From 13b546d96207c131eeae15dc7b26c6e7d0f1cad7 Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Wed, 12 Feb 2014 12:44:56 -0800 Subject: [PATCH] jffs2: avoid soft-lockup in jffs2_reserve_space_gc() We triggered soft-lockup under stress test on 2.6.34 kernel. BUG: soft lockup - CPU#1 stuck for 60009ms! [lockf2.test:14488] ... [] (jffs2_do_reserve_space+0x420/0x440 [jffs2]) [] (jffs2_reserve_space_gc+0x34/0x78 [jffs2]) [] (jffs2_garbage_collect_dnode.isra.3+0x264/0x478 [jffs2]) [] (jffs2_garbage_collect_pass+0x9c0/0xe4c [jffs2]) [] (jffs2_reserve_space+0x104/0x2a8 [jffs2]) [] (jffs2_write_inode_range+0x5c/0x4d4 [jffs2]) [] (jffs2_write_end+0x198/0x2c0 [jffs2]) [] (generic_file_buffered_write+0x158/0x200) [] (__generic_file_aio_write+0x3a4/0x414) [] (generic_file_aio_write+0x5c/0xbc) [] (do_sync_write+0x98/0xd4) [] (vfs_write+0xa8/0x150) [] (sys_write+0x3c/0xc0)] Fix this by adding a cond_resched() in the while loop. [akpm@linux-foundation.org: don't initialize `ret'] Signed-off-by: Li Zefan Cc: David Woodhouse Cc: Artem Bityutskiy Cc: Signed-off-by: Andrew Morton Signed-off-by: Brian Norris --- fs/jffs2/nodemgmt.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/fs/jffs2/nodemgmt.c b/fs/jffs2/nodemgmt.c index bbae5b1a833a..b6bd4affd9ad 100644 --- a/fs/jffs2/nodemgmt.c +++ b/fs/jffs2/nodemgmt.c @@ -212,20 +212,25 @@ out: int jffs2_reserve_space_gc(struct jffs2_sb_info *c, uint32_t minsize, uint32_t *len, uint32_t sumsize) { - int ret = -EAGAIN; + int ret; minsize = PAD(minsize); jffs2_dbg(1, "%s(): Requested 0x%x bytes\n", __func__, minsize); - spin_lock(&c->erase_completion_lock); - while(ret == -EAGAIN) { + while (true) { + spin_lock(&c->erase_completion_lock); ret = jffs2_do_reserve_space(c, minsize, len, sumsize); if (ret) { jffs2_dbg(1, "%s(): looping, ret is %d\n", __func__, ret); } + spin_unlock(&c->erase_completion_lock); + + if (ret == -EAGAIN) + cond_resched(); + else + break; } - spin_unlock(&c->erase_completion_lock); if (!ret) ret = jffs2_prealloc_raw_node_refs(c, c->nextblock, 1); -- 2.34.1