On Mon, Sep 8, 2025 at 3:54 PM Jan Kara <jack@xxxxxxx> wrote: > > On Mon 08-09-25 20:41:21, Joseph Qi wrote: > > > > > > On 2025/9/8 18:23, Jan Kara wrote: > > > On Mon 08-09-25 09:51:36, Joseph Qi wrote: > > >> On 2025/9/5 00:22, Mateusz Guzik wrote: > > >>> On Thu, Sep 4, 2025 at 6:15 PM Mark Tinguely <mark.tinguely@xxxxxxxxxx> wrote: > > >>>> > > >>>> On 9/4/25 10:42 AM, Mateusz Guzik wrote: > > >>>>> This postpones the writeout to ocfs2_evict_inode(), which I'm told is > > >>>>> fine (tm). > > >>>>> > > >>>>> The intent is to retire the I_WILL_FREE flag. > > >>>>> > > >>>>> Signed-off-by: Mateusz Guzik <mjguzik@xxxxxxxxx> > > >>>>> --- > > >>>>> > > >>>>> ACHTUNG: only compile-time tested. Need an ocfs2 person to ack it. > > >>>>> > > >>>>> btw grep shows comments referencing ocfs2_drop_inode() which are already > > >>>>> stale on the stock kernel, I opted to not touch them. > > >>>>> > > >>>>> This ties into an effort to remove the I_WILL_FREE flag, unblocking > > >>>>> other work. If accepted would be probably best taken through vfs > > >>>>> branches with said work, see https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git/log/?h=vfs-6.18.inode.refcount.preliminaries__;!!ACWV5N9M2RV99hQ!OLwk8DVo7uvC-Pd6XVTiUCgP6MUDMKBMEyuV27h_yPGXOjaq078-kMdC9ILFoYQh-4WX93yb0nMfBDFFY_0$ > > >>>>> > > >>>>> fs/ocfs2/inode.c | 23 ++--------------------- > > >>>>> fs/ocfs2/inode.h | 1 - > > >>>>> fs/ocfs2/ocfs2_trace.h | 2 -- > > >>>>> fs/ocfs2/super.c | 2 +- > > >>>>> 4 files changed, 3 insertions(+), 25 deletions(-) > > >>>>> > > >>>>> diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c > > >>>>> index 6c4f78f473fb..5f4a2cbc505d 100644 > > >>>>> --- a/fs/ocfs2/inode.c > > >>>>> +++ b/fs/ocfs2/inode.c > > >>>>> @@ -1290,6 +1290,8 @@ static void ocfs2_clear_inode(struct inode *inode) > > >>>>> > > >>>>> void ocfs2_evict_inode(struct inode *inode) > > >>>>> { > > >>>>> + write_inode_now(inode, 1); > > >>>>> + > > >>>>> if (!inode->i_nlink || > > >>>>> (OCFS2_I(inode)->ip_flags & OCFS2_INODE_MAYBE_ORPHANED)) { > > >>>>> ocfs2_delete_inode(inode); > > >>>>> @@ -1299,27 +1301,6 @@ void ocfs2_evict_inode(struct inode *inode) > > >>>>> ocfs2_clear_inode(inode); > > >>>>> } > > >>>>> > > >>>>> -/* Called under inode_lock, with no more references on the > > >>>>> - * struct inode, so it's safe here to check the flags field > > >>>>> - * and to manipulate i_nlink without any other locks. */ > > >>>>> -int ocfs2_drop_inode(struct inode *inode) > > >>>>> -{ > > >>>>> - struct ocfs2_inode_info *oi = OCFS2_I(inode); > > >>>>> - > > >>>>> - trace_ocfs2_drop_inode((unsigned long long)oi->ip_blkno, > > >>>>> - inode->i_nlink, oi->ip_flags); > > >>>>> - > > >>>>> - assert_spin_locked(&inode->i_lock); > > >>>>> - inode->i_state |= I_WILL_FREE; > > >>>>> - spin_unlock(&inode->i_lock); > > >>>>> - write_inode_now(inode, 1); > > >>>>> - spin_lock(&inode->i_lock); > > >>>>> - WARN_ON(inode->i_state & I_NEW); > > >>>>> - inode->i_state &= ~I_WILL_FREE; > > >>>>> - > > >>>>> - return 1; > > >>>>> -} > > >>>>> - > > >>>>> /* > > >>>>> * This is called from our getattr. > > >>>>> */ > > >>>>> diff --git a/fs/ocfs2/inode.h b/fs/ocfs2/inode.h > > >>>>> index accf03d4765e..07bd838e7843 100644 > > >>>>> --- a/fs/ocfs2/inode.h > > >>>>> +++ b/fs/ocfs2/inode.h > > >>>>> @@ -116,7 +116,6 @@ static inline struct ocfs2_caching_info *INODE_CACHE(struct inode *inode) > > >>>>> } > > >>>>> > > >>>>> void ocfs2_evict_inode(struct inode *inode); > > >>>>> -int ocfs2_drop_inode(struct inode *inode); > > >>>>> > > >>>>> /* Flags for ocfs2_iget() */ > > >>>>> #define OCFS2_FI_FLAG_SYSFILE 0x1 > > >>>>> diff --git a/fs/ocfs2/ocfs2_trace.h b/fs/ocfs2/ocfs2_trace.h > > >>>>> index 54ed1495de9a..4b32fb5658ad 100644 > > >>>>> --- a/fs/ocfs2/ocfs2_trace.h > > >>>>> +++ b/fs/ocfs2/ocfs2_trace.h > > >>>>> @@ -1569,8 +1569,6 @@ DEFINE_OCFS2_ULL_ULL_UINT_EVENT(ocfs2_delete_inode); > > >>>>> > > >>>>> DEFINE_OCFS2_ULL_UINT_EVENT(ocfs2_clear_inode); > > >>>>> > > >>>>> -DEFINE_OCFS2_ULL_UINT_UINT_EVENT(ocfs2_drop_inode); > > >>>>> - > > >>>>> TRACE_EVENT(ocfs2_inode_revalidate, > > >>>>> TP_PROTO(void *inode, unsigned long long ino, > > >>>>> unsigned int flags), > > >>>>> diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c > > >>>>> index 53daa4482406..e4b0d25f4869 100644 > > >>>>> --- a/fs/ocfs2/super.c > > >>>>> +++ b/fs/ocfs2/super.c > > >>>>> @@ -129,7 +129,7 @@ static const struct super_operations ocfs2_sops = { > > >>>>> .statfs = ocfs2_statfs, > > >>>>> .alloc_inode = ocfs2_alloc_inode, > > >>>>> .free_inode = ocfs2_free_inode, > > >>>>> - .drop_inode = ocfs2_drop_inode, > > >>>>> + .drop_inode = generic_delete_inode, > > >>>>> .evict_inode = ocfs2_evict_inode, > > >>>>> .sync_fs = ocfs2_sync_fs, > > >>>>> .put_super = ocfs2_put_super, > > >>>> > > >>>> > > >>>> I agree, fileystems should not use I_FREEING/I_WILL_FREE. > > >>>> Doing the sync write_inode_now() should be fine in ocfs_evict_inode(). > > >>>> > > >>>> Question is ocfs_drop_inode. In commit 513e2dae9422: > > >>>> ocfs2: flush inode data to disk and free inode when i_count becomes zero > > >>>> the return of 1 drops immediate to fix a memory caching issue. > > >>>> Shouldn't .drop_inode() still return 1? > > >>> > > >>> generic_delete_inode is a stub doing just that. > > >>> > > >> In case of "drop = 0", it may return directly without calling evict(). > > >> This seems break the expectation of commit 513e2dae9422. > > > > > > generic_delete_inode() always returns 1 so evict() will be called. > > > ocfs2_drop_inode() always returns 1 as well after 513e2dae9422. So I'm not > > > sure which case of "drop = 0" do you see... > > > > > I don't see a real case, just in theory. > > As I described before, if we make sure write_inode_now() will be called > > in iput_final(), it would be fine. > > I'm sorry but I still don't quite understand what you are proposing. If > ->drop() returns 1, the filesystem wants to remove the inode from cache > (perhaps because it was deleted). Hence iput_final() doesn't bother with > writing out such inodes. This doesn't work well with ocfs2 wanting to > always drop inodes hence ocfs2 needs to write the inode itself in > ocfs2_evice_inode(). Perhaps you have some modification to iput_final() in > mind but I'm not sure how that would work so can you perhaps suggest a > patch if you think iput_final() should work differently? Thanks! > I think generic_delete_inode is a really bad name for what the routine is doing and it perhaps contributes to the confusion in the thread. Perhaps it could be renamed to inode_op_stub_always_drop or similar? I don't for specifics, apart from explicitly stating that the return value is to drop and bonus points for a prefix showing this is an inode thing. -- Mateusz Guzik <mjguzik gmail.com>
