![Stefan Bader](/assets/img/avatar_default.png)
This is a fix to the device-mapper-log-bitset-fix-endian patch that switched to ext2_* versions of the set and clear bit functions. The find_next_zero_bit function also has to be the ext2 one. Otherwise the mirror target tries to recover non-existent regions beyond the end of device. Signed-off-by: Stefan Bader <shbader@de.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
690 lines
15 KiB
C
690 lines
15 KiB
C
/*
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* Copyright (C) 2003 Sistina Software
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*
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* This file is released under the LGPL.
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*/
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/vmalloc.h>
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#include "dm-log.h"
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#include "dm-io.h"
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static LIST_HEAD(_log_types);
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static DEFINE_SPINLOCK(_lock);
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int dm_register_dirty_log_type(struct dirty_log_type *type)
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{
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spin_lock(&_lock);
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type->use_count = 0;
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list_add(&type->list, &_log_types);
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spin_unlock(&_lock);
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return 0;
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}
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int dm_unregister_dirty_log_type(struct dirty_log_type *type)
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{
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spin_lock(&_lock);
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if (type->use_count)
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DMWARN("Attempt to unregister a log type that is still in use");
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else
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list_del(&type->list);
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spin_unlock(&_lock);
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return 0;
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}
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static struct dirty_log_type *get_type(const char *type_name)
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{
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struct dirty_log_type *type;
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spin_lock(&_lock);
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list_for_each_entry (type, &_log_types, list)
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if (!strcmp(type_name, type->name)) {
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if (!type->use_count && !try_module_get(type->module)){
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spin_unlock(&_lock);
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return NULL;
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}
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type->use_count++;
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spin_unlock(&_lock);
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return type;
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}
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spin_unlock(&_lock);
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return NULL;
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}
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static void put_type(struct dirty_log_type *type)
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{
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spin_lock(&_lock);
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if (!--type->use_count)
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module_put(type->module);
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spin_unlock(&_lock);
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}
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struct dirty_log *dm_create_dirty_log(const char *type_name, struct dm_target *ti,
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unsigned int argc, char **argv)
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{
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struct dirty_log_type *type;
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struct dirty_log *log;
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log = kmalloc(sizeof(*log), GFP_KERNEL);
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if (!log)
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return NULL;
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type = get_type(type_name);
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if (!type) {
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kfree(log);
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return NULL;
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}
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log->type = type;
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if (type->ctr(log, ti, argc, argv)) {
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kfree(log);
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put_type(type);
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return NULL;
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}
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return log;
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}
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void dm_destroy_dirty_log(struct dirty_log *log)
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{
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log->type->dtr(log);
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put_type(log->type);
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kfree(log);
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}
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/*-----------------------------------------------------------------
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* Persistent and core logs share a lot of their implementation.
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* FIXME: need a reload method to be called from a resume
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*---------------------------------------------------------------*/
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/*
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* Magic for persistent mirrors: "MiRr"
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*/
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#define MIRROR_MAGIC 0x4D695272
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/*
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* The on-disk version of the metadata.
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*/
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#define MIRROR_DISK_VERSION 2
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#define LOG_OFFSET 2
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struct log_header {
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uint32_t magic;
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/*
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* Simple, incrementing version. no backward
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* compatibility.
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*/
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uint32_t version;
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sector_t nr_regions;
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};
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struct log_c {
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struct dm_target *ti;
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int touched;
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uint32_t region_size;
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unsigned int region_count;
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region_t sync_count;
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unsigned bitset_uint32_count;
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uint32_t *clean_bits;
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uint32_t *sync_bits;
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uint32_t *recovering_bits; /* FIXME: this seems excessive */
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int sync_search;
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/* Resync flag */
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enum sync {
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DEFAULTSYNC, /* Synchronize if necessary */
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NOSYNC, /* Devices known to be already in sync */
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FORCESYNC, /* Force a sync to happen */
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} sync;
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/*
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* Disk log fields
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*/
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struct dm_dev *log_dev;
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struct log_header header;
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struct io_region header_location;
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struct log_header *disk_header;
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struct io_region bits_location;
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};
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/*
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* The touched member needs to be updated every time we access
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* one of the bitsets.
