* Issue fsync recursively on PGDATA and all its contents. * * We fsync regular files and directories wherever they are, but we follow * symlinks only for pg_wal (or pg_xlog) and immediately under pg_tblspc. * Other symlinks are presumed to point at files we're not responsible for * fsyncing, and might not have privileges to write at all. * * serverVersion indicates the version of the server
| 61 | * serverVersion indicates the version of the server to be fsync'd. |
| 62 | */ |
| 63 | void |
| 64 | fsync_pgdata(const char *pg_data, |
| 65 | int serverVersion) |
| 66 | { |
| 67 | bool xlog_is_symlink; |
| 68 | char pg_wal[MAXPGPATH]; |
| 69 | char pg_tblspc[MAXPGPATH]; |
| 70 | |
| 71 | /* handle renaming of pg_xlog to pg_wal in post-10 clusters */ |
| 72 | snprintf(pg_wal, MAXPGPATH, "%s/%s", pg_data, |
| 73 | serverVersion < MINIMUM_VERSION_FOR_PG_WAL ? "pg_xlog" : "pg_wal"); |
| 74 | snprintf(pg_tblspc, MAXPGPATH, "%s/pg_tblspc", pg_data); |
| 75 | |
| 76 | /* |
| 77 | * If pg_wal is a symlink, we'll need to recurse into it separately, |
| 78 | * because the first walkdir below will ignore it. |
| 79 | */ |
| 80 | xlog_is_symlink = false; |
| 81 | |
| 82 | #ifndef WIN32 |
| 83 | { |
| 84 | struct stat st; |
| 85 | |
| 86 | if (lstat(pg_wal, &st) < 0) |
| 87 | pg_log_error("could not stat file \"%s\": %m", pg_wal); |
| 88 | else if (S_ISLNK(st.st_mode)) |
| 89 | xlog_is_symlink = true; |
| 90 | } |
| 91 | #else |
| 92 | if (pgwin32_is_junction(pg_wal)) |
| 93 | xlog_is_symlink = true; |
| 94 | #endif |
| 95 | |
| 96 | /* |
| 97 | * If possible, hint to the kernel that we're soon going to fsync the data |
| 98 | * directory and its contents. |
| 99 | */ |
| 100 | #ifdef PG_FLUSH_DATA_WORKS |
| 101 | walkdir(pg_data, pre_sync_fname, false); |
| 102 | if (xlog_is_symlink) |
| 103 | walkdir(pg_wal, pre_sync_fname, false); |
| 104 | walkdir(pg_tblspc, pre_sync_fname, true); |
| 105 | #endif |
| 106 | |
| 107 | /* |
| 108 | * Now we do the fsync()s in the same order. |
| 109 | * |
| 110 | * The main call ignores symlinks, so in addition to specially processing |
| 111 | * pg_wal if it's a symlink, pg_tblspc has to be visited separately with |
| 112 | * process_symlinks = true. Note that if there are any plain directories |
| 113 | * in pg_tblspc, they'll get fsync'd twice. That's not an expected case |
| 114 | * so we don't worry about optimizing it. |
| 115 | */ |
| 116 | walkdir(pg_data, fsync_fname, false); |
| 117 | if (xlog_is_symlink) |
| 118 | walkdir(pg_wal, fsync_fname, false); |
| 119 | walkdir(pg_tblspc, fsync_fname, true); |
| 120 | } |
no test coverage detected