[PATCH v8 00/20] vfs: Add support for timestamp limits

[PATCH v8 00/20] vfs: Add support for timestamp limits

[Deepa Dinamani]

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         1
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.

A test for checking file system timestamp limits has been posted
at https://www.spinics.net/lists/fstests/msg12262.html

Changes since v7:
* Dropped fat modifications from timespec_truncate patch
* Leverage timestamp_truncate function in utimes
* Added a fix for pstore ramoops timestamps
* Added ext4 warning for inodes without room for extended timestamps.
* Made mount warning more human readable
Changes since v6:
* No change in mount behavior because of expiry of timestamps.
* Included limits for more filesystems.
Changes since v5:
* Dropped y2038-specific changes
Changes since v4:
* Added documentation for boot param
Changes since v3:
* Remove redundant initializations in libfs.c
* Change early_param to __setup similar to other root mount options.
* Fix documentation warning
Changes since v2:
* Introduce early boot param override for checks.
* Drop afs patch for timestamp limits.
Changes since v1:
* return EROFS on mount errors
* fix mtime copy/paste error in utimes

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           | 10 +++++++++-
 fs/ext4/super.c          | 17 +++++++++++++++--
 fs/f2fs/file.c           | 21 ++++++++++++---------
 fs/fat/inode.c           | 12 ++++++++++++
 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        |  7 +++----
 fs/minix/inode.c         |  2 ++
 fs/namespace.c           | 33 ++++++++++++++++++++++++++++++++-
 fs/nfs/super.c           | 20 +++++++++++++++++++-
 fs/ntfs/inode.c          | 21 ++++++++++++---------
 fs/omfs/inode.c          |  4 ++++
 fs/orangefs/super.c      |  2 ++
 fs/pstore/ram.c          |  2 ++
 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              |  6 ++----
 fs/xfs/xfs_super.c       |  2 ++
 include/linux/fs.h       |  5 +++++
 include/linux/time64.h   |  2 ++
 51 files changed, 315 insertions(+), 78 deletions(-)

-- 
2.17.1

Cc: adilger.kernel@dilger.ca
Cc: adrian.hunter@intel.com
Cc: aivazian.tigran@gmail.com
Cc: al@alarsen.net
Cc: anna.schumaker@netapp.com
Cc: anton@enomsg.org
Cc: asmadeus@codewreck.org
Cc: ccross@android.com
Cc: ceph-devel@vger.kernel.org
Cc: coda@cs.cmu.edu
Cc: codalist@coda.cs.cmu.edu
Cc: darrick.wong@oracle.com
Cc: dedekind1@gmail.com
Cc: devel@lists.orangefs.org
Cc: dsterba@suse.com
Cc: dushistov@mail.ru
Cc: dwmw2@infradead.org
Cc: ericvh@gmail.com
Cc: gregkh@linuxfoundation.org
Cc: hch@infradead.org
Cc: hch@lst.de
Cc: hirofumi@mail.parknet.co.jp
Cc: hubcap@omnibond.com
Cc: idryomov@gmail.com
Cc: jack@suse.com
Cc: jaegeuk@kernel.org
Cc: jaharkes@cs.cmu.edu
Cc: jfs-discussion@lists.sourceforge.net
Cc: jlbec@evilplan.org
Cc: keescook@chromium.org
Cc: linux-cifs@vger.kernel.org
Cc: linux-ext4@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: linux-karma-devel@lists.sourceforge.net
Cc: linux-mtd@lists.infradead.org
Cc: linux-nfs@vger.kernel.org
Cc: linux-ntfs-dev@lists.sourceforge.net
Cc: linux-xfs@vger.kernel.org
Cc: lucho@ionkov.net
Cc: luisbg@kernel.org
Cc: martin@omnibond.com
Cc: me@bobcopeland.com
Cc: mikulas@artax.karlin.mff.cuni.cz
Cc: nico@fluxnic.net
Cc: phillip@squashfs.org.uk
Cc: reiserfs-devel@vger.kernel.org
Cc: richard@nod.at
Cc: sage@redhat.com
Cc: salah.triki@gmail.com
Cc: sfrench@samba.org
Cc: shaggy@kernel.org
Cc: tj@kernel.org
Cc: tony.luck@intel.com
Cc: trond.myklebust@hammerspace.com
Cc: tytso@mit.edu
Cc: v9fs-developer@lists.sourceforge.net
Cc: yuchao0@huawei.com
Cc: zyan@redhat.com

