[PATCH v2] io_uring_enter(2): clarify OP_READ and OP_WRITE

[PATCH v2] io_uring_enter(2): clarify OP_READ and OP_WRITE

[Drew DeVault]

These do not advance the internal file offset unless the offset is set
to -1, making them behave more like pread/pwrite than read/write.
---
 man/io_uring_enter.2 | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/man/io_uring_enter.2 b/man/io_uring_enter.2
index f898ffd..5b498e5 100644
--- a/man/io_uring_enter.2
+++ b/man/io_uring_enter.2
@@ -576,16 +576,24 @@ for the general description of the related system call. Available since 5.6.
 .TP
 .B IORING_OP_WRITE
 Issue the equivalent of a
-.BR read(2)
+.BR pread(2)
 or
-.BR write(2)
+.BR pwrite(2)
 system call.
 .I fd
 is the file descriptor to be operated on,
 .I addr
-contains the buffer in question, and
+contains the buffer in question,
 .I len
-contains the length of the IO operation. These are non-vectored versions of the
+contains the length of the IO operation, and
+.I offs
+contains the read or write offset. If
+.I offs
+is set to -1, the offset will use (and advance) the file position, like the
+.BR read(2)
+and
+.BR write(2)
+system calls. These are non-vectored versions of the
 .B IORING_OP_READV
 and
 .B IORING_OP_WRITEV
-- 
2.31.1

Re: [PATCH v2] io_uring_enter(2): clarify OP_READ and OP_WRITE

[Jens Axboe]

On 5/23/21 10:44 AM, Drew DeVault wrote:
> These do not advance the internal file offset unless the offset is set
> to -1, making them behave more like pread/pwrite than read/write.

Applied, thanks.

-- 
Jens Axboe