, mirror, snapshot, stripe, switch, thin, verity.
Under normal circumstances, the reallocation function is not called
(because dm_table_create is called with the correct number of targets),
so the buggy reallocation code is not used.
Prior to the fix "dm table: fail dm_table_create on dm_round_up
overflow", the reallocation code could only be used in case the user
specifies too large a value in param->target_count, such as 0xffffffff.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-23 07:51:39 +07:00
|
|
|
memset(n_highs, -1, sizeof(*n_highs) * num);
|
2005-04-17 05:20:36 +07:00
|
|
|
vfree(t->highs);
|
|
|
|
|
|
|
|
t->num_allocated = num;
|
|
|
|
t->highs = n_highs;
|
|
|
|
t->targets = n_targets;
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2008-09-03 02:28:45 +07:00
|
|
|
int dm_table_create(struct dm_table **result, fmode_t mode,
|
2006-03-27 16:17:54 +07:00
|
|
|
unsigned num_targets, struct mapped_device *md)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
2007-10-20 04:38:51 +07:00
|
|
|
struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
if (!t)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
INIT_LIST_HEAD(&t->devices);
|
2011-01-14 03:00:01 +07:00
|
|
|
INIT_LIST_HEAD(&t->target_callbacks);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
if (!num_targets)
|
|
|
|
num_targets = KEYS_PER_NODE;
|
|
|
|
|
|
|
|
num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
|
|
|
|
|
2013-11-23 07:52:06 +07:00
|
|
|
if (!num_targets) {
|
|
|
|
kfree(t);
|
|
|
|
return -ENOMEM;
|
|
|
|
}
|
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
if (alloc_targets(t, num_targets)) {
|
|
|
|
kfree(t);
|
|
|
|
return -ENOMEM;
|
|
|
|
}
|
|
|
|
|
|
|
|
t->mode = mode;
|
2006-03-27 16:17:54 +07:00
|
|
|
t->md = md;
|
2005-04-17 05:20:36 +07:00
|
|
|
*result = t;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void free_devices(struct list_head *devices)
|
|
|
|
{
|
|
|
|
struct list_head *tmp, *next;
|
|
|
|
|
2008-02-08 09:09:59 +07:00
|
|
|
list_for_each_safe(tmp, next, devices) {
|
2008-10-10 19:37:09 +07:00
|
|
|
struct dm_dev_internal *dd =
|
|
|
|
list_entry(tmp, struct dm_dev_internal, list);
|
2009-06-22 16:12:29 +07:00
|
|
|
DMWARN("dm_table_destroy: dm_put_device call missing for %s",
|
|
|
|
dd->dm_dev.name);
|
2005-04-17 05:20:36 +07:00
|
|
|
kfree(dd);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
dm table: rework reference counting
Rework table reference counting.
The existing code uses a reference counter. When the last reference is
dropped and the counter reaches zero, the table destructor is called.
Table reference counters are acquired/released from upcalls from other
kernel code (dm_any_congested, dm_merge_bvec, dm_unplug_all).
If the reference counter reaches zero in one of the upcalls, the table
destructor is called from almost random kernel code.
This leads to various problems:
* dm_any_congested being called under a spinlock, which calls the
destructor, which calls some sleeping function.
* the destructor attempting to take a lock that is already taken by the
same process.
* stale reference from some other kernel code keeps the table
constructed, which keeps some devices open, even after successful
return from "dmsetup remove". This can confuse lvm and prevent closing
of underlying devices or reusing device minor numbers.
The patch changes reference counting so that the table destructor can be
called only at predetermined places.
The table has always exactly one reference from either mapped_device->map
or hash_cell->new_map. After this patch, this reference is not counted
in table->holders. A pair of dm_create_table/dm_destroy_table functions
is used for table creation/destruction.
Temporary references from the other code increase table->holders. A pair
of dm_table_get/dm_table_put functions is used to manipulate it.
When the table is about to be destroyed, we wait for table->holders to
reach 0. Then, we call the table destructor. We use active waiting with
msleep(1), because the situation happens rarely (to one user in 5 years)
and removing the device isn't performance-critical task: the user doesn't
care if it takes one tick more or not.
This way, the destructor is called only at specific points
(dm_table_destroy function) and the above problems associated with lazy
destruction can't happen.
Finally remove the temporary protection added to dm_any_congested().
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-01-06 10:05:10 +07:00
|
|
|
void dm_table_destroy(struct dm_table *t)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
|
|
|
unsigned int i;
|
|
|
|
|
2009-12-11 06:52:23 +07:00
|
|
|
if (!t)
|
|
|
|
return;
|
|
|
|
|
2010-08-12 10:14:03 +07:00
|
|
|
/* free the indexes */
|
2005-04-17 05:20:36 +07:00
|
|
|
if (t->depth >= 2)
|
|
|
|
vfree(t->index[t->depth - 2]);
|
|
|
|
|
|
|
|
/* free the targets */
|
|
|
|
for (i = 0; i < t->num_targets; i++) {
|
|
|
|
struct dm_target *tgt = t->targets + i;
|
|
|
|
|
|
|
|
if (tgt->type->dtr)
|
|
|
|
tgt->type->dtr(tgt);
|
|
|
|
|
|
|
|
dm_put_target_type(tgt->type);
|
|
|
|
}
|
|
|
|
|
|
|
|
vfree(t->highs);
|
|
|
|
|
|
|
|
/* free the device list */
|
2012-03-29 00:41:24 +07:00
|
|
|
free_devices(&t->devices);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
dm: enable request based option
This patch enables request-based dm.
o Request-based dm and bio-based dm coexist, since there are
some target drivers which are more fitting to bio-based dm.
Also, there are other bio-based devices in the kernel
(e.g. md, loop).
Since bio-based device can't receive struct request,
there are some limitations on device stacking between
bio-based and request-based.
type of underlying device
bio-based request-based
----------------------------------------------
bio-based OK OK
request-based -- OK
The device type is recognized by the queue flag in the kernel,
so dm follows that.
o The type of a dm device is decided at the first table binding time.
Once the type of a dm device is decided, the type can't be changed.
o Mempool allocations are deferred to at the table loading time, since
mempools for request-based dm are different from those for bio-based
dm and needed mempool type is fixed by the type of table.
o Currently, request-based dm supports only tables that have a single
target. To support multiple targets, we need to support request
splitting or prevent bio/request from spanning multiple targets.
The former needs lots of changes in the block layer, and the latter
needs that all target drivers support merge() function.
Both will take a time.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:36 +07:00
|
|
|
dm_free_md_mempools(t->mempools);
|
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
kfree(t);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* See if we've already got a device in the list.
|
|
|
|
*/
|
2008-10-10 19:37:09 +07:00
|
|
|
static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
2008-10-10 19:37:09 +07:00
|
|
|
struct dm_dev_internal *dd;
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
list_for_each_entry (dd, l, list)
|
2008-10-10 19:37:09 +07:00
|
|
|
if (dd->dm_dev.bdev->bd_dev == dev)
|
2005-04-17 05:20:36 +07:00
|
|
|
return dd;
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Open a device so we can use it as a map destination.
|
|
|
|
*/
|
2008-10-10 19:37:09 +07:00
|
|
|
static int open_dev(struct dm_dev_internal *d, dev_t dev,
|
|
|
|
struct mapped_device *md)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
|
|
|
static char *_claim_ptr = "I belong to device-mapper";
|
|
|
|
struct block_device *bdev;
|
|
|
|
|
|
|
|
int r;
|
|
|
|
|
2008-10-10 19:37:09 +07:00
|
|
|
BUG_ON(d->dm_dev.bdev);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
2010-11-13 17:55:18 +07:00
|
|
|
bdev = blkdev_get_by_dev(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
|
2005-04-17 05:20:36 +07:00
|
|
|
if (IS_ERR(bdev))
|
|
|
|
return PTR_ERR(bdev);
|
2010-11-13 17:55:17 +07:00
|
|
|
|
|
|
|
r = bd_link_disk_holder(bdev, dm_disk(md));
|
|
|
|
if (r) {
|
block: make blkdev_get/put() handle exclusive access
Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.
* blkdev_get/put() are the primary open and close functions.
* bd_claim/release() deal with exclusive open.
* open/close_bdev_exclusive() are combination of open and claim and
the other way around, respectively.
* bd_link/unlink_disk_holder() to create and remove holder/slave
symlinks.
* open_by_devnum() wraps bdget() + blkdev_get().
The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access. Reorganize the interface such that,
* blkdev_get() is extended to include exclusive access management.
@holder argument is added and, if is @FMODE_EXCL specified, it will
gain exclusive access atomically w.r.t. other exclusive accesses.
* blkdev_put() is similarly extended. It now takes @mode argument and
if @FMODE_EXCL is set, it releases an exclusive access. Also, when
the last exclusive claim is released, the holder/slave symlinks are
removed automatically.
* bd_claim/release() and close_bdev_exclusive() are no longer
necessary and either made static or removed.
* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
is no longer necessary and removed.
* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
and blkdev_get(). It also has an unexpected extra bdev_read_only()
test which probably should be moved into blkdev_get().
* open_by_devnum() is modified to take @holder argument and pass it to
blkdev_get().
Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should). This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.
open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features. Well, let's leave them for another day.
Most conversions are straight-forward. drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 17:55:17 +07:00
|
|
|
blkdev_put(bdev, d->dm_dev.mode | FMODE_EXCL);
|
2010-11-13 17:55:17 +07:00
|
|
|
return r;
|
|
|
|
}
|
|
|
|
|
|
|
|
d->dm_dev.bdev = bdev;
|
|
|
|
return 0;
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Close a device that we've been using.
|
|
|
|
*/
|
2008-10-10 19:37:09 +07:00
|
|
|
static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
2008-10-10 19:37:09 +07:00
|
|
|
if (!d->dm_dev.bdev)
|
2005-04-17 05:20:36 +07:00
|
|
|
return;
|
|
|
|
|
2011-01-15 00:43:57 +07:00
|
|
|
bd_unlink_disk_holder(d->dm_dev.bdev, dm_disk(md));
|
block: make blkdev_get/put() handle exclusive access
Over time, block layer has accumulated a set of APIs dealing with bdev
open, close, claim and release.
* blkdev_get/put() are the primary open and close functions.
* bd_claim/release() deal with exclusive open.
* open/close_bdev_exclusive() are combination of open and claim and
the other way around, respectively.
* bd_link/unlink_disk_holder() to create and remove holder/slave
symlinks.
* open_by_devnum() wraps bdget() + blkdev_get().
The interface is a bit confusing and the decoupling of open and claim
makes it impossible to properly guarantee exclusive access as
in-kernel open + claim sequence can disturb the existing exclusive
open even before the block layer knows the current open if for another
exclusive access. Reorganize the interface such that,
* blkdev_get() is extended to include exclusive access management.
@holder argument is added and, if is @FMODE_EXCL specified, it will
gain exclusive access atomically w.r.t. other exclusive accesses.
* blkdev_put() is similarly extended. It now takes @mode argument and
if @FMODE_EXCL is set, it releases an exclusive access. Also, when
the last exclusive claim is released, the holder/slave symlinks are
removed automatically.
* bd_claim/release() and close_bdev_exclusive() are no longer
necessary and either made static or removed.
* bd_link_disk_holder() remains the same but bd_unlink_disk_holder()
is no longer necessary and removed.
* open_bdev_exclusive() becomes a simple wrapper around lookup_bdev()
and blkdev_get(). It also has an unexpected extra bdev_read_only()
test which probably should be moved into blkdev_get().
* open_by_devnum() is modified to take @holder argument and pass it to
blkdev_get().
Most of bdev open/close operations are unified into blkdev_get/put()
and most exclusive accesses are tested atomically at the open time (as
it should). This cleans up code and removes some, both valid and
invalid, but unnecessary all the same, corner cases.
open_bdev_exclusive() and open_by_devnum() can use further cleanup -
rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop
special features. Well, let's leave them for another day.
