ocfs2: trylock in ocfs2_readpage()
Similarly to the page lock / cluster lock inversion in ocfs2_readpage, we
can deadlock on ip_alloc_sem. We can down_read_trylock() instead and just
return AOP_TRUNCATED_PAGE if the operation fails.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 8e7cafb5..3030670 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -222,7 +222,10 @@
goto out;
}
- down_read(&OCFS2_I(inode)->ip_alloc_sem);
+ if (down_read_trylock(&OCFS2_I(inode)->ip_alloc_sem) == 0) {
+ ret = AOP_TRUNCATED_PAGE;
+ goto out_meta_unlock;
+ }
/*
* i_size might have just been updated as we grabed the meta lock. We
@@ -258,6 +261,7 @@
ocfs2_data_unlock(inode, 0);
out_alloc:
up_read(&OCFS2_I(inode)->ip_alloc_sem);
+out_meta_unlock:
ocfs2_meta_unlock(inode, 0);
out:
if (unlock)