disk/aio: Refactor AIO code
Move all AIO code to a separate file, disk/aio.c, to remove as much
#ifdefs as possible. Split the raw read/write disk ops into async and
sync, and choose which ones to use depending on CONFIG_HAS_AIO. Note that
we fix raw_image__close() which incorrectly checked CONFIG_HAS_VIRTIO
instead of CONFIG_HAS_AIO, and closed an unitialized disk->evt. A
subsequent commit will complete this refactoring by fixing use of the
'async' disk attribute.
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/Makefile b/Makefile
index 25f13a0..3862112 100644
--- a/Makefile
+++ b/Makefile
@@ -276,10 +276,12 @@
ifeq ($(call try-build,$(SOURCE_AIO),$(CFLAGS),$(LDFLAGS) -laio),y)
CFLAGS_DYNOPT += -DCONFIG_HAS_AIO
LIBS_DYNOPT += -laio
+ OBJS_DYNOPT += disk/aio.o
else
ifeq ($(call try-build,$(SOURCE_AIO),$(CFLAGS),$(LDFLAGS) -laio -static),y)
CFLAGS_STATOPT += -DCONFIG_HAS_AIO
LIBS_STATOPT += -laio
+ OBJS_STATOPT += disk/aio.o
else
NOTFOUND += aio
endif
diff --git a/disk/aio.c b/disk/aio.c
new file mode 100644
index 0000000..6afcffe
--- /dev/null
+++ b/disk/aio.c
@@ -0,0 +1,111 @@
+#include <libaio.h>
+#include <pthread.h>
+#include <sys/eventfd.h>
+
+#include "kvm/disk-image.h"
+#include "kvm/kvm.h"
+#include "linux/list.h"
+
+#define AIO_MAX 256
+
+static int aio_pwritev(io_context_t ctx, struct iocb *iocb, int fd,
+ const struct iovec *iov, int iovcnt, off_t offset,
+ int ev, void *param)
+{
+ struct iocb *ios[1] = { iocb };
+ int ret;
+
+ io_prep_pwritev(iocb, fd, iov, iovcnt, offset);
+ io_set_eventfd(iocb, ev);
+ iocb->data = param;
+
+restart:
+ ret = io_submit(ctx, 1, ios);
+ if (ret == -EAGAIN)
+ goto restart;
+ return ret;
+}
+
+static int aio_preadv(io_context_t ctx, struct iocb *iocb, int fd,
+ const struct iovec *iov, int iovcnt, off_t offset,
+ int ev, void *param)
+{
+ struct iocb *ios[1] = { iocb };
+ int ret;
+
+ io_prep_preadv(iocb, fd, iov, iovcnt, offset);
+ io_set_eventfd(iocb, ev);
+ iocb->data = param;
+
+restart:
+ ret = io_submit(ctx, 1, ios);
+ if (ret == -EAGAIN)
+ goto restart;
+ return ret;
+}
+
+ssize_t raw_image__read_async(struct disk_image *disk, u64 sector,
+ const struct iovec *iov, int iovcount,
+ void *param)
+{
+ u64 offset = sector << SECTOR_SHIFT;
+ struct iocb iocb;
+
+ return aio_preadv(disk->ctx, &iocb, disk->fd, iov, iovcount,
+ offset, disk->evt, param);
+}
+
+ssize_t raw_image__write_async(struct disk_image *disk, u64 sector,
+ const struct iovec *iov, int iovcount,
+ void *param)
+{
+ u64 offset = sector << SECTOR_SHIFT;
+ struct iocb iocb;
+
+ return aio_pwritev(disk->ctx, &iocb, disk->fd, iov, iovcount,
+ offset, disk->evt, param);
+}
+
+static void *disk_aio_thread(void *param)
+{
+ struct disk_image *disk = param;
+ struct io_event event[AIO_MAX];
+ struct timespec notime = {0};
+ int nr, i;
+ u64 dummy;
+
+ kvm__set_thread_name("disk-image-io");
+
+ while (read(disk->evt, &dummy, sizeof(dummy)) > 0) {
+ nr = io_getevents(disk->ctx, 1, ARRAY_SIZE(event), event, ¬ime);
+ for (i = 0; i < nr; i++)
+ disk->disk_req_cb(event[i].data, event[i].res);
+ }
+
+ return NULL;
+}
+
+int disk_aio_setup(struct disk_image *disk)
+{
+ int r;
+ pthread_t thread;
+
+ disk->evt = eventfd(0, 0);
+ if (disk->evt < 0)
+ return -errno;
+
+ io_setup(AIO_MAX, &disk->ctx);
+ r = pthread_create(&thread, NULL, disk_aio_thread, disk);
+ if (r) {
+ r = -errno;
+ close(disk->evt);
+ return r;
+ }
+ return 0;
+}
+
+void disk_aio_destroy(struct disk_image *disk)
+{
+ close(disk->evt);
+ io_destroy(disk->ctx);
+}
diff --git a/disk/core.c b/disk/core.c
index 4c7c4f0..8988070 100644
--- a/disk/core.c
+++ b/disk/core.c
@@ -4,11 +4,8 @@
#include "kvm/kvm.h"
#include <linux/err.h>
-#include <sys/eventfd.h>
#include <poll.h>