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*/
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static inline int log_test_bit(uint32_t *bs, unsigned bit)
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{
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return ext2_test_bit(bit, (unsigned long *) bs) ? 1 : 0;
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}
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static inline void log_set_bit(struct log_c *l,
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uint32_t *bs, unsigned bit)
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{
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ext2_set_bit(bit, (unsigned long *) bs);
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l->touched = 1;
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}
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static inline void log_clear_bit(struct log_c *l,
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uint32_t *bs, unsigned bit)
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{
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ext2_clear_bit(bit, (unsigned long *) bs);
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l->touched = 1;
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}
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/*----------------------------------------------------------------
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* Header IO
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*--------------------------------------------------------------*/
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static void header_to_disk(struct log_header *core, struct log_header *disk)
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{
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disk->magic = cpu_to_le32(core->magic);
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disk->version = cpu_to_le32(core->version);
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disk->nr_regions = cpu_to_le64(core->nr_regions);
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}
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static void header_from_disk(struct log_header *core, struct log_header *disk)
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{
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core->magic = le32_to_cpu(disk->magic);
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core->version = le32_to_cpu(disk->version);
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core->nr_regions = le64_to_cpu(disk->nr_regions);
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}
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static int read_header(struct log_c *log)
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{
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int r;
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unsigned long ebits;
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r = dm_io_sync_vm(1, &log->header_location, READ,
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log->disk_header, &ebits);
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if (r)
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return r;
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header_from_disk(&log->header, log->disk_header);
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/* New log required? */
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if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
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log->header.magic = MIRROR_MAGIC;
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log->header.version = MIRROR_DISK_VERSION;
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log->header.nr_regions = 0;
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}
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#ifdef __LITTLE_ENDIAN
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if (log->header.version == 1)
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log->header.version = 2;
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#endif
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if (log->header.version != MIRROR_DISK_VERSION) {
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DMWARN("incompatible disk log version");
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return -EINVAL;
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}
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return 0;
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}
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static inline int write_header(struct log_c *log)
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{
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unsigned long ebits;
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header_to_disk(&log->header, log->disk_header);
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return dm_io_sync_vm(1, &log->header_location, WRITE,
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log->disk_header, &ebits);
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}
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/*----------------------------------------------------------------
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* Bits IO
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*--------------------------------------------------------------*/
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static int read_bits(struct log_c *log)
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{
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int r;
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unsigned long ebits;
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r = dm_io_sync_vm(1, &log->bits_location, READ,
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log->clean_bits, &ebits);
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if (r)
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return r;
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return 0;
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}
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static int write_bits(struct log_c *log)
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{
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unsigned long ebits;
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return dm_io_sync_vm(1, &log->bits_location, WRITE,
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log->clean_bits, &ebits);
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}
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/*----------------------------------------------------------------
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* core log constructor/destructor
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*
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* argv contains region_size followed optionally by [no]sync
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*--------------------------------------------------------------*/
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#define BYTE_SHIFT 3
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static int core_ctr(struct dirty_log *log, struct dm_target *ti,
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unsigned int argc, char **argv)
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{
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enum sync sync = DEFAULTSYNC;
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struct log_c *lc;
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uint32_t region_size;
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unsigned int region_count;
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size_t bitset_size;
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if (argc < 1 || argc > 2) {
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DMWARN("wrong number of arguments to mirror log");
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return -EINVAL;
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}
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if (argc > 1) {
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if (!strcmp(argv[1], "sync"))
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sync = FORCESYNC;
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else if (!strcmp(argv[1], "nosync"))
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sync = NOSYNC;
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else {
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DMWARN("unrecognised sync argument to mirror log: %s",
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argv[1]);
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return -EINVAL;
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}
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}
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if (sscanf(argv[0], "%u", ®ion_size) != 1) {
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DMWARN("invalid region size string");
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return -EINVAL;
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}
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region_count = dm_sector_div_up(ti->len, region_size);
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lc = kmalloc(sizeof(*lc), GFP_KERNEL);
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if (!lc) {
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DMWARN("couldn't allocate core log");
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return -ENOMEM;
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}
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lc->ti = ti;
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lc->touched = 0;
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lc->region_size = region_size;
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lc->region_count = region_count;
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lc->sync = sync;
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/*
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* Work out how many "unsigned long"s we need to hold the bitset.
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*/
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bitset_size = dm_round_up(region_count,
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sizeof(unsigned long) << BYTE_SHIFT);
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bitset_size >>= BYTE_SHIFT;
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lc->bitset_uint32_count = bitset_size / 4;
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lc->clean_bits = vmalloc(bitset_size);
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if (!lc->clean_bits) {
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DMWARN("couldn't allocate clean bitset");
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kfree(lc);
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return -ENOMEM;
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}
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memset(lc->clean_bits, -1, bitset_size);
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lc->sync_bits = vmalloc(bitset_size);
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if (!lc->sync_bits) {
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DMWARN("couldn't allocate sync bitset");
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vfree(lc->clean_bits);
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kfree(lc);
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return -ENOMEM;
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}
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memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
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lc->sync_count = (sync == NOSYNC) ? region_count : 0;
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lc->recovering_bits = vmalloc(bitset_size);
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if (!lc->recovering_bits) {
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DMWARN("couldn't allocate sync bitset");
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vfree(lc->sync_bits);
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vfree(lc->clean_bits);
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kfree(lc);
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return -ENOMEM;
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}
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memset(lc->recovering_bits, 0, bitset_size);
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lc->sync_search = 0;
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log->context = lc;
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return 0;
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}
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static void core_dtr(struct dirty_log *log)
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{
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struct log_c *lc = (struct log_c *) log->context;
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vfree(lc->clean_bits);
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vfree(lc->sync_bits);
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vfree(lc->recovering_bits);
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kfree(lc);
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}
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/*----------------------------------------------------------------
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* disk log constructor/destructor
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*
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* argv contains log_device region_size followed optionally by [no]sync
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*--------------------------------------------------------------*/
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static int disk_ctr(struct dirty_log *log, struct dm_target *ti,
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unsigned int argc, char **argv)
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{
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int r;
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size_t size;
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struct log_c *lc;
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struct dm_dev *dev;
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if (argc < 2 || argc > 3) {
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DMWARN("wrong number of arguments to disk mirror log");
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return -EINVAL;
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}
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r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */,
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FMODE_READ | FMODE_WRITE, &dev);
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if (r)
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return r;
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r = core_ctr(log, ti, argc - 1, argv + 1);
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if (r) {
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dm_put_device(ti, dev);
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return r;
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}
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lc = (struct log_c *) log->context;
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lc->log_dev = dev;
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/* setup the disk header fields */
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lc->header_location.bdev = lc->log_dev->bdev;
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lc->header_location.sector = 0;
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lc->header_location.count = 1;
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/*
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* We can't read less than this amount, even though we'll
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* not be using most of this space.
