* [PATCH v2 00/24] Delete CURRENT_TIME and CURRENT_TIME_SEC macros
@ 2016-06-20 0:26 Deepa Dinamani
2016-06-20 0:27 ` [PATCH v2 18/24] fs: nfs: Make nfs boot time y2038 safe Deepa Dinamani
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Deepa Dinamani @ 2016-06-20 0:26 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel
Cc: arnd, tglx, torvalds, tytso, viro, y2038, adilger.kernel,
adrian.hunter, anna.schumaker, buchino, ceph-devel, clm,
cm224.lee, dedekind1, dsterba, elder, eparis, gregkh, hiralpat,
idryomov, jack, jaegeuk, jbacik, jejb, jfs-discussion, jlbec,
john.stultz, linux-audit, linux-btrfs, linux-ext4,
linux-f2fs-devel, linux-mtd, linux-nfs, linux-scsi, lustre-devel,
martin.petersen, mfasheh, ocfs2-devel, paul, sage, sfrench,
shaggy, sramars, trond.myklebust, zyan
The series is aimed at getting rid of CURRENT_TIME and CURRENT_TIME_SEC macros.
The macros are not y2038 safe. There is no plan to transition them into being
y2038 safe.
ktime_get_* api's can be used in their place. And, these are y2038 safe.
Thanks to Arnd Bergmann for all the guidance and discussions.
Patches 2-4 were mostly generated using coccinelle scripts.
All filesystem timestamps use current_fs_time() for right granularity as
mentioned in the respective commit texts of patches. This has a changed
signature, renamed to current_time() and moved to the fs/inode.c.
This series also serves as a preparatory series to transition vfs to 64 bit
timestamps as outlined here: https://lkml.org/lkml/2016/2/12/104 .
As per Linus's suggestion in https://lkml.org/lkml/2016/5/24/663 , all the
inode timestamp changes have been squashed into a single patch. Also,
current_time() now is used as a single generic vfs filesystem timestamp api.
It also takes struct inode* as argument instead of struct super_block*.
Posting all patches together in a bigger series so that the big picture is
clear.
As per the suggestion in https://lwn.net/Articles/672598/, CURRENT_TIME macro
bug fixes are being handled in a series separate from transitioning vfs to use.
Changes from v1:
* Change current_fs_time(struct super_block *) to current_time(struct inode *)
* Note that change to add time64_to_tm() is already part of John's
kernel tree: https://lkml.org/lkml/2016/6/17/875 .
Deepa Dinamani (24):
vfs: Add current_time() api
fs: Replace CURRENT_TIME with current_time() for inode timestamps
fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
fs: Replace current_fs_time() with current_time()
fs: jfs: Replace CURRENT_TIME_SEC by current_time()
fs: ext4: Use current_time() for inode timestamps
fs: ubifs: Replace CURRENT_TIME_SEC with current_time
fs: btrfs: Use ktime_get_real_ts for root ctime
fs: udf: Replace CURRENT_TIME with current_time()
fs: cifs: Replace CURRENT_TIME by current_time()
fs: cifs: Replace CURRENT_TIME with ktime_get_real_ts()
fs: cifs: Replace CURRENT_TIME by get_seconds
