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| author | Alberto Faria <afaria@redhat.com> | 2022-10-29 13:20:31 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2022-10-31 14:33:15 -0400 |
| commit | 4c8f4fda0504564580f5c0a37e2d4b32ff17d2a1 (patch) | |
| tree | 57f53b90e5d542bd6644b7a003f1336ac255bafc | |
| parent | 03d9e4c0dba9d1b5d0c532ac3518415466ebdf8f (diff) | |
| download | qemu-4c8f4fda0504564580f5c0a37e2d4b32ff17d2a1.zip qemu-4c8f4fda0504564580f5c0a37e2d4b32ff17d2a1.tar.gz qemu-4c8f4fda0504564580f5c0a37e2d4b32ff17d2a1.tar.bz2 | |
block/blkio: Tolerate device size changes
Some libblkio drivers may be able to work with regular files (e.g.,
io_uring) or otherwise resizable devices. Conservatively set
BlockDriver::has_variable_length to true to ensure bdrv_nb_sectors()
always gives up-to-date results.
Also implement BlockDriver::bdrv_co_truncate for the case where no
preallocation is needed and the device already has a size compatible
with what was requested.
Signed-off-by: Alberto Faria <afaria@redhat.com>
Message-id: 20221029122031.975273-1-afaria@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
| -rw-r--r-- | block/blkio.c | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/block/blkio.c b/block/blkio.c index f55eb77..d850506 100644 --- a/block/blkio.c +++ b/block/blkio.c @@ -848,6 +848,31 @@ static int64_t blkio_getlength(BlockDriverState *bs) return capacity; } +static int coroutine_fn blkio_truncate(BlockDriverState *bs, int64_t offset, + bool exact, PreallocMode prealloc, + BdrvRequestFlags flags, Error **errp) +{ + int64_t current_length; + + if (prealloc != PREALLOC_MODE_OFF) { + error_setg(errp, "Unsupported preallocation mode '%s'", + PreallocMode_str(prealloc)); + return -ENOTSUP; + } + + current_length = blkio_getlength(bs); + + if (offset > current_length) { + error_setg(errp, "Cannot grow device"); + return -EINVAL; + } else if (exact && offset != current_length) { + error_setg(errp, "Cannot resize device"); + return -ENOTSUP; + } + + return 0; +} + static int blkio_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) { return 0; @@ -963,10 +988,12 @@ static void blkio_refresh_limits(BlockDriverState *bs, Error **errp) { \ .format_name = name, \ .protocol_name = name, \ + .has_variable_length = true, \ .instance_size = sizeof(BDRVBlkioState), \ .bdrv_file_open = blkio_file_open, \ .bdrv_close = blkio_close, \ .bdrv_getlength = blkio_getlength, \ + .bdrv_co_truncate = blkio_truncate, \ .bdrv_get_info = blkio_get_info, \ .bdrv_attach_aio_context = blkio_attach_aio_context, \ .bdrv_detach_aio_context = blkio_detach_aio_context, \ |