Most conversions are straight-forward. drbd conversion is a bit more
involved as there was some reordering, but the logic should stay the
same.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Peter Osterlund <petero2@telia.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: dm-devel@redhat.com
Cc: drbd-dev@lists.linbit.com
Cc: Leo Chen <leochen@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: Joern Engel <joern@logfs.org>
Cc: reiserfs-devel@vger.kernel.org
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 17:55:17 +07:00
|
|
|
blkdev_put(d->dm_dev.bdev, d->dm_dev.mode | FMODE_EXCL);
|
2008-10-10 19:37:09 +07:00
|
|
|
d->dm_dev.bdev = NULL;
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2009-09-05 02:40:22 +07:00
|
|
|
* If possible, this checks an area of a destination device is invalid.
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
2009-09-05 02:40:22 +07:00
|
|
|
static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
|
|
|
|
sector_t start, sector_t len, void *data)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
2011-05-29 19:02:52 +07:00
|
|
|
struct request_queue *q;
|
2009-06-22 16:12:34 +07:00
|
|
|
struct queue_limits *limits = data;
|
|
|
|
struct block_device *bdev = dev->bdev;
|
|
|
|
sector_t dev_size =
|
|
|
|
i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
|
2009-06-22 16:12:30 +07:00
|
|
|
unsigned short logical_block_size_sectors =
|
2009-06-22 16:12:34 +07:00
|
|
|
limits->logical_block_size >> SECTOR_SHIFT;
|
2009-06-22 16:12:30 +07:00
|
|
|
char b[BDEVNAME_SIZE];
|
2007-05-09 16:32:57 +07:00
|
|
|
|
2011-05-29 19:02:52 +07:00
|
|
|
/*
|
|
|
|
* Some devices exist without request functions,
|
|
|
|
* such as loop devices not yet bound to backing files.
|
|
|
|
* Forbid the use of such devices.
|
|
|
|
*/
|
|
|
|
q = bdev_get_queue(bdev);
|
|
|
|
if (!q || !q->make_request_fn) {
|
|
|
|
DMWARN("%s: %s is not yet initialised: "
|
|
|
|
"start=%llu, len=%llu, dev_size=%llu",
|
|
|
|
dm_device_name(ti->table->md), bdevname(bdev, b),
|
|
|
|
(unsigned long long)start,
|
|
|
|
(unsigned long long)len,
|
|
|
|
(unsigned long long)dev_size);
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
2007-05-09 16:32:57 +07:00
|
|
|
if (!dev_size)
|
2009-09-05 02:40:22 +07:00
|
|
|
return 0;
|
2007-05-09 16:32:57 +07:00
|
|
|
|
2009-07-24 02:30:42 +07:00
|
|
|
if ((start >= dev_size) || (start + len > dev_size)) {
|
2009-09-05 02:40:24 +07:00
|
|
|
DMWARN("%s: %s too small for target: "
|
|
|
|
"start=%llu, len=%llu, dev_size=%llu",
|
|
|
|
dm_device_name(ti->table->md), bdevname(bdev, b),
|
|
|
|
(unsigned long long)start,
|
|
|
|
(unsigned long long)len,
|
|
|
|
(unsigned long long)dev_size);
|
2009-09-05 02:40:22 +07:00
|
|
|
return 1;
|
2009-06-22 16:12:30 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
if (logical_block_size_sectors <= 1)
|
2009-09-05 02:40:22 +07:00
|
|
|
return 0;
|
2009-06-22 16:12:30 +07:00
|
|
|
|
|
|
|
if (start & (logical_block_size_sectors - 1)) {
|
|
|
|
DMWARN("%s: start=%llu not aligned to h/w "
|
2009-09-05 02:40:24 +07:00
|
|
|
"logical block size %u of %s",
|
2009-06-22 16:12:30 +07:00
|
|
|
dm_device_name(ti->table->md),
|
|
|
|
(unsigned long long)start,
|
2009-06-22 16:12:34 +07:00
|
|
|
limits->logical_block_size, bdevname(bdev, b));
|
2009-09-05 02:40:22 +07:00
|
|
|
return 1;
|
2009-06-22 16:12:30 +07:00
|
|
|
}
|
|
|
|
|
2009-07-24 02:30:42 +07:00
|
|
|
if (len & (logical_block_size_sectors - 1)) {
|
2009-06-22 16:12:30 +07:00
|
|
|
DMWARN("%s: len=%llu not aligned to h/w "
|
2009-09-05 02:40:24 +07:00
|
|
|
"logical block size %u of %s",
|
2009-06-22 16:12:30 +07:00
|
|
|
dm_device_name(ti->table->md),
|
2009-07-24 02:30:42 +07:00
|
|
|
(unsigned long long)len,
|
2009-06-22 16:12:34 +07:00
|
|
|
limits->logical_block_size, bdevname(bdev, b));
|
2009-09-05 02:40:22 +07:00
|
|
|
return 1;
|
2009-06-22 16:12:30 +07:00
|
|
|
}
|
|
|
|
|
2009-09-05 02:40:22 +07:00
|
|
|
return 0;
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
2009-04-03 01:55:28 +07:00
|
|
|
* This upgrades the mode on an already open dm_dev, being
|
2005-04-17 05:20:36 +07:00
|
|
|
* careful to leave things as they were if we fail to reopen the
|
2009-04-03 01:55:28 +07:00
|
|
|
* device and not to touch the existing bdev field in case
|
|
|
|
* it is accessed concurrently inside dm_table_any_congested().
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
2008-09-03 02:28:45 +07:00
|
|
|
static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
|
2008-10-10 19:37:09 +07:00
|
|
|
struct mapped_device *md)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
|
|
|
int r;
|
2009-04-03 01:55:28 +07:00
|
|
|
struct dm_dev_internal dd_new, dd_old;
|
2005-04-17 05:20:36 +07:00
|
|
|
|
2009-04-03 01:55:28 +07:00
|
|
|
dd_new = dd_old = *dd;
|
|
|
|
|
|
|
|
dd_new.dm_dev.mode |= new_mode;
|
|
|
|
dd_new.dm_dev.bdev = NULL;
|
|
|
|
|
|
|
|
r = open_dev(&dd_new, dd->dm_dev.bdev->bd_dev, md);
|
|
|
|
if (r)
|
|
|
|
return r;
|
2005-04-17 05:20:36 +07:00
|
|
|
|
2008-10-10 19:37:09 +07:00
|
|
|
dd->dm_dev.mode |= new_mode;
|
2009-04-03 01:55:28 +07:00
|
|
|
close_dev(&dd_old, md);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
2009-04-03 01:55:28 +07:00
|
|
|
return 0;
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Add a device to the list, or just increment the usage count if
|
|
|
|
* it's already present.
|
|
|
|
*/
|
2011-08-02 18:32:04 +07:00
|
|
|
int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
|
|
|
|
struct dm_dev **result)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
|
|
|
int r;
|
2008-02-08 09:10:14 +07:00
|
|
|
dev_t uninitialized_var(dev);
|
2008-10-10 19:37:09 +07:00
|
|
|
struct dm_dev_internal *dd;
|
2005-04-17 05:20:36 +07:00
|
|
|
unsigned int major, minor;
|
2011-08-02 18:32:04 +07:00
|
|
|
struct dm_table *t = ti->table;
|
dm: reject trailing characters in sccanf input
Device mapper uses sscanf to convert arguments to numbers. The problem is that
the way we use it ignores additional unmatched characters in the scanned string.
For example, this `if (sscanf(string, "%d", &number) == 1)' will match a number,
but also it will match number with some garbage appended, like "123abc".
As a result, device mapper accepts garbage after some numbers. For example
the command `dmsetup create vg1-new --table "0 16384 linear 254:1bla 34816bla"'
will pass without an error.
This patch fixes all sscanf uses in device mapper. It appends "%c" with
a pointer to a dummy character variable to every sscanf statement.
The construct `if (sscanf(string, "%d%c", &number, &dummy) == 1)' succeeds
only if string is a null-terminated number (optionally preceded by some
whitespace characters). If there is some character appended after the number,
sscanf matches "%c", writes the character to the dummy variable and returns 2.
We check the return value for 1 and consequently reject numbers with some
garbage appended.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-29 00:41:26 +07:00
|
|
|
char dummy;
|
2005-04-17 05:20:36 +07:00
|
|
|
|
2006-03-26 23:22:50 +07:00
|
|
|
BUG_ON(!t);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
dm: reject trailing characters in sccanf input
Device mapper uses sscanf to convert arguments to numbers. The problem is that
the way we use it ignores additional unmatched characters in the scanned string.
For example, this `if (sscanf(string, "%d", &number) == 1)' will match a number,
but also it will match number with some garbage appended, like "123abc".
As a result, device mapper accepts garbage after some numbers. For example
the command `dmsetup create vg1-new --table "0 16384 linear 254:1bla 34816bla"'
will pass without an error.
This patch fixes all sscanf uses in device mapper. It appends "%c" with
a pointer to a dummy character variable to every sscanf statement.
The construct `if (sscanf(string, "%d%c", &number, &dummy) == 1)' succeeds
only if string is a null-terminated number (optionally preceded by some
whitespace characters). If there is some character appended after the number,
sscanf matches "%c", writes the character to the dummy variable and returns 2.
We check the return value for 1 and consequently reject numbers with some
garbage appended.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-29 00:41:26 +07:00
|
|
|
if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
|
2005-04-17 05:20:36 +07:00
|
|
|
/* Extract the major/minor numbers */
|
|
|
|
dev = MKDEV(major, minor);
|
|
|
|
if (MAJOR(dev) != major || MINOR(dev) != minor)
|
|
|
|
return -EOVERFLOW;
|
|
|
|
} else {
|
|
|
|
/* convert the path to a device */
|
2008-08-11 05:24:08 +07:00
|
|
|
struct block_device *bdev = lookup_bdev(path);
|
|
|
|
|
|
|
|
if (IS_ERR(bdev))
|
|
|
|
return PTR_ERR(bdev);
|
|
|
|
dev = bdev->bd_dev;
|
|
|
|
bdput(bdev);
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
dd = find_device(&t->devices, dev);
|
|
|
|
if (!dd) {
|
|
|
|
dd = kmalloc(sizeof(*dd), GFP_KERNEL);
|
|
|
|
if (!dd)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
2008-10-10 19:37:09 +07:00
|
|
|
dd->dm_dev.mode = mode;
|
|
|
|
dd->dm_dev.bdev = NULL;
|
2005-04-17 05:20:36 +07:00
|
|
|
|
2006-03-27 16:17:59 +07:00
|
|
|
if ((r = open_dev(dd, dev, t->md))) {
|
2005-04-17 05:20:36 +07:00
|
|
|
kfree(dd);
|
|
|
|
return r;
|
|
|
|
}
|
|
|
|
|
2008-10-10 19:37:09 +07:00
|
|
|
format_dev_t(dd->dm_dev.name, dev);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
atomic_set(&dd->count, 0);
|
|
|
|
list_add(&dd->list, &t->devices);
|
|
|
|
|
2008-10-10 19:37:09 +07:00
|
|
|
} else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) {
|
2006-03-27 16:17:59 +07:00
|
|
|
r = upgrade_mode(dd, mode, t->md);
|
2005-04-17 05:20:36 +07:00
|
|
|
if (r)
|
|
|
|
return r;
|
|
|
|
}
|
|
|
|
atomic_inc(&dd->count);
|
|
|
|
|
2008-10-10 19:37:09 +07:00
|
|
|
*result = &dd->dm_dev;
|
2005-04-17 05:20:36 +07:00
|
|
|
return 0;
|
|
|
|
}
|
2011-08-02 18:32:04 +07:00
|
|
|
EXPORT_SYMBOL(dm_get_device);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
2014-06-03 21:30:28 +07:00
|
|
|
static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
|
|
|
|
sector_t start, sector_t len, void *data)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
2009-06-22 16:12:34 +07:00
|
|
|
struct queue_limits *limits = data;
|
|
|
|
struct block_device *bdev = dev->bdev;
|
2007-07-24 14:28:11 +07:00
|
|
|
struct request_queue *q = bdev_get_queue(bdev);
|
2008-10-10 19:37:13 +07:00
|
|
|
char b[BDEVNAME_SIZE];
|
|
|
|
|
|
|
|
if (unlikely(!q)) {
|
|
|
|
DMWARN("%s: Cannot set limits for nonexistent device %s",
|
|
|
|
dm_device_name(ti->table->md), bdevname(bdev, b));
|
2009-06-22 16:12:34 +07:00
|
|
|
return 0;
|
2008-10-10 19:37:13 +07:00
|
|
|
}
|
2006-10-03 15:15:42 +07:00
|
|
|
|
2010-01-11 15:21:50 +07:00
|
|
|
if (bdev_stack_limits(limits, bdev, start) < 0)
|
|
|
|
DMWARN("%s: adding target device %s caused an alignment inconsistency: "
|
2009-09-05 02:40:24 +07:00
|
|
|
"physical_block_size=%u, logical_block_size=%u, "
|
|
|
|
"alignment_offset=%u, start=%llu",
|
|
|
|
dm_device_name(ti->table->md), bdevname(bdev, b),
|
|
|
|
q->limits.physical_block_size,
|
|
|
|
q->limits.logical_block_size,
|
|
|
|
q->limits.alignment_offset,
|
2010-01-11 15:21:50 +07:00
|
|
|
(unsigned long long) start << SECTOR_SHIFT);
|
2006-10-03 15:15:42 +07:00
|
|
|
|
2008-07-21 18:00:39 +07:00
|
|
|
/*
|
|
|
|
* Check if merge fn is supported.
