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| author |   Sheng Yong <shengyong1@huawei.com> | 2018-11-14 19:34:28 +0800 |
|---|---|---|
| committer |   Jaegeuk Kim <jaegeuk@kernel.org> | 2018-11-26 15:53:57 -0800 |
| commit | 2866fb16d67992195b0526d19e65acb6640fb87f (patch) | |
| tree | bb74db858f11e02f127463e35fb26a639c4a7448 /fs/f2fs/data.c | |
| parent | f2fs: check memory boundary by insane namelen (diff) | |
| download | linux-dev-2866fb16d67992195b0526d19e65acb6640fb87f.tar.xz linux-dev-2866fb16d67992195b0526d19e65acb6640fb87f.zip | |
f2fs: fix race between write_checkpoint and write_begin
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>
Diffstat (limited to 'fs/f2fs/data.c')
| -rw-r--r-- | fs/f2fs/data.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 8aef1abc910a..8780f3d737c4 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2322,6 +2322,7 @@ 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 @@ -2331,9 +2332,15 @@ 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: @@ -2371,6 +2378,7 @@ 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; } @@ -2384,7 +2392,7 @@ 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; } |