diff options
Diffstat (limited to 'src/backend/access/transam/xlog.c')
| -rw-r--r-- | src/backend/access/transam/xlog.c | 123 |
1 files changed, 68 insertions, 55 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 9be0cb236d3..6f8810e1490 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -10702,19 +10702,17 @@ issue_xlog_fsync(int fd, XLogSegNo segno) * active at the same time, and they don't conflict with an exclusive backup * either. * - * tablespaces is required only when this function is called while - * the streaming base backup requested by pg_basebackup is running. - * NULL should be specified otherwise. + * labelfile and tblspcmapfile must be passed as NULL when starting an + * exclusive backup, and as initially-empty StringInfos for a non-exclusive + * backup. + * + * If "tablespaces" isn't NULL, it receives a list of tablespaceinfo structs + * describing the cluster's tablespaces. * * tblspcmapfile is required mainly for tar format in windows as native windows * utilities are not able to create symlinks while extracting files from tar. * However for consistency, the same is used for all platforms. * - * needtblspcmapfile is true for the cases (exclusive backup and for - * non-exclusive backup only when tar format is used for taking backup) - * when backup needs to generate tablespace_map file, it is used to - * embed escape character before newline character in tablespace path. - * * Returns the minimum WAL location that must be present to restore from this * backup, and the corresponding timeline ID in *starttli_p. * @@ -10727,7 +10725,7 @@ issue_xlog_fsync(int fd, XLogSegNo segno) XLogRecPtr do_pg_start_backup(const char *backupidstr, bool fast, TimeLineID *starttli_p, StringInfo labelfile, List **tablespaces, - StringInfo tblspcmapfile, bool needtblspcmapfile) + StringInfo tblspcmapfile) { bool exclusive = (labelfile == NULL); bool backup_started_in_recovery = false; @@ -10940,9 +10938,10 @@ do_pg_start_backup(const char *backupidstr, bool fast, TimeLineID *starttli_p, XLogFileName(xlogfilename, starttli, _logSegNo, wal_segment_size); /* - * Construct tablespace_map file + * Construct tablespace_map file. If caller isn't interested in this, + * we make a local StringInfo. */ - if (exclusive) + if (tblspcmapfile == NULL) tblspcmapfile = makeStringInfo(); datadirpathlen = strlen(DataDir); @@ -10955,11 +10954,11 @@ do_pg_start_backup(const char *backupidstr, bool fast, TimeLineID *starttli_p, char linkpath[MAXPGPATH]; char *relpath = NULL; int rllen; - StringInfoData buflinkpath; - char *s = linkpath; + StringInfoData escapedpath; + char *s; - /* Skip special stuff */ - if (strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0) + /* Skip anything that doesn't look like a tablespace */ + if (strspn(de->d_name, "0123456789") != strlen(de->d_name)) continue; snprintf(fullpath, sizeof(fullpath), "pg_tblspc/%s", de->d_name); @@ -10983,18 +10982,15 @@ do_pg_start_backup(const char *backupidstr, bool fast, TimeLineID *starttli_p, linkpath[rllen] = '\0'; /* - * Add the escape character '\\' before newline in a string to - * ensure that we can distinguish between the newline in the - * tablespace path and end of line while reading tablespace_map - * file during archive recovery. + * Build a backslash-escaped version of the link path to include + * in the tablespace map file. */ - initStringInfo(&buflinkpath); - - while (*s) + initStringInfo(&escapedpath); + for (s = linkpath; *s; s++) { - if ((*s == '\n' || *s == '\r') && needtblspcmapfile) - appendStringInfoChar(&buflinkpath, '\\'); - appendStringInfoChar(&buflinkpath, *s++); + if (*s == '\n' || *s == '\r' || *s == '\\') + appendStringInfoChar(&escapedpath, '\\'); + appendStringInfoChar(&escapedpath, *s); } /* @@ -11009,16 +11005,17 @@ do_pg_start_backup(const char *backupidstr, bool fast, TimeLineID *starttli_p, ti = palloc(sizeof(tablespaceinfo)); ti->oid = pstrdup(de->d_name); - ti->path = pstrdup(buflinkpath.data); + ti->path = pstrdup(linkpath); ti->rpath = relpath ? pstrdup(relpath) : NULL; ti->size = -1; if (tablespaces) *tablespaces = lappend(*tablespaces, ti); - appendStringInfo(tblspcmapfile, "%s %s\n", ti->oid, ti->path); + appendStringInfo(tblspcmapfile, "%s %s\n", + ti->oid, escapedpath.data); - pfree(buflinkpath.data); + pfree(escapedpath.data); #else /* @@ -11034,9 +11031,10 @@ do_pg_start_backup(const char *backupidstr, bool fast, TimeLineID *starttli_p, FreeDir(tblspcdir); /* - * Construct backup label file + * Construct backup label file. If caller isn't interested in this, + * we make a local StringInfo. */ - if (exclusive) + if (labelfile == NULL) labelfile = makeStringInfo(); /* Use the log timezone here, not the session timezone */ @@ -11898,22 +11896,20 @@ read_backup_label(XLogRecPtr *checkPointLoc, bool *backupEndRequired, * recovering from a backup dump file, and we therefore need to create symlinks * as per the information present in tablespace_map file. * - * Returns true if a tablespace_map file was found (and fills the link - * information for all the tablespace links present in file); returns false - * if not. + * Returns true if a tablespace_map file was found (and fills *tablespaces + * with a tablespaceinfo struct for each tablespace listed in the file); + * returns false if not. */ static bool read_tablespace_map(List **tablespaces) { tablespaceinfo *ti; FILE *lfp; - char tbsoid[MAXPGPATH]; - char *tbslinkpath; char str[MAXPGPATH]; int ch, - prev_ch = -1, - i = 0, + i, n; + bool was_backslash; /* * See if tablespace_map file is present @@ -11932,38 +11928,55 @@ read_tablespace_map(List **tablespaces) /* * Read and parse the link name and path lines from tablespace_map file * (this code is pretty crude, but we are not expecting any variability in - * the file format). While taking backup we embed escape character '\\' - * before newline in tablespace path, so that during reading of - * tablespace_map file, we could distinguish newline in tablespace path - * and end of line. Now while reading tablespace_map file, remove the - * escape character that has been added in tablespace path during backup. + * the file format). De-escape any backslashes that were inserted. */ + i = 0; + was_backslash = false; while ((ch = fgetc(lfp)) != EOF) { - if ((ch == '\n' || ch == '\r') && prev_ch != '\\') + if (!was_backslash && (ch == '\n' || ch == '\r')) { + if (i == 0) + continue; /* \r immediately followed by \n */ + + /* + * The de-escaped line should contain an OID followed by exactly + * one space followed by a path. The path might start with + * spaces, so don't be too liberal about parsing. + */ str[i] = '\0'; - if (sscanf(str, "%s %n", tbsoid, &n) != 1) + n = 0; + while (str[n] && str[n] != ' ') + n++; + if (n < 1 || n >= i - 1) ereport(FATAL, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), errmsg("invalid data in file \"%s\"", TABLESPACE_MAP))); - tbslinkpath = str + n; - i = 0; - - ti = palloc(sizeof(tablespaceinfo)); - ti->oid = pstrdup(tbsoid); - ti->path = pstrdup(tbslinkpath); + str[n++] = '\0'; + ti = palloc0(sizeof(tablespaceinfo)); + ti->oid = pstrdup(str); + ti->path = pstrdup(str + n); *tablespaces = lappend(*tablespaces, ti); + + i = 0; continue; } - else if ((ch == '\n' || ch == '\r') && prev_ch == '\\') - str[i - 1] = ch; - else if (i < sizeof(str) - 1) - str[i++] = ch; - prev_ch = ch; + else if (!was_backslash && ch == '\\') + was_backslash = true; + else + { + if (i < sizeof(str) - 1) + str[i++] = ch; + was_backslash = false; + } } + if (i != 0 || was_backslash) /* last line not terminated? */ + ereport(FATAL, + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), + errmsg("invalid data in file \"%s\"", TABLESPACE_MAP))); + if (ferror(lfp) || FreeFile(lfp)) ereport(FATAL, (errcode_for_file_access(), |