It is better to iterate over all_bdevs list in iterate_bdevs() because
inode list of blockdev_super contains also inodes which are not describing
any block device (e.g. root of bdev filesystem).
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/block_dev.c | 45 +++++++++++++++++++++++++--------------------
1 files changed, 25 insertions(+), 20 deletions(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 38e721b..220391c 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1716,36 +1716,41 @@ 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;
+ struct block_device *bdev, *old_bdev = NULL;
+ struct inode *inode;
+ spin_lock(&bdev_lock);
+ list_for_each_entry(bdev, &all_bdevs, bd_list) {
+ inode = bdev->bd_inode;
spin_lock(&inode->i_lock);
+ /*
+ * With i_lock we can safely check bdev isn't freeing and
+ * grab our reference.
+ */
if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) ||
- mapping->nrpages == 0) {
+ inode->i_mapping->nrpages == 0) {
spin_unlock(&inode->i_lock);
continue;
}
- __iget(inode);
+ bdgrab(bdev);
spin_unlock(&inode->i_lock);
- spin_unlock(&inode_sb_list_lock);
+ spin_unlock(&bdev_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.
+ * We hold a reference to 'bdev' so it couldn't have been
+ * removed from the list while we dropped the bdev_lock. We
+ * cannot put the reference now as we can be holding the last
+ * reference and we cannot put it under bdev_lock. So we keep
+ * the reference and put it later.
*/
- iput(old_inode);
- old_inode = inode;
+ if (old_bdev)
+ bdput(old_bdev);
+ old_bdev = bdev;
- func(I_BDEV(inode), arg);
+ func(bdev, arg);
- spin_lock(&inode_sb_list_lock);
+ spin_lock(&bdev_lock);
}
- spin_unlock(&inode_sb_list_lock);
- iput(old_inode);
+ spin_unlock(&bdev_lock);
+ if (old_bdev)
+ bdput(old_bdev);
}
--
1.7.1
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