Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/block_dev.c | 36 ++++++++++++++++++++++++++++++++++++
include/linux/fs.h | 1 +
2 files changed, 37 insertions(+), 0 deletions(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index b07f1da..4d6631e 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -196,6 +196,42 @@ blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
nr_segs, blkdev_get_blocks, NULL, NULL, 0);
}
+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);
+}
+
int __sync_blockdev(struct block_device *bdev, int wait)
{
if (!bdev)
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0c4df26..0404e7c 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2089,6 +2089,7 @@ extern void bd_set_size(struct block_device *, loff_t size);
extern void bd_forget(struct inode *inode);
extern void bdput(struct block_device *);
extern void invalidate_bdev(struct block_device *);
+extern void iterate_bdevs(void (*)(struct block_device *, void *), void *);
extern int sync_blockdev(struct block_device *bdev);
extern struct super_block *freeze_bdev(struct block_device *);
extern void emergency_thaw_all(void);
--
1.7.1
--
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