From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- drivers/md/dm-log.c | 711 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 711 insertions(+) create mode 100644 drivers/md/dm-log.c (limited to 'drivers/md/dm-log.c') diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c new file mode 100644 index 00000000000..e110655eabd --- /dev/null +++ b/drivers/md/dm-log.c @@ -0,0 +1,711 @@ +/* + * Copyright (C) 2003 Sistina Software + * + * This file is released under the LGPL. + */ + +#include +#include +#include +#include + +#include "dm-log.h" +#include "dm-io.h" + +static LIST_HEAD(_log_types); +static DEFINE_SPINLOCK(_lock); + +int dm_register_dirty_log_type(struct dirty_log_type *type) +{ + spin_lock(&_lock); + type->use_count = 0; + list_add(&type->list, &_log_types); + spin_unlock(&_lock); + + return 0; +} + +int dm_unregister_dirty_log_type(struct dirty_log_type *type) +{ + spin_lock(&_lock); + + if (type->use_count) + DMWARN("Attempt to unregister a log type that is still in use"); + else + list_del(&type->list); + + spin_unlock(&_lock); + + return 0; +} + +static struct dirty_log_type *get_type(const char *type_name) +{ + struct dirty_log_type *type; + + spin_lock(&_lock); + list_for_each_entry (type, &_log_types, list) + if (!strcmp(type_name, type->name)) { + if (!type->use_count && !try_module_get(type->module)){ + spin_unlock(&_lock); + return NULL; + } + type->use_count++; + spin_unlock(&_lock); + return type; + } + + spin_unlock(&_lock); + return NULL; +} + +static void put_type(struct dirty_log_type *type) +{ + spin_lock(&_lock); + if (!--type->use_count) + module_put(type->module); + spin_unlock(&_lock); +} + +struct dirty_log *dm_create_dirty_log(const char *type_name, struct dm_target *ti, + unsigned int argc, char **argv) +{ + struct dirty_log_type *type; + struct dirty_log *log; + + log = kmalloc(sizeof(*log), GFP_KERNEL); + if (!log) + return NULL; + + type = get_type(type_name); + if (!type) { + kfree(log); + return NULL; + } + + log->type = type; + if (type->ctr(log, ti, argc, argv)) { + kfree(log); + put_type(type); + return NULL; + } + + return log; +} + +void dm_destroy_dirty_log(struct dirty_log *log) +{ + log->type->dtr(log); + put_type(log->type); + kfree(log); +} + +/*----------------------------------------------------------------- + * Persistent and core logs share a lot of their implementation. + * FIXME: need a reload method to be called from a resume + *---------------------------------------------------------------*/ +/* + * Magic for persistent mirrors: "MiRr" + */ +#define MIRROR_MAGIC 0x4D695272 + +/* + * The on-disk version of the metadata. + */ +#define MIRROR_DISK_VERSION 1 +#define LOG_OFFSET 2 + +struct log_header { + uint32_t magic; + + /* + * Simple, incrementing version. no backward + * compatibility. + */ + uint32_t version; + sector_t nr_regions; +}; + +struct log_c { + struct dm_target *ti; + int touched; + uint32_t region_size; + unsigned int region_count; + region_t sync_count; + + unsigned bitset_uint32_count; + uint32_t *clean_bits; + uint32_t *sync_bits; + uint32_t *recovering_bits; /* FIXME: this seems excessive */ + + int sync_search; + + /* Resync flag */ + enum sync { + DEFAULTSYNC, /* Synchronize if necessary */ + NOSYNC, /* Devices known to be already in sync */ + FORCESYNC, /* Force a sync to happen */ + } sync; + + /* + * Disk log fields + */ + struct dm_dev *log_dev; + struct log_header header; + + struct io_region header_location; + struct log_header *disk_header; + + struct io_region bits_location; + uint32_t *disk_bits; +}; + +/* + * The touched member needs to be updated every time we access + * one of the bitsets. + */ +static inline int log_test_bit(uint32_t *bs, unsigned bit) +{ + return test_bit(bit, (unsigned long *) bs) ? 