fs: f2fs: Use ktime_get_real_seconds for sit_info times
drivers: staging: lustre: Replace CURRENT_TIME with current_time()
fs: ocfs2: Use time64_t to represent orphan scan times
fs: ocfs2: Replace CURRENT_TIME with ktime_get_real_seconds()
audit: Use timespec64 to represent audit timestamps
fs: nfs: Make nfs boot time y2038 safe
fnic: Use time64_t to represent trace timestamps
block: Replace CURRENT_TIME with ktime_get_real_ts
libceph: Replace CURRENT_TIME with ktime_get_real_ts
fs: ceph: Replace current_fs_time for request stamp
time: Delete CURRENT_TIME_SEC and CURRENT_TIME macro
time: Delete current_fs_time() function
arch/powerpc/platforms/cell/spufs/inode.c | 2 +-
arch/s390/hypfs/inode.c | 4 ++--
drivers/block/rbd.c | 2 +-
drivers/char/sonypi.c | 2 +-
drivers/infiniband/hw/qib/qib_fs.c | 2 +-
drivers/misc/ibmasm/ibmasmfs.c | 2 +-
drivers/oprofile/oprofilefs.c | 2 +-
drivers/platform/x86/sony-laptop.c | 2 +-
drivers/scsi/fnic/fnic_trace.c | 4 ++--
drivers/scsi/fnic/fnic_trace.h | 2 +-
drivers/staging/lustre/lustre/llite/llite_lib.c | 16 ++++++-------
drivers/staging/lustre/lustre/llite/namei.c | 4 ++--
drivers/staging/lustre/lustre/mdc/mdc_reint.c | 6 ++---
.../lustre/lustre/obdclass/linux/linux-obdo.c | 6 ++---
drivers/staging/lustre/lustre/obdclass/obdo.c | 6 ++---
drivers/staging/lustre/lustre/osc/osc_io.c | 2 +-
drivers/usb/core/devio.c | 18 +++++++-------
drivers/usb/gadget/function/f_fs.c | 8 +++----
drivers/usb/gadget/legacy/inode.c | 2 +-
fs/9p/vfs_inode.c | 2 +-
fs/adfs/inode.c | 2 +-
fs/affs/amigaffs.c | 6 ++---
fs/affs/inode.c | 2 +-
fs/attr.c | 2 +-
fs/autofs4/inode.c | 2 +-
fs/autofs4/root.c | 6 ++---
fs/bad_inode.c | 2 +-
fs/bfs/dir.c | 14 +++++------
fs/binfmt_misc.c | 2 +-
fs/btrfs/file.c | 6 ++---
fs/btrfs/inode.c | 22 ++++++++---------
fs/btrfs/ioctl.c | 8 +++----
fs/btrfs/root-tree.c | 3 ++-
fs/btrfs/transaction.c | 4 ++--
fs/btrfs/xattr.c | 2 +-
fs/ceph/file.c | 4 ++--
fs/ceph/inode.c | 2 +-
fs/ceph/mds_client.c | 4 +++-
fs/ceph/xattr.c | 2 +-
fs/cifs/cifsencrypt.c | 4 +++-
fs/cifs/cifssmb.c | 10 ++++----
fs/cifs/file.c | 4 ++--
fs/cifs/inode.c | 28 ++++++++++++----------
fs/coda/dir.c | 2 +-
fs/coda/file.c | 2 +-
fs/coda/inode.c | 2 +-
fs/configfs/inode.c | 6 ++---
fs/debugfs/inode.c | 2 +-
fs/devpts/inode.c | 6 ++---
fs/efivarfs/inode.c | 2 +-
fs/exofs/dir.c | 6 ++---
fs/exofs/inode.c | 4 ++--
fs/exofs/namei.c | 6 ++---
fs/ext2/acl.c | 2 +-
fs/ext2/dir.c | 6 ++---
fs/ext2/ialloc.c | 2 +-
fs/ext2/inode.c | 4 ++--
fs/ext2/ioctl.c | 4 ++--
fs/ext2/namei.c | 6 ++---
fs/ext2/super.c | 2 +-
fs/ext2/xattr.c | 2 +-
fs/ext4/acl.c | 2 +-
fs/ext4/ext4.h | 6 -----
fs/ext4/extents.c | 10 ++++----
fs/ext4/ialloc.c | 2 +-
fs/ext4/inline.c | 4 ++--
fs/ext4/inode.c | 6 ++---
fs/ext4/ioctl.c | 8 +++----
fs/ext4/namei.c | 24 ++++++++++---------
fs/ext4/super.c | 2 +-
fs/ext4/xattr.c | 2 +-
fs/f2fs/dir.c | 8 +++----
fs/f2fs/file.c | 8 +++----
fs/f2fs/inline.c | 2 +-
