[PATCH 13/14] block/file-posix: implement .bdrv_close_safe

[Vladimir Sementsov-Ogievskiy]

Implement new close API for 'file' driver, so that we now have the
minimal set working: qcow2 + file.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/file-posix.c | 38 +++++++++++++++++++++++++++++++-------
 1 file changed, 31 insertions(+), 7 deletions(-)

diff --git a/block/file-posix.c b/block/file-posix.c
index 1f1756e192..90642d8185 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -2195,14 +2195,38 @@ static void raw_aio_attach_aio_context(BlockDriverState 
*bs,
 #endif
 }
 
-static void raw_close(BlockDriverState *bs)
+static void raw_close_commit(void *opaque)
+{
+    BDRVRawState *s = opaque;
+
+    if (s->fd >= 0) {
+        /*
+         * Closing fd is unrecoverable action, that's why it is in .commit.
+         * So, yes, it may fail, but we ignore the failure.
+         */
+        qemu_close(s->fd);
+        s->fd = -1;
+    }
+}
+
+TransactionActionDrv raw_close_drv = {
+    .commit = raw_close_commit,
+};
+
+static int raw_close_safe(BlockDriverState *bs, Transaction *tran,
+                          Error **errp)
 {
     BDRVRawState *s = bs->opaque;
 
     if (s->fd >= 0) {
-        qemu_close(s->fd);
-        s->fd = -1;
+        if (tran) {
+            tran_add(tran, &raw_close_drv, s);
+        } else {
+            raw_close_commit(s);
+        }
     }
+
+    return 0;
 }
 
 /**
@@ -3278,7 +3302,7 @@ BlockDriver bdrv_file = {
     .bdrv_reopen_prepare = raw_reopen_prepare,
     .bdrv_reopen_commit = raw_reopen_commit,
     .bdrv_reopen_abort = raw_reopen_abort,
-    .bdrv_close = raw_close,
+    .bdrv_close_safe = raw_close_safe,
     .bdrv_co_create = raw_co_create,
     .bdrv_co_create_opts = raw_co_create_opts,
     .bdrv_has_zero_init = bdrv_has_zero_init_1,
@@ -3643,7 +3667,7 @@ static BlockDriver bdrv_host_device = {
     .bdrv_probe_device  = hdev_probe_device,
     .bdrv_parse_filename = hdev_parse_filename,
     .bdrv_file_open     = hdev_open,
-    .bdrv_close         = raw_close,
+    .bdrv_close_safe    = raw_close_safe,
     .bdrv_reopen_prepare = raw_reopen_prepare,
     .bdrv_reopen_commit  = raw_reopen_commit,
     .bdrv_reopen_abort   = raw_reopen_abort,
@@ -3771,7 +3795,7 @@ static BlockDriver bdrv_host_cdrom = {
     .bdrv_probe_device = cdrom_probe_device,
     .bdrv_parse_filename = cdrom_parse_filename,
     .bdrv_file_open     = cdrom_open,
-    .bdrv_close         = raw_close,
+    .bdrv_close_safe    = raw_close_safe,
     .bdrv_reopen_prepare = raw_reopen_prepare,
     .bdrv_reopen_commit  = raw_reopen_commit,
     .bdrv_reopen_abort   = raw_reopen_abort,
@@ -3902,7 +3926,7 @@ static BlockDriver bdrv_host_cdrom = {
     .bdrv_probe_device = cdrom_probe_device,
     .bdrv_parse_filename = cdrom_parse_filename,
     .bdrv_file_open     = cdrom_open,
-    .bdrv_close         = raw_close,
+    .bdrv_close_safe    = raw_close_safe,
     .bdrv_reopen_prepare = raw_reopen_prepare,
     .bdrv_reopen_commit  = raw_reopen_commit,
     .bdrv_reopen_abort   = raw_reopen_abort,
-- 
2.31.1