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*/
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lc->disk_header = vmalloc(1 << SECTOR_SHIFT);
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if (!lc->disk_header)
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goto bad;
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/* setup the disk bitset fields */
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lc->bits_location.bdev = lc->log_dev->bdev;
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lc->bits_location.sector = LOG_OFFSET;
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size = dm_round_up(lc->bitset_uint32_count * sizeof(uint32_t),
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1 << SECTOR_SHIFT);
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lc->bits_location.count = size >> SECTOR_SHIFT;
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return 0;
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bad:
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dm_put_device(ti, lc->log_dev);
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core_dtr(log);
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return -ENOMEM;
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}
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static void disk_dtr(struct dirty_log *log)
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{
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struct log_c *lc = (struct log_c *) log->context;
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dm_put_device(lc->ti, lc->log_dev);
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vfree(lc->disk_header);
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core_dtr(log);
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}
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static int count_bits32(uint32_t *addr, unsigned size)
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{
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int count = 0, i;
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for (i = 0; i < size; i++) {
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count += hweight32(*(addr+i));
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}
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return count;
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}
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static int disk_resume(struct dirty_log *log)
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{
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int r;
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unsigned i;
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struct log_c *lc = (struct log_c *) log->context;
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size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
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/* read the disk header */
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r = read_header(lc);
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if (r)
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return r;
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/* read the bits */
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r = read_bits(lc);
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if (r)
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return r;
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/* set or clear any new bits */
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if (lc->sync == NOSYNC)
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for (i = lc->header.nr_regions; i < lc->region_count; i++)
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/* FIXME: amazingly inefficient */
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log_set_bit(lc, lc->clean_bits, i);
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else
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for (i = lc->header.nr_regions; i < lc->region_count; i++)
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/* FIXME: amazingly inefficient */
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log_clear_bit(lc, lc->clean_bits, i);
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/* copy clean across to sync */
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memcpy(lc->sync_bits, lc->clean_bits, size);
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lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
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/* write the bits */
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r = write_bits(lc);
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if (r)
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return r;
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/* set the correct number of regions in the header */
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lc->header.nr_regions = lc->region_count;
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/* write the new header */
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return write_header(lc);
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}
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static uint32_t core_get_region_size(struct dirty_log *log)
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{
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struct log_c *lc = (struct log_c *) log->context;
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return lc->region_size;
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}
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static int core_is_clean(struct dirty_log *log, region_t region)
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{
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struct log_c *lc = (struct log_c *) log->context;
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return log_test_bit(lc->clean_bits, region);
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}
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static int core_in_sync(struct dirty_log *log, region_t region, int block)
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{
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struct log_c *lc = (struct log_c *) log->context;
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return log_test_bit(lc->sync_bits, region);
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}
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static int core_flush(struct dirty_log *log)
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{
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/* no op */
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return 0;
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}
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static int disk_flush(struct dirty_log *log)
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{
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int r;
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struct log_c *lc = (struct log_c *) log->context;
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/* only write if the log has changed */
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if (!lc->touched)
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return 0;
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r = write_bits(lc);
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if (!r)
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lc->touched = 0;
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return r;
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}
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static void core_mark_region(struct dirty_log *log, region_t region)
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{
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struct log_c *lc = (struct log_c *) log->context;
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log_clear_bit(lc, lc->clean_bits, region);
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}
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static void core_clear_region(struct dirty_log *log, region_t region)
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{
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struct log_c *lc = (struct log_c *) log->context;
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log_set_bit(lc, lc->clean_bits, region);
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}
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static int core_get_resync_work(struct dirty_log *log, region_t *region)
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{
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struct log_c *lc = (struct log_c *) log->context;
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if (lc->sync_search >= lc->region_count)
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return 0;
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do {
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*region = ext2_find_next_zero_bit(
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(unsigned long *) lc->sync_bits,
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lc->region_count,
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lc->sync_search);
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lc->sync_search = *region + 1;
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if (*region >= lc->region_count)
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return 0;
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|
|
|
} 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);
|