Merge tag 'pinctrl' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

[firefly-linux-kernel-4.4.55.git] / fs / block_dev.c

diff --git a/fs/block_dev.c b/fs/block_dev.c
index c2bbe1fb132632c14ebb2ea0675ad78500441a52..1e519195d45bd1ab466f8b7ee12505f35a45d271 100644 (file)
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1710,3 +1710,39 @@ int __invalidate_device(struct block_device *bdev, bool kill_dirty)
        return res;
 }
 EXPORT_SYMBOL(__invalidate_device);
+
+void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg)
+{
+       struct inode *inode, *old_inode = NULL;
+
+       spin_lock(&inode_sb_list_lock);
+       list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) {
+               struct address_space *mapping = inode->i_mapping;
+
+               spin_lock(&inode->i_lock);
+               if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) ||
+                   mapping->nrpages == 0) {
+                       spin_unlock(&inode->i_lock);
+                       continue;
+               }
+               __iget(inode);
+               spin_unlock(&inode->i_lock);
+               spin_unlock(&inode_sb_list_lock);
+               /*
+                * We hold a reference to 'inode' so it couldn't have been
+                * removed from s_inodes list while we dropped the
+                * inode_sb_list_lock.  We cannot iput the inode now as we can
+                * be holding the last reference and we cannot iput it under
+                * inode_sb_list_lock. So we keep the reference and iput it
+                * later.
+                */
+               iput(old_inode);
+               old_inode = inode;
+
+               func(I_BDEV(inode), arg);
+
+               spin_lock(&inode_sb_list_lock);
+       }
+       spin_unlock(&inode_sb_list_lock);
+       iput(old_inode);
+}