Re: [PATCH 4.19 29/71] btrfs: tree-checker: Verify inode item

From: Pavel Machek
Date: Wed Nov 11 2020 - 08:39:07 EST


Hi!

> >> From: Qu Wenruo <wqu@xxxxxxxx>
> >>
> >> commit 496245cac57e26d8b738d85c7a29cf9a47610f3f upstream.
> >>
> >> There is a report in kernel bugzilla about mismatch file type in dir
> >> item and inode item.
> >>
> >> This inspires us to check inode mode in inode item.
> >>
> >> This patch will check the following members:
> >
> >> + /* Here we use super block generation + 1 to handle log tree */
> >> + if (btrfs_inode_generation(leaf, iitem) > super_gen + 1) {
> >> + inode_item_err(fs_info, leaf, slot,
> >> + "invalid inode generation: has %llu expect (0, %llu]",
> >> + btrfs_inode_generation(leaf, iitem),
> >> + super_gen + 1);
> >> + return -EUCLEAN;
> >> + }
> >
> > Printk suggests btrfs_inode_generation() may not be zero, but the
> > condition does not actually check that. Should that be added?
>
> Sorry, btrfs_inode_generation() here is exactly what we're checking
> here, so what's wrong?

Quoted message says "(0, ...]", while message below says "[0, ...]". I
assume that means that btrfs_inode_generation() may not be zero in the
first case, but may be zero in the second case. But the code does not
test for zero here.

Best regards,
Pavel

> >> + /* Note for ROOT_TREE_DIR_ITEM, mkfs could set its transid 0 */
> >> + if (btrfs_inode_transid(leaf, iitem) > super_gen + 1) {
> >> + inode_item_err(fs_info, leaf, slot,
> >> + "invalid inode generation: has %llu expect [0, %llu]",
> >> + btrfs_inode_transid(leaf, iitem), super_gen + 1);
> >> + return -EUCLEAN;
> >> + }

--
http://www.livejournal.com/~pavelmachek

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