xref: /kvmtool/disk/core.c (revision fda63751b248c842674cebe7dbc110eb2b4f356a)
19f532d00SPekka Enberg #include "kvm/disk-image.h"
286835cedSPrasad Joshi #include "kvm/qcow.h"
39f532d00SPekka Enberg 
47d22135fSAsias He struct disk_image *disk_image__new(int fd, u64 size, struct disk_image_operations *ops, int use_mmap)
59f532d00SPekka Enberg {
643835ac9SSasha Levin 	struct disk_image *disk;
79f532d00SPekka Enberg 
843835ac9SSasha Levin 	disk		= malloc(sizeof *disk);
943835ac9SSasha Levin 	if (!disk)
10fffb37a9SPekka Enberg 		return NULL;
119f532d00SPekka Enberg 
1243835ac9SSasha Levin 	disk->fd	= fd;
1343835ac9SSasha Levin 	disk->size	= size;
1443835ac9SSasha Levin 	disk->ops	= ops;
15f4ff38dfSPrasad Joshi 
167d22135fSAsias He 	if (use_mmap == DISK_IMAGE_MMAP) {
177d22135fSAsias He 		/*
187d22135fSAsias He 		 * The write to disk image will be discarded
197d22135fSAsias He 		 */
2037c34ca8SSasha Levin 		disk->priv = mmap(NULL, size, PROT_RW, MAP_PRIVATE | MAP_NORESERVE, fd, 0);
2143835ac9SSasha Levin 		if (disk->priv == MAP_FAILED)
229ac38fe1SSasha Levin 			die("mmap() failed");
237d22135fSAsias He 	}
247d22135fSAsias He 
2543835ac9SSasha Levin 	return disk;
269f532d00SPekka Enberg }
279f532d00SPekka Enberg 
289ac38fe1SSasha Levin struct disk_image *disk_image__open(const char *filename, bool readonly)
29499f3bedSPekka Enberg {
3043835ac9SSasha Levin 	struct disk_image *disk;
316ec60cfdSPekka Enberg 	struct stat st;
32499f3bedSPekka Enberg 	int fd;
33499f3bedSPekka Enberg 
346ec60cfdSPekka Enberg 	if (stat(filename, &st) < 0)
356ec60cfdSPekka Enberg 		return NULL;
366ec60cfdSPekka Enberg 
37441767feSAsias He 	/* blk device ?*/
38441767feSAsias He 	disk		= blkdev__probe(filename, &st);
39441767feSAsias He 	if (disk)
40441767feSAsias He 		return disk;
416ec60cfdSPekka Enberg 
429ac38fe1SSasha Levin 	fd		= open(filename, readonly ? O_RDONLY : O_RDWR);
43499f3bedSPekka Enberg 	if (fd < 0)
44499f3bedSPekka Enberg 		return NULL;
45499f3bedSPekka Enberg 
46441767feSAsias He 	/* qcow image ?*/
47f10860caSPekka Enberg 	disk		= qcow_probe(fd, readonly);
4843835ac9SSasha Levin 	if (disk)
4943835ac9SSasha Levin 		return disk;
5086835cedSPrasad Joshi 
51441767feSAsias He 	/* raw image ?*/
5243835ac9SSasha Levin 	disk		= raw_image__probe(fd, &st, readonly);
5343835ac9SSasha Levin 	if (disk)
5443835ac9SSasha Levin 		return disk;
55499f3bedSPekka Enberg 
56d6c58e5bSPrasad Joshi 	if (close(fd) < 0)
57499f3bedSPekka Enberg 		warning("close() failed");
58499f3bedSPekka Enberg 
59499f3bedSPekka Enberg 	return NULL;
60499f3bedSPekka Enberg }
61499f3bedSPekka Enberg 
62*fda63751SAsias He int disk_image__flush(struct disk_image *disk)
63*fda63751SAsias He {
64*fda63751SAsias He 	if (disk->ops->flush)
65*fda63751SAsias He 		return disk->ops->flush(disk);
66*fda63751SAsias He 
67*fda63751SAsias He 	return fsync(disk->fd);
68*fda63751SAsias He }
69*fda63751SAsias He 
7072133dd2SAsias He int disk_image__close(struct disk_image *disk)
71499f3bedSPekka Enberg {
7282d94c50SIngo Molnar 	/* If there was no disk image then there's nothing to do: */
7343835ac9SSasha Levin 	if (!disk)
7472133dd2SAsias He 		return 0;
7582d94c50SIngo Molnar 
7643835ac9SSasha Levin 	if (disk->ops->close)
7772133dd2SAsias He 		return disk->ops->close(disk);
78499f3bedSPekka Enberg 
7943835ac9SSasha Levin 	if (close(disk->fd) < 0)
80499f3bedSPekka Enberg 		warning("close() failed");
81499f3bedSPekka Enberg 
8243835ac9SSasha Levin 	free(disk);
8372133dd2SAsias He 
8472133dd2SAsias He 	return 0;
85499f3bedSPekka Enberg }
8670b0d7b0SSasha Levin 
8770b0d7b0SSasha Levin /* Fill iov with disk data, starting from sector 'sector'. Return amount of bytes read. */
88b8861977SAsias He ssize_t disk_image__read(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
8970b0d7b0SSasha Levin {
9070b0d7b0SSasha Levin 	u64 first_sector = sector;
9170b0d7b0SSasha Levin 
9270b0d7b0SSasha Levin 	if (disk->ops->read_sector_iov)
9370b0d7b0SSasha Levin 		return disk->ops->read_sector_iov(disk, sector, iov, iovcount);
9470b0d7b0SSasha Levin 
9570b0d7b0SSasha Levin 	while (iovcount--) {
9670b0d7b0SSasha Levin 		if (disk->ops->read_sector(disk, sector, iov->iov_base, iov->iov_len) < 0)
9770b0d7b0SSasha Levin 			return -1;
9870b0d7b0SSasha Levin 
9970b0d7b0SSasha Levin 		sector += iov->iov_len >> SECTOR_SHIFT;
10070b0d7b0SSasha Levin 		iov++;
10170b0d7b0SSasha Levin 	}
10270b0d7b0SSasha Levin 
10370b0d7b0SSasha Levin 	return (sector - first_sector) << SECTOR_SHIFT;
10470b0d7b0SSasha Levin }
10570b0d7b0SSasha Levin 
10670b0d7b0SSasha Levin /* Write iov to disk, starting from sector 'sector'. Return amount of bytes written. */
107b8861977SAsias He ssize_t disk_image__write(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
10870b0d7b0SSasha Levin {
10970b0d7b0SSasha Levin 	u64 first_sector = sector;
11070b0d7b0SSasha Levin 
11170b0d7b0SSasha Levin 	if (disk->ops->write_sector_iov)
11270b0d7b0SSasha Levin 		return disk->ops->write_sector_iov(disk, sector, iov, iovcount);
11370b0d7b0SSasha Levin 
11470b0d7b0SSasha Levin 	while (iovcount--) {
11570b0d7b0SSasha Levin 		if (disk->ops->write_sector(disk, sector, iov->iov_base, iov->iov_len) < 0)
11670b0d7b0SSasha Levin 			return -1;
11770b0d7b0SSasha Levin 
11870b0d7b0SSasha Levin 		sector += iov->iov_len >> SECTOR_SHIFT;
11970b0d7b0SSasha Levin 		iov++;
12070b0d7b0SSasha Levin 	}
12170b0d7b0SSasha Levin 
12270b0d7b0SSasha Levin 	return (sector - first_sector) << SECTOR_SHIFT;
12370b0d7b0SSasha Levin }
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