| Message ID | 1612165930-110076-1-git-send-email-jiapeng.chong@linux.alibaba.com |
|---|---|
| State | New |
| Headers | show |
| Series | ceph: Replace DEFINE_SIMPLE_ATTRIBUTE with DEFINE_DEBUGFS_ATTRIBUTE | expand |
On Mon, Feb 1, 2021 at 8:52 AM Jiapeng Chong <jiapeng.chong@linux.alibaba.com> wrote: > > Fix the following coccicheck warning: > > ./fs/ceph/debugfs.c:347:0-23: WARNING: congestion_kb_fops should be > defined with DEFINE_DEBUGFS_ATTRIBUTE. > > Reported-by: Abaci Robot <abaci@linux.alibaba.com> > Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> > --- > fs/ceph/debugfs.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c > index 66989c8..617327e 100644 > --- a/fs/ceph/debugfs.c > +++ b/fs/ceph/debugfs.c > @@ -344,8 +344,8 @@ static int congestion_kb_get(void *data, u64 *val) > return 0; > } > > -DEFINE_SIMPLE_ATTRIBUTE(congestion_kb_fops, congestion_kb_get, > - congestion_kb_set, "%llu\n"); > +DEFINE_DEBUGFS_ATTRIBUTE(congestion_kb_fops, congestion_kb_get, > + congestion_kb_set, "%llu\n"); > > > void ceph_fs_debugfs_cleanup(struct ceph_fs_client *fsc) Hi Jiapeng, What is the benefit of this conversion? From a quick look, with DEFINE_DEBUGFS_ATTRIBUTE writeback_congestion_kb file would no longer be seekable. It may not matter much, but something that should have been mentioned. Futher, debugfs_create_file() creates a full proxy for fops, protecting against removal races. DEFINE_DEBUGFS_ATTRIBUTE adds its own protection but just for ->read() and ->write(). I don't think we need both. Thanks, Ilya
On Tue, 2021-02-02 at 13:07 +0100, Ilya Dryomov wrote: > On Mon, Feb 1, 2021 at 8:52 AM Jiapeng Chong > <jiapeng.chong@linux.alibaba.com> wrote: > > > > Fix the following coccicheck warning: > > > > ./fs/ceph/debugfs.c:347:0-23: WARNING: congestion_kb_fops should be > > defined with DEFINE_DEBUGFS_ATTRIBUTE. > > > > Reported-by: Abaci Robot <abaci@linux.alibaba.com> > > Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> > > --- > > fs/ceph/debugfs.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c > > index 66989c8..617327e 100644 > > --- a/fs/ceph/debugfs.c > > +++ b/fs/ceph/debugfs.c > > @@ -344,8 +344,8 @@ static int congestion_kb_get(void *data, u64 *val) > > return 0; > > } > > > > -DEFINE_SIMPLE_ATTRIBUTE(congestion_kb_fops, congestion_kb_get, > > - congestion_kb_set, "%llu\n"); > > +DEFINE_DEBUGFS_ATTRIBUTE(congestion_kb_fops, congestion_kb_get, > > + congestion_kb_set, "%llu\n"); > > > > > > void ceph_fs_debugfs_cleanup(struct ceph_fs_client *fsc) > > Hi Jiapeng, > > What is the benefit of this conversion? > > From a quick look, with DEFINE_DEBUGFS_ATTRIBUTE writeback_congestion_kb > file would no longer be seekable. It may not matter much, but something > that should have been mentioned. > > Futher, debugfs_create_file() creates a full proxy for fops, protecting > against removal races. DEFINE_DEBUGFS_ATTRIBUTE adds its own protection > but just for ->read() and ->write(). I don't think we need both. > The coccinelle script clarifies some of this. See the commit log here: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5103068eaca290f890a30aae70085fac44cecaf6 That said, it also mentions that the file should be converted to use debugfs_create_file_unsafe now as well, and that wasn't done in this patch. Jiapeng, was that intentional? If so, why? -- Jeff Layton <jlayton@kernel.org>
On Tue, 2021-02-02 at 07:45 -0500, Jeff Layton wrote: > On Tue, 2021-02-02 at 13:07 +0100, Ilya Dryomov wrote: > > On Mon, Feb 1, 2021 at 8:52 AM Jiapeng Chong > > <jiapeng.chong@linux.alibaba.com> wrote: > > > > > > Fix the following coccicheck warning: > > > > > > ./fs/ceph/debugfs.c:347:0-23: WARNING: congestion_kb_fops should be > > > defined with DEFINE_DEBUGFS_ATTRIBUTE. > > > > > > Reported-by: Abaci Robot <abaci@linux.alibaba.com> > > > Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> > > > --- > > > fs/ceph/debugfs.c | 4 ++-- > > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > > > diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c > > > index 66989c8..617327e 100644 > > > --- a/fs/ceph/debugfs.c > > > +++ b/fs/ceph/debugfs.c > > > @@ -344,8 +344,8 @@ static int congestion_kb_get(void *data, u64 *val) > > > return 0; > > > } > > > > > > -DEFINE_SIMPLE_ATTRIBUTE(congestion_kb_fops, congestion_kb_get, > > > - congestion_kb_set, "%llu\n"); > > > +DEFINE_DEBUGFS_ATTRIBUTE(congestion_kb_fops, congestion_kb_get, > > > + congestion_kb_set, "%llu\n"); > > > > > > > > > void ceph_fs_debugfs_cleanup(struct ceph_fs_client *fsc) > > > > Hi Jiapeng, > > > > What is the benefit of this conversion? > > > > From a quick look, with DEFINE_DEBUGFS_ATTRIBUTE writeback_congestion_kb > > file would no longer be seekable. It may not matter much, but something > > that should have been mentioned. > > > > Futher, debugfs_create_file() creates a full proxy for fops, protecting > > against removal races. DEFINE_DEBUGFS_ATTRIBUTE adds its own protection > > but just for ->read() and ->write(). I don't think we need both. > > > > > The coccinelle script clarifies some of this. See the commit log here: > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5103068eaca290f890a30aae70085fac44cecaf6 > > That said, it also mentions that the file should be converted to use > debugfs_create_file_unsafe now as well, and that wasn't done in this > patch. Jiapeng, was that intentional? If so, why? > For now, I've dropped this patch until the situation with debugfs_create_file_unsafe is clear. -- Jeff Layton <jlayton@kernel.org>
diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c index 66989c8..617327e 100644 --- a/fs/ceph/debugfs.c +++ b/fs/ceph/debugfs.c @@ -344,8 +344,8 @@ static int congestion_kb_get(void *data, u64 *val) return 0; } -DEFINE_SIMPLE_ATTRIBUTE(congestion_kb_fops, congestion_kb_get, - congestion_kb_set, "%llu\n"); +DEFINE_DEBUGFS_ATTRIBUTE(congestion_kb_fops, congestion_kb_get, + congestion_kb_set, "%llu\n"); void ceph_fs_debugfs_cleanup(struct ceph_fs_client *fsc)
Fix the following coccicheck warning: ./fs/ceph/debugfs.c:347:0-23: WARNING: congestion_kb_fops should be defined with DEFINE_DEBUGFS_ATTRIBUTE. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> --- fs/ceph/debugfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)