Hi Jaeguek, On 2019/12/6 12:08, Jaegeuk Kim wrote: > Hi Chao, > > I was testing this. > > https://github.com/jaegeuk/f2fs/commit/76be33b9f1fce70dd2d3f04f66d0f78b418fe3f5
The patch looks good. BTW, do you mind adding below call stack into your patch? I guess it describes this ABBA deadlock with more details. :) Thanks, > > On 12/06, Chao Yu wrote: >> As Dinosaur Huang reported, there is a potential deadlock in between >> GC and mkwrite(): >> >> 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) >> >> In order to fix this, we just move f2fs_balance_fs() out of page lock's >> coverage in f2fs_vm_page_mkwrite(). >> >> Reported-by: Dinosaur Huang <dinosaur.hu...@unisoc.com> >> Signed-off-by: Chao Yu <yuch...@huawei.com> >> --- >> fs/f2fs/file.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c >> index c0560d62dbee..ed3290225506 100644 >> --- a/fs/f2fs/file.c >> +++ b/fs/f2fs/file.c >> @@ -67,6 +67,8 @@ static vm_fault_t f2fs_vm_page_mkwrite(struct vm_fault >> *vmf) >> >> f2fs_bug_on(sbi, f2fs_has_inline_data(inode)); >> >> + f2fs_balance_fs(sbi, true); >> + >> file_update_time(vmf->vma->vm_file); >> down_read(&F2FS_I(inode)->i_mmap_sem); >> lock_page(page); >> @@ -120,8 +122,6 @@ 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); >> -- >> 2.18.0.rc1 > . > _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
