[PATCH v4 3/5] ext4: Initialize timestamps limits

From: Deepa Dinamani
Date: Fri Feb 24 2017 - 20:42:13 EST


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

Signed-off-by: Deepa Dinamani <deepa.kernel@xxxxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx>
Cc: linux-ext4@xxxxxxxxxxxxxxx
---
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 2bef0bd..7bac2cd 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1639,6 +1639,10 @@ 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 a673558..a77e11c 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3689,8 +3689,13 @@ 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