f2fs: fix livelock calling f2fs_iget during f2fs_evict_inode
In f2fs_evict_inode,
commit_inmemory_pages
f2fs_gc
f2fs_iget
iget_locked
-> wait for inode free
Here, if the inode is same as the one to be evicted, f2fs should wait forever.
Actually, we should not call f2fs_balance_fs during f2fs_evict_inode to avoid
this.
But, the commit_inmem_pages calls f2fs_balance_fs by default, even if
f2fs_evict_inode wants to free inmemory pages only.
Hence, this patch adds to trigger f2fs_balance_fs only when there is something
to write.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 9de857f..9a33e34 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -230,7 +230,16 @@
.rw = WRITE_SYNC,
};
- f2fs_balance_fs(sbi);
+ /*
+ * The abort is true only when f2fs_evict_inode is called.
+ * Basically, the f2fs_evict_inode doesn't produce any data writes, so
+ * that we don't need to call f2fs_balance_fs.
+ * Otherwise, f2fs_gc in f2fs_balance_fs can wait forever until this
+ * inode becomes free by iget_locked in f2fs_iget.
+ */
+ if (!abort)
+ f2fs_balance_fs(sbi);
+
f2fs_lock_op(sbi);
mutex_lock(&fi->inmem_lock);