DriverDev-Devel Archive on lore.kernel.org
 help / color / Atom feed
From: Gao Xiang <gaoxiang25@huawei.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: devel@driverdev.osuosl.org,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	linux-erofs@lists.ozlabs.org, Chao Yu <yuchao0@huawei.com>,
	Theodore Ts'o <tytso@mit.edu>,
	"Darrick J . Wong" <darrick.wong@oracle.com>,
	Pavel Machek <pavel@denx.de>, Jan Kara <jack@suse.cz>,
	Amir Goldstein <amir73il@gmail.com>,
	Dave Chinner <david@fromorbit.com>,
	David Sterba <dsterba@suse.cz>,
	Li Guifu <bluce.liguifu@huawei.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Miao Xie <miaoxie@huawei.com>,
	Alexander Viro <viro@zeniv.linux.org.uk>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-fsdevel@vger.kernel.org, Jaegeuk Kim <jaegeuk@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Fang Wei <fangwei1@huawei.com>
Subject: Re: [PATCH v6 03/24] erofs: add super block operations
Date: Sat, 31 Aug 2019 01:15:11 +0800
Message-ID: <20190830171510.GC107220@architecture4> (raw)
In-Reply-To: <20190830163910.GB29603@infradead.org>

Hi Christoph,

On Fri, Aug 30, 2019 at 09:39:10AM -0700, Christoph Hellwig wrote:
> On Thu, Aug 29, 2019 at 06:50:48PM +0800, Gao Xiang wrote:
> > > Please use an erofs_ prefix for all your functions.
> > 
> > It is already a static function, I have no idea what is wrong here.
> 
> Which part of all wasn't clear?  Have you looked at the prefixes for
> most functions in the various other big filesystems?

I will add erofs prefix to free_inode as you said.

At least, all non-prefix functions in erofs are all static functions,
it won't pollute namespace... I will add "erofs_" to other meaningful
callbacks...And as you can see...

cifs/cifsfs.c
1303:cifs_init_inodecache(void)
1509:   rc = cifs_init_inodecache();

hpfs/super.c
254:static int init_inodecache(void)
771:    int err = init_inodecache();

minix/inode.c
84:static int __init init_inodecache(void)
665:    int err = init_inodecache();

isofs/inode.c
88:static int __init init_inodecache(void)
1580:   int err = init_inodecache();

bfs/inode.c
261:static int __init init_inodecache(void)
468:    int err = init_inodecache();

ext4/super.c
1144:static int __init init_inodecache(void)
6115:   err = init_inodecache();

reiserfs/super.c
666:static int __init init_inodecache(void)
2606:   ret = init_inodecache();

squashfs/super.c
406:static int __init init_inodecache(void)
430:    int err = init_inodecache();

udf/super.c
177:static int __init init_inodecache(void)
232:    err = init_inodecache();

qnx4/inode.c
358:static int init_inodecache(void)
399:    err = init_inodecache();

ufs/super.c
1463:static int __init init_inodecache(void)
1517:   int err = init_inodecache();

qnx6/inode.c
618:static int init_inodecache(void)
659:    err = init_inodecache();

f2fs/super.c
3540:static int __init init_inodecache(void)
3572:   err = init_inodecache();


> 
> > > > +	/* be careful RCU symlink path (see ext4_inode_info->i_data)! */
> > > > +	if (is_inode_fast_symlink(inode))
> > > > +		kfree(inode->i_link);
> > > 
> > > is_inode_fast_symlink only shows up in a later patch.  And really
> > > obsfucates the check here in the only caller as you can just do an
> > > unconditional kfree here - i_link will be NULL except for the case
> > > where you explicitly set it.
> > 
> > I cannot fully understand your point (sorry about my English),
> > I will reply you about this later.
> 
> With that I mean that you should:
> 
>  1) remove is_inode_fast_symlink and just opencode it in the few places
>     using it
>  2) remove the check in this place entirely as it is not needed
>  3) remove the comment quoted above as it is more confusing than not
>     having the comment

Got it, thanks!

> 
> > > Is there any good reasons to use buffer heads like this in new code
> > > vs directly using bios?
> > 
> > This page can save in bdev page cache, it contains not only the erofs
> > superblock so it can be fetched in page cache later.
> 
> If you want it in the page cache why not use read_mapping_page or similar?

