linux-raid.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: Jens Axboe <axboe@kernel.dk>
Cc: "Justin Sanders" <justin@coraid.com>,
	"Josef Bacik" <josef@toxicpanda.com>,
	"Ilya Dryomov" <idryomov@gmail.com>,
	"Jack Wang" <jinpu.wang@cloud.ionos.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	"Jason Wang" <jasowang@redhat.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Stefan Hajnoczi" <stefanha@redhat.com>,
	"Konrad Rzeszutek Wilk" <konrad.wilk@oracle.com>,
	"Roger Pau Monné" <roger.pau@citrix.com>,
	"Minchan Kim" <minchan@kernel.org>,
	"Mike Snitzer" <snitzer@redhat.com>, "Song Liu" <song@kernel.org>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	dm-devel@redhat.com, linux-block@vger.kernel.org,
	drbd-dev@lists.linbit.com, nbd@other.debian.org,
	ceph-devel@vger.kernel.org, xen-devel@lists.xenproject.org,
	linux-raid@vger.kernel.org, linux-nvme@lists.infradead.org,
	linux-scsi@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: [PATCH 67/78] block: simplify the block device claiming interface
Date: Mon, 16 Nov 2020 15:57:58 +0100	[thread overview]
Message-ID: <20201116145809.410558-68-hch@lst.de> (raw)
In-Reply-To: <20201116145809.410558-1-hch@lst.de>

Stop passing the whole device as a separate argument given that it
can be trivially deducted.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/loop.c   | 12 +++-----
 fs/block_dev.c         | 69 +++++++++++++++++++-----------------------
 include/linux/blkdev.h |  6 ++--
 3 files changed, 38 insertions(+), 49 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index b42c728620c9e4..599e94a7e69259 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1071,7 +1071,6 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
 	struct file	*file;
 	struct inode	*inode;
 	struct address_space *mapping;
-	struct block_device *claimed_bdev = NULL;
 	int		error;
 	loff_t		size;
 	bool		partscan;
@@ -1090,8 +1089,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
 	 * here to avoid changing device under exclusive owner.
 	 */
 	if (!(mode & FMODE_EXCL)) {
-		claimed_bdev = bdev->bd_contains;
-		error = bd_prepare_to_claim(bdev, claimed_bdev, loop_configure);
+		error = bd_prepare_to_claim(bdev, loop_configure);
 		if (error)
 			goto out_putf;
 	}
@@ -1178,15 +1176,15 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
 	mutex_unlock(&loop_ctl_mutex);
 	if (partscan)
 		loop_reread_partitions(lo, bdev);
-	if (claimed_bdev)
-		bd_abort_claiming(bdev, claimed_bdev, loop_configure);
+	if (!(mode & FMODE_EXCL))
+		bd_abort_claiming(bdev, loop_configure);
 	return 0;
 
 out_unlock:
 	mutex_unlock(&loop_ctl_mutex);
 out_bdev:
-	if (claimed_bdev)
-		bd_abort_claiming(bdev, claimed_bdev, loop_configure);
+	if (!(mode & FMODE_EXCL))
+		bd_abort_claiming(bdev, loop_configure);
 out_putf:
 	fput(file);
 out:
diff --git a/fs/block_dev.c b/fs/block_dev.c
index f36788d7699302..fd4df132a97590 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -110,24 +110,20 @@ EXPORT_SYMBOL(invalidate_bdev);
 int truncate_bdev_range(struct block_device *bdev, fmode_t mode,
 			loff_t lstart, loff_t lend)
 {
-	struct block_device *claimed_bdev = NULL;
-	int err;
-
 	/*
 	 * If we don't hold exclusive handle for the device, upgrade to it
 	 * while we discard the buffer cache to avoid discarding buffers
 	 * under live filesystem.
 	 */
 	if (!(mode & FMODE_EXCL)) {
-		claimed_bdev = bdev->bd_contains;
-		err = bd_prepare_to_claim(bdev, claimed_bdev,
-					  truncate_bdev_range);
+		int err = bd_prepare_to_claim(bdev, truncate_bdev_range);
 		if (err)
 			return err;
 	}
+
 	truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend);
-	if (claimed_bdev)
-		bd_abort_claiming(bdev, claimed_bdev, truncate_bdev_range);
+	if (!(mode & FMODE_EXCL))
+		bd_abort_claiming(bdev, truncate_bdev_range);
 	return 0;
 }
 EXPORT_SYMBOL(truncate_bdev_range);
@@ -1055,7 +1051,6 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole,
 /**
  * bd_prepare_to_claim - claim a block device
  * @bdev: block device of interest
- * @whole: the whole device containing @bdev, may equal @bdev
  * @holder: holder trying to claim @bdev
  *
  * Claim @bdev.  This function fails if @bdev is already claimed by another
@@ -1065,9 +1060,10 @@ static bool bd_may_claim(struct block_device *bdev, struct block_device *whole,
  * RETURNS:
  * 0 if @bdev can be claimed, -EBUSY otherwise.
  */
-int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole,
-		void *holder)
+int bd_prepare_to_claim(struct block_device *bdev, void *holder)
 {
+	struct block_device *whole = bdev->bd_contains;
+
 retry:
 	spin_lock(&bdev_lock);
 	/* if someone else claimed, fail */
@@ -1107,15 +1103,15 @@ static void bd_clear_claiming(struct block_device *whole, void *holder)
 /**
  * bd_finish_claiming - finish claiming of a block device
  * @bdev: block device of interest
- * @whole: whole block device
  * @holder: holder that has claimed @bdev
  *
  * Finish exclusive open of a block device. Mark the device as exlusively
  * open by the holder and wake up all waiters for exclusive open to finish.
  */
-static void bd_finish_claiming(struct block_device *bdev,
-		struct block_device *whole, void *holder)
+static void bd_finish_claiming(struct block_device *bdev, void *holder)
 {
+	struct block_device *whole = bdev->bd_contains;
+
 	spin_lock(&bdev_lock);
 	BUG_ON(!bd_may_claim(bdev, whole, holder));
 	/*
@@ -1140,11 +1136,10 @@ static void bd_finish_claiming(struct block_device *bdev,
  * also used when exclusive open is not actually desired and we just needed
  * to block other exclusive openers for a while.
  */
-void bd_abort_claiming(struct block_device *bdev, struct block_device *whole,
-		       void *holder)
+void bd_abort_claiming(struct block_device *bdev, void *holder)
 {
 	spin_lock(&bdev_lock);
-	bd_clear_claiming(whole, holder);
+	bd_clear_claiming(bdev->bd_contains, holder);
 	spin_unlock(&bdev_lock);
 }
 EXPORT_SYMBOL(bd_abort_claiming);
@@ -1439,7 +1434,7 @@ static int bdev_get_gendisk(struct gendisk *disk)
 static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
 		int for_part)
 {
-	struct block_device *whole = NULL, *claiming = NULL;
+	struct block_device *whole = NULL;
 	struct gendisk *disk = bdev->bd_disk;
 	int ret;
 	bool first_open = false, unblock_events = true, need_restart;
@@ -1460,11 +1455,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
 
 	if (!for_part && (mode & FMODE_EXCL)) {
 		WARN_ON_ONCE(!holder);
-		if (whole)
-			claiming = whole;
-		else
-			claiming = bdev;
-		ret = bd_prepare_to_claim(bdev, claiming, holder);
+		ret = bd_prepare_to_claim(bdev, holder);
 		if (ret)
 			goto out_put_whole;
 	}
@@ -1541,21 +1532,23 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
 		}
 	}
 	bdev->bd_openers++;
-	if (for_part)
+	if (for_part) {
 		bdev->bd_part_count++;
-	if (claiming)
-		bd_finish_claiming(bdev, claiming, holder);
+	} else if (mode & FMODE_EXCL) {
+		bd_finish_claiming(bdev, holder);
 
-	/*
-	 * Block event polling for write claims if requested.  Any write holder
-	 * makes the write_holder state stick until all are released.  This is
-	 * good enough and tracking individual writeable reference is too
-	 * fragile given the way @mode is used in blkdev_get/put().
-	 */
-	if (claiming && (mode & FMODE_WRITE) && !bdev->bd_write_holder &&
-	    (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) {
-		bdev->bd_write_holder = true;
-		unblock_events = false;
+		/*
+		 * Block event polling for write claims if requested.  Any write
+		 * holder makes the write_holder state stick until all are
+		 * released.  This is good enough and tracking individual
+		 * writeable reference is too fragile given the way @mode is
+		 * used in blkdev_get/put().
+		 */
+		if ((mode & FMODE_WRITE) && !bdev->bd_write_holder &&
+		    (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) {
+			bdev->bd_write_holder = true;
+			unblock_events = false;
+		}
 	}
 	mutex_unlock(&bdev->bd_mutex);
 
@@ -1576,8 +1569,8 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
 		__blkdev_put(bdev->bd_contains, mode, 1);
 	bdev->bd_contains = NULL;
  out_unlock_bdev:
-	if (claiming)
-		bd_abort_claiming(bdev, claiming, holder);
+	if (!for_part && (mode & FMODE_EXCL))
+		bd_abort_claiming(bdev, holder);
 	mutex_unlock(&bdev->bd_mutex);
 	disk_unblock_events(disk);
  out_put_whole:
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 044d9dd159d882..696b2f9c5529d8 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1988,10 +1988,8 @@ void blkdev_show(struct seq_file *seqf, off_t offset);
 struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
 		void *holder);
 struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder);
-int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole,
-		void *holder);
-void bd_abort_claiming(struct block_device *bdev, struct block_device *whole,
-		void *holder);
+int bd_prepare_to_claim(struct block_device *bdev, void *holder);
+void bd_abort_claiming(struct block_device *bdev, void *holder);
 void blkdev_put(struct block_device *bdev, fmode_t mode);
 
 struct block_device *bdev_alloc(struct gendisk *disk, u8 partno);
-- 
2.29.2


  parent reply	other threads:[~2020-11-16 15:01 UTC|newest]

Thread overview: 113+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-16 14:56 cleanup updating the size of block devices v3 Christoph Hellwig
2020-11-16 14:56 ` [PATCH 01/78] block: remove the call to __invalidate_device in check_disk_size_change Christoph Hellwig
2020-11-16 14:56 ` [PATCH 02/78] loop: let set_capacity_revalidate_and_notify update the bdev size Christoph Hellwig
2020-11-16 14:56 ` [PATCH 03/78] nvme: " Christoph Hellwig
2020-11-16 14:56 ` [PATCH 04/78] sd: update the bdev size in sd_revalidate_disk Christoph Hellwig
2020-11-16 14:56 ` [PATCH 05/78] block: remove the update_bdev parameter to set_capacity_revalidate_and_notify Christoph Hellwig
2020-11-16 14:56 ` [PATCH 06/78] nbd: remove the call to set_blocksize Christoph Hellwig
2020-11-16 14:56 ` [PATCH 07/78] nbd: move the task_recv check into nbd_size_update Christoph Hellwig
2020-11-16 14:56 ` [PATCH 08/78] nbd: refactor size updates Christoph Hellwig
2020-11-16 14:57 ` [PATCH 09/78] nbd: validate the block size in nbd_set_size Christoph Hellwig
2020-11-16 14:57 ` [PATCH 10/78] nbd: use set_capacity_and_notify Christoph Hellwig
2020-11-16 14:57 ` [PATCH 11/78] aoe: don't call set_capacity from irq context Christoph Hellwig
2020-11-16 14:57 ` [PATCH 12/78] dm: use set_capacity_and_notify Christoph Hellwig
2021-02-12 15:45   ` Mike Snitzer
2021-02-16 11:46     ` Christoph Hellwig
2020-11-16 14:57 ` [PATCH 13/78] pktcdvd: " Christoph Hellwig
2020-11-16 14:57 ` [PATCH 14/78] nvme: use set_capacity_and_notify in nvme_set_queue_dying Christoph Hellwig
2020-11-16 14:57 ` [PATCH 15/78] drbd: use set_capacity_and_notify Christoph Hellwig
2020-11-16 14:57 ` [PATCH 16/78] rbd: " Christoph Hellwig
2020-11-16 14:57 ` [PATCH 17/78] rnbd: " Christoph Hellwig
2020-11-16 14:57 ` [PATCH 18/78] zram: " Christoph Hellwig
2020-11-16 14:57 ` [PATCH 19/78] dm-raid: " Christoph Hellwig
2020-11-16 14:57 ` [PATCH 20/78] md: " Christoph Hellwig
2020-11-16 14:57 ` [PATCH 21/78] md: remove a spurious call to revalidate_disk_size in update_size Christoph Hellwig
2020-11-16 14:57 ` [PATCH 22/78] virtio-blk: remove a spurious call to revalidate_disk_size Christoph Hellwig
2020-11-16 14:57 ` [PATCH 23/78] block: unexport revalidate_disk_size Christoph Hellwig
2020-11-16 14:57 ` [PATCH 24/78] mtd_blkdevs: don't override BLKFLSBUF Christoph Hellwig
2020-11-16 14:57 ` [PATCH 25/78] block: don't call into the driver for BLKFLSBUF Christoph Hellwig
2020-11-16 14:57 ` [PATCH 26/78] block: add a new set_read_only method Christoph Hellwig
2020-11-16 14:57 ` [PATCH 27/78] rbd: implement ->set_read_only to hook into BLKROSET processing Christoph Hellwig
2020-11-16 14:57 ` [PATCH 28/78] md: " Christoph Hellwig
2020-11-16 17:37   ` Song Liu
2020-11-16 14:57 ` [PATCH 29/78] dasd: " Christoph Hellwig
2020-11-16 14:57 ` [PATCH 30/78] block: don't call into the driver for BLKROSET Christoph Hellwig
2020-11-20  7:19   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 31/78] loop: use set_disk_ro Christoph Hellwig
2020-11-20  7:20   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 32/78] block: remove set_device_ro Christoph Hellwig
2020-11-20  7:20   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 33/78] block: remove __blkdev_driver_ioctl Christoph Hellwig
2020-11-20  7:22   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 34/78] block: propagate BLKROSET to all partitions Christoph Hellwig
2020-11-20  7:23   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 35/78] block: cleanup del_gendisk a bit Christoph Hellwig
2020-11-16 14:57 ` [PATCH 36/78] block: open code kobj_map into in block/genhd.c Christoph Hellwig
2020-11-16 14:57 ` [PATCH 37/78] block: split block_class_lock Christoph Hellwig
2020-11-16 14:57 ` [PATCH 38/78] block: rework requesting modules for unclaimed devices Christoph Hellwig
2020-11-16 14:57 ` [PATCH 39/78] block: add an optional probe callback to major_names Christoph Hellwig
2020-11-16 14:57 ` [PATCH 40/78] ide: remove ide_{,un}register_region Christoph Hellwig
2020-11-16 14:57 ` [PATCH 41/78] swim: don't call blk_register_region Christoph Hellwig
2020-11-16 14:57 ` [PATCH 42/78] sd: use __register_blkdev to avoid a modprobe for an unregistered dev_t Christoph Hellwig
2020-11-16 14:57 ` [PATCH 43/78] brd: use __register_blkdev to allocate devices on demand Christoph Hellwig
2020-11-16 14:57 ` [PATCH 44/78] loop: " Christoph Hellwig
2020-11-16 14:57 ` [PATCH 45/78] md: " Christoph Hellwig
2020-11-16 14:57 ` [PATCH 46/78] ide: switch to __register_blkdev for command set probing Christoph Hellwig
2020-11-16 14:57 ` [PATCH 47/78] floppy: use a separate gendisk for each media format Christoph Hellwig
2020-11-16 14:57 ` [PATCH 48/78] amiflop: use separate gendisks for Amiga vs MS-DOS mode Christoph Hellwig
2020-11-16 14:57 ` [PATCH 49/78] ataflop: use a separate gendisk for each media format Christoph Hellwig
2020-11-16 14:57 ` [PATCH 50/78] z2ram: reindent Christoph Hellwig
2020-11-16 14:57 ` [PATCH 51/78] z2ram: use separate gendisk for the different modes Christoph Hellwig
2020-11-16 14:57 ` [PATCH 52/78] block: switch gendisk lookup to a simple xarray Christoph Hellwig
2020-11-16 14:57 ` [PATCH 53/78] blk-cgroup: fix a hd_struct leak in blkcg_fill_root_iostats Christoph Hellwig
2020-11-20  7:25   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 54/78] block: remove a duplicate __disk_get_part prototype Christoph Hellwig
2020-11-20  7:25   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 55/78] block: change the hash used for looking up block devices Christoph Hellwig
2020-11-20  7:26   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 56/78] init: refactor name_to_dev_t Christoph Hellwig
2020-11-20  7:31   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 57/78] init: refactor devt_from_partuuid Christoph Hellwig
2020-11-20  7:33   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 58/78] init: cleanup match_dev_by_uuid and match_dev_by_label Christoph Hellwig
2020-11-20  7:34   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 59/78] mtip32xx: remove the call to fsync_bdev on removal Christoph Hellwig
2020-11-20  7:35   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 60/78] zram: remove the claim mechanism Christoph Hellwig
2020-11-20  7:37   ` Hannes Reinecke
2020-11-26  1:11   ` Minchan Kim
2020-11-26  9:59     ` Christoph Hellwig
2020-11-16 14:57 ` [PATCH 61/78] zram: do not call set_blocksize Christoph Hellwig
2020-11-20  7:38   ` Hannes Reinecke
2020-11-26  1:16   ` Minchan Kim
2020-11-16 14:57 ` [PATCH 62/78] loop: " Christoph Hellwig
2020-11-20  7:38   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 63/78] bcache: remove a superflous lookup_bdev all Christoph Hellwig
2020-11-16 14:57 ` [PATCH 64/78] dm: simplify flush_bio initialization in __send_empty_flush Christoph Hellwig
2020-11-20  7:41   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 65/78] dm: remove the block_device reference in struct mapped_device Christoph Hellwig
2020-11-20  7:43   ` Hannes Reinecke
2020-11-16 14:57 ` [PATCH 66/78] block: keep a block_device reference for each hd_struct Christoph Hellwig
2020-11-20  7:50   ` Hannes Reinecke
2020-11-16 14:57 ` Christoph Hellwig [this message]
2020-11-20  7:51   ` [PATCH 67/78] block: simplify the block device claiming interface Hannes Reinecke
2020-11-16 14:57 ` [PATCH 68/78] block: remove ->bd_contains Christoph Hellwig
2020-11-20  7:52   ` Hannes Reinecke
2020-11-16 14:58 ` [PATCH 69/78] block: remove the nr_sects field in struct hd_struct Christoph Hellwig
2020-11-20  7:55   ` Hannes Reinecke
2020-11-16 14:58 ` [PATCH 70/78] block: replace bd_mutex with a per-gendisk mutex Christoph Hellwig
2020-11-20  7:58   ` Hannes Reinecke
2020-11-16 14:58 ` [PATCH 71/78] block: add a bdev_kobj helper Christoph Hellwig
2020-11-20  7:59   ` Hannes Reinecke
2020-11-16 14:58 ` [PATCH 72/78] block: use disk_part_iter_exit in disk_part_iter_next Christoph Hellwig
2020-11-20  7:59   ` Hannes Reinecke
2020-11-16 14:58 ` [PATCH 73/78] block: use put_device in put_disk Christoph Hellwig
2020-11-20  8:02   ` Hannes Reinecke
2020-11-16 14:58 ` [PATCH 74/78] block: merge struct block_device and struct hd_struct Christoph Hellwig
2020-11-20  8:58   ` Hannes Reinecke
2020-11-16 14:58 ` [PATCH 75/78] block: stop using bdget_disk for partition 0 Christoph Hellwig
2020-11-16 14:58 ` [PATCH 76/78] filemap: use ->f_mapping over ->i_mapping consistently Christoph Hellwig
2020-11-16 14:58 ` [PATCH 77/78] fs: simplify the get_super_thawed interface Christoph Hellwig
2020-11-16 14:58 ` [PATCH 78/78] block: remove i_bdev Christoph Hellwig
2020-11-16 15:05 ` cleanup updating the size of block devices v3 Christoph Hellwig
2020-11-16 15:40 ` Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201116145809.410558-68-hch@lst.de \
    --to=hch@lst.de \
    --cc=axboe@kernel.dk \
    --cc=ceph-devel@vger.kernel.org \
    --cc=dm-devel@redhat.com \
    --cc=drbd-dev@lists.linbit.com \
    --cc=idryomov@gmail.com \
    --cc=jasowang@redhat.com \
    --cc=jinpu.wang@cloud.ionos.com \
    --cc=josef@toxicpanda.com \
    --cc=justin@coraid.com \
    --cc=konrad.wilk@oracle.com \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-nvme@lists.infradead.org \
    --cc=linux-raid@vger.kernel.org \
    --cc=linux-scsi@vger.kernel.org \
    --cc=martin.petersen@oracle.com \
    --cc=minchan@kernel.org \
    --cc=mst@redhat.com \
    --cc=nbd@other.debian.org \
    --cc=pbonzini@redhat.com \
    --cc=roger.pau@citrix.com \
    --cc=snitzer@redhat.com \
    --cc=song@kernel.org \
    --cc=stefanha@redhat.com \
    --cc=xen-devel@lists.xenproject.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).