[00/20] vfs: Add support for timestamp limits

The series is an update and a more complete version of the
previously posted series at
https://lore.kernel.org/linux-fsdevel/20180122020426.2988-1-deepa.kernel@gmail.com/

Thanks to Arnd Bergmann for doing a few preliminary reviews.
They helped me fix a few issues I had overlooked.

The limits (sometimes granularity also) for the filesystems updated here are according to the
following table:

File system   Time type                      Start year Expiration year Granularity
cramfs        fixed                          0          0
romfs         fixed                          0          0
pstore        ascii seconds (27 digit ascii) S64_MIN    S64_MAX         NSEC_PER_USEC
coda          INT64                          S64_MIN    S64_MAX         1
omfs          64-bit milliseconds            0          U64_MAX/ 1000   NSEC_PER_MSEC
befs          unsigned 48-bit seconds        0          0xffffffffffff  alloc_super
bfs           unsigned 32-bit seconds        0          U32_MAX         alloc_super
efs           unsigned 32-bit seconds        0          U32_MAX         alloc_super
ext2          signed 32-bit seconds          S32_MIN    S32_MAX         alloc_super
ext3          signed 32-bit seconds          S32_MIN    S32_MAX         alloc_super
ext4 (old)    signed 32-bit seconds          S32_MIN    S32_MAX         alloc_super
ext4 (extra)  34-bit seconds, 30-bit ns      S32_MIN    0x37fffffff	1
freevxfs      u32 secs/usecs                 0          U32_MAX         alloc_super
jffs2         unsigned 32-bit seconds        0          U32_MAX         alloc_super
jfs           unsigned 32-bit seconds/ns     0          U32_MAX         1
minix         unsigned 32-bit seconds        0          U32_MAX         alloc_super
orangefs      u64 seconds                    0          U64_MAX         alloc_super
qnx4          unsigned 32-bit seconds        0          U32_MAX         alloc_super
qnx6          unsigned 32-bit seconds        0          U32_MAX         alloc_super
reiserfs      unsigned 32-bit seconds        0          U32_MAX         alloc_super
squashfs      unsigned 32-bit seconds        0          U32_MAX         alloc_super
ufs1          signed 32-bit seconds          S32_MIN    S32_MAX         NSEC_PER_SEC
ufs2          signed 64-bit seconds/u32 ns   S64_MIN    S64_MAX         1
xfs           signed 32-bit seconds/ns       S32_MIN    S32_MAX         1
ceph          unsigned 32-bit second/ns      0          U32_MAX         1000
sysv          unsigned 32-bit seconds        0          U32_MAX         alloc_super
affs          u32 day, min, ticks            1978       u32_max days    NSEC_PER_SEC
nfsv2         unsigned 32-bit seconds/ns     0          U32_MAX         1
nfsv3         unsigned 32-bit seconds/ns     0          U32_MAX         1000
nfsv4         u64 seconds/u32 ns             S64_MIN    S64_MAX         1000
isofs         u8 year since 1900 (fixable)   1900       2155            alloc_super
hpfs          unsigned 32-bit seconds        1970       2106            alloc_super
fat           7-bit years, 2s resolution     1980       2107
cifs (smb)    7-bit years                    1980       2107
cifs (modern) 64-bit 100ns since 1601        1601       30828
adfs          40-bit cs since 1900           1900       2248
9p (9P2000)   unsigned 32-bit seconds        1970       2106
9p (9P2000.L) signed 64-bit seconds, ns      1970       S64_MAX

Granularity column filled in by the alloc_super() in the above table indicates that
the granularity is NSEC_PER_SEC.
Note that anything not mentioned above still has the default limits
S64_MIN..S64_MAX.

The patches in the series are as structured below:
1. Add vfs support to maintain the limits per filesystem.
2. Add a new timestamp_truncate() api for clamping timestamps
   according to the filesystem limits.
3. Add a warning for mount syscall to indicate the impending
   expiry of timestamps.
4. Modify utimes to clamp the timestamps.
5. Fill in limits for filesystems.

An updated version of the test for checking file system timestamp limits has been posted
at https://www.spinics.net/lists/fstests/msg12262.html

Changes from previous version:
* No change in mount behavior because of expiry of timestamps.
* Included limits for more filesystems.

Deepa Dinamani (20):
  vfs: Add file timestamp range support
  vfs: Add timestamp_truncate() api
  timestamp_truncate: Replace users of timespec64_trunc
  mount: Add mount warning for impending timestamp expiry
  utimes: Clamp the timestamps before update
  fs: Fill in max and min timestamps in superblock
  9p: Fill min and max timestamps in sb
  adfs: Fill in max and min timestamps in sb
  ext4: Initialize timestamps limits
  fs: nfs: Initialize filesystem timestamp ranges
  fs: cifs: Initialize filesystem timestamp ranges
  fs: fat: Initialize filesystem timestamp ranges
  fs: affs: Initialize filesystem timestamp ranges
  fs: sysv: Initialize filesystem timestamp ranges
  fs: ceph: Initialize filesystem timestamp ranges
  fs: orangefs: Initialize filesystem timestamp ranges
  fs: hpfs: Initialize filesystem timestamp ranges
  fs: omfs: Initialize filesystem timestamp ranges
  pstore: fs superblock limits
  isofs: Initialize filesystem timestamp ranges

 fs/9p/vfs_super.c        |  6 +++++-
 fs/adfs/adfs.h           | 13 +++++++++++++
 fs/adfs/inode.c          |  8 ++------
 fs/adfs/super.c          |  2 ++
 fs/affs/amigaffs.c       |  2 +-
 fs/affs/amigaffs.h       |  3 +++
 fs/affs/inode.c          |  4 ++--
 fs/affs/super.c          |  4 ++++
 fs/attr.c                | 21 ++++++++++++---------
 fs/befs/linuxvfs.c       |  2 ++
 fs/bfs/inode.c           |  2 ++
 fs/ceph/super.c          |  2 ++
 fs/cifs/cifsfs.c         | 22 ++++++++++++++++++++++
 fs/cifs/netmisc.c        | 14 +++++++-------
 fs/coda/inode.c          |  3 +++
 fs/configfs/inode.c      | 12 ++++++------
 fs/cramfs/inode.c        |  2 ++
 fs/efs/super.c           |  2 ++
 fs/ext2/super.c          |  2 ++
 fs/ext4/ext4.h           |  4 ++++
 fs/ext4/super.c          | 17 +++++++++++++++--
 fs/f2fs/file.c           | 21 ++++++++++++---------
 fs/fat/inode.c           | 12 ++++++++++++
 fs/fat/misc.c            |  5 +++--
 fs/freevxfs/vxfs_super.c |  2 ++
 fs/hpfs/hpfs_fn.h        |  6 ++----
 fs/hpfs/super.c          |  2 ++
 fs/inode.c               | 33 ++++++++++++++++++++++++++++++++-
 fs/isofs/inode.c         |  7 +++++++
 fs/jffs2/fs.c            |  3 +++
 fs/jfs/super.c           |  2 ++
 fs/kernfs/inode.c        |  6 +++---
 fs/minix/inode.c         |  2 ++
 fs/namespace.c           | 11 +++++++++++
 fs/nfs/super.c           | 20 +++++++++++++++++++-
 fs/ntfs/inode.c          | 21 ++++++++++++---------
 fs/omfs/inode.c          |  4 ++++
 fs/orangefs/super.c      |  2 ++
 fs/pstore/inode.c        |  4 +++-
 fs/qnx4/inode.c          |  2 ++
 fs/qnx6/inode.c          |  2 ++
 fs/reiserfs/super.c      |  3 +++
 fs/romfs/super.c         |  2 ++
 fs/squashfs/super.c      |  2 ++
 fs/super.c               |  2 ++
 fs/sysv/super.c          |  5 ++++-
 fs/ubifs/file.c          | 21 ++++++++++++---------
 fs/ufs/super.c           |  7 +++++++
 fs/utimes.c              | 17 +++++++++++++----
 fs/xfs/xfs_super.c       |  2 ++
 include/linux/fs.h       |  5 +++++
 include/linux/time64.h   |  2 ++
 52 files changed, 304 insertions(+), 78 deletions(-)