[PATCH v2 0/6] Delete timespec64_trunc()

[PATCH v2 0/6] Delete timespec64_trunc()

[Deepa Dinamani]

This series aims at deleting timespec64_trunc().
There is a new api: timestamp_truncate() that is the
replacement api. The api additionally does a limits
check on the filesystem timestamps.

The suggestion to open code some of the truncate logic
came from Al Viro. And, this does make the code in some
filesystems easy to follow.

The series also does some update_time() cleanup as
suggested by Al Viro.

Deepa Dinamani (6):
  fs: fat: Eliminate timespec64_trunc() usage
  fs: cifs: Delete usage of timespec64_trunc
  fs: ceph: Delete timespec64_trunc() usage
  fs: ubifs: Eliminate timespec64_trunc() usage
  fs: Delete timespec64_trunc()
  fs: Do not overload update_time

 fs/ceph/mds_client.c |  4 +---
 fs/cifs/inode.c      | 13 +++++++------
 fs/fat/misc.c        | 10 +++++++++-
 fs/inode.c           | 33 +++------------------------------
 fs/ubifs/sb.c        | 11 ++++-------
 include/linux/fs.h   |  1 -
 6 files changed, 24 insertions(+), 48 deletions(-)

-- 
Changes since v1:
* Dropped the atime comparison (patch 2/7) taken through cifs tree.
* Refactored update_time according to review comments.
2.17.1

Cc: ceph-devel@vger.kernel.org
Cc: hirofumi@mail.parknet.co.jp
Cc: jlayton@kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: linux-mtd@lists.infradead.org
Cc: richard@nod.at
Cc: stfrench@microsoft.com

[PATCH v2 2/6] fs: cifs: Delete usage of timespec64_trunc

[Deepa Dinamani]

timestamp_truncate() is the replacement api for
timespec64_trunc. timestamp_truncate() additionally clamps
timestamps to make sure the timestamps lie within the
permitted range for the filesystem.

Truncate the timestamps in the struct cifs_attr at the
site of assignment to inode times. This
helps us use the right fs api timestamp_trucate() to
perform the truncation.

Also update the ktime_get_* api to match the one used in
current_time(). This allows for timestamps to be updated
the same way always.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: stfrench@microsoft.com
Cc: linux-cifs@vger.kernel.org
---
 fs/cifs/inode.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index ca76a9287456..026ed49e8aa4 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -113,6 +113,7 @@ cifs_revalidate_cache(struct inode *inode, struct cifs_fattr *fattr)
 	}
 
 	 /* revalidate if mtime or size have changed */
+	fattr->cf_mtime = timestamp_truncate(fattr->cf_mtime, inode);
 	if (timespec64_equal(&inode->i_mtime, &fattr->cf_mtime) &&
 	    cifs_i->server_eof == fattr->cf_eof) {
 		cifs_dbg(FYI, "%s: inode %llu is unchanged\n",
@@ -162,6 +163,9 @@ cifs_fattr_to_inode(struct inode *inode, struct cifs_fattr *fattr)
 	cifs_revalidate_cache(inode, fattr);
 
 	spin_lock(&inode->i_lock);
+	fattr->cf_mtime = timestamp_truncate(fattr->cf_mtime, inode);
+	fattr->cf_atime = timestamp_truncate(fattr->cf_atime, inode);
+	fattr->cf_ctime = timestamp_truncate(fattr->cf_ctime, inode);
 	/* we do not want atime to be less than mtime, it broke some apps */
 	if (timespec64_compare(&fattr->cf_atime, &fattr->cf_mtime) < 0)
 		inode->i_atime = fattr->cf_mtime;
@@ -329,8 +333,7 @@ cifs_create_dfs_fattr(struct cifs_fattr *fattr, struct super_block *sb)
 	fattr->cf_mode = S_IFDIR | S_IXUGO | S_IRWXU;
 	fattr->cf_uid = cifs_sb->mnt_uid;
 	fattr->cf_gid = cifs_sb->mnt_gid;
-	ktime_get_real_ts64(&fattr->cf_mtime);
-	fattr->cf_mtime = timespec64_trunc(fattr->cf_mtime, sb->s_time_gran);
+	ktime_get_coarse_real_ts64(&fattr->cf_mtime);
 	fattr->cf_atime = fattr->cf_ctime = fattr->cf_mtime;
 	fattr->cf_nlink = 2;
 	fattr->cf_flags = CIFS_FATTR_DFS_REFERRAL;
@@ -609,10 +612,8 @@ cifs_all_info_to_fattr(struct cifs_fattr *fattr, FILE_ALL_INFO *info,
 
 	if (info->LastAccessTime)
 		fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
-	else {
-		ktime_get_real_ts64(&fattr->cf_atime);
-		fattr->cf_atime = timespec64_trunc(fattr->cf_atime, sb->s_time_gran);
-	}
+	else
+		ktime_get_coarse_real_ts64(&fattr->cf_atime);
 
 	fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
 	fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
-- 
2.17.1

Re: [PATCH v2 0/6] Delete timespec64_trunc()

[Deepa Dinamani]

On Mon, Dec 2, 2019 at 9:20 PM Deepa Dinamani <deepa.kernel@gmail.com> wrote:
> This series aims at deleting timespec64_trunc().
> There is a new api: timestamp_truncate() that is the
> replacement api. The api additionally does a limits
> check on the filesystem timestamps.

Al/Andrew, can one of you help merge these patches?

