bl->tail = bio;
}
+static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
+{
+ bio->bi_next = bl->head;
+
+ bl->head = bio;
+
+ if (!bl->tail)
+ bl->tail = bio;
+}
+
static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
{
if (!bl2->head)
* functions in this file help the target record and restore the
* original bio state.
*/
+
+struct dm_bio_vec_details {
+#if PAGE_SIZE < 65536
+ __u16 bv_len;
+ __u16 bv_offset;
+#else
+ unsigned bv_len;
+ unsigned bv_offset;
+#endif
+};
+
struct dm_bio_details {
sector_t bi_sector;
struct block_device *bi_bdev;
unsigned int bi_size;
unsigned short bi_idx;
unsigned long bi_flags;
+ struct dm_bio_vec_details bi_io_vec[BIO_MAX_PAGES];
};
static inline void dm_bio_record(struct dm_bio_details *bd, struct bio *bio)
{
+ unsigned i;
+
bd->bi_sector = bio->bi_sector;
bd->bi_bdev = bio->bi_bdev;
bd->bi_size = bio->bi_size;
bd->bi_idx = bio->bi_idx;
bd->bi_flags = bio->bi_flags;
+
+ for (i = 0; i < bio->bi_vcnt; i++) {
+ bd->bi_io_vec[i].bv_len = bio->bi_io_vec[i].bv_len;
+ bd->bi_io_vec[i].bv_offset = bio->bi_io_vec[i].bv_offset;
+ }
}
static inline void dm_bio_restore(struct dm_bio_details *bd, struct bio *bio)
{
+ unsigned i;
+
bio->bi_sector = bd->bi_sector;
bio->bi_bdev = bd->bi_bdev;
bio->bi_size = bd->bi_size;
bio->bi_idx = bd->bi_idx;
bio->bi_flags = bd->bi_flags;
+
+ for (i = 0; i < bio->bi_vcnt; i++) {
+ bio->bi_io_vec[i].bv_len = bd->bi_io_vec[i].bv_len;
+ bio->bi_io_vec[i].bv_offset = bd->bi_io_vec[i].bv_offset;
+ }
}
#endif
crypto_free_ablkcipher(tfm);
bad_cipher:
/* Must zero key material before freeing */
- memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
- kfree(cc);
+ kzfree(cc);
return -EINVAL;
}
dm_put_device(ti, cc->dev);
/* Must zero key material before freeing */
- memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
- kfree(cc);
+ kzfree(cc);
}
static int crypt_map(struct dm_target *ti, struct bio *bio,
#include "dm-exception-store.h"
+#include <linux/ctype.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/vmalloc.h>
#define DM_MSG_PREFIX "snapshot exception stores"
+static LIST_HEAD(_exception_store_types);
+static DEFINE_SPINLOCK(_lock);
+
+static struct dm_exception_store_type *__find_exception_store_type(const char *name)
+{
+ struct dm_exception_store_type *type;
+
+ list_for_each_entry(type, &_exception_store_types, list)
+ if (!strcmp(name, type->name))
+ return type;
+
+ return NULL;
+}
+
+static struct dm_exception_store_type *_get_exception_store_type(const char *name)
+{
+ struct dm_exception_store_type *type;
+
+ spin_lock(&_lock);
+
+ type = __find_exception_store_type(name);
+
+ if (type && !try_module_get(type->module))
+ type = NULL;
+
+ spin_unlock(&_lock);
+
+ return type;
+}
+
+/*
+ * get_type
+ * @type_name
+ *
+ * Attempt to retrieve the dm_exception_store_type by name. If not already
+ * available, attempt to load the appropriate module.
+ *
+ * Exstore modules are named "dm-exstore-" followed by the 'type_name'.
+ * Modules may contain multiple types.
+ * This function will first try the module "dm-exstore-<type_name>",
+ * then truncate 'type_name' on the last '-' and try again.
+ *
+ * For example, if type_name was "clustered-shared", it would search
+ * 'dm-exstore-clustered-shared' then 'dm-exstore-clustered'.
+ *
+ * 'dm-exception-store-<type_name>' is too long of a name in my
+ * opinion, which is why I've chosen to have the files
+ * containing exception store implementations be 'dm-exstore-<type_name>'.
+ * If you want your module to be autoloaded, you will follow this
+ * naming convention.
+ *
+ * Returns: dm_exception_store_type* on success, NULL on failure
+ */
+static struct dm_exception_store_type *get_type(const char *type_name)
+{
+ char *p, *type_name_dup;
+ struct dm_exception_store_type *type;
+
+ type = _get_exception_store_type(type_name);
+ if (type)
+ return type;
+
+ type_name_dup = kstrdup(type_name, GFP_KERNEL);
+ if (!type_name_dup) {
+ DMERR("No memory left to attempt load for \"%s\"", type_name);
+ return NULL;
+ }
+
+ while (request_module("dm-exstore-%s", type_name_dup) ||
+ !(type = _get_exception_store_type(type_name))) {
+ p = strrchr(type_name_dup, '-');
+ if (!p)
+ break;
+ p[0] = '\0';
+ }
+
+ if (!type)
+ DMWARN("Module for exstore type \"%s\" not found.", type_name);
+
+ kfree(type_name_dup);
+
+ return type;
+}
+
+static void put_type(struct dm_exception_store_type *type)
+{
+ spin_lock(&_lock);
+ module_put(type->module);
+ spin_unlock(&_lock);
+}
+
+int dm_exception_store_type_register(struct dm_exception_store_type *type)
+{
+ int r = 0;
+
+ spin_lock(&_lock);
+ if (!__find_exception_store_type(type->name))
+ list_add(&type->list, &_exception_store_types);
+ else
+ r = -EEXIST;
+ spin_unlock(&_lock);
+
+ return r;
+}
+EXPORT_SYMBOL(dm_exception_store_type_register);
+
+int dm_exception_store_type_unregister(struct dm_exception_store_type *type)
+{
+ spin_lock(&_lock);
+
+ if (!__find_exception_store_type(type->name)) {
+ spin_unlock(&_lock);
+ return -EINVAL;
+ }
+
+ list_del(&type->list);
+
+ spin_unlock(&_lock);
+
+ return 0;
+}
+EXPORT_SYMBOL(dm_exception_store_type_unregister);
+
+/*
+ * Round a number up to the nearest 'size' boundary. size must
+ * be a power of 2.
+ */
+static ulong round_up(ulong n, ulong size)
+{
+ size--;
+ return (n + size) & ~size;
+}
+
+static int set_chunk_size(struct dm_exception_store *store,
+ const char *chunk_size_arg, char **error)
+{
+ unsigned long chunk_size_ulong;
+ char *value;
+
+ chunk_size_ulong = simple_strtoul(chunk_size_arg, &value, 10);
+ if (*chunk_size_arg == '\0' || *value != '\0') {
+ *error = "Invalid chunk size";
+ return -EINVAL;
+ }
+
+ if (!chunk_size_ulong) {
+ store->chunk_size = store->chunk_mask = store->chunk_shift = 0;
+ return 0;
+ }
+
+ /*
+ * Chunk size must be multiple of page size. Silently
+ * round up if it's not.
+ */
+ chunk_size_ulong = round_up(chunk_size_ulong, PAGE_SIZE >> 9);
+
+ /* Check chunk_size is a power of 2 */
+ if (!is_power_of_2(chunk_size_ulong)) {
+ *error = "Chunk size is not a power of 2";
+ return -EINVAL;
+ }
+
+ /* Validate the chunk size against the device block size */
+ if (chunk_size_ulong % (bdev_hardsect_size(store->cow->bdev) >> 9)) {
+ *error = "Chunk size is not a multiple of device blocksize";
+ return -EINVAL;
+ }
+
+ store->chunk_size = chunk_size_ulong;
+ store->chunk_mask = chunk_size_ulong - 1;
+ store->chunk_shift = ffs(chunk_size_ulong) - 1;
+
+ return 0;
+}
+
+int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
+ unsigned *args_used,
+ struct dm_exception_store **store)
+{
+ int r = 0;
+ struct dm_exception_store_type *type;
+ struct dm_exception_store *tmp_store;
+ char persistent;
+
+ if (argc < 3) {
+ ti->error = "Insufficient exception store arguments";
+ return -EINVAL;
+ }
+
+ tmp_store = kmalloc(sizeof(*tmp_store), GFP_KERNEL);
+ if (!tmp_store) {
+ ti->error = "Exception store allocation failed";
+ return -ENOMEM;
+ }
+
+ persistent = toupper(*argv[1]);
+ if (persistent != 'P' && persistent != 'N') {
+ ti->error = "Persistent flag is not P or N";
+ return -EINVAL;
+ }
+
+ type = get_type(argv[1]);
+ if (!type) {
+ ti->error = "Exception store type not recognised";
+ r = -EINVAL;
+ goto bad_type;
+ }
+
+ tmp_store->type = type;
+ tmp_store->ti = ti;
+
+ r = dm_get_device(ti, argv[0], 0, 0,
+ FMODE_READ | FMODE_WRITE, &tmp_store->cow);
+ if (r) {
+ ti->error = "Cannot get COW device";
+ goto bad_cow;
+ }
+
+ r = set_chunk_size(tmp_store, argv[2], &ti->error);
+ if (r)
+ goto bad_cow;
+
+ r = type->ctr(tmp_store, 0, NULL);
+ if (r) {
+ ti->error = "Exception store type constructor failed";
+ goto bad_ctr;
+ }
+
+ *args_used = 3;
+ *store = tmp_store;
+ return 0;
+
+bad_ctr:
+ dm_put_device(ti, tmp_store->cow);
+bad_cow:
+ put_type(type);
+bad_type:
+ kfree(tmp_store);
+ return r;
+}
+EXPORT_SYMBOL(dm_exception_store_create);
+
+void dm_exception_store_destroy(struct dm_exception_store *store)
+{
+ store->type->dtr(store);
+ dm_put_device(store->ti, store->cow);
+ put_type(store->type);
+ kfree(store);
+}
+EXPORT_SYMBOL(dm_exception_store_destroy);
+
int dm_exception_store_init(void)
{
int r;
* Abstraction to handle the meta/layout of exception stores (the
* COW device).
