96 lines
2.2 KiB
C
96 lines
2.2 KiB
C
#include <libcbd.h>
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#include <libdevmapper.h>
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#include <cbdutil.h>
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static uint64_t
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device_logical_sectors(const char* dev)
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{
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int fd;
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uint8_t buf[SECTOR_SIZE];
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struct cbd_header header;
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uint64_t lblk_total;
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fd = open(dev, O_RDONLY);
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if (fd < 0) {
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error("Cannot open device\n");
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}
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if (read(fd, buf, sizeof(buf)) != sizeof(buf)) {
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error("Cannot read device\n");
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}
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close(fd);
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cbd_header_get(buf, &header);
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if (memcmp(header.magic, CBD_MAGIC, sizeof(header.magic)) != 0) {
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error("Bad magic\n");
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}
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lblk_total = header.params.lblk_per_zone * header.params.nr_zones;
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return lblk_total >> (header.params.lblk_shift + header.params.pblk_shift);
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}
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int
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cbd_open(const char* dev,
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const char* name,
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uint64_t cache_pages, bool sync)
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{
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int ret;
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struct stat st;
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uint64_t nr_logical_sectors;
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char optbuf[80];
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char params[256];
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struct dm_task* dmt;
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uint32_t cookie = 0;
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ret = stat(dev, &st);
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if (ret) {
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error("Failed to stat device\n");
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}
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if (!S_ISBLK(st.st_mode)) {
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error("Not a block device\n");
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}
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nr_logical_sectors = device_logical_sectors(dev);
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strcpy(params, dev);
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if (cache_pages) {
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sprintf(optbuf, " cache_pages=%lu", (unsigned long)cache_pages);
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strcat(params, optbuf);
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}
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if (sync) {
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strcat(params, " sync");
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}
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dmt = dm_task_create(DM_DEVICE_CREATE);
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if (!dmt) {
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error("dm_task_create failed\n");
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}
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ret = dm_task_set_name(dmt, name);
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if (ret == 0) {
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error("dm_task_set_name failed\n");
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}
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printf("%s: start_sector=0 num_sectors=%lu\n", __func__,
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(unsigned long)nr_logical_sectors);
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ret = dm_task_add_target(dmt,
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0,
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nr_logical_sectors,
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"compress",
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params);
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if (ret == 0) {
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error("dm_task_add_target failed\n");
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}
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ret = dm_task_set_cookie(dmt, &cookie, 0);
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if (ret == 0) {
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error("dm_task_set_cookie failed\n");
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}
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ret = dm_task_run(dmt);
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if (ret == 0) {
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error("dm_task_run failed\n");
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}
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dm_udev_wait(cookie);
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dm_task_destroy(dmt);
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return 0;
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}
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