fs/f2fs/namei.c | 12 +++++-----
fs/f2fs/segment.c | 2 +-
fs/f2fs/segment.h | 5 ++--
fs/f2fs/xattr.c | 2 +-
fs/fat/dir.c | 2 +-
fs/fat/file.c | 6 ++---
fs/fat/inode.c | 2 +-
fs/fat/namei_msdos.c | 12 +++++-----
fs/fat/namei_vfat.c | 10 ++++----
fs/fuse/control.c | 2 +-
fs/fuse/dir.c | 2 +-
fs/gfs2/bmap.c | 8 +++----
fs/gfs2/dir.c | 12 +++++-----
fs/gfs2/inode.c | 8 +++----
fs/gfs2/quota.c | 2 +-
fs/gfs2/xattr.c | 8 +++----
fs/hfs/catalog.c | 8 +++----
fs/hfs/dir.c | 2 +-
fs/hfs/inode.c | 2 +-
fs/hfsplus/catalog.c | 8 +++----
fs/hfsplus/dir.c | 6 ++---
fs/hfsplus/inode.c | 2 +-
fs/hfsplus/ioctl.c | 2 +-
fs/hugetlbfs/inode.c | 10 ++++----
fs/inode.c | 21 +++++++++++++---
fs/jffs2/acl.c | 2 +-
fs/jffs2/fs.c | 2 +-
fs/jfs/acl.c | 2 +-
fs/jfs/inode.c | 2 +-
fs/jfs/ioctl.c | 2 +-
fs/jfs/jfs_inode.c | 2 +-
fs/jfs/namei.c | 24 +++++++++----------
fs/jfs/super.c | 2 +-
fs/jfs/xattr.c | 2 +-
fs/kernfs/inode.c | 2 +-
fs/libfs.c | 14 +++++------
fs/locks.c | 2 +-
fs/logfs/dir.c | 6 ++---
fs/logfs/file.c | 2 +-
fs/logfs/inode.c | 4 ++--
fs/logfs/readwrite.c | 4 ++--
fs/minix/bitmap.c | 2 +-
fs/minix/dir.c | 6 ++---
fs/minix/itree_common.c | 4 ++--
fs/minix/namei.c | 4 ++--
fs/nfs/client.c | 2 +-
fs/nfs/netns.h | 2 +-
fs/nfs/nfs4proc.c | 10 ++++----
fs/nfs/nfs4xdr.c | 2 +-
fs/nfsd/blocklayout.c | 2 +-
fs/nilfs2/dir.c | 6 ++---
fs/nilfs2/inode.c | 4 ++--
fs/nilfs2/ioctl.c | 2 +-
fs/nilfs2/namei.c | 6 ++---
fs/nsfs.c | 2 +-
fs/ntfs/inode.c | 2 +-
fs/ntfs/mft.c | 2 +-
fs/ocfs2/acl.c | 2 +-
fs/ocfs2/alloc.c | 2 +-
fs/ocfs2/aops.c | 2 +-
fs/ocfs2/cluster/heartbeat.c | 2 +-
fs/ocfs2/dir.c | 4 ++--
fs/ocfs2/dlmfs/dlmfs.c | 4 ++--
fs/ocfs2/file.c | 12 +++++-----
fs/ocfs2/inode.c | 2 +-
fs/ocfs2/journal.c | 4 ++--
fs/ocfs2/move_extents.c | 2 +-
fs/ocfs2/namei.c | 16 +++++++------
fs/ocfs2/ocfs2.h | 2 +-
fs/ocfs2/refcounttree.c | 4 ++--
fs/ocfs2/super.c | 2 +-
fs/ocfs2/xattr.c | 2 +-
fs/omfs/dir.c | 4 ++--
fs/omfs/inode.c | 2 +-
fs/openpromfs/inode.c | 2 +-
fs/orangefs/file.c | 2 +-
fs/orangefs/inode.c | 2 +-
fs/orangefs/namei.c | 10 ++++----
fs/pipe.c | 2 +-
fs/posix_acl.c | 2 +-
fs/proc/base.c | 2 +-
fs/proc/inode.c | 4 ++--
fs/proc/proc_sysctl.c | 2 +-
fs/proc/self.c | 2 +-
fs/proc/thread_self.c | 2 +-
fs/pstore/inode.c | 2 +-
fs/ramfs/inode.c | 6 ++---
fs/reiserfs/inode.c | 2 +-
fs/reiserfs/ioctl.c | 4 ++--
fs/reiserfs/namei.c | 12 +++++-----
fs/reiserfs/stree.c | 8 +++----
fs/reiserfs/super.c | 2 +-
fs/reiserfs/xattr.c | 6 ++---
fs/reiserfs/xattr_acl.c | 2 +-
fs/sysv/dir.c | 6 ++---
fs/sysv/ialloc.c | 2 +-
fs/sysv/itree.c | 4 ++--
fs/sysv/namei.c | 4 ++--
fs/tracefs/inode.c | 2 +-
fs/ubifs/dir.c | 10 ++++----
fs/ubifs/file.c | 12 +++++-----
fs/ubifs/ioctl.c | 2 +-
fs/ubifs/misc.h | 10 --------
fs/ubifs/sb.c | 14 +++++++----
fs/ubifs/xattr.c | 6 ++---
fs/udf/ialloc.c | 2 +-
fs/udf/inode.c | 4 ++--
fs/udf/namei.c | 20 ++++++++--------
fs/udf/super.c | 9 +++++--
