[PATCH v2 7/7] vfs: remove inode_set_ctime_deleg()

Jeff Layton
2025-07-26T14:32:13Z

Now that nfsd is vetting the timestamps internally, there is no need for
this function. If ATTR_DELEG is set, then skip the multigrain update and
set what was requested.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
fs/attr.c | 19 +++-----------
fs/inode.c | 73 ------------------------------------------------------
include/linux/fs.h | 2 --
3 files changed, 4 insertions(+), 90 deletions(-)

diff --git a/fs/attr.c b/fs/attr.c
index f0dabd2985989d283a931536a5fc53eda366b373..e75f06b760015640bafd596457cd14c746c7e272 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -287,14 +287,7 @@ static void setattr_copy_mgtime(struct inode *inode, const struct iattr *attr)
struct timespec64 now;

if (ia_valid & ATTR_CTIME) {
- /*
- * In the case of an update for a write delegation, we must respect
- * the value in ia_ctime and not use the current time.
- */
- if (ia_valid & ATTR_DELEG)
- now = inode_set_ctime_deleg(inode, attr->ia_ctime);
- else
- now = inode_set_ctime_current(inode);
+ now = inode_set_ctime_current(inode);
} else {
/* If ATTR_CTIME isn't set, then ATTR_MTIME shouldn't be either. */
WARN_ON_ONCE(ia_valid & ATTR_MTIME);
@@ -352,19 +345,15 @@ void setattr_copy(struct mnt_idmap *idmap, struct inode *inode,
inode->i_mode = mode;
}

- if (is_mgtime(inode))
+ if (!(ia_valid & ATTR_DELEG) && is_mgtime(inode))
return setattr_copy_mgtime(inode, attr);

if (ia_valid & ATTR_ATIME)
inode_set_atime_to_ts(inode, attr->ia_atime);
if (ia_valid & ATTR_MTIME)
inode_set_mtime_to_ts(inode, attr->ia_mtime);
- if (ia_valid & ATTR_CTIME) {
- if (ia_valid & ATTR_DELEG)
- inode_set_ctime_deleg(inode, attr->ia_ctime);
- else
- inode_set_ctime_to_ts(inode, attr->ia_ctime);
- }
+ if (ia_valid & ATTR_CTIME)
+ inode_set_ctime_to_ts(inode, attr->ia_ctime);
}
EXPORT_SYMBOL(setattr_copy);

diff --git a/fs/inode.c b/fs/inode.c
index 99318b157a9a13b3dd8dad0f5f90951f08ef64de..f45054fe48b8a0339e60fd2aa17daaad5a7957e7 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -2783,79 +2783,6 @@ struct timespec64 inode_set_ctime_current(struct inode *inode)
}
EXPORT_SYMBOL(inode_set_ctime_current);

-/**
- * inode_set_ctime_deleg - try to update the ctime on a delegated inode
- * @inode: inode to update
- * @update: timespec64 to set the ctime
- *
- * Attempt to atomically update the ctime on behalf of a delegation holder.
- *
- * The nfs server can call back the holder of a delegation to get updated
- * inode attributes, including the mtime. When updating the mtime, update
- * the ctime to a value at least equal to that.
- *
- * This can race with concurrent updates to the inode, in which
- * case the update is skipped.
- *
- * Note that this works even when multigrain timestamps are not enabled,
- * so it is used in either case.
- */
-struct timespec64 inode_set_ctime_deleg(struct inode *inode, struct timespec64 update)
-{
- struct timespec64 now, cur_ts;
- u32 cur, old;
-
- /* pairs with try_cmpxchg below */
- cur = smp_load_acquire(&inode->i_ctime_nsec);
- cur_ts.tv_nsec = cur & ~I_CTIME_QUERIED;
- cur_ts.tv_sec = inode->i_ctime_sec;
-
- /* If the update is older than the existing value, skip it. */
- if (timespec64_compare(&update, &cur_ts) <= 0)
- return cur_ts;
-
- ktime_get_coarse_real_ts64_mg(&now);
-
- /* Clamp the update to "now" if it's in the future */
- if (timespec64_compare(&update, &now) > 0)
- update = now;
-
- update = timestamp_truncate(update, inode);
-
- /* No need to update if the values are already the same */
- if (timespec64_equal(&update, &cur_ts))
- return cur_ts;
-
- /*
- * Try to swap the nsec value into place. If it fails, that means
- * it raced with an update due to a write or similar activity. That
- * stamp takes precedence, so just skip the update.
- */
-retry:
- old = cur;
- if (try_cmpxchg(&inode->i_ctime_nsec, &cur, update.tv_nsec)) {
- inode->i_ctime_sec = update.tv_sec;
- mgtime_counter_inc(mg_ctime_swaps);
- return update;
- }
-
- /*
- * Was the change due to another task marking the old ctime QUERIED?
- *
- * If so, then retry the swap. This can only happen once since
- * the only way to clear I_CTIME_QUERIED is to stamp the inode
- * with a new ctime.
- */
- if (!(old & I_CTIME_QUERIED) && (cur == (old | I_CTIME_QUERIED)))
- goto retry;
-
- /* Otherwise, it was a new timestamp. */
- cur_ts.tv_sec = inode->i_ctime_sec;
- cur_ts.tv_nsec = cur & ~I_CTIME_QUERIED;
- return cur_ts;
-}
-EXPORT_SYMBOL(inode_set_ctime_deleg);
-
/**
* in_group_or_capable - check whether caller is CAP_FSETID privileged
* @idmap: idmap of the mount @inode was found from
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f18f45e88545c39716b917b1378fb7248367b41d..08f2d813dd40b5dd4fe07d9636e94252915d6235 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1657,8 +1657,6 @@ static inline bool fsuidgid_has_mapping(struct super_block *sb,

struct timespec64 current_time(struct inode *inode);
struct timespec64 inode_set_ctime_current(struct inode *inode);
-struct timespec64 inode_set_ctime_deleg(struct inode *inode,
- struct timespec64 update);

static inline time64_t inode_get_atime_sec(const struct inode *inode)
{

--
2.50.1