-#define AIO_MAX 256
-
int debug_iodelay;
static int disk_image__close(struct disk_image *disk);
@@ -54,27 +51,6 @@
return 0;
}
-#ifdef CONFIG_HAS_AIO
-static void *disk_image__thread(void *param)
-{
- struct disk_image *disk = param;
- struct io_event event[AIO_MAX];
- struct timespec notime = {0};
- int nr, i;
- u64 dummy;
-
- kvm__set_thread_name("disk-image-io");
-
- while (read(disk->evt, &dummy, sizeof(dummy)) > 0) {
- nr = io_getevents(disk->ctx, 1, ARRAY_SIZE(event), event, ¬ime);
- for (i = 0; i < nr; i++)
- disk->disk_req_cb(event[i].data, event[i].res);
- }
-
- return NULL;
-}
-#endif
-
struct disk_image *disk_image__new(int fd, u64 size,
struct disk_image_operations *ops,
int use_mmap)
@@ -99,26 +75,22 @@
disk->priv = mmap(NULL, size, PROT_RW, MAP_PRIVATE | MAP_NORESERVE, fd, 0);
if (disk->priv == MAP_FAILED) {
r = -errno;
- free(disk);
- return ERR_PTR(r);
+ goto err_free_disk;
}
}
-#ifdef CONFIG_HAS_AIO
- {
- pthread_t thread;
+ r = disk_aio_setup(disk);
+ if (r)
+ goto err_unmap_disk;
- disk->evt = eventfd(0, 0);
- io_setup(AIO_MAX, &disk->ctx);
- r = pthread_create(&thread, NULL, disk_image__thread, disk);
- if (r) {
- r = -errno;
- free(disk);
- return ERR_PTR(r);
- }
- }
-#endif
return disk;
+
+err_unmap_disk:
+ if (disk->priv)
+ munmap(disk->priv, size);
+err_free_disk:
+ free(disk);
+ return ERR_PTR(r);
}
static struct disk_image *disk_image__open(const char *filename, bool readonly, bool direct)
@@ -243,6 +215,8 @@
if (!disk)
return 0;
+ disk_aio_destroy(disk);
+
if (disk->ops->close)
return disk->ops->close(disk);
diff --git a/disk/raw.c b/disk/raw.c
index 93b2b4e..09da7e0 100644
--- a/disk/raw.c
+++ b/disk/raw.c
@@ -2,38 +2,17 @@
#include <linux/err.h>
-#ifdef CONFIG_HAS_AIO
-#include <libaio.h>
-#endif
-
-ssize_t raw_image__read(struct disk_image *disk, u64 sector, const struct iovec *iov,
+ssize_t raw_image__read_sync(struct disk_image *disk, u64 sector, const struct iovec *iov,
int iovcount, void *param)
{
- u64 offset = sector << SECTOR_SHIFT;
-
-#ifdef CONFIG_HAS_AIO
- struct iocb iocb;
-
- return aio_preadv(disk->ctx, &iocb, disk->fd, iov, iovcount, offset,
- disk->evt, param);
-#else
- return preadv_in_full(disk->fd, iov, iovcount, offset);
-#endif
+ return preadv_in_full(disk->fd, iov, iovcount, sector << SECTOR_SHIFT);
}
-ssize_t raw_image__write(struct disk_image *disk, u64 sector, const struct iovec *iov,
- int iovcount, void *param)
+ssize_t raw_image__write_sync(struct disk_image *disk, u64 sector,
+ const struct iovec *iov, int iovcount,
+ void *param)
{
- u64 offset = sector << SECTOR_SHIFT;
-
-#ifdef CONFIG_HAS_AIO
- struct iocb iocb;
-
- return aio_pwritev(disk->ctx, &iocb, disk->fd, iov, iovcount, offset,
- disk->evt, param);
-#else
- return pwritev_in_full(disk->fd, iov, iovcount, offset);
-#endif
+ return pwritev_in_full(disk->fd, iov, iovcount, sector << SECTOR_SHIFT);
}
ssize_t raw_image__read_mmap(struct disk_image *disk, u64 sector, const struct iovec *iov,
@@ -79,12 +58,6 @@
if (disk->priv != MAP_FAILED)
ret = munmap(disk->priv, disk->size);
- close(disk->evt);
-
-#ifdef CONFIG_HAS_VIRTIO
- io_destroy(disk->ctx);
-#endif
-
return ret;
}
diff --git a/include/kvm/disk-image.h b/include/kvm/disk-image.h
index 4746e88..953beb2 100644
--- a/include/kvm/disk-image.h
+++ b/include/kvm/disk-image.h
@@ -19,6 +19,10 @@
#include <unistd.h>
#include <fcntl.h>
+#ifdef CONFIG_HAS_AIO
+#include <libaio.h>
+#endif
+
#define SECTOR_SHIFT 9
#define SECTOR_SIZE (1UL << SECTOR_SHIFT)
@@ -61,10 +65,10 @@
void (*disk_req_cb)(void *param, long len);
bool readonly;
bool async;
- int evt;
#ifdef CONFIG_HAS_AIO
io_context_t ctx;
-#endif
+ int evt;
+#endif /* CONFIG_HAS_AIO */
const char *wwpn;
const char *tpgt;
int debug_iodelay;
