dm snapshot: move ctr parsing to exception store
First step of having the exception stores parse their own arguments - generalizing the interface. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Jonathan Brassow
Alasdair G Kergon
parent
2e4a31df2b
commit
fee1998e9c
3 changed files with 132 additions and 129 deletions
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@ -7,6 +7,7 @@
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#include "dm-exception-store.h"
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#include <linux/ctype.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <linux/vmalloc.h>
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@ -137,49 +138,129 @@ int dm_exception_store_type_unregister(struct dm_exception_store_type *type)
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}
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EXPORT_SYMBOL(dm_exception_store_type_unregister);
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int dm_exception_store_create(const char *type_name, struct dm_target *ti,
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chunk_t chunk_size, chunk_t chunk_mask,
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chunk_t chunk_shift, struct dm_dev *cow,
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/*
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* Round a number up to the nearest 'size' boundary. size must
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* be a power of 2.
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*/
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static ulong round_up(ulong n, ulong size)
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{
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size--;
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return (n + size) & ~size;
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}
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static int set_chunk_size(struct dm_exception_store *store,
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const char *chunk_size_arg, char **error)
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{
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unsigned long chunk_size_ulong;
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char *value;
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chunk_size_ulong = simple_strtoul(chunk_size_arg, &value, 10);
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if (*chunk_size_arg == '\0' || *value != '\0') {
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*error = "Invalid chunk size";
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return -EINVAL;
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}
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if (!chunk_size_ulong) {
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store->chunk_size = store->chunk_mask = store->chunk_shift = 0;
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return 0;
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}
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/*
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* Chunk size must be multiple of page size. Silently
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* round up if it's not.
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*/
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chunk_size_ulong = round_up(chunk_size_ulong, PAGE_SIZE >> 9);
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/* Check chunk_size is a power of 2 */
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if (!is_power_of_2(chunk_size_ulong)) {
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*error = "Chunk size is not a power of 2";
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return -EINVAL;
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}
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/* Validate the chunk size against the device block size */
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if (chunk_size_ulong % (bdev_hardsect_size(store->cow->bdev) >> 9)) {
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*error = "Chunk size is not a multiple of device blocksize";
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return -EINVAL;
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}
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store->chunk_size = chunk_size_ulong;
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store->chunk_mask = chunk_size_ulong - 1;
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store->chunk_shift = ffs(chunk_size_ulong) - 1;
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return 0;
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}
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int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
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unsigned *args_used,
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struct dm_exception_store **store)
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{
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int r = 0;
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struct dm_exception_store_type *type;
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struct dm_exception_store *tmp_store;
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char persistent;
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if (argc < 3) {
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ti->error = "Insufficient exception store arguments";
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return -EINVAL;
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}
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tmp_store = kmalloc(sizeof(*tmp_store), GFP_KERNEL);
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if (!tmp_store)
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if (!tmp_store) {
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ti->error = "Exception store allocation failed";
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return -ENOMEM;
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}
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type = get_type(type_name);
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if (!type) {
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kfree(tmp_store);
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persistent = toupper(*argv[1]);
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if (persistent != 'P' && persistent != 'N') {
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ti->error = "Persistent flag is not P or N";
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return -EINVAL;
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}
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type = get_type(argv[1]);
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if (!type) {
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ti->error = "Exception store type not recognised";
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r = -EINVAL;
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goto bad_type;
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}
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tmp_store->type = type;
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tmp_store->ti = ti;
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tmp_store->chunk_size = chunk_size;
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tmp_store->chunk_mask = chunk_mask;
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tmp_store->chunk_shift = chunk_shift;
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r = dm_get_device(ti, argv[0], 0, 0,
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FMODE_READ | FMODE_WRITE, &tmp_store->cow);
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if (r) {
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ti->error = "Cannot get COW device";
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goto bad_cow;
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}
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tmp_store->cow = cow;
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r = set_chunk_size(tmp_store, argv[2], &ti->error);
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if (r)
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goto bad_cow;
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r = type->ctr(tmp_store, 0, NULL);
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if (r) {
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put_type(type);
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kfree(tmp_store);
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return r;
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ti->error = "Exception store type constructor failed";
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goto bad_ctr;
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}
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*args_used = 3;
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*store = tmp_store;
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return 0;
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bad_ctr:
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dm_put_device(ti, tmp_store->cow);
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bad_cow:
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put_type(type);
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bad_type:
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kfree(tmp_store);
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return r;
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}
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EXPORT_SYMBOL(dm_exception_store_create);
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void dm_exception_store_destroy(struct dm_exception_store *store)
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{
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store->type->dtr(store);
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dm_put_device(store->ti, store->cow);
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put_type(store->type);
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kfree(store);
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}
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@ -167,9 +167,8 @@ static inline chunk_t sector_to_chunk(struct dm_exception_store *store,
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int dm_exception_store_type_register(struct dm_exception_store_type *type);
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int dm_exception_store_type_unregister(struct dm_exception_store_type *type);
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int dm_exception_store_create(const char *type_name, struct dm_target *ti,
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chunk_t chunk_size, chunk_t chunk_mask,
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chunk_t chunk_shift, struct dm_dev *cow,
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int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
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unsigned *args_used,
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struct dm_exception_store **store);
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void dm_exception_store_destroy(struct dm_exception_store *store);
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@ -7,7 +7,6 @@
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*/
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#include <linux/blkdev.h>
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#include <linux/ctype.h>
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#include <linux/device-mapper.h>
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#include <linux/delay.h>
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#include <linux/fs.h>
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@ -538,8 +537,7 @@ static int calc_max_buckets(void)
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/*
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* Allocate room for a suitable hash table.
