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I am having e-mail client issues, its messing up patches..=20 Once I fix them, I will resend the patch. Thanks, Badari -----Original Message----- From: SeongJae Park =20 Sent: Monday, August 15, 2022 4:42 PM To: Pulavarty, Badari Cc: SeongJae Park ; damon@lists.linux.dev; linux-mm@kvack.or= g Subject: RE: [PATCH] DAMON dbgfs_mk_context() error handling Hi Badari, On Mon, 15 Aug 2022 21:51:04 +0000 "Pulavarty, Badari" wrote: > [-- Attachment #1: Type: text/plain, Size: 350 bytes --] >=20 > Hi SI, >=20 > > Nice finding, thank you! But, the return value of the debugfs call=20 > > is intentionally ignored[2]. How about doing the duplicated name=20 > > check in > > dbgfs_mk_context() itself before the debugfs_create_dir() call? Please don't unwrap wrapped message. My monitor is not so wide :'( > > > > [2]=20 > > https://lore.kernel.org/linux-mm/20210205155902.31102-1-sjpark@amazo > > n.com/ >=20 > How about this? >=20 > Thanks, > Badari >=20 >=20 >=20 > [-- Attachment #2: damon-mkcontext-fix.patch --] > [-- Type: application/octet-stream, Size: 858 bytes --] Could you please don't send a patch as an attached file of the mail but put= it in the mail body so that we can easily read the patch and comment in li= ne? >=20 > damon dbgfs_mk_context() should check to make sure there is no=20 > existing context with the same name. Otherwise, it will cause failure=20 > when we enabling the monitor. >=20 > Test case: >=20 > echo "off" > /sys/kernel/debug/damon/monitor_on > echo "abc" > /sys/kernel/debug/damon/mk_context > echo "abc" > /sys/kernel/debug/damon/mk_context > echo > /sys/kernel/debug/damon/abc/target_ids > echo "on" > /sys/kernel/debug/damon/monitor_on <<< fails >=20 > Signed-off-by: Badari Pulavarty > --- It would be good to put the changelog of this patch here: https://docs.kernel.org/process/submitting-patches.html#the-canonical-patch= -format > --- a/mm/damon/dbgfs.c 2022-08-15 14:27:38.308806431 -0700 > +++ b/mm/damon/dbgfs.c 2022-08-15 14:33:31.661163048 -0700 > @@ -817,6 +817,12 @@ > if (!root) > return -ENOENT; > =20 > + new_dir =3D debugfs_lookup(name, root); > + if (new_dir) { > + dput(new_dir); > + return -EEXIST; > + } > + The change looks ok to me at a glance, but the attached file seems not an a= ppropriate patch. Could you please repost this as a formal patch as sugges= ted for a better review? Thanks, SJ > new_dir =3D debugfs_create_dir(name, root); > dbgfs_dirs[dbgfs_nr_ctxs] =3D new_dir;