Return-Path: linux-nfs-owner@vger.kernel.org Received: from cobra.newdream.net ([66.33.216.30]:46537 "EHLO cobra.newdream.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752064AbaKJQH7 (ORCPT ); Mon, 10 Nov 2014 11:07:59 -0500 Date: Mon, 10 Nov 2014 08:07:58 -0800 (PST) From: Sage Weil To: Milosz Tanski cc: linux-kernel@vger.kernel.org, Christoph Hellwig , Christoph Hellwig , linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, Mel Gorman , Volker Lendecke , Tejun Heo , Jeff Moyer , "Theodore Ts'o" , Al Viro , linux-api@vger.kernel.org, Michael Kerrisk , linux-arch@vger.kernel.org, ceph-devel@vger.kernel.org, fuse-devel@lists.sourceforge.net, linux-nfs@vger.kernel.org, ocfs2-devel@oss.oracle.com, linux-mm@kvack.org Subject: Re: [PATCH v5 7/7] fs: add a flag for per-operation O_DSYNC semantics In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, 5 Nov 2014, Milosz Tanski wrote: > From: Christoph Hellwig > > With the new read/write with flags syscalls we can support a flag > to enable O_DSYNC semantics on a per-operation basis. This ?s > useful to implement protocols like SMB, NFS or SCSI that have such > per-operation flags. > > Example program below: > > cat > pwritev2.c << EOF > > (off_t) val, \ > (off_t) ((((uint64_t) (val)) >> (sizeof (long) * 4)) >> (sizeof (long) * 4)) > > static ssize_t > pwritev2(int fd, const struct iovec *iov, int iovcnt, off_t offset, int flags) > { > return syscall(__NR_pwritev2, fd, iov, iovcnt, LO_HI_LONG(offset), > flags); > } > > int main(int argc, char **argv) > { > int fd = open(argv[1], O_WRONLY|O_CREAT|O_TRUNC, 0666); > char buf[1024]; > struct iovec iov = { .iov_base = buf, .iov_len = 1024 }; > int ret; > > if (fd < 0) { > perror("open"); > return 0; > } > > memset(buf, 0xfe, sizeof(buf)); > > ret = pwritev2(fd, &iov, 1, 0, RWF_DSYNC); > if (ret < 0) > perror("pwritev2"); > else > printf("ret = %d\n", ret); > > return 0; > } > EOF > > Signed-off-by: Christoph Hellwig > [milosz@adfin.com: added flag check to compat_do_readv_writev()] > Signed-off-by: Milosz Tanski Ceph bits Acked-by: Sage Weil > --- > fs/ceph/file.c | 4 +++- > fs/fuse/file.c | 2 ++ > fs/nfs/file.c | 10 ++++++---- > fs/ocfs2/file.c | 6 ++++-- > fs/read_write.c | 20 +++++++++++++++----- > include/linux/fs.h | 3 ++- > mm/filemap.c | 4 +++- > 7 files changed, 35 insertions(+), 14 deletions(-) > > diff --git a/fs/ceph/file.c b/fs/ceph/file.c > index b798b5c..2d4e15a 100644 > --- a/fs/ceph/file.c > +++ b/fs/ceph/file.c > @@ -983,7 +983,9 @@ retry_snap: > ceph_put_cap_refs(ci, got); > > if (written >= 0 && > - ((file->f_flags & O_SYNC) || IS_SYNC(file->f_mapping->host) || > + ((file->f_flags & O_SYNC) || > + IS_SYNC(file->f_mapping->host) || > + (iocb->ki_rwflags & RWF_DSYNC) || > ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_NEARFULL))) { > err = vfs_fsync_range(file, pos, pos + written - 1, 1); > if (err < 0) > diff --git a/fs/fuse/file.c b/fs/fuse/file.c > index caa8d95..bb4fb23 100644 > --- a/fs/fuse/file.c > +++ b/fs/fuse/file.c > @@ -1248,6 +1248,8 @@ static ssize_t fuse_file_write_iter(struct kiocb *iocb, struct iov_iter *from) > written += written_buffered; > iocb->ki_pos = pos + written_buffered; > } else { > + if (iocb->ki_rwflags & RWF_DSYNC) > + return -EINVAL; > written = fuse_perform_write(file, mapping, from, pos); > if (written >= 0) > iocb->ki_pos = pos + written; > diff --git a/fs/nfs/file.c b/fs/nfs/file.c > index aa9046f..c59b0b7 100644 > --- a/fs/nfs/file.c > +++ b/fs/nfs/file.c > @@ -652,13 +652,15 @@ static const struct vm_operations_struct nfs_file_vm_ops = { > .remap_pages = generic_file_remap_pages, > }; > > -static int nfs_need_sync_write(struct file *filp, struct inode *inode) > +static int nfs_need_sync_write(struct kiocb *iocb, struct inode *inode) > { > struct nfs_open_context *ctx; > > - if (IS_SYNC(inode) || (filp->f_flags & O_DSYNC)) > + if (IS_SYNC(inode) || > + (iocb->ki_filp->f_flags & O_DSYNC) || > + (iocb->ki_rwflags & RWF_DSYNC)) > return 1; > - ctx = nfs_file_open_context(filp); > + ctx = nfs_file_open_context(iocb->ki_filp); > if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags) || > nfs_ctx_key_to_expire(ctx)) > return 1; > @@ -705,7 +707,7 @@ ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from) > written = result; > > /* Return error values for O_DSYNC and IS_SYNC() */ > - if (result >= 0 && nfs_need_sync_write(file, inode)) { > + if (result >= 0 && nfs_need_sync_write(iocb, inode)) { > int err = vfs_fsync(file, 0); > if (err < 0) > result = err; > diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c > index bb66ca4..8f9a86b 100644 > --- a/fs/ocfs2/file.c > +++ b/fs/ocfs2/file.c > @@ -2374,8 +2374,10 @@ out_dio: > /* buffered aio wouldn't have proper lock coverage today */ > BUG_ON(ret == -EIOCBQUEUED && !(file->f_flags & O_DIRECT)); > > - if (((file->f_flags & O_DSYNC) && !direct_io) || IS_SYNC(inode) || > - ((file->f_flags & O_DIRECT) && !direct_io)) { > + if (((file->f_flags & O_DSYNC) && !direct_io) || > + IS_SYNC(inode) || > + ((file->f_flags & O_DIRECT) && !direct_io) || > + (iocb->ki_rwflags & RWF_DSYNC)) { > ret = filemap_fdatawrite_range(file->f_mapping, *ppos, > *ppos + count - 1); > if (ret < 0) > diff --git a/fs/read_write.c b/fs/read_write.c > index cba7d4c..3443265 100644 > --- a/fs/read_write.c > +++ b/fs/read_write.c > @@ -839,8 +839,13 @@ static ssize_t do_readv_writev(int type, struct file *file, > ret = do_iter_readv_writev(file, type, iov, nr_segs, tot_len, > pos, iter_fn, flags); > } else { > - if (type == READ && (flags & RWF_NONBLOCK)) > - return -EAGAIN; > + if (type == READ) { > + if (flags & RWF_NONBLOCK) > + return -EAGAIN; > + } else { > + if (flags & RWF_DSYNC) > + return -EINVAL; > + } > > if (fnv) > ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, > @@ -888,7 +893,7 @@ ssize_t vfs_writev(struct file *file, const struct iovec __user *vec, > return -EBADF; > if (!(file->f_mode & FMODE_CAN_WRITE)) > return -EINVAL; > - if (flags & ~0) > + if (flags & ~RWF_DSYNC) > return -EINVAL; > > return do_readv_writev(WRITE, file, vec, vlen, pos, flags); > @@ -1080,8 +1085,13 @@ static ssize_t compat_do_readv_writev(int type, struct file *file, > ret = do_iter_readv_writev(file, type, iov, nr_segs, tot_len, > pos, iter_fn, flags); > } else { > - if (type == READ && (flags & RWF_NONBLOCK)) > - return -EAGAIN; > + if (type == READ) { > + if (flags & RWF_NONBLOCK) > + return -EAGAIN; > + } else { > + if (flags & RWF_DSYNC) > + return -EINVAL; > + } > > if (fnv) > ret = do_sync_readv_writev(file, iov, nr_segs, tot_len, > diff --git a/include/linux/fs.h b/include/linux/fs.h > index 7d0e116..7786b88 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -1460,7 +1460,8 @@ struct block_device_operations; > #define HAVE_UNLOCKED_IOCTL 1 > > /* These flags are used for the readv/writev syscalls with flags. */ > -#define RWF_NONBLOCK 0x00000001 > +#define RWF_NONBLOCK 0x00000001 > +#define RWF_DSYNC 0x00000002 > > struct iov_iter; > > diff --git a/mm/filemap.c b/mm/filemap.c > index 6107058..4fbef99 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -2669,7 +2669,9 @@ int generic_write_sync(struct kiocb *iocb, loff_t count) > struct file *file = iocb->ki_filp; > > if (count > 0 && > - ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host))) { > + ((file->f_flags & O_DSYNC) || > + (iocb->ki_rwflags & RWF_DSYNC) || > + IS_SYNC(file->f_mapping->host))) { > bool fdatasync = !(file->f_flags & __O_SYNC); > ssize_t ret = 0; > > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > >