xref: /kvmtool/disk/core.c (revision 72133dd2d8ab6fbc651a5e3b65391f2bcd29c7d5)
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 
376ec60cfdSPekka Enberg 	if (S_ISBLK(st.st_mode))
386ec60cfdSPekka Enberg 		return blkdev__probe(filename, &st);
396ec60cfdSPekka Enberg 
409ac38fe1SSasha Levin 	fd		= open(filename, readonly ? O_RDONLY : O_RDWR);
41499f3bedSPekka Enberg 	if (fd < 0)
42499f3bedSPekka Enberg 		return NULL;
43499f3bedSPekka Enberg 
44f10860caSPekka Enberg 	disk = qcow_probe(fd, readonly);
4543835ac9SSasha Levin 	if (disk)
4643835ac9SSasha Levin 		return disk;
4786835cedSPrasad Joshi 
4843835ac9SSasha Levin 	disk = raw_image__probe(fd, &st, readonly);
4943835ac9SSasha Levin 	if (disk)
5043835ac9SSasha Levin 		return disk;
51499f3bedSPekka Enberg 
52d6c58e5bSPrasad Joshi 	if (close(fd) < 0)
53499f3bedSPekka Enberg 		warning("close() failed");
54499f3bedSPekka Enberg 
55499f3bedSPekka Enberg 	return NULL;
56499f3bedSPekka Enberg }
57499f3bedSPekka Enberg 
58*72133dd2SAsias He int disk_image__close(struct disk_image *disk)
59499f3bedSPekka Enberg {
6082d94c50SIngo Molnar 	/* If there was no disk image then there's nothing to do: */
6143835ac9SSasha Levin 	if (!disk)
62*72133dd2SAsias He 		return 0;
6382d94c50SIngo Molnar 
6443835ac9SSasha Levin 	if (disk->ops->close)
65*72133dd2SAsias He 		return disk->ops->close(disk);
66499f3bedSPekka Enberg 
6743835ac9SSasha Levin 	if (close(disk->fd) < 0)
68499f3bedSPekka Enberg 		warning("close() failed");
69499f3bedSPekka Enberg 
7043835ac9SSasha Levin 	free(disk);
71*72133dd2SAsias He 
72*72133dd2SAsias He 	return 0;
73499f3bedSPekka Enberg }
7470b0d7b0SSasha Levin 
7570b0d7b0SSasha Levin /* Fill iov with disk data, starting from sector 'sector'. Return amount of bytes read. */
76b8861977SAsias He ssize_t disk_image__read(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
7770b0d7b0SSasha Levin {
7870b0d7b0SSasha Levin 	u64 first_sector = sector;
7970b0d7b0SSasha Levin 
8070b0d7b0SSasha Levin 	if (disk->ops->read_sector_iov)
8170b0d7b0SSasha Levin 		return disk->ops->read_sector_iov(disk, sector, iov, iovcount);
8270b0d7b0SSasha Levin 
8370b0d7b0SSasha Levin 	while (iovcount--) {
8470b0d7b0SSasha Levin 		if (disk->ops->read_sector(disk, sector, iov->iov_base, iov->iov_len) < 0)
8570b0d7b0SSasha Levin 			return -1;
8670b0d7b0SSasha Levin 
8770b0d7b0SSasha Levin 		sector += iov->iov_len >> SECTOR_SHIFT;
8870b0d7b0SSasha Levin 		iov++;
8970b0d7b0SSasha Levin 	}
9070b0d7b0SSasha Levin 
9170b0d7b0SSasha Levin 	return (sector - first_sector) << SECTOR_SHIFT;
9270b0d7b0SSasha Levin }
9370b0d7b0SSasha Levin 
9470b0d7b0SSasha Levin /* Write iov to disk, starting from sector 'sector'. Return amount of bytes written. */
95b8861977SAsias He ssize_t disk_image__write(struct disk_image *disk, u64 sector, const struct iovec *iov, int iovcount)
9670b0d7b0SSasha Levin {
9770b0d7b0SSasha Levin 	u64 first_sector = sector;
9870b0d7b0SSasha Levin 
9970b0d7b0SSasha Levin 	if (disk->ops->write_sector_iov)
10070b0d7b0SSasha Levin 		return disk->ops->write_sector_iov(disk, sector, iov, iovcount);
10170b0d7b0SSasha Levin 
10270b0d7b0SSasha Levin 	while (iovcount--) {
10370b0d7b0SSasha Levin 		if (disk->ops->write_sector(disk, sector, iov->iov_base, iov->iov_len) < 0)
10470b0d7b0SSasha Levin 			return -1;
10570b0d7b0SSasha Levin 
10670b0d7b0SSasha Levin 		sector += iov->iov_len >> SECTOR_SHIFT;
10770b0d7b0SSasha Levin 		iov++;
10870b0d7b0SSasha Levin 	}
10970b0d7b0SSasha Levin 
11070b0d7b0SSasha Levin 	return (sector - first_sector) << SECTOR_SHIFT;
11170b0d7b0SSasha Levin }
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