[vfs.all,05/26] block: add a helper bdev_read_folio()

Message ID	20240406090930.2252838-6-yukuai1@huaweicloud.com (mailing list archive)
State	New
Headers	show Received: from dggsgout11.his.huawei.com (unknown [45.249.212.51]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 78E54225CF; Sat, 6 Apr 2024 09:17:47 +0000 (UTC) From: Yu Kuai <yukuai1@huaweicloud.com> To: jack@suse.cz, hch@lst.de, brauner@kernel.org, viro@zeniv.linux.org.uk, axboe@kernel.dk Cc: linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, yi.zhang@huawei.com, yangerkun@huawei.com, yukuai3@huawei.com Subject: [PATCH vfs.all 05/26] block: add a helper bdev_read_folio() Date: Sat, 6 Apr 2024 17:09:09 +0800 Message-Id: <20240406090930.2252838-6-yukuai1@huaweicloud.com> In-Reply-To: <20240406090930.2252838-1-yukuai1@huaweicloud.com> References: <20240406090930.2252838-1-yukuai1@huaweicloud.com> Precedence: bulk MIME-Version: 1.0 Content-Transfer-Encoding: 8bit
Series	fs & block: remove bdev->bd_inode \| expand [vfs.all,00/26] fs & block: remove bdev->bd_inode [vfs.all,01/26] block: move two helpers into bdev.c [vfs.all,02/26] block: remove sync_blockdev_nowait() [vfs.all,03/26] block: remove sync_blockdev_range() [vfs.all,04/26] block: prevent direct access of bd_inode [vfs.all,05/26] block: add a helper bdev_read_folio() [vfs.all,06/26] bcachefs: remove dead function bdev_sectors() [vfs.all,07/26] cramfs: prevent direct access of bd_inode [vfs.all,08/26] erofs: prevent direct access of bd_inode [vfs.all,09/26] nilfs2: prevent direct access of bd_inode [vfs.all,10/26] gfs2: prevent direct access of bd_inode [vfs.all,11/26] btrfs: prevent direct access of bd_inode [vfs.all,12/26] ext4: remove block_device_ejected() [vfs.all,13/26] ext4: prevent direct access of bd_inode [vfs.all,14/26] jbd2: prevent direct access of bd_inode [vfs.all,15/26] s390/dasd: use bdev api in dasd_format() [vfs.all,16/26] bcache: prevent direct access of bd_inode [vfs.all,17/26] block2mtd: prevent direct access of bd_inode [vfs.all,18/26] scsi: use bdev helper in scsi_bios_ptable() [vfs.all,19/26] dm-vdo: convert to use bdev_file [vfs.all,20/26] block: factor out a helper init_bdev_file() [vfs.all,21/26] block: fix module reference leakage from bdev_open_by_dev error path [vfs.all,22/26] block: stash a bdev_file to read/write raw blcok_device [vfs.all,23/26] iomap: add helpers helpers to get and set bdev [vfs.all,24/26] iomap: convert to use bdev_file [vfs.all,25/26] buffer: add helpers to get and set bdev [vfs.all,26/26] buffer: convert to use bdev_file

Message ID

20240406090930.2252838-6-yukuai1@huaweicloud.com (mailing list archive)

State

New

Headers

From: Yu Kuai <yukuai1@huaweicloud.com>
To: jack@suse.cz,
	hch@lst.de,
	brauner@kernel.org,
	viro@zeniv.linux.org.uk,
	axboe@kernel.dk
Cc: linux-fsdevel@vger.kernel.org,
	linux-block@vger.kernel.org,
	yi.zhang@huawei.com,
	yangerkun@huawei.com,
	yukuai3@huawei.com
Subject: [PATCH vfs.all 05/26] block: add a helper bdev_read_folio()
Date: Sat,  6 Apr 2024 17:09:09 +0800
Message-Id: <20240406090930.2252838-6-yukuai1@huaweicloud.com>
In-Reply-To: <20240406090930.2252838-1-yukuai1@huaweicloud.com>
References: <20240406090930.2252838-1-yukuai1@huaweicloud.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

Series

fs & block: remove bdev->bd_inode | expand

Commit Message

Yu Kuai April 6, 2024, 9:09 a.m. UTC

From: Yu Kuai <yukuai3@huawei.com>

Currently scsi driver is reading without opening disk as file(
scsi_bios_ptable()), factor out a helper to read into block device page
cache to prevent access bd_inode directly from scsi.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
---
 block/bdev.c           | 19 +++++++++++++++++++
 include/linux/blkdev.h |  1 +
 2 files changed, 20 insertions(+)

diff --git a/block/bdev.c b/block/bdev.c
index c0b30392563a..4335df6d1266 100644
--- a/block/bdev.c
+++ b/block/bdev.c
@@ -1266,6 +1266,25 @@  unsigned int block_size(struct block_device *bdev)
 }
 EXPORT_SYMBOL_GPL(block_size);
 
+/**
+ * bdev_read_folio - Read into block device page cache.
+ * @bdev: the block device which holds the cache to read.
+ * @pos: the offset that allocated folio will contain.
+ *
+ * Read one page into the block device page cache. If it succeeds, the folio
+ * returned will contain @pos;
+ *
+ * This is only used for scsi_bios_ptable(), the bdev is not opened as files.
+ *
+ * Return: Uptodate folio on success, ERR_PTR() on failure.
+ */
+struct folio *bdev_read_folio(struct block_device *bdev, loff_t pos)
+{
+	return mapping_read_folio_gfp(bdev_mapping(bdev),
+				      pos >> PAGE_SHIFT, GFP_KERNEL);
+}
+EXPORT_SYMBOL_GPL(bdev_read_folio);
+
 static int __init setup_bdev_allow_write_mounted(char *str)
 {
 	if (kstrtobool(str, &bdev_allow_write_mounted))
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 08d4e6a0940c..bc840e0fb6e5 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1519,6 +1519,7 @@  struct file *bdev_file_open_by_path(const char *path, blk_mode_t mode,
 int bd_prepare_to_claim(struct block_device *bdev, void *holder,
 		const struct blk_holder_ops *hops);
 void bd_abort_claiming(struct block_device *bdev, void *holder);
+struct folio *bdev_read_folio(struct block_device *bdev, loff_t pos);
 
 /* just for blk-cgroup, don't use elsewhere */
 struct block_device *blkdev_get_no_open(dev_t dev);

[vfs.all,05/26] block: add a helper bdev_read_folio()

Commit Message

Patch