/*
* Copyright (C) 2001 Sistina Software (UK) Limited.
- * Copyright (C) 2004 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/mutex.h>
+#include <linux/delay.h>
#include <asm/atomic.h>
#define DM_MSG_PREFIX "table"
#define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
+/*
+ * The table has always exactly one reference from either mapped_device->map
+ * or hash_cell->new_map. 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
+ * drop to zero.
+ */
+
struct dm_table {
struct mapped_device *md;
atomic_t holders;
sector_t *highs;
struct dm_target *targets;
+ unsigned barriers_supported:1;
+
/*
* Indicates the rw permissions for the new logical
* device. This should be a combination of FMODE_READ
* and FMODE_WRITE.
*/
- int mode;
+ fmode_t mode;
/* a list of devices used by this table */
struct list_head devices;
lhs->max_segment_size =
min_not_zero(lhs->max_segment_size, rhs->max_segment_size);
+ lhs->max_hw_sectors =
+ min_not_zero(lhs->max_hw_sectors, rhs->max_hw_sectors);
+
lhs->seg_boundary_mask =
min_not_zero(lhs->seg_boundary_mask, rhs->seg_boundary_mask);
+ lhs->bounce_pfn = min_not_zero(lhs->bounce_pfn, rhs->bounce_pfn);
+
lhs->no_cluster |= rhs->no_cluster;
}
/*
* Allocate both the target array and offset array at once.
+ * Append an empty entry to catch sectors beyond the end of
+ * the device.
*/
- n_highs = (sector_t *) dm_vcalloc(num, sizeof(struct dm_target) +
+ n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
sizeof(sector_t));
if (!n_highs)
return -ENOMEM;
return 0;
}
-int dm_table_create(struct dm_table **result, int mode,
+int dm_table_create(struct dm_table **result, fmode_t mode,
unsigned num_targets, struct mapped_device *md)
{
- struct dm_table *t = kmalloc(sizeof(*t), GFP_KERNEL);
+ struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
if (!t)
return -ENOMEM;
- memset(t, 0, sizeof(*t));
INIT_LIST_HEAD(&t->devices);
- atomic_set(&t->holders, 1);
+ atomic_set(&t->holders, 0);
+ t->barriers_supported = 1;
if (!num_targets)
num_targets = KEYS_PER_NODE;
return 0;
}
-int dm_create_error_table(struct dm_table **result, struct mapped_device *md)
-{
- struct dm_table *t;
- sector_t dev_size = 1;
- int r;
-
- /*
- * Find current size of device.
- * Default to 1 sector if inactive.
- */
- t = dm_get_table(md);
- if (t) {
- dev_size = dm_table_get_size(t);
- dm_table_put(t);
- }
-
- r = dm_table_create(&t, FMODE_READ, 1, md);
- if (r)
- return r;
-
- r = dm_table_add_target(t, "error", 0, dev_size, NULL);
- if (r)
- goto out;
-
- r = dm_table_complete(t);
- if (r)
- goto out;
-
- *result = t;
-
-out:
- if (r)
- dm_table_put(t);
-
- return r;
-}
-EXPORT_SYMBOL_GPL(dm_create_error_table);
-
static void free_devices(struct list_head *devices)
{
struct list_head *tmp, *next;
- for (tmp = devices->next; tmp != devices; tmp = next) {
- struct dm_dev *dd = list_entry(tmp, struct dm_dev, list);
- next = tmp->next;
+ list_for_each_safe(tmp, next, devices) {
+ struct dm_dev_internal *dd =
+ list_entry(tmp, struct dm_dev_internal, list);
kfree(dd);
}
}
-static void table_destroy(struct dm_table *t)
+void dm_table_destroy(struct dm_table *t)
{
unsigned int i;
+ while (atomic_read(&t->holders))
+ msleep(1);
+ smp_mb();
+
/* free the indexes (see dm_table_complete) */
if (t->depth >= 2)
vfree(t->index[t->depth - 2]);
if (!t)
return;
- if (atomic_dec_and_test(&t->holders))
- table_destroy(t);
+ smp_mb__before_atomic_dec();
+ atomic_dec(&t->holders);
}
/*
}
/*
- * Convert a device path to a dev_t.
