Messages in this thread | | | From | Daeho Jeong <> | Date | Fri, 8 May 2020 15:58:44 +0900 | Subject | Re: [f2fs-dev] [PATCH] f2fs: remove race condition in releasing cblocks |
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I moved checking i_compr_blocks phrase after calling inode_lock() already, because we should check this after writing pages.
So, if it fails to check i_compr_blocks, we need to call inode_unlock().
Am I missing something?
2020년 5월 8일 (금) 오후 3:50, Chao Yu <yuchao0@huawei.com>님이 작성: > > On 2020/5/8 12:25, Daeho Jeong wrote: > > From: Daeho Jeong <daehojeong@google.com> > > > > Now, if writing pages and releasing compress blocks occur > > simultaneously, and releasing cblocks is executed more than one time > > to a file, then total block count of filesystem and block count of the > > file could be incorrect and damaged. > > > > We have to execute releasing compress blocks only one time for a file > > without being interfered by writepages path. > > > > Signed-off-by: Daeho Jeong <daehojeong@google.com> > > --- > > fs/f2fs/file.c | 31 ++++++++++++++++++++++++------- > > 1 file changed, 24 insertions(+), 7 deletions(-) > > > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c > > index 4aab4b42d8ba..a92bc51b9b28 100644 > > --- a/fs/f2fs/file.c > > +++ b/fs/f2fs/file.c > > @@ -3488,6 +3488,7 @@ static int f2fs_release_compress_blocks(struct file *filp, unsigned long arg) > > pgoff_t page_idx = 0, last_idx; > > unsigned int released_blocks = 0; > > int ret; > > + int writecount; > > > > if (!f2fs_sb_has_compression(F2FS_I_SB(inode))) > > return -EOPNOTSUPP; > > Before inode_lock(), there is one case we may jump to out label, in > this case, we may unlock inode incorrectly. > > if (!F2FS_I(inode)->i_compr_blocks) > goto out; > > > - > > - inode_unlock(inode); > > out: > > + inode_unlock(inode); > > + > > mnt_drop_write_file(filp); > > Thanks,
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