From ecc33845ca78a6420a86126cc18b765d03ec622f Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Tue, 18 Jan 2011 16:03:14 -0200 Subject: [PATCH 05/24] block: Allow bdrv_flush to return errors RH-Author: Kevin Wolf Message-id: <1295366596-3551-5-git-send-email-kwolf@redhat.com> Patchwork-id: 16503 O-Subject: [RHEL-6.1 qemu-kvm PATCH 4/6] block: Allow bdrv_flush to return errors Bugzilla: 670539 RH-Acked-by: Juan Quintela RH-Acked-by: Alex Williamson RH-Acked-by: Jes Sorensen Bugzilla: 670539 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 (cherry picked from commit 205ef7961f781496366e0a93a4ec621ad3724bd7) Conflicts: block.c block/blkverify.c block/cow.c block/vmdk.c --- block.c | 21 +++++++++++++++++---- block.h | 2 +- block/blkdebug.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 +- 12 files changed, 43 insertions(+), 23 deletions(-) Signed-off-by: Luiz Capitulino --- block.c | 21 +++++++++++++++++---- block.h | 2 +- block/blkdebug.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 +- 12 files changed, 43 insertions(+), 23 deletions(-) diff --git a/block.c b/block.c index bd53985..7541a72 100644 --- a/block.c +++ b/block.c @@ -1357,14 +1357,27 @@ 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 9b082c0..72e43a3 100644 --- a/block.h +++ b/block.h @@ -136,7 +136,7 @@ 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); int bdrv_has_zero_init(BlockDriverState *bs); diff --git a/block/blkdebug.c b/block/blkdebug.c index 7b7f87b..e36cd9e 100644 --- a/block/blkdebug.c +++ b/block/blkdebug.c @@ -392,9 +392,9 @@ 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/cow.c b/block/cow.c index fde066e..8e21f02 100644 --- a/block/cow.c +++ b/block/cow.c @@ -267,10 +267,10 @@ exit: return ret; } -static void cow_flush(BlockDriverState *bs) +static int cow_flush(BlockDriverState *bs) { BDRVCowState *s = bs->opaque; - qemu_fdatasync(s->fd); + return qemu_fdatasync(s->fd); } static QEMUOptionParameter cow_create_options[] = { diff --git a/block/qcow.c b/block/qcow.c index 1c0be6d..309c56e 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -907,9 +907,9 @@ 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 deea8f8..483607a 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -1250,9 +1250,9 @@ 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 915968a..a38ae91 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -720,10 +720,10 @@ 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 32ce701..5650389 100644 --- a/block/raw-win32.c +++ b/block/raw-win32.c @@ -154,7 +154,14 @@ 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 9108779..1980deb 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 314457b..1367ec8 100644 --- a/block/vdi.c +++ b/block/vdi.c @@ -882,10 +882,10 @@ 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 5ef4375..b92efdb 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -884,10 +884,10 @@ static void vmdk_close(BlockDriverState *bs) bdrv_delete(s->hd); } -static void vmdk_flush(BlockDriverState *bs) +static int vmdk_flush(BlockDriverState *bs) { BDRVVmdkState *s = bs->opaque; - bdrv_flush(s->hd); + return bdrv_flush(s->hd); } diff --git a/block_int.h b/block_int.h index 77ae5b2..e5873ae 100644 --- a/block_int.h +++ b/block_int.h @@ -58,7 +58,7 @@ 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); -- 1.7.4.rc1.16.gd2f15e