[PATCH v8 06/20] fs: Fill in max and min timestamps in superblock

[Deepa Dinamani]

Fill in the appropriate limits to avoid inconsistencies
in the vfs cached inode times when timestamps are
outside the permitted range.

Even though some filesystems are read-only, fill in the
timestamps to reflect the on-disk representation.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: aivazian.tigran@gmail.com
Cc: al@alarsen.net
Cc: coda@cs.cmu.edu
Cc: darrick.wong@oracle.com
Cc: dushistov@mail.ru
Cc: dwmw2@infradead.org
Cc: hch@infradead.org
Cc: jack@suse.com
Cc: jaharkes@cs.cmu.edu
Cc: luisbg@kernel.org
Cc: nico@fluxnic.net
Cc: phillip@squashfs.org.uk
Cc: richard@nod.at
Cc: salah.triki@gmail.com
Cc: shaggy@kernel.org
Cc: linux-xfs@vger.kernel.org
Cc: codalist@coda.cs.cmu.edu
Cc: linux-ext4@vger.kernel.org
Cc: linux-mtd@lists.infradead.org
Cc: jfs-discussion@lists.sourceforge.net
Cc: reiserfs-devel@vger.kernel.org
---
 fs/befs/linuxvfs.c       | 2 ++
 fs/bfs/inode.c           | 2 ++
 fs/coda/inode.c          | 3 +++
 fs/cramfs/inode.c        | 2 ++
 fs/efs/super.c           | 2 ++
 fs/ext2/super.c          | 2 ++
 fs/freevxfs/vxfs_super.c | 2 ++
 fs/jffs2/fs.c            | 3 +++
 fs/jfs/super.c           | 2 ++
 fs/minix/inode.c         | 2 ++
 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/ufs/super.c           | 7 +++++++
 fs/xfs/xfs_super.c       | 2 ++
 17 files changed, 42 insertions(+)

diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c
index 462d096ff3e9..64cdf4d8e424 100644
--- a/fs/befs/linuxvfs.c
+++ b/fs/befs/linuxvfs.c
@@ -893,6 +893,8 @@ befs_fill_super(struct super_block *sb, void *data, int silent)
 	sb_set_blocksize(sb, (ulong) befs_sb->block_size);
 	sb->s_op = &befs_sops;
 	sb->s_export_op = &befs_export_operations;
+	sb->s_time_min = 0;
+	sb->s_time_max = 0xffffffffffffll;
 	root = befs_iget(sb, iaddr2blockno(sb, &(befs_sb->root_dir)));
 	if (IS_ERR(root)) {
 		ret = PTR_ERR(root);
diff --git a/fs/bfs/inode.c b/fs/bfs/inode.c
index 5e97bed073d7..f8ce1368218b 100644
--- a/fs/bfs/inode.c
+++ b/fs/bfs/inode.c
@@ -324,6 +324,8 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent)
 		return -ENOMEM;
 	mutex_init(&info->bfs_lock);
 	s->s_fs_info = info;
+	s->s_time_min = 0;
+	s->s_time_max = U32_MAX;
 
 	sb_set_blocksize(s, BFS_BSIZE);
 
diff --git a/fs/coda/inode.c b/fs/coda/inode.c
index 59a9a29ade0a..e07b5f2ceccc 100644
--- a/fs/coda/inode.c
+++ b/fs/coda/inode.c
@@ -223,6 +223,9 @@ static int coda_fill_super(struct super_block *sb, struct fs_context *fc)
 	sb->s_magic = CODA_SUPER_MAGIC;
 	sb->s_op = &coda_super_operations;
 	sb->s_d_op = &coda_dentry_operations;
+	sb->s_time_gran = 1;
+	sb->s_time_min = S64_MIN;
+	sb->s_time_max = S64_MAX;
 
