postgres.git / summary / log / commit / refs

commit    794c543b1736f71ff5bc5231eee41cdf460ad8ce
Author:   Thomas Munro <tmunro@postgresql.org>
Date:     Fri Apr 05 03:39:47 2019 +0000
First released in: 12.0

    Fix bugs in mdsyncfiletag().
    
    Commit 3eb77eba moved a _mdfd_getseg() call from mdsync() into a new
    callback function mdsyncfiletag(), but didn't get the arguments quite
    right.  Without the EXTENSION_DONT_CHECK_SIZE flag we fail to open a
    segment if lower-numbered segments have been truncated, and it wants
    a block number rather than a segment number.
    
    While comparing with the older coding, also remove an unnecessary
    clobbering of errno, and adjust the code in mdunlinkfiletag() to
    ressemble the original code from mdpostckpt() more closely instead
    of using an unnecessary call to smgropen().
    
    Author: Thomas Munro
    Discussion: https://postgr.es/m/CA%2BhUKGL%2BYLUOA0eYiBXBfwW%2BbH5kFgh94%3DgQH0jHEJ-t5Y91wQ%40mail.gmail.com


 src/backend/storage/smgr/md.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/src/backend/storage/smgr/md.c b/src/backend/storage/smgr/md.c
index ffb3569698f..61a8f11469b 100644
--- a/src/backend/storage/smgr/md.c
+++ b/src/backend/storage/smgr/md.c
@@ -1266,14 +1266,14 @@ mdsyncfiletag(const FileTag *ftag, char *path)
 	strlcpy(path, p, MAXPGPATH);
 	pfree(p);
 
-	/* Try to find open the requested segment. */
-	v = _mdfd_getseg(reln, ftag->forknum, ftag->segno, false,
-					 EXTENSION_RETURN_NULL);
+	/* Try to open the requested segment. */
+	v = _mdfd_getseg(reln,
+					 ftag->forknum,
+					 ftag->segno * (BlockNumber) RELSEG_SIZE,
+					 false,
+					 EXTENSION_RETURN_NULL | EXTENSION_DONT_CHECK_SIZE);
 	if (v == NULL)
-	{
-		errno = ENOENT;
 		return -1;
-	}
 
 	/* Try to fsync the file. */
 	return FileSync(v->mdfd_vfd, WAIT_EVENT_DATA_FILE_SYNC);
@@ -1288,11 +1288,10 @@ mdsyncfiletag(const FileTag *ftag, char *path)
 int
 mdunlinkfiletag(const FileTag *ftag, char *path)
 {
-	SMgrRelation reln = smgropen(ftag->rnode, InvalidBackendId);
 	char	   *p;
 
 	/* Compute the path. */
-	p = _mdfd_segpath(reln, ftag->forknum, ftag->segno);
+	p = relpathperm(ftag->rnode, MAIN_FORKNUM);
 	strlcpy(path, p, MAXPGPATH);
 	pfree(p);
 


[parent: c46c85d4594d]