[RFC 4/6] ext4: Initialize timestamps limits

[RFC 4/6] ext4: Initialize timestamps limits

[Deepa Dinamani]

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

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org
---
 fs/ext4/ext4.h  | 4 ++++
 fs/ext4/super.c | 7 ++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index aff204f..e15c081 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1636,6 +1636,10 @@ static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
 
 #define EXT4_GOOD_OLD_INODE_SIZE 128
 
+#define EXT4_EXTRA_TIMESTAMP_MAX	(((s64)1 << 34) - 1  + S32_MIN)
+#define EXT4_NON_EXTRA_TIMESTAMP_MAX	Y2038_EXPIRY_TIMESTAMP
+#define EXT4_TIMESTAMP_MIN		S32_MIN
+
 /*
  * Feature set definitions
  */
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 72b459d..0519c52 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3672,8 +3672,13 @@ 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)
+		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
+			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
+		} else
+			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);
-- 
2.7.4

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[RFC 0/6] vfs: Add timestamp range check support

[Deepa Dinamani]

The series is aimed at adding timestamp checking and policy
related to it to vfs.

The series was developed with discussions and guidance from
Arnd Bergmann.

The original idea for the series was the discussion:
https://lkml.org/lkml/2014/5/30/551

Patches 5 and 6 can be merged only after vfs is transitioned
to use 64 bit timestamps as noted in the respective commit
texts.

The series only includes adding range limits to filesystems:
ext4 and afs as examples to keep the series simple.
Every filesystem will be updated to add these limits.

There is an ext4 current_time() api replacement patch that the
series depends on:
https://lkml.org/lkml/2016/6/9/38 .
This needs reposting to the mailing list.

The branch for the tree along with dependency can be found at

https://github.com/deepa-hub/vfs.git refs/heads/vfs_timestamp_policy

Deepa Dinamani (6):
  vfs: Add file timestamp range support
  vfs: Add checks for filesystem timestamp limits
  afs: Add time limits in the super block
  ext4: Initialize timestamps limits
  vfs: Add timestamp_truncate() api
  utimes: Clamp the timestamps before update

 fs/afs/super.c          |  2 ++
 fs/ext4/ext4.h          |  4 ++++
 fs/ext4/super.c         |  7 ++++++-
 fs/inode.c              | 37 ++++++++++++++++++++++++++++++++++++-
 fs/internal.h           |  2 ++
 fs/libfs.c              |  4 ++++
 fs/namespace.c          | 12 ++++++++++++
 fs/super.c              |  8 ++++++++
 fs/utimes.c             | 17 +++++++++++++----
 include/linux/fs.h      |  4 ++++
 include/linux/time64.h  |  6 ++++++
 include/uapi/linux/fs.h |  6 +++++-
 kernel/sysctl.c         |  7 +++++++
 13 files changed, 109 insertions(+), 7 deletions(-)

-- 
2.7.4

Cc: linux-afs@lists.infradead.org
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org


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[RFC 4/6] ext4: Initialize timestamps limits

[Deepa Dinamani]

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

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org
---
 fs/ext4/ext4.h  | 4 ++++
 fs/ext4/super.c | 7 ++++++-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 6789379..fca339a 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1635,6 +1635,10 @@ static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
 
 #define EXT4_GOOD_OLD_INODE_SIZE 128
 
+#define EXT4_EXTRA_TIMESTAMP_MAX	(((s64)1 << 34) - 1  + S32_MIN)
+#define EXT4_NON_EXTRA_TIMESTAMP_MAX	Y2038_EXPIRY_TIMESTAMP
+#define EXT4_TIMESTAMP_MIN		S32_MIN
+
 /*
  * Feature set definitions
  */
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index ab00bff..ebd039d 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3633,8 +3633,13 @@ 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)
+		if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
 			sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
+			sb->s_time_max = EXT4_EXTRA_TIMESTAMP_MAX;
+		} else
+			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);
-- 
2.7.4

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