 	error = super_setup_bdi(sb);
 	if (error)
diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c
index 2ee89a353d64..c304ae8357ef 100644
--- a/fs/cramfs/inode.c
+++ b/fs/cramfs/inode.c
@@ -599,6 +599,8 @@ static int cramfs_finalize_super(struct super_block *sb,
 
 	/* Set it all up.. */
 	sb->s_flags |= SB_RDONLY;
+	sb->s_time_min = 0;
+	sb->s_time_max = 0;
 	sb->s_op = &cramfs_ops;
 	root = get_cramfs_inode(sb, cramfs_root, 0);
 	if (IS_ERR(root))
diff --git a/fs/efs/super.c b/fs/efs/super.c
index 867fc24dee20..4a6ebff2af76 100644
--- a/fs/efs/super.c
+++ b/fs/efs/super.c
@@ -257,6 +257,8 @@ static int efs_fill_super(struct super_block *s, void *d, int silent)
 	if (!sb)
 		return -ENOMEM;
 	s->s_fs_info = sb;
+	s->s_time_min = 0;
+	s->s_time_max = U32_MAX;
  
 	s->s_magic		= EFS_SUPER_MAGIC;
 	if (!sb_set_blocksize(s, EFS_BLOCKSIZE)) {
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 44eb6e7eb492..baa36c6fb71e 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -1002,6 +1002,8 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
 
 	sb->s_maxbytes = ext2_max_size(sb->s_blocksize_bits);
 	sb->s_max_links = EXT2_LINK_MAX;
+	sb->s_time_min = S32_MIN;
+	sb->s_time_max = S32_MAX;
 
 	if (le32_to_cpu(es->s_rev_level) == EXT2_GOOD_OLD_REV) {
 		sbi->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
diff --git a/fs/freevxfs/vxfs_super.c b/fs/freevxfs/vxfs_super.c
index a89f68c3cbed..578a5062706e 100644
--- a/fs/freevxfs/vxfs_super.c
+++ b/fs/freevxfs/vxfs_super.c
@@ -229,6 +229,8 @@ static int vxfs_fill_super(struct super_block *sbp, void *dp, int silent)
 
 	sbp->s_op = &vxfs_super_ops;
 	sbp->s_fs_info = infp;
+	sbp->s_time_min = 0;
+	sbp->s_time_max = U32_MAX;
 
 	if (!vxfs_try_sb_magic(sbp, silent, 1,
 			(__force __fs32)cpu_to_le32(VXFS_SUPER_MAGIC))) {
diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c
index 25736676a456..05fe6cf5f1ac 100644
--- a/fs/jffs2/fs.c
+++ b/fs/jffs2/fs.c
@@ -591,6 +591,9 @@ int jffs2_do_fill_super(struct super_block *sb, struct fs_context *fc)
 	sb->s_blocksize = PAGE_SIZE;
 	sb->s_blocksize_bits = PAGE_SHIFT;
 	sb->s_magic = JFFS2_SUPER_MAGIC;
+	sb->s_time_min = 0;
+	sb->s_time_max = U32_MAX;
+
 	if (!sb_rdonly(sb))
 		jffs2_start_garbage_collect_thread(c);
 	return 0;
diff --git a/fs/jfs/super.c b/fs/jfs/super.c
index f4e10cb9f734..b2dc4d1f9dcc 100644
--- a/fs/jfs/super.c
+++ b/fs/jfs/super.c
@@ -503,6 +503,8 @@ static int jfs_fill_super(struct super_block *sb, void *data, int silent)
 
 	sb->s_fs_info = sbi;
 	sb->s_max_links = JFS_LINK_MAX;
+	sb->s_time_min = 0;
+	sb->s_time_max = U32_MAX;
 	sbi->sb = sb;
 	sbi->uid = INVALID_UID;
 	sbi->gid = INVALID_GID;
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index f96073f25432..7cb5fd38eb14 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -277,6 +277,8 @@ static int minix_fill_super(struct super_block *s, void *data, int silent)
 