|
|
|
|
* If not we'll force DM to use PAGE_SIZE or
|
|
|
|
* smaller I/O, just to be safe.
|
2006-10-03 15:15:42 +07:00
|
|
|
*/
|
2011-08-02 18:32:04 +07:00
|
|
|
if (dm_queue_merge_is_compulsory(q) && !ti->type->merge)
|
2010-12-17 14:34:20 +07:00
|
|
|
blk_limits_max_hw_sectors(limits,
|
|
|
|
(unsigned int) (PAGE_SIZE >> 9));
|
2009-06-22 16:12:34 +07:00
|
|
|
return 0;
|
2006-10-03 15:15:42 +07:00
|
|
|
}
|
2006-03-27 16:17:49 +07:00
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
/*
|
2011-08-02 18:32:04 +07:00
|
|
|
* Decrement a device's use count and remove it if necessary.
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
2008-10-10 19:37:09 +07:00
|
|
|
void dm_put_device(struct dm_target *ti, struct dm_dev *d)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
2008-10-10 19:37:09 +07:00
|
|
|
struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal,
|
|
|
|
dm_dev);
|
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
if (atomic_dec_and_test(&dd->count)) {
|
2006-03-27 16:17:59 +07:00
|
|
|
close_dev(dd, ti->table->md);
|
2005-04-17 05:20:36 +07:00
|
|
|
list_del(&dd->list);
|
|
|
|
kfree(dd);
|
|
|
|
}
|
|
|
|
}
|
2011-08-02 18:32:04 +07:00
|
|
|
EXPORT_SYMBOL(dm_put_device);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Checks to see if the target joins onto the end of the table.
|
|
|
|
*/
|
|
|
|
static int adjoin(struct dm_table *table, struct dm_target *ti)
|
|
|
|
{
|
|
|
|
struct dm_target *prev;
|
|
|
|
|
|
|
|
if (!table->num_targets)
|
|
|
|
return !ti->begin;
|
|
|
|
|
|
|
|
prev = &table->targets[table->num_targets - 1];
|
|
|
|
return (ti->begin == (prev->begin + prev->len));
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Used to dynamically allocate the arg array.
|
2013-11-01 00:55:45 +07:00
|
|
|
*
|
|
|
|
* We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
|
|
|
|
* process messages even if some device is suspended. These messages have a
|
|
|
|
* small fixed number of arguments.
|
|
|
|
*
|
|
|
|
* On the other hand, dm-switch needs to process bulk data using messages and
|
|
|
|
* excessive use of GFP_NOIO could cause trouble.
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
|
|
|
static char **realloc_argv(unsigned *array_size, char **old_argv)
|
|
|
|
{
|
|
|
|
char **argv;
|
|
|
|
unsigned new_size;
|
2013-11-01 00:55:45 +07:00
|
|
|
gfp_t gfp;
|
2005-04-17 05:20:36 +07:00
|
|
|
|
2013-11-01 00:55:45 +07:00
|
|
|
if (*array_size) {
|
|
|
|
new_size = *array_size * 2;
|
|
|
|
gfp = GFP_KERNEL;
|
|
|
|
} else {
|
|
|
|
new_size = 8;
|
|
|
|
gfp = GFP_NOIO;
|
|
|
|
}
|
|
|
|
argv = kmalloc(new_size * sizeof(*argv), gfp);
|
2005-04-17 05:20:36 +07:00
|
|
|
if (argv) {
|
|
|
|
memcpy(argv, old_argv, *array_size * sizeof(*argv));
|
|
|
|
*array_size = new_size;
|
|
|
|
}
|
|
|
|
|
|
|
|
kfree(old_argv);
|
|
|
|
return argv;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Destructively splits up the argument list to pass to ctr.
|
|
|
|
*/
|
|
|
|
int dm_split_args(int *argc, char ***argvp, char *input)
|
|
|
|
{
|
|
|
|
char *start, *end = input, *out, **argv = NULL;
|
|
|
|
unsigned array_size = 0;
|
|
|
|
|
|
|
|
*argc = 0;
|
2006-06-26 14:27:31 +07:00
|
|
|
|
|
|
|
if (!input) {
|
|
|
|
*argvp = NULL;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
argv = realloc_argv(&array_size, argv);
|
|
|
|
if (!argv)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
while (1) {
|
|
|
|
/* Skip whitespace */
|
2009-12-15 09:01:06 +07:00
|
|
|
start = skip_spaces(end);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
if (!*start)
|
|
|
|
break; /* success, we hit the end */
|
|
|
|
|
|
|
|
/* 'out' is used to remove any back-quotes */
|
|
|
|
end = out = start;
|
|
|
|
while (*end) {
|
|
|
|
/* Everything apart from '\0' can be quoted */
|
|
|
|
if (*end == '\\' && *(end + 1)) {
|
|
|
|
*out++ = *(end + 1);
|
|
|
|
end += 2;
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (isspace(*end))
|
|
|
|
break; /* end of token */
|
|
|
|
|
|
|
|
*out++ = *end++;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* have we already filled the array ? */
|
|
|
|
if ((*argc + 1) > array_size) {
|
|
|
|
argv = realloc_argv(&array_size, argv);
|
|
|
|
if (!argv)
|
|
|
|
return -ENOMEM;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* we know this is whitespace */
|
|
|
|
if (*end)
|
|
|
|
end++;
|
|
|
|
|
|
|
|
/* terminate the string and put it in the array */
|
|
|
|
*out = '\0';
|
|
|
|
argv[*argc] = start;
|
|
|
|
(*argc)++;
|
|
|
|
}
|
|
|
|
|
|
|
|
*argvp = argv;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2009-06-22 16:12:31 +07:00
|
|
|
/*
|
|
|
|
* Impose necessary and sufficient conditions on a devices's table such
|
|
|
|
* that any incoming bio which respects its logical_block_size can be
|
|
|
|
* processed successfully. If it falls across the boundary between
|
|
|
|
* two or more targets, the size of each piece it gets split into must
|
|
|
|
* be compatible with the logical_block_size of the target processing it.
|
|
|
|
*/
|
2009-06-22 16:12:34 +07:00
|
|
|
static int validate_hardware_logical_block_alignment(struct dm_table *table,
|
|
|
|
struct queue_limits *limits)
|
2009-06-22 16:12:31 +07:00
|
|
|
{
|
|
|
|
/*
|
|
|
|
* This function uses arithmetic modulo the logical_block_size
|
|
|
|
* (in units of 512-byte sectors).
|
|
|
|
*/
|
|
|
|
unsigned short device_logical_block_size_sects =
|
2009-06-22 16:12:34 +07:00
|
|
|
limits->logical_block_size >> SECTOR_SHIFT;
|
2009-06-22 16:12:31 +07:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Offset of the start of the next table entry, mod logical_block_size.
|
|
|
|
*/
|
|
|
|
unsigned short next_target_start = 0;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Given an aligned bio that extends beyond the end of a
|
|
|
|
* target, how many sectors must the next target handle?
|
|
|
|
*/
|
|
|
|
unsigned short remaining = 0;
|
|
|
|
|
|
|
|
struct dm_target *uninitialized_var(ti);
|
2009-06-22 16:12:34 +07:00
|
|
|
struct queue_limits ti_limits;
|
2009-06-22 16:12:31 +07:00
|
|
|
unsigned i = 0;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Check each entry in the table in turn.
|
|
|
|
*/
|
|
|
|
while (i < dm_table_get_num_targets(table)) {
|
|
|
|
ti = dm_table_get_target(table, i++);
|
|
|
|
|
2012-01-11 22:27:11 +07:00
|
|
|
blk_set_stacking_limits(&ti_limits);
|
2009-06-22 16:12:34 +07:00
|
|
|
|
|
|
|
/* combine all target devices' limits */
|
|
|
|
if (ti->type->iterate_devices)
|
|
|
|
ti->type->iterate_devices(ti, dm_set_device_limits,
|
|
|
|
&ti_limits);
|
|
|
|
|
2009-06-22 16:12:31 +07:00
|
|
|
/*
|
|
|
|
* If the remaining sectors fall entirely within this
|
|
|
|
* table entry are they compatible with its logical_block_size?
|
|
|
|
*/
|
|
|
|
if (remaining < ti->len &&
|
2009-06-22 16:12:34 +07:00
|
|
|
remaining & ((ti_limits.logical_block_size >>
|
2009-06-22 16:12:31 +07:00
|
|
|
SECTOR_SHIFT) - 1))
|
|
|
|
break; /* Error */
|
|
|
|
|
|
|
|
next_target_start =
|
|
|
|
(unsigned short) ((next_target_start + ti->len) &
|
|
|
|
(device_logical_block_size_sects - 1));
|
|
|
|
remaining = next_target_start ?
|
|
|
|
device_logical_block_size_sects - next_target_start : 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (remaining) {
|
|
|
|
DMWARN("%s: table line %u (start sect %llu len %llu) "
|
2009-09-05 02:40:24 +07:00
|
|
|
"not aligned to h/w logical block size %u",
|
2009-06-22 16:12:31 +07:00
|
|
|
dm_device_name(table->md), i,
|
|
|
|
(unsigned long long) ti->begin,
|
|
|
|
(unsigned long long) ti->len,
|
2009-06-22 16:12:34 +07:00
|
|
|
limits->logical_block_size);
|
2009-06-22 16:12:31 +07:00
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
int dm_table_add_target(struct dm_table *t, const char *type,
|
|
|
|
sector_t start, sector_t len, char *params)
|
|
|
|
{
|
|
|
|
int r = -EINVAL, argc;
|
|
|
|
char **argv;
|
|
|
|
struct dm_target *tgt;
|
|
|
|
|
2011-11-01 03:19:00 +07:00
|
|
|
if (t->singleton) {
|
|
|
|
DMERR("%s: target type %s must appear alone in table",
|
|
|
|
dm_device_name(t->md), t->targets->type->name);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
dm table: remove unused buggy code that extends the targets array
A device mapper table is allocated in the following way:
* The function dm_table_create is called, it gets the number of targets
as an argument -- it allocates a targets array accordingly.
* For each target, we call dm_table_add_target.
If we add more targets than were specified in dm_table_create, the
function dm_table_add_target reallocates the targets array. However,
this reallocation code is wrong - it moves the targets array to a new
location, while some target constructors hold pointers to the array in
the old location.
The following DM target drivers save the pointer to the target
structure, so they corrupt memory if the target array is moved:
multipath, raid, mirror, snapshot, stripe, switch, thin, verity.
