Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-qa0-f46.google.com ([209.85.216.46]:54775 "EHLO mail-qa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751936AbaKEVPN (ORCPT ); Wed, 5 Nov 2014 16:15:13 -0500 Received: by mail-qa0-f46.google.com with SMTP id n8so1149740qaq.19 for ; Wed, 05 Nov 2014 13:15:12 -0800 (PST) From: Milosz Tanski To: linux-kernel@vger.kernel.org Cc: 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: [PATCH v5 7/7] fs: add a flag for per-operation O_DSYNC semantics Date: Wed, 5 Nov 2014 16:14:53 -0500 Message-Id: In-Reply-To: References: In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: 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 іs 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 --- 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