From: Gao Xiang via Linux-erofs <linux-erofs@lists.ozlabs.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: devel@driverdev.osuosl.org,
Stephen Rothwell <sfr@canb.auug.org.au>,
linux-erofs@lists.ozlabs.org, Jan Kara <jack@suse.cz>,
"Darrick J . Wong" <darrick.wong@oracle.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Amir Goldstein <amir73il@gmail.com>,
Dave Chinner <david@fromorbit.com>,
LKML <linux-kernel@vger.kernel.org>,
Theodore Ts'o <tytso@mit.edu>, Pavel Machek <pavel@denx.de>,
David Sterba <dsterba@suse.cz>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Jaegeuk Kim <jaegeuk@kernel.org>,
linux-fsdevel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Miao Xie <miaoxie@huawei.com>
Subject: Re: [PATCH v6 05/24] erofs: add inode operations
Date: Sun, 1 Sep 2019 17:34:00 +0800 [thread overview]
Message-ID: <20190901093326.GA6267@hsiangkao-HP-ZHAN-66-Pro-G1> (raw)
In-Reply-To: <20190829102426.GE20598@infradead.org>
Hi Christoph,
Here are redo-ed comments of your suggestions...
On Thu, Aug 29, 2019 at 03:24:26AM -0700, Christoph Hellwig wrote:
> On Fri, Aug 02, 2019 at 08:53:28PM +0800, Gao Xiang wrote:
> > This adds core functions to get, read an inode.
> > It adds statx support as well.
> >
> > Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
> > ---
> > fs/erofs/inode.c | 291 +++++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 291 insertions(+)
> > create mode 100644 fs/erofs/inode.c
> >
> > diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
> > new file mode 100644
> > index 000000000000..b6ea997bc4ae
> > --- /dev/null
> > +++ b/fs/erofs/inode.c
> > @@ -0,0 +1,291 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * linux/fs/erofs/inode.c
> > + *
> > + * Copyright (C) 2017-2018 HUAWEI, Inc.
> > + * http://www.huawei.com/
> > + * Created by Gao Xiang <gaoxiang25@huawei.com>
> > + */
> > +#include "internal.h"
> > +
> > +#include <trace/events/erofs.h>
> > +
> > +/* no locking */
> > +static int read_inode(struct inode *inode, void *data)
> > +{
> > + struct erofs_vnode *vi = EROFS_V(inode);
> > + struct erofs_inode_v1 *v1 = data;
> > + const unsigned int advise = le16_to_cpu(v1->i_advise);
> > + erofs_blk_t nblks = 0;
> > +
> > + vi->datamode = __inode_data_mapping(advise);
>
> What is the deal with these magic underscores here and various
> other similar helpers?
Fixed in
https://lore.kernel.org/linux-fsdevel/20190901055130.30572-17-hsiangkao@aol.com/
underscores means 'internal' in my thought, it seems somewhat
some common practice of Linux kernel, or some recent discussions
about it?... I didn't notice these discussions...
>
> > + /* fast symlink (following ext4) */
>
> This actually originates in FFS. But it is so common that the comment
> seems a little pointless.
Fixed in
https://lore.kernel.org/linux-fsdevel/20190901055130.30572-9-hsiangkao@aol.com/
>
> > + if (S_ISLNK(inode->i_mode) && inode->i_size < PAGE_SIZE) {
> > + char *lnk = erofs_kmalloc(sbi, inode->i_size + 1, GFP_KERNEL);
>
> Please just use plain kmalloc everywhere and let the normal kernel
> error injection code take care of injeting any errors.
Fixed in
https://lore.kernel.org/linux-fsdevel/20190901055130.30572-20-hsiangkao@aol.com/
>
> > + /* inline symlink data shouldn't across page boundary as well */
>
> ... should not cross ..
Fixed in
https://lore.kernel.org/linux-fsdevel/20190901055130.30572-9-hsiangkao@aol.com/
>
> > + if (unlikely(m_pofs + inode->i_size > PAGE_SIZE)) {
> > + DBG_BUGON(1);
> > + kfree(lnk);
> > + return -EIO;
> > + }
> > +
> > + /* get in-page inline data */
>
> s/get/copy/, but the comment seems rather pointless.