*/
-struct dm_exception_store {
+struct dm_exception_store;
+struct dm_exception_store_type {
+ const char *name;
+ struct module *module;
+
+ int (*ctr) (struct dm_exception_store *store,
+ unsigned argc, char **argv);
+
/*
* Destroys this object when you've finished with it.
*/
- void (*destroy) (struct dm_exception_store *store);
+ void (*dtr) (struct dm_exception_store *store);
/*
* The target shouldn't read the COW device until this is
*/
void (*drop_snapshot) (struct dm_exception_store *store);
- int (*status) (struct dm_exception_store *store, status_type_t status,
- char *result, unsigned int maxlen);
+ unsigned (*status) (struct dm_exception_store *store,
+ status_type_t status, char *result,
+ unsigned maxlen);
/*
* Return how full the snapshot is.
sector_t *numerator,
sector_t *denominator);
- struct dm_snapshot *snap;
+ /* For internal device-mapper use only. */
+ struct list_head list;
+};
+
+struct dm_exception_store {
+ struct dm_exception_store_type *type;
+ struct dm_target *ti;
+
+ struct dm_dev *cow;
+
+ /* Size of data blocks saved - must be a power of 2 */
+ chunk_t chunk_size;
+ chunk_t chunk_mask;
+ chunk_t chunk_shift;
+
void *context;
};
# endif
+/*
+ * Return the number of sectors in the device.
+ */
+static inline sector_t get_dev_size(struct block_device *bdev)
+{
+ return bdev->bd_inode->i_size >> SECTOR_SHIFT;
+}
+
+static inline chunk_t sector_to_chunk(struct dm_exception_store *store,
+ sector_t sector)
+{
+ return (sector & ~store->chunk_mask) >> store->chunk_shift;
+}
+
+int dm_exception_store_type_register(struct dm_exception_store_type *type);
+int dm_exception_store_type_unregister(struct dm_exception_store_type *type);
+
+int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
+ unsigned *args_used,
+ struct dm_exception_store **store);
+void dm_exception_store_destroy(struct dm_exception_store *store);
+
int dm_exception_store_init(void);
void dm_exception_store_exit(void);
int dm_transient_snapshot_init(void);
void dm_transient_snapshot_exit(void);
-int dm_create_persistent(struct dm_exception_store *store);
-
-int dm_create_transient(struct dm_exception_store *store);
-
#endif /* _LINUX_DM_EXCEPTION_STORE */
while (1) {
set_current_state(TASK_UNINTERRUPTIBLE);
- if (!atomic_read(&io.count) || signal_pending(current))
+ if (!atomic_read(&io.count))
break;
io_schedule();
}
set_current_state(TASK_RUNNING);
- if (atomic_read(&io.count))
- return -EINTR;
-
if (error_bits)
*error_bits = io.error_bits;
#define DM_MSG_PREFIX "dirty region log"
-struct dm_dirty_log_internal {
- struct dm_dirty_log_type *type;
-
- struct list_head list;
- long use;
-};
-
static LIST_HEAD(_log_types);
static DEFINE_SPINLOCK(_lock);
-static struct dm_dirty_log_internal *__find_dirty_log_type(const char *name)
+static struct dm_dirty_log_type *__find_dirty_log_type(const char *name)
{
- struct dm_dirty_log_internal *log_type;
+ struct dm_dirty_log_type *log_type;
list_for_each_entry(log_type, &_log_types, list)
- if (!strcmp(name, log_type->type->name))
+ if (!strcmp(name, log_type->name))
return log_type;
return NULL;
}
-static struct dm_dirty_log_internal *_get_dirty_log_type(const char *name)
+static struct dm_dirty_log_type *_get_dirty_log_type(const char *name)
{
- struct dm_dirty_log_internal *log_type;
+ struct dm_dirty_log_type *log_type;
spin_lock(&_lock);
log_type = __find_dirty_log_type(name);
- if (log_type) {
- if (!log_type->use && !try_module_get(log_type->type->module))
- log_type = NULL;
- else
- log_type->use++;
- }
+ if (log_type && !try_module_get(log_type->module))
+ log_type = NULL;
spin_unlock(&_lock);
static struct dm_dirty_log_type *get_type(const char *type_name)
{
char *p, *type_name_dup;
- struct dm_dirty_log_internal *log_type;
+ struct dm_dirty_log_type *log_type;
if (!type_name)
return NULL;
log_type = _get_dirty_log_type(type_name);
if (log_type)
- return log_type->type;
+ return log_type;
type_name_dup = kstrdup(type_name, GFP_KERNEL);
if (!type_name_dup) {
kfree(type_name_dup);
- return log_type ? log_type->type : NULL;
+ return log_type;
}
static void put_type(struct dm_dirty_log_type *type)
{
- struct dm_dirty_log_internal *log_type;
-
if (!type)
return;
spin_lock(&_lock);
- log_type = __find_dirty_log_type(type->name);
- if (!log_type)
+ if (!__find_dirty_log_type(type->name))
goto out;
- if (!--log_type->use)
- module_put(type->module);
-
- BUG_ON(log_type->use < 0);
+ module_put(type->module);
out:
spin_unlock(&_lock);
}
-static struct dm_dirty_log_internal *_alloc_dirty_log_type(struct dm_dirty_log_type *type)
-{
- struct dm_dirty_log_internal *log_type = kzalloc(sizeof(*log_type),
- GFP_KERNEL);
-
- if (log_type)
- log_type->type = type;
-
- return log_type;
-}
-
int dm_dirty_log_type_register(struct dm_dirty_log_type *type)
{
- struct dm_dirty_log_internal *log_type = _alloc_dirty_log_type(type);
int r = 0;
- if (!log_type)
- return -ENOMEM;
-
spin_lock(&_lock);
if (!__find_dirty_log_type(type->name))
- list_add(&log_type->list, &_log_types);
- else {
- kfree(log_type);
+ list_add(&type->list, &_log_types);
+ else
r = -EEXIST;
- }
spin_unlock(&_lock);
return r;
int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
{
- struct dm_dirty_log_internal *log_type;
-
spin_lock(&_lock);
- log_type = __find_dirty_log_type(type->name);
- if (!log_type) {
+ if (!__find_dirty_log_type(type->name)) {
spin_unlock(&_lock);
return -EINVAL;
}
- if (log_type->use) {
- spin_unlock(&_lock);
- return -ETXTBSY;
- }
-
- list_del(&log_type->list);
+ list_del(&type->list);
spin_unlock(&_lock);
- kfree(log_type);
return 0;
}
struct ps_internal {
struct path_selector_type pst;
-
struct list_head list;
- long use;
};
#define pst_to_psi(__pst) container_of((__pst), struct ps_internal, pst)
down_read(&_ps_lock);
psi = __find_path_selector_type(name);
- if (psi) {
- if ((psi->use == 0) && !try_module_get(psi->pst.module))
- psi = NULL;
- else
- psi->use++;
- }
+ if (psi && !try_module_get(psi->pst.module))
+ psi = NULL;
up_read(&_ps_lock);
return psi;
if (!psi)
goto out;
- if (--psi->use == 0)
- module_put(psi->pst.module);
-
- BUG_ON(psi->use < 0);
-
+ module_put(psi->pst.module);
out:
up_read(&_ps_lock);
}
return -EINVAL;
}
- if (psi->use) {
- up_write(&_ps_lock);
- return -ETXTBSY;
- }
-
list_del(&psi->list);
up_write(&_ps_lock);
struct dm_bio_details details;
};
+static struct kmem_cache *_dm_raid1_read_record_cache;
+
/*
* Every mirror should look like this one.
*/
int state;
struct bio *bio;
struct bio_list sync, nosync, recover, *this_list = NULL;
+ struct bio_list requeue;
+ struct dm_dirty_log *log = dm_rh_dirty_log(ms->rh);
+ region_t region;
if (!writes->head)
return;
bio_list_init(&sync);
bio_list_init(&nosync);
bio_list_init(&recover);
+ bio_list_init(&requeue);
while ((bio = bio_list_pop(writes))) {
- state = dm_rh_get_state(ms->rh,
- dm_rh_bio_to_region(ms->rh, bio), 1);
+ region = dm_rh_bio_to_region(ms->rh, bio);
+
+ if (log->type->is_remote_recovering &&
+ log->type->is_remote_recovering(log, region)) {
+ bio_list_add(&requeue, bio);
+ continue;
+ }
+
+ state = dm_rh_get_state(ms->rh, region, 1);
switch (state) {
case DM_RH_CLEAN:
case DM_RH_DIRTY:
bio_list_add(this_list, bio);
}
+ /*
+ * Add bios that are delayed due to remote recovery
+ * back on to the write queue
+ */
+ if (unlikely(requeue.head)) {
+ spin_lock_irq(&ms->lock);
+ bio_list_merge(&ms->writes, &requeue);
+ spin_unlock_irq(&ms->lock);
+ }
+
/*
* Increment the pending counts for any regions that will
* be written to (writes to recover regions are going to
atomic_set(&ms->suspend, 0);
atomic_set(&ms->default_mirror, DEFAULT_MIRROR);
- len = sizeof(struct dm_raid1_read_record);
- ms->read_record_pool = mempool_create_kmalloc_pool(MIN_READ_RECORDS,
- len);
+ ms->read_record_pool = mempool_create_slab_pool(MIN_READ_RECORDS,
+ _dm_raid1_read_record_cache);
+
if (!ms->read_record_pool) {
ti->error = "Error creating mirror read_record_pool";
kfree(ms);
{
int r;
+ _dm_raid1_read_record_cache = KMEM_CACHE(dm_raid1_read_record, 0);
+ if (!_dm_raid1_read_record_cache) {
+ DMERR("Can't allocate dm_raid1_read_record cache");
+ r = -ENOMEM;
+ goto bad_cache;
+ }
+
r = dm_register_target(&mirror_target);
- if (r < 0)
+ if (r < 0) {
DMERR("Failed to register mirror target");
+ goto bad_target;
+ }
+
+ return 0;
+bad_target:
+ kmem_cache_destroy(_dm_raid1_read_record_cache);
+bad_cache:
return r;
}
static void __exit dm_mirror_exit(void)
{
dm_unregister_target(&mirror_target);
+ kmem_cache_destroy(_dm_raid1_read_record_cache);
}
/* Module hooks */
*/
#include "dm-exception-store.h"
-#include "dm-snap.h"
#include <linux/mm.h>
#include <linux/pagemap.h>
* The top level structure for a persistent exception store.
*/
struct pstore {
- struct dm_snapshot *snap; /* up pointer to my snapshot */
+ struct dm_exception_store *store;
int version;
int valid;
uint32_t exceptions_per_area;
int r = -ENOMEM;
size_t len;
- len = ps->snap->chunk_size << SECTOR_SHIFT;
+ len = ps->store->chunk_size << SECTOR_SHIFT;
/*
* Allocate the chunk_size block of memory that will hold
static void free_area(struct pstore *ps)
{
- vfree(ps->area);
+ if (ps->area)
+ vfree(ps->area);
ps->area = NULL;
- vfree(ps->zero_area);
+
+ if (ps->zero_area)
+ vfree(ps->zero_area);
ps->zero_area = NULL;
}
static int chunk_io(struct pstore *ps, chunk_t chunk, int rw, int metadata)
{
struct dm_io_region where = {
- .bdev = ps->snap->cow->bdev,
- .sector = ps->snap->chunk_size * chunk,
- .count = ps->snap->chunk_size,
+ .bdev = ps->store->cow->bdev,
+ .sector = ps->store->chunk_size * chunk,
+ .count = ps->store->chunk_size,
};
struct dm_io_request io_req = {
.bi_rw = rw,
static void zero_memory_area(struct pstore *ps)
{
- memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT);
+ memset(ps->area, 0, ps->store->chunk_size << SECTOR_SHIFT);
}
static int zero_disk_area(struct pstore *ps, chunk_t area)
{
struct dm_io_region where = {
- .bdev = ps->snap->cow->bdev,
- .sector = ps->snap->chunk_size * area_location(ps, area),
- .count = ps->snap->chunk_size,
+ .bdev = ps->store->cow->bdev,
+ .sector = ps->store->chunk_size * area_location(ps, area),
+ .count = ps->store->chunk_size,
};
struct dm_io_request io_req = {
.bi_rw = WRITE,
/*
* Use default chunk size (or hardsect_size, if larger) if none supplied
*/
- if (!ps->snap->chunk_size) {
- ps->snap->chunk_size = max(DM_CHUNK_SIZE_DEFAULT_SECTORS,
- bdev_hardsect_size(ps->snap->cow->bdev) >> 9);
- ps->snap->chunk_mask = ps->snap->chunk_size - 1;
- ps->snap->chunk_shift = ffs(ps->snap->chunk_size) - 1;
+ if (!ps->store->chunk_size) {
+ ps->store->chunk_size = max(DM_CHUNK_SIZE_DEFAULT_SECTORS,
+ bdev_hardsect_size(ps->store->cow->bdev) >> 9);
+ ps->store->chunk_mask = ps->store->chunk_size - 1;
+ ps->store->chunk_shift = ffs(ps->store->chunk_size) - 1;
chunk_size_supplied = 0;
}
- ps->io_client = dm_io_client_create(sectors_to_pages(ps->snap->
+ ps->io_client = dm_io_client_create(sectors_to_pages(ps->store->
chunk_size));
if (IS_ERR(ps->io_client))
return PTR_ERR(ps->io_client);
ps->version = le32_to_cpu(dh->version);
chunk_size = le32_to_cpu(dh->chunk_size);
- if (!chunk_size_supplied || ps->snap->chunk_size == chunk_size)
+ if (!chunk_size_supplied || ps->store->chunk_size == chunk_size)
return 0;
DMWARN("chunk size %llu in device metadata overrides "
"table chunk size of %llu.",
(unsigned long long)chunk_size,
- (unsigned long long)ps->snap->chunk_size);
+ (unsigned long long)ps->store->chunk_size);
/* We had a bogus chunk_size. Fix stuff up. */
free_area(ps);
- ps->snap->chunk_size = chunk_size;
- ps->snap->chunk_mask = chunk_size - 1;
- ps->snap->chunk_shift = ffs(chunk_size) - 1;
+ ps->store->chunk_size = chunk_size;
+ ps->store->chunk_mask = chunk_size - 1;
+ ps->store->chunk_shift = ffs(chunk_size) - 1;
- r = dm_io_client_resize(sectors_to_pages(ps->snap->chunk_size),
+ r = dm_io_client_resize(sectors_to_pages(ps->store->chunk_size),
ps->io_client);
if (r)
return r;
{
struct disk_header *dh;
- memset(ps->area, 0, ps->snap->chunk_size << SECTOR_SHIFT);
+ memset(ps->area, 0, ps->store->chunk_size << SECTOR_SHIFT);
dh = (struct disk_header *) ps->area;
dh->magic = cpu_to_le32(SNAP_MAGIC);
dh->valid = cpu_to_le32(ps->valid);
dh->version = cpu_to_le32(ps->version);
- dh->chunk_size = cpu_to_le32(ps->snap->chunk_size);
+ dh->chunk_size = cpu_to_le32(ps->store->chunk_size);
return chunk_io(ps, 0, WRITE, 1);
}
static void persistent_fraction_full(struct dm_exception_store *store,
sector_t *numerator, sector_t *denominator)
{
- *numerator = get_info(store)->next_free * store->snap->chunk_size;
- *denominator = get_dev_size(store->snap->cow->bdev);
+ *numerator = get_info(store)->next_free * store->chunk_size;
+ *denominator = get_dev_size(store->cow->bdev);
}
-static void persistent_destroy(struct dm_exception_store *store)
+static void persistent_dtr(struct dm_exception_store *store)
{
struct pstore *ps = get_info(store);
destroy_workqueue(ps->metadata_wq);
- dm_io_client_destroy(ps->io_client);
- vfree(ps->callbacks);
+
+ /* Created in read_header */
+ if (ps->io_client)
+ dm_io_client_destroy(ps->io_client);
free_area(ps);
+
+ /* Allocated in persistent_read_metadata */
+ if (ps->callbacks)
+ vfree(ps->callbacks);
+
kfree(ps);
}
/*
* Now we know correct chunk_size, complete the initialisation.