 	/* set up enough so that it can read an inode */
 	s->s_op = &minix_sops;
+	s->s_time_min = 0;
+	s->s_time_max = U32_MAX;
 	root_inode = minix_iget(s, MINIX_ROOT_INO);
 	if (IS_ERR(root_inode)) {
 		ret = PTR_ERR(root_inode);
diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c
index 922d083bbc7c..e8da1cde87b9 100644
--- a/fs/qnx4/inode.c
+++ b/fs/qnx4/inode.c
@@ -201,6 +201,8 @@ static int qnx4_fill_super(struct super_block *s, void *data, int silent)
 	s->s_op = &qnx4_sops;
 	s->s_magic = QNX4_SUPER_MAGIC;
 	s->s_flags |= SB_RDONLY;	/* Yup, read-only yet */
+	s->s_time_min = 0;
+	s->s_time_max = U32_MAX;
 
 	/* Check the superblock signature. Since the qnx4 code is
 	   dangerous, we should leave as quickly as possible
diff --git a/fs/qnx6/inode.c b/fs/qnx6/inode.c
index 0f8b0ff1ba43..345db56c98fd 100644
--- a/fs/qnx6/inode.c
+++ b/fs/qnx6/inode.c
@@ -429,6 +429,8 @@ static int qnx6_fill_super(struct super_block *s, void *data, int silent)
 	s->s_op = &qnx6_sops;
 	s->s_magic = QNX6_SUPER_MAGIC;
 	s->s_flags |= SB_RDONLY;        /* Yup, read-only yet */
+	s->s_time_min = 0;
+	s->s_time_max = U32_MAX;
 
 	/* ease the later tree level calculations */
 	sbi = QNX6_SB(s);
diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index ab028ea0e561..d69b4ac0ae2f 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -1976,6 +1976,9 @@ static int reiserfs_fill_super(struct super_block *s, void *data, int silent)
 		goto error_unlocked;
 	}
 
+	s->s_time_min = 0;
+	s->s_time_max = U32_MAX;
+
 	rs = SB_DISK_SUPER_BLOCK(s);
 	/*
 	 * Let's do basic sanity check to verify that underlying device is not
diff --git a/fs/romfs/super.c b/fs/romfs/super.c
index 4636f867b9e8..338ac8521e65 100644
--- a/fs/romfs/super.c
+++ b/fs/romfs/super.c
@@ -477,6 +477,8 @@ static int romfs_fill_super(struct super_block *sb, struct fs_context *fc)
 	sb->s_maxbytes = 0xFFFFFFFF;
 	sb->s_magic = ROMFS_MAGIC;
 	sb->s_flags |= SB_RDONLY | SB_NOATIME;
+	sb->s_time_min = 0;
+	sb->s_time_max = 0;
 	sb->s_op = &romfs_super_ops;
 
 #ifdef CONFIG_ROMFS_ON_MTD
diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index 0311171af72d..e2d6566371ec 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -186,6 +186,8 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc)
 		(u64) le64_to_cpu(sblk->id_table_start));
 
 	sb->s_maxbytes = MAX_LFS_FILESIZE;
+	sb->s_time_min = 0;
+	sb->s_time_max = U32_MAX;
 	sb->s_flags |= SB_RDONLY;
 	sb->s_op = &squashfs_super_ops;
 
diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index 4ed0dca52ec8..1da0be667409 100644
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -843,6 +843,10 @@ static int ufs_fill_super(struct super_block *sb, void *data, int silent)
 
 	sb->s_maxbytes = MAX_LFS_FILESIZE;
 