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*/
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static int init_hash_tables(struct dm_snapshot *s, chunk_t chunk_shift,
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struct dm_dev *cow)
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static int init_hash_tables(struct dm_snapshot *s)
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{
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sector_t hash_size, cow_dev_size, origin_dev_size, max_buckets;
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@ -547,11 +545,11 @@ static int init_hash_tables(struct dm_snapshot *s, chunk_t chunk_shift,
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* Calculate based on the size of the original volume or
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* the COW volume...
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*/
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cow_dev_size = get_dev_size(cow->bdev);
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cow_dev_size = get_dev_size(s->store->cow->bdev);
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origin_dev_size = get_dev_size(s->origin->bdev);
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max_buckets = calc_max_buckets();
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hash_size = min(origin_dev_size, cow_dev_size) >> chunk_shift;
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hash_size = min(origin_dev_size, cow_dev_size) >> s->store->chunk_shift;
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hash_size = min(hash_size, max_buckets);
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hash_size = rounddown_pow_of_two(hash_size);
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@ -575,60 +573,6 @@ static int init_hash_tables(struct dm_snapshot *s, chunk_t chunk_shift,
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return 0;
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}
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/*
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* Round a number up to the nearest 'size' boundary. size must
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* be a power of 2.
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*/
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static ulong round_up(ulong n, ulong size)
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{
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size--;
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return (n + size) & ~size;
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}
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static int set_chunk_size(struct dm_snapshot *s, const char *chunk_size_arg,
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chunk_t *chunk_size, chunk_t *chunk_mask,
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chunk_t *chunk_shift, struct dm_dev *cow,
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char **error)
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{
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unsigned long chunk_size_ulong;
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char *value;
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chunk_size_ulong = simple_strtoul(chunk_size_arg, &value, 10);
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if (*chunk_size_arg == '\0' || *value != '\0') {
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*error = "Invalid chunk size";
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return -EINVAL;
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}
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if (!chunk_size_ulong) {
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*chunk_size = *chunk_mask = *chunk_shift = 0;
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return 0;
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}
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/*
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* Chunk size must be multiple of page size. Silently
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* round up if it's not.
