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Revert "Use "transient" files for blind writes, take 2".

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This reverts commit fba105b109.
That approach had problems with the smgr-level state not tracking what
we really want to happen, and with the VFD-level state not tracking the
smgr-level state very well either.  In consequence, it was still possible
to hold kernel file descriptors open for long-gone tables (as in recent
report from Tore Halset), and yet there were also cases of FDs being closed
undesirably soon.  A replacement implementation will follow.
This commit is contained in:
Tom Lane
2012-10-17 12:37:15 -04:00
parent 4be1d015b8
commit a1f064fc2b
6 changed files with 28 additions and 102 deletions
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91
src/backend/storage/file/fd.c
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@ -126,8 +126,6 @@ int max_safe_fds = 32; /* default if not changed */
/* these are the assigned bits in fdstate below: */
#define FD_TEMPORARY (1 << 0) /* T = delete when closed */
#define FD_XACT_TEMPORARY (1 << 1) /* T = delete at eoXact */
#define FD_XACT_TRANSIENT (1 << 2) /* T = close (not delete) at aoXact,
* but keep VFD */
typedef struct vfd
{
@ -158,8 +156,11 @@ static Size SizeVfdCache = 0;
*/
static int nfile = 0;
/* True if there are files to close/delete at end of transaction */
static bool have_pending_fd_cleanup = false;
/*
* Flag to tell whether it's worth scanning VfdCache looking for temp files
* to close
*/
static bool have_xact_temporary_files = false;
/*
* Tracks the total size of all temporary files. Note: when temp_file_limit
@ -600,7 +601,6 @@ LruDelete(File file)
Vfd *vfdP;
Assert(file != 0);
Assert(!FileIsNotOpen(file));
DO_DB(elog(LOG, "LruDelete %d (%s)",
file, VfdCache[file].fileName));
@ -964,7 +964,7 @@ OpenTemporaryFile(bool interXact)
VfdCache[file].resowner = CurrentResourceOwner;
/* ensure cleanup happens at eoxact */
have_pending_fd_cleanup = true;
have_xact_temporary_files = true;
}
return file;
@ -1037,25 +1037,6 @@ OpenTemporaryFileInTablespace(Oid tblspcOid, bool rejectError)
return file;
}
/*
* Set the transient flag on a file
*
* This flag tells CleanupTempFiles to close the kernel-level file descriptor
* (but not the VFD itself) at end of transaction.
*/
void
FileSetTransient(File file)
{
Vfd *vfdP;
Assert(FileIsValid(file));
vfdP = &VfdCache[file];
vfdP->fdstate |= FD_XACT_TRANSIENT;
have_pending_fd_cleanup = true;
}
/*
* close a file when done with it
*/
@ -1856,9 +1837,8 @@ AtEOSubXact_Files(bool isCommit, SubTransactionId mySubid,
* particularly care which). All still-open per-transaction temporary file
* VFDs are closed, which also causes the underlying files to be deleted
* (although they should've been closed already by the ResourceOwner
* cleanup). Transient files have their kernel file descriptors closed.
* Furthermore, all "allocated" stdio files are closed. We also forget any
* transaction-local temp tablespace list.
* cleanup). Furthermore, all "allocated" stdio files are closed. We also
* forget any transaction-local temp tablespace list.
*/
void
AtEOXact_Files(void)
@ -1881,10 +1861,7 @@ AtProcExit_Files(int code, Datum arg)
}
/*
* General cleanup routine for fd.c.
*
* Temporary files are closed, and their underlying files deleted.
* Transient files are closed.
* Close temporary files and delete their underlying files.
*
* isProcExit: if true, this is being called as the backend process is
* exiting. If that's the case, we should remove all temporary files; if
@ -1901,51 +1878,35 @@ CleanupTempFiles(bool isProcExit)
* Careful here: at proc_exit we need extra cleanup, not just
* xact_temporary files.
*/
if (isProcExit || have_pending_fd_cleanup)
if (isProcExit || have_xact_temporary_files)
{
Assert(FileIsNotOpen(0)); /* Make sure ring not corrupted */
for (i = 1; i < SizeVfdCache; i++)
{
unsigned short fdstate = VfdCache[i].fdstate;
if (VfdCache[i].fileName != NULL)
if ((fdstate & FD_TEMPORARY) && VfdCache[i].fileName != NULL)
{
if (fdstate & FD_TEMPORARY)
/*
* If we're in the process of exiting a backend process, close
* all temporary files. Otherwise, only close temporary files
* local to the current transaction. They should be closed by
* the ResourceOwner mechanism already, so this is just a
* debugging cross-check.
*/
if (isProcExit)
FileClose(i);
else if (fdstate & FD_XACT_TEMPORARY)
{
/*
* If we're in the process of exiting a backend process,
* close all temporary files. Otherwise, only close
* temporary files local to the current transaction. They
* should be closed by the ResourceOwner mechanism
* already, so this is just a debugging cross-check.
*/
if (isProcExit)
FileClose(i);
else if (fdstate & FD_XACT_TEMPORARY)
{
elog(WARNING,
"temporary file %s not closed at end-of-transaction",
VfdCache[i].fileName);
FileClose(i);
}
}
else if (fdstate & FD_XACT_TRANSIENT)
{
/*
* Close the FD, and remove the entry from the LRU ring,
* but also remove the flag from the VFD. This is to
* ensure that if the VFD is reused in the future for
* non-transient access, we don't close it inappropriately
* then.
*/
if (!FileIsNotOpen(i))
LruDelete(i);
VfdCache[i].fdstate &= ~FD_XACT_TRANSIENT;
elog(WARNING,
"temporary file %s not closed at end-of-transaction",
VfdCache[i].fileName);
FileClose(i);
}
}
}
have_pending_fd_cleanup = false;
have_xact_temporary_files = false;
}
/* Clean up "allocated" stdio files and dirs. */