get_seconds() is deprecated in favor of ktime_get_real_seconds(),
which returns a 64-bit timestamp.
In the SYSV file system, the superblock timestamp is only 32 bits
wide, and it is used to check whether a file system is clean, so
the best solution seems to be to force a wraparound and explicitly
convert it to an unsigned 32-bit value.
This is independent of the inode timestamps that are also 32-bit
wide on disk and that come from current_time().
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
---
fs/sysv/inode.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/sysv/inode.c b/fs/sysv/inode.c
index bec9f79adb25..499a20a5a010 100644
--- a/fs/sysv/inode.c
+++ b/fs/sysv/inode.c
@@ -35,7 +35,7 @@
static int sysv_sync_fs(struct super_block *sb, int wait)
{
struct sysv_sb_info *sbi = SYSV_SB(sb);
- unsigned long time = get_seconds(), old_time;
+ u32 time = (u32)ktime_get_real_seconds(), old_time;
mutex_lock(&sbi->s_lock);
@@ -46,8 +46,8 @@ static int sysv_sync_fs(struct super_block *sb, int wait)
*/
old_time = fs32_to_cpu(sbi, *sbi->s_sb_time);
if (sbi->s_type == FSTYPE_SYSV4) {
- if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38 - old_time))
- *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38 - time);
+ if (*sbi->s_sb_state == cpu_to_fs32(sbi, 0x7c269d38u - old_time))
+ *sbi->s_sb_state = cpu_to_fs32(sbi, 0x7c269d38u - time);
*sbi->s_sb_time = cpu_to_fs32(sbi, time);
mark_buffer_dirty(sbi->s_bh2);
}
--
2.9.0
get_seconds() is deprecated because of the 32-bit overflow and will
be removed. All callers in ufs also truncate to a 32-bit number, so
nothing changes during the conversion, but this should be harmless as the
superblock and cylinder group timestamps are not visible to user space,
except for checking the fs-dirty state, wich works fine across the
overflow.
This moves the call to get_seconds() into a new inline function, with
a comment explaining the constraints, while converting it to
ktime_get_real_seconds().
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
---
fs/ufs/balloc.c | 4 ++--
fs/ufs/ialloc.c | 2 +-
fs/ufs/super.c | 4 ++--
fs/ufs/util.h | 14 ++++++++++++++
4 files changed, 19 insertions(+), 5 deletions(-)
diff --git a/fs/ufs/balloc.c b/fs/ufs/balloc.c
index e727ee07dbe4..075d3d9114c8 100644
--- a/fs/ufs/balloc.c
+++ b/fs/ufs/balloc.c
@@ -547,7 +547,7 @@ static u64 ufs_add_fragments(struct inode *inode, u64 fragment,
/*
* Block can be extended
*/
- ucg->cg_time = cpu_to_fs32(sb, get_seconds());
+ ucg->cg_time = ufs_get_seconds(sb);
for (i = newcount; i < (uspi->s_fpb - fragoff); i++)
if (ubh_isclr (UCPI_UBH(ucpi), ucpi->c_freeoff, fragno + i))
break;
@@ -639,7 +639,7 @@ static u64 ufs_alloc_fragments(struct inode *inode, unsigned cgno,
if (!ufs_cg_chkmagic(sb, ucg))
ufs_panic (sb, "ufs_alloc_fragments",
"internal error, bad magic number on cg %u", cgno);
- ucg->cg_time = cpu_to_fs32(sb, get_seconds());
+ ucg->cg_time = ufs_get_seconds(sb);
if (count == uspi->s_fpb) {
result = ufs_alloccg_block (inode, ucpi, goal, err);
diff --git a/fs/ufs/ialloc.c b/fs/ufs/ialloc.c
index e1ef0f0a1353..c678fff2a04d 100644
--- a/fs/ufs/ialloc.c
+++ b/fs/ufs/ialloc.c
@@ -89,7 +89,7 @@ void ufs_free_inode (struct inode * inode)
if (!ufs_cg_chkmagic(sb, ucg))
ufs_panic (sb, "ufs_free_fragments", "internal error, bad cg magic number");
- ucg->cg_time = cpu_to_fs32(sb, get_seconds());
+ ucg->cg_time = ufs_get_seconds(sb);
is_directory = S_ISDIR(inode->i_mode);
diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index 488088141451..a4e07e910f1b 100644
