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| author | Jens Axboe <axboe@kernel.dk> | 2019-12-26 00:33:42 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-01-21 01:03:59 +0100 |
| commit | ba04291eb66ed895f194ae5abd3748d72bf8aaea (patch) | |
| tree | 398b8455348b4b2a2171554f01447c74ffb9f28e /include | |
| parent | io_uring: add non-vectored read/write commands (diff) | |
| download | linux-ba04291eb66ed895f194ae5abd3748d72bf8aaea.tar.xz linux-ba04291eb66ed895f194ae5abd3748d72bf8aaea.zip | |
io_uring: allow use of offset == -1 to mean file position
This behaves like preadv2/pwritev2 with offset == -1, it'll use (and
update) the current file position. This obviously comes with the caveat
that if the application has multiple read/writes in flight, then the
end result will not be as expected. This is similar to threads sharing
a file descriptor and doing IO using the current file position.
Since this feature isn't easily detectable by doing a read or write,
add a feature flags, IORING_FEAT_RW_CUR_POS, to allow applications to
detect presence of this feature.
Reported-by: 李通洲 <carter.li@eoitek.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'include')
| -rw-r--r-- | include/uapi/linux/io_uring.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index 7fdf994f3313..1f96136eb6ee 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -174,6 +174,7 @@ struct io_uring_params { #define IORING_FEAT_SINGLE_MMAP (1U << 0) #define IORING_FEAT_NODROP (1U << 1) #define IORING_FEAT_SUBMIT_STABLE (1U << 2) +#define IORING_FEAT_RW_CUR_POS (1U << 3) /* * io_uring_register(2) opcodes and arguments |