The thought is that this support can be added in the future, but is
not required for the initial fd: support.
This patch was tested with the following formats: raw, cow, qcow,
qcow2, qed, and vmdk, using the fd: protocol from the command line
and the monitor. Tests were also run to verify existing file name
support and qemu-img were not regressed. Non-valid file descriptors,
fd: without format, snapshot and backing files were also tested.
Signed-off-by: Corey Bryant<address@hidden>
---
block.c | 16 ++++++++++
block.h | 1 +
block/cow.c | 5 +++
block/qcow.c | 5 +++
block/qcow2.c | 5 +++
block/qed.c | 4 ++
block/raw-posix.c | 81
+++++++++++++++++++++++++++++++++++++++++++++++------
block/vmdk.c | 5 +++
block_int.h | 1 +
blockdev.c | 10 ++++++
monitor.c | 5 +++
monitor.h | 1 +
qemu-options.hx | 8 +++--
qemu-tool.c | 5 +++
14 files changed, 140 insertions(+), 12 deletions(-)
diff --git a/block.c b/block.c
index 24a25d5..500db84 100644
--- a/block.c
+++ b/block.c
@@ -536,6 +536,10 @@ int bdrv_open(BlockDriverState *bs, const char
*filename, int flags,
char tmp_filename[PATH_MAX];
char backing_filename[PATH_MAX];
+ if (bdrv_is_fd_protocol(bs)) {
+ return -ENOTSUP;
+ }
+
/* if snapshot, we create a temporary backing file and open
it
instead of opening 'filename' directly */
@@ -585,6 +589,10 @@ int bdrv_open(BlockDriverState *bs, const char
*filename, int flags,
/* Find the right image format driver */
if (!drv) {
+ /* format must be specified for fd: protocol */
+ if (bdrv_is_fd_protocol(bs)) {
+ return -ENOTSUP;
+ }
ret = find_image_format(filename,&drv);
}
@@ -1460,6 +1468,11 @@ int bdrv_enable_write_cache(BlockDriverState
*bs)
return bs->enable_write_cache;
}
+int bdrv_is_fd_protocol(BlockDriverState *bs)
+{
+ return bs->fd_protocol;
+}
+
/* XXX: no longer used */
void bdrv_set_change_cb(BlockDriverState *bs,
void (*change_cb)(void *opaque, int reason),
@@ -1964,6 +1977,9 @@ int bdrv_snapshot_create(BlockDriverState *bs,
BlockDriver *drv = bs->drv;
if (!drv)
return -ENOMEDIUM;
+ if (bdrv_is_fd_protocol(bs)) {
+ return -ENOTSUP;
+ }
if (drv->bdrv_snapshot_create)
return drv->bdrv_snapshot_create(bs, sn_info);
if (bs->file)
diff --git a/block.h b/block.h
index da7d39c..dd46d52 100644
--- a/block.h
+++ b/block.h
@@ -182,6 +182,7 @@ int bdrv_is_removable(BlockDriverState *bs);
int bdrv_is_read_only(BlockDriverState *bs);
int bdrv_is_sg(BlockDriverState *bs);
int bdrv_enable_write_cache(BlockDriverState *bs);
+int bdrv_is_fd_protocol(BlockDriverState *bs);
int bdrv_is_inserted(BlockDriverState *bs);
int bdrv_media_changed(BlockDriverState *bs);
int bdrv_is_locked(BlockDriverState *bs);
diff --git a/block/cow.c b/block/cow.c
index 4cf543c..e17f8e7 100644
--- a/block/cow.c
+++ b/block/cow.c
@@ -82,6 +82,11 @@ static int cow_open(BlockDriverState *bs, int
flags)
pstrcpy(bs->backing_file, sizeof(bs->backing_file),
cow_header.backing_file);
+ if (bs->backing_file[0] != '\0'&& bdrv_is_fd_protocol(bs)) {
