Patchwork [V2,1/5] block: package preparation code in qmp_transaction()

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Submitter Wayne Xia
Date April 13, 2013, 11:11 a.m.
Message ID <1365851501-3037-2-git-send-email-xiawenc@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/236325/
State New
Headers show

Comments

Wayne Xia - April 13, 2013, 11:11 a.m.
The code before really committing is moved into a function. Most
code are simply moved from qmp_transaction()i, except fail handling
label is changed from "delete_and_fail" to "fail". Other code such
as input parsing is not touched, to make it easier in review.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
---
 blockdev.c |  146 +++++++++++++++++++++++++++++++++--------------------------
 1 files changed, 82 insertions(+), 64 deletions(-)
Kevin Wolf - April 16, 2013, 1:19 p.m.
Am 13.04.2013 um 13:11 hat Wenchao Xia geschrieben:
>   The code before really committing is moved into a function. Most

This line seems to be indented accidentally?

> code are simply moved from qmp_transaction()i, except fail handling
> label is changed from "delete_and_fail" to "fail". Other code such
> as input parsing is not touched, to make it easier in review.
> 
> Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
> ---
>  blockdev.c |  146 +++++++++++++++++++++++++++++++++--------------------------
>  1 files changed, 82 insertions(+), 64 deletions(-)
> 
> diff --git a/blockdev.c b/blockdev.c
> index 8a1652b..e01906c 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -785,6 +785,84 @@ typedef struct BlkTransactionStates {
>      QSIMPLEQ_ENTRY(BlkTransactionStates) entry;
>  } BlkTransactionStates;
>  
> +static int external_snapshot_prepare(const char *device,
> +                                     const char *format,
> +                                     const char *new_image_file,
> +                                     enum NewImageMode mode,
> +                                     BlkTransactionStates *states,
> +                                     Error **errp)

One error reporting mechanism is enough, so this function should return
void.

Kevin
Eric Blake - April 16, 2013, 2:56 p.m.
On 04/13/2013 05:11 AM, Wenchao Xia wrote:
>   The code before really committing is moved into a function. Most
> code are simply moved from qmp_transaction()i, except fail handling

s/i,/,/

> label is changed from "delete_and_fail" to "fail". Other code such
> as input parsing is not touched, to make it easier in review.
> 
> Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
> ---
>  blockdev.c |  146 +++++++++++++++++++++++++++++++++--------------------------
>  1 files changed, 82 insertions(+), 64 deletions(-)
>

Patch

diff --git a/blockdev.c b/blockdev.c
index 8a1652b..e01906c 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -785,6 +785,84 @@  typedef struct BlkTransactionStates {
     QSIMPLEQ_ENTRY(BlkTransactionStates) entry;
 } BlkTransactionStates;
 
+static int external_snapshot_prepare(const char *device,
+                                     const char *format,
+                                     const char *new_image_file,
+                                     enum NewImageMode mode,
+                                     BlkTransactionStates *states,
+                                     Error **errp)
+{
+    BlockDriver *proto_drv;
+    BlockDriver *drv;
+    int flags, ret;
+    Error *local_err = NULL;
+
+    drv = bdrv_find_format(format);
+    if (!drv) {
+        error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
+        goto fail;
+    }
+
+    states->old_bs = bdrv_find(device);
+    if (!states->old_bs) {
+        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+        goto fail;
+    }
+
+    if (!bdrv_is_inserted(states->old_bs)) {
+        error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
+        goto fail;
+    }
+
+    if (bdrv_in_use(states->old_bs)) {
+        error_set(errp, QERR_DEVICE_IN_USE, device);
+        goto fail;
+    }
+
+    if (!bdrv_is_read_only(states->old_bs)) {
+        if (bdrv_flush(states->old_bs)) {
+            error_set(errp, QERR_IO_ERROR);
+            goto fail;
+        }
+    }
+
+    flags = states->old_bs->open_flags;
+
+    proto_drv = bdrv_find_protocol(new_image_file);
+    if (!proto_drv) {
+        error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
+        goto fail;
+    }
+
+    /* create new image w/backing file */
+    if (mode != NEW_IMAGE_MODE_EXISTING) {
+        bdrv_img_create(new_image_file, format,
+                        states->old_bs->filename,
+                        states->old_bs->drv->format_name,
+                        NULL, -1, flags, &local_err, false);
+        if (error_is_set(&local_err)) {
+            error_propagate(errp, local_err);
+            goto fail;
+        }
+    }
+
+    /* We will manually add the backing_hd field to the bs later */
+    states->new_bs = bdrv_new("");
+    /* TODO Inherit bs->options or only take explicit options with an
+     * extended QMP command? */
+    ret = bdrv_open(states->new_bs, new_image_file, NULL,
+                    flags | BDRV_O_NO_BACKING, drv);
+    if (ret != 0) {
+        error_set(errp, QERR_OPEN_FILE_FAILED, new_image_file);
+        goto fail;
+    }
+
+    return 0;
+
+ fail:
+    return -1;
+}
+
 /*
  * 'Atomic' group snapshots.  The snapshots are taken as a set, and if any fail
  *  then we do not pivot any of the devices in the group, and abandon the
@@ -792,10 +870,8 @@  typedef struct BlkTransactionStates {
  */
 void qmp_transaction(BlockdevActionList *dev_list, Error **errp)
 {
-    int ret = 0;
     BlockdevActionList *dev_entry = dev_list;
     BlkTransactionStates *states, *next;
-    Error *local_err = NULL;
 
     QSIMPLEQ_HEAD(snap_bdrv_states, BlkTransactionStates) snap_bdrv_states;
     QSIMPLEQ_INIT(&snap_bdrv_states);
@@ -806,9 +882,6 @@  void qmp_transaction(BlockdevActionList *dev_list, Error **errp)
     /* We don't do anything in this loop that commits us to the snapshot */
     while (NULL != dev_entry) {
         BlockdevAction *dev_info = NULL;
-        BlockDriver *proto_drv;
-        BlockDriver *drv;
-        int flags;
         enum NewImageMode mode;
         const char *new_image_file;
         const char *device;
@@ -831,70 +904,15 @@  void qmp_transaction(BlockdevActionList *dev_list, Error **errp)
                 format = dev_info->blockdev_snapshot_sync->format;
             }
             mode = dev_info->blockdev_snapshot_sync->mode;
+            if (external_snapshot_prepare(device, format, new_image_file,
+                                          mode, states, errp)) {
+                goto delete_and_fail;
+            }
             break;
         default:
             abort();
         }
 
-        drv = bdrv_find_format(format);
-        if (!drv) {
-            error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
-            goto delete_and_fail;
-        }
-
-        states->old_bs = bdrv_find(device);
-        if (!states->old_bs) {
-            error_set(errp, QERR_DEVICE_NOT_FOUND, device);
-            goto delete_and_fail;
-        }
-
-        if (!bdrv_is_inserted(states->old_bs)) {
-            error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
-            goto delete_and_fail;
-        }
-
-        if (bdrv_in_use(states->old_bs)) {
-            error_set(errp, QERR_DEVICE_IN_USE, device);
-            goto delete_and_fail;
-        }
-
-        if (!bdrv_is_read_only(states->old_bs)) {
-            if (bdrv_flush(states->old_bs)) {
-                error_set(errp, QERR_IO_ERROR);
-                goto delete_and_fail;
-            }
-        }
-
-        flags = states->old_bs->open_flags;
-
-        proto_drv = bdrv_find_protocol(new_image_file);
-        if (!proto_drv) {
-            error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
-            goto delete_and_fail;
-        }
-
-        /* create new image w/backing file */
-        if (mode != NEW_IMAGE_MODE_EXISTING) {
-            bdrv_img_create(new_image_file, format,
-                            states->old_bs->filename,
-                            states->old_bs->drv->format_name,
-                            NULL, -1, flags, &local_err, false);
-            if (error_is_set(&local_err)) {
-                error_propagate(errp, local_err);
-                goto delete_and_fail;
-            }
-        }
-
-        /* We will manually add the backing_hd field to the bs later */
-        states->new_bs = bdrv_new("");
-        /* TODO Inherit bs->options or only take explicit options with an
-         * extended QMP command? */
-        ret = bdrv_open(states->new_bs, new_image_file, NULL,
-                        flags | BDRV_O_NO_BACKING, drv);
-        if (ret != 0) {
-            error_set(errp, QERR_OPEN_FILE_FAILED, new_image_file);
-            goto delete_and_fail;
-        }
     }