Commit 9b6304c1 authored by Jeff Layton's avatar Jeff Layton Committed by Christian Brauner
Browse files

fs: add ctime accessors infrastructure 



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: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
Signed-off-by: default avatarJeff Layton <jlayton@kernel.org>
Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Message-Id: <20230705185812.579118-2-jlayton@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent bc2390f2

fs/inode.c

+16 −0
Original line number Original line Diff line number Diff line
@@ -2501,6 +2501,22 @@ struct timespec64 current_time(struct inode *inode) 
}

}

EXPORT_SYMBOL(current_time);

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

 * in_group_or_capable - check whether caller is CAP_FSETID privileged

 * @idmap:	idmap of the mount @inode was found from

 * @idmap:	idmap of the mount @inode was found from

include/linux/fs.h

+44 −1
Original line number Original line Diff line number Diff line
@@ -1474,7 +1474,50 @@ static inline bool fsuidgid_has_mapping(struct super_block *sb, 
	       kgid_has_mapping(fs_userns, kgid);

	       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.

 * Snapshotting support.