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!
diff --git a/drivers/md/dm-log.c b/drivers/md/dm-log.c
new file mode 100644
index 0000000..e110655
--- /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 <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+
+#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);