Under normal circumstances, the reallocation function is not called
(because dm_table_create is called with the correct number of targets),
so the buggy reallocation code is not used.
Prior to the fix "dm table: fail dm_table_create on dm_round_up
overflow", the reallocation code could only be used in case the user
specifies too large a value in param->target_count, such as 0xffffffff.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2013-11-23 07:51:39 +07:00
|
|
|
BUG_ON(t->num_targets >= t->num_allocated);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
tgt = t->targets + t->num_targets;
|
|
|
|
memset(tgt, 0, sizeof(*tgt));
|
|
|
|
|
|
|
|
if (!len) {
|
2006-06-26 14:27:35 +07:00
|
|
|
DMERR("%s: zero-length target", dm_device_name(t->md));
|
2005-04-17 05:20:36 +07:00
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
tgt->type = dm_get_target_type(type);
|
|
|
|
if (!tgt->type) {
|
2006-06-26 14:27:35 +07:00
|
|
|
DMERR("%s: %s: unknown target type", dm_device_name(t->md),
|
|
|
|
type);
|
2005-04-17 05:20:36 +07:00
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
2011-11-01 03:19:00 +07:00
|
|
|
if (dm_target_needs_singleton(tgt->type)) {
|
|
|
|
if (t->num_targets) {
|
|
|
|
DMERR("%s: target type %s must appear alone in table",
|
|
|
|
dm_device_name(t->md), type);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
t->singleton = 1;
|
|
|
|
}
|
|
|
|
|
2011-11-01 03:19:02 +07:00
|
|
|
if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
|
|
|
|
DMERR("%s: target type %s may not be included in read-only tables",
|
|
|
|
dm_device_name(t->md), type);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
2011-11-01 03:19:04 +07:00
|
|
|
if (t->immutable_target_type) {
|
|
|
|
if (t->immutable_target_type != tgt->type) {
|
|
|
|
DMERR("%s: immutable target type %s cannot be mixed with other target types",
|
|
|
|
dm_device_name(t->md), t->immutable_target_type->name);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
} else if (dm_target_is_immutable(tgt->type)) {
|
|
|
|
if (t->num_targets) {
|
|
|
|
DMERR("%s: immutable target type %s cannot be mixed with other target types",
|
|
|
|
dm_device_name(t->md), tgt->type->name);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
t->immutable_target_type = tgt->type;
|
|
|
|
}
|
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
tgt->table = t;
|
|
|
|
tgt->begin = start;
|
|
|
|
tgt->len = len;
|
|
|
|
tgt->error = "Unknown error";
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Does this target adjoin the previous one ?
|
|
|
|
*/
|
|
|
|
if (!adjoin(t, tgt)) {
|
|
|
|
tgt->error = "Gap in table";
|
|
|
|
r = -EINVAL;
|
|
|
|
goto bad;
|
|
|
|
}
|
|
|
|
|
|
|
|
r = dm_split_args(&argc, &argv, params);
|
|
|
|
if (r) {
|
|
|
|
tgt->error = "couldn't split parameters (insufficient memory)";
|
|
|
|
goto bad;
|
|
|
|
}
|
|
|
|
|
|
|
|
r = tgt->type->ctr(tgt, argc, argv);
|
|
|
|
kfree(argv);
|
|
|
|
if (r)
|
|
|
|
goto bad;
|
|
|
|
|
|
|
|
t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
|
|
|
|
|
2013-03-02 05:45:47 +07:00
|
|
|
if (!tgt->num_discard_bios && tgt->discards_supported)
|
|
|
|
DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
|
2011-08-02 18:32:01 +07:00
|
|
|
dm_device_name(t->md), type);
|
2010-08-12 10:14:08 +07:00
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
return 0;
|
|
|
|
|
|
|
|
bad:
|
2006-06-26 14:27:35 +07:00
|
|
|
DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
|
2005-04-17 05:20:36 +07:00
|
|
|
dm_put_target_type(tgt->type);
|
|
|
|
return r;
|
|
|
|
}
|
|
|
|
|
2011-08-02 18:32:04 +07:00
|
|
|
/*
|
|
|
|
* Target argument parsing helpers.
|
|
|
|
*/
|
|
|
|
static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
|
|
|
|
unsigned *value, char **error, unsigned grouped)
|
|
|
|
{
|
|
|
|
const char *arg_str = dm_shift_arg(arg_set);
|
dm: reject trailing characters in sccanf input
Device mapper uses sscanf to convert arguments to numbers. The problem is that
the way we use it ignores additional unmatched characters in the scanned string.
For example, this `if (sscanf(string, "%d", &number) == 1)' will match a number,
but also it will match number with some garbage appended, like "123abc".
As a result, device mapper accepts garbage after some numbers. For example
the command `dmsetup create vg1-new --table "0 16384 linear 254:1bla 34816bla"'
will pass without an error.
This patch fixes all sscanf uses in device mapper. It appends "%c" with
a pointer to a dummy character variable to every sscanf statement.
The construct `if (sscanf(string, "%d%c", &number, &dummy) == 1)' succeeds
only if string is a null-terminated number (optionally preceded by some
whitespace characters). If there is some character appended after the number,
sscanf matches "%c", writes the character to the dummy variable and returns 2.
We check the return value for 1 and consequently reject numbers with some
garbage appended.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-29 00:41:26 +07:00
|
|
|
char dummy;
|
2011-08-02 18:32:04 +07:00
|
|
|
|
|
|
|
if (!arg_str ||
|
dm: reject trailing characters in sccanf input
Device mapper uses sscanf to convert arguments to numbers. The problem is that
the way we use it ignores additional unmatched characters in the scanned string.
For example, this `if (sscanf(string, "%d", &number) == 1)' will match a number,
but also it will match number with some garbage appended, like "123abc".
As a result, device mapper accepts garbage after some numbers. For example
the command `dmsetup create vg1-new --table "0 16384 linear 254:1bla 34816bla"'
will pass without an error.
This patch fixes all sscanf uses in device mapper. It appends "%c" with
a pointer to a dummy character variable to every sscanf statement.
The construct `if (sscanf(string, "%d%c", &number, &dummy) == 1)' succeeds
only if string is a null-terminated number (optionally preceded by some
whitespace characters). If there is some character appended after the number,
sscanf matches "%c", writes the character to the dummy variable and returns 2.
We check the return value for 1 and consequently reject numbers with some
garbage appended.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-03-29 00:41:26 +07:00
|
|
|
(sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
|
2011-08-02 18:32:04 +07:00
|
|
|
(*value < arg->min) ||
|
|
|
|
(*value > arg->max) ||
|
|
|
|
(grouped && arg_set->argc < *value)) {
|
|
|
|
*error = arg->error;
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
|
|
|
|
unsigned *value, char **error)
|
|
|
|
{
|
|
|
|
return validate_next_arg(arg, arg_set, value, error, 0);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(dm_read_arg);
|
|
|
|
|
|
|
|
int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
|
|
|
|
unsigned *value, char **error)
|
|
|
|
{
|
|
|
|
return validate_next_arg(arg, arg_set, value, error, 1);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(dm_read_arg_group);
|
|
|
|
|
|
|
|
const char *dm_shift_arg(struct dm_arg_set *as)
|
|
|
|
{
|
|
|
|
char *r;
|
|
|
|
|
|
|
|
if (as->argc) {
|
|
|
|
as->argc--;
|
|
|
|
r = *as->argv;
|
|
|
|
as->argv++;
|
|
|
|
return r;
|
|
|
|
}
|
|
|
|
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(dm_shift_arg);
|
|
|
|
|
|
|
|
void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
|
|
|
|
{
|
|
|
|
BUG_ON(as->argc < num_args);
|
|
|
|
as->argc -= num_args;
|
|
|
|
as->argv += num_args;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(dm_consume_args);
|
|
|
|
|
2010-08-12 10:14:03 +07:00
|
|
|
static int dm_table_set_type(struct dm_table *t)
|
dm: enable request based option
This patch enables request-based dm.
o Request-based dm and bio-based dm coexist, since there are
some target drivers which are more fitting to bio-based dm.
Also, there are other bio-based devices in the kernel
(e.g. md, loop).
Since bio-based device can't receive struct request,
there are some limitations on device stacking between
bio-based and request-based.
type of underlying device
bio-based request-based
----------------------------------------------
bio-based OK OK
request-based -- OK
The device type is recognized by the queue flag in the kernel,
so dm follows that.
o The type of a dm device is decided at the first table binding time.
Once the type of a dm device is decided, the type can't be changed.
o Mempool allocations are deferred to at the table loading time, since
mempools for request-based dm are different from those for bio-based
dm and needed mempool type is fixed by the type of table.
o Currently, request-based dm supports only tables that have a single
target. To support multiple targets, we need to support request
splitting or prevent bio/request from spanning multiple targets.
The former needs lots of changes in the block layer, and the latter
needs that all target drivers support merge() function.
Both will take a time.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:36 +07:00
|
|
|
{
|
|
|
|
unsigned i;
|
2013-08-23 05:21:38 +07:00
|
|
|
unsigned bio_based = 0, request_based = 0, hybrid = 0;
|
dm: enable request based option
This patch enables request-based dm.
o Request-based dm and bio-based dm coexist, since there are
some target drivers which are more fitting to bio-based dm.
Also, there are other bio-based devices in the kernel
(e.g. md, loop).
Since bio-based device can't receive struct request,
there are some limitations on device stacking between
bio-based and request-based.
type of underlying device
bio-based request-based
----------------------------------------------
bio-based OK OK
request-based -- OK
The device type is recognized by the queue flag in the kernel,
so dm follows that.
o The type of a dm device is decided at the first table binding time.
Once the type of a dm device is decided, the type can't be changed.
o Mempool allocations are deferred to at the table loading time, since
mempools for request-based dm are different from those for bio-based
dm and needed mempool type is fixed by the type of table.
o Currently, request-based dm supports only tables that have a single
target. To support multiple targets, we need to support request
splitting or prevent bio/request from spanning multiple targets.
The former needs lots of changes in the block layer, and the latter
needs that all target drivers support merge() function.
Both will take a time.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:36 +07:00
|
|
|
struct dm_target *tgt;
|
|
|
|
struct dm_dev_internal *dd;
|
|
|
|
struct list_head *devices;
|
2013-08-23 05:21:38 +07:00
|
|
|
unsigned live_md_type;
|
dm: enable request based option
This patch enables request-based dm.
o Request-based dm and bio-based dm coexist, since there are
some target drivers which are more fitting to bio-based dm.
Also, there are other bio-based devices in the kernel
(e.g. md, loop).
Since bio-based device can't receive struct request,
there are some limitations on device stacking between
bio-based and request-based.
type of underlying device
bio-based request-based
----------------------------------------------
bio-based OK OK
request-based -- OK
The device type is recognized by the queue flag in the kernel,
so dm follows that.
o The type of a dm device is decided at the first table binding time.
Once the type of a dm device is decided, the type can't be changed.
o Mempool allocations are deferred to at the table loading time, since
mempools for request-based dm are different from those for bio-based
dm and needed mempool type is fixed by the type of table.
o Currently, request-based dm supports only tables that have a single
target. To support multiple targets, we need to support request
splitting or prevent bio/request from spanning multiple targets.
The former needs lots of changes in the block layer, and the latter
needs that all target drivers support merge() function.
Both will take a time.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:36 +07:00
|
|
|
|
|
|
|
for (i = 0; i < t->num_targets; i++) {
|
|
|
|
tgt = t->targets + i;
|
2013-08-23 05:21:38 +07:00
|
|
|
if (dm_target_hybrid(tgt))
|
|
|
|
hybrid = 1;
|
|
|
|
else if (dm_target_request_based(tgt))
|
dm: enable request based option
This patch enables request-based dm.
o Request-based dm and bio-based dm coexist, since there are
some target drivers which are more fitting to bio-based dm.
Also, there are other bio-based devices in the kernel
(e.g. md, loop).
Since bio-based device can't receive struct request,
there are some limitations on device stacking between
bio-based and request-based.
type of underlying device
bio-based request-based
----------------------------------------------
bio-based OK OK
request-based -- OK
The device type is recognized by the queue flag in the kernel,
so dm follows that.
o The type of a dm device is decided at the first table binding time.
Once the type of a dm device is decided, the type can't be changed.
o Mempool allocations are deferred to at the table loading time, since
mempools for request-based dm are different from those for bio-based
dm and needed mempool type is fixed by the type of table.
o Currently, request-based dm supports only tables that have a single
target. To support multiple targets, we need to support request
splitting or prevent bio/request from spanning multiple targets.
The former needs lots of changes in the block layer, and the latter
needs that all target drivers support merge() function.
Both will take a time.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:36 +07:00
|
|
|
request_based = 1;
|
|
|
|
else
|
|
|
|
bio_based = 1;
|
|
|
|
|
|
|
|
if (bio_based && request_based) {
|
|
|
|
DMWARN("Inconsistent table: different target types"
|
|
|
|
" can't be mixed up");
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2013-08-23 05:21:38 +07:00
|
|
|
if (hybrid && !bio_based && !request_based) {
|
|
|
|
/*
|
|
|
|
* The targets can work either way.
|
|
|
|
* Determine the type from the live device.
|
|
|
|
* Default to bio-based if device is new.
|
|
|
|
*/
|
|
|
|
live_md_type = dm_get_md_type(t->md);
|
|
|
|
if (live_md_type == DM_TYPE_REQUEST_BASED)
|
|
|
|
request_based = 1;
|
|
|
|
else
|
|
|
|
bio_based = 1;
|
|
|
|
}
|
|
|
|
|
dm: enable request based option
This patch enables request-based dm.
o Request-based dm and bio-based dm coexist, since there are
some target drivers which are more fitting to bio-based dm.
Also, there are other bio-based devices in the kernel
(e.g. md, loop).
Since bio-based device can't receive struct request,
there are some limitations on device stacking between
bio-based and request-based.
type of underlying device
bio-based request-based
----------------------------------------------
bio-based OK OK
request-based -- OK
The device type is recognized by the queue flag in the kernel,
so dm follows that.
o The type of a dm device is decided at the first table binding time.
Once the type of a dm device is decided, the type can't be changed.
o Mempool allocations are deferred to at the table loading time, since
mempools for request-based dm are different from those for bio-based
dm and needed mempool type is fixed by the type of table.
o Currently, request-based dm supports only tables that have a single
target. To support multiple targets, we need to support request
splitting or prevent bio/request from spanning multiple targets.
The former needs lots of changes in the block layer, and the latter
needs that all target drivers support merge() function.
Both will take a time.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:36 +07:00
|
|
|
if (bio_based) {
|
|
|
|
/* We must use this table as bio-based */
|
|
|
|
t->type = DM_TYPE_BIO_BASED;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
BUG_ON(!request_based); /* No targets in this table */
|
|
|
|
|
|
|
|
/* Non-request-stackable devices can't be used for request-based dm */
|
|
|
|
devices = dm_table_get_devices(t);
|
|
|
|
list_for_each_entry(dd, devices, list) {
|
|
|
|
if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) {
|
|
|
|
DMWARN("table load rejected: including"
|
|
|
|
" non-request-stackable devices");
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Request-based dm supports only tables that have a single target now.
|
|
|
|
* To support multiple targets, request splitting support is needed,
|
|
|
|
* and that needs lots of changes in the block-layer.
|
|
|
|
* (e.g. request completion process for partial completion.)
|
|
|
|
*/
|
|
|
|
if (t->num_targets > 1) {
|
|
|
|
DMWARN("Request-based dm doesn't support multiple targets yet");
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
|
|
|
t->type = DM_TYPE_REQUEST_BASED;
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
unsigned dm_table_get_type(struct dm_table *t)
|
|
|
|
{
|
|
|
|
return t->type;
|
|
|
|
}
|
|
|
|
|
2011-11-01 03:19:04 +07:00
|
|
|
struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
|
|
|
|
{
|
|
|
|
return t->immutable_target_type;
|
|
|
|
}
|
|
|
|
|
dm: enable request based option
This patch enables request-based dm.
o Request-based dm and bio-based dm coexist, since there are
some target drivers which are more fitting to bio-based dm.
Also, there are other bio-based devices in the kernel
(e.g. md, loop).
Since bio-based device can't receive struct request,
there are some limitations on device stacking between
bio-based and request-based.
type of underlying device
bio-based request-based
----------------------------------------------
bio-based OK OK
request-based -- OK
The device type is recognized by the queue flag in the kernel,
so dm follows that.
o The type of a dm device is decided at the first table binding time.
Once the type of a dm device is decided, the type can't be changed.
o Mempool allocations are deferred to at the table loading time, since
mempools for request-based dm are different from those for bio-based
dm and needed mempool type is fixed by the type of table.
o Currently, request-based dm supports only tables that have a single
target. To support multiple targets, we need to support request
splitting or prevent bio/request from spanning multiple targets.
The former needs lots of changes in the block layer, and the latter
needs that all target drivers support merge() function.
Both will take a time.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:36 +07:00
|
|
|
bool dm_table_request_based(struct dm_table *t)
|
|
|
|
{
|
|
|
|
return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
|
|
|
|
}
|
|
|
|
|
2014-02-14 01:43:32 +07:00
|
|
|
static int dm_table_alloc_md_mempools(struct dm_table *t)
|
dm: enable request based option
This patch enables request-based dm.
o Request-based dm and bio-based dm coexist, since there are
some target drivers which are more fitting to bio-based dm.
Also, there are other bio-based devices in the kernel
(e.g. md, loop).
Since bio-based device can't receive struct request,
there are some limitations on device stacking between
bio-based and request-based.
type of underlying device
bio-based request-based
----------------------------------------------
bio-based OK OK
request-based -- OK
The device type is recognized by the queue flag in the kernel,
so dm follows that.
o The type of a dm device is decided at the first table binding time.
Once the type of a dm device is decided, the type can't be changed.
o Mempool allocations are deferred to at the table loading time, since
mempools for request-based dm are different from those for bio-based
dm and needed mempool type is fixed by the type of table.
o Currently, request-based dm supports only tables that have a single
target. To support multiple targets, we need to support request
splitting or prevent bio/request from spanning multiple targets.
The former needs lots of changes in the block layer, and the latter
needs that all target drivers support merge() function.
Both will take a time.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:36 +07:00
|
|
|
{
|
|
|
|
unsigned type = dm_table_get_type(t);
|
2012-12-22 03:23:38 +07:00
|
|
|
unsigned per_bio_data_size = 0;
|
|
|
|
struct dm_target *tgt;
|
|
|
|
unsigned i;
|
dm: enable request based option
This patch enables request-based dm.
o Request-based dm and bio-based dm coexist, since there are
some target drivers which are more fitting to bio-based dm.
Also, there are other bio-based devices in the kernel
(e.g. md, loop).
Since bio-based device can't receive struct request,
there are some limitations on device stacking between
bio-based and request-based.
type of underlying device
bio-based request-based
----------------------------------------------
bio-based OK OK
request-based -- OK
The device type is recognized by the queue flag in the kernel,
so dm follows that.
o The type of a dm device is decided at the first table binding time.
Once the type of a dm device is decided, the type can't be changed.
o Mempool allocations are deferred to at the table loading time, since
mempools for request-based dm are different from those for bio-based
dm and needed mempool type is fixed by the type of table.
o Currently, request-based dm supports only tables that have a single
target. To support multiple targets, we need to support request
splitting or prevent bio/request from spanning multiple targets.
The former needs lots of changes in the block layer, and the latter
needs that all target drivers support merge() function.
Both will take a time.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:36 +07:00
|
|
|
|
|
|
|
if (unlikely(type == DM_TYPE_NONE)) {
|
|
|
|
DMWARN("no table type is set, can't allocate mempools");
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
|
|
|
|
2012-12-22 03:23:38 +07:00
|
|
|
if (type == DM_TYPE_BIO_BASED)
|
|
|
|
for (i = 0; i < t->num_targets; i++) {
|
|
|
|
tgt = t->targets + i;
|
|
|
|
per_bio_data_size = max(per_bio_data_size, tgt->per_bio_data_size);
|
|
|
|
}
|
|
|
|
|
|
|
|
t->mempools = dm_alloc_md_mempools(type, t->integrity_supported, per_bio_data_size);
|
dm: enable request based option
This patch enables request-based dm.
o Request-based dm and bio-based dm coexist, since there are
some target drivers which are more fitting to bio-based dm.
Also, there are other bio-based devices in the kernel
(e.g. md, loop).
Since bio-based device can't receive struct request,
there are some limitations on device stacking between
bio-based and request-based.
type of underlying device
bio-based request-based
----------------------------------------------
bio-based OK OK
request-based -- OK
The device type is recognized by the queue flag in the kernel,
so dm follows that.
o The type of a dm device is decided at the first table binding time.
Once the type of a dm device is decided, the type can't be changed.
o Mempool allocations are deferred to at the table loading time, since
mempools for request-based dm are different from those for bio-based
dm and needed mempool type is fixed by the type of table.
o Currently, request-based dm supports only tables that have a single
target. To support multiple targets, we need to support request
splitting or prevent bio/request from spanning multiple targets.
The former needs lots of changes in the block layer, and the latter
needs that all target drivers support merge() function.
Both will take a time.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:36 +07:00
|
|
|
if (!t->mempools)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
void dm_table_free_md_mempools(struct dm_table *t)
|
|
|
|
{
|
|
|
|
dm_free_md_mempools(t->mempools);
|
|
|
|
t->mempools = NULL;
|
|
|
|
}
|
|
|
|
|
|
|
|
struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
|
|
|
|
{
|
|
|
|
return t->mempools;
|
|
|
|
}
|
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
static int setup_indexes(struct dm_table *t)
|
|
|
|
{
|
|
|
|
int i;
|
|
|
|
unsigned int total = 0;
|
|
|
|
sector_t *indexes;
|
|
|
|
|
|
|
|
/* allocate the space for *all* the indexes */
|
|
|
|
for (i = t->depth - 2; i >= 0; i--) {
|
|
|
|
t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
|
|
|
|
total += t->counts[i];
|
|
|
|
}
|
|
|
|
|
|
|
|
indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
|
|
|
|
if (!indexes)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
/* set up internal nodes, bottom-up */
|
2008-02-08 09:10:04 +07:00
|
|
|
for (i = t->depth - 2; i >= 0; i--) {
|
2005-04-17 05:20:36 +07:00
|
|
|
t->index[i] = indexes;
|
|
|
|
indexes += (KEYS_PER_NODE * t->counts[i]);
|
|
|
|
setup_btree_index(i, t);
|
|
|
|
}
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Builds the btree to index the map.
|
|
|
|
*/
|
2010-08-12 10:14:03 +07:00
|
|
|
static int dm_table_build_index(struct dm_table *t)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
|
|
|
int r = 0;
|
|
|
|
unsigned int leaf_nodes;
|
|
|
|
|
|
|
|
/* how many indexes will the btree have ? */
|
|
|
|
leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
|
|
|
|
t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
|
|
|
|
|
|
|
|
/* leaf layer has already been set up */
|
|
|
|
t->counts[t->depth - 1] = leaf_nodes;
|
|
|
|
t->index[t->depth - 1] = t->highs;
|
|
|
|
|
|
|
|
if (t->depth >= 2)
|
|
|
|
r = setup_indexes(t);
|
|
|
|
|
|
|
|
return r;
|
|
|
|
}
|
|
|
|
|
2011-04-02 02:02:31 +07:00
|
|
|
/*
|
|
|
|
* Get a disk whose integrity profile reflects the table's profile.
|
|
|
|
* If %match_all is true, all devices' profiles must match.
|
|
|
|
* If %match_all is false, all devices must at least have an
|
|
|
|
* allocated integrity profile; but uninitialized is ok.
|
|
|
|
* Returns NULL if integrity support was inconsistent or unavailable.
