linux-kernel - [PATCH 01/15] fs: add write stream information to statx

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Message-ID: <20241119121632.1225556-2-hch@lst.de>
Date: Tue, 19 Nov 2024 13:16:15 +0100
From: Christoph Hellwig <hch@....de>
To: Jens Axboe <axboe@...nel.dk>
Cc: Christian Brauner <brauner@...nel.org>,
	Keith Busch <kbusch@...nel.org>,
	Sagi Grimberg <sagi@...mberg.me>,
	Kanchan Joshi <joshi.k@...sung.com>,
	Hui Qi <hui81.qi@...sung.com>,
	Nitesh Shetty <nj.shetty@...sung.com>,
	Jan Kara <jack@...e.cz>,
	Pavel Begunkov <asml.silence@...il.com>,
	linux-block@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	linux-nvme@...ts.infradead.org,
	linux-fsdevel@...r.kernel.org,
	io-uring@...r.kernel.org
Subject: [PATCH 01/15] fs: add write stream information to statx

From: Keith Busch <kbusch@...nel.org>

Add new statx field to report the maximum number of write streams
supported and the granularity for them.

Signed-off-by: Keith Busch <kbusch@...nel.org>
[hch: s/write_hint/write_stream/g, add granularity]
Signed-off-by: Christoph Hellwig <hch@....de>
---
 fs/stat.c                 | 2 ++
 include/linux/stat.h      | 2 ++
 include/uapi/linux/stat.h | 7 +++++--
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/fs/stat.c b/fs/stat.c
index 41e598376d7e..aa2b7fa4a877 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -704,6 +704,8 @@ cp_statx(const struct kstat *stat, struct statx __user *buffer)
 	tmp.stx_atomic_write_unit_min = stat->atomic_write_unit_min;
 	tmp.stx_atomic_write_unit_max = stat->atomic_write_unit_max;
 	tmp.stx_atomic_write_segments_max = stat->atomic_write_segments_max;
+	tmp.stx_write_stream_granularity = stat->write_stream_granularity;
+	tmp.stx_write_stream_max = stat->write_stream_max;
 
 	return copy_to_user(buffer, &tmp, sizeof(tmp)) ? -EFAULT : 0;
 }
diff --git a/include/linux/stat.h b/include/linux/stat.h
index 3d900c86981c..36d4dfb291ab 100644
--- a/include/linux/stat.h
+++ b/include/linux/stat.h
@@ -57,6 +57,8 @@ struct kstat {
 	u32		atomic_write_unit_min;
 	u32		atomic_write_unit_max;
 	u32		atomic_write_segments_max;
+	u32		write_stream_granularity;
+	u16		write_stream_max;
 };
 
 /* These definitions are internal to the kernel for now. Mainly used by nfsd. */
diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h
index 887a25286441..547c62a1a3a7 100644
--- a/include/uapi/linux/stat.h
+++ b/include/uapi/linux/stat.h
@@ -132,9 +132,11 @@ struct statx {
 	__u32	stx_atomic_write_unit_max;	/* Max atomic write unit in bytes */
 	/* 0xb0 */
 	__u32   stx_atomic_write_segments_max;	/* Max atomic write segment count */
-	__u32   __spare1[1];
+	__u32   stx_write_stream_granularity;
 	/* 0xb8 */
-	__u64	__spare3[9];	/* Spare space for future expansion */
+	__u16   stx_write_stream_max;
+	__u16	__sparse2[3];
+	__u64	__spare3[8];	/* Spare space for future expansion */
 	/* 0x100 */
 };
 
@@ -164,6 +166,7 @@ struct statx {
 #define STATX_MNT_ID_UNIQUE	0x00004000U	/* Want/got extended stx_mount_id */
 #define STATX_SUBVOL		0x00008000U	/* Want/got stx_subvol */
 #define STATX_WRITE_ATOMIC	0x00010000U	/* Want/got atomic_write_* fields */
+#define STATX_WRITE_STREAM	0x00020000U	/* Want/got write_stream_* */
 
 #define STATX__RESERVED		0x80000000U	/* Reserved for future struct statx expansion */
 
-- 
2.45.2