From: Chao Yu yuchao0@huawei.com
[ Upstream commit 3ab0598e6d860ef49d029943ba80f627c15c15d6 ]
f2fs_resize_fs() hangs in below callstack with testcase: - mkfs 16GB image & mount image - dd 8GB fileA - dd 8GB fileB - sync - rm fileA - sync - resize filesystem to 8GB
kernel BUG at segment.c:2484! Call Trace: allocate_segment_by_default+0x92/0xf0 [f2fs] f2fs_allocate_data_block+0x44b/0x7e0 [f2fs] do_write_page+0x5a/0x110 [f2fs] f2fs_outplace_write_data+0x55/0x100 [f2fs] f2fs_do_write_data_page+0x392/0x850 [f2fs] move_data_page+0x233/0x320 [f2fs] do_garbage_collect+0x14d9/0x1660 [f2fs] free_segment_range+0x1f7/0x310 [f2fs] f2fs_resize_fs+0x118/0x330 [f2fs] __f2fs_ioctl+0x487/0x3680 [f2fs] __x64_sys_ioctl+0x8e/0xd0 do_syscall_64+0x33/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xa9
The root cause is we forgot to check that whether we have enough space in resized filesystem to store all valid blocks in before-resizing filesystem, then allocator will run out-of-space during block migration in free_segment_range().
Fixes: b4b10061ef98 ("f2fs: refactor resize_fs to avoid meta updates in progress") Signed-off-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/f2fs/gc.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index b3af76340026..86ba8ed0b8a7 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -1977,7 +1977,20 @@ int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count)
/* stop CP to protect MAIN_SEC in free_segment_range */ f2fs_lock_op(sbi); + + spin_lock(&sbi->stat_lock); + if (shrunk_blocks + valid_user_blocks(sbi) + + sbi->current_reserved_blocks + sbi->unusable_block_count + + F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count) + err = -ENOSPC; + spin_unlock(&sbi->stat_lock); + + if (err) + goto out_unlock; + err = free_segment_range(sbi, secs, true); + +out_unlock: f2fs_unlock_op(sbi); up_write(&sbi->gc_lock); if (err)