| From 13b546d96207c131eeae15dc7b26c6e7d0f1cad7 Mon Sep 17 00:00:00 2001 |
| From: Li Zefan <lizefan@huawei.com> |
| Date: Wed, 12 Feb 2014 12:44:56 -0800 |
| Subject: jffs2: avoid soft-lockup in jffs2_reserve_space_gc() |
| |
| From: Li Zefan <lizefan@huawei.com> |
| |
| commit 13b546d96207c131eeae15dc7b26c6e7d0f1cad7 upstream. |
| |
| We triggered soft-lockup under stress test on 2.6.34 kernel. |
| |
| BUG: soft lockup - CPU#1 stuck for 60009ms! [lockf2.test:14488] |
| ... |
| [<bf09a4d4>] (jffs2_do_reserve_space+0x420/0x440 [jffs2]) |
| [<bf09a528>] (jffs2_reserve_space_gc+0x34/0x78 [jffs2]) |
| [<bf0a1350>] (jffs2_garbage_collect_dnode.isra.3+0x264/0x478 [jffs2]) |
| [<bf0a2078>] (jffs2_garbage_collect_pass+0x9c0/0xe4c [jffs2]) |
| [<bf09a670>] (jffs2_reserve_space+0x104/0x2a8 [jffs2]) |
| [<bf09dc48>] (jffs2_write_inode_range+0x5c/0x4d4 [jffs2]) |
| [<bf097d8c>] (jffs2_write_end+0x198/0x2c0 [jffs2]) |
| [<c00e00a4>] (generic_file_buffered_write+0x158/0x200) |
| [<c00e14f4>] (__generic_file_aio_write+0x3a4/0x414) |
| [<c00e15c0>] (generic_file_aio_write+0x5c/0xbc) |
| [<c012334c>] (do_sync_write+0x98/0xd4) |
| [<c0123a84>] (vfs_write+0xa8/0x150) |
| [<c0123d74>] (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 <lizefan@huawei.com> |
| Cc: David Woodhouse <dwmw2@infradead.org> |
| Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Brian Norris <computersforpeace@gmail.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| fs/jffs2/nodemgmt.c | 13 +++++++++---- |
| 1 file changed, 9 insertions(+), 4 deletions(-) |
| |
| --- a/fs/jffs2/nodemgmt.c |
| +++ b/fs/jffs2/nodemgmt.c |
| @@ -211,20 +211,25 @@ 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); |
| |