summaryrefslogtreecommitdiffstats
path: root/fs/f2fs
diff options
context:
space:
mode:
authorChao Yu <yuchao0@huawei.com>2020-05-29 17:29:47 +0800
committerJaegeuk Kim <jaegeuk@kernel.org>2020-05-30 08:17:52 -0700
commitca7f76e680745d3b8a386638045f85dac1c4b2f4 (patch)
treec6889db95486ee70e3bee573a9dd4bff7136dc09 /fs/f2fs
parentdc35d73a42291b2a68f5b9a12b2b095b82194c1f (diff)
downloadlinux-ca7f76e680745d3b8a386638045f85dac1c4b2f4.tar.bz2
f2fs: fix wrong discard space
Under heavy fsstress, we may triggle panic while issuing discard, because __check_sit_bitmap() detects that discard command may earse valid data blocks, the root cause is as below race stack described, since we removed lock when flushing quota data, quota data writeback may race with write_checkpoint(), so that it causes inconsistency in between cached discard entry and segment bitmap. - f2fs_write_checkpoint - block_operations - set_sbi_flag(sbi, SBI_QUOTA_SKIP_FLUSH) - f2fs_flush_sit_entries - add_discard_addrs - __set_bit_le(i, (void *)de->discard_map); - f2fs_write_data_pages - f2fs_write_single_data_page : inode is quota one, cp_rwsem won't be locked - f2fs_do_write_data_page - f2fs_allocate_data_block - f2fs_wait_discard_bio : discard entry has not been added yet. - update_sit_entry - f2fs_clear_prefree_segments - f2fs_issue_discard : add discard entry In order to fix this, this patch uses node_write to serialize f2fs_allocate_data_block and checkpoint. Fixes: 435cbab95e39 ("f2fs: fix quota_sync failure due to f2fs_lock_op") Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs')
-rw-r--r--fs/f2fs/segment.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index ebbadde6cbce..196f31503511 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3107,6 +3107,14 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
type = CURSEG_COLD_DATA;
}
+ /*
+ * We need to wait for node_write to avoid block allocation during
+ * checkpoint. This can only happen to quota writes which can cause
+ * the below discard race condition.
+ */
+ if (IS_DATASEG(type))
+ down_write(&sbi->node_write);
+
down_read(&SM_I(sbi)->curseg_lock);
mutex_lock(&curseg->curseg_mutex);
@@ -3172,6 +3180,9 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
up_read(&SM_I(sbi)->curseg_lock);
+ if (IS_DATASEG(type))
+ up_write(&sbi->node_write);
+
if (put_pin_sem)
up_read(&sbi->pin_sem);
}