From e76edab7f059bc1047c1865141e2709d70e74852 Mon Sep 17 00:00:00 2001 From: Elena Reshetova Date: Fri, 3 Mar 2017 10:55:13 +0200 Subject: [PATCH] btrfs: convert btrfs_ordered_extent.refs from atomic_t to refcount_t refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor Signed-off-by: David Sterba --- fs/btrfs/ordered-data.c | 18 +++++++++--------- fs/btrfs/ordered-data.h | 2 +- include/trace/events/btrfs.h | 2 +- 3 files changed, 11 insertions(+), 11 deletions(-) diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c index da5399f9fb54..7b40e2e7292a 100644 --- a/fs/btrfs/ordered-data.c +++ b/fs/btrfs/ordered-data.c @@ -212,7 +212,7 @@ static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset, set_bit(BTRFS_ORDERED_DIRECT, &entry->flags); /* one ref for the tree */ - atomic_set(&entry->refs, 1); + refcount_set(&entry->refs, 1); init_waitqueue_head(&entry->wait); INIT_LIST_HEAD(&entry->list); INIT_LIST_HEAD(&entry->root_extent_list); @@ -358,7 +358,7 @@ int btrfs_dec_test_first_ordered_pending(struct inode *inode, out: if (!ret && cached && entry) { *cached = entry; - atomic_inc(&entry->refs); + refcount_inc(&entry->refs); } spin_unlock_irqrestore(&tree->lock, flags); return ret == 0; @@ -425,7 +425,7 @@ have_entry: out: if (!ret && cached && entry) { *cached = entry; - atomic_inc(&entry->refs); + refcount_inc(&entry->refs); } spin_unlock_irqrestore(&tree->lock, flags); return ret == 0; @@ -456,7 +456,7 @@ void btrfs_get_logged_extents(struct btrfs_inode *inode, if (test_and_set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags)) continue; list_add(&ordered->log_list, logged_list); - atomic_inc(&ordered->refs); + refcount_inc(&ordered->refs); } spin_unlock_irq(&tree->lock); } @@ -565,7 +565,7 @@ void btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry) trace_btrfs_ordered_extent_put(entry->inode, entry); - if (atomic_dec_and_test(&entry->refs)) { + if (refcount_dec_and_test(&entry->refs)) { ASSERT(list_empty(&entry->log_list)); ASSERT(list_empty(&entry->trans_list)); ASSERT(list_empty(&entry->root_extent_list)); @@ -690,7 +690,7 @@ int btrfs_wait_ordered_extents(struct btrfs_root *root, int nr, list_move_tail(&ordered->root_extent_list, &root->ordered_extents); - atomic_inc(&ordered->refs); + refcount_inc(&ordered->refs); spin_unlock(&root->ordered_extent_lock); btrfs_init_work(&ordered->flush_work, @@ -870,7 +870,7 @@ struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode, if (!offset_in_entry(entry, file_offset)) entry = NULL; if (entry) - atomic_inc(&entry->refs); + refcount_inc(&entry->refs); out: spin_unlock_irq(&tree->lock); return entry; @@ -911,7 +911,7 @@ struct btrfs_ordered_extent *btrfs_lookup_ordered_range( } out: if (entry) - atomic_inc(&entry->refs); + refcount_inc(&entry->refs); spin_unlock_irq(&tree->lock); return entry; } @@ -948,7 +948,7 @@ btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset) goto out; entry = rb_entry(node, struct btrfs_ordered_extent, rb_node); - atomic_inc(&entry->refs); + refcount_inc(&entry->refs); out: spin_unlock_irq(&tree->lock); return entry; diff --git a/fs/btrfs/ordered-data.h b/fs/btrfs/ordered-data.h index 195c93b67fe0..e0c1d5b8d859 100644 --- a/fs/btrfs/ordered-data.h +++ b/fs/btrfs/ordered-data.h @@ -113,7 +113,7 @@ struct btrfs_ordered_extent { int compress_type; /* reference count */ - atomic_t refs; + refcount_t refs; /* the inode we belong to */ struct inode *inode; diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h index 9dd29e806fed..8f206263fee7 100644 --- a/include/trace/events/btrfs.h +++ b/include/trace/events/btrfs.h @@ -275,7 +275,7 @@ DECLARE_EVENT_CLASS(btrfs__ordered_extent, __entry->bytes_left = ordered->bytes_left; __entry->flags = ordered->flags; __entry->compress_type = ordered->compress_type; - __entry->refs = atomic_read(&ordered->refs); + __entry->refs = refcount_read(&ordered->refs); __entry->root_objectid = BTRFS_I(inode)->root->root_key.objectid; __entry->truncated_len = ordered->truncated_len; -- 2.20.1