When there is no free cache buffers, we need to free some cache buffers
based on very simple algorithm for now, when deleting a file or unload
the blobfs, there must no dirty caches, there is no cache buffers after
calling spdk_tree_free_buffers(), so we will create another cache free
buffers function which only used in file read/write path.
When testing blobfs with db_bench, there maybe multiple threads will
call alloc_cache_memory_buffer() at same time, and spdk_fs_delete_file_async()
maybe called at same time, and it may release file->tree and file structure
without holding g_caches_lock, so here we will change the
alloc_cache_memory_buffer() to hold the g_caches_lock while releasing
the file cache buffers.
Fix issue #1133.
Change-Id: I115ff97113915630f539c3458c57116d9ff16179
Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/668
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
72b9af55fa