Fixed in
https://lore.kernel.org/linux-fsdevel/20190901055130.30572-9-hsiangkao@aol.com/
>
> > + memcpy(lnk, data + m_pofs, inode->i_size);
> > + lnk[inode->i_size] = '\0';
> > +
> > + inode->i_link = lnk;
> > + set_inode_fast_symlink(inode);
>
> Please just set the ops directly instead of obsfucating that in a single
> caller, single line inline function. And please set it instead of the
> normal symlink iops in the same place where you also set those.:w
Fixed in
https://lore.kernel.org/linux-fsdevel/20190901055130.30572-10-hsiangkao@aol.com/
>
> > + err = read_inode(inode, data + ofs);
> > + if (!err) {
>
> if (err)
> goto out_unlock;
>
> .. and save one level of indentation.
Fixed in
https://lore.kernel.org/linux-fsdevel/20190901055130.30572-22-hsiangkao@aol.com/
>
> > + if (is_inode_layout_compression(inode)) {
>
> The name of this helper is a little odd. But I think just
> opencoding it seems generally cleaner anyway.
Fixed in
https://lore.kernel.org/linux-fsdevel/20190901055130.30572-11-hsiangkao@aol.com/
>
>
> > + err = -ENOTSUPP;
> > + goto out_unlock;
> > + }
> > +
> > + inode->i_mapping->a_ops = &erofs_raw_access_aops;
> > +
> > + /* fill last page if inline data is available */
> > + err = fill_inline_data(inode, data, ofs);
>
> Well, I think you should move the is_inode_flat_inline and
> (S_ISLNK(inode->i_mode) && inode->i_size < PAGE_SIZE) checks from that
> helper here, as otherwise you make everyone wonder why you'd always
> fill out the inline data.
fill_inline_data is killed, and the similar function turns into
erofs_fill_symlink which is called at erofs_fill_inode():
case S_IFLNK:
- /* by default, page_get_link is used for symlink */
- inode->i_op = &erofs_symlink_iops;
+ err = erofs_fill_symlink(inode, data, ofs);
+ if (err)
+ goto out_unlock;
inode_nohighmem(inode);
break;
>
> > +static inline struct inode *erofs_iget_locked(struct super_block *sb,
> > + erofs_nid_t nid)
> > +{
> > + const unsigned long hashval = erofs_inode_hash(nid);
> > +
> > +#if BITS_PER_LONG >= 64
> > + /* it is safe to use iget_locked for >= 64-bit platform */
> > + return iget_locked(sb, hashval);
> > +#else
> > + return iget5_locked(sb, hashval, erofs_ilookup_test_actor,
> > + erofs_iget_set_actor, &nid);
> > +#endif
>
> Just use the slightly more complicated 32-bit version everywhere so that
> you have a single actually tested code path. And then remove this
> helper.
As I said before, 64-bit platforms is common currently,
I think iget_locked is enough.