|
|
|
|
*/
|
|
|
|
static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
|
|
|
|
bool match_all)
|
|
|
|
{
|
|
|
|
struct list_head *devices = dm_table_get_devices(t);
|
|
|
|
struct dm_dev_internal *dd = NULL;
|
|
|
|
struct gendisk *prev_disk = NULL, *template_disk = NULL;
|
|
|
|
|
|
|
|
list_for_each_entry(dd, devices, list) {
|
|
|
|
template_disk = dd->dm_dev.bdev->bd_disk;
|
|
|
|
if (!blk_get_integrity(template_disk))
|
|
|
|
goto no_integrity;
|
|
|
|
if (!match_all && !blk_integrity_is_initialized(template_disk))
|
|
|
|
continue; /* skip uninitialized profiles */
|
|
|
|
else if (prev_disk &&
|
|
|
|
blk_integrity_compare(prev_disk, template_disk) < 0)
|
|
|
|
goto no_integrity;
|
|
|
|
prev_disk = template_disk;
|
|
|
|
}
|
|
|
|
|
|
|
|
return template_disk;
|
|
|
|
|
|
|
|
no_integrity:
|
|
|
|
if (prev_disk)
|
|
|
|
DMWARN("%s: integrity not set: %s and %s profile mismatch",
|
|
|
|
dm_device_name(t->md),
|
|
|
|
prev_disk->disk_name,
|
|
|
|
template_disk->disk_name);
|
|
|
|
return NULL;
|
|
|
|
}
|
|
|
|
|
2010-08-12 10:14:03 +07:00
|
|
|
/*
|
|
|
|
* Register the mapped device for blk_integrity support if
|
2011-04-02 02:02:31 +07:00
|
|
|
* the underlying devices have an integrity profile. But all devices
|
|
|
|
* may not have matching profiles (checking all devices isn't reliable
|
|
|
|
* during table load because this table may use other DM device(s) which
|
|
|
|
* must be resumed before they will have an initialized integity profile).
|
|
|
|
* Stacked DM devices force a 2 stage integrity profile validation:
|
|
|
|
* 1 - during load, validate all initialized integrity profiles match
|
|
|
|
* 2 - during resume, validate all integrity profiles match
|
2010-08-12 10:14:03 +07:00
|
|
|
*/
|
|
|
|
static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
|
|
|
|
{
|
2011-04-02 02:02:31 +07:00
|
|
|
struct gendisk *template_disk = NULL;
|
2010-08-12 10:14:03 +07:00
|
|
|
|
2011-04-02 02:02:31 +07:00
|
|
|
template_disk = dm_table_get_integrity_disk(t, false);
|
|
|
|
if (!template_disk)
|
|
|
|
return 0;
|
2010-08-12 10:14:03 +07:00
|
|
|
|
2011-04-02 02:02:31 +07:00
|
|
|
if (!blk_integrity_is_initialized(dm_disk(md))) {
|
|
|
|
t->integrity_supported = 1;
|
|
|
|
return blk_integrity_register(dm_disk(md), NULL);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If DM device already has an initalized integrity
|
|
|
|
* profile the new profile should not conflict.
|
|
|
|
*/
|
|
|
|
if (blk_integrity_is_initialized(template_disk) &&
|
|
|
|
blk_integrity_compare(dm_disk(md), template_disk) < 0) {
|
|
|
|
DMWARN("%s: conflict with existing integrity profile: "
|
|
|
|
"%s profile mismatch",
|
|
|
|
dm_device_name(t->md),
|
|
|
|
template_disk->disk_name);
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Preserve existing initialized integrity profile */
|
|
|
|
t->integrity_supported = 1;
|
2010-08-12 10:14:03 +07:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Prepares the table for use by building the indices,
|
|
|
|
* setting the type, and allocating mempools.
|
|
|
|
*/
|
|
|
|
int dm_table_complete(struct dm_table *t)
|
|
|
|
{
|
|
|
|
int r;
|
|
|
|
|
|
|
|
r = dm_table_set_type(t);
|
|
|
|
if (r) {
|
|
|
|
DMERR("unable to set table type");
|
|
|
|
return r;
|
|
|
|
}
|
|
|
|
|
|
|
|
r = dm_table_build_index(t);
|
|
|
|
if (r) {
|
|
|
|
DMERR("unable to build btrees");
|
|
|
|
return r;
|
|
|
|
}
|
|
|
|
|
|
|
|
r = dm_table_prealloc_integrity(t, t->md);
|
|
|
|
if (r) {
|
|
|
|
DMERR("could not register integrity profile.");
|
|
|
|
return r;
|
|
|
|
}
|
|
|
|
|
|
|
|
r = dm_table_alloc_md_mempools(t);
|
|
|
|
if (r)
|
|
|
|
DMERR("unable to allocate mempools");
|
|
|
|
|
|
|
|
return r;
|
|
|
|
}
|
|
|
|
|
2006-03-27 16:18:20 +07:00
|
|
|
static DEFINE_MUTEX(_event_lock);
|
2005-04-17 05:20:36 +07:00
|
|
|
void dm_table_event_callback(struct dm_table *t,
|
|
|
|
void (*fn)(void *), void *context)
|
|
|
|
{
|
2006-03-27 16:18:20 +07:00
|
|
|
mutex_lock(&_event_lock);
|
2005-04-17 05:20:36 +07:00
|
|
|
t->event_fn = fn;
|
|
|
|
t->event_context = context;
|
2006-03-27 16:18:20 +07:00
|
|
|
mutex_unlock(&_event_lock);
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
void dm_table_event(struct dm_table *t)
|
|
|
|
{
|
|
|
|
/*
|
|
|
|
* You can no longer call dm_table_event() from interrupt
|
|
|
|
* context, use a bottom half instead.
|
|
|
|
*/
|
|
|
|
BUG_ON(in_interrupt());
|
|
|
|
|
2006-03-27 16:18:20 +07:00
|
|
|
mutex_lock(&_event_lock);
|
2005-04-17 05:20:36 +07:00
|
|
|
if (t->event_fn)
|
|
|
|
t->event_fn(t->event_context);
|
2006-03-27 16:18:20 +07:00
|
|
|
mutex_unlock(&_event_lock);
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
2011-08-02 18:32:04 +07:00
|
|
|
EXPORT_SYMBOL(dm_table_event);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
sector_t dm_table_get_size(struct dm_table *t)
|
|
|
|
{
|
|
|
|
return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
|
|
|
|
}
|
2011-08-02 18:32:04 +07:00
|
|
|
EXPORT_SYMBOL(dm_table_get_size);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
|
|
|
|
{
|
2006-06-26 14:27:27 +07:00
|
|
|
if (index >= t->num_targets)
|
2005-04-17 05:20:36 +07:00
|
|
|
return NULL;
|
|
|
|
|
|
|
|
return t->targets + index;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Search the btree for the correct target.
|
2007-12-13 21:15:25 +07:00
|
|
|
*
|
|
|
|
* Caller should check returned pointer with dm_target_is_valid()
|
|
|
|
* to trap I/O beyond end of device.
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
|
|
|
struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
|
|
|
|
{
|
|
|
|
unsigned int l, n = 0, k = 0;
|
|
|
|
sector_t *node;
|
|
|
|
|
|
|
|
for (l = 0; l < t->depth; l++) {
|
|
|
|
n = get_child(n, k);
|
|
|
|
node = get_node(t, l, n);
|
|
|
|
|
|
|
|
for (k = 0; k < KEYS_PER_NODE; k++)
|
|
|
|
if (node[k] >= sector)
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
|
|
|
|
return &t->targets[(KEYS_PER_NODE * n) + k];
|
|
|
|
}
|
|
|
|
|
2012-09-27 05:45:45 +07:00
|
|
|
static int count_device(struct dm_target *ti, struct dm_dev *dev,
|
|
|
|
sector_t start, sector_t len, void *data)
|
|
|
|
{
|
|
|
|
unsigned *num_devices = data;
|
|
|
|
|
|
|
|
(*num_devices)++;
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Check whether a table has no data devices attached using each
|
|
|
|
* target's iterate_devices method.
|
|
|
|
* Returns false if the result is unknown because a target doesn't
|
|
|
|
* support iterate_devices.
|
|
|
|
*/
|
|
|
|
bool dm_table_has_no_data_devices(struct dm_table *table)
|
|
|
|
{
|
|
|
|
struct dm_target *uninitialized_var(ti);
|
|
|
|
unsigned i = 0, num_devices = 0;
|
|
|
|
|
|
|
|
while (i < dm_table_get_num_targets(table)) {
|
|
|
|
ti = dm_table_get_target(table, i++);
|
|
|
|
|
|
|
|
if (!ti->type->iterate_devices)
|
|
|
|
return false;
|
|
|
|
|
|
|
|
ti->type->iterate_devices(ti, count_device, &num_devices);
|
|
|
|
if (num_devices)
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
2009-06-22 16:12:34 +07:00
|
|
|
/*
|
|
|
|
* Establish the new table's queue_limits and validate them.
|
|
|
|
*/
|
|
|
|
int dm_calculate_queue_limits(struct dm_table *table,
|
|
|
|
struct queue_limits *limits)
|
|
|
|
{
|
|
|
|
struct dm_target *uninitialized_var(ti);
|
|
|
|
struct queue_limits ti_limits;
|
|
|
|
unsigned i = 0;
|
|
|
|
|
2012-01-11 22:27:11 +07:00
|
|
|
blk_set_stacking_limits(limits);
|
2009-06-22 16:12:34 +07:00
|
|
|
|
|
|
|
while (i < dm_table_get_num_targets(table)) {
|
2012-01-11 22:27:11 +07:00
|
|
|
blk_set_stacking_limits(&ti_limits);
|
2009-06-22 16:12:34 +07:00
|
|
|
|
|
|
|
ti = dm_table_get_target(table, i++);
|
|
|
|
|
|
|
|
if (!ti->type->iterate_devices)
|
|
|
|
goto combine_limits;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Combine queue limits of all the devices this target uses.
|
|
|
|
*/
|
|
|
|
ti->type->iterate_devices(ti, dm_set_device_limits,
|
|
|
|
&ti_limits);
|
|
|
|
|
2009-09-05 02:40:25 +07:00
|
|
|
/* Set I/O hints portion of queue limits */
|
|
|
|
if (ti->type->io_hints)
|
|
|
|
ti->type->io_hints(ti, &ti_limits);
|
|
|
|
|
2009-06-22 16:12:34 +07:00
|
|
|
/*
|
|
|
|
* Check each device area is consistent with the target's
|
|
|
|
* overall queue limits.
|
|
|
|
*/
|
2009-09-05 02:40:22 +07:00
|
|
|
if (ti->type->iterate_devices(ti, device_area_is_invalid,
|
|
|
|
&ti_limits))
|
2009-06-22 16:12:34 +07:00
|
|
|
return -EINVAL;
|
|
|
|
|
|
|
|
combine_limits:
|
|
|
|
/*
|
|
|
|
* Merge this target's queue limits into the overall limits
|
|
|
|
* for the table.
|
|
|
|
*/
|
|
|
|
if (blk_stack_limits(limits, &ti_limits, 0) < 0)
|
2010-01-11 15:21:50 +07:00
|
|
|
DMWARN("%s: adding target device "
|
2009-06-22 16:12:34 +07:00
|
|
|
"(start sect %llu len %llu) "
|
2010-01-11 15:21:50 +07:00
|
|
|
"caused an alignment inconsistency",
|
2009-06-22 16:12:34 +07:00
|
|
|
dm_device_name(table->md),
|
|
|
|
(unsigned long long) ti->begin,
|
|
|
|
(unsigned long long) ti->len);
|
|
|
|
}
|
|
|
|
|
|
|
|
return validate_hardware_logical_block_alignment(table, limits);
|
|
|
|
}
|
|
|
|
|
2009-04-09 06:27:12 +07:00
|
|
|
/*
|
|
|
|
* Set the integrity profile for this device if all devices used have
|
2011-04-02 02:02:31 +07:00
|
|
|
* matching profiles. We're quite deep in the resume path but still
|
|
|
|
* don't know if all devices (particularly DM devices this device
|
|
|
|
* may be stacked on) have matching profiles. Even if the profiles
|
|
|
|
* don't match we have no way to fail (to resume) at this point.
