From 205ef7961f781496366e0a93a4ec621ad3724bd7 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 21 Oct 2010 16:43:43 +0200 Subject: [PATCH] block: Allow bdrv_flush to return errors This changes bdrv_flush to return 0 on success and -errno in case of failure. It's a requirement for implementing proper error handle in users of bdrv_flush. Signed-off-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi --- block.c | 21 +++++++++++++++++---- block.h | 2 +- block/blkdebug.c | 4 ++-- block/blkverify.c | 4 ++-- block/cow.c | 4 ++-- block/qcow.c | 4 ++-- block/qcow2.c | 4 ++-- block/raw-posix.c | 4 ++-- block/raw-win32.c | 9 ++++++++- block/raw.c | 4 ++-- block/vdi.c | 4 ++-- block/vmdk.c | 4 ++-- block_int.h | 2 +- 13 files changed, 45 insertions(+), 25 deletions(-) diff --git a/block.c b/block.c index 985d0b7e3..6b505fba1 100644 --- a/block.c +++ b/block.c @@ -1453,14 +1453,27 @@ const char *bdrv_get_device_name(BlockDriverState *bs) return bs->device_name; } -void bdrv_flush(BlockDriverState *bs) +int bdrv_flush(BlockDriverState *bs) { if (bs->open_flags & BDRV_O_NO_FLUSH) { - return; + return 0; + } + + if (bs->drv && bs->drv->bdrv_flush) { + return bs->drv->bdrv_flush(bs); } - if (bs->drv && bs->drv->bdrv_flush) - bs->drv->bdrv_flush(bs); + /* + * Some block drivers always operate in either writethrough or unsafe mode + * and don't support bdrv_flush therefore. Usually qemu doesn't know how + * the server works (because the behaviour is hardcoded or depends on + * server-side configuration), so we can't ensure that everything is safe + * on disk. Returning an error doesn't work because that would break guests + * even if the server operates in writethrough mode. + * + * Let's hope the user knows what he's doing. + */ + return 0; } void bdrv_flush_all(void) diff --git a/block.h b/block.h index a4facf2fa..78ecfac34 100644 --- a/block.h +++ b/block.h @@ -142,7 +142,7 @@ BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs, BlockDriverCompletionFunc *cb, void *opaque); /* Ensure contents are flushed to disk. */ -void bdrv_flush(BlockDriverState *bs); +int bdrv_flush(BlockDriverState *bs); void bdrv_flush_all(void); void bdrv_close_all(void); diff --git a/block/blkdebug.c b/block/blkdebug.c index 4d6ff0a36..cd9eb8006 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -397,9 +397,9 @@ static void blkdebug_close(BlockDriverState *bs) } } -static void blkdebug_flush(BlockDriverState *bs) +static int blkdebug_flush(BlockDriverState *bs) { - bdrv_flush(bs->file); + return bdrv_flush(bs->file); } static BlockDriverAIOCB *blkdebug_aio_flush(BlockDriverState *bs, diff --git a/block/blkverify.c b/block/blkverify.c index b2a12fe7f..0a8d69121 100644 --- a/block/blkverify.c +++ b/block/blkverify.c @@ -116,12 +116,12 @@ static void blkverify_close(BlockDriverState *bs) s->test_file = NULL; } -static void blkverify_flush(BlockDriverState *bs) +static int blkverify_flush(BlockDriverState *bs) { BDRVBlkverifyState *s = bs->opaque; /* Only flush test file, the raw file is not important */ - bdrv_flush(s->test_file); + return bdrv_flush(s->test_file); } static int64_t blkverify_getlength(BlockDriverState *bs) diff --git a/block/cow.c b/block/cow.c index eedcc4877..4cf543c83 100644 --- a/block/cow.c +++ b/block/cow.c @@ -282,9 +282,9 @@ exit: return ret; } -static void cow_flush(BlockDriverState *bs) +static int cow_flush(BlockDriverState *bs) { - bdrv_flush(bs->file); + return