It's reasonable, I will change as you suggested.
(The difference is whether it has some buffer_head to the sb page or not...)

> 
> > > > +/* set up default EROFS parameters */
> > > > +static void default_options(struct erofs_sb_info *sbi)
> > > > +{
> > > > +}
> > > 
> > > No need to add an empty function.
> > 
> > Later patch will fill this function.
> 
> Please only add the function in the patch actually adding the
> functionality.

That was my fault when spilting patches...considering
it's an >7KLOC filesystem (maybe spilting the whole xfs or
ext4 properly is more harder)... Anyway, that is my fault.

> 
> > > > +}
> > > 
> > > Why is this needed?  You can just free your sb privatte information in
> > > ->put_super and wire up kill_block_super as the ->kill_sb method
> > > directly.
> > 
> > See Al's comments,
> > https://lore.kernel.org/r/20190720224955.GD17978@ZenIV.linux.org.uk/
> 
> With that code it makes sense.  In this paticular patch it does not.
> So please add it only when actually needed.

Same as above...

Thanks,
Gao Xiang

_______________________________________________
devel mailing list
devel@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel

  reply index

Thread overview: 141+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-02 12:53 [PATCH v6 00/24] erofs: promote erofs from staging gaoxiang25
2019-08-02 12:53 ` [PATCH v6 01/24] erofs: add on-disk layout gaoxiang25
     [not found]   ` <20190829095954.GB20598@infradead.org>
2019-09-01  7:54     ` Gao Xiang
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
     [not found]     ` <20190829103252.GA64893@architecture4>
     [not found]       ` <67d6efbbc9ac6db23215660cb970b7ef29dc0c1d.camel@perches.com>
     [not found]         ` <20190830120714.GN2752@twin.jikos.cz>
2019-09-02  8:43           ` Pavel Machek
2019-09-02 14:07             ` David Sterba
2019-09-03 11:27               ` Pavel Machek
2019-08-02 12:53 ` [PATCH v6 02/24] erofs: add erofs in-memory stuffs gaoxiang25
2019-08-02 12:53 ` [PATCH v6 03/24] erofs: add super block operations gaoxiang25
     [not found]   ` <20190829101545.GC20598@infradead.org>
     [not found]     ` <20190829105048.GB64893@architecture4>
2019-08-30 16:39       ` Christoph Hellwig
2019-08-30 17:15         ` Gao Xiang [this message]
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
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 gaoxiang25
     [not found]   ` <20190829101721.GD20598@infradead.org>
     [not found]     ` <20190829114610.GF64893@architecture4>
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 gaoxiang25
     [not found]   ` <20190829102426.GE20598@infradead.org>
     [not found]     ` <20190829115922.GG64893@architecture4>
2019-08-30 16:42       ` Christoph Hellwig
2019-08-30 18:46         ` Gao Xiang
2019-09-01  9:34     ` Gao Xiang
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 gaoxiang25
     [not found]   ` <20190829102503.GF20598@infradead.org>
2019-09-01  9:39     ` Gao Xiang
2019-08-02 12:53 ` [PATCH v6 07/24] erofs: add directory operations gaoxiang25
2019-08-02 12:53 ` [PATCH v6 08/24] erofs: add namei functions gaoxiang25
2019-08-02 12:53 ` [PATCH v6 09/24] erofs: support tracepoint gaoxiang25
2019-08-02 12:53 ` [PATCH v6 10/24] erofs: update Kconfig and Makefile gaoxiang25
2019-08-02 12:53 ` [PATCH v6 11/24] erofs: introduce xattr & posixacl support gaoxiang25
2019-08-02 12:53 ` [PATCH v6 12/24] erofs: introduce tagged pointer gaoxiang25
2019-08-02 12:53 ` [PATCH v6 13/24] erofs: add compression indexes support gaoxiang25
2019-08-02 12:53 ` [PATCH v6 14/24] erofs: introduce superblock registration gaoxiang25
2019-08-02 12:53 ` [PATCH v6 15/24] erofs: introduce erofs shrinker gaoxiang25
2019-08-02 12:53 ` [PATCH v6 16/24] erofs: introduce workstation for decompression gaoxiang25
2019-08-02 12:53 ` [PATCH v6 17/24] erofs: introduce per-CPU buffers implementation gaoxiang25
2019-08-02 12:53 ` [PATCH v6 18/24] erofs: introduce pagevec for decompression subsystem gaoxiang25
2019-08-02 12:53 ` [PATCH v6 19/24] erofs: add erofs_allocpage() gaoxiang25
2019-08-02 12:53 ` [PATCH v6 20/24] erofs: introduce generic decompression backend gaoxiang25
2019-08-02 12:53 ` [PATCH v6 21/24] erofs: introduce LZ4 decompression inplace gaoxiang25
2019-08-02 12:53 ` [PATCH v6 22/24] erofs: introduce the decompression frontend gaoxiang25
2019-08-02 12:53 ` [PATCH v6 23/24] erofs: introduce cached decompression gaoxiang25
2019-08-02 12:53 ` [PATCH v6 24/24] erofs: add document gaoxiang25
2019-09-01  5:51 ` [PATCH 00/21] erofs: patchset addressing Christoph's comments Gao Xiang
2019-09-01  5:51   ` [PATCH 01/21] erofs: remove all the byte offset comments Gao Xiang
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
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
2019-09-02 12:06     ` Christoph Hellwig
2019-09-01  5:51   ` [PATCH 04/21] erofs: kill __packed for on-disk structures Gao Xiang
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
2019-09-02 12:07     ` Christoph Hellwig
2019-09-01  5:51   ` [PATCH 06/21] erofs: kill erofs_{init,exit}_inode_cache Gao Xiang
2019-09-02 12:09     ` Christoph Hellwig
2019-09-01  5:51   ` [PATCH 07/21] erofs: use erofs_inode naming Gao Xiang
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
2019-09-01  5:51   ` [PATCH 09/21] erofs: update erofs symlink stuffs Gao Xiang
2019-09-02 12:11     ` Christoph Hellwig
2019-09-01  5:51   ` [PATCH 10/21] erofs: kill is_inode_layout_compression() Gao Xiang
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
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
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
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
2019-09-02 12:21     ` Christoph Hellwig
2019-09-01  5:51   ` [PATCH 15/21] erofs: kill __submit_bio() Gao Xiang
2019-09-01  5:51   ` [PATCH 16/21] erofs: kill magic underscores Gao Xiang
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
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
2019-09-02 12:28     ` Christoph Hellwig
2019-09-01  5:51   ` [PATCH 19/21] erofs: kill all erofs specific fault injection Gao Xiang
2019-09-02 12:28     ` Christoph Hellwig
2019-09-01  5:51   ` [PATCH 20/21] erofs: kill use_vmap module parameter Gao Xiang
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
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
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
2019-09-05 11:30         ` Christoph Hellwig
2019-09-04  5:16     ` Christoph Hellwig
2019-09-04  6:08       ` Gao Xiang