*/
- ps->exceptions_per_area = (ps->snap->chunk_size << SECTOR_SHIFT) /
+ ps->exceptions_per_area = (ps->store->chunk_size << SECTOR_SHIFT) /
sizeof(struct disk_exception);
ps->callbacks = dm_vcalloc(ps->exceptions_per_area,
sizeof(*ps->callbacks));
struct pstore *ps = get_info(store);
uint32_t stride;
chunk_t next_free;
- sector_t size = get_dev_size(store->snap->cow->bdev);
+ sector_t size = get_dev_size(store->cow->bdev);
/* Is there enough room ? */
- if (size < ((ps->next_free + 1) * store->snap->chunk_size))
+ if (size < ((ps->next_free + 1) * store->chunk_size))
return -ENOSPC;
e->new_chunk = ps->next_free;
DMWARN("write header failed");
}
-int dm_create_persistent(struct dm_exception_store *store)
+static int persistent_ctr(struct dm_exception_store *store,
+ unsigned argc, char **argv)
{
struct pstore *ps;
/* allocate the pstore */
- ps = kmalloc(sizeof(*ps), GFP_KERNEL);
+ ps = kzalloc(sizeof(*ps), GFP_KERNEL);
if (!ps)
return -ENOMEM;
- ps->snap = store->snap;
+ ps->store = store;
ps->valid = 1;
ps->version = SNAPSHOT_DISK_VERSION;
ps->area = NULL;
return -ENOMEM;
}
- store->destroy = persistent_destroy;
- store->read_metadata = persistent_read_metadata;
- store->prepare_exception = persistent_prepare_exception;
- store->commit_exception = persistent_commit_exception;
- store->drop_snapshot = persistent_drop_snapshot;
- store->fraction_full = persistent_fraction_full;
store->context = ps;
return 0;
}
+static unsigned persistent_status(struct dm_exception_store *store,
+ status_type_t status, char *result,
+ unsigned maxlen)
+{
+ unsigned sz = 0;
+
+ switch (status) {
+ case STATUSTYPE_INFO:
+ break;
+ case STATUSTYPE_TABLE:
+ DMEMIT(" %s P %llu", store->cow->name,
+ (unsigned long long)store->chunk_size);
+ }
+
+ return sz;
+}
+
+static struct dm_exception_store_type _persistent_type = {
+ .name = "persistent",
+ .module = THIS_MODULE,
+ .ctr = persistent_ctr,
+ .dtr = persistent_dtr,
+ .read_metadata = persistent_read_metadata,
+ .prepare_exception = persistent_prepare_exception,
+ .commit_exception = persistent_commit_exception,
+ .drop_snapshot = persistent_drop_snapshot,
+ .fraction_full = persistent_fraction_full,
+ .status = persistent_status,
+};
+
+static struct dm_exception_store_type _persistent_compat_type = {
+ .name = "P",
+ .module = THIS_MODULE,
+ .ctr = persistent_ctr,
+ .dtr = persistent_dtr,
+ .read_metadata = persistent_read_metadata,
+ .prepare_exception = persistent_prepare_exception,
+ .commit_exception = persistent_commit_exception,
+ .drop_snapshot = persistent_drop_snapshot,
+ .fraction_full = persistent_fraction_full,
+ .status = persistent_status,
+};
+
int dm_persistent_snapshot_init(void)
{
- return 0;
+ int r;
+
+ r = dm_exception_store_type_register(&_persistent_type);
+ if (r) {
+ DMERR("Unable to register persistent exception store type");
+ return r;
+ }
+
+ r = dm_exception_store_type_register(&_persistent_compat_type);
+ if (r) {
+ DMERR("Unable to register old-style persistent exception "
+ "store type");
+ dm_exception_store_type_unregister(&_persistent_type);
+ return r;
+ }
+
+ return r;
}
void dm_persistent_snapshot_exit(void)
{
+ dm_exception_store_type_unregister(&_persistent_type);
+ dm_exception_store_type_unregister(&_persistent_compat_type);
}
*/
#include "dm-exception-store.h"
-#include "dm-snap.h"
#include <linux/mm.h>
#include <linux/pagemap.h>
sector_t next_free;
};
-static void transient_destroy(struct dm_exception_store *store)
+static void transient_dtr(struct dm_exception_store *store)
{
kfree(store->context);
}
static int transient_prepare_exception(struct dm_exception_store *store,
struct dm_snap_exception *e)
{
- struct transient_c *tc = (struct transient_c *) store->context;
- sector_t size = get_dev_size(store->snap->cow->bdev);
+ struct transient_c *tc = store->context;
+ sector_t size = get_dev_size(store->cow->bdev);
- if (size < (tc->next_free + store->snap->chunk_size))
+ if (size < (tc->next_free + store->chunk_size))
return -1;
- e->new_chunk = sector_to_chunk(store->snap, tc->next_free);
- tc->next_free += store->snap->chunk_size;
+ e->new_chunk = sector_to_chunk(store, tc->next_free);
+ tc->next_free += store->chunk_size;
return 0;
}
sector_t *numerator, sector_t *denominator)
{
*numerator = ((struct transient_c *) store->context)->next_free;
- *denominator = get_dev_size(store->snap->cow->bdev);
+ *denominator = get_dev_size(store->cow->bdev);
}
-int dm_create_transient(struct dm_exception_store *store)
+static int transient_ctr(struct dm_exception_store *store,
+ unsigned argc, char **argv)
{
struct transient_c *tc;
- store->destroy = transient_destroy;
- store->read_metadata = transient_read_metadata;
- store->prepare_exception = transient_prepare_exception;
- store->commit_exception = transient_commit_exception;
- store->drop_snapshot = NULL;
- store->fraction_full = transient_fraction_full;
-
tc = kmalloc(sizeof(struct transient_c), GFP_KERNEL);
if (!tc)
return -ENOMEM;
return 0;
}
+static unsigned transient_status(struct dm_exception_store *store,
+ status_type_t status, char *result,
+ unsigned maxlen)
+{
+ unsigned sz = 0;
+
+ switch (status) {
+ case STATUSTYPE_INFO:
+ break;
+ case STATUSTYPE_TABLE:
+ DMEMIT(" %s N %llu", store->cow->name,
+ (unsigned long long)store->chunk_size);
+ }
+
+ return sz;
+}
+
+static struct dm_exception_store_type _transient_type = {
+ .name = "transient",
+ .module = THIS_MODULE,
+ .ctr = transient_ctr,
+ .dtr = transient_dtr,
+ .read_metadata = transient_read_metadata,
+ .prepare_exception = transient_prepare_exception,
+ .commit_exception = transient_commit_exception,
+ .fraction_full = transient_fraction_full,
+ .status = transient_status,
+};
+
+static struct dm_exception_store_type _transient_compat_type = {
+ .name = "N",
+ .module = THIS_MODULE,
+ .ctr = transient_ctr,
+ .dtr = transient_dtr,
+ .read_metadata = transient_read_metadata,
+ .prepare_exception = transient_prepare_exception,
+ .commit_exception = transient_commit_exception,
+ .fraction_full = transient_fraction_full,
+ .status = transient_status,
+};
+
int dm_transient_snapshot_init(void)
{
- return 0;
+ int r;
+
+ r = dm_exception_store_type_register(&_transient_type);
+ if (r) {
+ DMWARN("Unable to register transient exception store type");
+ return r;
+ }
+
+ r = dm_exception_store_type_register(&_transient_compat_type);
+ if (r) {
+ DMWARN("Unable to register old-style transient "
+ "exception store type");
+ dm_exception_store_type_unregister(&_transient_type);
+ return r;
+ }
+
+ return r;
}
void dm_transient_snapshot_exit(void)
{
+ dm_exception_store_type_unregister(&_transient_type);
+ dm_exception_store_type_unregister(&_transient_compat_type);
}
*/
#include <linux/blkdev.h>
-#include <linux/ctype.h>
#include <linux/device-mapper.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/vmalloc.h>
#include <linux/log2.h>
#include <linux/dm-kcopyd.h>
+#include <linux/workqueue.h>
#include "dm-exception-store.h"
-#include "dm-snap.h"
#include "dm-bio-list.h"
#define DM_MSG_PREFIX "snapshots"
*/
#define MIN_IOS 256
+#define DM_TRACKED_CHUNK_HASH_SIZE 16
+#define DM_TRACKED_CHUNK_HASH(x) ((unsigned long)(x) & \
+ (DM_TRACKED_CHUNK_HASH_SIZE - 1))
+
+struct exception_table {
+ uint32_t hash_mask;
+ unsigned hash_shift;
+ struct list_head *table;
+};
+
+struct dm_snapshot {
+ struct rw_semaphore lock;
+
+ struct dm_dev *origin;
+
+ /* List of snapshots per Origin */
+ struct list_head list;
+
+ /* You can't use a snapshot if this is 0 (e.g. if full) */
+ int valid;
+
+ /* Origin writes don't trigger exceptions until this is set */
+ int active;
+
+ mempool_t *pending_pool;
+
+ atomic_t pending_exceptions_count;
+
+ struct exception_table pending;
+ struct exception_table complete;
+
+ /*
+ * pe_lock protects all pending_exception operations and access
+ * as well as the snapshot_bios list.