fs/ufs/dir.c | 6 ++---
fs/ufs/ialloc.c | 8 ++++---
fs/ufs/inode.c | 6 ++---
fs/ufs/namei.c | 6 ++---
fs/xfs/xfs_acl.c | 2 +-
fs/xfs/xfs_inode.c | 2 +-
fs/xfs/xfs_iops.c | 2 +-
fs/xfs/xfs_trans_inode.c | 2 +-
include/linux/audit.h | 4 ++--
include/linux/fs.h | 2 +-
include/linux/time.h | 3 ---
ipc/mqueue.c | 18 +++++++-------
kernel/audit.c | 10 ++++----
kernel/audit.h | 2 +-
kernel/auditsc.c | 6 ++---
kernel/bpf/inode.c | 2 +-
kernel/time/time.c | 14 -----------
mm/shmem.c | 20 ++++++++--------
net/ceph/messenger.c | 6 +++--
net/ceph/osd_client.c | 4 ++--
net/sunrpc/rpc_pipe.c | 2 +-
security/inode.c | 2 +-
security/selinux/selinuxfs.c | 2 +-
206 files changed, 533 insertions(+), 522 deletions(-)
--
1.9.1
Cc: adilger.kernel@dilger.ca
Cc: adrian.hunter@intel.com
Cc: anna.schumaker@netapp.com
Cc: buchino@cisco.com
Cc: ceph-devel@vger.kernel.org
Cc: clm@fb.com
Cc: cm224.lee@samsung.com
Cc: dedekind1@gmail.com
Cc: dsterba@suse.com
Cc: elder@kernel.org
Cc: eparis@redhat.com
Cc: gregkh@linuxfoundation.org
Cc: hiralpat@cisco.com
Cc: idryomov@gmail.com
Cc: jack@suse.com
Cc: jaegeuk@kernel.org
Cc: jbacik@fb.com
Cc: jejb@linux.vnet.ibm.com
Cc: jfs-discussion@lists.sourceforge.net
Cc: jlbec@evilplan.org
Cc: john.stultz@linaro.org
Cc: linux-audit@redhat.com
Cc: linux-btrfs@vger.kernel.org
Cc: linux-ext4@vger.kernel.org
Cc: linux-f2fs-devel@lists.sourceforge.net
Cc: linux-mtd@lists.infradead.org
Cc: linux-nfs@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: lustre-devel@lists.lustre.org
Cc: martin.petersen@oracle.com
Cc: mfasheh@suse.com
Cc: ocfs2-devel@oss.oracle.com
Cc: paul@paul-moore.com
Cc: sage@redhat.com
Cc: sfrench@samba.org
Cc: shaggy@kernel.org
Cc: sramars@cisco.com
Cc: trond.myklebust@primarydata.com
Cc: zyan@redhat.com
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2 18/24] fs: nfs: Make nfs boot time y2038 safe
2016-06-20 0:26 [PATCH v2 00/24] Delete CURRENT_TIME and CURRENT_TIME_SEC macros Deepa Dinamani
@ 2016-06-20 0:27 ` Deepa Dinamani
2016-06-20 18:03 ` [PATCH v2 00/24] Delete CURRENT_TIME and CURRENT_TIME_SEC macros Linus Torvalds
2016-06-22 15:49 ` Arnd Bergmann
2 siblings, 0 replies; 6+ messages in thread
From: Deepa Dinamani @ 2016-06-20 0:27 UTC (permalink / raw)
To: linux-fsdevel, linux-kernel
Cc: arnd, tglx, torvalds, tytso, viro, y2038, Trond Myklebust,
Anna Schumaker, linux-nfs
boot_time is represented as a struct timespec.
struct timespec and CURRENT_TIME are not y2038 safe.
Overall, the plan is to use timespec64 and ktime_t for
all internal kernel representation of timestamps.
CURRENT_TIME will also be removed.
boot_time is used to construct the nfs client boot verifier.
Use ktime_t to represent boot_time and ktime_get_real() for
the boot_time value.
Following Trond's request https://lkml.org/lkml/2016/6/9/22 ,
use ktime_t instead of converting to struct timespec64.
Use higher and lower 32 bit parts of ktime_t for the boot
verifier.