Thanks,
-Deepa

Re: [PATCH v2 0/6] Delete timespec64_trunc()

[Al Viro]

On Thu, Dec 05, 2019 at 06:43:26PM -0800, Deepa Dinamani wrote:
> On Mon, Dec 2, 2019 at 9:20 PM Deepa Dinamani <deepa.kernel@gmail.com> wrote:
> > This series aims at deleting timespec64_trunc().
> > There is a new api: timestamp_truncate() that is the
> > replacement api. The api additionally does a limits
> > check on the filesystem timestamps.
> 
> Al/Andrew, can one of you help merge these patches?

Looks sane.  Could you check if #misc.timestamp looks sane to you?

One thing that leaves me scratching head is kernfs - surely we
are _not_ limited by any external layouts there, so why do we
need to bother with truncation?

Re: [PATCH v2 0/6] Delete timespec64_trunc()

[Deepa Dinamani]

On Fri, Dec 6, 2019 at 10:02 PM Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> On Thu, Dec 05, 2019 at 06:43:26PM -0800, Deepa Dinamani wrote:
> > On Mon, Dec 2, 2019 at 9:20 PM Deepa Dinamani <deepa.kernel@gmail.com> wrote:
> > > This series aims at deleting timespec64_trunc().
> > > There is a new api: timestamp_truncate() that is the
> > > replacement api. The api additionally does a limits
> > > check on the filesystem timestamps.
> >
> > Al/Andrew, can one of you help merge these patches?
>
> Looks sane.  Could you check if #misc.timestamp looks sane to you?

Yes, that looks sane to me.

> One thing that leaves me scratching head is kernfs - surely we
> are _not_ limited by any external layouts there, so why do we
> need to bother with truncation?

I think I was more pedantic then, and was explicitly truncating times
before assignment to inode timestamps. But, Arnd has since coached me
that we should not introduce things to safe guard against all
possibilities, but only what is needed currently. So this kernfs
truncate is redundant, given the limits and the granularity match vfs
timestamp representation limits.

-Deepa

Re: [PATCH v2 0/6] Delete timespec64_trunc()

[Al Viro]

On Sat, Dec 07, 2019 at 06:04:38PM -0800, Deepa Dinamani wrote:
> On Fri, Dec 6, 2019 at 10:02 PM Al Viro <viro@zeniv.linux.org.uk> wrote:
> >
> > On Thu, Dec 05, 2019 at 06:43:26PM -0800, Deepa Dinamani wrote:
> > > On Mon, Dec 2, 2019 at 9:20 PM Deepa Dinamani <deepa.kernel@gmail.com> wrote:
> > > > This series aims at deleting timespec64_trunc().
> > > > There is a new api: timestamp_truncate() that is the
> > > > replacement api. The api additionally does a limits
> > > > check on the filesystem timestamps.
> > >
> > > Al/Andrew, can one of you help merge these patches?
> >
> > Looks sane.  Could you check if #misc.timestamp looks sane to you?
> 
> Yes, that looks sane to me.
> 
> > One thing that leaves me scratching head is kernfs - surely we
> > are _not_ limited by any external layouts there, so why do we
> > need to bother with truncation?
> 
> I think I was more pedantic then, and was explicitly truncating times
> before assignment to inode timestamps. But, Arnd has since coached me
> that we should not introduce things to safe guard against all
> possibilities, but only what is needed currently. So this kernfs
> truncate is redundant, given the limits and the granularity match vfs
> timestamp representation limits.

OK...  I've tossed a followup removing the truncation from kernfs;
the whole series looks reasonably safe, but I don't think it's urgent
enough to even try getting it merged before -rc1.  So here's what
I'm going to do: immediately after -rc1 it gets renamed[*] to #imm.timestamp,
which will be in the never-modified mode, in #for-next from the very
begining and safe for other trees to pull.  Current shortlog:

Al Viro (1):
      kernfs: don't bother with timestamp truncation

Amir Goldstein (1):
      utimes: Clamp the timestamps in notify_change()

Deepa Dinamani (6):
      fs: fat: Eliminate timespec64_trunc() usage
      fs: cifs: Delete usage of timespec64_trunc
      fs: ceph: Delete timespec64_trunc() usage
      fs: ubifs: Eliminate timespec64_trunc() usage
      fs: Delete timespec64_trunc()
      fs: Do not overload update_time

Diffstat:
 fs/attr.c            | 23 +++++++++++------------
 fs/ceph/mds_client.c |  4 +---
 fs/cifs/inode.c      | 13 +++++++------
 fs/configfs/inode.c  |  9 +++------
 fs/f2fs/file.c       | 18 ++++++------------
 fs/fat/misc.c        | 10 +++++++++-
 fs/inode.c           | 33 +++------------------------------
 fs/kernfs/inode.c    |  6 +++---
 fs/ntfs/inode.c      | 18 ++++++------------
 fs/ubifs/file.c      | 18 ++++++------------
 fs/ubifs/sb.c        | 11 ++++-------
 fs/utimes.c          |  4 ++--
 include/linux/fs.h   |  1 -
 13 files changed, 61 insertions(+), 107 deletions(-)

[*] right now it's based on v5.4; I don't see anything that would
warrant rebasing it to -rc1 at the moment, but if anything of that
sort shows up tomorrow, s/renamed/rebased to -rc1 and renamed/.

Re: [PATCH v2 0/6] Delete timespec64_trunc()

[Al Viro]

On Sun, Dec 08, 2019 at 03:04:07AM +0000, Al Viro wrote:

> OK...  I've tossed a followup removing the truncation from kernfs;
> the whole series looks reasonably safe, but I don't think it's urgent
> enough to even try getting it merged before -rc1.  So here's what
> I'm going to do: immediately after -rc1 it gets renamed[*] to #imm.timestamp,
> which will be in the never-modified mode, in #for-next from the very
> begining and safe for other trees to pull.

Rebased to -rc1, pushed out as #imm.timestamp, included into #for-next.
Never-modified mode...