|
2009-04-09 06:27:12 +07:00
|
|
|
*/
|
|
|
|
static void dm_table_set_integrity(struct dm_table *t)
|
|
|
|
{
|
2011-04-02 02:02:31 +07:00
|
|
|
struct gendisk *template_disk = NULL;
|
2009-04-09 06:27:12 +07:00
|
|
|
|
|
|
|
if (!blk_get_integrity(dm_disk(t->md)))
|
|
|
|
return;
|
|
|
|
|
2011-04-02 02:02:31 +07:00
|
|
|
template_disk = dm_table_get_integrity_disk(t, true);
|
2011-09-26 05:26:17 +07:00
|
|
|
if (template_disk)
|
|
|
|
blk_integrity_register(dm_disk(t->md),
|
|
|
|
blk_get_integrity(template_disk));
|
|
|
|
else if (blk_integrity_is_initialized(dm_disk(t->md)))
|
2011-04-02 02:02:31 +07:00
|
|
|
DMWARN("%s: device no longer has a valid integrity profile",
|
|
|
|
dm_device_name(t->md));
|
2011-09-26 05:26:17 +07:00
|
|
|
else
|
|
|
|
DMWARN("%s: unable to establish an integrity profile",
|
|
|
|
dm_device_name(t->md));
|
2009-04-09 06:27:12 +07:00
|
|
|
}
|
|
|
|
|
2011-08-02 18:32:08 +07:00
|
|
|
static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
|
|
|
|
sector_t start, sector_t len, void *data)
|
|
|
|
{
|
|
|
|
unsigned flush = (*(unsigned *)data);
|
|
|
|
struct request_queue *q = bdev_get_queue(dev->bdev);
|
|
|
|
|
|
|
|
return q && (q->flush_flags & flush);
|
|
|
|
}
|
|
|
|
|
|
|
|
static bool dm_table_supports_flush(struct dm_table *t, unsigned flush)
|
|
|
|
{
|
|
|
|
struct dm_target *ti;
|
|
|
|
unsigned i = 0;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Require at least one underlying device to support flushes.
|
|
|
|
* t->devices includes internal dm devices such as mirror logs
|
|
|
|
* so we need to use iterate_devices here, which targets
|
|
|
|
* supporting flushes must provide.
|
|
|
|
*/
|
|
|
|
while (i < dm_table_get_num_targets(t)) {
|
|
|
|
ti = dm_table_get_target(t, i++);
|
|
|
|
|
2013-03-02 05:45:47 +07:00
|
|
|
if (!ti->num_flush_bios)
|
2011-08-02 18:32:08 +07:00
|
|
|
continue;
|
|
|
|
|
2012-07-27 21:08:07 +07:00
|
|
|
if (ti->flush_supported)
|
|
|
|
return 1;
|
|
|
|
|
2011-08-02 18:32:08 +07:00
|
|
|
if (ti->type->iterate_devices &&
|
|
|
|
ti->type->iterate_devices(ti, device_flush_capable, &flush))
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2011-09-26 05:26:21 +07:00
|
|
|
static bool dm_table_discard_zeroes_data(struct dm_table *t)
|
|
|
|
{
|
|
|
|
struct dm_target *ti;
|
|
|
|
unsigned i = 0;
|
|
|
|
|
|
|
|
/* Ensure that all targets supports discard_zeroes_data. */
|
|
|
|
while (i < dm_table_get_num_targets(t)) {
|
|
|
|
ti = dm_table_get_target(t, i++);
|
|
|
|
|
|
|
|
if (ti->discard_zeroes_data_unsupported)
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
2011-11-01 03:18:50 +07:00
|
|
|
static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
|
|
|
|
sector_t start, sector_t len, void *data)
|
|
|
|
{
|
|
|
|
struct request_queue *q = bdev_get_queue(dev->bdev);
|
|
|
|
|
|
|
|
return q && blk_queue_nonrot(q);
|
|
|
|
}
|
|
|
|
|
2012-09-27 05:45:43 +07:00
|
|
|
static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
|
|
|
|
sector_t start, sector_t len, void *data)
|
|
|
|
{
|
|
|
|
struct request_queue *q = bdev_get_queue(dev->bdev);
|
|
|
|
|
|
|
|
return q && !blk_queue_add_random(q);
|
|
|
|
}
|
|
|
|
|
|
|
|
static bool dm_table_all_devices_attribute(struct dm_table *t,
|
|
|
|
iterate_devices_callout_fn func)
|
2011-11-01 03:18:50 +07:00
|
|
|
{
|
|
|
|
struct dm_target *ti;
|
|
|
|
unsigned i = 0;
|
|
|
|
|
|
|
|
while (i < dm_table_get_num_targets(t)) {
|
|
|
|
ti = dm_table_get_target(t, i++);
|
|
|
|
|
|
|
|
if (!ti->type->iterate_devices ||
|
2012-09-27 05:45:43 +07:00
|
|
|
!ti->type->iterate_devices(ti, func, NULL))
|
2011-11-01 03:18:50 +07:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
2012-12-22 03:23:36 +07:00
|
|
|
static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
|
|
|
|
sector_t start, sector_t len, void *data)
|
|
|
|
{
|
|
|
|
struct request_queue *q = bdev_get_queue(dev->bdev);
|
|
|
|
|
|
|
|
return q && !q->limits.max_write_same_sectors;
|
|
|
|
}
|
|
|
|
|
|
|
|
static bool dm_table_supports_write_same(struct dm_table *t)
|
|
|
|
{
|
|
|
|
struct dm_target *ti;
|
|
|
|
unsigned i = 0;
|
|
|
|
|
|
|
|
while (i < dm_table_get_num_targets(t)) {
|
|
|
|
ti = dm_table_get_target(t, i++);
|
|
|
|
|
2013-03-02 05:45:47 +07:00
|
|
|
if (!ti->num_write_same_bios)
|
2012-12-22 03:23:36 +07:00
|
|
|
return false;
|
|
|
|
|
|
|
|
if (!ti->type->iterate_devices ||
|
2013-05-10 20:37:16 +07:00
|
|
|
ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
|
2012-12-22 03:23:36 +07:00
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
return true;
|
|
|
|
}
|
|
|
|
|
2009-06-22 16:12:34 +07:00
|
|
|
void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
|
|
|
|
struct queue_limits *limits)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
2011-08-02 18:32:08 +07:00
|
|
|
unsigned flush = 0;
|
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
/*
|
2009-06-22 16:12:32 +07:00
|
|
|
* Copy table's limits to the DM device's request_queue
|
2005-04-17 05:20:36 +07:00
|
|
|
*/
|
2009-06-22 16:12:34 +07:00
|
|
|
q->limits = *limits;
|
2008-04-30 00:12:35 +07:00
|
|
|
|
2010-08-12 10:14:08 +07:00
|
|
|
if (!dm_table_supports_discards(t))
|
|
|
|
queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
|
|
|
|
else
|
|
|
|
queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
|
|
|
|
|
2011-08-02 18:32:08 +07:00
|
|
|
if (dm_table_supports_flush(t, REQ_FLUSH)) {
|
|
|
|
flush |= REQ_FLUSH;
|
|
|
|
if (dm_table_supports_flush(t, REQ_FUA))
|
|
|
|
flush |= REQ_FUA;
|
|
|
|
}
|
|
|
|
blk_queue_flush(q, flush);
|
|
|
|
|
2011-09-26 05:26:21 +07:00
|
|
|
if (!dm_table_discard_zeroes_data(t))
|
|
|
|
q->limits.discard_zeroes_data = 0;
|
|
|
|
|
2012-09-27 05:45:43 +07:00
|
|
|
/* Ensure that all underlying devices are non-rotational. */
|
|
|
|
if (dm_table_all_devices_attribute(t, device_is_nonrot))
|
2011-11-01 03:18:50 +07:00
|
|
|
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
|
|
|
|
else
|
|
|
|
queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
|
|
|
|
|
2012-12-22 03:23:36 +07:00
|
|
|
if (!dm_table_supports_write_same(t))
|
|
|
|
q->limits.max_write_same_sectors = 0;
|
2012-12-22 03:23:30 +07:00
|
|
|
|
2009-04-09 06:27:12 +07:00
|
|
|
dm_table_set_integrity(t);
|
dm: enable request based option
This patch enables request-based dm.
o Request-based dm and bio-based dm coexist, since there are
some target drivers which are more fitting to bio-based dm.
Also, there are other bio-based devices in the kernel
(e.g. md, loop).
Since bio-based device can't receive struct request,
there are some limitations on device stacking between
bio-based and request-based.
type of underlying device
bio-based request-based
----------------------------------------------
bio-based OK OK
request-based -- OK
The device type is recognized by the queue flag in the kernel,
so dm follows that.
o The type of a dm device is decided at the first table binding time.
Once the type of a dm device is decided, the type can't be changed.
o Mempool allocations are deferred to at the table loading time, since
mempools for request-based dm are different from those for bio-based
dm and needed mempool type is fixed by the type of table.
o Currently, request-based dm supports only tables that have a single
target. To support multiple targets, we need to support request
splitting or prevent bio/request from spanning multiple targets.
The former needs lots of changes in the block layer, and the latter
needs that all target drivers support merge() function.
Both will take a time.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:36 +07:00
|
|
|
|
2012-09-27 05:45:43 +07:00
|
|
|
/*
|
|
|
|
* Determine whether or not this queue's I/O timings contribute
|
|
|
|
* to the entropy pool, Only request-based targets use this.
|
|
|
|
* Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
|
|
|
|
* have it set.
|
|
|
|
*/
|
|
|
|
if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
|
|
|
|
queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
|
|
|
|
|
dm: enable request based option
This patch enables request-based dm.
o Request-based dm and bio-based dm coexist, since there are
some target drivers which are more fitting to bio-based dm.
Also, there are other bio-based devices in the kernel
(e.g. md, loop).
Since bio-based device can't receive struct request,
there are some limitations on device stacking between
bio-based and request-based.
type of underlying device
bio-based request-based
----------------------------------------------
bio-based OK OK
request-based -- OK
The device type is recognized by the queue flag in the kernel,
so dm follows that.
o The type of a dm device is decided at the first table binding time.
Once the type of a dm device is decided, the type can't be changed.
o Mempool allocations are deferred to at the table loading time, since
mempools for request-based dm are different from those for bio-based
dm and needed mempool type is fixed by the type of table.
o Currently, request-based dm supports only tables that have a single
target. To support multiple targets, we need to support request
splitting or prevent bio/request from spanning multiple targets.
The former needs lots of changes in the block layer, and the latter
needs that all target drivers support merge() function.