Use the lower 32 bit part of ktime_t for the authsys_parms
stamp field.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: Anna Schumaker <anna.schumaker@netapp.com>
Cc: linux-nfs@vger.kernel.org
---
Changes from V1:
* Use ktime_t instead of timespec64_t
* Change algorithm to use boot_time accordingly
fs/nfs/client.c | 2 +-
fs/nfs/netns.h | 2 +-
fs/nfs/nfs4proc.c | 10 ++++++----
fs/nfs/nfs4xdr.c | 2 +-
4 files changed, 9 insertions(+), 7 deletions(-)
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index 0c96528..d1aff29 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1080,7 +1080,7 @@ void nfs_clients_init(struct net *net)
idr_init(&nn->cb_ident_idr);
#endif
spin_lock_init(&nn->nfs_client_lock);
- nn->boot_time = CURRENT_TIME;
+ nn->boot_time = ktime_get_real();
}
#ifdef CONFIG_PROC_FS
diff --git a/fs/nfs/netns.h b/fs/nfs/netns.h
index f0e06e4..fbce0d8 100644
--- a/fs/nfs/netns.h
+++ b/fs/nfs/netns.h
@@ -29,7 +29,7 @@ struct nfs_net {
int cb_users[NFS4_MAX_MINOR_VERSION + 1];
#endif
spinlock_t nfs_client_lock;
- struct timespec boot_time;
+ ktime_t boot_time;
#ifdef CONFIG_PROC_FS
struct proc_dir_entry *proc_nfsfs;
#endif
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 406dd3e..8d9b5a9 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -5062,12 +5062,14 @@ static void nfs4_init_boot_verifier(const struct nfs_client *clp,
if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
/* An impossible timestamp guarantees this value
* will never match a generated boot time. */
- verf[0] = 0;
- verf[1] = cpu_to_be32(NSEC_PER_SEC + 1);
+ verf[0] = cpu_to_be32(U32_MAX);
+ verf[1] = cpu_to_be32(U32_MAX);
} else {
struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
- verf[0] = cpu_to_be32(nn->boot_time.tv_sec);
- verf[1] = cpu_to_be32(nn->boot_time.tv_nsec);
+ u64 ns = ktime_to_ns(nn->boot_time);
+
+ verf[0] = cpu_to_be32(ns >> 32);
+ verf[1] = cpu_to_be32(ns);
}
memcpy(bootverf->data, verf, sizeof(bootverf->data));
}
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index 661e753..5944be0 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -1850,7 +1850,7 @@ static void encode_create_session(struct xdr_stream *xdr,
*p++ = cpu_to_be32(RPC_AUTH_UNIX); /* auth_sys */
/* authsys_parms rfc1831 */
- *p++ = cpu_to_be32(nn->boot_time.tv_nsec); /* stamp */
+ *p++ = cpu_to_be32(ktime_to_ns(nn->boot_time)); /* stamp */
p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
*p++ = cpu_to_be32(0); /* UID */
*p++ = cpu_to_be32(0); /* GID */
--
1.9.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2 00/24] Delete CURRENT_TIME and CURRENT_TIME_SEC macros
2016-06-20 0:26 [PATCH v2 00/24] Delete CURRENT_TIME and CURRENT_TIME_SEC macros Deepa Dinamani
2016-06-20 0:27 ` [PATCH v2 18/24] fs: nfs: Make nfs boot time y2038 safe Deepa Dinamani
@ 2016-06-20 18:03 ` Linus Torvalds
2016-06-20 18:58 ` Deepa Dinamani
2016-06-21 15:00 ` [Y2038] " Arnd Bergmann
2016-06-22 15:49 ` Arnd Bergmann
2 siblings, 2 replies; 6+ messages in thread
From: Linus Torvalds @ 2016-06-20 18:03 UTC (permalink / raw)
To: Deepa Dinamani
Cc: linux-fsdevel, Linux Kernel Mailing List, Arnd Bergmann,
Thomas Gleixner, Theodore Ts'o, Al Viro, y2038,
adilger.kernel@dilger.ca, Adrian Hunter, Anna Schumaker, buchino,
ceph-devel, Chris Mason, Changman Lee, Artem Bityutskiy,
David Sterba, Alex Elder, Eric Paris, Greg Kroah-Hartman,
hiralpat, Ilya Dryomov, Jan Kara, Jaegeuk Kim, Josef Bacik, jejb,
jfs-discussion, Joel Becker, John Stultz, linux-audit,
linux-btrfs, linux-ext4@vger.kernel.org,
Linux F2FS DEV, Mailing List, linux-mtd, Linux NFS Mailing List,
Linux SCSI List, lustre-devel, Martin K. Petersen, Mark Fasheh,
ocfs2-devel, Paul Moore, Sage Weil, Steve French, Dave Kleikamp,
sramars, Trond Myklebust, Yan, Zheng
On Sun, Jun 19, 2016 at 5:26 PM, Deepa Dinamani <deepa.kernel@gmail.com> wrote:
> The series is aimed at getting rid of CURRENT_TIME and CURRENT_TIME_SEC macros.
