On 05/02/2024 15:20, Pankaj Raghav (Samsung) wrote:
On Wed, Jan 24, 2024 at 02:26:40PM +0000, John Garry wrote:Add flag IOMAP_ATOMIC_WRITE to indicate to the FS that an atomic write bio is being created and all the rules there need to be followed. It is the task of the FS iomap iter callbacks to ensure that the mapping created adheres to those rules, like size is power-of-2, is at a naturally-aligned offset, etc. However, checking for a single iovec, i.e. iter type is ubuf, is done in __iomap_dio_rw(). A write should only produce a single bio, so error when it doesn't. Signed-off-by: John Garry <john.g.garry@xxxxxxxxxx> --- fs/iomap/direct-io.c | 21 ++++++++++++++++++++- fs/iomap/trace.h | 3 ++- include/linux/iomap.h | 1 + 3 files changed, 23 insertions(+), 2 deletions(-) diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index bcd3f8cf5ea4..25736d01b857 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -275,10 +275,12 @@ static inline blk_opf_t iomap_dio_bio_opflags(struct iomap_dio *dio, static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter, struct iomap_dio *dio) { + bool atomic_write = iter->flags & IOMAP_ATOMIC;Minor nit: the commit says IOMAP_ATOMIC_WRITE and you set the enum as IOMAP_ATOMIC in the code.
Thanks for spotting this
As the atomic semantics only apply to write, the commit could be just reworded to reflect the code?
Yes, so I was advised to change IOMAP_ATOMIC_WRITE -> IOMAP_ATOMIC, as this flag is just a write modifier. I just didn't update the commit message.
Thanks, John
<snip>diff --git a/fs/iomap/trace.h b/fs/iomap/trace.h index c16fd55f5595..c95576420bca 100644 --- a/fs/iomap/trace.h +++ b/fs/iomap/trace.h @@ -98,7 +98,8 @@ DEFINE_RANGE_EVENT(iomap_dio_rw_queued); { IOMAP_REPORT, "REPORT" }, \ { IOMAP_FAULT, "FAULT" }, \ { IOMAP_DIRECT, "DIRECT" }, \ - { IOMAP_NOWAIT, "NOWAIT" } + { IOMAP_NOWAIT, "NOWAIT" }, \ + { IOMAP_ATOMIC, "ATOMIC" }
