NotificationsYou must be signed in to change notification settings
Fork6
Star31

Commit61c65cc

committed

When performing a base backup, check for read errors.

The old code didn't differentiate between a read error and aconcurrent truncation. fread reports both of these by returning 0;you have to use feof() or ferror() to distinguish between them,which this code did not do.It might be a better idea to use read() rather than fread() here,so that we can display a less-generic error message, but I'm notsure that would qualify as a back-patchable bug fix, so just dothis much for now.Jeevan Chalke, reviewed by Jeevan Ladhe and by me.Discussion:http://postgr.es/m/CA+TgmobG4ywMzL5oQq2a8YKp8x2p3p1LOMMcGqpS7aekT9+ETA@mail.gmail.com

1 parentaf28744 commit61c65ccCopy full SHA for 61c65cc

File tree

1 file changed

+31

-1

lines changed

src/backend/replication
- basebackup.c

1 file changed

+31

-1

lines changed

`‎src/backend/replication/basebackup.c`

Lines changed: 31 additions & 1 deletion

Original file line number	Diff line number	Diff line change
`@@ -90,6 +90,18 @@ static char *statrelpath = NULL;`
`90`	`90`	`*/`
`91`	`91`	`#defineTHROTTLING_FREQUENCY8`
`92`	`92`
	`93`	`+/*`
	`94`	`+ * Checks whether we encountered any error in fread(). fread() doesn't give`
	`95`	`+ * any clue what has happened, so we check with ferror(). Also, neither`
	`96`	`+ * fread() nor ferror() set errno, so we just throw a generic error.`
	`97`	`+ */`
	`98`	`+#defineCHECK_FREAD_ERROR(fp,filename) \`
	`99`	`+do { \`
	`100`	`+if (ferror(fp)) \`
	`101`	`+ereport(ERROR, \`
	`102`	`+(errmsg("could not read from file \"%s\"", filename))); \`
	`103`	`+} while (0)`
	`104`	`+`
`93`	`105`	`/* The actual number of bytes, transfer of which may cause sleep. */`
`94`	`106`	`staticuint64throttling_sample;`
`95`	`107`
`@@ -550,6 +562,8 @@ perform_base_backup(basebackup_options *opt)`
`550`	`562`	`break;`
`551`	`563`	`}`
`552`	`564`
	`565`	`+CHECK_FREAD_ERROR(fp,pathbuf);`
	`566`	`+`
`553`	`567`	`if (len!=wal_segment_size)`
`554`	`568`	`{`
`555`	`569`	`CheckXLogRemoved(segno,tli);`
`@@ -1487,6 +1501,20 @@ sendFile(const char readfilename, const char tarfilename, struct stat *statbuf`
`1487`	`1501`
`1488`	`1502`	`if (fread(buf+BLCKSZ*i,1,BLCKSZ,fp)!=BLCKSZ)`
`1489`	`1503`	`{`
	`1504`	`+/*`
	`1505`	`+ * If we hit end-of-file, a concurrent`
	`1506`	`+ * truncation must have occurred, so break out`
	`1507`	`+ * of this loop just as if the initial fread()`
	`1508`	`+ * returned 0. We'll drop through to the same`
	`1509`	`+ * code that handles that case. (We must fix`
	`1510`	`+ * up cnt first, though.)`
	`1511`	`+ */`
	`1512`	`+if (feof(fp))`
	`1513`	`+{`
	`1514`	`+cnt=BLCKSZ*i;`
	`1515`	`+break;`
	`1516`	`+}`
	`1517`	`+`
`1490`	`1518`	`ereport(ERROR,`
`1491`	`1519`	`(errcode_for_file_access(),`
`1492`	`1520`	`errmsg("could not reread block %d of file \"%s\": %m",`
`@@ -1538,7 +1566,7 @@ sendFile(const char readfilename, const char tarfilename, struct stat *statbuf`
`1538`	`1566`	`len+=cnt;`
`1539`	`1567`	`throttle(cnt);`
`1540`	`1568`
`1541`		`-if (len >=statbuf->st_size)`
	`1569`	`+if (feof(fp)\|\|len >=statbuf->st_size)`
`1542`	`1570`	`{`
`1543`	`1571`	`/*`
`1544`	`1572`	`* Reached end of file. The file could be longer, if it was`
`@@ -1549,6 +1577,8 @@ sendFile(const char readfilename, const char tarfilename, struct stat *statbuf`
`1549`	`1577`	`}`
`1550`	`1578`	`}`
`1551`	`1579`
	`1580`	`+CHECK_FREAD_ERROR(fp,readfilename);`
	`1581`	`+`
`1552`	`1582`	`/* If the file was truncated while we were sending it, pad it with zeros */`
`1553`	`1583`	`if (len<statbuf->st_size)`
`1554`	`1584`	`{`

0 commit comments

Comments

(0)

Movatterモバイル変換

Navigation Menu

Search code, repositories, users, issues, pull requests...

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

Commit61c65cc

File tree

1 file changed

1 file changed

`‎src/backend/replication/basebackup.c`

0 commit comments