This version now looks ok to me.
I do have a comment (or maybe just a RFD) for future work.
It does strike me that once we actually change over the inode times to
use timespec64, the calling conventions are going to be fairly
horrendous on most 32-bit architectures.
Gcc handles 8-byte structure returns (on most architectures) by
returning them as two 32-bit registers (%edx:%eax on x86). But once it
is timespec64, that will no longer be the case, and the calling
convention will end up using a pointer to the local stack instead.
So for 32-bit code generation, we *may* want to introduce a new model of doing
set_inode_time(inode, ATTR_ATIME | ATTR_MTIME);
which basically just does
inode->i_atime = inode->i_mtime = current_time(inode);
but with a much easier calling convention on 32-bit architectures.
But that is entirely orthogonal to this patch-set, and should be seen
as a separate issue.
And maybe it doesn't end up helping anyway, but I do think those
"simple" direct assignments will really generate pretty disgusting
code on 32-bit architectures.
That whole
inode->i_atime = inode->i_mtime = CURRENT_TIME;
model really made a lot more sense back in the ancient days when inode
times were just simply 32-bit seconds (not even timeval structures).
Linus
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2 00/24] Delete CURRENT_TIME and CURRENT_TIME_SEC macros
2016-06-20 18:03 ` [PATCH v2 00/24] Delete CURRENT_TIME and CURRENT_TIME_SEC macros Linus Torvalds
@ 2016-06-20 18:58 ` Deepa Dinamani
2016-06-21 15:00 ` [Y2038] " Arnd Bergmann
1 sibling, 0 replies; 6+ messages in thread
From: Deepa Dinamani @ 2016-06-20 18:58 UTC (permalink / raw)
To: Linus Torvalds
Cc: linux-fsdevel, Linux Kernel Mailing List, Arnd Bergmann,
Thomas Gleixner, Theodore Ts'o, Al Viro, y2038 Mailman List,
adilger.kernel@dilger.ca, Adrian Hunter, Anna Schumaker,
Brian Uchino, ceph-devel, Chris Mason, Changman Lee,
Artem Bityutskiy, David Sterba, Alex Elder, Eric Paris,
Greg Kroah-Hartman, Hiral Patel, Ilya Dryomov, Jan Kara,
Jaegeuk Kim, Josef Bacik, James E.J. Bottomley, jfs-discussion,
Joel Becker, John Stultz, linux-audit, linux-btrfs,
linux-ext4@vger.kernel.org, Linux F2FS DEV, Mailing List,
linux-mtd, Linux NFS Mailing List, Linux SCSI List, lustre-devel,
Martin K. Petersen, Mark Fasheh, ocfs2-devel, Paul Moore,
Sage Weil, Steve French, Dave Kleikamp, Suma Ramars,
Trond Myklebust, Yan, Zheng
> This version now looks ok to me.
>
> I do have a comment (or maybe just a RFD) for future work.
>
> It does strike me that once we actually change over the inode times to
> use timespec64, the calling conventions are going to be fairly
> horrendous on most 32-bit architectures.
>
> Gcc handles 8-byte structure returns (on most architectures) by
> returning them as two 32-bit registers (%edx:%eax on x86). But once it
> is timespec64, that will no longer be the case, and the calling
> convention will end up using a pointer to the local stack instead.
>
> So for 32-bit code generation, we *may* want to introduce a new model of doing
>
> set_inode_time(inode, ATTR_ATIME | ATTR_MTIME);
>
> which basically just does
>
> inode->i_atime = inode->i_mtime = current_time(inode);
>
> but with a much easier calling convention on 32-bit architectures.
Arnd and I had discussed something like this before.
But, for entirely different reasons:
Having the set_inode_time() like you suggest will also help switching
of vfs inode times to timespec64.
We were suggesting all the accesses to inode time be abstracted
through something like inode_set_time().
Arnd also had suggested a split representation of fields in the struct
inode as well which led to space savings
as well. And, having the split representation also meant no more
direct assignments:
https://lkml.org/lkml/2016/1/7/20
This in general will be similar to setattr_copy(), but only sets times
rather than other attributes as well.
If this is what is preferred, then the patches to change vfs to use
timespec64 could make use of this and will
need to be refactored. So maybe it would be good to discuss before I
post those patches.
