| Message ID | 20220607233143.1168114-2-viro@zeniv.linux.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [01/10] No need of likely/unlikely on calls of check_copy_size() | expand |
Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
On Tue, Jun 07, 2022 at 11:31:35PM +0000, Al Viro wrote: > New flag, equivalent to removal of IOCB_DSYNC from iocb flags. > This mimics what btrfs is doing (and that's what btrfs will > switch to). However, I'm not at all sure that we want to > suppress REQ_FUA for those - all btrfs hack really cares about > is suppression of generic_write_sync(). For now let's keep > the existing behaviour, but I really want to hear more detailed > arguments pro or contra. > > [folded brain fix from willy] > > Suggested-by: Christoph Hellwig <hch@lst.de> > Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Looks ok, Reviewed-by: Darrick J. Wong <djwong@kernel.org> --D > --- > fs/iomap/direct-io.c | 20 +++++++++++--------- > include/linux/iomap.h | 6 ++++++ > 2 files changed, 17 insertions(+), 9 deletions(-) > > diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c > index 370c3241618a..c10c69e2de24 100644 > --- a/fs/iomap/direct-io.c > +++ b/fs/iomap/direct-io.c > @@ -548,17 +548,19 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, > } > > /* for data sync or sync, we need sync completion processing */ > - if (iocb->ki_flags & IOCB_DSYNC) > + if (iocb->ki_flags & IOCB_DSYNC && > + !(dio_flags & IOMAP_DIO_NOSYNC)) { > dio->flags |= IOMAP_DIO_NEED_SYNC; > > - /* > - * For datasync only writes, we optimistically try using FUA for > - * this IO. Any non-FUA write that occurs will clear this flag, > - * hence we know before completion whether a cache flush is > - * necessary. > - */ > - if ((iocb->ki_flags & (IOCB_DSYNC | IOCB_SYNC)) == IOCB_DSYNC) > - dio->flags |= IOMAP_DIO_WRITE_FUA; > + /* > + * For datasync only writes, we optimistically try > + * using FUA for this IO. Any non-FUA write that > + * occurs will clear this flag, hence we know before > + * completion whether a cache flush is necessary. > + */ > + if (!(iocb->ki_flags & IOCB_SYNC)) > + dio->flags |= IOMAP_DIO_WRITE_FUA; > + } > } > > if (dio_flags & IOMAP_DIO_OVERWRITE_ONLY) { > diff --git a/include/linux/iomap.h b/include/linux/iomap.h > index e552097c67e0..c8622d8f064e 100644 > --- a/include/linux/iomap.h > +++ b/include/linux/iomap.h > @@ -353,6 +353,12 @@ struct iomap_dio_ops { > */ > #define IOMAP_DIO_PARTIAL (1 << 2) > > +/* > + * The caller will sync the write if needed; do not sync it within > + * iomap_dio_rw. Overrides IOMAP_DIO_FORCE_WAIT. > + */ > +#define IOMAP_DIO_NOSYNC (1 << 3) > + > ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, > const struct iomap_ops *ops, const struct iomap_dio_ops *dops, > unsigned int dio_flags, void *private, size_t done_before); > -- > 2.30.2 >
On Tue, Jun 07, 2022 at 11:31:35PM +0000, Al Viro wrote: > New flag, equivalent to removal of IOCB_DSYNC from iocb flags. > This mimics what btrfs is doing (and that's what btrfs will > switch to). However, I'm not at all sure that we want to > suppress REQ_FUA for those - all btrfs hack really cares about > is suppression of generic_write_sync(). For now let's keep > the existing behaviour, but I really want to hear more detailed > arguments pro or contra. > > [folded brain fix from willy] > > Suggested-by: Christoph Hellwig <hch@lst.de> > Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> > --- Looks good to me, Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index 370c3241618a..c10c69e2de24 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -548,17 +548,19 @@ __iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, } /* for data sync or sync, we need sync completion processing */ - if (iocb->ki_flags & IOCB_DSYNC) + if (iocb->ki_flags & IOCB_DSYNC && + !(dio_flags & IOMAP_DIO_NOSYNC)) { dio->flags |= IOMAP_DIO_NEED_SYNC; - /* - * For datasync only writes, we optimistically try using FUA for - * this IO. Any non-FUA write that occurs will clear this flag, - * hence we know before completion whether a cache flush is - * necessary. - */ - if ((iocb->ki_flags & (IOCB_DSYNC | IOCB_SYNC)) == IOCB_DSYNC) - dio->flags |= IOMAP_DIO_WRITE_FUA; + /* + * For datasync only writes, we optimistically try + * using FUA for this IO. Any non-FUA write that + * occurs will clear this flag, hence we know before + * completion whether a cache flush is necessary. + */ + if (!(iocb->ki_flags & IOCB_SYNC)) + dio->flags |= IOMAP_DIO_WRITE_FUA; + } } if (dio_flags & IOMAP_DIO_OVERWRITE_ONLY) { diff --git a/include/linux/iomap.h b/include/linux/iomap.h index e552097c67e0..c8622d8f064e 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -353,6 +353,12 @@ struct iomap_dio_ops { */ #define IOMAP_DIO_PARTIAL (1 << 2) +/* + * The caller will sync the write if needed; do not sync it within + * iomap_dio_rw. Overrides IOMAP_DIO_FORCE_WAIT. + */ +#define IOMAP_DIO_NOSYNC (1 << 3) + ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops, const struct iomap_dio_ops *dops, unsigned int dio_flags, void *private, size_t done_before);
New flag, equivalent to removal of IOCB_DSYNC from iocb flags. This mimics what btrfs is doing (and that's what btrfs will switch to). However, I'm not at all sure that we want to suppress REQ_FUA for those - all btrfs hack really cares about is suppression of generic_write_sync(). For now let's keep the existing behaviour, but I really want to hear more detailed arguments pro or contra. [folded brain fix from willy] Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> --- fs/iomap/direct-io.c | 20 +++++++++++--------- include/linux/iomap.h | 6 ++++++ 2 files changed, 17 insertions(+), 9 deletions(-)