From 5691e15695694c0947f093316af84f4717cfca46 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Wed, 5 Jul 2023 14:58:10 -0400 Subject: [PATCH] fs: add ctime accessors infrastructure commit 9b6304c1d53745c300b86f202d0dcff395e2d2db upstream. struct timespec64 has unused bits in the tv_nsec field that can be used for other purposes. In future patches, we're going to change how the inode->i_ctime is accessed in certain inodes in order to make use of them. In order to do that safely though, we'll need to eradicate raw accesses of the inode->i_ctime field from the kernel. Add new accessor functions for the ctime that we use to replace them. Reviewed-by: Jan Kara Reviewed-by: Luis Chamberlain Signed-off-by: Jeff Layton Reviewed-by: Damien Le Moal Message-Id: <20230705185812.579118-2-jlayton@kernel.org> Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman --- fs/inode.c | 16 ++++++++++++++++ include/linux/fs.h | 45 ++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 60 insertions(+), 1 deletion(-) diff --git a/fs/inode.c b/fs/inode.c index 6ae760d..73ad1b0 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2502,6 +2502,22 @@ struct timespec64 current_time(struct inode *inode) EXPORT_SYMBOL(current_time); /** + * inode_set_ctime_current - set the ctime to current_time + * @inode: inode + * + * Set the inode->i_ctime to the current value for the inode. Returns + * the current value that was assigned to i_ctime. + */ +struct timespec64 inode_set_ctime_current(struct inode *inode) +{ + struct timespec64 now = current_time(inode); + + inode_set_ctime(inode, now.tv_sec, now.tv_nsec); + return now; +} +EXPORT_SYMBOL(inode_set_ctime_current); + +/** * in_group_or_capable - check whether caller is CAP_FSETID privileged * @mnt_userns: user namespace of the mount @inode was found from * @inode: inode to check diff --git a/include/linux/fs.h b/include/linux/fs.h index dc74531..b6af6ab 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1812,7 +1812,50 @@ static inline bool fsuidgid_has_mapping(struct super_block *sb, kgid_has_mapping(fs_userns, kgid); } -extern struct timespec64 current_time(struct inode *inode); +struct timespec64 current_time(struct inode *inode); +struct timespec64 inode_set_ctime_current(struct inode *inode); + +/** + * inode_get_ctime - fetch the current ctime from the inode + * @inode: inode from which to fetch ctime + * + * Grab the current ctime from the inode and return it. + */ +static inline struct timespec64 inode_get_ctime(const struct inode *inode) +{ + return inode->i_ctime; +} + +/** + * inode_set_ctime_to_ts - set the ctime in the inode + * @inode: inode in which to set the ctime + * @ts: value to set in the ctime field + * + * Set the ctime in @inode to @ts + */ +static inline struct timespec64 inode_set_ctime_to_ts(struct inode *inode, + struct timespec64 ts) +{ + inode->i_ctime = ts; + return ts; +} + +/** + * inode_set_ctime - set the ctime in the inode + * @inode: inode in which to set the ctime + * @sec: tv_sec value to set + * @nsec: tv_nsec value to set + * + * Set the ctime in @inode to { @sec, @nsec } + */ +static inline struct timespec64 inode_set_ctime(struct inode *inode, + time64_t sec, long nsec) +{ + struct timespec64 ts = { .tv_sec = sec, + .tv_nsec = nsec }; + + return inode_set_ctime_to_ts(inode, ts); +} /* * Snapshotting support. -- 2.7.4