https://lore.kernel.org/r/20190830184606.GA175612@architecture4/
Thanks,
Gao Xiang
next prev parent reply other threads:[~2019-09-01 9:34 UTC|newest]
Thread overview: 159+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-02 12:53 [PATCH v6 00/24] erofs: promote erofs from staging Gao Xiang
2019-08-02 12:53 ` [PATCH v6 01/24] erofs: add on-disk layout Gao Xiang
2019-08-29 9:59 ` Christoph Hellwig
2019-08-29 10:32 ` Gao Xiang
2019-08-29 10:36 ` Christoph Hellwig
2019-08-29 10:58 ` Gao Xiang
2019-08-29 15:58 ` Joe Perches
2019-08-29 17:26 ` Gao Xiang
2019-08-30 12:07 ` David Sterba
2019-08-30 12:18 ` Gao Xiang via Linux-erofs
2019-09-02 8:43 ` Pavel Machek
2019-09-02 14:07 ` David Sterba
2019-09-03 11:27 ` Pavel Machek
2019-08-29 15:41 ` Gao Xiang
2019-09-01 7:54 ` Gao Xiang via Linux-erofs
2019-09-02 12:45 ` Christoph Hellwig
2019-09-02 13:02 ` Gao Xiang
2019-09-02 8:40 ` Pavel Machek
2019-09-02 10:35 ` Gao Xiang
2019-08-02 12:53 ` [PATCH v6 02/24] erofs: add erofs in-memory stuffs Gao Xiang
2019-08-02 12:53 ` [PATCH v6 03/24] erofs: add super block operations Gao Xiang
2019-08-29 10:15 ` Christoph Hellwig
2019-08-29 10:50 ` Gao Xiang
2019-08-30 16:39 ` Christoph Hellwig
2019-08-30 17:15 ` Gao Xiang
2019-08-31 0:54 ` Gao Xiang
2019-08-31 6:34 ` Amir Goldstein
2019-08-31 6:48 ` Gao Xiang
2019-09-01 8:54 ` Gao Xiang via Linux-erofs
2019-09-02 12:51 ` Christoph Hellwig
2019-09-02 14:43 ` Gao Xiang
2019-09-02 15:19 ` Christoph Hellwig
2019-09-02 15:24 ` Gao Xiang
2019-08-02 12:53 ` [PATCH v6 04/24] erofs: add raw address_space operations Gao Xiang
2019-08-29 10:17 ` Christoph Hellwig
2019-08-29 11:46 ` Gao Xiang
2019-08-30 16:40 ` Christoph Hellwig
2019-08-30 17:23 ` Gao Xiang
2019-08-02 12:53 ` [PATCH v6 05/24] erofs: add inode operations Gao Xiang
2019-08-29 10:24 ` Christoph Hellwig
2019-08-29 11:59 ` Gao Xiang
2019-08-30 16:42 ` Christoph Hellwig
2019-08-30 18:46 ` Gao Xiang
2019-09-01 9:34 ` Gao Xiang via Linux-erofs [this message]
2019-09-02 12:53 ` Christoph Hellwig
2019-09-02 13:43 ` David Sterba
2019-09-02 13:55 ` Gao Xiang
2019-08-02 12:53 ` [PATCH v6 06/24] erofs: support special inode Gao Xiang
2019-08-29 10:25 ` Christoph Hellwig
2019-09-01 9:39 ` Gao Xiang via Linux-erofs
2019-08-02 12:53 ` [PATCH v6 07/24] erofs: add directory operations Gao Xiang
2019-08-02 12:53 ` [PATCH v6 08/24] erofs: add namei functions Gao Xiang
2019-08-29 10:28 ` Christoph Hellwig
2019-08-29 11:28 ` Gao Xiang
2019-08-02 12:53 ` [PATCH v6 09/24] erofs: support tracepoint Gao Xiang
2019-08-02 12:53 ` [PATCH v6 10/24] erofs: update Kconfig and Makefile Gao Xiang
2019-08-02 12:53 ` [PATCH v6 11/24] erofs: introduce xattr & posixacl support Gao Xiang
2019-08-02 12:53 ` [PATCH v6 12/24] erofs: introduce tagged pointer Gao Xiang
2019-08-02 12:53 ` [PATCH v6 13/24] erofs: add compression indexes support Gao Xiang
2019-08-02 12:53 ` [PATCH v6 14/24] erofs: introduce superblock registration Gao Xiang
2019-08-02 12:53 ` [PATCH v6 15/24] erofs: introduce erofs shrinker Gao Xiang
2019-08-02 12:53 ` [PATCH v6 16/24] erofs: introduce workstation for decompression Gao Xiang
2019-08-02 12:53 ` [PATCH v6 17/24] erofs: introduce per-CPU buffers implementation Gao Xiang
2019-08-02 12:53 ` [PATCH v6 18/24] erofs: introduce pagevec for decompression subsystem Gao Xiang
2019-08-02 12:53 ` [PATCH v6 19/24] erofs: add erofs_allocpage() Gao Xiang
2019-08-02 12:53 ` [PATCH v6 20/24] erofs: introduce generic decompression backend Gao Xiang
2019-08-02 12:53 ` [PATCH v6 21/24] erofs: introduce LZ4 decompression inplace Gao Xiang
2019-08-02 12:53 ` [PATCH v6 22/24] erofs: introduce the decompression frontend Gao Xiang
2019-08-02 12:53 ` [PATCH v6 23/24] erofs: introduce cached decompression Gao Xiang
2019-08-02 12:53 ` [PATCH v6 24/24] erofs: add document Gao Xiang
2019-09-01 5:51 ` [PATCH 00/21] erofs: patchset addressing Christoph's comments Gao Xiang via Linux-erofs
2019-09-01 5:51 ` [PATCH 01/21] erofs: remove all the byte offset comments Gao Xiang via Linux-erofs
2019-09-02 12:05 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 02/21] erofs: on-disk format should have explicitly assigned numbers Gao Xiang via Linux-erofs
2019-09-02 12:05 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 03/21] erofs: some macros are much more readable as a function Gao Xiang via Linux-erofs
2019-09-02 12:06 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 04/21] erofs: kill __packed for on-disk structures Gao Xiang via Linux-erofs
2019-09-02 12:06 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 05/21] erofs: update erofs_inode_is_data_compressed helper Gao Xiang via Linux-erofs
2019-09-02 12:07 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 06/21] erofs: kill erofs_{init,exit}_inode_cache Gao Xiang via Linux-erofs
2019-09-02 12:09 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 07/21] erofs: use erofs_inode naming Gao Xiang via Linux-erofs
2019-09-02 12:10 ` Christoph Hellwig
2019-09-02 12:13 ` Gao Xiang
2019-09-02 12:47 ` Christoph Hellwig
2019-09-02 13:33 ` Gao Xiang
2019-09-01 5:51 ` [PATCH 08/21] erofs: update comments in inode.c Gao Xiang via Linux-erofs
2019-09-01 5:51 ` [PATCH 09/21] erofs: update erofs symlink stuffs Gao Xiang via Linux-erofs
2019-09-02 12:11 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 10/21] erofs: kill is_inode_layout_compression() Gao Xiang via Linux-erofs
2019-09-02 12:11 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 11/21] erofs: use dsb instead of layout for ondisk super_block Gao Xiang via Linux-erofs
2019-09-02 12:12 ` Christoph Hellwig
2019-09-02 12:15 ` Gao Xiang
2019-09-01 5:51 ` [PATCH 12/21] erofs: kill verbose debug info in erofs_fill_super Gao Xiang via Linux-erofs
2019-09-02 12:14 ` Christoph Hellwig
2019-09-02 12:18 ` Gao Xiang
2019-09-01 5:51 ` [PATCH 13/21] erofs: simplify erofs_grab_bio() since bio_alloc() never fail Gao Xiang via Linux-erofs
2019-09-02 12:20 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 14/21] erofs: kill prio and nofail of erofs_get_meta_page() Gao Xiang via Linux-erofs
2019-09-02 12:21 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 15/21] erofs: kill __submit_bio() Gao Xiang via Linux-erofs
2019-09-01 5:51 ` [PATCH 16/21] erofs: kill magic underscores Gao Xiang via Linux-erofs
2019-09-02 12:26 ` Christoph Hellwig
2019-09-02 12:39 ` Gao Xiang
2019-09-02 12:54 ` Christoph Hellwig
2019-09-02 13:38 ` Gao Xiang
2019-09-01 5:51 ` [PATCH 17/21] erofs: use a switch statement when dealing with the file modes Gao Xiang via Linux-erofs
2019-09-02 12:27 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 18/21] erofs: add "erofs_" prefix for common and short functions Gao Xiang via Linux-erofs
