Messages in this thread |  | | Subject | Re: [PATCH] ubifs: Fix a potential space leak problem while linking tmpfile | From | Zhihao Cheng <> | Date | Mon, 13 Jul 2020 11:30:09 +0800 |
| |
在 2020/7/11 14:37, Zhihao Cheng 写道: > 在 2020/7/7 20:47, Richard Weinberger 写道: >> ----- Ursprüngliche Mail ----- >>>>> Perhaps I misunderstood what commit 32fe905c17f001 ("ubifs: Fix >>>>> O_TMPFILE corner case in ubifs_link()") wanted to fix. >>>>> I think orphan area is used to remind filesystem don't forget to >>>>> delete >>>>> inodes (whose nlink is 0) in next unclean rebooting. Generally, >>>>> the file >>>>> system is not corrupted caused by replaying orphan nodes. >>>>> Ralph reported a filesystem corruption in combination with overlayfs. >>>>> Can you tell me the details about that problem? Thanks. >>>> On my test bed I didn't see a fs corruption, what I saw was a >>>> failing orphan >>>> self test while playing with O_TMPFILE and linkat(). >>> Do we have a reproducer, or can I get the fail testcase? Is it a >>> xfstest >>> case? >> I think xfstests triggered it, yes. >> Later today I can check. :) >> >> Thanks, >> //richard >> >> . > > I think I have found the testcases, overlay/006 and overlay/041. > > The 'mv' and 'rm' operations will put lowertestfile into orphan list > twice, so we must reseve the orphan deletion operation in > ubifs_link(), otherwise the testcase fails and we will see the > following msg: Sorry, not lowertestfile, it's tempfile which is generated by ovl copy-up (mv operation). The tempfile is linked after copy-up finished. The tempfile is then unlinked by 'rm' operation. > > overlay/006 2s ... - output mismatch (see > /root/git/xfstests-dev/results//overlay/006.out.bad) > --- tests/overlay/006.out 2020-07-07 21:42:57.737000000 +0800 > +++ /root/git/xfstests-dev/results//overlay/006.out.bad 2020-07-11 > 14:31:55.340000000 +0800 > @@ -1,2 +1,4 @@ > QA output created by 006 > Silence is golden > +rm: cannot remove > '/tmp/scratch/ovl-mnt/uppertestdir/lowertestfile': Invalid argument > +lowertestfile > ... > > [ 382.258210] UBIFS error (ubi0:1 pid 11896): orphan_add [ubifs]: > orphaned twice > [ 382.352535] UBIFS error (ubi0:1 pid 11930): free_orphans [ubifs]: > orphan list not empty at unmount > > > So, how about moving ubifs_delete_orphan() after ubifs_jnl_update() in > function ubifs_link(). Following modifications applied in linux-5.8 > has been tested by overlay/041, overlay/006 and other tmpfile cases > (generic/531, generic/530, generic/509, generic/389, generic/004). > > diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c > index ef85ec167a84..fd4443a5e8c6 100644 > --- a/fs/ubifs/dir.c > +++ b/fs/ubifs/dir.c > @@ -722,11 +722,6 @@ static int ubifs_link(struct dentry *old_dentry, > struct inode *dir, > goto out_fname; > > lock_2_inodes(dir, inode); > - > - /* Handle O_TMPFILE corner case, it is allowed to link a > O_TMPFILE. */ > - if (inode->i_nlink == 0) > - ubifs_delete_orphan(c, inode->i_ino); > - > inc_nlink(inode); > ihold(inode); > inode->i_ctime = current_time(inode); > @@ -736,6 +731,11 @@ static int ubifs_link(struct dentry *old_dentry, > struct inode *dir, > err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0); > if (err) > goto out_cancel; > + > + /* Handle O_TMPFILE corner case, it is allowed to link a > O_TMPFILE. */ > + if (inode->i_nlink == 1) > + ubifs_delete_orphan(c, inode->i_ino); > + > unlock_2_inodes(dir, inode); > > ubifs_release_budget(c, &req); > @@ -747,8 +747,6 @@ static int ubifs_link(struct dentry *old_dentry, > struct inode *dir, > dir->i_size -= sz_change; > dir_ui->ui_size = dir->i_size; > drop_nlink(inode); > - if (inode->i_nlink == 0) > - ubifs_add_orphan(c, inode->i_ino); > unlock_2_inodes(dir, inode); > ubifs_release_budget(c, &req); > iput(inode); > -- > > > > ______________________________________________________ > Linux MTD discussion mailing list > http://lists.infradead.org/mailman/listinfo/linux-mtd/
|  |