-Deepa
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Y2038] [PATCH v2 00/24] Delete CURRENT_TIME and CURRENT_TIME_SEC macros
2016-06-20 18:03 ` [PATCH v2 00/24] Delete CURRENT_TIME and CURRENT_TIME_SEC macros Linus Torvalds
2016-06-20 18:58 ` Deepa Dinamani
@ 2016-06-21 15:00 ` Arnd Bergmann
1 sibling, 0 replies; 6+ messages in thread
From: Arnd Bergmann @ 2016-06-21 15:00 UTC (permalink / raw)
To: y2038
Cc: Linus Torvalds, Deepa Dinamani, Dave Kleikamp, jfs-discussion,
Trond Myklebust, Adrian Hunter, Chris Mason,
adilger.kernel@dilger.ca, buchino, Thomas Gleixner, Yan, Zheng,
jejb, Paul Moore, Linux SCSI List, Ilya Dryomov,
linux-ext4@vger.kernel.org, Changman Lee, Mark Fasheh, sramars,
John Stultz, Al Viro, David Sterba, Jaegeuk Kim, ceph-devel,
Linux NFS Mailing List, Alex Elder, Theodore Ts'o, Sage Weil,
Martin K. Petersen, Artem Bityutskiy, Josef Bacik,
Greg Kroah-Hartman, hiralpat, Linux Kernel Mailing List,
Eric Paris, Linux F2FS DEV, Mailing List, Steve French,
linux-audit, ocfs2-devel, Jan Kara, linux-fsdevel, linux-mtd,
lustre-devel, Anna Schumaker, linux-btrfs, Joel Becker
On Monday, June 20, 2016 11:03:01 AM CEST you wrote:
> On Sun, Jun 19, 2016 at 5:26 PM, Deepa Dinamani <deepa.kernel@gmail.com> wrote:
> > The series is aimed at getting rid of CURRENT_TIME and CURRENT_TIME_SEC macros.
> Gcc handles 8-byte structure returns (on most architectures) by
> returning them as two 32-bit registers (%edx:%eax on x86). But once it
> is timespec64, that will no longer be the case, and the calling
> convention will end up using a pointer to the local stack instead.
I guess we already have that today, as the implementation of
current_fs_time() is
static inline struct timespec64 tk_xtime(struct timekeeper *tk)
{
struct timespec64 ts;
ts.tv_sec = tk->xtime_sec;
ts.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
return ts;
}
extern struct timespec64 current_kernel_time64(void);
struct timespec64 current_kernel_time64(void)
{
struct timekeeper *tk = &tk_core.timekeeper;
struct timespec64 now;
unsigned long seq;
do {
seq = read_seqcount_begin(&tk_core.seq);
now = tk_xtime(tk);
} while (read_seqcount_retry(&tk_core.seq, seq));
return now;
}
static inline struct timespec current_kernel_time(void)
{
struct timespec64 now = current_kernel_time64();
return timespec64_to_timespec(now);
}
extern struct timespec current_fs_time(struct super_block *sb);
struct timespec current_fs_time(struct super_block *sb)
{
struct timespec now = current_kernel_time();
return timespec_trunc(now, sb->s_time_gran);
}
We can surely do a little better than this, independent of the
conversion in Deepa's patch set.
> So for 32-bit code generation, we *may* want to introduce a new model of doing
>
> set_inode_time(inode, ATTR_ATIME | ATTR_MTIME);
>
> which basically just does
>
> inode->i_atime = inode->i_mtime = current_time(inode);
>
> but with a much easier calling convention on 32-bit architectures.
>
> But that is entirely orthogonal to this patch-set, and should be seen
> as a separate issue.
I've played around with that, but found it hard to avoid going
through memory other than going all the way to the tk_xtime()
access to copy both tk->xtime_sec and the nanoseconds into
the inode fields.
Without that, the set_inode_time() implementation ends up
being more expensive than
inode->i_atime = inode->i_ctime = inode->i_mtime = current_time(inode);
because we still copy through the stack but also have
a couple of conditional branches that we don't have at the
moment.
