block: introduce holder ops

Add a new blk_holder_ops structure, which is passed to blkdev_get_by_* and
installed in the block_device for exclusive claims.  It will be used to
allow the block layer to call back into the user of the block device for
thing like notification of a removed device or a device resize.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Link: https://lore.kernel.org/r/20230601094459.1350643-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

14 files changed, 19 insertions, 16 deletions

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 1a5d3d72d91d..cab59dab3410 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -1641,7 +1641,8 @@ static struct block_device *open_backing_dev(struct drbd_device *device,
 	int err = 0;
 
 	bdev = blkdev_get_by_path(bdev_path,
-				  FMODE_READ | FMODE_WRITE | FMODE_EXCL, claim_ptr);
+				  FMODE_READ | FMODE_WRITE | FMODE_EXCL,
+				  claim_ptr, NULL);
 	if (IS_ERR(bdev)) {
 		drbd_err(device, "open(\"%s\") failed with %ld\n",
 				bdev_path, PTR_ERR(bdev));
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index bc31bb7072a2..a73c857f5bfe 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1015,7 +1015,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
 	 * here to avoid changing device under exclusive owner.
 	 */
 	if (!(mode & FMODE_EXCL)) {
-		error = bd_prepare_to_claim(bdev, loop_configure);
+		error = bd_prepare_to_claim(bdev, loop_configure, NULL);
 		if (error)
 			goto out_putf;
 	}
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index d5d7884cedd4..377f8b345352 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2125,7 +2125,8 @@ static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
 	 * to read/write from/to it. It is already opened in O_NONBLOCK mode
 	 * so open should not fail.
 	 */
-	bdev = blkdev_get_by_dev(pd->bdev->bd_dev, FMODE_READ | FMODE_EXCL, pd);
+	bdev = blkdev_get_by_dev(pd->bdev->bd_dev, FMODE_READ | FMODE_EXCL, pd,
+				 NULL);
 	if (IS_ERR(bdev)) {
 		ret = PTR_ERR(bdev);
 		goto out;
@@ -2530,7 +2531,7 @@ static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
 		}
 	}
 
-	bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_NDELAY, NULL);
+	bdev = blkdev_get_by_dev(dev, FMODE_READ | FMODE_NDELAY, NULL, NULL);
 	if (IS_ERR(bdev))
 		return PTR_ERR(bdev);
 	sdev = scsi_device_from_queue(bdev->bd_disk->queue);
diff --git a/drivers/block/rnbd/rnbd-srv.c b/drivers/block/rnbd/rnbd-srv.c
index 2cfed2e58d64..cec22bbae2f9 100644
--- a/drivers/block/rnbd/rnbd-srv.c
+++ b/drivers/block/rnbd/rnbd-srv.c
@@ -719,7 +719,7 @@ static int process_msg_open(struct rnbd_srv_session *srv_sess,
 		goto reject;
 	}
 
-	bdev = blkdev_get_by_path(full_path, open_flags, THIS_MODULE);
+	bdev = blkdev_get_by_path(full_path, open_flags, THIS_MODULE, NULL);
 	if (IS_ERR(bdev)) {
 		ret = PTR_ERR(bdev);
 		pr_err("Opening device '%s' on session %s failed, failed to open the block device, err: %d\n",
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 4807af1d5805..43b36da9b354 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -492,7 +492,7 @@ static int xen_vbd_create(struct xen_blkif *blkif, blkif_vdev_t handle,
 	vbd->pdevice  = MKDEV(major, minor);
 
 	bdev = blkdev_get_by_dev(vbd->pdevice, vbd->readonly ?
-				 FMODE_READ : FMODE_WRITE, NULL);
+				 FMODE_READ : FMODE_WRITE, NULL, NULL);
 
 	if (IS_ERR(bdev)) {
 		pr_warn("xen_vbd_create: device %08x could not be opened\n",
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index b86691d2133e..0bc779446c6f 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -508,7 +508,7 @@ static ssize_t backing_dev_store(struct device *dev,
 	}
 
 	bdev = blkdev_get_by_dev(inode->i_rdev,
-			FMODE_READ | FMODE_WRITE | FMODE_EXCL, zram);
+			FMODE_READ | FMODE_WRITE | FMODE_EXCL, zram, NULL);
 	if (IS_ERR(bdev)) {
 		err = PTR_ERR(bdev);
 		bdev = NULL;
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 7e9d19fd21dd..d84c09a73af8 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -2560,7 +2560,7 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
 	err = "failed to open device";
 	bdev = blkdev_get_by_path(strim(path),
 				  FMODE_READ|FMODE_WRITE|FMODE_EXCL,
-				  sb);
+				  sb, NULL);
 	if (IS_ERR(bdev)) {
 		if (bdev == ERR_PTR(-EBUSY)) {
 			dev_t dev;
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 3b694ba3a106..d759f8bdb3df 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -746,7 +746,7 @@ static struct table_device *open_table_device(struct mapped_device *md,
 		return ERR_PTR(-ENOMEM);
 	refcount_set(&td->count, 1);
 
-	bdev = blkdev_get_by_dev(dev, mode | FMODE_EXCL, _dm_claim_ptr);
+	bdev = blkdev_get_by_dev(dev, mode | FMODE_EXCL, _dm_claim_ptr, NULL);
 	if (IS_ERR(bdev)) {
 		r = PTR_ERR(bdev);
 		goto out_free_td;
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 6a559a7e89c0..fabf9c543735 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3642,7 +3642,7 @@ static struct md_rdev *md_import_device(dev_t newdev, int super_format, int supe
 
 	rdev->bdev = blkdev_get_by_dev(newdev,
 			FMODE_READ | FMODE_WRITE | FMODE_EXCL,
-			super_format == -2 ? &claim_rdev : rdev);
+			super_format == -2 ? &claim_rdev : rdev, NULL);
 	if (IS_ERR(rdev->bdev)) {
 		pr_warn("md: could not open device unknown-block(%u,%u).\n",
 			MAJOR(newdev), MINOR(newdev));
diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
index 4cd37ec45762..7ac82c6fe350 100644
--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -235,7 +235,7 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size,
 		return NULL;
 
 	/* Get a handle on the device */
-	bdev = blkdev_get_by_path(devname, mode, dev);
+	bdev = blkdev_get_by_path(devname, mode, dev, NULL);
 
 #ifndef MODULE
 	/*
@@ -257,7 +257,7 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size,
 		devt = name_to_dev_t(devname);
 		if (!devt)
 			continue;
-		bdev = blkdev_get_by_dev(devt, mode, dev);
+		bdev = blkdev_get_by_dev(devt, mode, dev, NULL);
 	}
 #endif
 
diff --git a/drivers/nvme/target/io-cmd-bdev.c b/drivers/nvme/target/io-cmd-bdev.c
index c2d6cea0236b..9b6d6d85c725 100644
--- a/drivers/nvme/target/io-cmd-bdev.c
+++ b/drivers/nvme/target/io-cmd-bdev.c
@@ -85,7 +85,7 @@ int nvmet_bdev_ns_enable(struct nvmet_ns *ns)
 		return -ENOTBLK;
 
 	ns->bdev = blkdev_get_by_path(ns->device_path,
-			FMODE_READ | FMODE_WRITE, NULL);
+			FMODE_READ | FMODE_WRITE, NULL, NULL);
 	if (IS_ERR(ns->bdev)) {
 		ret = PTR_ERR(ns->bdev);
 		if (ret != -ENOTBLK) {
diff --git a/drivers/s390/block/dasd_genhd.c b/drivers/s390/block/dasd_genhd.c
index 998a961e1704..f21198bc483e 100644
--- a/drivers/s390/block/dasd_genhd.c
+++ b/drivers/s390/block/dasd_genhd.c
@@ -130,7 +130,7 @@ int dasd_scan_partitions(struct dasd_block *block)
 	struct block_device *bdev;
 	int rc;
 
-	bdev = blkdev_get_by_dev(disk_devt(block->gdp), FMODE_READ, NULL);
+	bdev = blkdev_get_by_dev(disk_devt(block->gdp), FMODE_READ, NULL, NULL);
 	if (IS_ERR(bdev)) {
 		DBF_DEV_EVENT(DBF_ERR, block->base,
 			      "scan partitions error, blkdev_get returned %ld",
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index cc838ffd1294..a5cbbefa78ee 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -114,7 +114,7 @@ static int iblock_configure_device(struct se_device *dev)
 	else
 		dev->dev_flags |= DF_READ_ONLY;
 
-	bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev);
+	bd = blkdev_get_by_path(ib_dev->ibd_udev_path, mode, ib_dev, NULL);
 	if (IS_ERR(bd)) {
 		ret = PTR_ERR(bd);
 		goto out_free_bioset;
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index e7425549e39c..e3494e036c6c 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -367,7 +367,8 @@ static int pscsi_create_type_disk(struct se_device *dev, struct scsi_device *sd)
 	 * for TYPE_DISK and TYPE_ZBC using supplied udev_path
 	 */
 	bd = blkdev_get_by_path(dev->udev_path,
-				FMODE_WRITE|FMODE_READ|FMODE_EXCL, pdv);
+				FMODE_WRITE|FMODE_READ|FMODE_EXCL, pdv,
+				NULL);
 	if (IS_ERR(bd)) {
 		pr_err("pSCSI: blkdev_get_by_path() failed\n");
 		scsi_device_put(sd);