LU-13397 lfs: mirror extend/copy keeps sparseness

[fs/lustre-release.git] / lustre / utils / lfs.c

diff --git a/lustre/utils/lfs.c b/lustre/utils/lfs.c
index 1f9cd61..42a26ab 100644 (file)
--- a/lustre/utils/lfs.c
+++ b/lustre/utils/lfs.c
@@ -925,14 +925,13 @@ out:
 static int migrate_copy_data(int fd_src, int fd_dst, int (*check_file)(int))
 {
        struct llapi_layout *layout;
-       size_t   buf_size = 4 * 1024 * 1024;
-       void    *buf = NULL;
-       ssize_t  rsize = -1;
-       ssize_t  wsize = 0;
-       size_t   rpos = 0;
-       size_t   wpos = 0;
-       off_t    bufoff = 0;
-       int      rc;
+       size_t buf_size = 4 * 1024 * 1024;
+       void *buf = NULL;
+       off_t pos = 0;
+       off_t data_end = 0;
+       size_t page_size = sysconf(_SC_PAGESIZE);
+       bool sparse;
+       int rc;
 
        layout = llapi_layout_get_by_fd(fd_src, 0);
        if (layout) {
@@ -946,43 +945,76 @@ static int migrate_copy_data(int fd_src, int fd_dst, int (*check_file)(int))
        }
 
        /* Use a page-aligned buffer for direct I/O */
-       rc = posix_memalign(&buf, getpagesize(), buf_size);
+       rc = posix_memalign(&buf, page_size, buf_size);
        if (rc != 0)
                return -rc;
 
+       sparse = llapi_file_is_sparse(fd_src);
+       if (sparse) {
+               rc = ftruncate(fd_dst, pos);
+               if (rc < 0) {
+                       rc = -errno;
+                       return rc;
+               }
+       }
+
        while (1) {
-               /*
-                * read new data only if we have written all
-                * previously read data
-                */
-               if (wpos == rpos) {
-                       if (check_file) {
-                               rc = check_file(fd_src);
+               off_t data_off;
+               size_t to_read, to_write;
+               ssize_t rsize;
+
+               if (sparse && pos >= data_end) {
+                       size_t data_size;
+
+                       data_off = llapi_data_seek(fd_src, pos, &data_size);
+                       if (data_off < 0) {
+                               /* Non-fatal, switch to full copy */
+                               sparse = false;
+                               continue;
+                       }
+                       /* hole at the end of file, truncate up to it */
+                       if (!data_size) {
+                               rc = ftruncate(fd_dst, data_off);
                                if (rc < 0)
                                        goto out;
                        }
+                       pos = data_off & ~(page_size - 1);
+                       data_end = data_off + data_size;
+                       to_read = ((data_end - pos - 1) | (page_size - 1)) + 1;
+                       to_read = MIN(to_read, buf_size);
+               } else {
+                       to_read = buf_size;
+               }
 
-                       rsize = read(fd_src, buf, buf_size);
-                       if (rsize < 0) {
-                               rc = -errno;
+               if (check_file) {
+                       rc = check_file(fd_src);
+                       if (rc < 0)
                                goto out;
-                       }
-
-                       rpos += rsize;
-                       bufoff = 0;
                }
 
-               /* eof ? */
+               rsize = pread(fd_src, buf, to_read, pos);
+               if (rsize < 0) {
+                       rc = -errno;
+                       goto out;
+               }
+               /* EOF */
                if (rsize == 0)
                        break;
 
-               wsize = write(fd_dst, buf + bufoff, rpos - wpos);
-               if (wsize < 0) {
-                       rc = -errno;
-                       break;
+               to_write = rsize;
+               while (to_write > 0) {
+                       ssize_t written;
+
+                       written = pwrite(fd_dst, buf, to_write, pos);
+                       if (written < 0) {
+                               rc = -errno;
+                               goto out;
+                       }
+                       pos += written;
+                       to_write -= written;
                }
-               wpos += wsize;
-               bufoff += wsize;
+               if (rc || rsize < to_read)
+                       break;
        }
 
        rc = fsync(fd_dst);