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*/
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chunk_size_ulong = round_up(chunk_size_ulong, PAGE_SIZE >> 9);
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/* Check chunk_size is a power of 2 */
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if (!is_power_of_2(chunk_size_ulong)) {
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*error = "Chunk size is not a power of 2";
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return -EINVAL;
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}
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/* Validate the chunk size against the device block size */
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if (chunk_size_ulong % (bdev_hardsect_size(cow->bdev) >> 9)) {
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*error = "Chunk size is not a multiple of device blocksize";
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return -EINVAL;
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}
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*chunk_size = chunk_size_ulong;
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*chunk_mask = chunk_size_ulong - 1;
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*chunk_shift = ffs(chunk_size_ulong) - 1;
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return 0;
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}
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/*
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* Construct a snapshot mapping: <origin_dev> <COW-dev> <p/n> <chunk-size>
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*/
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@ -637,55 +581,45 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
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struct dm_snapshot *s;
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int i;
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int r = -EINVAL;
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char persistent;
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char *origin_path;
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char *cow_path;
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chunk_t chunk_size, chunk_mask, chunk_shift;
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struct dm_dev *cow;
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struct dm_exception_store *store;
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unsigned args_used;
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if (argc != 4) {
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ti->error = "requires exactly 4 arguments";
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r = -EINVAL;
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goto bad1;
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goto bad_args;
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}
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origin_path = argv[0];
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cow_path = argv[1];
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persistent = toupper(*argv[2]);
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argv++;
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argc--;
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if (persistent != 'P' && persistent != 'N') {
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ti->error = "Persistent flag is not P or N";
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r = dm_exception_store_create(ti, argc, argv, &args_used, &store);
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if (r) {
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ti->error = "Couldn't create exception store";
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r = -EINVAL;
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goto bad1;
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goto bad_args;
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}
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argv += args_used;
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argc -= args_used;
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s = kmalloc(sizeof(*s), GFP_KERNEL);
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if (s == NULL) {
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if (!s) {
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ti->error = "Cannot allocate snapshot context private "
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"structure";
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r = -ENOMEM;
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goto bad1;
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goto bad_snap;
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}
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r = dm_get_device(ti, origin_path, 0, ti->len, FMODE_READ, &s->origin);
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if (r) {
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ti->error = "Cannot get origin device";
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goto bad2;
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goto bad_origin;
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}
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r = dm_get_device(ti, cow_path, 0, 0,
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FMODE_READ | FMODE_WRITE, &cow);
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if (r) {
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dm_put_device(ti, s->origin);
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ti->error = "Cannot get COW device";
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goto bad2;
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}
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r = set_chunk_size(s, argv[3], &chunk_size, &chunk_mask, &chunk_shift,
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cow, &ti->error);
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if (r)
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goto bad3;
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s->store = store;
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s->valid = 1;
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s->active = 0;
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atomic_set(&s->pending_exceptions_count, 0);
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@ -693,30 +627,22 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
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spin_lock_init(&s->pe_lock);
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/* Allocate hash table for COW data */
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if (init_hash_tables(s, chunk_shift, cow)) {
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if (init_hash_tables(s)) {
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ti->error = "Unable to allocate hash table space";
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r = -ENOMEM;
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goto bad3;
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}
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r = dm_exception_store_create(argv[2], ti, chunk_size, chunk_mask,
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chunk_shift, cow, &s->store);
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if (r) {
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ti->error = "Couldn't create exception store";
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r = -EINVAL;
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goto bad4;
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goto bad_hash_tables;
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}
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r = dm_kcopyd_client_create(SNAPSHOT_PAGES, &s->kcopyd_client);
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if (r) {
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ti->error = "Could not create kcopyd client";
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goto bad5;
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goto bad_kcopyd;
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}
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s->pending_pool = mempool_create_slab_pool(MIN_IOS, pending_cache);
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if (!s->pending_pool) {
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ti->error = "Could not allocate mempool for pending exceptions";
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goto bad6;
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goto bad_pending_pool;
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}
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s->tracked_chunk_pool = mempool_create_slab_pool(MIN_IOS,
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@ -759,30 +685,29 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
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return 0;
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bad_load_and_register:
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bad_load_and_register:
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mempool_destroy(s->tracked_chunk_pool);
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bad_tracked_chunk_pool:
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bad_tracked_chunk_pool:
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mempool_destroy(s->pending_pool);
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bad6:
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bad_pending_pool:
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dm_kcopyd_client_destroy(s->kcopyd_client);
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bad5:
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s->store->type->dtr(s->store);
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bad4:
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bad_kcopyd:
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exit_exception_table(&s->pending, pending_cache);
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exit_exception_table(&s->complete, exception_cache);
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bad3:
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dm_put_device(ti, cow);
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bad_hash_tables:
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dm_put_device(ti, s->origin);
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bad2:
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bad_origin:
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kfree(s);
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bad1:
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bad_snap:
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dm_exception_store_destroy(store);
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bad_args:
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return r;
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}
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@ -793,8 +718,6 @@ static void __free_exceptions(struct dm_snapshot *s)
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exit_exception_table(&s->pending, pending_cache);
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exit_exception_table(&s->complete, exception_cache);
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s->store->type->dtr(s->store);
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}
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static void snapshot_dtr(struct dm_target *ti)
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@ -803,7 +726,6 @@ static void snapshot_dtr(struct dm_target *ti)
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int i;
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#endif
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struct dm_snapshot *s = ti->private;
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struct dm_dev *cow = s->store->cow;
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flush_workqueue(ksnapd);
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@ -831,7 +753,8 @@ static void snapshot_dtr(struct dm_target *ti)
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mempool_destroy(s->pending_pool);
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dm_put_device(ti, s->origin);
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dm_put_device(ti, cow);
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dm_exception_store_destroy(s->store);
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kfree(s);
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}
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