Re: WARNING in ext4_set_page_dirty

[Theodore Ts'o]

#syz dup: WARNING in ext4_dirty_folio
#syz set subsystems: mm

ext4_set_page_dirty() was renamed to ext4_dirty_folio() in commit
e621900ad28b ("fs: Convert __set_page_dirty_buffers to
block_dirty_folio") in February 2022 --- which explains why it hasn't
reproduced in over 400 days,

(I assume marking it is the right thing to do, although the syzkaller
documentation doesn't explain exactly what happens after you mark the
report as a dup.  The other possibility would be to marking it as
invalid, to drop this as noise.  But that feels wrong, so I'm guessing
marking it as a dup is the best way to handle this kind of situation.)

I'm moving this to the mm subsystem, since the root cause is the
get_user_pages issue that has been with us for years, with discussions
as early as the 2018 LSF/MM.

					- Ted