Create struct bdev_handle that contains all parameters that need to be
passed to blkdev_put() and provide blkdev_get_handle_* functions that
return this structure instead of plain bdev pointer. This will
eventually allow us to pass one more argument to blkdev_put() without
too much hassle.
CC: Alasdair Kergon <agk@xxxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: Anna Schumaker <anna@xxxxxxxxxx>
CC: Chao Yu <chao@xxxxxxxxxx>
CC: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
CC: Coly Li <colyli@xxxxxxx
CC: "Darrick J. Wong" <djwong@xxxxxxxxxx>
CC: Dave Kleikamp <shaggy@xxxxxxxxxx>
CC: David Sterba <dsterba@xxxxxxxx>
CC: dm-devel@xxxxxxxxxx
CC: drbd-dev@xxxxxxxxxxxxxxxx
CC: Gao Xiang <xiang@xxxxxxxxxx>
CC: Jack Wang <jinpu.wang@xxxxxxxxx>
CC: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
CC: jfs-discussion@xxxxxxxxxxxxxxxxxxxxx
CC: Joern Engel <joern@xxxxxxxxxxxxxxx>
CC: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
CC: Kent Overstreet <kent.overstreet@xxxxxxxxx>
CC: linux-bcache@xxxxxxxxxxxxxxx
CC: linux-btrfs@xxxxxxxxxxxxxxx
CC: linux-erofs@xxxxxxxxxxxxxxxx
CC: <linux-ext4@xxxxxxxxxxxxxxx>
CC: linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx
CC: linux-mm@xxxxxxxxx
CC: linux-mtd@xxxxxxxxxxxxxxxxxxx
CC: linux-nfs@xxxxxxxxxxxxxxx
CC: linux-nilfs@xxxxxxxxxxxxxxx
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CC: "Md. Haris Iqbal" <haris.iqbal@xxxxxxxxx>
CC: Mike Snitzer <snitzer@xxxxxxxxxx>
CC: Minchan Kim <minchan@xxxxxxxxxx>
CC: ocfs2-devel@xxxxxxxxxxxxxx
CC: reiserfs-devel@xxxxxxxxxxxxxxx
CC: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
CC: Song Liu <song@xxxxxxxxxx>
CC: Sven Schnelle <svens@xxxxxxxxxxxxx>
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CC: Ted Tso <tytso@xxxxxxx>
CC: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
CC: xen-devel@xxxxxxxxxxxxxxxxxxxx
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
block/bdev.c | 47 ++++++++++++++++++++++++++++++++++++++++++
include/linux/blkdev.h | 10 +++++++++
2 files changed, 57 insertions(+)
diff --git a/block/bdev.c b/block/bdev.c
index 979e28a46b98..c75de5cac2bc 100644
--- a/block/bdev.c
+++ b/block/bdev.c
@@ -846,6 +846,24 @@ struct block_device *blkdev_get_by_dev(dev_t dev, blk_mode_t mode, void *holder,
}
EXPORT_SYMBOL(blkdev_get_by_dev);
+struct bdev_handle *blkdev_get_handle_by_dev(dev_t dev, blk_mode_t mode,
+ void *holder, const struct blk_holder_ops *hops)
+{
+ struct bdev_handle *handle = kmalloc(sizeof(struct bdev_handle),
+ GFP_KERNEL);
+ struct block_device *bdev;
+
+ if (!handle)
+ return ERR_PTR(-ENOMEM);
+ bdev = blkdev_get_by_dev(dev, mode, holder, hops);
+ if (IS_ERR(bdev))
+ return ERR_CAST(bdev);
+ handle->bdev = bdev;
+ handle->holder = holder;
+ return handle;
+}
+EXPORT_SYMBOL(blkdev_get_handle_by_dev);
+
/**
* blkdev_get_by_path - open a block device by name
* @path: path to the block device to open
@@ -884,6 +902,28 @@ struct block_device *blkdev_get_by_path(const char *path, blk_mode_t mode,
}
EXPORT_SYMBOL(blkdev_get_by_path);
+struct bdev_handle *blkdev_get_handle_by_path(const char *path, blk_mode_t mode,
+ void *holder, const struct blk_holder_ops *hops)
+{
+ struct bdev_handle *handle;
+ dev_t dev;
+ int error;
+
+ error = lookup_bdev(path, &dev);
+ if (error)
+ return ERR_PTR(error);
+
+ handle = blkdev_get_handle_by_dev(dev, mode, holder, hops);
+ if (!IS_ERR(handle) && (mode & BLK_OPEN_WRITE) &&
+ bdev_read_only(handle->bdev)) {
+ blkdev_handle_put(handle);
+ return ERR_PTR(-EACCES);
+ }
+
+ return handle;
+}
+EXPORT_SYMBOL(blkdev_get_handle_by_path);
+
void blkdev_put(struct block_device *bdev, void *holder)
{
struct gendisk *disk = bdev->bd_disk;
@@ -920,6 +960,13 @@ void blkdev_put(struct block_device *bdev, void *holder)
}
EXPORT_SYMBOL(blkdev_put);
+void blkdev_handle_put(struct bdev_handle *handle)
+{
+ blkdev_put(handle->bdev, handle->holder);
+ kfree(handle);
+}
+EXPORT_SYMBOL(blkdev_handle_put);
+
/**
* lookup_bdev() - Look up a struct block_device by name.
* @pathname: Name of the block device in the filesystem.
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index ed44a997f629..a910e9997ddd 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1471,14 +1471,24 @@ struct blk_holder_ops {
#define sb_open_mode(flags) \
(BLK_OPEN_READ | (((flags) & SB_RDONLY) ? 0 : BLK_OPEN_WRITE))
+struct bdev_handle {
+ struct block_device *bdev;
+ void *holder;
+};
+
struct block_device *blkdev_get_by_dev(dev_t dev, blk_mode_t mode, void *holder,
const struct blk_holder_ops *hops);
struct block_device *blkdev_get_by_path(const char *path, blk_mode_t mode,
void *holder, const struct blk_holder_ops *hops);
+struct bdev_handle *blkdev_get_handle_by_dev(dev_t dev, blk_mode_t mode,
+ void *holder, const struct blk_holder_ops *hops);
+struct bdev_handle *blkdev_get_handle_by_path(const char *path, blk_mode_t mode,
+ void *holder, const struct blk_holder_ops *hops);
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);
void blkdev_put(struct block_device *bdev, void *holder);
+void blkdev_handle_put(struct bdev_handle *handle);
/* just for blk-cgroup, don't use elsewhere */
struct block_device *blkdev_get_no_open(dev_t dev);
--
2.35.3
