diff options
| -rw-r--r-- | block/file-posix.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/block/file-posix.c b/block/file-posix.c index 3794c0007a..3707ea2d1c 100644 --- a/block/file-posix.c +++ b/block/file-posix.c @@ -2236,6 +2236,49 @@ static int coroutine_fn raw_co_block_status(BlockDriverState *bs, return ret | BDRV_BLOCK_OFFSET_VALID; } +static void coroutine_fn raw_co_invalidate_cache(BlockDriverState *bs, + Error **errp) +{ + BDRVRawState *s = bs->opaque; + int ret; + + ret = fd_open(bs); + if (ret < 0) { + error_setg_errno(errp, -ret, "The file descriptor is not open"); + return; + } + + if (s->open_flags & O_DIRECT) { + return; /* No host kernel page cache */ + } + +#if defined(__linux__) + /* This sets the scene for the next syscall... */ + ret = bdrv_co_flush(bs); + if (ret < 0) { + error_setg_errno(errp, -ret, "flush failed"); + return; + } + + /* Linux does not invalidate pages that are dirty, locked, or mmapped by a + * process. These limitations are okay because we just fsynced the file, + * we don't use mmap, and the file should not be in use by other processes. + */ + ret = posix_fadvise(s->fd, 0, 0, POSIX_FADV_DONTNEED); + if (ret != 0) { /* the return value is a positive errno */ + error_setg_errno(errp, ret, "fadvise failed"); + return; + } +#else /* __linux__ */ + /* Do nothing. Live migration to a remote host with cache.direct=off is + * unsupported on other host operating systems. Cache consistency issues + * may occur but no error is reported here, partly because that's the + * historical behavior and partly because it's hard to differentiate valid + * configurations that should not cause errors. + */ +#endif /* !__linux__ */ +} + static coroutine_fn BlockAIOCB *raw_aio_pdiscard(BlockDriverState *bs, int64_t offset, int bytes, BlockCompletionFunc *cb, void *opaque) @@ -2328,6 +2371,7 @@ BlockDriver bdrv_file = { .bdrv_co_create_opts = raw_co_create_opts, .bdrv_has_zero_init = bdrv_has_zero_init_1, .bdrv_co_block_status = raw_co_block_status, + .bdrv_co_invalidate_cache = raw_co_invalidate_cache, .bdrv_co_pwrite_zeroes = raw_co_pwrite_zeroes, .bdrv_co_preadv = raw_co_preadv, @@ -2805,6 +2849,7 @@ static BlockDriver bdrv_host_device = { .bdrv_reopen_abort = raw_reopen_abort, .bdrv_co_create_opts = hdev_co_create_opts, .create_opts = &raw_create_opts, + .bdrv_co_invalidate_cache = raw_co_invalidate_cache, .bdrv_co_pwrite_zeroes = hdev_co_pwrite_zeroes, .bdrv_co_preadv = raw_co_preadv, @@ -2927,6 +2972,7 @@ static BlockDriver bdrv_host_cdrom = { .bdrv_reopen_abort = raw_reopen_abort, .bdrv_co_create_opts = hdev_co_create_opts, .create_opts = &raw_create_opts, + .bdrv_co_invalidate_cache = raw_co_invalidate_cache, .bdrv_co_preadv = raw_co_preadv, |