- */
-static int lookup_device(const char *path, dev_t *dev)
-{
- int r;
- struct nameidata nd;
- struct inode *inode;
-
- if ((r = path_lookup(path, LOOKUP_FOLLOW, &nd)))
- return r;
-
- inode = nd.dentry->d_inode;
- if (!inode) {
- r = -ENOENT;
- goto out;
- }
-
- if (!S_ISBLK(inode->i_mode)) {
- r = -ENOTBLK;
- goto out;
- }
-
- *dev = inode->i_rdev;
-
- out:
- path_release(&nd);
- return r;
-}
-
-/*
* See if we've already got a device in the list.
*/
-static struct dm_dev *find_device(struct list_head *l, dev_t dev)
+static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
{
- struct dm_dev *dd;
+ struct dm_dev_internal *dd;
list_for_each_entry (dd, l, list)
- if (dd->bdev->bd_dev == dev)
+ if (dd->dm_dev.bdev->bd_dev == dev)
return dd;
return NULL;
/*
* Open a device so we can use it as a map destination.
*/
-static int open_dev(struct dm_dev *d, dev_t dev, struct mapped_device *md)
+static int open_dev(struct dm_dev_internal *d, dev_t dev,
+ struct mapped_device *md)
{
static char *_claim_ptr = "I belong to device-mapper";
struct block_device *bdev;
int r;
- BUG_ON(d->bdev);
+ BUG_ON(d->dm_dev.bdev);
- bdev = open_by_devnum(dev, d->mode);
+ bdev = open_by_devnum(dev, d->dm_dev.mode);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md));
if (r)
- blkdev_put(bdev);
+ blkdev_put(bdev, d->dm_dev.mode);
else
- d->bdev = bdev;
+ d->dm_dev.bdev = bdev;
return r;
}
/*
* Close a device that we've been using.
*/
-static void close_dev(struct dm_dev *d, struct mapped_device *md)
+static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
{
- if (!d->bdev)
+ if (!d->dm_dev.bdev)
return;
- bd_release_from_disk(d->bdev, dm_disk(md));
- blkdev_put(d->bdev);
- d->bdev = NULL;
+ bd_release_from_disk(d->dm_dev.bdev, dm_disk(md));
+ blkdev_put(d->dm_dev.bdev, d->dm_dev.mode);
+ d->dm_dev.bdev = NULL;
}
/*
* If possible, this checks an area of a destination device is valid.
*/
-static int check_device_area(struct dm_dev *dd, sector_t start, sector_t len)
+static int check_device_area(struct dm_dev_internal *dd, sector_t start,
+ sector_t len)
{
- sector_t dev_size = dd->bdev->bd_inode->i_size >> SECTOR_SHIFT;
+ sector_t dev_size = dd->dm_dev.bdev->bd_inode->i_size >> SECTOR_SHIFT;
if (!dev_size)
return 1;
* careful to leave things as they were if we fail to reopen the
* device.
*/
-static int upgrade_mode(struct dm_dev *dd, int new_mode, struct mapped_device *md)
+static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
+ struct mapped_device *md)
{
int r;
- struct dm_dev dd_copy;
- dev_t dev = dd->bdev->bd_dev;
+ struct dm_dev_internal dd_copy;
+ dev_t dev = dd->dm_dev.bdev->bd_dev;
dd_copy = *dd;
- dd->mode |= new_mode;
- dd->bdev = NULL;
+ dd->dm_dev.mode |= new_mode;
+ dd->dm_dev.bdev = NULL;
r = open_dev(dd, dev, md);
if (!r)
close_dev(&dd_copy, md);
*/
static int __table_get_device(struct dm_table *t, struct dm_target *ti,
const char *path, sector_t start, sector_t len,
- int mode, struct dm_dev **result)
+ fmode_t mode, struct dm_dev **result)
{
int r;
- dev_t dev;
- struct dm_dev *dd;
+ dev_t uninitialized_var(dev);
+ struct dm_dev_internal *dd;
unsigned int major, minor;
BUG_ON(!t);
return -EOVERFLOW;
} else {
/* convert the path to a device */
- if ((r = lookup_device(path, &dev)))
- return r;
+ struct block_device *bdev = lookup_bdev(path);
+
+ if (IS_ERR(bdev))
+ return PTR_ERR(bdev);
+ dev = bdev->bd_dev;
+ bdput(bdev);
}
dd = find_device(&t->devices, dev);
if (!dd)
return -ENOMEM;
- dd->mode = mode;
- dd->bdev = NULL;
+ dd->dm_dev.mode = mode;
+ dd->dm_dev.bdev = NULL;
if ((r = open_dev(dd, dev, t->md))) {
kfree(dd);
return r;
}
- format_dev_t(dd->name, dev);
+ format_dev_t(dd->dm_dev.name, dev);
atomic_set(&dd->count, 0);
list_add(&dd->list, &t->devices);
- } else if (dd->mode != (mode | dd->mode)) {
+ } else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) {
r = upgrade_mode(dd, mode, t->md);
if (r)
return r;
if (!check_device_area(dd, start, len)) {
DMWARN("device %s too small for target", path);
- dm_put_device(ti, dd);
+ dm_put_device(ti, &dd->dm_dev);
return -EINVAL;
}
- *result = dd;
+ *result = &dd->dm_dev;
return 0;
}
{
struct request_queue *q = bdev_get_queue(bdev);
struct io_restrictions *rs = &ti->limits;
+ 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));
+ return;
+ }
/*
* Combine the device limits low.
