On 01/10/2023 14:23, Bart Van Assche wrote:
On 9/29/23 15:49, Eric Biggers wrote:
On Fri, Sep 29, 2023 at 10:27:08AM +0000, John Garry wrote:
diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h
index 7cab2c65d3d7..c99d7cac2aa6 100644
--- a/include/uapi/linux/stat.h
+++ b/include/uapi/linux/stat.h
@@ -127,7 +127,10 @@ struct statx {
__u32 stx_dio_mem_align; /* Memory buffer alignment for
direct I/O */
__u32 stx_dio_offset_align; /* File offset alignment for
direct I/O */
/* 0xa0 */
- __u64 __spare3[12]; /* Spare space for future expansion */
+ __u32 stx_atomic_write_unit_max;
+ __u32 stx_atomic_write_unit_min;
Maybe min first and then max? That seems a bit more natural, and a
lot of the
code you've written handle them in that order.
ok, I think it's fine to reorder
+#define STATX_ATTR_WRITE_ATOMIC 0x00400000 /* File supports
atomic write operations */
How would this differ from stx_atomic_write_unit_min != 0?
Yeah, I suppose that we can just not set this for the case of
stx_atomic_write_unit_min == 0.
Is it even possible that stx_atomic_write_unit_min == 0? My understanding
is that all Linux filesystems rely on the assumption that writing a single
logical block either succeeds or does not happen, even if a power failure
occurs between writing and reading a logical block.
Maybe they do rely on this, but is it particularly interesting?
BTW, I would not like to provide assurances that every storage media
produced writes logical blocks atomically.
Thanks,
John