+ /* backing file currently not supported by fd: protocol */
+ goto fail;
+ }
+
bitmap_size = ((bs->total_sectors + 7)>> 3) +
sizeof(cow_header);
s->cow_sectors_offset = (bitmap_size + 511)& ~511;
return 0;
diff --git a/block/qcow.c b/block/qcow.c
index a26c886..1e46bdb 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -157,6 +157,11 @@ static int qcow_open(BlockDriverState *bs, int
flags)
if (bdrv_pread(bs->file, header.backing_file_offset,
bs->backing_file, len) != len)
goto fail;
bs->backing_file[len] = '\0';
+
+ if (bs->backing_file[0] != '\0'&& bdrv_is_fd_protocol(bs)) {
+ /* backing file currently not supported by fd: protocol
*/
+ goto fail;
+ }
}
return 0;
diff --git a/block/qcow2.c b/block/qcow2.c
index 8451ded..8b9c160 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -270,6 +270,11 @@ static int qcow2_open(BlockDriverState *bs, int
flags)
goto fail;
}
bs->backing_file[len] = '\0';
+
+ if (bs->backing_file[0] != '\0'&& bdrv_is_fd_protocol(bs)) {
+ ret = -ENOTSUP;
+ goto fail;
+ }
}
if (qcow2_read_snapshots(bs)< 0) {
ret = -EINVAL;
diff --git a/block/qed.c b/block/qed.c
index 3970379..5028897 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -446,6 +446,10 @@ static int bdrv_qed_open(BlockDriverState *bs,
int flags)
return ret;
}
+ if (bs->backing_file[0] != '\0'&& bdrv_is_fd_protocol(bs)) {
+ return -ENOTSUP;
+ }
+
if (s->header.features& QED_F_BACKING_FORMAT_NO_PROBE) {
pstrcpy(bs->backing_format, sizeof(bs->backing_format),
"raw");
}
diff --git a/block/raw-posix.c b/block/raw-posix.c
index 4cd7d7a..c72de3d 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -28,6 +28,7 @@
#include "block_int.h"
#include "module.h"
#include "block/raw-posix-aio.h"
+#include "monitor.h"
#ifdef CONFIG_COCOA
#include<paths.h>
@@ -183,7 +184,8 @@ static int raw_open_common(BlockDriverState *bs,
const char *filename,
int bdrv_flags, int open_flags)
{
BDRVRawState *s = bs->opaque;
- int fd, ret;
+ int fd = -1;
+ int ret;
ret = raw_normalize_devicepath(&filename);
if (ret != 0) {
@@ -205,15 +207,17 @@ static int raw_open_common(BlockDriverState *bs,
const char *filename,
if (!(bdrv_flags& BDRV_O_CACHE_WB))
s->open_flags |= O_DSYNC;
- s->fd = -1;
- fd = qemu_open(filename, s->open_flags, 0644);
- if (fd< 0) {
- ret = -errno;
- if (ret == -EROFS)
- ret = -EACCES;
- return ret;
+ if (s->fd == -1) {
+ fd = qemu_open(filename, s->open_flags, 0644);
+ if (fd< 0) {
+ ret = -errno;
+ if (ret == -EROFS) {
+ ret = -EACCES;
+ }
+ return ret;
+ }
+ s->fd = fd;
}
- s->fd = fd;
s->aligned_buf = NULL;
if ((bdrv_flags& BDRV_O_NOCACHE)) {
@@ -270,6 +274,7 @@ static int raw_open(BlockDriverState *bs, const
char *filename, int flags)
{
BDRVRawState *s = bs->opaque;
+ s->fd = -1;
s->type = FTYPE_FILE;
return raw_open_common(bs, filename, flags, 0);
}
@@ -890,6 +895,60 @@ static BlockDriver bdrv_file = {
.create_options = raw_create_options,
};
+static int raw_open_fd(BlockDriverState *bs, const char *filename,