+	sb->s_time_gran = NSEC_PER_SEC;
+	sb->s_time_min = S32_MIN;
+	sb->s_time_max = S32_MAX;
+
 	switch (sbi->s_mount_opt & UFS_MOUNT_UFSTYPE) {
 	case UFS_MOUNT_UFSTYPE_44BSD:
 		UFSD("ufstype=44bsd\n");
@@ -861,6 +865,9 @@ static int ufs_fill_super(struct super_block *sb, void *data, int silent)
 		uspi->s_fshift = 9;
 		uspi->s_sbsize = super_block_size = 1536;
 		uspi->s_sbbase =  0;
+		sb->s_time_gran = 1;
+		sb->s_time_min = S64_MIN;
+		sb->s_time_max = S64_MAX;
 		flags |= UFS_TYPE_UFS2 | UFS_DE_44BSD | UFS_UID_44BSD | UFS_ST_44BSD | UFS_CG_44BSD;
 		break;
 		
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index f9450235533c..d3b10900fc24 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1663,6 +1663,8 @@ xfs_fs_fill_super(
 	sb->s_maxbytes = xfs_max_file_offset(sb->s_blocksize_bits);
 	sb->s_max_links = XFS_MAXLINK;
 	sb->s_time_gran = 1;
+	sb->s_time_min = S32_MIN;
+	sb->s_time_max = S32_MAX;
 	sb->s_iflags |= SB_I_CGROUPWB;
 
 	set_posix_acl_flag(sb);
-- 
2.17.1

[PATCH v8 09/20] ext4: Initialize timestamps limits

[Deepa Dinamani]

ext4 has different overflow limits for max filesystem
timestamps based on the extra bytes available.

The timestamp limits are calculated according to the
encoding table in
a4dad1ae24f85i(ext4: Fix handling of extended tv_sec):

* extra  msb of                         adjust for signed
* epoch  32-bit                         32-bit tv_sec to
* bits   time    decoded 64-bit tv_sec  64-bit tv_sec      valid time range
* 0 0    1    -0x80000000..-0x00000001  0x000000000   1901-12-13..1969-12-31
* 0 0    0    0x000000000..0x07fffffff  0x000000000   1970-01-01..2038-01-19
* 0 1    1    0x080000000..0x0ffffffff  0x100000000   2038-01-19..2106-02-07
* 0 1    0    0x100000000..0x17fffffff  0x100000000   2106-02-07..2174-02-25
* 1 0    1    0x180000000..0x1ffffffff  0x200000000   2174-02-25..2242-03-16
* 1 0    0    0x200000000..0x27fffffff  0x200000000   2242-03-16..2310-04-04
* 1 1    1    0x280000000..0x2ffffffff  0x300000000   2310-04-04..2378-04-22
* 1 1    0    0x300000000..0x37fffffff  0x300000000   2378-04-22..2446-05-10

Note that the time limits are not correct for deletion times.

Added a warn when an inode cannot be extended to incorporate an
extended timestamp.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Cc: tytso@mit.edu
Cc: adilger.kernel@dilger.ca
Cc: linux-ext4@vger.kernel.org
---
 fs/ext4/ext4.h  | 10 +++++++++-
 fs/ext4/super.c | 17 +++++++++++++++--
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 9c7f4036021b..ae5d0c86aba2 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -832,11 +832,15 @@ static inline void ext4_decode_extra_time(struct timespec64 *time,
 
 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)				\
 do {										\
-	(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);		\
 	if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     {\
+		(raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);	\
 		(raw_inode)->xtime ## _extra =					\
 				ext4_encode_extra_time(&(inode)->xtime);	\
 		}								\
+	else	{\
+		(raw_inode)->xtime = cpu_to_le32(clamp_t(int32_t, (inode)->xtime.tv_sec, S32_MIN, S32_MAX));	\
+		ext4_warning_inode(inode, "inode does not support timestamps beyond 2038"); \
+	} \
 } while (0)
 
 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)			       \
@@ -1643,6 +1647,10 @@ static inline bool ext4_verity_in_progress(struct inode *inode)
 