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -698,7 +698,7 @@ static int ufs_sync_fs(struct super_block *sb, int wait)
usb1 = ubh_get_usb_first(uspi);
usb3 = ubh_get_usb_third(uspi);
- usb1->fs_time = cpu_to_fs32(sb, get_seconds());
+ usb1->fs_time = ufs_get_seconds(sb);
if ((flags & UFS_ST_MASK) == UFS_ST_SUN ||
(flags & UFS_ST_MASK) == UFS_ST_SUNOS ||
(flags & UFS_ST_MASK) == UFS_ST_SUNx86)
@@ -1342,7 +1342,7 @@ static int ufs_remount (struct super_block *sb, int *mount_flags, char *data)
*/
if (*mount_flags & SB_RDONLY) {
ufs_put_super_internal(sb);
- usb1->fs_time = cpu_to_fs32(sb, get_seconds());
+ usb1->fs_time = ufs_get_seconds(sb);
if ((flags & UFS_ST_MASK) == UFS_ST_SUN
|| (flags & UFS_ST_MASK) == UFS_ST_SUNOS
|| (flags & UFS_ST_MASK) == UFS_ST_SUNx86)
diff --git a/fs/ufs/util.h b/fs/ufs/util.h
index 1907be6d5808..1fd3011ea623 100644
--- a/fs/ufs/util.h
+++ b/fs/ufs/util.h
@@ -590,3 +590,17 @@ static inline int ufs_is_data_ptr_zero(struct ufs_sb_private_info *uspi,
else
return *(__fs32 *)p == 0;
}
+
+static inline __fs32 ufs_get_seconds(struct super_block *sbp)
+{
+ time64_t now = ktime_get_real_seconds();
+
+ /* Signed 32-bit interpretation wraps around in 2038, which
+ * happens in ufs1 inode stamps but not ufs2 using 64-bits
+ * stamps. For superblock and blockgroup, let's assume
+ * unsigned 32-bit stamps, which are good until y2106.
+ * Wrap around rather than clamp here to make the dirty
+ * file system detection work in the superblock stamp.
+ */
+ return cpu_to_fs32(sbp, lower_32_bits(now));
+}
--
2.9.0
get_seconds() is deprecated because it will lead to a 32-bit overflow
in 2038 or 2106. We don't need the i_generation to be strictly
monotonic anyway, and other file systems like ext4 and xfs just use
prandom_u32(), so let's use the same one here.
If this is considered too slow, we could also use ktime_get_seconds()
or ktime_get_real_seconds() to keep the previous behavior.
Both of these return a time64_t and are not deprecated, but only
return a unique value once per second, and are predictable.
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
---
mm/shmem.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index 2cab84403055..387ae5323f56 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -29,6 +29,7 @@
#include <linux/pagemap.h>
#include <linux/file.h>
#include <linux/mm.h>
+#include <linux/random.h>
#include <linux/sched/signal.h>
#include <linux/export.h>
#include <linux/swap.h>
@@ -2187,7 +2188,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, const struct inode
inode_init_owner(inode, dir, mode);
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
- inode->i_generation = get_seconds();
+ inode->i_generation = prandom_u32();
info = SHMEM_I(inode);
memset(info, 0, (char *)inode - (char *)info);
spin_lock_init(&info->lock);
--
2.9.0
The handling of timestamps outside of the 1970..2038 range in the dlm
glue is rather inconsistent: on 32-bit architectures, this has always
wrapped around to negative timestamps in the 1902..1969 range, while on
64-bit kernels all timestamps are interpreted as positive 34 bit numbers
in the 1970..2514 year range.
Now that the VFS code handles 64-bit timestamps on all architectures,
we can make the behavior more consistent here, and return the same result
that we had on 64-bit already, making the file system y2038 safe in the
process. Outside of dlmglue, it already uses 64-bit on-disk timestamps
anway, so that part is fine.
For consistency, I'm changing ocfs2_pack_timespec() to clamp
anything outside of the supported range to the minimum and maximum
values. This avoids a possible ambiguity of values before 1970
in particular, which used to be interpreted as times at the end of the
2514 range previously.
Signed-off-by: Arnd Bergmann <arnd(a)arndb.de>
---
fs/ocfs2/dlmglue.c | 26 +++++++++-----------------
1 file changed, 9 insertions(+), 17 deletions(-)
diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 0ff424c6d17c..50610a9ed9f4 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -2121,10 +2121,10 @@ static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
/* LVB only has room for 64 bits of time here so we pack it for
* now. */
-static u64 ocfs2_pack_timespec(struct timespec *spec)
+static u64 ocfs2_pack_timespec(struct timespec64 *spec)
{
u64 res;
- u64 sec = spec->tv_sec;
+ u64 sec = clamp_t(time64_t, spec->tv_sec, 0, 0x3ffffffffull);
u32 nsec = spec->tv_nsec;
res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK);
@@ -2140,7 +2140,6 @@ static void __ocfs2_stuff_meta_lvb(struct inode *inode)
struct ocfs2_inode_info *oi = OCFS2_I(inode);
struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
struct ocfs2_meta_lvb *lvb;
- struct timespec ts;
lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
@@ -2161,15 +2160,12 @@ static void __ocfs2_stuff_meta_lvb(struct inode *inode)
lvb->lvb_igid = cpu_to_be32(i_gid_read(inode));
lvb->lvb_imode = cpu_to_be16(inode->i_mode);
lvb->lvb_inlink = cpu_to_be16(inode->i_nlink);
- ts = timespec64_to_timespec(inode->i_atime);
lvb->lvb_iatime_packed =
- cpu_to_be64(ocfs2_pack_timespec(&ts));
- ts = timespec64_to_timespec(inode->i_ctime);
+ cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime));
lvb->lvb_ictime_packed =
- cpu_to_be64(ocfs2_pack_timespec(&ts));
- ts = timespec64_to_timespec(inode->i_mtime);
+ cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime));
lvb->lvb_imtime_packed =
- cpu_to_be64(ocfs2_pack_timespec(&ts));
+ cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime));
lvb->lvb_iattr = cpu_to_be32(oi->ip_attr);
lvb->lvb_idynfeatures = cpu_to_be16(oi->ip_dyn_features);
lvb->lvb_igeneration = cpu_to_be32(inode->i_generation);
@@ -2178,7 +2174,7 @@ static void __ocfs2_stuff_meta_lvb(struct inode *inode)
mlog_meta_lvb(0, lockres);
}
-static void ocfs2_unpack_timespec(struct timespec *spec,
+static void ocfs2_unpack_timespec(struct timespec64 *spec,
u64 packed_time)
{
spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT;
@@ -2187,7 +2183,6 @@ static void ocfs2_unpack_timespec(struct timespec *spec,
static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
{
- struct timespec ts;
struct ocfs2_inode_info *oi = OCFS2_I(inode);
struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
struct ocfs2_meta_lvb *lvb;
@@ -2215,15 +2210,12 @@ static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
i_gid_write(inode, be32_to_cpu(lvb->lvb_igid));
inode->i_mode = be16_to_cpu(lvb->lvb_imode);
set_nlink(inode, be16_to_cpu(lvb->lvb_inlink));
- ocfs2_unpack_timespec(&ts,
+ ocfs2_unpack_timespec(&inode->i_atime,
be64_to_cpu(lvb->lvb_iatime_packed));
- inode->i_atime = timespec_to_timespec64(ts);
- ocfs2_unpack_timespec(&ts,
+ ocfs2_unpack_timespec(&inode->i_mtime,
be64_to_cpu(lvb->lvb_imtime_packed));
- inode->i_mtime = timespec_to_timespec64(ts);
- ocfs2_unpack_timespec(&ts,
+ ocfs2_unpack_timespec(&inode->i_ctime,
be64_to_cpu(lvb->lvb_ictime_packed));
- inode->i_ctime = timespec_to_timespec64(ts);
spin_unlock(&oi->ip_lock);
}
--
2.9.0