Both will take a time.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:36 +07:00
|
|
|
/*
|
|
|
|
* QUEUE_FLAG_STACKABLE must be set after all queue settings are
|
|
|
|
* visible to other CPUs because, once the flag is set, incoming bios
|
|
|
|
* are processed by request-based dm, which refers to the queue
|
|
|
|
* settings.
|
|
|
|
* Until the flag set, bios are passed to bio-based dm and queued to
|
|
|
|
* md->deferred where queue settings are not needed yet.
|
|
|
|
* Those bios are passed to request-based dm at the resume time.
|
|
|
|
*/
|
|
|
|
smp_mb();
|
|
|
|
if (dm_table_request_based(t))
|
|
|
|
queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
unsigned int dm_table_get_num_targets(struct dm_table *t)
|
|
|
|
{
|
|
|
|
return t->num_targets;
|
|
|
|
}
|
|
|
|
|
|
|
|
struct list_head *dm_table_get_devices(struct dm_table *t)
|
|
|
|
{
|
|
|
|
return &t->devices;
|
|
|
|
}
|
|
|
|
|
2008-09-03 02:28:45 +07:00
|
|
|
fmode_t dm_table_get_mode(struct dm_table *t)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
|
|
|
return t->mode;
|
|
|
|
}
|
2011-08-02 18:32:04 +07:00
|
|
|
EXPORT_SYMBOL(dm_table_get_mode);
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
static void suspend_targets(struct dm_table *t, unsigned postsuspend)
|
|
|
|
{
|
|
|
|
int i = t->num_targets;
|
|
|
|
struct dm_target *ti = t->targets;
|
|
|
|
|
|
|
|
while (i--) {
|
|
|
|
if (postsuspend) {
|
|
|
|
if (ti->type->postsuspend)
|
|
|
|
ti->type->postsuspend(ti);
|
|
|
|
} else if (ti->type->presuspend)
|
|
|
|
ti->type->presuspend(ti);
|
|
|
|
|
|
|
|
ti++;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
void dm_table_presuspend_targets(struct dm_table *t)
|
|
|
|
{
|
2005-07-29 11:15:57 +07:00
|
|
|
if (!t)
|
|
|
|
return;
|
|
|
|
|
2008-04-25 04:10:51 +07:00
|
|
|
suspend_targets(t, 0);
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
|
|
|
void dm_table_postsuspend_targets(struct dm_table *t)
|
|
|
|
{
|
2005-07-29 11:15:57 +07:00
|
|
|
if (!t)
|
|
|
|
return;
|
|
|
|
|
2008-04-25 04:10:51 +07:00
|
|
|
suspend_targets(t, 1);
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
2006-10-03 15:15:36 +07:00
|
|
|
int dm_table_resume_targets(struct dm_table *t)
|
2005-04-17 05:20:36 +07:00
|
|
|
{
|
2006-10-03 15:15:36 +07:00
|
|
|
int i, r = 0;
|
|
|
|
|
|
|
|
for (i = 0; i < t->num_targets; i++) {
|
|
|
|
struct dm_target *ti = t->targets + i;
|
|
|
|
|
|
|
|
if (!ti->type->preresume)
|
|
|
|
continue;
|
|
|
|
|
|
|
|
r = ti->type->preresume(ti);
|
2013-10-25 01:10:29 +07:00
|
|
|
if (r) {
|
|
|
|
DMERR("%s: %s: preresume failed, error = %d",
|
|
|
|
dm_device_name(t->md), ti->type->name, r);
|
2006-10-03 15:15:36 +07:00
|
|
|
return r;
|
2013-10-25 01:10:29 +07:00
|
|
|
}
|
2006-10-03 15:15:36 +07:00
|
|
|
}
|
2005-04-17 05:20:36 +07:00
|
|
|
|
|
|
|
for (i = 0; i < t->num_targets; i++) {
|
|
|
|
struct dm_target *ti = t->targets + i;
|
|
|
|
|
|
|
|
if (ti->type->resume)
|
|
|
|
ti->type->resume(ti);
|
|
|
|
}
|
2006-10-03 15:15:36 +07:00
|
|
|
|
|
|
|
return 0;
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
2011-01-14 03:00:01 +07:00
|
|
|
void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
|
|
|
|
{
|
|
|
|
list_add(&cb->list, &t->target_callbacks);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
|
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
int dm_table_any_congested(struct dm_table *t, int bdi_bits)
|
|
|
|
{
|
2008-10-10 19:37:09 +07:00
|
|
|
struct dm_dev_internal *dd;
|
2008-02-08 09:09:59 +07:00
|
|
|
struct list_head *devices = dm_table_get_devices(t);
|
2011-01-14 03:00:01 +07:00
|
|
|
struct dm_target_callbacks *cb;
|
2005-04-17 05:20:36 +07:00
|
|
|
int r = 0;
|
|
|
|
|
2008-02-08 09:09:59 +07:00
|
|
|
list_for_each_entry(dd, devices, list) {
|
2008-10-10 19:37:09 +07:00
|
|
|
struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
|
2008-10-10 19:37:13 +07:00
|
|
|
char b[BDEVNAME_SIZE];
|
|
|
|
|
|
|
|
if (likely(q))
|
|
|
|
r |= bdi_congested(&q->backing_dev_info, bdi_bits);
|
|
|
|
else
|
|
|
|
DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
|
|
|
|
dm_device_name(t->md),
|
|
|
|
bdevname(dd->dm_dev.bdev, b));
|
2005-04-17 05:20:36 +07:00
|
|
|
}
|
|
|
|
|
2011-01-14 03:00:01 +07:00
|
|
|
list_for_each_entry(cb, &t->target_callbacks, list)
|
|
|
|
if (cb->congested_fn)
|
|
|
|
r |= cb->congested_fn(cb, bdi_bits);
|
|
|
|
|
2005-04-17 05:20:36 +07:00
|
|
|
return r;
|
|
|
|
}
|
|
|
|
|
dm: prepare for request based option
This patch adds core functions for request-based dm.
When struct mapped device (md) is initialized, md->queue has
an I/O scheduler and the following functions are used for
request-based dm as the queue functions:
make_request_fn: dm_make_request()
pref_fn: dm_prep_fn()
request_fn: dm_request_fn()
softirq_done_fn: dm_softirq_done()
lld_busy_fn: dm_lld_busy()
Actual initializations are done in another patch (PATCH 2).
Below is a brief summary of how request-based dm behaves, including:
- making request from bio
- cloning, mapping and dispatching request
- completing request and bio
- suspending md
- resuming md
bio to request
==============
md->queue->make_request_fn() (dm_make_request()) calls __make_request()
for a bio submitted to the md.
Then, the bio is kept in the queue as a new request or merged into
another request in the queue if possible.
Cloning and Mapping
===================
Cloning and mapping are done in md->queue->request_fn() (dm_request_fn()),
when requests are dispatched after they are sorted by the I/O scheduler.
dm_request_fn() checks busy state of underlying devices using
target's busy() function and stops dispatching requests to keep them
on the dm device's queue if busy.
It helps better I/O merging, since no merge is done for a request
once it is dispatched to underlying devices.
Actual cloning and mapping are done in dm_prep_fn() and map_request()
called from dm_request_fn().
dm_prep_fn() clones not only request but also bios of the request
so that dm can hold bio completion in error cases and prevent
the bio submitter from noticing the error.
(See the "Completion" section below for details.)
After the cloning, the clone is mapped by target's map_rq() function
and inserted to underlying device's queue using
blk_insert_cloned_request().
Completion
==========
Request completion can be hooked by rq->end_io(), but then, all bios
in the request will have been completed even error cases, and the bio
submitter will have noticed the error.
To prevent the bio completion in error cases, request-based dm clones
both bio and request and hooks both bio->bi_end_io() and rq->end_io():
bio->bi_end_io(): end_clone_bio()
rq->end_io(): end_clone_request()
Summary of the request completion flow is below:
blk_end_request() for a clone request
=> blk_update_request()
=> bio->bi_end_io() == end_clone_bio() for each clone bio
=> Free the clone bio
=> Success: Complete the original bio (blk_update_request())
Error: Don't complete the original bio
=> blk_finish_request()
=> rq->end_io() == end_clone_request()
=> blk_complete_request()
=> dm_softirq_done()
=> Free the clone request
=> Success: Complete the original request (blk_end_request())
Error: Requeue the original request
end_clone_bio() completes the original request on the size of
the original bio in successful cases.
Even if all bios in the original request are completed by that
completion, the original request must not be completed yet to keep
the ordering of request completion for the stacking.
So end_clone_bio() uses blk_update_request() instead of
blk_end_request().
In error cases, end_clone_bio() doesn't complete the original bio.
It just frees the cloned bio and gives over the error handling to
end_clone_request().
end_clone_request(), which is called with queue lock held, completes
the clone request and the original request in a softirq context
(dm_softirq_done()), which has no queue lock, to avoid a deadlock
issue on submission of another request during the completion:
- The submitted request may be mapped to the same device
- Request submission requires queue lock, but the queue lock
has been held by itself and it doesn't know that
The clone request has no clone bio when dm_softirq_done() is called.
So target drivers can't resubmit it again even error cases.
Instead, they can ask dm core for requeueing and remapping
the original request in that cases.
suspend
=======
Request-based dm uses stopping md->queue as suspend of the md.
For noflush suspend, just stops md->queue.
For flush suspend, inserts a marker request to the tail of md->queue.
And dispatches all requests in md->queue until the marker comes to
the front of md->queue. Then, stops dispatching request and waits
for the all dispatched requests to complete.
After that, completes the marker request, stops md->queue and
wake up the waiter on the suspend queue, md->wait.
resume
======
Starts md->queue.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-06-22 16:12:35 +07:00
|
|
|
int dm_table_any_busy_target(struct dm_table *t)
|
|
|
|
{
|
|
|
|
unsigned i;
|
|
|
|
struct dm_target *ti;
|
|
|
|
|
|
|
|
for (i = 0; i < t->num_targets; i++) {
|
|
|
|
ti = t->targets + i;
|
|
|
|
if (ti->type->busy && ti->type->busy(ti))
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2006-03-27 16:17:54 +07:00
|
|
|
struct mapped_device *dm_table_get_md(struct dm_table *t)
|
|
|
|
{
|
|
|
|
return t->md;
|
|
|
|
}
|
2011-08-02 18:32:04 +07:00
|
|
|
EXPORT_SYMBOL(dm_table_get_md);
|
2006-03-27 16:17:54 +07:00
|
|
|
|
2014-02-28 21:33:43 +07:00
|
|
|
void dm_table_run_md_queue_async(struct dm_table *t)
|
|
|
|
{
|
|
|
|
struct mapped_device *md;
|
|
|
|
struct request_queue *queue;
|
|
|
|
unsigned long flags;
|
|
|
|
|
|
|
|
if (!dm_table_request_based(t))
|
|
|
|
return;
|
|
|
|
|
|
|
|
md = dm_table_get_md(t);
|
|
|
|
queue = dm_get_md_queue(md);
|
|
|
|
if (queue) {
|
|
|
|
spin_lock_irqsave(queue->queue_lock, flags);
|
|
|
|
blk_run_queue_async(queue);
|
|
|
|
spin_unlock_irqrestore(queue->queue_lock, flags);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(dm_table_run_md_queue_async);
|
|
|
|
|
2010-08-12 10:14:08 +07:00
|
|
|
static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
|
|
|
|
sector_t start, sector_t len, void *data)
|
|
|
|
{
|
|
|
|
struct request_queue *q = bdev_get_queue(dev->bdev);
|
|
|
|
|
|
|
|
return q && blk_queue_discard(q);
|
|
|
|
}
|
|
|
|
|
|
|
|
bool dm_table_supports_discards(struct dm_table *t)
|
|
|
|
{
|
|
|
|
struct dm_target *ti;
|
|
|
|
unsigned i = 0;
|
|
|
|
|
|
|
|
/*
|
2011-05-29 18:52:55 +07:00
|
|
|
* Unless any target used by the table set discards_supported,
|
|
|
|
* require at least one underlying device to support discards.
|
2010-08-12 10:14:08 +07:00
|
|
|
* t->devices includes internal dm devices such as mirror logs
|
|
|
|
* so we need to use iterate_devices here, which targets
|
2011-08-02 18:32:01 +07:00
|
|
|
* supporting discard selectively must provide.
|
2010-08-12 10:14:08 +07:00
|
|
|
*/
|
|
|
|
while (i < dm_table_get_num_targets(t)) {
|
|
|
|
ti = dm_table_get_target(t, i++);
|
|
|
|
|
2013-03-02 05:45:47 +07:00
|
|
|
if (!ti->num_discard_bios)
|
2011-08-02 18:32:01 +07:00
|
|
|
continue;
|
|
|
|
|
2011-05-29 18:52:55 +07:00
|
|
|
if (ti->discards_supported)
|
|
|
|
return 1;
|
|
|
|
|
2010-08-12 10:14:08 +07:00
|
|
|
if (ti->type->iterate_devices &&
|
|
|
|
ti->type->iterate_devices(ti, device_discard_capable, NULL))
|
|
|
|
return 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|