diff options
| author | KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> | 2014-02-06 12:04:28 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-20 11:10:09 -0800 |
| commit | ca3b5b2dfbe20de81ede6b95cd21ca4ebed272ea (patch) | |
| tree | 828d7eda6e3f07063547f753771b5fac218afc10 | |
| parent | 27b4328e523b3de854229e6b505f94aa9708dde6 (diff) | |
mm: __set_page_dirty uses spin_lock_irqsave instead of spin_lock_irq
commit 227d53b397a32a7614667b3ecaf1d89902fb6c12 upstream.
To use spin_{un}lock_irq is dangerous if caller disabled interrupt.
During aio buffer migration, we have a possibility to see the following
call stack.
aio_migratepage [disable interrupt]
migrate_page_copy
clear_page_dirty_for_io
set_page_dirty
__set_page_dirty_buffers
__set_page_dirty
spin_lock_irq
This mean, current aio migration is a deadlockable. spin_lock_irqsave
is a safer alternative and we should use it.
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: David Rientjes rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/buffer.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index 6024877335c..aeeea6529bc 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -654,14 +654,16 @@ EXPORT_SYMBOL(mark_buffer_dirty_inode); static void __set_page_dirty(struct page *page, struct address_space *mapping, int warn) { - spin_lock_irq(&mapping->tree_lock); + unsigned long flags; + + spin_lock_irqsave(&mapping->tree_lock, flags); if (page->mapping) { /* Race with truncate? */ WARN_ON_ONCE(warn && !PageUptodate(page)); account_page_dirtied(page, mapping); radix_tree_tag_set(&mapping->page_tree, page_index(page), PAGECACHE_TAG_DIRTY); } - spin_unlock_irq(&mapping->tree_lock); + spin_unlock_irqrestore(&mapping->tree_lock, flags); __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); } |