At the moment, the triple assignment becomes (here on ARM)
c: 4668 mov r0, sp
12: f7ff fffe bl 0 <current_kernel_time64>
3e: f107 0520 add.w r5, r7, #32
12: R_ARM_THM_CALL current_kernel_time64
16: f106 0410 add.w r4, r6, #16
1a: e89d 000f ldmia.w sp, {r0, r1, r2, r3} # load from stack
1e: e885 000f stmia.w r5, {r0, r1, r2, r3} # store into i_atime
22: e884 000f stmia.w r4, {r0, r1, r2, r3} # i_ctime
26: e886 000f stmia.w r6, {r0, r1, r2, r3} # i_mtime
and a slightly more verbose version of the same thing on x86
(storing only 12 bytes instead of 16 is cheaper there, while
ARM does a store-multiple to copy the entire structure).
Arnd
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [Y2038] [PATCH v2 00/24] Delete CURRENT_TIME and CURRENT_TIME_SEC macros
2016-06-20 0:26 [PATCH v2 00/24] Delete CURRENT_TIME and CURRENT_TIME_SEC macros Deepa Dinamani
2016-06-20 0:27 ` [PATCH v2 18/24] fs: nfs: Make nfs boot time y2038 safe Deepa Dinamani
2016-06-20 18:03 ` [PATCH v2 00/24] Delete CURRENT_TIME and CURRENT_TIME_SEC macros Linus Torvalds
@ 2016-06-22 15:49 ` Arnd Bergmann
2 siblings, 0 replies; 6+ messages in thread
From: Arnd Bergmann @ 2016-06-22 15:49 UTC (permalink / raw)
To: y2038, tglx, linux-ext4, jbacik
Cc: Deepa Dinamani, linux-fsdevel, linux-kernel, shaggy,
jfs-discussion, trond.myklebust, clm, adilger.kernel, zyan, jejb,
paul, linux-scsi, cm224.lee, mfasheh, sramars, john.stultz, viro,
dsterba, jaegeuk, ceph-devel, linux-nfs, elder, tytso, sage,
martin.petersen, gregkh, hiralpat, adrian.hunter, eparis,
linux-f2fs-devel, sfrench, linux-audit, ocfs2-devel, jack,
linux-mtd, lustre-devel, torvalds, anna.schumaker, linux-btrfs,
jlbec
On Sunday, June 19, 2016 5:26:59 PM CEST Deepa Dinamani wrote:
> The series is aimed at getting rid of CURRENT_TIME and CURRENT_TIME_SEC macros.
> The macros are not y2038 safe. There is no plan to transition them into being
> y2038 safe.
> ktime_get_* api's can be used in their place. And, these are y2038 safe.
>
> Thanks to Arnd Bergmann for all the guidance and discussions.
>
> Patches 2-4 were mostly generated using coccinelle scripts.
>
> All filesystem timestamps use current_fs_time() for right granularity as
> mentioned in the respective commit texts of patches. This has a changed
> signature, renamed to current_time() and moved to the fs/inode.c.
>
> This series also serves as a preparatory series to transition vfs to 64 bit
> timestamps as outlined here: https://lkml.org/lkml/2016/2/12/104 .
>
> As per Linus's suggestion in https://lkml.org/lkml/2016/5/24/663 , all the
> inode timestamp changes have been squashed into a single patch. Also,
> current_time() now is used as a single generic vfs filesystem timestamp api.
> It also takes struct inode* as argument instead of struct super_block*.
> Posting all patches together in a bigger series so that the big picture is
> clear.
>
> As per the suggestion in https://lwn.net/Articles/672598/, CURRENT_TIME macro
> bug fixes are being handled in a series separate from transitioning vfs to use.
I've looked in detail at all the patches in this version now, and while
overall everything is fine, I found that two patches cannot be part of the
series because of the dependency on the patch that John already took (adding
time64_to_tm), but I think that's ok because we just need to change over
all the users of CURRENT_TIME and CURRENT_TIME_SEC that assign to inode
timestamps in order to prepare for the type change, the other ones
can be changed later.
I also found a few things that could be done differently to make the
later conversion slightly easier, but it's also possible that I missed
part of your bigger plan for those files, and none of them seem important.
Arnd
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2016-06-22 15:51 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2016-06-20 0:26 [PATCH v2 00/24] Delete CURRENT_TIME and CURRENT_TIME_SEC macros Deepa Dinamani
2016-06-20 0:27 ` [PATCH v2 18/24] fs: nfs: Make nfs boot time y2038 safe Deepa Dinamani
2016-06-20 18:03 ` [PATCH v2 00/24] Delete CURRENT_TIME and CURRENT_TIME_SEC macros Linus Torvalds
2016-06-20 18:58 ` Deepa Dinamani
2016-06-21 15:00 ` [Y2038] " Arnd Bergmann
2016-06-22 15:49 ` Arnd Bergmann
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