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authorSheng Yong <shengyong1@huawei.com>2018-11-14 19:34:28 +0800
committerJaegeuk Kim <jaegeuk@kernel.org>2018-11-26 15:53:57 -0800
commit2866fb16d67992195b0526d19e65acb6640fb87f (patch)
treebb74db858f11e02f127463e35fb26a639c4a7448 /fs/f2fs
parent4e240d1bab1ead280ddf5eb05058dba6bbd57d10 (diff)
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')
-rw-r--r--fs/f2fs/data.c12
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;
}