From: David Disseldorp <ddiss@suse.de>
Date: Thu, 18 Apr 2019 14:15:47 +0200
Subject: ceph: add ceph.snap.btime vxattr
Git-commit: 100cc610a550affcbef13d74855f736b92caa947
Patch-mainline: v5.3-rc1
References: bsc#1148133 bsc#1148570

The ceph.snap.btime virtual xattr provides the snapshot creation (birth)
time in $secs.$nsecs format.

Link: https://tracker.ceph.com/issues/38838
Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Acked-by: Luis Henriques <lhenriques@suse.com>
[luis: modified snprintf format specifier %lld to %ld since i_snap_btime
 has been changed to a struct timespec, instead of timespec64.  This is
 because we're not carrying commit 473bd2d780d1 ("libceph: use timespec64
 in for keepalive2 and ticket validity").]
---
 fs/ceph/xattr.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 2cbb9c239183..5d8a6f7c5869 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -272,6 +272,19 @@ static size_t ceph_vxattrcb_quota_max_fi
 	return snprintf(val, size, "%llu", ci->i_max_files);
 }
 
+/* snapshots */
+static bool ceph_vxattrcb_snap_btime_exists(struct ceph_inode_info *ci)
+{
+	return (ci->i_snap_btime.tv_sec != 0 || ci->i_snap_btime.tv_nsec != 0);
+}
+
+static size_t ceph_vxattrcb_snap_btime(struct ceph_inode_info *ci, char *val,
+				       size_t size)
+{
+	return snprintf(val, size, "%ld.%09ld", ci->i_snap_btime.tv_sec,
+			ci->i_snap_btime.tv_nsec);
+}
+
 #define CEPH_XATTR_NAME(_type, _name)	XATTR_CEPH_PREFIX #_type "." #_name
 #define CEPH_XATTR_NAME2(_type, _name, _name2)	\
 	XATTR_CEPH_PREFIX #_type "." #_name "." #_name2
@@ -340,6 +353,13 @@ static struct ceph_vxattr ceph_dir_vxatt
 	},
 	XATTR_QUOTA_FIELD(quota, max_bytes),
 	XATTR_QUOTA_FIELD(quota, max_files),
+	{
+		.name = "ceph.snap.btime",
+		.name_size = sizeof("ceph.snap.btime"),
+		.getxattr_cb = ceph_vxattrcb_snap_btime,
+		.exists_cb = ceph_vxattrcb_snap_btime_exists,
+		.flags = VXATTR_FLAG_READONLY,
+	},
 	{ .name = NULL, 0 }	/* Required table terminator */
 };
 static size_t ceph_dir_vxattrs_name_size;	/* total size of all names */
@@ -359,6 +379,13 @@ static struct ceph_vxattr ceph_file_vxat
 	XATTR_LAYOUT_FIELD(file, layout, object_size),
 	XATTR_LAYOUT_FIELD(file, layout, pool),
 	XATTR_LAYOUT_FIELD(file, layout, pool_namespace),
+	{
+		.name = "ceph.snap.btime",
+		.name_size = sizeof("ceph.snap.btime"),
+		.getxattr_cb = ceph_vxattrcb_snap_btime,
+		.exists_cb = ceph_vxattrcb_snap_btime_exists,
+		.flags = VXATTR_FLAG_READONLY,
+	},
 	{ .name = NULL, 0 }	/* Required table terminator */
 };
 static size_t ceph_file_vxattrs_name_size;	/* total size of all names */