+/**
+ * Internal helper for migrate_copy_data(). Check lease and report error if
+ * need be.
+ *
+ * \param[in] fd File descriptor on which to check the lease.
+ * \param[out] lease_broken Set to true if the lease was broken.
+ * \param[in] group_locked Whether a group lock was taken or not.
+ * \param[in] path Name of the file being processed, for error
+ * reporting
+ *
+ * \retval 0 Migration can keep on going.
+ * \retval -errno Error occurred, abort migration.
+ */
+static int check_lease(int fd, bool *lease_broken, bool group_locked,
+ const char *path)
+{
+ int rc;
+
+ if (!file_lease_supported)
+ return 0;
+
+ rc = llapi_lease_check(fd);
+ if (rc > 0)
+ return 0; /* llapi_check_lease returns > 0 on success. */
+
+ if (!group_locked) {
+ fprintf(stderr, "%s: cannot migrate '%s': file busy\n",
+ progname, path);
+ rc = rc ? rc : -EAGAIN;
+ } else {
+ fprintf(stderr, "%s: external attempt to access file '%s' "
+ "blocked until migration ends.\n", progname, path);
+ rc = 0;
+ }
+ *lease_broken = true;
+ return rc;
+}
+
+static int migrate_copy_data(int fd_src, int fd_dst, size_t buf_size,
+ bool group_locked, const char *fname)
+{
+ 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;
+ bool lease_broken = false;
+
+ /* Use a page-aligned buffer for direct I/O */
+ rc = posix_memalign(&buf, getpagesize(), buf_size);
+ if (rc != 0)
+ return -rc;
+
+ while (1) {
+ /* read new data only if we have written all
+ * previously read data */
+ if (wpos == rpos) {
+ if (!lease_broken) {
+ rc = check_lease(fd_src, &lease_broken,
+ group_locked, fname);
+ if (rc < 0)
+ goto out;
+ }
+ rsize = read(fd_src, buf, buf_size);
+ if (rsize < 0) {
+ rc = -errno;
+ fprintf(stderr, "%s: %s: read failed: %s\n",
+ progname, fname, strerror(-rc));
+ goto out;
+ }
+ rpos += rsize;
+ bufoff = 0;
+ }
+ /* eof ? */
+ if (rsize == 0)
+ break;
+
+ wsize = write(fd_dst, buf + bufoff, rpos - wpos);
+ if (wsize < 0) {
+ rc = -errno;
+ fprintf(stderr,
+ "%s: %s: write failed on volatile: %s\n",
+ progname, fname, strerror(-rc));
+ goto out;
+ }
+ wpos += wsize;
+ bufoff += wsize;
+ }
+
+ rc = fsync(fd_dst);
+ if (rc < 0) {
+ rc = -errno;
+ fprintf(stderr, "%s: %s: fsync failed: %s\n",
+ progname, fname, strerror(-rc));
+ }
+
+out:
+ free(buf);
+ return rc;
+}
+
+static int migrate_copy_timestamps(int fdv, const struct stat *st)
+{
+ struct timeval tv[2] = {
+ {.tv_sec = st->st_atime},
+ {.tv_sec = st->st_mtime}
+ };
+
+ return futimes(fdv, tv);
+}
+
+static int migrate_block(int fd, int fdv, const struct stat *st,
+ size_t buf_size, const char *name)
+{
+ __u64 dv1;
+ int gid;
+ int rc;
+ int rc2;
+
+ rc = llapi_get_data_version(fd, &dv1, LL_DV_RD_FLUSH);
+ if (rc < 0) {
+ fprintf(stderr, "%s: %s: cannot get dataversion: %s\n",
+ progname, name, strerror(-rc));
+ return rc;
+ }
+
+ do
+ gid = random();
+ while (gid == 0);
+
+ /* The grouplock blocks all concurrent accesses to the file.
+ * It has to be taken after llapi_get_data_version as it would
+ * block it too. */
+ rc = llapi_group_lock(fd, gid);
+ if (rc < 0) {
+ fprintf(stderr, "%s: %s: cannot get group lock: %s\n",
+ progname, name, strerror(-rc));
+ return rc;
+ }
+
+ rc = migrate_copy_data(fd, fdv, buf_size, true, name);
+ if (rc < 0) {
+ fprintf(stderr, "%s: %s: data copy failed\n", progname, name);
+ goto out_unlock;
+ }
+
+ /* Make sure we keep original atime/mtime values */
+ rc = migrate_copy_timestamps(fdv, st);
+ if (rc < 0) {
+ fprintf(stderr, "%s: %s: timestamp copy failed\n",
+ progname, name);
+ goto out_unlock;
+ }
+
+ /* swap layouts
+ * for a migration we need to check data version on file did
+ * not change.
+ *
+ * Pass in gid=0 since we already own grouplock. */
+ rc = llapi_fswap_layouts_grouplock(fd, fdv, dv1, 0, 0,
+ SWAP_LAYOUTS_CHECK_DV1);
+ if (rc == -EAGAIN) {
+ fprintf(stderr, "%s: %s: dataversion changed during copy, "
+ "migration aborted\n", progname, name);
+ goto out_unlock;
+ } else if (rc < 0) {
+ fprintf(stderr, "%s: %s: cannot swap layouts: %s\n", progname,
+ name, strerror(-rc));
+ goto out_unlock;
+ }
+
+out_unlock:
+ rc2 = llapi_group_unlock(fd, gid);
+ if (rc2 < 0 && rc == 0) {
+ fprintf(stderr, "%s: %s: putting group lock failed: %s\n",
+ progname, name, strerror(-rc2));
+ rc = rc2;
+ }
+
+ return rc;
+}
+
+static int migrate_nonblock(int fd, int fdv, const struct stat *st,
+ size_t buf_size, const char *name)
+{
+ __u64 dv1;
+ __u64 dv2;
+ int rc;
+
+ rc = llapi_get_data_version(fd, &dv1, LL_DV_RD_FLUSH);
+ if (rc < 0) {
+ fprintf(stderr, "%s: %s: cannot get data version: %s\n",
+ progname, name, strerror(-rc));
+ return rc;
+ }
+
+ rc = migrate_copy_data(fd, fdv, buf_size, false, name);
+ if (rc < 0) {
+ fprintf(stderr, "%s: %s: data copy failed\n", progname, name);
+ return rc;
+ }
+
+ rc = llapi_get_data_version(fd, &dv2, LL_DV_RD_FLUSH);
+ if (rc != 0) {
+ fprintf(stderr, "%s: %s: cannot get data version: %s\n",
+ progname, name, strerror(-rc));
+ return rc;
+ }
+
+ if (dv1 != dv2) {
+ rc = -EAGAIN;
+ fprintf(stderr, "%s: %s: data version changed during "
+ "migration\n",
+ progname, name);
+ return rc;
+ }
+
+ /* Make sure we keep original atime/mtime values */
+ rc = migrate_copy_timestamps(fdv, st);
+ if (rc < 0) {
+ fprintf(stderr, "%s: %s: timestamp copy failed\n",
+ progname, name);
+ return rc;
+ }
+
+ /* Atomically put lease, swap layouts and close.
+ * for a migration we need to check data version on file did
+ * not change. */
+ rc = llapi_fswap_layouts(fd, fdv, 0, 0, SWAP_LAYOUTS_CLOSE);
+ if (rc < 0) {
+ fprintf(stderr, "%s: %s: cannot swap layouts: %s\n",
+ progname, name, strerror(-rc));
+ return rc;
+ }
+
+ return 0;
+}
+
git://git.whamcloud.com / fs / lustre-release.git / commitdiff