 #define EXT4_GOOD_OLD_INODE_SIZE 128
 
+#define EXT4_EXTRA_TIMESTAMP_MAX	(((s64)1 << 34) - 1  + S32_MIN)
+#define EXT4_NON_EXTRA_TIMESTAMP_MAX	S32_MAX
+#define EXT4_TIMESTAMP_MIN		S32_MIN
+
 /*
  * Feature set definitions
  */
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 27cd622676e7..3db5f17228b7 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4039,8 +4039,21 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 			       sbi->s_inode_size);
 			goto failed_mount;
 		}
-		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
-			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
+		/*
+		 * i_atime_extra is the last extra field available for [acm]times in
+		 * struct ext4_inode. Checking for that field should suffice to ensure
+		 * we have extra space for all three.
+		 */
+		if (sbi->s_inode_size >= offsetof(struct ext4_inode, i_atime_extra) +
+			sizeof(((struct ext4_inode *)0)->i_atime_extra)) {
+			sb->s_time_gran = 1;
+			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
+		} else {
+			sb->s_time_gran = NSEC_PER_SEC;
+			sb->s_time_max = EXT4_NON_EXTRA_TIMESTAMP_MAX;
+		}
+
+		sb->s_time_min = EXT4_TIMESTAMP_MIN;
 	}
 
 	sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
-- 
2.17.1

Re: [PATCH v8 00/20] vfs: Add support for timestamp limits

[Jeff Layton]

On Sun, 2019-08-18 at 09:57 -0700, Deepa Dinamani wrote:
> 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         1
> 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

Looks reasonable, overall.

Note that the granularity changed recently for cephfs. See commit
0f7cf80ae96c2a (ceph: initialize superblock s_time_gran to 1).

In any case, you can add my Acked-by

-- 
Jeff Layton <jlayton@kernel.org>

Re: [PATCH v8 06/20] fs: Fill in max and min timestamps in superblock

[Anders Larsen]

On Sunday, 2019-08-18 18:58 Deepa Dinamani wrote:
> Fill in the appropriate limits to avoid inconsistencies
> in the vfs cached inode times when timestamps are
> outside the permitted range.
> 
> Even though some filesystems are read-only, fill in the
> timestamps to reflect the on-disk representation.
> 
> Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
> Cc: aivazian.tigran@gmail.com
> Cc: al@alarsen.net
> Cc: coda@cs.cmu.edu
> Cc: darrick.wong@oracle.com
> Cc: dushistov@mail.ru
> Cc: dwmw2@infradead.org
> Cc: hch@infradead.org
> Cc: jack@suse.com
> Cc: jaharkes@cs.cmu.edu
> Cc: luisbg@kernel.org
> Cc: nico@fluxnic.net
> Cc: phillip@squashfs.org.uk
> Cc: richard@nod.at
> Cc: salah.triki@gmail.com
> Cc: shaggy@kernel.org
> Cc: linux-xfs@vger.kernel.org
> Cc: codalist@coda.cs.cmu.edu
> Cc: linux-ext4@vger.kernel.org
> Cc: linux-mtd@lists.infradead.org
> Cc: jfs-discussion@lists.sourceforge.net
> Cc: reiserfs-devel@vger.kernel.org
> ---
>  fs/befs/linuxvfs.c       | 2 ++
>  fs/bfs/inode.c           | 2 ++
>  fs/coda/inode.c          | 3 +++
>  fs/cramfs/inode.c        | 2 ++
>  fs/efs/super.c           | 2 ++
>  fs/ext2/super.c          | 2 ++
>  fs/freevxfs/vxfs_super.c | 2 ++
>  fs/jffs2/fs.c            | 3 +++
>  fs/jfs/super.c           | 2 ++
>  fs/minix/inode.c         | 2 ++
>  fs/qnx4/inode.c          | 2 ++

wrt qnx4, feel free to add
Acked-by: Anders Larsen <al@alarsen.net>