On 9/29/23 02:37, John Garry wrote:
+.BR RWF_ATOMIC " (since Linux 6.7)" +Allows block-based filesystems to indicate that write operations will be issued +with torn-write protection. Torn-write protection means that for a power or any +other hardware failure, all or none of the data from the write will be stored, +but never a mix of old and new data. This flag is meaningful only for +.BR pwritev2 (), +and its effect applies only to the data range written by the system call. +The total write length must be power-of-2 and must be sized between +stx_atomic_write_unit_min and stx_atomic_write_unit_max, both inclusive. The +write must be at a natural offset within the file with respect to the total +write length. Torn-write protection only works with +.B O_DIRECT +flag, i.e. buffered writes are not supported. To guarantee consistency from +the write between a file's in-core state with the storage device,
It seems wrong to me to start the first sentence with "Allows". Atomic behavior should be mandatory if RWF_ATOMIC has been set. Additionally, shouldn't it be documented what value will be stored in errno if the atomic write has been rejected? Thanks, Bart.
