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| author | Al Viro <viro@zeniv.linux.org.uk> | 2022-06-07 16:04:03 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2022-06-10 16:03:35 -0400 |
| commit | 36518b6b4da7e8d4387bc19ad21e772f1060e9d7 (patch) | |
| tree | b091764545f997c76f720f13914f2b171d9737e4 /fs/iomap/direct-io.c | |
| parent | 0e3c3b901c00364198d31482fa2552ccf2d5c899 (diff) | |
| download | linux-36518b6b4da7e8d4387bc19ad21e772f1060e9d7.tar.gz | |
teach iomap_dio_rw() to suppress dsync
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> Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/iomap/direct-io.c')
| -rw-r--r-- | fs/iomap/direct-io.c | 20 |
1 files changed, 11 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) { |