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Back-patch fix that allows AllocateFile() to return errno=ENFILE/EMFILE

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after we are no longer able to close any more VFDs.  This is needed to
avoid postmaster crash under out-of-file-descriptors conditions.
This commit is contained in:
Tom Lane
2000-09-23 23:31:24 +00:00
parent c954088b83
commit de3e0183b8
1 changed files with 37 additions and 20 deletions
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57
src/backend/storage/file/fd.c
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@ -7,7 +7,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/storage/file/fd.c,v 1.56 2000/04/12 17:15:35 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/storage/file/fd.c,v 1.56.2.1 2000/09/23 23:31:24 tgl Exp $
*
* NOTES:
*
@ -181,7 +181,7 @@ static void Delete(File file);
static void LruDelete(File file);
static void Insert(File file);
static int LruInsert(File file);
static void ReleaseLruFile(void);
static bool ReleaseLruFile(void);
static File AllocateVfd(void);
static void FreeVfd(File file);
@ -347,7 +347,10 @@ LruInsert(File file)
{
while (nfile + numAllocatedFiles >= pg_nofile())
ReleaseLruFile();
{
if (! ReleaseLruFile())
break;
}
/*
* The open could still fail for lack of file descriptors, eg due
@ -358,9 +361,12 @@ tryAgain:
vfdP->fd = open(vfdP->fileName, vfdP->fileFlags, vfdP->fileMode);
if (vfdP->fd < 0 && (errno == EMFILE || errno == ENFILE))
{
int save_errno = errno;
errno = 0;
ReleaseLruFile();
goto tryAgain;
if (ReleaseLruFile())
goto tryAgain;
errno = save_errno;
}
if (vfdP->fd < 0)
@ -392,20 +398,22 @@ tryAgain:
return 0;
}
static void
static bool
ReleaseLruFile()
{
DO_DB(elog(DEBUG, "ReleaseLruFile. Opened %d", nfile));
if (nfile <= 0)
elog(ERROR, "ReleaseLruFile: No open files available to be closed");
/*
* There are opened files and so there should be at least one used vfd
* in the ring.
*/
Assert(VfdCache[0].lruMoreRecently != 0);
LruDelete(VfdCache[0].lruMoreRecently);
if (nfile > 0)
{
/*
* There are opened files and so there should be at least one used
* vfd in the ring.
*/
Assert(VfdCache[0].lruMoreRecently != 0);
LruDelete(VfdCache[0].lruMoreRecently);
return true; /* freed a file */
}
return false; /* no files available to free */
}
/*
@ -612,17 +620,23 @@ fileNameOpenFile(FileName fileName,
vfdP = &VfdCache[file];
while (nfile + numAllocatedFiles >= pg_nofile())
ReleaseLruFile();
{
if (! ReleaseLruFile())
break;
}
tryAgain:
vfdP->fd = open(fileName, fileFlags, fileMode);
if (vfdP->fd < 0 && (errno == EMFILE || errno == ENFILE))
{
int save_errno = errno;
DO_DB(elog(DEBUG, "fileNameOpenFile: not enough descs, retry, er= %d",
errno));
errno = 0;
ReleaseLruFile();
goto tryAgain;
if (ReleaseLruFile())
goto tryAgain;
errno = save_errno;
}
if (vfdP->fd < 0)
@ -1004,11 +1018,14 @@ TryAgain:
{
if (errno == EMFILE || errno == ENFILE)
{
int save_errno = errno;
DO_DB(elog(DEBUG, "AllocateFile: not enough descs, retry, er= %d",
errno));
errno = 0;
ReleaseLruFile();
goto TryAgain;
if (ReleaseLruFile())
goto TryAgain;
errno = save_errno;
}
}
else