block: Convert bdrv_eject() to co_wrapper

bdrv_eject() is categorized as an I/O function, and it currently
doesn't run in a coroutine. We should let it take a graph rdlock since
it traverses the block nodes graph, which however is only possible in a
coroutine.

The only caller of this function is blk_eject(). Therefore make
blk_eject() a co_wrapper, so that it always creates a new coroutine, and
then make bdrv_eject() coroutine_fn where the lock can be taken.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-12-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block.c

@@ -6821,13 +6821,13 @@ bool coroutine_fn bdrv_co_is_inserted(BlockDriverState *bs)
 /**
  * If eject_flag is TRUE, eject the media. Otherwise, close the tray
  */
-void bdrv_eject(BlockDriverState *bs, bool eject_flag)
+void coroutine_fn bdrv_co_eject(BlockDriverState *bs, bool eject_flag)
 {
     BlockDriver *drv = bs->drv;
     IO_CODE();
 
-    if (drv && drv->bdrv_eject) {
+    if (drv && drv->bdrv_co_eject) {
-        drv->bdrv_eject(bs, eject_flag);
+        drv->bdrv_co_eject(bs, eject_flag);
     }
 }
 

block/block-backend.c

@@ -2009,14 +2009,14 @@ void blk_lock_medium(BlockBackend *blk, bool locked)
     }
 }
 
-void blk_eject(BlockBackend *blk, bool eject_flag)
+void coroutine_fn blk_co_eject(BlockBackend *blk, bool eject_flag)
 {
     BlockDriverState *bs = blk_bs(blk);
     char *id;
     IO_CODE();
 
     if (bs) {
-        bdrv_eject(bs, eject_flag);
+        bdrv_co_eject(bs, eject_flag);
     }
 
     /* Whether or not we ejected on the backend,

block/copy-on-read.c

@@ -217,9 +217,9 @@ static int coroutine_fn cor_co_pwritev_compressed(BlockDriverState *bs,
 }
 
 
-static void cor_eject(BlockDriverState *bs, bool eject_flag)
+static void coroutine_fn cor_co_eject(BlockDriverState *bs, bool eject_flag)
 {
-    bdrv_eject(bs->file->bs, eject_flag);
+    bdrv_co_eject(bs->file->bs, eject_flag);
 }
 
 
@@ -258,7 +258,7 @@ static BlockDriver bdrv_copy_on_read = {
     .bdrv_co_pdiscard                   = cor_co_pdiscard,
     .bdrv_co_pwritev_compressed         = cor_co_pwritev_compressed,
 
-    .bdrv_eject                         = cor_eject,
+    .bdrv_co_eject                      = cor_co_eject,
     .bdrv_lock_medium                   = cor_lock_medium,
 
     .has_variable_length                = true,

block/file-posix.c

@@ -3765,7 +3765,7 @@ static bool coroutine_fn cdrom_co_is_inserted(BlockDriverState *bs)
     return ret == CDS_DISC_OK;
 }
 
-static void cdrom_eject(BlockDriverState *bs, bool eject_flag)
+static void coroutine_fn cdrom_co_eject(BlockDriverState *bs, bool eject_flag)
 {
     BDRVRawState *s = bs->opaque;
 
@@ -3823,7 +3823,7 @@ static BlockDriver bdrv_host_cdrom = {
 
     /* removable device support */
     .bdrv_co_is_inserted    = cdrom_co_is_inserted,
-    .bdrv_eject         = cdrom_eject,
+    .bdrv_co_eject          = cdrom_co_eject,
     .bdrv_lock_medium   = cdrom_lock_medium,
 
     /* generic scsi device */
@@ -3886,7 +3886,7 @@ static bool coroutine_fn cdrom_co_is_inserted(BlockDriverState *bs)
     return raw_co_getlength(bs) > 0;
 }
 
-static void cdrom_eject(BlockDriverState *bs, bool eject_flag)
+static void coroutine_fn cdrom_co_eject(BlockDriverState *bs, bool eject_flag)
 {
     BDRVRawState *s = bs->opaque;
 