+ */
+ spinlock_t pe_lock;
+
+ /* The on disk metadata handler */
+ struct dm_exception_store *store;
+
+ struct dm_kcopyd_client *kcopyd_client;
+
+ /* Queue of snapshot writes for ksnapd to flush */
+ struct bio_list queued_bios;
+ struct work_struct queued_bios_work;
+
+ /* Chunks with outstanding reads */
+ mempool_t *tracked_chunk_pool;
+ spinlock_t tracked_chunk_lock;
+ struct hlist_head tracked_chunk_hash[DM_TRACKED_CHUNK_HASH_SIZE];
+};
+
static struct workqueue_struct *ksnapd;
static void flush_queued_bios(struct work_struct *work);
+static sector_t chunk_to_sector(struct dm_exception_store *store,
+ chunk_t chunk)
+{
+ return chunk << store->chunk_shift;
+}
+
+static int bdev_equal(struct block_device *lhs, struct block_device *rhs)
+{
+ /*
+ * There is only ever one instance of a particular block
+ * device so we can compare pointers safely.
+ */
+ return lhs == rhs;
+}
+
struct dm_snap_pending_exception {
struct dm_snap_exception e;
* Calculate based on the size of the original volume or
* the COW volume...
*/
- cow_dev_size = get_dev_size(s->cow->bdev);
+ cow_dev_size = get_dev_size(s->store->cow->bdev);
origin_dev_size = get_dev_size(s->origin->bdev);
max_buckets = calc_max_buckets();
- hash_size = min(origin_dev_size, cow_dev_size) >> s->chunk_shift;
+ hash_size = min(origin_dev_size, cow_dev_size) >> s->store->chunk_shift;
hash_size = min(hash_size, max_buckets);
hash_size = rounddown_pow_of_two(hash_size);
return 0;
}
-/*
- * Round a number up to the nearest 'size' boundary. size must
- * be a power of 2.
- */
-static ulong round_up(ulong n, ulong size)
-{
- size--;
- return (n + size) & ~size;
-}
-
-static int set_chunk_size(struct dm_snapshot *s, const char *chunk_size_arg,
- char **error)
-{
- unsigned long chunk_size;
- char *value;
-
- chunk_size = simple_strtoul(chunk_size_arg, &value, 10);
- if (*chunk_size_arg == '\0' || *value != '\0') {
- *error = "Invalid chunk size";
- return -EINVAL;
- }
-
- if (!chunk_size) {
- s->chunk_size = s->chunk_mask = s->chunk_shift = 0;
- return 0;
- }
-
- /*
- * Chunk size must be multiple of page size. Silently
- * round up if it's not.
- */
- chunk_size = round_up(chunk_size, PAGE_SIZE >> 9);
-
- /* Check chunk_size is a power of 2 */
- if (!is_power_of_2(chunk_size)) {
- *error = "Chunk size is not a power of 2";
- return -EINVAL;
- }
-
- /* Validate the chunk size against the device block size */
- if (chunk_size % (bdev_hardsect_size(s->cow->bdev) >> 9)) {
- *error = "Chunk size is not a multiple of device blocksize";
- return -EINVAL;
- }
-
- s->chunk_size = chunk_size;
- s->chunk_mask = chunk_size - 1;
- s->chunk_shift = ffs(chunk_size) - 1;
-
- return 0;
-}
-
/*
* Construct a snapshot mapping: <origin_dev> <COW-dev> <p/n> <chunk-size>
*/
struct dm_snapshot *s;
int i;
int r = -EINVAL;
- char persistent;
char *origin_path;
- char *cow_path;
+ struct dm_exception_store *store;
+ unsigned args_used;
if (argc != 4) {
ti->error = "requires exactly 4 arguments";
r = -EINVAL;
- goto bad1;
+ goto bad_args;
}
origin_path = argv[0];
- cow_path = argv[1];
- persistent = toupper(*argv[2]);
+ argv++;
+ argc--;
- if (persistent != 'P' && persistent != 'N') {
- ti->error = "Persistent flag is not P or N";
+ r = dm_exception_store_create(ti, argc, argv, &args_used, &store);
+ if (r) {
+ ti->error = "Couldn't create exception store";
r = -EINVAL;
- goto bad1;
+ goto bad_args;
}
+ argv += args_used;
+ argc -= args_used;
+
s = kmalloc(sizeof(*s), GFP_KERNEL);
- if (s == NULL) {
+ if (!s) {
ti->error = "Cannot allocate snapshot context private "
"structure";
r = -ENOMEM;
- goto bad1;
+ goto bad_snap;
}
r = dm_get_device(ti, origin_path, 0, ti->len, FMODE_READ, &s->origin);
if (r) {
ti->error = "Cannot get origin device";
- goto bad2;
- }
-
- r = dm_get_device(ti, cow_path, 0, 0,
- FMODE_READ | FMODE_WRITE, &s->cow);
- if (r) {
- dm_put_device(ti, s->origin);
- ti->error = "Cannot get COW device";
- goto bad2;
+ goto bad_origin;
}
- r = set_chunk_size(s, argv[3], &ti->error);
- if (r)
- goto bad3;
-
- s->type = persistent;
-
+ s->store = store;
s->valid = 1;
s->active = 0;
atomic_set(&s->pending_exceptions_count, 0);
init_rwsem(&s->lock);
spin_lock_init(&s->pe_lock);
- s->ti = ti;
/* Allocate hash table for COW data */
if (init_hash_tables(s)) {
ti->error = "Unable to allocate hash table space";
r = -ENOMEM;
- goto bad3;
- }
-
- s->store.snap = s;
-
- if (persistent == 'P')
- r = dm_create_persistent(&s->store);
- else
- r = dm_create_transient(&s->store);
-
- if (r) {
- ti->error = "Couldn't create exception store";
- r = -EINVAL;
- goto bad4;
+ goto bad_hash_tables;
}
r = dm_kcopyd_client_create(SNAPSHOT_PAGES, &s->kcopyd_client);
if (r) {
ti->error = "Could not create kcopyd client";
- goto bad5;
+ goto bad_kcopyd;
}
s->pending_pool = mempool_create_slab_pool(MIN_IOS, pending_cache);
if (!s->pending_pool) {
ti->error = "Could not allocate mempool for pending exceptions";
- goto bad6;
+ goto bad_pending_pool;
}
s->tracked_chunk_pool = mempool_create_slab_pool(MIN_IOS,
spin_lock_init(&s->tracked_chunk_lock);
/* Metadata must only be loaded into one table at once */
- r = s->store.read_metadata(&s->store, dm_add_exception, (void *)s);
+ r = s->store->type->read_metadata(s->store, dm_add_exception,
+ (void *)s);
if (r < 0) {
ti->error = "Failed to read snapshot metadata";
goto bad_load_and_register;
}
ti->private = s;
- ti->split_io = s->chunk_size;
+ ti->split_io = s->store->chunk_size;
return 0;
- bad_load_and_register:
+bad_load_and_register:
mempool_destroy(s->tracked_chunk_pool);
- bad_tracked_chunk_pool:
+bad_tracked_chunk_pool:
mempool_destroy(s->pending_pool);
- bad6:
+bad_pending_pool:
dm_kcopyd_client_destroy(s->kcopyd_client);
- bad5:
- s->store.destroy(&s->store);
-
- bad4:
+bad_kcopyd:
exit_exception_table(&s->pending, pending_cache);
exit_exception_table(&s->complete, exception_cache);
- bad3:
- dm_put_device(ti, s->cow);
+bad_hash_tables:
dm_put_device(ti, s->origin);
- bad2:
+bad_origin:
kfree(s);
- bad1:
+bad_snap:
+ dm_exception_store_destroy(store);
+
+bad_args:
return r;
}
exit_exception_table(&s->pending, pending_cache);
exit_exception_table(&s->complete, exception_cache);
-
- s->store.destroy(&s->store);
}
static void snapshot_dtr(struct dm_target *ti)
mempool_destroy(s->pending_pool);
dm_put_device(ti, s->origin);
- dm_put_device(ti, s->cow);
+
+ dm_exception_store_destroy(s->store);
kfree(s);
}
else if (err == -ENOMEM)
DMERR("Invalidating snapshot: Unable to allocate exception.");
- if (s->store.drop_snapshot)
- s->store.drop_snapshot(&s->store);
+ if (s->store->type->drop_snapshot)
+ s->store->type->drop_snapshot(s->store);
s->valid = 0;
- dm_table_event(s->ti->table);
+ dm_table_event(s->store->ti->table);
}
static void get_pending_exception(struct dm_snap_pending_exception *pe)
else
/* Update the metadata if we are persistent */
- s->store.commit_exception(&s->store, &pe->e, commit_callback,
- pe);
+ s->store->type->commit_exception(s->store, &pe->e,
+ commit_callback, pe);
}
/*
dev_size = get_dev_size(bdev);
src.bdev = bdev;
- src.sector = chunk_to_sector(s, pe->e.old_chunk);
- src.count = min(s->chunk_size, dev_size - src.sector);
+ src.sector = chunk_to_sector(s->store, pe->e.old_chunk);
+ src.count = min(s->store->chunk_size, dev_size - src.sector);
- dest.bdev = s->cow->bdev;
- dest.sector = chunk_to_sector(s, pe->e.new_chunk);
+ dest.bdev = s->store->cow->bdev;
+ dest.sector = chunk_to_sector(s->store, pe->e.new_chunk);
dest.count = src.count;
/* Hand over to kcopyd */
&src, 1, &dest, 0, copy_callback, pe);
}
+static struct dm_snap_pending_exception *
+__lookup_pending_exception(struct dm_snapshot *s, chunk_t chunk)
+{
+ struct dm_snap_exception *e = lookup_exception(&s->pending, chunk);
+
+ if (!e)
+ return NULL;
+
+ return container_of(e, struct dm_snap_pending_exception, e);
+}
+
/*
* Looks to see if this snapshot already has a pending exception
* for this chunk, otherwise it allocates a new one and inserts
* this.