2019-09-02 12:28 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 19/21] erofs: kill all erofs specific fault injection Gao Xiang via Linux-erofs
2019-09-02 12:28 ` Christoph Hellwig
2019-09-01 5:51 ` [PATCH 20/21] erofs: kill use_vmap module parameter Gao Xiang via Linux-erofs
2019-09-02 12:31 ` Christoph Hellwig
2019-09-02 12:43 ` Gao Xiang
2019-09-01 5:51 ` [PATCH 21/21] erofs: save one level of indentation Gao Xiang via Linux-erofs
2019-09-02 12:31 ` Christoph Hellwig
2019-09-02 12:46 ` [PATCH 00/21] erofs: patchset addressing Christoph's comments Christoph Hellwig
2019-09-02 14:24 ` Gao Xiang
2019-09-02 15:23 ` Christoph Hellwig
2019-09-02 15:50 ` Gao Xiang
2019-09-03 6:58 ` Christoph Hellwig
2019-09-03 8:17 ` Gao Xiang
2019-09-03 15:37 ` Christoph Hellwig
2019-09-03 15:43 ` Gao Xiang via Linux-erofs
2019-09-04 2:08 ` [PATCH v2 00/25] " Gao Xiang
2019-09-04 2:08 ` [PATCH v2 01/25] erofs: remove all the byte offset comments Gao Xiang
2019-09-04 2:08 ` [PATCH v2 02/25] erofs: on-disk format should have explicitly assigned numbers Gao Xiang
2019-09-04 2:08 ` [PATCH v2 03/25] erofs: some macros are much more readable as a function Gao Xiang
2019-09-04 2:08 ` [PATCH v2 04/25] erofs: kill __packed for on-disk structures Gao Xiang
2019-09-04 2:08 ` [PATCH v2 05/25] erofs: update erofs_inode_is_data_compressed helper Gao Xiang
2019-09-04 2:08 ` [PATCH v2 06/25] erofs: use feature_incompat rather than requirements Gao Xiang
2019-09-04 2:08 ` [PATCH v2 07/25] erofs: better naming for erofs inode related stuffs Gao Xiang
2019-09-04 2:08 ` [PATCH v2 08/25] erofs: kill erofs_{init,exit}_inode_cache Gao Xiang
2019-09-04 2:08 ` [PATCH v2 09/25] erofs: use erofs_inode naming Gao Xiang
2019-09-04 2:08 ` [PATCH v2 10/25] erofs: update erofs_fs.h comments Gao Xiang
2019-09-04 2:08 ` [PATCH v2 11/25] erofs: update comments in inode.c Gao Xiang
2019-09-04 2:08 ` [PATCH v2 12/25] erofs: better erofs symlink stuffs Gao Xiang
2019-09-04 2:09 ` [PATCH v2 13/25] erofs: use dsb instead of layout for ondisk super_block Gao Xiang
2019-09-04 2:09 ` [PATCH v2 14/25] erofs: kill verbose debug info in erofs_fill_super Gao Xiang
2019-09-04 2:09 ` [PATCH v2 15/25] erofs: localize erofs_grab_bio() Gao Xiang
2019-09-04 2:09 ` [PATCH v2 16/25] erofs: kill prio and nofail of erofs_get_meta_page() Gao Xiang
2019-09-04 2:09 ` [PATCH v2 17/25] erofs: kill __submit_bio() Gao Xiang
2019-09-04 2:09 ` [PATCH v2 18/25] erofs: add "erofs_" prefix for common and short functions Gao Xiang
2019-09-04 2:09 ` [PATCH v2 19/25] erofs: kill all erofs specific fault injection Gao Xiang
2019-09-04 2:09 ` [PATCH v2 20/25] erofs: kill use_vmap module parameter Gao Xiang
2019-09-04 2:09 ` [PATCH v2 21/25] erofs: save one level of indentation Gao Xiang
2019-09-04 2:09 ` [PATCH v2 22/25] erofs: rename errln/infoln/debugln to erofs_{err, info, dbg} Gao Xiang
2019-09-04 2:09 ` [PATCH v2 23/25] erofs: use read_mapping_page instead of sb_bread Gao Xiang
2019-09-04 2:09 ` [PATCH v2 24/25] erofs: always use iget5_locked Gao Xiang
2019-09-04 2:09 ` [PATCH v2 25/25] erofs: use read_cache_page_gfp for erofs_get_meta_page Gao Xiang
2019-09-04 3:27 ` [PATCH v2 00/25] erofs: patchset addressing Christoph's comments Chao Yu
2019-09-05 1:03 ` Gao Xiang via Linux-erofs
2019-09-05 11:30 ` Christoph Hellwig
2019-09-04 5:16 ` Christoph Hellwig
2019-09-04 6:08 ` Gao Xiang via Linux-erofs
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