diff options
| -rw-r--r-- | block/nfs.c | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/block/nfs.c b/block/nfs.c index 02eb4e4643..887a98e3fc 100644 --- a/block/nfs.c +++ b/block/nfs.c @@ -43,6 +43,7 @@ typedef struct NFSClient { int events; bool has_zero_init; AioContext *aio_context; + blkcnt_t st_blocks; } NFSClient; typedef struct NFSRPC { @@ -374,6 +375,7 @@ static int64_t nfs_client_open(NFSClient *client, const char *filename, } ret = DIV_ROUND_UP(st.st_size, BDRV_SECTOR_SIZE); + client->st_blocks = st.st_blocks; client->has_zero_init = S_ISREG(st.st_mode); goto out; fail: @@ -464,6 +466,11 @@ static int64_t nfs_get_allocated_file_size(BlockDriverState *bs) NFSRPC task = {0}; struct stat st; + if (bdrv_is_read_only(bs) && + !(bs->open_flags & BDRV_O_NOCACHE)) { + return client->st_blocks * 512; + } + task.st = &st; if (nfs_fstat_async(client->context, client->fh, nfs_co_generic_cb, &task) != 0) { @@ -484,6 +491,34 @@ static int nfs_file_truncate(BlockDriverState *bs, int64_t offset) return nfs_ftruncate(client->context, client->fh, offset); } +/* Note that this will not re-establish a connection with the NFS server + * - it is effectively a NOP. */ +static int nfs_reopen_prepare(BDRVReopenState *state, + BlockReopenQueue *queue, Error **errp) +{ + NFSClient *client = state->bs->opaque; + struct stat st; + int ret = 0; + + if (state->flags & BDRV_O_RDWR && bdrv_is_read_only(state->bs)) { + error_setg(errp, "Cannot open a read-only mount as read-write"); + return -EACCES; + } + + /* Update cache for read-only reopens */ + if (!(state->flags & BDRV_O_RDWR)) { + ret = nfs_fstat(client->context, client->fh, &st); + if (ret < 0) { + error_setg(errp, "Failed to fstat file: %s", + nfs_get_error(client->context)); + return ret; + } + client->st_blocks = st.st_blocks; + } + + return 0; +} + static BlockDriver bdrv_nfs = { .format_name = "nfs", .protocol_name = "nfs", @@ -499,6 +534,7 @@ static BlockDriver bdrv_nfs = { .bdrv_file_open = nfs_file_open, .bdrv_close = nfs_file_close, .bdrv_create = nfs_file_create, + .bdrv_reopen_prepare = nfs_reopen_prepare, .bdrv_co_readv = nfs_co_readv, .bdrv_co_writev = nfs_co_writev, |