4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 2866fb16d67992195b0526d19e65acb6640fb87f ]
The following race could lead to inconsistent SIT bitmap:
Task A Task B ====== ====== f2fs_write_checkpoint block_operations f2fs_lock_all down_write(node_change) down_write(node_write) ... sync ... up_write(node_change) f2fs_file_write_iter set_inode_flag(FI_NO_PREALLOC) ...... f2fs_write_begin(index=0, has inline data) prepare_write_begin __do_map_lock(AIO) => down_read(node_change) f2fs_convert_inline_page => update SIT __do_map_lock(AIO) => up_read(node_change) f2fs_flush_sit_entries <= inconsistent SIT finish write checkpoint sudden-power-off
If SPO occurs after checkpoint is finished, SIT bitmap will be set incorrectly.
Signed-off-by: Sheng Yong shengyong1@huawei.com Reviewed-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/f2fs/data.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 17049b030b6c..e90ca6aa3a00 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2326,6 +2326,7 @@ static int prepare_write_begin(struct f2fs_sb_info *sbi, bool locked = false; struct extent_info ei = {0,0,0}; int err = 0; + int flag;
/* * we already allocated all the blocks, so we don't need to get @@ -2335,9 +2336,15 @@ static int prepare_write_begin(struct f2fs_sb_info *sbi, !is_inode_flag_set(inode, FI_NO_PREALLOC)) return 0;
+ /* f2fs_lock_op avoids race between write CP and convert_inline_page */ + if (f2fs_has_inline_data(inode) && pos + len > MAX_INLINE_DATA(inode)) + flag = F2FS_GET_BLOCK_DEFAULT; + else + flag = F2FS_GET_BLOCK_PRE_AIO; + if (f2fs_has_inline_data(inode) || (pos & PAGE_MASK) >= i_size_read(inode)) { - __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, true); + __do_map_lock(sbi, flag, true); locked = true; } restart: @@ -2375,6 +2382,7 @@ restart: f2fs_put_dnode(&dn); __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, true); + WARN_ON(flag != F2FS_GET_BLOCK_PRE_AIO); locked = true; goto restart; } @@ -2388,7 +2396,7 @@ out: f2fs_put_dnode(&dn); unlock_out: if (locked) - __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, false); + __do_map_lock(sbi, flag, false); return err; }