From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([65.50.211.133]:49757 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752093AbdB1O6E (ORCPT ); Tue, 28 Feb 2017 09:58:04 -0500 From: Christoph Hellwig Subject: [PATCH 05/12] fs: add a F_IOINFO fcntl Date: Tue, 28 Feb 2017 06:57:30 -0800 Message-Id: <20170228145737.19016-6-hch@lst.de> In-Reply-To: <20170228145737.19016-1-hch@lst.de> References: <20170228145737.19016-1-hch@lst.de> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-block@vger.kernel.org This fcntl can be used to query I/O parameters for the given file descriptor. Initially it is used for the I/O alignment and atomic write parameters. Signed-off-by: Christoph Hellwig --- fs/fcntl.c | 18 ++++++++++++++++++ include/linux/fs.h | 1 + include/uapi/linux/fcntl.h | 16 ++++++++++++++++ 3 files changed, 35 insertions(+) diff --git a/fs/fcntl.c b/fs/fcntl.c index ca5d228be7ea..248fb4cc66a6 100644 --- a/fs/fcntl.c +++ b/fs/fcntl.c @@ -241,6 +241,21 @@ static int f_getowner_uids(struct file *filp, unsigned long arg) } #endif +static int fcntl_ioinfo(struct file *file, void __user *argp) +{ + struct fcntl_ioinfo fio = { 0, }; + + if (file->f_op->ioinfo) { + int ret = file->f_op->ioinfo(file, &fio); + if (ret) + return ret; + } + + if (copy_to_user(argp, &fio, sizeof(fio))) + return -EFAULT; + return 0; +} + static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, struct file *filp) { @@ -335,6 +350,9 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, case F_GET_SEALS: err = shmem_fcntl(filp, cmd, arg); break; + case F_IOINFO: + err = fcntl_ioinfo(filp, (void __user *)arg); + break; default: break; } diff --git a/include/linux/fs.h b/include/linux/fs.h index 2ba074328894..33b08a8c2bc3 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1680,6 +1680,7 @@ struct file_operations { u64); ssize_t (*dedupe_file_range)(struct file *, u64, u64, struct file *, u64); + int (*ioinfo)(struct file *, struct fcntl_ioinfo *); }; struct inode_operations { diff --git a/include/uapi/linux/fcntl.h b/include/uapi/linux/fcntl.h index beed138bd359..6b0aaba7c623 100644 --- a/include/uapi/linux/fcntl.h +++ b/include/uapi/linux/fcntl.h @@ -42,6 +42,22 @@ #define F_SEAL_WRITE 0x0008 /* prevent writes */ /* (1U << 31) is reserved for signed error codes */ + +#define F_IOINFO (F_LINUX_SPECIFIC_BASE + 11) + +struct fcntl_ioinfo { + __u16 fio_flags; /* FIO_FL_* */ + __u16 fio_alignment; /* required I/O alignment on disk */ + __u32 __reserved1; /* must be zero */ + __u64 fio_max_atomic; /* max size for atomic writes */ + __u64 __reserved2[14];/* must be zero */ +}; + +/* supports atomic writes using O_(D)SYNC */ +#define FIO_FL_ATOMIC_OSYNC (1 << 0) +/* supports atomic writes committed using fsync/fdatasync/msync */ +#define FIO_FL_ATOMIC_FSYNC (1 << 1) + /* * Types of directory notifications that may be requested. */ -- 2.11.0