*/
static struct dm_snap_pending_exception *
-__find_pending_exception(struct dm_snapshot *s, struct bio *bio)
+__find_pending_exception(struct dm_snapshot *s,
+ struct dm_snap_pending_exception *pe, chunk_t chunk)
{
- struct dm_snap_exception *e;
- struct dm_snap_pending_exception *pe;
- chunk_t chunk = sector_to_chunk(s, bio->bi_sector);
+ struct dm_snap_pending_exception *pe2;
- /*
- * Is there a pending exception for this already ?
- */
- e = lookup_exception(&s->pending, chunk);
- if (e) {
- /* cast the exception to a pending exception */
- pe = container_of(e, struct dm_snap_pending_exception, e);
- goto out;
- }
-
- /*
- * Create a new pending exception, we don't want
- * to hold the lock while we do this.
- */
- up_write(&s->lock);
- pe = alloc_pending_exception(s);
- down_write(&s->lock);
-
- if (!s->valid) {
- free_pending_exception(pe);
- return NULL;
- }
-
- e = lookup_exception(&s->pending, chunk);
- if (e) {
+ pe2 = __lookup_pending_exception(s, chunk);
+ if (pe2) {
free_pending_exception(pe);
- pe = container_of(e, struct dm_snap_pending_exception, e);
- goto out;
+ return pe2;
}
pe->e.old_chunk = chunk;
atomic_set(&pe->ref_count, 0);
pe->started = 0;
- if (s->store.prepare_exception(&s->store, &pe->e)) {
+ if (s->store->type->prepare_exception(s->store, &pe->e)) {
free_pending_exception(pe);
return NULL;
}
get_pending_exception(pe);
insert_exception(&s->pending, &pe->e);
- out:
return pe;
}
static void remap_exception(struct dm_snapshot *s, struct dm_snap_exception *e,
struct bio *bio, chunk_t chunk)
{
- bio->bi_bdev = s->cow->bdev;
- bio->bi_sector = chunk_to_sector(s, dm_chunk_number(e->new_chunk) +
- (chunk - e->old_chunk)) +
- (bio->bi_sector & s->chunk_mask);
+ bio->bi_bdev = s->store->cow->bdev;
+ bio->bi_sector = chunk_to_sector(s->store,
+ dm_chunk_number(e->new_chunk) +
+ (chunk - e->old_chunk)) +
+ (bio->bi_sector &
+ s->store->chunk_mask);
}
static int snapshot_map(struct dm_target *ti, struct bio *bio,
chunk_t chunk;
struct dm_snap_pending_exception *pe = NULL;
- chunk = sector_to_chunk(s, bio->bi_sector);
+ chunk = sector_to_chunk(s->store, bio->bi_sector);
/* Full snapshots are not usable */
/* To get here the table must be live so s->active is always set. */
* writeable.
*/
if (bio_rw(bio) == WRITE) {
- pe = __find_pending_exception(s, bio);
+ pe = __lookup_pending_exception(s, chunk);
if (!pe) {
- __invalidate_snapshot(s, -ENOMEM);
- r = -EIO;
- goto out_unlock;
+ up_write(&s->lock);
+ pe = alloc_pending_exception(s);
+ down_write(&s->lock);
+
+ if (!s->valid) {
+ free_pending_exception(pe);
+ r = -EIO;
+ goto out_unlock;
+ }
+
+ e = lookup_exception(&s->complete, chunk);
+ if (e) {
+ free_pending_exception(pe);
+ remap_exception(s, e, bio, chunk);
+ goto out_unlock;
+ }
+
+ pe = __find_pending_exception(s, pe, chunk);
+ if (!pe) {
+ __invalidate_snapshot(s, -ENOMEM);
+ r = -EIO;
+ goto out_unlock;
+ }
}
remap_exception(s, &pe->e, bio, chunk);
static int snapshot_status(struct dm_target *ti, status_type_t type,
char *result, unsigned int maxlen)
{
+ unsigned sz = 0;
struct dm_snapshot *snap = ti->private;
switch (type) {
case STATUSTYPE_INFO:
if (!snap->valid)
- snprintf(result, maxlen, "Invalid");
+ DMEMIT("Invalid");
else {
- if (snap->store.fraction_full) {
+ if (snap->store->type->fraction_full) {
sector_t numerator, denominator;
- snap->store.fraction_full(&snap->store,
- &numerator,
- &denominator);
- snprintf(result, maxlen, "%llu/%llu",
- (unsigned long long)numerator,
- (unsigned long long)denominator);
+ snap->store->type->fraction_full(snap->store,
+ &numerator,
+ &denominator);
+ DMEMIT("%llu/%llu",
+ (unsigned long long)numerator,
+ (unsigned long long)denominator);
}
else
- snprintf(result, maxlen, "Unknown");
+ DMEMIT("Unknown");
}
break;
* to make private copies if the output is to
* make sense.
*/
- snprintf(result, maxlen, "%s %s %c %llu",
- snap->origin->name, snap->cow->name,
- snap->type,
- (unsigned long long)snap->chunk_size);
+ DMEMIT("%s", snap->origin->name);
+ snap->store->type->status(snap->store, type, result + sz,
+ maxlen - sz);
break;
}
goto next_snapshot;
/* Nothing to do if writing beyond end of snapshot */
- if (bio->bi_sector >= dm_table_get_size(snap->ti->table))
+ if (bio->bi_sector >= dm_table_get_size(snap->store->ti->table))
goto next_snapshot;
/*
* Remember, different snapshots can have
* different chunk sizes.
*/
- chunk = sector_to_chunk(snap, bio->bi_sector);
+ chunk = sector_to_chunk(snap->store, bio->bi_sector);
/*
* Check exception table to see if block
if (e)
goto next_snapshot;
- pe = __find_pending_exception(snap, bio);
+ pe = __lookup_pending_exception(snap, chunk);
if (!pe) {
- __invalidate_snapshot(snap, -ENOMEM);
- goto next_snapshot;
+ up_write(&snap->lock);
+ pe = alloc_pending_exception(snap);
+ down_write(&snap->lock);
+
+ if (!snap->valid) {
+ free_pending_exception(pe);
+ goto next_snapshot;
+ }
+
+ e = lookup_exception(&snap->complete, chunk);
+ if (e) {
+ free_pending_exception(pe);
+ goto next_snapshot;
+ }
+
+ pe = __find_pending_exception(snap, pe, chunk);
+ if (!pe) {
+ __invalidate_snapshot(snap, -ENOMEM);
+ goto next_snapshot;
+ }
}
if (!primary_pe) {
o = __lookup_origin(dev->bdev);
if (o)
list_for_each_entry (snap, &o->snapshots, list)
- chunk_size = min_not_zero(chunk_size, snap->chunk_size);
+ chunk_size = min_not_zero(chunk_size,
+ snap->store->chunk_size);
up_read(&_origins_lock);
ti->split_io = chunk_size;
+++ /dev/null
-/*
- * Copyright (C) 2001-2002 Sistina Software (UK) Limited.
- *
- * This file is released under the GPL.
