blob: 46c73ee7e870bc9a35eaa0542e5963b994e8bb08 [file] [log] [blame]
From aff5121b9fa34b4785ef1903ab2f969e7f32cbca Mon Sep 17 00:00:00 2001
From: Jaegeuk Kim <jaegeuk@kernel.org>
Date: Tue, 3 Dec 2019 15:53:16 -0800
Subject: [PATCH] f2fs: call f2fs_balance_fs outside of locked page
commit bdf03299248916640a835a05d32841bb3d31912d upstream.
Otherwise, we can hit deadlock by waiting for the locked page in
move_data_block in GC.
Thread A Thread B
- do_page_mkwrite
- f2fs_vm_page_mkwrite
- lock_page
- f2fs_balance_fs
- mutex_lock(gc_mutex)
- f2fs_gc
- do_garbage_collect
- ra_data_block
- grab_cache_page
- f2fs_balance_fs
- mutex_lock(gc_mutex)
Fixes: 39a8695824510 ("f2fs: refactor ->page_mkwrite() flow")
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 3d4ec1615bfa..bffdca9a10d6 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -49,7 +49,7 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
struct page *page = vmf->page;
struct inode *inode = file_inode(vmf->vma->vm_file);
struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
- struct dnode_of_data dn = { .node_changed = false };
+ struct dnode_of_data dn;
int err;
if (unlikely(f2fs_cp_error(sbi))) {
@@ -57,6 +57,9 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
goto err;
}
+ /* should do out of any locked page */
+ f2fs_balance_fs(sbi, true);
+
sb_start_pagefault(inode->i_sb);
f2fs_bug_on(sbi, f2fs_has_inline_data(inode));
@@ -114,8 +117,6 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault *vmf)
out_sem:
up_read(&F2FS_I(inode)->i_mmap_sem);
- f2fs_balance_fs(sbi, dn.node_changed);
-
sb_end_pagefault(inode->i_sb);
err:
return block_page_mkwrite_return(err);
--
2.7.4