kvm tools: Cleanup disk image code

This patch cleans up disk image in preparation for supporting other disk
format.

Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/tools/kvm/disk-image.c b/tools/kvm/disk-image.c
index 678000865b63e56fc81e4070e9e83bd9e16bf19c..9a830270c68370f4185fba404d6688ce6508b714 100644 (file)
--- a/tools/kvm/disk-image.c
+++ b/tools/kvm/disk-image.c
@@ -13,43 +13,22 @@
 #include <unistd.h>
 #include <fcntl.h>
 
-struct disk_image *disk_image__open(const char *filename)
+struct disk_image *disk_image__new(int fd, uint64_t size, struct disk_image_operations *ops)
 {
        struct disk_image *self;
-       struct stat st;
 
        self            = malloc(sizeof *self);
        if (!self)
                return NULL;
 
-       self->fd        = open(filename, O_RDWR);
-       if (self->fd < 0)
-               goto failed_free;
-
-       if (fstat(self->fd, &st) < 0)
-               goto failed_close_fd;
-
-       self->size      = st.st_size;
+       self->fd        = fd;
+       self->size      = size;
+       self->ops       = ops;
 
        return self;
-
-failed_close_fd:
-       close(self->fd);
-failed_free:
-       free(self);
-
-       return NULL;
 }
 
-void disk_image__close(struct disk_image *self)
-{
-       if (close(self->fd) < 0)
-               warning("close() failed");
-
-       free(self);
-}
-
-int disk_image__read_sector(struct disk_image *self, uint64_t sector, void *dst, uint32_t dst_len)
+static int raw_image__read_sector(struct disk_image *self, uint64_t sector, void *dst, uint32_t dst_len)
 {
        uint64_t offset = sector << SECTOR_SHIFT;
 
@@ -65,7 +44,7 @@ int disk_image__read_sector(struct disk_image *self, uint64_t sector, void *dst,
        return 0;
 }
 
-int disk_image__write_sector(struct disk_image *self, uint64_t sector, void *src, uint32_t src_len)
+static int raw_image__write_sector(struct disk_image *self, uint64_t sector, void *src, uint32_t src_len)
 {
        uint64_t offset = sector << SECTOR_SHIFT;
 
@@ -80,3 +59,48 @@ int disk_image__write_sector(struct disk_image *self, uint64_t sector, void *src
 
        return 0;
 }
+
+static struct disk_image_operations raw_image_ops = {
+       .read_sector            = raw_image__read_sector,
+       .write_sector           = raw_image__write_sector,
+};
+
+static struct disk_image *raw_image__probe(int fd)
+{
+       struct stat st;
+
+       if (fstat(fd, &st) < 0)
+               return NULL;
+
+       return disk_image__new(fd, st.st_size, &raw_image_ops);
+}
+
+struct disk_image *disk_image__open(const char *filename)
+{
+       struct disk_image *self;
+       int fd;
+
+       fd              = open(filename, O_RDWR);
+       if (fd < 0)
+               return NULL;
+
+       self = raw_image__probe(fd);
+       if (self)
+               return self;
+
+       if (close(self->fd) < 0)
+               warning("close() failed");
+
+       return NULL;
+}
+
+void disk_image__close(struct disk_image *self)
+{
+       if (self->ops->close)
+               self->ops->close(self);
+
+       if (close(self->fd) < 0)
+               warning("close() failed");
+
+       free(self);
+}

diff --git a/tools/kvm/include/kvm/disk-image.h b/tools/kvm/include/kvm/disk-image.h
index 0599fc7670e1acae1c2652e4be9bf7a4a8493238..df0a15da92c428a466798ba52ff23da44f0b8db0 100644 (file)
--- a/tools/kvm/include/kvm/disk-image.h
+++ b/tools/kvm/include/kvm/disk-image.h
@@ -6,14 +6,33 @@
 #define SECTOR_SHIFT           9
 #define SECTOR_SIZE            (1UL << SECTOR_SHIFT)
 
+struct disk_image;
+
+struct disk_image_operations {
+       int (*read_sector)(struct disk_image *self, uint64_t sector, void *dst, uint32_t dst_len);
+       int (*write_sector)(struct disk_image *self, uint64_t sector, void *src, uint32_t src_len);
+       void (*close)(struct disk_image *self);
+};
+
 struct disk_image {
-       int             fd;
-       uint64_t        size;
+       int                             fd;
+       uint64_t                        size;
+       struct disk_image_operations    *ops;
+       void                            *priv;
 };
 
 struct disk_image *disk_image__open(const char *filename);
+struct disk_image *disk_image__new(int fd, uint64_t size, struct disk_image_operations *ops);
 void disk_image__close(struct disk_image *self);
-int disk_image__read_sector(struct disk_image *self, uint64_t sector, void *dst, uint32_t dst_len);
-int disk_image__write_sector(struct disk_image *self, uint64_t sector, void *src, uint32_t src_len);
+
+static inline int disk_image__read_sector(struct disk_image *self, uint64_t sector, void *dst, uint32_t dst_len)
+{
+       return self->ops->read_sector(self, sector, dst, dst_len);
+}
+
+static inline int disk_image__write_sector(struct disk_image *self, uint64_t sector, void *src, uint32_t src_len)
+{
+       return self->ops->write_sector(self, sector, src, src_len);
+}
 
 #endif /* KVM__DISK_IMAGE_H */