rs->max_sectors =
min_not_zero(rs->max_sectors, q->max_sectors);
- /* FIXME: Device-Mapper on top of RAID-0 breaks because DM
- * currently doesn't honor MD's merge_bvec_fn routine.
- * In this case, we'll force DM to use PAGE_SIZE or
- * smaller I/O, just to be safe. A better fix is in the
- * works, but add this for the time being so it will at
- * least operate correctly.
+ /*
+ * Check if merge fn is supported.
+ * If not we'll force DM to use PAGE_SIZE or
+ * smaller I/O, just to be safe.
*/
- if (q->merge_bvec_fn)
+
+ if (q->merge_bvec_fn && !ti->type->merge)
rs->max_sectors =
min_not_zero(rs->max_sectors,
(unsigned int) (PAGE_SIZE >> 9));
rs->max_segment_size =
min_not_zero(rs->max_segment_size, q->max_segment_size);
+ rs->max_hw_sectors =
+ min_not_zero(rs->max_hw_sectors, q->max_hw_sectors);
+
rs->seg_boundary_mask =
min_not_zero(rs->seg_boundary_mask,
q->seg_boundary_mask);
+ rs->bounce_pfn = min_not_zero(rs->bounce_pfn, q->bounce_pfn);
+
rs->no_cluster |= !test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
}
EXPORT_SYMBOL_GPL(dm_set_device_limits);
int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
- sector_t len, int mode, struct dm_dev **result)
+ sector_t len, fmode_t mode, struct dm_dev **result)
{
int r = __table_get_device(ti->table, ti, path,
start, len, mode, result);
/*
* Decrement a devices use count and remove it if necessary.
*/
-void dm_put_device(struct dm_target *ti, struct dm_dev *dd)
+void dm_put_device(struct dm_target *ti, struct dm_dev *d)
{
+ struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal,
+ dm_dev);
+
if (atomic_dec_and_test(&dd->count)) {
close_dev(dd, ti->table->md);
list_del(&dd->list);
{
if (!rs->max_sectors)
rs->max_sectors = SAFE_MAX_SECTORS;
+ if (!rs->max_hw_sectors)
+ rs->max_hw_sectors = SAFE_MAX_SECTORS;
if (!rs->max_phys_segments)
rs->max_phys_segments = MAX_PHYS_SEGMENTS;
if (!rs->max_hw_segments)
if (!rs->max_segment_size)
rs->max_segment_size = MAX_SEGMENT_SIZE;
if (!rs->seg_boundary_mask)
- rs->seg_boundary_mask = -1;
+ rs->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
+ if (!rs->bounce_pfn)
+ rs->bounce_pfn = -1;
}
int dm_table_add_target(struct dm_table *t, const char *type,
/* FIXME: the plan is to combine high here and then have
* the merge fn apply the target level restrictions. */
combine_restrictions_low(&t->limits, &tgt->limits);
+
+ if (!(tgt->type->features & DM_TARGET_SUPPORTS_BARRIERS))
+ t->barriers_supported = 0;
+
return 0;
bad:
return -ENOMEM;
/* set up internal nodes, bottom-up */
- for (i = t->depth - 2, total = 0; i >= 0; i--) {
+ for (i = t->depth - 2; i >= 0; i--) {
t->index[i] = indexes;
indexes += (KEYS_PER_NODE * t->counts[i]);
setup_btree_index(i, t);
check_for_valid_limits(&t->limits);
+ /*
+ * We only support barriers if there is exactly one underlying device.
