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Diffstat (limited to 'fs')
-rw-r--r--fs/block_dev.c102
1 files changed, 87 insertions, 15 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 9633a490dab..37534573960 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -739,7 +739,7 @@ static int bd_claim_by_kobject(struct block_device *bdev, void *holder,
if (!bo)
return -ENOMEM;
- mutex_lock(&bdev->bd_mutex);
+ mutex_lock_nested(&bdev->bd_mutex, BD_MUTEX_PARTITION);
res = bd_claim(bdev, holder);
if (res || !add_bd_holder(bdev, bo))
free_bd_holder(bo);
@@ -764,7 +764,7 @@ static void bd_release_from_kobject(struct block_device *bdev,
if (!kobj)
return;
- mutex_lock(&bdev->bd_mutex);
+ mutex_lock_nested(&bdev->bd_mutex, BD_MUTEX_PARTITION);
bd_release(bdev);
if ((bo = del_bd_holder(bdev, kobj)))
free_bd_holder(bo);
@@ -822,6 +822,22 @@ struct block_device *open_by_devnum(dev_t dev, unsigned mode)
EXPORT_SYMBOL(open_by_devnum);
+static int
+blkdev_get_partition(struct block_device *bdev, mode_t mode, unsigned flags);
+
+struct block_device *open_partition_by_devnum(dev_t dev, unsigned mode)
+{
+ struct block_device *bdev = bdget(dev);
+ int err = -ENOMEM;
+ int flags = mode & FMODE_WRITE ? O_RDWR : O_RDONLY;
+ if (bdev)
+ err = blkdev_get_partition(bdev, mode, flags);
+ return err ? ERR_PTR(err) : bdev;
+}
+
+EXPORT_SYMBOL(open_partition_by_devnum);
+
+
/*
* This routine checks whether a removable media has been changed,
* and invalidates all buffer-cache-entries in that case. This
@@ -868,7 +884,11 @@ void bd_set_size(struct block_device *bdev, loff_t size)
}
EXPORT_SYMBOL(bd_set_size);
-static int do_open(struct block_device *bdev, struct file *file)
+static int
+blkdev_get_whole(struct block_device *bdev, mode_t mode, unsigned flags);
+
+static int
+do_open(struct block_device *bdev, struct file *file, unsigned int subclass)
{
struct module *owner = NULL;
struct gendisk *disk;
@@ -885,7 +905,8 @@ static int do_open(struct block_device *bdev, struct file *file)
}
owner = disk->fops->owner;
- mutex_lock(&bdev->bd_mutex);
+ mutex_lock_nested(&bdev->bd_mutex, subclass);
+
if (!bdev->bd_openers) {
bdev->bd_disk = disk;
bdev->bd_contains = bdev;
@@ -912,11 +933,11 @@ static int do_open(struct block_device *bdev, struct file *file)
ret = -ENOMEM;
if (!whole)
goto out_first;
- ret = blkdev_get(whole, file->f_mode, file->f_flags);
+ ret = blkdev_get_whole(whole, file->f_mode, file->f_flags);
if (ret)
goto out_first;
bdev->bd_contains = whole;
- mutex_lock(&whole->bd_mutex);
+ mutex_lock_nested(&whole->bd_mutex, BD_MUTEX_WHOLE);
whole->bd_part_count++;
p = disk->part[part - 1];
bdev->bd_inode->i_data.backing_dev_info =
@@ -944,7 +965,8 @@ static int do_open(struct block_device *bdev, struct file *file)
if (bdev->bd_invalidated)
rescan_partitions(bdev->bd_disk, bdev);
} else {
- mutex_lock(&bdev->bd_contains->bd_mutex);
+ mutex_lock_nested(&bdev->bd_contains->bd_mutex,
+ BD_MUTEX_PARTITION);
bdev->bd_contains->bd_part_count++;
mutex_unlock(&bdev->bd_contains->bd_mutex);
}
@@ -985,11 +1007,49 @@ int blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags)
fake_file.f_dentry = &fake_dentry;
fake_dentry.d_inode = bdev->bd_inode;
- return do_open(bdev, &fake_file);
+ return do_open(bdev, &fake_file, BD_MUTEX_NORMAL);
}
EXPORT_SYMBOL(blkdev_get);
+static int
+blkdev_get_whole(struct block_device *bdev, mode_t mode, unsigned flags)
+{
+ /*
+ * This crockload is due to bad choice of ->open() type.
