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| author | Robert Haas <rhaas@postgresql.org> | 2019-09-06 08:22:32 -0400 |
|---|---|---|
| committer | Robert Haas <rhaas@postgresql.org> | 2019-09-06 09:05:12 -0400 |
| commit | f697c6396d73c1e6d550afed84a6bd8362d9a0d4 (patch) | |
| tree | 359d844d8b238e02c5e043a52f02c50bbeb63cb9 | |
| parent | 62724bd952a2a2a7e114364f5af655f11e21289f (diff) | |
| download | postgresql-f697c6396d73c1e6d550afed84a6bd8362d9a0d4.tar.gz postgresql-f697c6396d73c1e6d550afed84a6bd8362d9a0d4.zip | |
When performing a base backup, check for read errors.
The old code didn't differentiate between a read error and a
concurrent 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 not
sure that would qualify as a back-patchable bug fix, so just do
this much for now.
Jeevan Chalke, reviewed by Jeevan Ladhe and by me.
Discussion: http://postgr.es/m/CA+TgmobG4ywMzL5oQq2a8YKp8x2p3p1LOMMcGqpS7aekT9+ETA@mail.gmail.com
| -rw-r--r-- | src/backend/replication/basebackup.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/src/backend/replication/basebackup.c b/src/backend/replication/basebackup.c index 8259ec5bd89..ddb1de0621d 100644 --- a/src/backend/replication/basebackup.c +++ b/src/backend/replication/basebackup.c @@ -84,6 +84,18 @@ static char *statrelpath = NULL; */ #define THROTTLING_FREQUENCY 8 +/* + * Checks whether we encountered any error in fread(). fread() doesn't give + * any clue what has happened, so we check with ferror(). Also, neither + * fread() nor ferror() set errno, so we just throw a generic error. + */ +#define CHECK_FREAD_ERROR(fp, filename) \ +do { \ + if (ferror(fp)) \ + ereport(ERROR, \ + (errmsg("could not read from file \"%s\"", filename))); \ +} while (0) + /* The actual number of bytes, transfer of which may cause sleep. */ static uint64 throttling_sample; @@ -434,6 +446,8 @@ perform_base_backup(basebackup_options *opt, DIR *tblspcdir) break; } + CHECK_FREAD_ERROR(fp, pathbuf); + if (len != XLogSegSize) { CheckXLogRemoved(segno, tli); @@ -1173,6 +1187,8 @@ sendFile(char *readfilename, char *tarfilename, struct stat * statbuf, } } + CHECK_FREAD_ERROR(fp, readfilename); + /* If the file was truncated while we were sending it, pad it with zeros */ if (len < statbuf->st_size) { |