1 : 0; +} + +static inline void log_set_bit(struct log_c *l, + uint32_t *bs, unsigned bit) +{ + set_bit(bit, (unsigned long *) bs); + l->touched = 1; +} + +static inline void log_clear_bit(struct log_c *l, + uint32_t *bs, unsigned bit) +{ + clear_bit(bit, (unsigned long *) bs); + l->touched = 1; +} + +/*---------------------------------------------------------------- + * Header IO + *--------------------------------------------------------------*/ +static void header_to_disk(struct log_header *core, struct log_header *disk) +{ + disk->magic = cpu_to_le32(core->magic); + disk->version = cpu_to_le32(core->version); + disk->nr_regions = cpu_to_le64(core->nr_regions); +} + +static void header_from_disk(struct log_header *core, struct log_header *disk) +{ + core->magic = le32_to_cpu(disk->magic); + core->version = le32_to_cpu(disk->version); + core->nr_regions = le64_to_cpu(disk->nr_regions); +} + +static int read_header(struct log_c *log) +{ + int r; + unsigned long ebits; + + r = dm_io_sync_vm(1, &log->header_location, READ, + log->disk_header, &ebits); + if (r) + return r; + + header_from_disk(&log->header, log->disk_header); + + /* New log required? */ + if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) { + log->header.magic = MIRROR_MAGIC; + log->header.version = MIRROR_DISK_VERSION; + log->header.nr_regions = 0; + } + + if (log->header.version != MIRROR_DISK_VERSION) { + DMWARN("incompatible disk log version"); + return -EINVAL; + } + + return 0; +} + +static inline int write_header(struct log_c *log) +{ + unsigned long ebits; + + header_to_disk(&log->header, log->disk_header); + return dm_io_sync_vm(1, &log->header_location, WRITE, + log->disk_header, &ebits); +} + +/*---------------------------------------------------------------- + * Bits IO + *--------------------------------------------------------------*/ +static inline void bits_to_core(uint32_t *core, uint32_t *disk, unsigned count) +{ + unsigned i; + + for (i = 0; i < count; i++) + core[i] = le32_to_cpu(disk[i]); +} + +static inline void bits_to_disk(uint32_t *core, uint32_t *disk, unsigned count) +{ + unsigned i; + + /* copy across the clean/dirty bitset */ + for (i = 0; i < count; i++) + disk[i] = cpu_to_le32(core[i]); +} + +static int read_bits(struct log_c *log) +{ + int r; + unsigned long ebits; + + r = dm_io_sync_vm(1, &log->bits_location, READ, + log->disk_bits, &ebits); + if (r) + return r; + + bits_to_core(log->clean_bits, log->disk_bits, + log->bitset_uint32_count); + return 0; +} + +static int write_bits(struct log_c *log) +{ + unsigned long ebits; + bits_to_disk(log->clean_bits, log->disk_bits, + log->bitset_uint32_count); + return dm_io_sync_vm(1, &log->bits_location, WRITE, + log->disk_bits, &ebits); +} + +/*---------------------------------------------------------------- + * core log constructor/destructor + * + * argv contains region_size followed optionally by [no]sync + *--------------------------------------------------------------*/ +#define BYTE_SHIFT 3 +static int core_ctr(struct dirty_log *log, struct dm_target *ti, + unsigned int argc, char **argv) +{ + enum sync sync = DEFAULTSYNC; + + struct log_c *lc; + uint32_t region_size; + unsigned int region_count; + size_t bitset_size; + + if (argc < 1 || argc > 2) { + DMWARN("wrong number of arguments to mirror log"); + return -EINVAL; + } + + if (argc > 1) { + if (!strcmp(argv[1], "sync")) + sync = FORCESYNC; + else if (!strcmp(argv[1], "nosync")) + sync = NOSYNC; + else { + DMWARN("unrecognised sync argument to mirror log: %s", + argv[1]); + return -EINVAL; + } + } + + if (sscanf(argv[0], "%u", ®ion_size) != 1) { + DMWARN("invalid region size string"); + return -EINVAL; + } + + region_count = dm_sector_div_up(ti->len, region_size); + + lc = kmalloc(sizeof(*lc), GFP_KERNEL); + if (!lc) { + DMWARN("couldn't allocate core log"); + return -ENOMEM; + } + + lc->ti = ti; + lc->touched = 0; + lc->region_size = region_size; + lc->region_count = region_count; + lc->sync = sync; + + /* + * Work out how many words we need to hold the bitset. + */ + bitset_size = dm_round_up(region_count, + sizeof(*lc->clean_bits) << BYTE_SHIFT); + bitset_size >>= BYTE_SHIFT; + + lc->bitset_uint32_count = bitset_size / 4; + lc->clean_bits = vmalloc(bitset_size); + if (!lc->clean_bits) { + DMWARN("couldn't allocate clean bitset"); + kfree(lc); + return -ENOMEM; + } + memset(lc->clean_bits, -1, bitset_size); + + lc->sync_bits = vmalloc(bitset_size); + if (!lc->sync_bits) { + DMWARN("couldn't allocate sync bitset"); + vfree(lc->clean_bits); + kfree(lc); + return -ENOMEM; + } + memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size); + lc->sync_count = (sync == NOSYNC) ? region_count : 0; + + lc->recovering_bits = vmalloc(bitset_size); + if (!lc->recovering_bits) { + DMWARN("couldn't allocate sync bitset"); + vfree(lc->sync_bits); + vfree(lc->clean_bits); + kfree(lc); + return -ENOMEM; + } + memset(lc->recovering_bits, 0, bitset_size); + lc->sync_search = 0; + log->context = lc; + return 0; +} + +static void core_dtr(struct dirty_log *log) +{ + struct log_c *lc = (struct log_c *) log->context; + vfree(lc->clean_bits); + vfree(lc->sync_bits); + vfree(lc->recovering_bits); + kfree(lc); +} + +/*---------------------------------------------------------------- + * disk log constructor/destructor + * + * argv contains log_device region_size followed optionally by [no]sync + *--------------------------------------------------------------*/ +static int disk_ctr(struct dirty_log *log, struct dm_target *ti, + unsigned int argc, char **argv) +{ + int r; + size_t size; + struct log_c *lc; + struct dm_dev *dev; + + if (argc < 2 || argc > 3) { + DMWARN("wrong number of arguments to disk mirror log"); + return -EINVAL; + } + + r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */, + FMODE_READ | FMODE_WRITE, &dev); + if (r) + return r; + + r = core_ctr(log, ti, argc - 1, argv + 1); + if (r) { + dm_put_device(ti, dev); + return r; + } + + lc = (struct log_c *) log->context; + lc->log_dev = dev; + + /* setup the disk header fields */ + lc->header_location.bdev = lc->log_dev->bdev; + lc->header_location.sector = 0; + lc->header_location.count = 1; + + /* + * We can't read less than this amount, even though we'll + * not be using most of this space. + */ + lc->disk_header = vmalloc(1 << SECTOR_SHIFT); + if (!lc->disk_header) + goto bad; + + /* setup the disk bitset fields */ + lc->bits_location.bdev = lc->log_dev->bdev; + lc->bits_location.sector = LOG_OFFSET; + + size = dm_round_up(lc->bitset_uint32_count * sizeof(uint32_t), + 1 << SECTOR_SHIFT); + lc->bits_location.count = size >> SECTOR_SHIFT; + lc->disk_bits = vmalloc(size); + if (!lc->disk_bits) { + vfree(lc->disk_header); + goto bad; + } + return 0; + + bad: + dm_put_device(ti, lc->log_dev); + core_dtr(log); + return -ENOMEM; +} + +static void disk_dtr(struct dirty_log *log) +{ + struct log_c *lc = (struct log_c *) log->context; + dm_put_device(lc->ti, lc->log_dev); + vfree(lc->disk_header); + vfree(lc->disk_bits); + core_dtr(log); +} + +static int count_bits32(uint32_t *addr, unsigned size) +{ + int count = 0, i; + + for (i = 0; i < size; i++) { + count += hweight32(*(addr+i)); + } + return count; +} + +static int disk_resume(struct dirty_log *log) +{ + int r; + unsigned i; + struct log_c *lc = (struct log_c *) log->context; + size_t size = lc->bitset_uint32_count * sizeof(uint32_t); + + /* read the disk header */ + r = read_header(lc); + if (r) + return r; + + /* read the bits */ + r = read_bits(lc); + if (r) + return r; + + /* set or clear any new bits */ + if (lc->sync == NOSYNC) + for (i = lc->header.nr_regions; i < lc->region_count; i++) + /* FIXME: amazingly inefficient */ + log_set_bit(lc, lc->clean_bits, i); + else + for (i = lc->header.nr_regions; i < lc->region_count; i++) + /* FIXME: amazingly inefficient */ + log_clear_bit(lc, lc->clean_bits, i); + + /* copy clean across to sync */ + memcpy(lc->sync_bits, lc->clean_bits, size); + lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count); + + /* write the bits */ + r = write_bits(lc); + if (r) + return r; + + /* set the correct number of regions in the header */ + lc->header.nr_regions = lc->region_count; + + /* write the new header */ + return write_header(lc); +} + +static uint32_t core_get_region_size(struct dirty_log *log) +{ + struct log_c *lc = (struct log_c *) log->context; + return lc->region_size; +} + +static int core_is_clean(struct dirty_log *log, region_t region) +{ + struct log_c *lc = (struct log_c *) log->context; + return log_test_bit(lc->clean_bits, region); +} + +static int core_in_sync(struct dirty_log *log, region_t region, int block) +{ + struct log_c *lc = (struct log_c *) log->context; + return log_test_bit(lc->sync_bits, region); +} + +static int core_flush(struct dirty_log *log) +{ + /* no op */ + return 0; +} + +static int disk_flush(struct dirty_log *log) +{ + int r; + struct log_c *lc = (struct log_c *) log->context; + + /* only write if the log has changed */ + if (!lc->touched) + return 0; + + r = write_bits(lc); + if (!r) + lc->touched = 0; + + return r; +} + +static void core_mark_region(struct dirty_log *log, region_t region) +{ + struct log_c *lc = (struct log_c *) log->context; + log_clear_bit(lc, lc->clean_bits, region); +} + +static void core_clear_region(struct dirty_log *log, region_t region) +{ + struct log_c *lc = (struct log_c *) log->context; + log_set_bit(lc, lc->clean_bits, region); +} + +static int core_get_resync_work(struct dirty_log *log, region_t *region) +{ + struct log_c *lc = (struct log_c *) log->context; + + if (lc->sync_search >= lc->region_count) + return 0; + + do { + *region = find_next_zero_bit((unsigned long *) lc->sync_bits, + lc->region_count, + lc->sync_search); + lc->sync_search = *region + 1; + + if (*region == lc->region_count) + return 0; + + } while (log_test_bit(lc->recovering_bits, *region)); + + log_set_bit(lc, lc->recovering_bits, *region); + return 1; +} + +static void core_complete_resync_work(struct dirty_log *log, region_t region, + int success) +{ + struct log_c *lc = (struct log_c *) log->context; + + log_clear_bit(lc, lc->recovering_bits, region); + if (success) { + log_set_bit(lc, lc->sync_bits, region); + lc->sync_count++; + } +} + +static region_t core_get_sync_count(struct dirty_log *log) +{ + struct log_c *lc = (struct log_c *) log->context; + + return lc->sync_count; +} + +#define DMEMIT_SYNC \ + if (lc->sync != DEFAULTSYNC) \ + DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "") + +static int core_status(struct dirty_log *log, status_type_t status, + char *result, unsigned int maxlen) +{ + int sz = 0; + struct log_c *lc = log->context; + + switch(status) { + case STATUSTYPE_INFO: + break; + + case STATUSTYPE_TABLE: + DMEMIT("%s %u %u ", log->type->name, + lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size); + DMEMIT_SYNC; + } + + return sz; +} + +static int disk_status(struct dirty_log *log, status_type_t status, + char *result, unsigned int maxlen) +{ + int sz = 0; + char buffer[16]; + struct log_c *lc = log->context; + + switch(status) { + case STATUSTYPE_INFO: + break; + + case STATUSTYPE_TABLE: + format_dev_t(buffer, lc->log_dev->bdev->bd_dev); + DMEMIT("%s %u %s %u ", log->type->name, + lc->sync == DEFAULTSYNC ? 2 : 3, buffer, + lc->region_size); + DMEMIT_SYNC; + } + + return sz; +} + +static struct dirty_log_type _core_type = { + .name = "core", + .module = THIS_MODULE, + .ctr = core_ctr, + .dtr = core_dtr, + .get_region_size = core_get_region_size, + .is_clean = core_is_clean, + .in_sync = core_in_sync, + .flush = core_flush, + .mark_region = core_mark_region, + .clear_region = core_clear_region, + .get_resync_work = core_get_resync_work, + .complete_resync_work = core_complete_resync_work, + .get_sync_count = core_get_sync_count, + .status = core_status, +}; + +static struct dirty_log_type _disk_type = { + .name = "disk", + .module = THIS_MODULE, + .ctr = disk_ctr, + .dtr = disk_dtr, + .suspend = disk_flush, + .resume = disk_resume, + .get_region_size = core_get_region_size, + .is_clean = core_is_clean, + .in_sync = core_in_sync, + .flush = disk_flush, + .mark_region = core_mark_region, + .clear_region = core_clear_region, + .get_resync_work = core_get_resync_work, + .complete_resync_work = core_complete_resync_work, + .get_sync_count = core_get_sync_count, + .status = disk_status, +}; + +int __init dm_dirty_log_init(void) +{ + int r; + + r = dm_register_dirty_log_type(&_core_type); + if (r) + DMWARN("couldn't register core log"); + + r = dm_register_dirty_log_type(&_disk_type); + if (r) { + DMWARN("couldn't register disk type"); + dm_unregister_dirty_log_type(&_core_type); + } + + return r; +} + +void dm_dirty_log_exit(void) +{ + dm_unregister_dirty_log_type(&_disk_type); + dm_unregister_dirty_log_type(&_core_type); +} + +EXPORT_SYMBOL(dm_register_dirty_log_type); +EXPORT_SYMBOL(dm_unregister_dirty_log_type); +EXPORT_SYMBOL(dm_create_dirty_log); +EXPORT_SYMBOL(dm_destroy_dirty_log); -- cgit v1.2.3