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authorElena Reshetova <elena.reshetova@intel.com>2017-03-03 10:55:18 +0200
committerDavid Sterba <dsterba@suse.com>2017-04-18 14:07:23 +0200
commit0700cea7c8b387c8c6bc4de79b197baa0b3fc4a3 (patch)
tree7bec132f997899bc7000ed108d539067438fd21f /fs
parent089e77e10d7e44a007101cf7323dc7bda66172f4 (diff)
downloadtalos-obmc-linux-0700cea7c8b387c8c6bc4de79b197baa0b3fc4a3.tar.gz
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btrfs: convert btrfs_root.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 <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/ctree.h2
-rw-r--r--fs/btrfs/disk-io.c2
-rw-r--r--fs/btrfs/disk-io.h4
3 files changed, 4 insertions, 4 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index cdfc2a46448b..285566cc2f7d 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1222,7 +1222,7 @@ struct btrfs_root {
dev_t anon_dev;
spinlock_t root_item_lock;
- atomic_t refs;
+ refcount_t refs;
struct mutex delalloc_mutex;
spinlock_t delalloc_lock;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 3748bc54a6ab..bd415e1dd114 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -1340,7 +1340,7 @@ static void __setup_root(struct btrfs_root *root, struct btrfs_fs_info *fs_info,
atomic_set(&root->log_writers, 0);
atomic_set(&root->log_batch, 0);
atomic_set(&root->orphan_inodes, 0);
- atomic_set(&root->refs, 1);
+ refcount_set(&root->refs, 1);
atomic_set(&root->will_be_snapshoted, 0);
atomic64_set(&root->qgroup_meta_rsv, 0);
root->log_transid = 0;
diff --git a/fs/btrfs/disk-io.h b/fs/btrfs/disk-io.h
index 2e0ec29bfd69..21f1ceb85b76 100644
--- a/fs/btrfs/disk-io.h
+++ b/fs/btrfs/disk-io.h
@@ -101,14 +101,14 @@ struct btrfs_root *btrfs_alloc_dummy_root(struct btrfs_fs_info *fs_info);
*/
static inline struct btrfs_root *btrfs_grab_fs_root(struct btrfs_root *root)
{
- if (atomic_inc_not_zero(&root->refs))
+ if (refcount_inc_not_zero(&root->refs))
return root;
return NULL;
}
static inline void btrfs_put_fs_root(struct btrfs_root *root)
{
- if (atomic_dec_and_test(&root->refs))
+ if (refcount_dec_and_test(&root->refs))
kfree(root);
}
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