| Message ID | 20250501181623.2942698-1-hch@lst.de |
|---|---|
| State | Superseded |
| Headers | show |
| Series | scsi: remove the stream_status member from scsi_stream_status_header | expand |
On Sat, May 03, 2025 at 12:05:46PM -0700, Bart Van Assche wrote: > There is an implicit assumption behind this patch, namely that the compiler > does not insert padding bytes between struct > scsi_stream_status_header and struct scsi_stream_status. Shouldn't this be > made explicit with a BUILD_BUG_ON() expression? We make that assumption for all our naturally alignend structures in every on-disk and on the wire structure.
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 950d8c9fb884..3f6e87705b62 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -3215,7 +3215,7 @@ static bool sd_is_perm_stream(struct scsi_disk *sdkp, unsigned int stream_id) return false; if (get_unaligned_be32(&buf.h.len) < sizeof(struct scsi_stream_status)) return false; - return buf.h.stream_status[0].perm; + return buf.s.perm; } static void sd_read_io_hints(struct scsi_disk *sdkp, unsigned char *buffer) diff --git a/include/scsi/scsi_proto.h b/include/scsi/scsi_proto.h index aeca37816506..bc8f2b2226be 100644 --- a/include/scsi/scsi_proto.h +++ b/include/scsi/scsi_proto.h @@ -349,7 +349,6 @@ struct scsi_stream_status_header { __be32 len; /* length in bytes of stream_status[] array. */ u16 reserved; __be16 number_of_open_streams; - DECLARE_FLEX_ARRAY(struct scsi_stream_status, stream_status); }; static_assert(sizeof(struct scsi_stream_status_header) == 8);
Having a variable length array at the end of scsi_stream_status_header only cause problems. Remove it and switch the one place that actually used it to use the struct member directly following in the actual on-disk structure instead. Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/scsi/sd.c | 2 +- include/scsi/scsi_proto.h | 1 - 2 files changed, 1 insertion(+), 2 deletions(-)