bdrv_flush(bs->file); } static QEMUOptionParameter cow_create_options[] = { diff --git a/block/qcow.c b/block/qcow.c index 816103d39..9cd547dc0 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -910,9 +910,9 @@ static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, return 0; } -static void qcow_flush(BlockDriverState *bs) +static int qcow_flush(BlockDriverState *bs) { - bdrv_flush(bs->file); + return bdrv_flush(bs->file); } static BlockDriverAIOCB *qcow_aio_flush(BlockDriverState *bs, diff --git a/block/qcow2.c b/block/qcow2.c index b816d8733..537c479a7 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1148,9 +1148,9 @@ static int qcow_write_compressed(BlockDriverState *bs, int64_t sector_num, return 0; } -static void qcow_flush(BlockDriverState *bs) +static int qcow_flush(BlockDriverState *bs) { - bdrv_flush(bs->file); + return bdrv_flush(bs->file); } static BlockDriverAIOCB *qcow_aio_flush(BlockDriverState *bs, diff --git a/block/raw-posix.c b/block/raw-posix.c index d0393e0c4..d0960b85c 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -734,10 +734,10 @@ static int raw_create(const char *filename, QEMUOptionParameter *options) return result; } -static void raw_flush(BlockDriverState *bs) +static int raw_flush(BlockDriverState *bs) { BDRVRawState *s = bs->opaque; - qemu_fdatasync(s->fd); + return qemu_fdatasync(s->fd); } diff --git a/block/raw-win32.c b/block/raw-win32.c index 503ed3959..7f3277861 100644 --- a/block/raw-win32.c +++ b/block/raw-win32.c @@ -150,7 +150,14 @@ static int raw_write(BlockDriverState *bs, int64_t sector_num, static void raw_flush(BlockDriverState *bs) { BDRVRawState *s = bs->opaque; - FlushFileBuffers(s->hfile); + int ret; + + ret = FlushFileBuffers(s->hfile); + if (ret != 0) { + return -EIO; + } + + return 0; } static void raw_close(BlockDriverState *bs) diff --git a/block/raw.c b/block/raw.c index 91087792f..1980debc0 100644 --- a/block/raw.c +++ b/block/raw.c @@ -39,9 +39,9 @@ static void raw_close(BlockDriverState *bs) { } -static void raw_flush(BlockDriverState *bs) +static int raw_flush(BlockDriverState *bs) { - bdrv_flush(bs->file); + return bdrv_flush(bs->file); } static BlockDriverAIOCB *raw_aio_flush(BlockDriverState *bs, diff --git a/block/vdi.c b/block/vdi.c index f72633cf1..3b51e532c 100644 --- a/block/vdi.c +++ b/block/vdi.c @@ -900,10 +900,10 @@ static void vdi_close(BlockDriverState *bs) { } -static void vdi_flush(BlockDriverState *bs) +static int vdi_flush(BlockDriverState *bs) { logout("\n"); - bdrv_flush(bs->file); + return bdrv_flush(bs->file); } diff --git a/block/vmdk.c b/block/vmdk.c index 2d4ba421d..872aebac9 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -823,9 +823,9 @@ static void vmdk_close(BlockDriverState *bs) qemu_free(s->l2_cache); } -static void vmdk_flush(BlockDriverState *bs) +static int vmdk_flush(BlockDriverState *bs) { - bdrv_flush(bs->file); + return bdrv_flush(bs->file); } diff --git a/block_int.h b/block_int.h index 87e60b859..3c3adb5c8 100644 --- a/block_int.h +++ b/block_int.h @@ -59,7 +59,7 @@ struct BlockDriver { const uint8_t *buf, int nb_sectors); void (*bdrv_close)(BlockDriverState *bs); int (*bdrv_create)(const char *filename, QEMUOptionParameter *options); - void (*bdrv_flush)(BlockDriverState *bs); + int (*bdrv_flush)(BlockDriverState *bs); int (*bdrv_is_allocated)(BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum); int (*bdrv_set_key)(BlockDriverState *bs, const char *key); -- 2.39.5