- */
-
-#ifndef DM_SNAPSHOT_H
-#define DM_SNAPSHOT_H
-
-#include <linux/device-mapper.h>
-#include "dm-exception-store.h"
-#include "dm-bio-list.h"
-#include <linux/blkdev.h>
-#include <linux/workqueue.h>
-
-struct exception_table {
- uint32_t hash_mask;
- unsigned hash_shift;
- struct list_head *table;
-};
-
-#define DM_TRACKED_CHUNK_HASH_SIZE 16
-#define DM_TRACKED_CHUNK_HASH(x) ((unsigned long)(x) & \
- (DM_TRACKED_CHUNK_HASH_SIZE - 1))
-
-struct dm_snapshot {
- struct rw_semaphore lock;
- struct dm_target *ti;
-
- struct dm_dev *origin;
- struct dm_dev *cow;
-
- /* List of snapshots per Origin */
- struct list_head list;
-
- /* Size of data blocks saved - must be a power of 2 */
- chunk_t chunk_size;
- chunk_t chunk_mask;
- chunk_t chunk_shift;
-
- /* You can't use a snapshot if this is 0 (e.g. if full) */
- int valid;
-
- /* Origin writes don't trigger exceptions until this is set */
- int active;
-
- /* Used for display of table */
- char type;
-
- mempool_t *pending_pool;
-
- atomic_t pending_exceptions_count;
-
- struct exception_table pending;
- struct exception_table complete;
-
- /*
- * pe_lock protects all pending_exception operations and access
- * as well as the snapshot_bios list.
- */
- spinlock_t pe_lock;
-
- /* The on disk metadata handler */
- struct dm_exception_store store;
-
- struct dm_kcopyd_client *kcopyd_client;
-
- /* Queue of snapshot writes for ksnapd to flush */
- struct bio_list queued_bios;
- struct work_struct queued_bios_work;
-
- /* Chunks with outstanding reads */
- mempool_t *tracked_chunk_pool;
- spinlock_t tracked_chunk_lock;
- struct hlist_head tracked_chunk_hash[DM_TRACKED_CHUNK_HASH_SIZE];
-};
-
-/*
- * Return the number of sectors in the device.
- */
-static inline sector_t get_dev_size(struct block_device *bdev)
-{
- return bdev->bd_inode->i_size >> SECTOR_SHIFT;
-}
-
-static inline chunk_t sector_to_chunk(struct dm_snapshot *s, sector_t sector)
-{
- return (sector & ~s->chunk_mask) >> s->chunk_shift;
-}
-
-static inline sector_t chunk_to_sector(struct dm_snapshot *s, chunk_t chunk)
-{
- return chunk << s->chunk_shift;
-}
-
-static inline int bdev_equal(struct block_device *lhs, struct block_device *rhs)
-{
- /*
- * There is only ever one instance of a particular block
- * device so we can compare pointers safely.
- */
- return lhs == rhs;
-}
-
-#endif
}
/*
- * This upgrades the mode on an already open dm_dev. Being
+ * This upgrades the mode on an already open dm_dev, being
* careful to leave things as they were if we fail to reopen the
- * device.
+ * device and not to touch the existing bdev field in case
+ * it is accessed concurrently inside dm_table_any_congested().
*/
static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
struct mapped_device *md)
{
int r;
- struct dm_dev_internal dd_copy;
- dev_t dev = dd->dm_dev.bdev->bd_dev;
+ struct dm_dev_internal dd_new, dd_old;
- dd_copy = *dd;
+ 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;
dd->dm_dev.mode |= new_mode;
- dd->dm_dev.bdev = NULL;
- r = open_dev(dd, dev, md);
- if (!r)
- close_dev(&dd_copy, md);
- else
- *dd = dd_copy;
+ close_dev(&dd_old, md);
- return r;
+ return 0;
}
/*
#define DM_MSG_PREFIX "target"
-struct tt_internal {
- struct target_type tt;
-
- struct list_head list;
- long use;
-};
-
static LIST_HEAD(_targets);
static DECLARE_RWSEM(_lock);
#define DM_MOD_NAME_SIZE 32
-static inline struct tt_internal *__find_target_type(const char *name)
+static inline struct target_type *__find_target_type(const char *name)
{
- struct tt_internal *ti;
+ struct target_type *tt;
- list_for_each_entry (ti, &_targets, list)
- if (!strcmp(name, ti->tt.name))
- return ti;
+ list_for_each_entry(tt, &_targets, list)
+ if (!strcmp(name, tt->name))
+ return tt;
return NULL;
}
-static struct tt_internal *get_target_type(const char *name)
+static struct target_type *get_target_type(const char *name)
{
- struct tt_internal *ti;
+ struct target_type *tt;
down_read(&_lock);
- ti = __find_target_type(name);
- if (ti) {
- if ((ti->use == 0) && !try_module_get(ti->tt.module))
- ti = NULL;
- else
- ti->use++;
- }
+ tt = __find_target_type(name);
+ if (tt && !try_module_get(tt->module))
+ tt = NULL;
up_read(&_lock);
- return ti;
+ return tt;
}
static void load_module(const char *name)
struct target_type *dm_get_target_type(const char *name)
{
- struct tt_internal *ti = get_target_type(name);
+ struct target_type *tt = get_target_type(name);
- if (!ti) {
+ if (!tt) {
load_module(name);
- ti = get_target_type(name);
+ tt = get_target_type(name);
}
- return ti ? &ti->tt : NULL;
+ return tt;
}
-void dm_put_target_type(struct target_type *t)
+void dm_put_target_type(struct target_type *tt)
{
- struct tt_internal *ti = (struct tt_internal *) t;
-
down_read(&_lock);
- if (--ti->use == 0)
- module_put(ti->tt.module);
-
- BUG_ON(ti->use < 0);
+ module_put(tt->module);
up_read(&_lock);
-
- return;
-}
-
-static struct tt_internal *alloc_target(struct target_type *t)
-{
- struct tt_internal *ti = kzalloc(sizeof(*ti), GFP_KERNEL);
-
- if (ti)
- ti->tt = *t;
-
- return ti;
}
-
int dm_target_iterate(void (*iter_func)(struct target_type *tt,
void *param), void *param)
{
- struct tt_internal *ti;
+ struct target_type *tt;
down_read(&_lock);
- list_for_each_entry (ti, &_targets, list)
- iter_func(&ti->tt, param);
+ list_for_each_entry(tt, &_targets, list)
+ iter_func(tt, param);
up_read(&_lock);
return 0;
}
-int dm_register_target(struct target_type *t)
+int dm_register_target(struct target_type *tt)
{
int rv = 0;
- struct tt_internal *ti = alloc_target(t);
-
- if (!ti)
- return -ENOMEM;
down_write(&_lock);
- if (__find_target_type(t->name))
+ if (__find_target_type(tt->name))
rv = -EEXIST;
else
- list_add(&ti->list, &_targets);
+ list_add(&tt->list, &_targets);
up_write(&_lock);
- if (rv)
- kfree(ti);
return rv;
}
-void dm_unregister_target(struct target_type *t)
+void dm_unregister_target(struct target_type *tt)
{
- struct tt_internal *ti;
-
down_write(&_lock);
- if (!(ti = __find_target_type(t->name))) {
- DMCRIT("Unregistering unrecognised target: %s", t->name);
- BUG();
- }
-
- if (ti->use) {
- DMCRIT("Attempt to unregister target still in use: %s",
- t->name);
+ if (!__find_target_type(tt->name)) {
+ DMCRIT("Unregistering unrecognised target: %s", tt->name);
BUG();
}
- list_del(&ti->list);
- kfree(ti);
+ list_del(&tt->list);
up_write(&_lock);
}
* io-err: always fails an io, useful for bringing
* up LVs that have holes in them.
*/
-static int io_err_ctr(struct dm_target *ti, unsigned int argc, char **args)
+static int io_err_ctr(struct dm_target *tt, unsigned int argc, char **args)
{
return 0;
}
-static void io_err_dtr(struct dm_target *ti)
+static void io_err_dtr(struct dm_target *tt)
{
/* empty */
}
-static int io_err_map(struct dm_target *ti, struct bio *bio,
+static int io_err_map(struct dm_target *tt, struct bio *bio,
union map_info *map_context)
{
return -EIO;
/*
* Work processed by per-device workqueue.
*/
-struct dm_wq_req {
- enum {
- DM_WQ_FLUSH_DEFERRED,
- } type;
- struct work_struct work;
- struct mapped_device *md;
- void *context;
-};
-
struct mapped_device {
struct rw_semaphore io_lock;
struct mutex suspend_lock;
- spinlock_t pushback_lock;
rwlock_t map_lock;
atomic_t holders;
atomic_t open_count;
*/
atomic_t pending;
wait_queue_head_t wait;
+ struct work_struct work;
struct bio_list deferred;
- struct bio_list pushback;
+ spinlock_t deferred_lock;
/*
* Processing queue (flush/barriers)
return 1;
}
+ spin_lock_irq(&md->deferred_lock);
bio_list_add(&md->deferred, bio);
+ spin_unlock_irq(&md->deferred_lock);
up_write(&md->io_lock);
return 0; /* deferred successfully */
if (io->error == DM_ENDIO_REQUEUE) {
/*
* Target requested pushing back the I/O.
- * This must be handled before the sleeper on
- * suspend queue merges the pushback list.
*/
- spin_lock_irqsave(&md->pushback_lock, flags);
+ spin_lock_irqsave(&md->deferred_lock, flags);
if (__noflush_suspending(md))
- bio_list_add(&md->pushback, io->bio);
+ bio_list_add(&md->deferred, io->bio);
else
/* noflush suspend was interrupted. */
io->error = -EIO;
- spin_unlock_irqrestore(&md->pushback_lock, flags);
+ spin_unlock_irqrestore(&md->deferred_lock, flags);
}
end_io_acct(io);
}
/*
- * Split the bio into several clones.
+ * Split the bio into several clones and submit it to targets.
*/
-static int __split_bio(struct mapped_device *md, struct bio *bio)
+static void __split_and_process_bio(struct mapped_device *md, struct bio *bio)
{
struct clone_info ci;
int error = 0;
ci.map = dm_get_table(md);
- if (unlikely(!ci.map))
- return -EIO;
+ if (unlikely(!ci.map)) {
+ bio_io_error(bio);
+ return;
+ }
if (unlikely(bio_barrier(bio) && !dm_table_barrier_ok(ci.map))) {
dm_table_put(ci.map);
bio_endio(bio, -EOPNOTSUPP);
- return 0;
+ return;
}
ci.md = md;
ci.bio = bio;
/* drop the extra reference count */
dec_pending(ci.io, error);
dm_table_put(ci.map);
-
- return 0;
}
/*-----------------------------------------------------------------
* CRUD END
down_read(&md->io_lock);
}
- r = __split_bio(md, bio);
+ __split_and_process_bio(md, bio);
up_read(&md->io_lock);
+ return 0;
out_req:
if (r < 0)
static struct block_device_operations dm_blk_dops;
+static void dm_wq_work(struct work_struct *work);
+
/*
* Allocate and initialise a blank device with a given minor.
*/
init_rwsem(&md->io_lock);
mutex_init(&md->suspend_lock);
- spin_lock_init(&md->pushback_lock);
+ spin_lock_init(&md->deferred_lock);
rwlock_init(&md->map_lock);
atomic_set(&md->holders, 1);
atomic_set(&md->open_count, 0);
md->queue->backing_dev_info.congested_fn = dm_any_congested;
md->queue->backing_dev_info.congested_data = md;
blk_queue_make_request(md->queue, dm_request);
+ blk_queue_ordered(md->queue, QUEUE_ORDERED_DRAIN, NULL);
blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
md->queue->unplug_fn = dm_unplug_all;
blk_queue_merge_bvec(md->queue, dm_merge_bvec);
atomic_set(&md->pending, 0);
init_waitqueue_head(&md->wait);
+ INIT_WORK(&md->work, dm_wq_work);
init_waitqueue_head(&md->eventq);
md->disk->major = _major;
}
EXPORT_SYMBOL_GPL(dm_put);
-static int dm_wait_for_completion(struct mapped_device *md)
+static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
{
int r = 0;
+ DECLARE_WAITQUEUE(wait, current);
+
+ dm_unplug_all(md->queue);
+
+ add_wait_queue(&md->wait, &wait);
while (1) {
- set_current_state(TASK_INTERRUPTIBLE);
+ set_current_state(interruptible);
smp_mb();
if (!atomic_read(&md->pending))
break;
- if (signal_pending(current)) {
+ if (interruptible == TASK_INTERRUPTIBLE &&
+ signal_pending(current)) {
r = -EINTR;
break;
}
}
set_current_state(TASK_RUNNING);
+ remove_wait_queue(&md->wait, &wait);
+
return r;
}
/*
* Process the deferred bios
*/
-static void __flush_deferred_io(struct mapped_device *md)
+static void dm_wq_work(struct work_struct *work)
{
+ struct mapped_device *md = container_of(work, struct mapped_device,
+ work);
struct bio *c;
- while ((c = bio_list_pop(&md->deferred))) {
- if (__split_bio(md, c))
- bio_io_error(c);
- }
-
- clear_bit(DMF_BLOCK_IO, &md->flags);
-}
+ down_write(&md->io_lock);
-static void __merge_pushback_list(struct mapped_device *md)
-{
- unsigned long flags;
+next_bio:
+ spin_lock_irq(&md->deferred_lock);
+ c = bio_list_pop(&md->deferred);
+ spin_unlock_irq(&md->deferred_lock);
- spin_lock_irqsave(&md->pushback_lock, flags);
- clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
- bio_list_merge_head(&md->deferred, &md->pushback);
- bio_list_init(&md->pushback);
- spin_unlock_irqrestore(&md->pushback_lock, flags);
-}
+ if (c) {
+ __split_and_process_bio(md, c);
+ goto next_bio;
+ }
-static void dm_wq_work(struct work_struct *work)
-{
- struct dm_wq_req *req = container_of(work, struct dm_wq_req, work);
- struct mapped_device *md = req->md;
+ clear_bit(DMF_BLOCK_IO, &md->flags);
- down_write(&md->io_lock);
- switch (req->type) {
- case DM_WQ_FLUSH_DEFERRED:
- __flush_deferred_io(md);
- break;
- default:
- DMERR("dm_wq_work: unrecognised work type %d", req->type);
- BUG();
- }
up_write(&md->io_lock);
}
-static void dm_wq_queue(struct mapped_device *md, int type, void *context,
- struct dm_wq_req *req)
-{
- req->type = type;
- req->md = md;
- req->context = context;
- INIT_WORK(&req->work, dm_wq_work);
- queue_work(md->wq, &req->work);
-}
-
-static void dm_queue_flush(struct mapped_device *md, int type, void *context)
+static void dm_queue_flush(struct mapped_device *md)
{
- struct dm_wq_req req;
-
- dm_wq_queue(md, type, context, &req);
+ queue_work(md->wq, &md->work);
flush_workqueue(md->wq);
}
int dm_suspend(struct mapped_device *md, unsigned suspend_flags)
{
struct dm_table *map = NULL;
- DECLARE_WAITQUEUE(wait, current);
int r = 0;
int do_lockfs = suspend_flags & DM_SUSPEND_LOCKFS_FLAG ? 1 : 0;
int noflush = suspend_flags & DM_SUSPEND_NOFLUSH_FLAG ? 1 : 0;
down_write(&md->io_lock);
set_bit(DMF_BLOCK_IO, &md->flags);
- add_wait_queue(&md->wait, &wait);
up_write(&md->io_lock);
- /* unplug */
- if (map)
- dm_table_unplug_all(map);
-
/*
* Wait for the already-mapped ios to complete.
*/
- r = dm_wait_for_completion(md);
+ r = dm_wait_for_completion(md, TASK_INTERRUPTIBLE);
down_write(&md->io_lock);
- remove_wait_queue(&md->wait, &wait);
if (noflush)
- __merge_pushback_list(md);
+ clear_bit(DMF_NOFLUSH_SUSPENDING, &md->flags);
up_write(&md->io_lock);
/* were we interrupted ? */
if (r < 0) {
- dm_queue_flush(md, DM_WQ_FLUSH_DEFERRED, NULL);
+ dm_queue_flush(md);
unlock_fs(md);
goto out; /* pushback list is already flushed, so skip flush */
if (r)
goto out;
- dm_queue_flush(md, DM_WQ_FLUSH_DEFERRED, NULL);
+ dm_queue_flush(md);
unlock_fs(md);
int dm_target_init(void);
void dm_target_exit(void);
struct target_type *dm_get_target_type(const char *name);
-void dm_put_target_type(struct target_type *t);
+void dm_put_target_type(struct target_type *tt);
int dm_target_iterate(void (*iter_func)(struct target_type *tt,
void *param), void *param);
dm_ioctl_fn ioctl;
dm_merge_fn merge;
dm_busy_fn busy;
+
+ /* For internal device-mapper use. */
+ struct list_head list;
};
struct io_restrictions {
const char *name;
struct module *module;
+ /* For internal device-mapper use */
+ struct list_head list;
+
int (*ctr)(struct dm_dirty_log *log, struct dm_target *ti,
unsigned argc, char **argv);
void (*dtr)(struct dm_dirty_log *log);
*/
int (*status)(struct dm_dirty_log *log, status_type_t status_type,
char *result, unsigned maxlen);
+
+ /*
+ * is_remote_recovering is necessary for cluster mirroring. It provides
+ * a way to detect recovery on another node, so we aren't writing
+ * concurrently. This function is likely to block (when a cluster log
+ * is used).
+ *
+ * Returns: 0, 1
+ */
+ int (*is_remote_recovering)(struct dm_dirty_log *log, region_t region);
};
int dm_dirty_log_type_register(struct dm_dirty_log_type *type);
projects / linux-2.6-omap-h63xx.git / commitdiff