@@ -84,14 +88,39 @@
struct disk_image *raw_image__probe(int fd, struct stat *st, bool readonly);
struct disk_image *blkdev__probe(const char *filename, int flags, struct stat *st);
-ssize_t raw_image__read(struct disk_image *disk, u64 sector,
- const struct iovec *iov, int iovcount, void *param);
-ssize_t raw_image__write(struct disk_image *disk, u64 sector,
- const struct iovec *iov, int iovcount, void *param);
+ssize_t raw_image__read_sync(struct disk_image *disk, u64 sector,
+ const struct iovec *iov, int iovcount, void *param);
+ssize_t raw_image__write_sync(struct disk_image *disk, u64 sector,
+ const struct iovec *iov, int iovcount, void *param);
ssize_t raw_image__read_mmap(struct disk_image *disk, u64 sector,
const struct iovec *iov, int iovcount, void *param);
ssize_t raw_image__write_mmap(struct disk_image *disk, u64 sector,
const struct iovec *iov, int iovcount, void *param);
int raw_image__close(struct disk_image *disk);
void disk_image__set_callback(struct disk_image *disk, void (*disk_req_cb)(void *param, long len));
+
+#ifdef CONFIG_HAS_AIO
+int disk_aio_setup(struct disk_image *disk);
+void disk_aio_destroy(struct disk_image *disk);
+ssize_t raw_image__read_async(struct disk_image *disk, u64 sector,
+ const struct iovec *iov, int iovcount, void *param);
+ssize_t raw_image__write_async(struct disk_image *disk, u64 sector,
+ const struct iovec *iov, int iovcount, void *param);
+
+#define raw_image__read raw_image__read_async
+#define raw_image__write raw_image__write_async
+
+#else /* !CONFIG_HAS_AIO */
+static inline int disk_aio_setup(struct disk_image *disk)
+{
+ /* No-op */
+ return 0;
+}
+static inline void disk_aio_destroy(struct disk_image *disk)
+{
+}
+#define raw_image__read raw_image__read_sync
+#define raw_image__write raw_image__write_sync
+#endif /* CONFIG_HAS_AIO */
+
#endif /* KVM__DISK_IMAGE_H */
diff --git a/include/kvm/read-write.h b/include/kvm/read-write.h
index acbd6f0..8375d7c 100644
--- a/include/kvm/read-write.h
+++ b/include/kvm/read-write.h
@@ -5,10 +5,6 @@
#include <sys/uio.h>
#include <unistd.h>
-#ifdef CONFIG_HAS_AIO
-#include <libaio.h>
-#endif
-
ssize_t xread(int fd, void *buf, size_t count);
ssize_t xwrite(int fd, const void *buf, size_t count);
@@ -35,11 +31,4 @@
ssize_t preadv_in_full(int fd, const struct iovec *iov, int iovcnt, off_t offset);
ssize_t pwritev_in_full(int fd, const struct iovec *iov, int iovcnt, off_t offset);
-#ifdef CONFIG_HAS_AIO
-int aio_preadv(io_context_t ctx, struct iocb *iocb, int fd, const struct iovec *iov, int iovcnt,
- off_t offset, int ev, void *param);
-int aio_pwritev(io_context_t ctx, struct iocb *iocb, int fd, const struct iovec *iov, int iovcnt,
- off_t offset, int ev, void *param);
-#endif
-
#endif /* KVM_READ_WRITE_H */
diff --git a/util/read-write.c b/util/read-write.c
index bf6fb2f..06fc0df 100644
--- a/util/read-write.c
+++ b/util/read-write.c
@@ -337,39 +337,3 @@
return total;
}
-
-#ifdef CONFIG_HAS_AIO
-int aio_pwritev(io_context_t ctx, struct iocb *iocb, int fd, const struct iovec *iov, int iovcnt,
- off_t offset, int ev, void *param)
-{
- struct iocb *ios[1] = { iocb };
- int ret;
-
- io_prep_pwritev(iocb, fd, iov, iovcnt, offset);
- io_set_eventfd(iocb, ev);
- iocb->data = param;
-
-restart:
- ret = io_submit(ctx, 1, ios);
- if (ret == -EAGAIN)
- goto restart;
- return ret;
-}
-
-int aio_preadv(io_context_t ctx, struct iocb *iocb, int fd, const struct iovec *iov, int iovcnt,
- off_t offset, int ev, void *param)
-{
- struct iocb *ios[1] = { iocb };
- int ret;
-
- io_prep_preadv(iocb, fd, iov, iovcnt, offset);
- io_set_eventfd(iocb, ev);
- iocb->data = param;
-
-restart:
- ret = io_submit(ctx, 1, ios);
- if (ret == -EAGAIN)
- goto restart;
- return ret;
-}
-#endif
