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authorAlan Jenkins <alan-jenkins@tuffmail.co.uk>2009-07-29 23:07:55 +0400
committerRafael J. Wysocki <rjw@sisk.pl>2009-07-29 23:07:55 +0400
commitdddac6a7b445de95515f64fdf82fe5dc36c02f26 (patch)
tree39651610292d6b0c17f210f253a0dd16b022727d /fs/block_dev.c
parentec79be26875f6c1468784876cb99192b7f41c7a5 (diff)
downloadlinux-dddac6a7b445de95515f64fdf82fe5dc36c02f26.tar.xz
PM / Hibernate: Replace bdget call with simple atomic_inc of i_count
Create bdgrab(). This function copies an existing reference to a block_device. It is safe to call from any context. Hibernation code wishes to copy a reference to the active swap device. Right now it calls bdget() under a spinlock, but this is wrong because bdget() can sleep. It doesn't need a full bdget() because we already hold a reference to active swap devices (and the spinlock protects against swapoff). Fixes http://bugzilla.kernel.org/show_bug.cgi?id=13827 Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'fs/block_dev.c')
-rw-r--r--fs/block_dev.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 3a6d4fb2a329..94dfda24c06e 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -564,6 +564,16 @@ struct block_device *bdget(dev_t dev)
EXPORT_SYMBOL(bdget);
+/**
+ * bdgrab -- Grab a reference to an already referenced block device
+ * @bdev: Block device to grab a reference to.
+ */
+struct block_device *bdgrab(struct block_device *bdev)
+{
+ atomic_inc(&bdev->bd_inode->i_count);
+ return bdev;
+}
+
long nr_blockdev_pages(void)
{
struct block_device *bdev;