+ * It will go away.
+ * For now, block device ->open() routine must _not_
+ * examine anything in 'inode' argument except ->i_rdev.
+ */
+ struct file fake_file = {};
+ struct dentry fake_dentry = {};
+ fake_file.f_mode = mode;
+ fake_file.f_flags = flags;
+ fake_file.f_dentry = &fake_dentry;
+ fake_dentry.d_inode = bdev->bd_inode;
+
+ return do_open(bdev, &fake_file, BD_MUTEX_WHOLE);
+}
+
+static int
+blkdev_get_partition(struct block_device *bdev, mode_t mode, unsigned flags)
+{
+ /*
+ * This crockload is due to bad choice of ->open() type.
+ * It will go away.
+ * For now, block device ->open() routine must _not_
+ * examine anything in 'inode' argument except ->i_rdev.
+ */
+ struct file fake_file = {};
+ struct dentry fake_dentry = {};
+ fake_file.f_mode = mode;
+ fake_file.f_flags = flags;
+ fake_file.f_dentry = &fake_dentry;
+ fake_dentry.d_inode = bdev->bd_inode;
+
+ return do_open(bdev, &fake_file, BD_MUTEX_PARTITION);
+}
+
static int blkdev_open(struct inode * inode, struct file * filp)
{
struct block_device *bdev;
@@ -1005,7 +1065,7 @@ static int blkdev_open(struct inode * inode, struct file * filp)
bdev = bd_acquire(inode);
- res = do_open(bdev, filp);
+ res = do_open(bdev, filp, BD_MUTEX_NORMAL);
if (res)
return res;
@@ -1019,13 +1079,13 @@ static int blkdev_open(struct inode * inode, struct file * filp)
return res;
}
-int blkdev_put(struct block_device *bdev)
+static int __blkdev_put(struct block_device *bdev, unsigned int subclass)
{
int ret = 0;
struct inode *bd_inode = bdev->bd_inode;
struct gendisk *disk = bdev->bd_disk;
- mutex_lock(&bdev->bd_mutex);
+ mutex_lock_nested(&bdev->bd_mutex, subclass);
lock_kernel();
if (!--bdev->bd_openers) {
sync_blockdev(bdev);
@@ -1035,7 +1095,8 @@ int blkdev_put(struct block_device *bdev)
if (disk->fops->release)
ret = disk->fops->release(bd_inode, NULL);
} else {
- mutex_lock(&bdev->bd_contains->bd_mutex);
+ mutex_lock_nested(&bdev->bd_contains->bd_mutex,
+ subclass + 1);
bdev->bd_contains->bd_part_count--;
mutex_unlock(&bdev->bd_contains->bd_mutex);
}
@@ -1051,9 +1112,8 @@ int blkdev_put(struct block_device *bdev)
}
bdev->bd_disk = NULL;
bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
- if (bdev != bdev->bd_contains) {
- blkdev_put(bdev->bd_contains);
- }
+ if (bdev != bdev->bd_contains)
+ __blkdev_put(bdev->bd_contains, subclass + 1);
bdev->bd_contains = NULL;
}
unlock_kernel();
@@ -1062,8 +1122,20 @@ int blkdev_put(struct block_device *bdev)
return ret;
}
+int blkdev_put(struct block_device *bdev)
+{
+ return __blkdev_put(bdev, BD_MUTEX_NORMAL);
+}
+
EXPORT_SYMBOL(blkdev_put);
+int blkdev_put_partition(struct block_device *bdev)
+{
+ return __blkdev_put(bdev, BD_MUTEX_PARTITION);
+}
+
+EXPORT_SYMBOL(blkdev_put_partition);
+
static int blkdev_close(struct inode * inode, struct file * filp)
{
struct block_device *bdev = I_BDEV(filp->f_mapping->host);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-05 22:59:39 +0000