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path: root/fs/cifs/cifsfs.c
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Diffstat (limited to 'fs/cifs/cifsfs.c')
-rw-r--r--fs/cifs/cifsfs.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index b3a2a409710d..25bb97fc0d54 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -90,6 +90,30 @@ extern mempool_t *cifs_sm_req_poolp;
extern mempool_t *cifs_req_poolp;
extern mempool_t *cifs_mid_poolp;
+/*
+ * Bumps refcount for cifs super block.
+ * Note that it should be only called if a referece to VFS super block is
+ * already held, e.g. in open-type syscalls context. Otherwise it can race with
+ * atomic_dec_and_test in deactivate_locked_super.
+ */
+void
+cifs_sb_active(struct super_block *sb)
+{
+ struct cifs_sb_info *server = CIFS_SB(sb);
+
+ if (atomic_inc_return(&server->active) == 1)
+ atomic_inc(&sb->s_active);
+}
+
+void
+cifs_sb_deactive(struct super_block *sb)
+{
+ struct cifs_sb_info *server = CIFS_SB(sb);
+
+ if (atomic_dec_and_test(&server->active))
+ deactivate_super(sb);
+}
+
static int
cifs_read_super(struct super_block *sb)
{