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190830171510.GC107220@architecture4 \
    --to=gaoxiang25@huawei.com \
    --cc=akpm@linux-foundation.org \
    --cc=amir73il@gmail.com \
    --cc=bluce.liguifu@huawei.com \
    --cc=darrick.wong@oracle.com \
    --cc=david@fromorbit.com \
    --cc=devel@driverdev.osuosl.org \
    --cc=dsterba@suse.cz \
    --cc=fangwei1@huawei.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=hch@infradead.org \
    --cc=jack@suse.cz \
    --cc=jaegeuk@kernel.org \
    --cc=linux-erofs@lists.ozlabs.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=miaoxie@huawei.com \
    --cc=pavel@denx.de \
    --cc=sfr@canb.auug.org.au \
    --cc=torvalds@linux-foundation.org \
    --cc=tytso@mit.edu \
    --cc=viro@zeniv.linux.org.uk \
    --cc=yuchao0@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

DriverDev-Devel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/driverdev-devel/0 driverdev-devel/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 driverdev-devel driverdev-devel/ https://lore.kernel.org/driverdev-devel \
		driverdev-devel@linuxdriverproject.org devel@driverdev.osuosl.org driverdev-devel@archiver.kernel.org
	public-inbox-index driverdev-devel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.linuxdriverproject.driverdev-devel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox