LU-16896 flr: resync should not change file size

mirror resync could punch a hole reaching the end of file in a
mirror, which could change the file size when the mirror is referred.

This patch calls truncate after punch in this case to keep the file
size unchanged in the mirror.

Lustre-change: https://review.whamcloud.com/51344
Lustre-commit: b9ce342ee196af48d2d25e2811121fe4471f5fd2

Also pick up commit 4cd4bfba473fb370767e1f2014d9fe1531889f82
("LU-16813 utils: move mirror_end initialization) to move
initialization for mirror_end variable in llapi_mirror_resync_many(),
otherwise lfs mirror resync may fail since mirror_end gets reset on
each pass of the loop.

Lustre-change: https://review.whamcloud.com/50919
Lustre-commit: 4cd4bfba473fb370767e1f2014d9fe1531889f82

Signed-off-by: Bobi Jam <bobijam@whamcloud.com>
Change-Id: Ia0fc1f220a32a60f3516c69e86867796ae5c35c7
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/52061
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>

diff --git a/lustre/utils/liblustreapi_layout.c b/lustre/utils/liblustreapi_layout.c
index 68c9537..d907fbb 100644 (file)
--- a/lustre/utils/liblustreapi_layout.c
+++ b/lustre/utils/liblustreapi_layout.c
@@ -3386,6 +3386,7 @@ int llapi_mirror_resync_many_params(int fd, struct llapi_layout *layout,
        void *buf;
        uint64_t pos = start;
        uint64_t data_off = pos, data_end = pos;
+       uint64_t mirror_end = LUSTRE_EOF;
        uint32_t src = 0;
        int i;
        int rc;
@@ -3414,14 +3415,13 @@ int llapi_mirror_resync_many_params(int fd, struct llapi_layout *layout,
        now = last_bw_print = start_time;
 
        while (pos < end) {
-               uint64_t mirror_end;
                ssize_t bytes_read;
                size_t to_read;
                size_t to_write;
+               size_t data_size;
 
                if (pos >= data_end) {
                        off_t tmp_off;
-                       size_t data_size;
 
                        if (pos >= mirror_end || !src) {
                                rc = llapi_mirror_find(layout, pos, end,
@@ -3479,15 +3479,14 @@ int llapi_mirror_resync_many_params(int fd, struct llapi_layout *layout,
                                         */
                                        rc = llapi_mirror_truncate(fd, mid,
                                                                   cur_pos);
-                               else
+                               else if (to_punch)
                                        rc = llapi_mirror_punch(fd, mid,
                                                        cur_pos, to_punch);
                                /**
-                                * hole at the end of file, so just
-                                * truncate up to set size.
+                                * hole at the end of file, so just truncate up
+                                * to set size.
                                 */
-                               if (!rc && data_off == data_end &&
-                                   data_end == stbuf.st_size)
+                               if (!rc && data_off == data_end && !data_size)
                                        rc = llapi_mirror_truncate(fd,
                                                                mid, data_end);