int flags)
+{
+ BDRVRawState *s = bs->opaque;
+ const char *fd_str;
+ int fd;
+
+ /* extract the file descriptor - fail if it's not fd: */
+ if (!strstart(filename, "fd:",&fd_str)) {
+ return -EINVAL;
+ }
+
+ if (!qemu_isdigit(fd_str[0])) {
+ /* get fd from monitor */
+ fd = qemu_get_fd(fd_str);
+ if (fd == -1) {
+ return -EBADF;
+ }
+ } else {
+ char *endptr = NULL;
+
+ fd = strtol(fd_str,&endptr, 10);
+ if (*endptr || (fd == 0&& fd_str == endptr)) {
+ return -EBADF;
+ }
+ }
+
+ s->fd = fd;
+ s->type = FTYPE_FILE;
+
+ return raw_open_common(bs, filename, flags, 0);
+}
+
+static BlockDriver bdrv_file_fd = {
+ .format_name = "file",
+ .protocol_name = "fd",
+ .instance_size = sizeof(BDRVRawState),
+ .bdrv_probe = NULL, /* no probe for protocols */
+ .bdrv_file_open = raw_open_fd,
+ .bdrv_read = raw_read,
+ .bdrv_write = raw_write,
+ .bdrv_close = raw_close,
+ .bdrv_flush = raw_flush,
+ .bdrv_discard = raw_discard,
+
+ .bdrv_aio_readv = raw_aio_readv,
+ .bdrv_aio_writev = raw_aio_writev,
+ .bdrv_aio_flush = raw_aio_flush,
+
+ .bdrv_truncate = raw_truncate,
+ .bdrv_getlength = raw_getlength,
+
+ .create_options = raw_create_options,
+};
+
/***********************************************/
/* host device */
@@ -998,6 +1057,7 @@ static int hdev_open(BlockDriverState *bs, const
char *filename, int flags)
}
#endif
+ s->fd = -1;
s->type = FTYPE_FILE;
#if defined(__linux__)
{
@@ -1168,6 +1228,7 @@ static int floppy_open(BlockDriverState *bs,
const char *filename, int flags)
BDRVRawState *s = bs->opaque;
int ret;
+ s->fd = -1;
s->type = FTYPE_FD;
/* open will not fail even if no floppy is inserted, so add
O_NONBLOCK */
@@ -1280,6 +1341,7 @@ static int cdrom_open(BlockDriverState *bs,
const char *filename, int flags)
{
BDRVRawState *s = bs->opaque;
+ s->fd = -1;
s->type = FTYPE_CD;
/* open will not fail even if no CD is inserted, so add
O_NONBLOCK */
@@ -1503,6 +1565,7 @@ static void bdrv_file_init(void)
* Register all the drivers. Note that order is important, the
driver
* registered last will get probed first.
*/
+ bdrv_register(&bdrv_file_fd);
bdrv_register(&bdrv_file);
bdrv_register(&bdrv_host_device);
#ifdef __linux__
diff --git a/block/vmdk.c b/block/vmdk.c
index 922b23d..2ea808e 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -353,6 +353,11 @@ static int vmdk_parent_open(BlockDriverState *bs)
return -1;
pstrcpy(bs->backing_file, end_name - p_name + 1, p_name);
+
+ if (bs->backing_file[0] != '\0'&& bdrv_is_fd_protocol(bs)) {
+ /* backing file currently not supported by fd: protocol
*/
+ return -1;
+ }
}
return 0;
diff --git a/block_int.h b/block_int.h
index fa91337..a305ee2 100644
--- a/block_int.h
+++ b/block_int.h
@@ -152,6 +152,7 @@ struct BlockDriverState {
int encrypted; /* if true, the media is encrypted */
int valid_key; /* if true, a valid encryption key has been set */
int sg; /* if true, the device is a /dev/sg* */
+ int fd_protocol; /* if true, the fd: protocol was specified */