From: Eric Sandeen <sandeen@redhat.com>
To: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: torvalds@linux-foundation.org,
Miklos Szeredi <mszeredi@redhat.com>,
Ira Weiny <ira.weiny@intel.com>,
David Howells <dhowells@redhat.com>,
linux-fsdevel@vger.kernel.org, linux-man@vger.kernel.org,
linux-kernel@vger.kernel.org, xfs <linux-xfs@vger.kernel.org>,
linux-ext4@vger.kernel.org, Xiaoli Feng <xifeng@redhat.com>
Subject: Re: [PATCH 1/2] uapi: fix statx attribute value overlap for DAX & MOUNT_ROOT
Date: Tue, 1 Dec 2020 11:44:32 -0600 [thread overview]
Message-ID: <242fce05-90ed-2d2a-36f9-3c8432d57cbc@redhat.com> (raw)
In-Reply-To: <20201201173213.GH143045@magnolia>
On 12/1/20 11:32 AM, Darrick J. Wong wrote:
> On Tue, Dec 01, 2020 at 10:57:11AM -0600, Eric Sandeen wrote:
>> STATX_ATTR_MOUNT_ROOT and STATX_ATTR_DAX got merged with the same value,
>> so one of them needs fixing. Move STATX_ATTR_DAX.
>>
>> While we're in here, clarify the value-matching scheme for some of the
>> attributes, and explain why the value for DAX does not match.
>>
>> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
>> ---
>> include/uapi/linux/stat.h | 7 ++++---
>> 1 file changed, 4 insertions(+), 3 deletions(-)
>>
>> diff --git a/include/uapi/linux/stat.h b/include/uapi/linux/stat.h
>> index 82cc58fe9368..9ad19eb9bbbf 100644
>> --- a/include/uapi/linux/stat.h
>> +++ b/include/uapi/linux/stat.h
>> @@ -171,9 +171,10 @@ struct statx {
>> * be of use to ordinary userspace programs such as GUIs or ls rather than
>> * specialised tools.
>> *
>> - * Note that the flags marked [I] correspond to generic FS_IOC_FLAGS
>> + * Note that the flags marked [I] correspond to the FS_IOC_SETFLAGS flags
>> * semantically. Where possible, the numerical value is picked to correspond
>> - * also.
>> + * also. Note that the DAX attribute indicates that the inode is currently
>> + * DAX-enabled, not simply that the per-inode flag has been set.
>
> I don't really like using "DAX-enabled" to define "DAX attribute". How
> about cribbing from the statx manpage?
>
> "Note that the DAX attribute indicates that the file is in the CPU
> direct access state. It does not correspond to the per-inode flag that
> some filesystems support."
Sure. Consistency and specificity is good, I'll change that.
>> */
>> #define STATX_ATTR_COMPRESSED 0x00000004 /* [I] File is compressed by the fs */
>> #define STATX_ATTR_IMMUTABLE 0x00000010 /* [I] File is marked immutable */
>> @@ -183,7 +184,7 @@ struct statx {
>> #define STATX_ATTR_AUTOMOUNT 0x00001000 /* Dir: Automount trigger */
>> #define STATX_ATTR_MOUNT_ROOT 0x00002000 /* Root of a mount */
>> #define STATX_ATTR_VERITY 0x00100000 /* [I] Verity protected file */
>> -#define STATX_ATTR_DAX 0x00002000 /* [I] File is DAX */
>> +#define STATX_ATTR_DAX 0x00400000 /* File is currently DAX-enabled */
>
> Why not use the next bit in the series (0x200000)? Did someone already
> claim it in for-next?
Since it didn't match the FS_IOC_SETFLAGS flag, I was trying to pick one that
seemed unlikely to ever gain a corresponding statx flag, and since 0x00400000 is
"reserved for ext4" it seemed like a decent choice.
But 0x200000 corresponds to FS_EA_INODE_FL/EXT4_EA_INODE_FL which is ext4-specific
as well, so sure, I'll change to that.
Thanks,
-Eric
> --D
>
>>
>>
>> #endif /* _UAPI_LINUX_STAT_H */
>> --
>> 2.17.0
>>
>
next prev parent reply other threads:[~2020-12-01 17:46 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-01 16:54 [PATCH 0/2] statx: Fix DAX attribute collision and handling Eric Sandeen
2020-12-01 16:57 ` [PATCH 1/2] uapi: fix statx attribute value overlap for DAX & MOUNT_ROOT Eric Sandeen
2020-12-01 17:32 ` Darrick J. Wong
2020-12-01 17:44 ` Eric Sandeen [this message]
2020-12-01 18:31 ` Andreas Dilger
2020-12-01 18:36 ` Eric Sandeen
2020-12-02 2:16 ` Ira Weiny
2020-12-02 20:42 ` Linus Torvalds
2020-12-03 2:45 ` Ira Weiny
2020-12-03 18:04 ` Linus Torvalds
2020-12-01 16:59 ` [PATCH 2/2] statx: move STATX_ATTR_DAX attribute handling to filesystems Eric Sandeen
2020-12-01 17:39 ` Darrick J. Wong
2020-12-01 17:53 ` Eric Sandeen
2020-12-01 20:52 ` Dave Chinner
2020-12-01 22:03 ` Eric Sandeen
2020-12-01 22:12 ` Linus Torvalds
2020-12-01 22:26 ` Eric Sandeen
2020-12-02 2:29 ` Ira Weiny
2020-12-02 8:03 ` Christoph Hellwig
2020-12-01 20:04 ` Linus Torvalds
2020-12-01 20:50 ` Eric Sandeen
2020-12-01 21:04 ` David Howells
2020-12-01 22:09 ` Linus Torvalds
2020-12-02 0:11 ` Eric Sandeen
2020-12-01 17:18 ` [PATCH 1/2] uapi: fix statx attribute value overlap for DAX & MOUNT_ROOT David Howells
2020-12-01 17:20 ` [PATCH 2/2] statx: move STATX_ATTR_DAX attribute handling to filesystems David Howells
2020-12-01 17:28 ` David Howells
Reply instructions:
You may reply publicly 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=242fce05-90ed-2d2a-36f9-3c8432d57cbc@redhat.com \
--to=sandeen@redhat.com \
--cc=darrick.wong@oracle.com \
--cc=dhowells@redhat.com \
--cc=ira.weiny@intel.com \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-man@vger.kernel.org \
--cc=linux-xfs@vger.kernel.org \
--cc=mszeredi@redhat.com \
--cc=torvalds@linux-foundation.org \
--cc=xifeng@redhat.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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).