Struct BDRVReopenState introduced for handling reopen state of images.
This can be extended by each of the block drivers to reopen respective
image files. Implementation for raw-posix is done here.
Signed-off-by: Supriya Kannery <supri...@linux.vnet.ibm.com>
---
block.c | 46 ++++++++++++++++++++++++++++++++--------
block/raw-posix.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
block_int.h | 15 +++++++++++++
3 files changed, 114 insertions(+), 9 deletions(-)
Index: qemu/block/raw-posix.c
===================================================================
--- qemu.orig/block/raw-posix.c
+++ qemu/block/raw-posix.c
@@ -279,6 +279,66 @@ static int raw_open(BlockDriverState *bs
return raw_open_common(bs, filename, flags, 0);
}
+static int raw_reopen_prepare(BlockDriverState *bs, BDRVReopenState **rs,
+ int flags)
+{
+ BDRVReopenState *raw_rs = g_malloc0(sizeof(BDRVReopenState));
+ BDRVRawState *s = bs->opaque;
+
+ raw_rs->bs = bs;
+ raw_rs->reopen_flags = flags;
+ raw_rs->reopen_fd = -1;
+
+ /* If only O_DIRECT to be toggled, use fcntl */
+ if (!((bs->open_flags & ~BDRV_O_NOCACHE) ^
+ (flags & ~BDRV_O_NOCACHE))) {
+ raw_rs->reopen_fd = dup(s->fd);
+ if (raw_rs->reopen_fd <= 0) {
+ return -1;
+ }
+ }
+
+ /* TBD: Handle O_DSYNC and other flags */
+ *rs = raw_rs;
+ return 0;
+}
+
+static int raw_reopen_commit(BDRVReopenState *rs)
+{
+ BlockDriverState *bs = rs->bs;
+ BDRVRawState *s = bs->opaque;
+
+ if (!rs->reopen_fd) {
+ return -1;
+ }
+
+ int ret = fcntl_setfl(rs->reopen_fd, rs->reopen_flags);
+ if (ret < 0) {
+ return ret;
+ }
+
+ /* Set new flags, so replace old fd with new one */
+ close(s->fd);
+ s->fd = rs->reopen_fd;
+ s->open_flags = bs->open_flags = rs->reopen_flags;
+ g_free(rs);
+ rs = NULL;
+
+ return 0;
+}
+
+static int raw_reopen_abort(BDRVReopenState *rs)
+{
+ if (rs->reopen_fd != -1) {
+ close(rs->reopen_fd);
+ rs->reopen_fd = -1;
+ rs->reopen_flags = 0;
+ }
+ g_free(rs);
+ rs = NULL;
+ return 0;
+}
+
/* XXX: use host sector size if necessary with:
#ifdef DIOCGSECTORSIZE
{
@@ -896,6 +956,9 @@ static BlockDriver bdrv_file = {
.instance_size = sizeof(BDRVRawState),
.bdrv_probe = NULL, /* no probe for protocols */
.bdrv_file_open = raw_open,
+ .bdrv_reopen_prepare = raw_reopen_prepare,
+ .bdrv_reopen_commit = raw_reopen_commit,
+ .bdrv_reopen_abort = raw_reopen_abort,
.bdrv_read = raw_read,
.bdrv_write = raw_write,
.bdrv_close = raw_close,
@@ -1166,6 +1229,10 @@ static BlockDriver bdrv_host_device = {
.instance_size = sizeof(BDRVRawState),
.bdrv_probe_device = hdev_probe_device,
.bdrv_file_open = hdev_open,
+ .bdrv_reopen_prepare
+ = raw_reopen_prepare,
+ .bdrv_reopen_commit = raw_reopen_commit,
+ .bdrv_reopen_abort = raw_reopen_abort,
.bdrv_close = raw_close,
.bdrv_create = hdev_create,
.create_options = raw_create_options,
Index: qemu/block.c
===================================================================
--- qemu.orig/block.c
+++ qemu/block.c
@@ -706,6 +706,7 @@ int bdrv_reopen(BlockDriverState *bs, in
{
BlockDriver *drv = bs->drv;
int ret = 0, open_flags;
+ BDRVReopenState *rs;
/* Quiesce IO for the given block device */
qemu_aio_flush();
@@ -713,20 +714,48 @@ int bdrv_reopen(BlockDriverState *bs, in
qerror_report(QERR_DATA_SYNC_FAILED, bs->device_name);
return ret;
}
- open_flags = bs->open_flags;
- bdrv_close(bs);
- ret = bdrv_open(bs, bs->filename, bdrv_flags, drv);
- if (ret < 0) {
- /* Reopen failed. Try to open with original flags */
- qerror_report(QERR_REOPEN_FILE_FAILED, bs->filename);
- ret = bdrv_open(bs, bs->filename, open_flags, drv);
+ /* Use driver specific reopen() if available */
+ if (drv->bdrv_reopen_prepare) {
+ ret = drv->bdrv_reopen_prepare(bs, &rs, bdrv_flags);
if (ret < 0) {
- /* Reopen failed with orig and modified flags */
- abort();
+ goto fail;
}
- }
+ if (drv->bdrv_reopen_commit) {
+ ret = drv->bdrv_reopen_commit(rs);
+ if (ret < 0) {
+ goto fail;
+ }
+ return 0;
+ }
+fail:
+ if (drv->bdrv_reopen_abort) {
+ ret = drv->bdrv_reopen_abort(rs);
+ qerror_report(QERR_REOPEN_FILE_FAILED, bs->filename);
+ return ret;
+ }
+
+ } else {
+
+ /* Use reopen procedure common for all drivers */
+ open_flags = bs->open_flags;
+ bdrv_close(bs);
+ ret = bdrv_open(bs, bs->filename, bdrv_flags, drv);
+ if (ret < 0) {
+ /*
+ * Reopen failed. Try to open with original flags
+ */
+ qerror_report(QERR_REOPEN_FILE_FAILED, bs->filename);
+ ret = bdrv_open(bs, bs->filename, open_flags, drv);
+ if (ret < 0) {
+ /*
+ * Reopen with orig and modified flags failed
+ */
+ abort();
+ }
+ }
+ }
return ret;
}
Index: qemu/block_int.h
===================================================================
--- qemu.orig/block_int.h
+++ qemu/block_int.h
@@ -55,6 +55,13 @@ struct BlockDriver {
int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
int (*bdrv_probe_device)(const char *filename);
int (*bdrv_open)(BlockDriverState *bs, int flags);
+
+ /* For handling image reopen for split or non-split files */
+ int (*bdrv_reopen_prepare)(BlockDriverState *bs, BDRVReopenState **rs,
+ int flags);
+ int (*bdrv_reopen_commit)(BDRVReopenState *rs);
+ int (*bdrv_reopen_abort)(BDRVReopenState *rs);
+
int (*bdrv_file_open)(BlockDriverState *bs, const char *filename, int
flags);
int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors);
@@ -207,6 +214,14 @@ struct BlockDriverState {
void *private;
};
+struct BDRVReopenState {
+ BlockDriverState *bs;
+ int reopen_flags;
+
+ /* For raw-posix */
+ int reopen_fd;
+};
+
struct BlockDriverAIOCB {
AIOPool *pool;
BlockDriverState *bs;
Index: qemu/qemu-common.h
===================================================================
--- qemu.orig/qemu-common.h
+++ qemu/qemu-common.h
@@ -228,6 +228,7 @@ typedef struct NICInfo NICInfo;
typedef struct HCIInfo HCIInfo;
typedef struct AudioState AudioState;
typedef struct BlockDriverState BlockDriverState;
+typedef struct BDRVReopenState BDRVReopenState;
typedef struct DriveInfo DriveInfo;
typedef struct DisplayState DisplayState;
typedef struct DisplayChangeListener DisplayChangeListener;
Index: qemu/block/raw.c
===================================================================
--- qemu.orig/block/raw.c
+++ qemu/block/raw.c
@@ -9,6 +9,15 @@ static int raw_open(BlockDriverState *bs
return 0;
}
+static int raw_reopen(BlockDriverState *bs, BDRVReopenState **prs, int flags)
+{
+ int ret = bdrv_reopen(bs->file, flags);
+ if (!ret) {
+ bs->open_flags = bs->file->open_flags;
+ }
+ return ret;
+}
+
static int raw_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
@@ -128,6 +137,8 @@ static BlockDriver bdrv_raw = {
.instance_size = 1,
.bdrv_open = raw_open,
+ .bdrv_reopen_prepare
+ = raw_reopen,
.bdrv_close = raw_close,
.bdrv_read = raw_read,
.bdrv_write = raw_write,