@@ -3952,7 +3952,7 @@ static BlockDriver bdrv_host_cdrom = {
 
     /* removable device support */
     .bdrv_co_is_inserted     = cdrom_co_is_inserted,
-    .bdrv_eject         = cdrom_eject,
+    .bdrv_co_eject           = cdrom_co_eject,
     .bdrv_lock_medium   = cdrom_lock_medium,
 };
 #endif /* __FreeBSD__ */

block/filter-compress.c

@@ -117,9 +117,10 @@ static void compress_refresh_limits(BlockDriverState *bs, Error **errp)
 }
 
 
-static void compress_eject(BlockDriverState *bs, bool eject_flag)
+static void coroutine_fn
+compress_co_eject(BlockDriverState *bs, bool eject_flag)
 {
-    bdrv_eject(bs->file->bs, eject_flag);
+    bdrv_co_eject(bs->file->bs, eject_flag);
 }
 
 
@@ -143,7 +144,7 @@ static BlockDriver bdrv_compress = {
     .bdrv_co_pdiscard                   = compress_co_pdiscard,
     .bdrv_refresh_limits                = compress_refresh_limits,
 
-    .bdrv_eject                         = compress_eject,
+    .bdrv_co_eject                      = compress_co_eject,
     .bdrv_lock_medium                   = compress_lock_medium,
 
     .has_variable_length                = true,

block/raw-format.c

@@ -405,9 +405,9 @@ static int coroutine_fn raw_co_truncate(BlockDriverState *bs, int64_t offset,
     return bdrv_co_truncate(bs->file, offset, exact, prealloc, flags, errp);
 }
 
-static void raw_eject(BlockDriverState *bs, bool eject_flag)
+static void coroutine_fn raw_co_eject(BlockDriverState *bs, bool eject_flag)
 {
-    bdrv_eject(bs->file->bs, eject_flag);
+    bdrv_co_eject(bs->file->bs, eject_flag);
 }
 
 static void raw_lock_medium(BlockDriverState *bs, bool locked)
@@ -631,7 +631,7 @@ BlockDriver bdrv_raw = {
     .bdrv_refresh_limits  = &raw_refresh_limits,
     .bdrv_probe_blocksizes = &raw_probe_blocksizes,
     .bdrv_probe_geometry  = &raw_probe_geometry,
-    .bdrv_eject           = &raw_eject,
+    .bdrv_co_eject        = &raw_co_eject,
     .bdrv_lock_medium     = &raw_lock_medium,
     .bdrv_co_ioctl        = &raw_co_ioctl,
     .create_opts          = &raw_create_opts,

include/block/block-io.h

@@ -147,7 +147,8 @@ bool coroutine_fn bdrv_co_is_inserted(BlockDriverState *bs);
 bool co_wrapper bdrv_is_inserted(BlockDriverState *bs);
 
 void bdrv_lock_medium(BlockDriverState *bs, bool locked);
-void bdrv_eject(BlockDriverState *bs, bool eject_flag);
+void coroutine_fn bdrv_co_eject(BlockDriverState *bs, bool eject_flag);
+
 const char *bdrv_get_format_name(BlockDriverState *bs);
 
 bool bdrv_supports_compressed_writes(BlockDriverState *bs);

include/block/block_int-common.h

@@ -708,7 +708,7 @@ struct BlockDriver {
 
     /* removable device specific */
     bool coroutine_fn (*bdrv_co_is_inserted)(BlockDriverState *bs);
-    void (*bdrv_eject)(BlockDriverState *bs, bool eject_flag);
+    void coroutine_fn (*bdrv_co_eject)(BlockDriverState *bs, bool eject_flag);
     void (*bdrv_lock_medium)(BlockDriverState *bs, bool locked);
 
     /* to control generic scsi devices */

include/sysemu/block-backend-io.h

@@ -60,7 +60,9 @@ bool co_wrapper_mixed blk_is_inserted(BlockBackend *blk);
 
 bool blk_is_available(BlockBackend *blk);
 void blk_lock_medium(BlockBackend *blk, bool locked);
-void blk_eject(BlockBackend *blk, bool eject_flag);
+
+void coroutine_fn blk_co_eject(BlockBackend *blk, bool eject_flag);
+void co_wrapper blk_eject(BlockBackend *blk, bool eject_flag);
 
 int64_t coroutine_fn blk_co_getlength(BlockBackend *blk);
 int64_t co_wrapper_mixed blk_getlength(BlockBackend *blk);