+ */
+ if (!list_is_singular(&t->devices))
+ t->barriers_supported = 0;
+
/* 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);
/*
* Search the btree for the correct target.
+ *
+ * Caller should check returned pointer with dm_target_is_valid()
+ * to trap I/O beyond end of device.
*/
struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
{
q->max_hw_segments = t->limits.max_hw_segments;
q->hardsect_size = t->limits.hardsect_size;
q->max_segment_size = t->limits.max_segment_size;
+ q->max_hw_sectors = t->limits.max_hw_sectors;
q->seg_boundary_mask = t->limits.seg_boundary_mask;
+ q->bounce_pfn = t->limits.bounce_pfn;
+
if (t->limits.no_cluster)
- q->queue_flags &= ~(1 << QUEUE_FLAG_CLUSTER);
+ queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q);
else
- q->queue_flags |= (1 << QUEUE_FLAG_CLUSTER);
+ queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, q);
}
return &t->devices;
}
-int dm_table_get_mode(struct dm_table *t)
+fmode_t dm_table_get_mode(struct dm_table *t)
{
return t->mode;
}
if (!t)
return;
- return suspend_targets(t, 0);
+ suspend_targets(t, 0);
}
void dm_table_postsuspend_targets(struct dm_table *t)
if (!t)
return;
- return suspend_targets(t, 1);
+ suspend_targets(t, 1);
}
int dm_table_resume_targets(struct dm_table *t)
int dm_table_any_congested(struct dm_table *t, int bdi_bits)
{
- struct list_head *d, *devices;
+ struct dm_dev_internal *dd;
+ struct list_head *devices = dm_table_get_devices(t);
int r = 0;
- devices = dm_table_get_devices(t);
- for (d = devices->next; d != devices; d = d->next) {
- struct dm_dev *dd = list_entry(d, struct dm_dev, list);
- struct request_queue *q = bdev_get_queue(dd->bdev);
- r |= bdi_congested(&q->backing_dev_info, bdi_bits);
+ list_for_each_entry(dd, devices, list) {
+ struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
+ 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));
}
return r;
void dm_table_unplug_all(struct dm_table *t)
{
- struct list_head *d, *devices = dm_table_get_devices(t);
-
- for (d = devices->next; d != devices; d = d->next) {
- struct dm_dev *dd = list_entry(d, struct dm_dev, list);
- struct request_queue *q = bdev_get_queue(dd->bdev);
+ struct dm_dev_internal *dd;
+ struct list_head *devices = dm_table_get_devices(t);
- if (q->unplug_fn)
- q->unplug_fn(q);
- }
-}
+ list_for_each_entry(dd, devices, list) {
+ struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
+ char b[BDEVNAME_SIZE];
-int dm_table_flush_all(struct dm_table *t)
-{
- struct list_head *d, *devices = dm_table_get_devices(t);
- int ret = 0;
- unsigned i;
-
- for (i = 0; i < t->num_targets; i++)
- if (t->targets[i].type->flush)
- t->targets[i].type->flush(&t->targets[i]);
-
- for (d = devices->next; d != devices; d = d->next) {
- struct dm_dev *dd = list_entry(d, struct dm_dev, list);
- struct request_queue *q = bdev_get_queue(dd->bdev);
- int err;
-
- if (!q->issue_flush_fn)
- err = -EOPNOTSUPP;
+ if (likely(q))
+ blk_unplug(q);
else
- err = q->issue_flush_fn(q, dd->bdev->bd_disk, NULL);
-
- if (!ret)
- ret = err;
+ DMWARN_LIMIT("%s: Cannot unplug nonexistent device %s",
+ dm_device_name(t->md),
+ bdevname(dd->dm_dev.bdev, b));
}
-
- return ret;
}
struct mapped_device *dm_table_get_md(struct dm_table *t)
return t->md;
}
+int dm_table_barrier_ok(struct dm_table *t)
+{
+ return t->barriers_supported;
+}
+EXPORT_SYMBOL(dm_table_barrier_ok);
+
EXPORT_SYMBOL(dm_vcalloc);
EXPORT_SYMBOL(dm_get_device);
EXPORT_SYMBOL(dm_put_device);
EXPORT_SYMBOL(dm_table_put);
EXPORT_SYMBOL(dm_table_get);
EXPORT_SYMBOL(dm_table_unplug_all);
-EXPORT_SYMBOL(dm_table_flush_all);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff