* fd.c
* Virtual file descriptor code.
*
- * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
+ * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/storage/file/fd.c,v 1.66 2000/11/10 03:53:44 vadim Exp $
+ * $PostgreSQL: pgsql/src/backend/storage/file/fd.c,v 1.130 2006/10/04 00:29:57 momjian Exp $
*
* NOTES:
*
#include "postgres.h"
-#include <sys/types.h>
#include <sys/file.h>
#include <sys/param.h>
#include <sys/stat.h>
-#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include "miscadmin.h"
+#include "access/xact.h"
#include "storage/fd.h"
+#include "storage/ipc.h"
+
/*
- * Problem: Postgres does a system(ld...) to do dynamic loading.
- * This will open several extra files in addition to those used by
- * Postgres. We need to guarantee that there are file descriptors free
- * for ld to use.
- *
- * The current solution is to limit the number of file descriptors
- * that this code will allocate at one time: it leaves RESERVE_FOR_LD free.
+ * We must leave some file descriptors free for system(), the dynamic loader,
+ * and other code that tries to open files without consulting fd.c. This
+ * is the number left free. (While we can be pretty sure we won't get
+ * EMFILE, there's never any guarantee that we won't get ENFILE due to
+ * other processes chewing up FDs. So it's a bad idea to try to open files
+ * without consulting fd.c. Nonetheless we cannot control all code.)
*
- * (Even though most dynamic loaders now use dlopen(3) or the
- * equivalent, the OS must still open several files to perform the
- * dynamic loading. Keep this here.)
+ * Because this is just a fixed setting, we are effectively assuming that
+ * no such code will leave FDs open over the long term; otherwise the slop
+ * is likely to be insufficient. Note in particular that we expect that
+ * loading a shared library does not result in any permanent increase in
+ * the number of open files. (This appears to be true on most if not
+ * all platforms as of Feb 2004.)
*/
-#ifndef RESERVE_FOR_LD
-#define RESERVE_FOR_LD 10
-#endif
+#define NUM_RESERVED_FDS 10
+
+/*
+ * If we have fewer than this many usable FDs after allowing for the reserved
+ * ones, choke.
+ */
+#define FD_MINFREE 10
+
/*
- * We need to ensure that we have at least some file descriptors
- * available to postgreSQL after we've reserved the ones for LD,
- * so we set that value here.
+ * A number of platforms allow individual processes to open many more files
+ * than they can really support when *many* processes do the same thing.
+ * This GUC parameter lets the DBA limit max_safe_fds to something less than
+ * what the postmaster's initial probe suggests will work.
+ */
+int max_files_per_process = 1000;
+
+/*
+ * Maximum number of file descriptors to open for either VFD entries or
+ * AllocateFile/AllocateDir operations. This is initialized to a conservative
+ * value, and remains that way indefinitely in bootstrap or standalone-backend
+ * cases. In normal postmaster operation, the postmaster calls
+ * set_max_safe_fds() late in initialization to update the value, and that
+ * value is then inherited by forked subprocesses.
*
- * I think 10 is an appropriate value so that's what it'll be
- * for now.
+ * Note: the value of max_files_per_process is taken into account while
+ * setting this variable, and so need not be tested separately.
*/
-#ifndef FD_MINFREE
-#define FD_MINFREE 10
-#endif
+static int max_safe_fds = 32; /* default if not changed */
+
/* Debugging.... */
#define FileIsNotOpen(file) (VfdCache[file].fd == VFD_CLOSED)
-#define FileUnknownPos (-1)
+#define FileUnknownPos (-1L)
+
+/* 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 */
typedef struct vfd
{
signed short fd; /* current FD, or VFD_CLOSED if none */
unsigned short fdstate; /* bitflags for VFD's state */
-
-/* these are the assigned bits in fdstate: */
-#define FD_DIRTY (1 << 0)/* written to, but not yet fsync'd */
-#define FD_TEMPORARY (1 << 1)/* should be unlinked when closed */
-
+ SubTransactionId create_subid; /* for TEMPORARY fds, creating subxact */
File nextFree; /* link to next free VFD, if in freelist */
- File lruMoreRecently;/* doubly linked recency-of-use list */
+ File lruMoreRecently; /* doubly linked recency-of-use list */
File lruLessRecently;
long seekPos; /* current logical file position */
char *fileName; /* name of file, or NULL for unused VFD */
/* NB: fileName is malloc'd, and must be free'd when closing the VFD */
- int fileFlags; /* open(2) flags for opening the file */
+ int fileFlags; /* open(2) flags for (re)opening the file */
int fileMode; /* mode to pass to open(2) */
} Vfd;
static int nfile = 0;
/*
- * List of stdio FILEs opened with AllocateFile.
+ * List of stdio FILEs and <dirent.h> DIRs opened with AllocateFile
+ * and AllocateDir.
*
- * Since we don't want to encourage heavy use of AllocateFile, it seems
- * OK to put a pretty small maximum limit on the number of simultaneously
- * allocated files.
+ * Since we don't want to encourage heavy use of AllocateFile or AllocateDir,
+ * it seems OK to put a pretty small maximum limit on the number of
+ * simultaneously allocated descs.
*/
-#define MAX_ALLOCATED_FILES 32
+#define MAX_ALLOCATED_DESCS 32
-static int numAllocatedFiles = 0;
-static FILE *allocatedFiles[MAX_ALLOCATED_FILES];
+typedef enum
+{
+ AllocateDescFile,
+ AllocateDescDir
+} AllocateDescKind;
+
+typedef struct
+{
+ AllocateDescKind kind;
+ union
+ {
+ FILE *file;
+ DIR *dir;
+ } desc;
+ SubTransactionId create_subid;
+} AllocateDesc;
+
+static int numAllocatedDescs = 0;
+static AllocateDesc allocatedDescs[MAX_ALLOCATED_DESCS];
/*
- * Number of temporary files opened during the current transaction;
+ * Number of temporary files opened during the current session;
* this is used in generation of tempfile names.
*/
static long tempFileCounter = 0;
static void FreeVfd(File file);
static int FileAccess(File file);
-static File fileNameOpenFile(FileName fileName, int fileFlags, int fileMode);
-static char *filepath(char *filename);
-static long pg_nofile(void);
+static char *make_database_relative(const char *filename);
+static void AtProcExit_Files(int code, Datum arg);
+static void CleanupTempFiles(bool isProcExit);
+static void RemovePgTempFilesInDir(const char *tmpdirname);
+
-#ifndef XLOG
/*
- * pg_fsync --- same as fsync except does nothing if -F switch was given
+ * pg_fsync --- do fsync with or without writethrough
*/
int
pg_fsync(int fd)
+{
+#ifndef HAVE_FSYNC_WRITETHROUGH_ONLY
+ if (sync_method != SYNC_METHOD_FSYNC_WRITETHROUGH)
+ return pg_fsync_no_writethrough(fd);
+ else
+#endif
+ return pg_fsync_writethrough(fd);
+}
+
+
+/*
+ * pg_fsync_no_writethrough --- same as fsync except does nothing if
+ * enableFsync is off
+ */
+int
+pg_fsync_no_writethrough(int fd)
{
if (enableFsync)
return fsync(fd);
else
return 0;
}
+
+/*
+ * pg_fsync_writethrough
+ */
+int
+pg_fsync_writethrough(int fd)
+{
+ if (enableFsync)
+ {
+#ifdef WIN32
+ return _commit(fd);
+#elif defined(F_FULLFSYNC)
+ return (fcntl(fd, F_FULLFSYNC, 0) == -1) ? -1 : 0;
+#else
+ return -1;
#endif
+ }
+ else
+ return 0;
+}
+
+/*
+ * pg_fdatasync --- same as fdatasync except does nothing if enableFsync is off
+ *
+ * Not all platforms have fdatasync; treat as fsync if not available.
+ */
+int
+pg_fdatasync(int fd)
+{
+ if (enableFsync)
+ {
+#ifdef HAVE_FDATASYNC
+ return fdatasync(fd);
+#else
+ return fsync(fd);
+#endif
+ }
+ else
+ return 0;
+}
+
+/*
+ * InitFileAccess --- initialize this module during backend startup
+ *
+ * This is called during either normal or standalone backend start.
+ * It is *not* called in the postmaster.
+ */
+void
+InitFileAccess(void)
+{
+ Assert(SizeVfdCache == 0); /* call me only once */
+
+ /* initialize cache header entry */
+ VfdCache = (Vfd *) malloc(sizeof(Vfd));
+ if (VfdCache == NULL)
+ ereport(FATAL,
+ (errcode(ERRCODE_OUT_OF_MEMORY),
+ errmsg("out of memory")));
+
+ MemSet((char *) &(VfdCache[0]), 0, sizeof(Vfd));
+ VfdCache->fd = VFD_CLOSED;
+
+ SizeVfdCache = 1;
+
+ /* register proc-exit hook to ensure temp files are dropped at exit */
+ on_proc_exit(AtProcExit_Files, 0);
+}
+
+/*
+ * count_usable_fds --- count how many FDs the system will let us open,
+ * and estimate how many are already open.
+ *
+ * We stop counting if usable_fds reaches max_to_probe. Note: a small
+ * value of max_to_probe might result in an underestimate of already_open;
+ * we must fill in any "gaps" in the set of used FDs before the calculation
+ * of already_open will give the right answer. In practice, max_to_probe
+ * of a couple of dozen should be enough to ensure good results.
+ *
+ * We assume stdin (FD 0) is available for dup'ing
+ */
+static void
+count_usable_fds(int max_to_probe, int *usable_fds, int *already_open)
+{
+ int *fd;
+ int size;
+ int used = 0;
+ int highestfd = 0;
+ int j;
+
+ size = 1024;
+ fd = (int *) palloc(size * sizeof(int));
+
+ /* dup until failure or probe limit reached */
+ for (;;)
+ {
+ int thisfd;
+
+ thisfd = dup(0);
+ if (thisfd < 0)
+ {
+ /* Expect EMFILE or ENFILE, else it's fishy */
+ if (errno != EMFILE && errno != ENFILE)
+ elog(WARNING, "dup(0) failed after %d successes: %m", used);
+ break;
+ }
+
+ if (used >= size)
+ {
+ size *= 2;
+ fd = (int *) repalloc(fd, size * sizeof(int));
+ }
+ fd[used++] = thisfd;
+
+ if (highestfd < thisfd)
+ highestfd = thisfd;
+
+ if (used >= max_to_probe)
+ break;
+ }
+
+ /* release the files we opened */
+ for (j = 0; j < used; j++)
+ close(fd[j]);
+
+ pfree(fd);
+
+ /*
+ * Return results. usable_fds is just the number of successful dups. We
+ * assume that the system limit is highestfd+1 (remember 0 is a legal FD
+ * number) and so already_open is highestfd+1 - usable_fds.
+ */
+ *usable_fds = used;
+ *already_open = highestfd + 1 - used;
+}
+
+/*
+ * set_max_safe_fds
+ * Determine number of filedescriptors that fd.c is allowed to use
+ */
+void
+set_max_safe_fds(void)
+{
+ int usable_fds;
+ int already_open;
+
+ /*----------
+ * We want to set max_safe_fds to
+ * MIN(usable_fds, max_files_per_process - already_open)
+ * less the slop factor for files that are opened without consulting
+ * fd.c. This ensures that we won't exceed either max_files_per_process
+ * or the experimentally-determined EMFILE limit.
+ *----------
+ */
+ count_usable_fds(max_files_per_process,
+ &usable_fds, &already_open);
+
+ max_safe_fds = Min(usable_fds, max_files_per_process - already_open);
+
+ /*
+ * Take off the FDs reserved for system() etc.
+ */
+ max_safe_fds -= NUM_RESERVED_FDS;
+
+ /*
+ * Make sure we still have enough to get by.
+ */
+ if (max_safe_fds < FD_MINFREE)
+ ereport(FATAL,
+ (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
+ errmsg("insufficient file descriptors available to start server process"),
+ errdetail("System allows %d, we need at least %d.",
+ max_safe_fds + NUM_RESERVED_FDS,
+ FD_MINFREE + NUM_RESERVED_FDS)));
+
+ elog(DEBUG2, "max_safe_fds = %d, usable_fds = %d, already_open = %d",
+ max_safe_fds, usable_fds, already_open);
+}
/*
* BasicOpenFile --- same as open(2) except can free other FDs if needed
* This is exported for use by places that really want a plain kernel FD,
* but need to be proof against running out of FDs. Once an FD has been
* successfully returned, it is the caller's responsibility to ensure that
- * it will not be leaked on elog()! Most users should *not* call this
+ * it will not be leaked on ereport()! Most users should *not* call this
* routine directly, but instead use the VFD abstraction level, which
* provides protection against descriptor leaks as well as management of
* files that need to be open for more than a short period of time.
int
BasicOpenFile(FileName fileName, int fileFlags, int fileMode)
{
- int fd;
+ int fd;
tryAgain:
fd = open(fileName, fileFlags, fileMode);
if (errno == EMFILE || errno == ENFILE)
{
- int save_errno = errno;
+ int save_errno = errno;
- DO_DB(elog(DEBUG, "BasicOpenFile: not enough descs, retry, er= %d",
- errno));
+ ereport(LOG,
+ (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
+ errmsg("out of file descriptors: %m; release and retry")));
errno = 0;
if (ReleaseLruFile())
goto tryAgain;
return -1; /* failure */
}
-/*
- * pg_nofile: determine number of filedescriptors that fd.c is allowed to use
- */
-static long
-pg_nofile(void)
-{
- static long no_files = 0;
-
- if (no_files == 0)
- {
- /* need do this calculation only once */
-#ifndef HAVE_SYSCONF
- no_files = (long) NOFILE;
-#else
- no_files = sysconf(_SC_OPEN_MAX);
- if (no_files == -1)
- {
- elog(DEBUG, "pg_nofile: Unable to get _SC_OPEN_MAX using sysconf(); using %d", NOFILE);
- no_files = (long) NOFILE;
- }
-#endif
-
- if ((no_files - RESERVE_FOR_LD) < FD_MINFREE)
- elog(FATAL, "pg_nofile: insufficient File Descriptors in postmaster to start backend (%ld).\n"
- " O/S allows %ld, Postmaster reserves %d, We need %d (MIN) after that.",
- no_files - RESERVE_FOR_LD, no_files, RESERVE_FOR_LD, FD_MINFREE);
-
- no_files -= RESERVE_FOR_LD;
- }
-
- return no_files;
-}
-
#if defined(FDDEBUG)
static void
Vfd *vfdP = &VfdCache[mru];
char buf[2048];
- sprintf(buf, "LRU: MOST %d ", mru);
+ snprintf(buf, sizeof(buf), "LRU: MOST %d ", mru);
while (mru != 0)
{
mru = vfdP->lruLessRecently;
vfdP = &VfdCache[mru];
- sprintf(buf + strlen(buf), "%d ", mru);
+ snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "%d ", mru);
}
- sprintf(buf + strlen(buf), "LEAST");
- elog(DEBUG, buf);
+ snprintf(buf + strlen(buf), sizeof(buf) - strlen(buf), "LEAST");
+ elog(LOG, buf);
}
-
-#endif /* FDDEBUG */
+#endif /* FDDEBUG */
static void
Delete(File file)
Assert(file != 0);
- DO_DB(elog(DEBUG, "Delete %d (%s)",
+ DO_DB(elog(LOG, "Delete %d (%s)",
file, VfdCache[file].fileName));
DO_DB(_dump_lru());
LruDelete(File file)
{
Vfd *vfdP;
- int returnValue;
Assert(file != 0);
- DO_DB(elog(DEBUG, "LruDelete %d (%s)",
+ DO_DB(elog(LOG, "LruDelete %d (%s)",
file, VfdCache[file].fileName));
vfdP = &VfdCache[file];
/* save the seek position */
vfdP->seekPos = (long) lseek(vfdP->fd, 0L, SEEK_CUR);
- Assert(vfdP->seekPos != -1);
-
- /* if we have written to the file, sync it before closing */
- if (vfdP->fdstate & FD_DIRTY)
- {
- returnValue = pg_fsync(vfdP->fd);
- Assert(returnValue != -1);
- vfdP->fdstate &= ~FD_DIRTY;
- }
+ Assert(vfdP->seekPos != -1L);
/* close the file */
- returnValue = close(vfdP->fd);
- Assert(returnValue != -1);
+ if (close(vfdP->fd))
+ elog(ERROR, "failed to close \"%s\": %m",
+ vfdP->fileName);
--nfile;
vfdP->fd = VFD_CLOSED;
Assert(file != 0);
- DO_DB(elog(DEBUG, "Insert %d (%s)",
+ DO_DB(elog(LOG, "Insert %d (%s)",
file, VfdCache[file].fileName));
DO_DB(_dump_lru());
DO_DB(_dump_lru());
}
+/* returns 0 on success, -1 on re-open failure (with errno set) */
static int
LruInsert(File file)
{
Vfd *vfdP;
- int returnValue;
Assert(file != 0);
- DO_DB(elog(DEBUG, "LruInsert %d (%s)",
+ DO_DB(elog(LOG, "LruInsert %d (%s)",
file, VfdCache[file].fileName));
vfdP = &VfdCache[file];
if (FileIsNotOpen(file))
{
- while (nfile + numAllocatedFiles >= pg_nofile())
+ while (nfile + numAllocatedDescs >= max_safe_fds)
{
- if (! ReleaseLruFile())
+ if (!ReleaseLruFile())
break;
}
/*
- * The open could still fail for lack of file descriptors, eg due
- * to overall system file table being full. So, be prepared to
- * release another FD if necessary...
+ * The open could still fail for lack of file descriptors, eg due to
+ * overall system file table being full. So, be prepared to release
+ * another FD if necessary...
*/
vfdP->fd = BasicOpenFile(vfdP->fileName, vfdP->fileFlags,
vfdP->fileMode);
if (vfdP->fd < 0)
{
- DO_DB(elog(DEBUG, "RE_OPEN FAILED: %d", errno));
+ DO_DB(elog(LOG, "RE_OPEN FAILED: %d", errno));
return vfdP->fd;
}
else
{
- DO_DB(elog(DEBUG, "RE_OPEN SUCCESS"));
+ DO_DB(elog(LOG, "RE_OPEN SUCCESS"));
++nfile;
}
/* seek to the right position */
if (vfdP->seekPos != 0L)
{
- returnValue = lseek(vfdP->fd, vfdP->seekPos, SEEK_SET);
- Assert(returnValue != -1);
+ long returnValue;
+
+ returnValue = (long) lseek(vfdP->fd, vfdP->seekPos, SEEK_SET);
+ Assert(returnValue != -1L);
}
}
static bool
ReleaseLruFile(void)
{
- DO_DB(elog(DEBUG, "ReleaseLruFile. Opened %d", nfile));
+ DO_DB(elog(LOG, "ReleaseLruFile. Opened %d", nfile));
if (nfile > 0)
{
/*
- * There are opened files and so there should be at least one used
- * vfd in the ring.
+ * 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);
Index i;
File file;
- DO_DB(elog(DEBUG, "AllocateVfd. Size %d", SizeVfdCache));
+ DO_DB(elog(LOG, "AllocateVfd. Size %lu", SizeVfdCache));
- if (SizeVfdCache == 0)
- {
- /* initialize header entry first time through */
- VfdCache = (Vfd *) malloc(sizeof(Vfd));
- Assert(VfdCache != NULL);
- MemSet((char *) &(VfdCache[0]), 0, sizeof(Vfd));
- VfdCache->fd = VFD_CLOSED;
-
- SizeVfdCache = 1;
-
- /*
- * register proc-exit call to ensure temp files are dropped at
- * exit
- */
- on_proc_exit(AtEOXact_Files, 0);
- }
+ Assert(SizeVfdCache > 0); /* InitFileAccess not called? */
if (VfdCache[0].nextFree == 0)
{
-
/*
- * The free list is empty so it is time to increase the size of
- * the array. We choose to double it each time this happens.
- * However, there's not much point in starting *real* small.
+ * The free list is empty so it is time to increase the size of the
+ * array. We choose to double it each time this happens. However,
+ * there's not much point in starting *real* small.
*/
Size newCacheSize = SizeVfdCache * 2;
+ Vfd *newVfdCache;
if (newCacheSize < 32)
newCacheSize = 32;
- VfdCache = (Vfd *) realloc(VfdCache, sizeof(Vfd) * newCacheSize);
- Assert(VfdCache != NULL);
+ /*
+ * Be careful not to clobber VfdCache ptr if realloc fails.
+ */
+ newVfdCache = (Vfd *) realloc(VfdCache, sizeof(Vfd) * newCacheSize);
+ if (newVfdCache == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_OUT_OF_MEMORY),
+ errmsg("out of memory")));
+ VfdCache = newVfdCache;
/*
* Initialize the new entries and link them into the free list.
*/
-
for (i = SizeVfdCache; i < newCacheSize; i++)
{
MemSet((char *) &(VfdCache[i]), 0, sizeof(Vfd));
/*
* Record the new size
*/
-
SizeVfdCache = newCacheSize;
}
{
Vfd *vfdP = &VfdCache[file];
- DO_DB(elog(DEBUG, "FreeVfd: %d (%s)",
+ DO_DB(elog(LOG, "FreeVfd: %d (%s)",
file, vfdP->fileName ? vfdP->fileName : ""));
if (vfdP->fileName != NULL)
free(vfdP->fileName);
vfdP->fileName = NULL;
}
+ vfdP->fdstate = 0x0;
vfdP->nextFree = VfdCache[0].nextFree;
VfdCache[0].nextFree = file;
}
-/* filepath()
- * Convert given pathname to absolute.
+/*
+ * make_database_relative()
+ * Prepend DatabasePath to the given file name.
*
- * (Generally, this isn't actually necessary, considering that we
- * should be cd'd into the database directory. Presently it is only
- * necessary to do it in "bootstrap" mode. Maybe we should change
- * bootstrap mode to do the cd, and save a few cycles/bytes here.)
+ * Result is a palloc'd string.
*/
static char *
-filepath(char *filename)
+make_database_relative(const char *filename)
{
char *buf;
- int len;
-
- /* Not an absolute path name? Then fill in with database path... */
- if (*filename != SEP_CHAR)
- {
- len = strlen(DatabasePath) + strlen(filename) + 2;
- buf = (char *) palloc(len);
- sprintf(buf, "%s%c%s", DatabasePath, SEP_CHAR, filename);
- }
- else
- {
- buf = (char *) palloc(strlen(filename) + 1);
- strcpy(buf, filename);
- }
-
-#ifdef FILEDEBUG
- printf("filepath: path is %s\n", buf);
-#endif
+ Assert(!is_absolute_path(filename));
+ buf = (char *) palloc(strlen(DatabasePath) + strlen(filename) + 2);
+ sprintf(buf, "%s/%s", DatabasePath, filename);
return buf;
}
+/* returns 0 on success, -1 on re-open failure (with errno set) */
static int
FileAccess(File file)
{
int returnValue;
- DO_DB(elog(DEBUG, "FileAccess %d (%s)",
+ DO_DB(elog(LOG, "FileAccess %d (%s)",
file, VfdCache[file].fileName));
/*
- * Is the file open? If not, open it and put it at the head of the
- * LRU ring (possibly closing the least recently used file to get an
- * FD).
+ * Is the file open? If not, open it and put it at the head of the LRU
+ * ring (possibly closing the least recently used file to get an FD).
*/
if (FileIsNotOpen(file))
}
else if (VfdCache[0].lruLessRecently != file)
{
-
/*
- * We now know that the file is open and that it is not the last
- * one accessed, so we need to move it to the head of the Lru
- * ring.
+ * We now know that the file is open and that it is not the last one
+ * accessed, so we need to move it to the head of the Lru ring.
*/
Delete(file);
if (!FileIsNotOpen(file))
LruDelete(file);
}
-
#endif
-static File
-fileNameOpenFile(FileName fileName,
- int fileFlags,
- int fileMode)
+/*
+ * open a file in an arbitrary directory
+ *
+ * NB: if the passed pathname is relative (which it usually is),
+ * it will be interpreted relative to the process' working directory
+ * (which should always be $PGDATA when this code is running).
+ */
+File
+PathNameOpenFile(FileName fileName, int fileFlags, int fileMode)
{
+ char *fnamecopy;
File file;
Vfd *vfdP;
- if (fileName == NULL)
- elog(ERROR, "fileNameOpenFile: NULL fname");
-
- DO_DB(elog(DEBUG, "fileNameOpenFile: %s %x %o",
+ DO_DB(elog(LOG, "PathNameOpenFile: %s %x %o",
fileName, fileFlags, fileMode));
+ /*
+ * We need a malloc'd copy of the file name; fail cleanly if no room.
+ */
+ fnamecopy = strdup(fileName);
+ if (fnamecopy == NULL)
+ ereport(ERROR,
+ (errcode(ERRCODE_OUT_OF_MEMORY),
+ errmsg("out of memory")));
+
file = AllocateVfd();
vfdP = &VfdCache[file];
- while (nfile + numAllocatedFiles >= pg_nofile())
+ while (nfile + numAllocatedDescs >= max_safe_fds)
{
- if (! ReleaseLruFile())
+ if (!ReleaseLruFile())
break;
}
if (vfdP->fd < 0)
{
FreeVfd(file);
+ free(fnamecopy);
return -1;
}
++nfile;
- DO_DB(elog(DEBUG, "fileNameOpenFile: success %d",
+ DO_DB(elog(LOG, "PathNameOpenFile: success %d",
vfdP->fd));
Insert(file);
- vfdP->fileName = malloc(strlen(fileName) + 1);
- strcpy(vfdP->fileName, fileName);
-
- vfdP->fileFlags = fileFlags & ~(O_TRUNC | O_EXCL);
+ vfdP->fileName = fnamecopy;
+ /* Saved flags are adjusted to be OK for re-opening file */
+ vfdP->fileFlags = fileFlags & ~(O_CREAT | O_TRUNC | O_EXCL);
vfdP->fileMode = fileMode;
vfdP->seekPos = 0;
-#ifdef XLOG
- /*
- * Have to fsync file on commit. Alternative way - log
- * file creation and fsync log before actual file creation.
- */
- if (fileFlags & O_CREAT)
- vfdP->fdstate = FD_DIRTY;
-#else
vfdP->fdstate = 0x0;
-#endif
return file;
}
/*
- * open a file in the database directory ($PGDATA/base/...)
+ * open a file in the database directory ($PGDATA/base/DIROID/)
+ *
+ * The passed name MUST be a relative path. Effectively, this
+ * prepends DatabasePath to it and then acts like PathNameOpenFile.
*/
File
FileNameOpenFile(FileName fileName, int fileFlags, int fileMode)
File fd;
char *fname;
- fname = filepath(fileName);
- fd = fileNameOpenFile(fname, fileFlags, fileMode);
+ fname = make_database_relative(fileName);
+ fd = PathNameOpenFile(fname, fileFlags, fileMode);
pfree(fname);
return fd;
}
-/*
- * open a file in an arbitrary directory
- */
-File
-PathNameOpenFile(FileName fileName, int fileFlags, int fileMode)
-{
- return fileNameOpenFile(fileName, fileFlags, fileMode);
-}
-
/*
* Open a temporary file that will disappear when we close it.
*
* This routine takes care of generating an appropriate tempfile name.
* There's no need to pass in fileFlags or fileMode either, since only
* one setting makes any sense for a temp file.
+ *
+ * interXact: if true, don't close the file at end-of-transaction. In
+ * most cases, you don't want temporary files to outlive the transaction
+ * that created them, so this should be false -- but if you need
+ * "somewhat" temporary storage, this might be useful. In either case,
+ * the file is removed when the File is explicitly closed.
*/
File
-OpenTemporaryFile(void)
+OpenTemporaryFile(bool interXact)
{
- char tempfilename[64];
+ char tempfilepath[MAXPGPATH];
File file;
/*
- * Generate a tempfile name that's unique within the current
- * transaction
+ * Generate a tempfile name that should be unique within the current
+ * database instance.
*/
- snprintf(tempfilename, sizeof(tempfilename),
- "pg_sorttemp%d.%ld", MyProcPid, tempFileCounter++);
+ snprintf(tempfilepath, sizeof(tempfilepath),
+ "%s/%s%d.%ld", PG_TEMP_FILES_DIR, PG_TEMP_FILE_PREFIX,
+ MyProcPid, tempFileCounter++);
- /* Open the file */
- file = FileNameOpenFile(tempfilename,
- O_RDWR | O_CREAT | O_TRUNC | PG_BINARY, 0600);
+ /*
+ * Open the file. Note: we don't use O_EXCL, in case there is an orphaned
+ * temp file that can be reused.
+ */
+ file = FileNameOpenFile(tempfilepath,
+ O_RDWR | O_CREAT | O_TRUNC | PG_BINARY,
+ 0600);
if (file <= 0)
- elog(ERROR, "Failed to create temporary file %s", tempfilename);
+ {
+ char *dirpath;
+
+ /*
+ * We might need to create the pg_tempfiles subdirectory, if no one
+ * has yet done so.
+ *
+ * Don't check for error from mkdir; it could fail if someone else
+ * just did the same thing. If it doesn't work then we'll bomb out on
+ * the second create attempt, instead.
+ */
+ dirpath = make_database_relative(PG_TEMP_FILES_DIR);
+ mkdir(dirpath, S_IRWXU);
+ pfree(dirpath);
+
+ file = FileNameOpenFile(tempfilepath,
+ O_RDWR | O_CREAT | O_TRUNC | PG_BINARY,
+ 0600);
+ if (file <= 0)
+ elog(ERROR, "could not create temporary file \"%s\": %m",
+ tempfilepath);
+ }
- /* Mark it for deletion at close or EOXact */
+ /* Mark it for deletion at close */
VfdCache[file].fdstate |= FD_TEMPORARY;
+ /* Mark it for deletion at EOXact */
+ if (!interXact)
+ {
+ VfdCache[file].fdstate |= FD_XACT_TEMPORARY;
+ VfdCache[file].create_subid = GetCurrentSubTransactionId();
+ }
+
return file;
}
void
FileClose(File file)
{
- int returnValue;
+ Vfd *vfdP;
Assert(FileIsValid(file));
- DO_DB(elog(DEBUG, "FileClose: %d (%s)",
+ DO_DB(elog(LOG, "FileClose: %d (%s)",
file, VfdCache[file].fileName));
+ vfdP = &VfdCache[file];
+
if (!FileIsNotOpen(file))
{
-
/* remove the file from the lru ring */
Delete(file);
- /* if we did any writes, sync the file before closing */
- if (VfdCache[file].fdstate & FD_DIRTY)
- {
- returnValue = pg_fsync(VfdCache[file].fd);
- Assert(returnValue != -1);
- VfdCache[file].fdstate &= ~FD_DIRTY;
- }
-
/* close the file */
- returnValue = close(VfdCache[file].fd);
- Assert(returnValue != -1);
+ if (close(vfdP->fd))
+ elog(ERROR, "failed to close \"%s\": %m",
+ vfdP->fileName);
--nfile;
- VfdCache[file].fd = VFD_CLOSED;
+ vfdP->fd = VFD_CLOSED;
}
/*
* Delete the file if it was temporary
*/
- if (VfdCache[file].fdstate & FD_TEMPORARY)
- unlink(VfdCache[file].fileName);
+ if (vfdP->fdstate & FD_TEMPORARY)
+ {
+ /* reset flag so that die() interrupt won't cause problems */
+ vfdP->fdstate &= ~FD_TEMPORARY;
+ if (unlink(vfdP->fileName))
+ elog(LOG, "failed to unlink \"%s\": %m",
+ vfdP->fileName);
+ }
/*
* Return the Vfd slot to the free list
{
Assert(FileIsValid(file));
- DO_DB(elog(DEBUG, "FileUnlink: %d (%s)",
+ DO_DB(elog(LOG, "FileUnlink: %d (%s)",
file, VfdCache[file].fileName));
/* force FileClose to delete it */
Assert(FileIsValid(file));
- DO_DB(elog(DEBUG, "FileRead: %d (%s) %d %p",
- file, VfdCache[file].fileName, amount, buffer));
+ DO_DB(elog(LOG, "FileRead: %d (%s) %ld %d %p",
+ file, VfdCache[file].fileName,
+ VfdCache[file].seekPos, amount, buffer));
- FileAccess(file);
+ returnCode = FileAccess(file);
+ if (returnCode < 0)
+ return returnCode;
+
+retry:
returnCode = read(VfdCache[file].fd, buffer, amount);
- if (returnCode > 0)
+
+ if (returnCode >= 0)
VfdCache[file].seekPos += returnCode;
else
+ {
+ /*
+ * Windows may run out of kernel buffers and return "Insufficient
+ * system resources" error. Wait a bit and retry to solve it.
+ *
+ * It is rumored that EINTR is also possible on some Unix filesystems,
+ * in which case immediate retry is indicated.
+ */
+#ifdef WIN32
+ DWORD error = GetLastError();
+
+ switch (error)
+ {
+ case ERROR_NO_SYSTEM_RESOURCES:
+ pg_usleep(1000L);
+ errno = EINTR;
+ break;
+ default:
+ _dosmaperr(error);
+ break;
+ }
+#endif
+ /* OK to retry if interrupted */
+ if (errno == EINTR)
+ goto retry;
+
+ /* Trouble, so assume we don't know the file position anymore */
VfdCache[file].seekPos = FileUnknownPos;
+ }
return returnCode;
}
Assert(FileIsValid(file));
- DO_DB(elog(DEBUG, "FileWrite: %d (%s) %d %p",
- file, VfdCache[file].fileName, amount, buffer));
+ DO_DB(elog(LOG, "FileWrite: %d (%s) %ld %d %p",
+ file, VfdCache[file].fileName,
+ VfdCache[file].seekPos, amount, buffer));
- FileAccess(file);
+ returnCode = FileAccess(file);
+ if (returnCode < 0)
+ return returnCode;
+
+retry:
+ errno = 0;
returnCode = write(VfdCache[file].fd, buffer, amount);
- if (returnCode > 0)
- {
+
+ /* if write didn't set errno, assume problem is no disk space */
+ if (returnCode != amount && errno == 0)
+ errno = ENOSPC;
+
+ if (returnCode >= 0)
VfdCache[file].seekPos += returnCode;
-#ifndef XLOG
- /* mark the file as needing fsync */
- VfdCache[file].fdstate |= FD_DIRTY;
-#endif
- }
else
+ {
+ /*
+ * See comments in FileRead()
+ */
+#ifdef WIN32
+ DWORD error = GetLastError();
+
+ switch (error)
+ {
+ case ERROR_NO_SYSTEM_RESOURCES:
+ pg_usleep(1000L);
+ errno = EINTR;
+ break;
+ default:
+ _dosmaperr(error);
+ break;
+ }
+#endif
+ /* OK to retry if interrupted */
+ if (errno == EINTR)
+ goto retry;
+
+ /* Trouble, so assume we don't know the file position anymore */
VfdCache[file].seekPos = FileUnknownPos;
+ }
return returnCode;
}
+int
+FileSync(File file)
+{
+ int returnCode;
+
+ Assert(FileIsValid(file));
+
+ DO_DB(elog(LOG, "FileSync: %d (%s)",
+ file, VfdCache[file].fileName));
+
+ returnCode = FileAccess(file);
+ if (returnCode < 0)
+ return returnCode;
+
+ return pg_fsync(VfdCache[file].fd);
+}
+
long
FileSeek(File file, long offset, int whence)
{
+ int returnCode;
+
Assert(FileIsValid(file));
- DO_DB(elog(DEBUG, "FileSeek: %d (%s) %ld %d",
- file, VfdCache[file].fileName, offset, whence));
+ DO_DB(elog(LOG, "FileSeek: %d (%s) %ld %ld %d",
+ file, VfdCache[file].fileName,
+ VfdCache[file].seekPos, offset, whence));
if (FileIsNotOpen(file))
{
{
case SEEK_SET:
if (offset < 0)
- elog(ERROR, "FileSeek: invalid offset: %ld", offset);
+ elog(ERROR, "invalid seek offset: %ld", offset);
VfdCache[file].seekPos = offset;
break;
case SEEK_CUR:
VfdCache[file].seekPos += offset;
break;
case SEEK_END:
- FileAccess(file);
- VfdCache[file].seekPos = lseek(VfdCache[file].fd, offset, whence);
+ returnCode = FileAccess(file);
+ if (returnCode < 0)
+ return returnCode;
+ VfdCache[file].seekPos = lseek(VfdCache[file].fd,
+ offset, whence);
break;
default:
- elog(ERROR, "FileSeek: invalid whence: %d", whence);
+ elog(ERROR, "invalid whence: %d", whence);
break;
}
}
{
case SEEK_SET:
if (offset < 0)
- elog(ERROR, "FileSeek: invalid offset: %ld", offset);
+ elog(ERROR, "invalid seek offset: %ld", offset);
if (VfdCache[file].seekPos != offset)
- VfdCache[file].seekPos = lseek(VfdCache[file].fd, offset, whence);
+ VfdCache[file].seekPos = lseek(VfdCache[file].fd,
+ offset, whence);
break;
case SEEK_CUR:
if (offset != 0 || VfdCache[file].seekPos == FileUnknownPos)
- VfdCache[file].seekPos = lseek(VfdCache[file].fd, offset, whence);
+ VfdCache[file].seekPos = lseek(VfdCache[file].fd,
+ offset, whence);
break;
case SEEK_END:
- VfdCache[file].seekPos = lseek(VfdCache[file].fd, offset, whence);
+ VfdCache[file].seekPos = lseek(VfdCache[file].fd,
+ offset, whence);
break;
default:
- elog(ERROR, "FileSeek: invalid whence: %d", whence);
+ elog(ERROR, "invalid whence: %d", whence);
break;
}
}
FileTell(File file)
{
Assert(FileIsValid(file));
- DO_DB(elog(DEBUG, "FileTell %d (%s)",
+ DO_DB(elog(LOG, "FileTell %d (%s)",
file, VfdCache[file].fileName));
return VfdCache[file].seekPos;
}
-
#endif
int
Assert(FileIsValid(file));
- DO_DB(elog(DEBUG, "FileTruncate %d (%s)",
+ DO_DB(elog(LOG, "FileTruncate %d (%s)",
file, VfdCache[file].fileName));
- FileSync(file);
- FileAccess(file);
+ returnCode = FileAccess(file);
+ if (returnCode < 0)
+ return returnCode;
+
returnCode = ftruncate(VfdCache[file].fd, (size_t) offset);
return returnCode;
}
+
/*
- * FileSync --- if a file is marked as dirty, fsync it.
- *
- * The FD_DIRTY bit is slightly misnamed: it doesn't mean that we need to
- * write the file, but that we *have* written it and need to execute an
- * fsync() to ensure the changes are down on disk before we mark the current
- * transaction committed.
- *
- * FD_DIRTY is set by FileWrite or by an explicit FileMarkDirty() call.
- * It is cleared after successfully fsync'ing the file. FileClose() will
- * fsync a dirty File that is about to be closed, since there will be no
- * other place to remember the need to fsync after the VFD is gone.
+ * Routines that want to use stdio (ie, FILE*) should use AllocateFile
+ * rather than plain fopen(). This lets fd.c deal with freeing FDs if
+ * necessary to open the file. When done, call FreeFile rather than fclose.
*
- * Note that the DIRTY bit is logically associated with the actual disk file,
- * not with any particular kernel FD we might have open for it. We assume
- * that fsync will force out any dirty buffers for that file, whether or not
- * they were written through the FD being used for the fsync call --- they
- * might even have been written by some other backend!
+ * Note that files that will be open for any significant length of time
+ * should NOT be handled this way, since they cannot share kernel file
+ * descriptors with other files; there is grave risk of running out of FDs
+ * if anyone locks down too many FDs. Most callers of this routine are
+ * simply reading a config file that they will read and close immediately.
*
- * Note also that LruDelete currently fsyncs a dirty file that it is about
- * to close the kernel file descriptor for. The idea there is to avoid
- * having to re-open the kernel descriptor later. But it's not real clear
- * that this is a performance win; we could end up fsyncing the same file
- * multiple times in a transaction, which would probably cost more time
- * than is saved by avoiding an open() call. This should be studied.
+ * fd.c will automatically close all files opened with AllocateFile at
+ * transaction commit or abort; this prevents FD leakage if a routine
+ * that calls AllocateFile is terminated prematurely by ereport(ERROR).
*
- * This routine used to think it could skip the fsync if the file is
- * physically closed, but that is now WRONG; see comments for FileMarkDirty.
+ * Ideally this should be the *only* direct call of fopen() in the backend.
*/
-int
-FileSync(File file)
+FILE *
+AllocateFile(const char *name, const char *mode)
{
- int returnCode;
+ FILE *file;
- Assert(FileIsValid(file));
+ DO_DB(elog(LOG, "AllocateFile: Allocated %d (%s)",
+ numAllocatedDescs, name));
+
+ /*
+ * The test against MAX_ALLOCATED_DESCS prevents us from overflowing
+ * allocatedFiles[]; the test against max_safe_fds prevents AllocateFile
+ * from hogging every one of the available FDs, which'd lead to infinite
+ * looping.
+ */
+ if (numAllocatedDescs >= MAX_ALLOCATED_DESCS ||
+ numAllocatedDescs >= max_safe_fds - 1)
+ elog(ERROR, "too many private files demanded");
- if (!(VfdCache[file].fdstate & FD_DIRTY))
+TryAgain:
+ if ((file = fopen(name, mode)) != NULL)
{
- /* Need not sync if file is not dirty. */
- returnCode = 0;
+ AllocateDesc *desc = &allocatedDescs[numAllocatedDescs];
+
+ desc->kind = AllocateDescFile;
+ desc->desc.file = file;
+ desc->create_subid = GetCurrentSubTransactionId();
+ numAllocatedDescs++;
+ return desc->desc.file;
}
- else if (!enableFsync)
+
+ if (errno == EMFILE || errno == ENFILE)
{
- /* Don't force the file open if pg_fsync isn't gonna sync it. */
- returnCode = 0;
- VfdCache[file].fdstate &= ~FD_DIRTY;
+ int save_errno = errno;
+
+ ereport(LOG,
+ (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
+ errmsg("out of file descriptors: %m; release and retry")));
+ errno = 0;
+ if (ReleaseLruFile())
+ goto TryAgain;
+ errno = save_errno;
}
- else
+
+ /*
+ * TEMPORARY hack to log the Windows error code on fopen failures, in
+ * hopes of diagnosing some hard-to-reproduce problems.
+ */
+#ifdef WIN32
{
+ int save_errno = errno;
- /*
- * We don't use FileAccess() because we don't want to force the
- * file to the front of the LRU ring; we aren't expecting to
- * access it again soon.
- */
- if (FileIsNotOpen(file))
- {
- returnCode = LruInsert(file);
- if (returnCode != 0)
- return returnCode;
- }
- returnCode = pg_fsync(VfdCache[file].fd);
- if (returnCode == 0)
- VfdCache[file].fdstate &= ~FD_DIRTY;
+ elog(LOG, "Windows fopen(\"%s\",\"%s\") failed: code %lu, errno %d",
+ name, mode, GetLastError(), save_errno);
+ errno = save_errno;
}
+#endif
- return returnCode;
+ return NULL;
}
/*
- * FileMarkDirty --- mark a file as needing fsync at transaction commit.
+ * Free an AllocateDesc of either type.
*
- * Since FileWrite marks the file dirty, this routine is not needed in
- * normal use. It is called when the buffer manager detects that some other
- * backend has written out a shared buffer that this backend dirtied (but
- * didn't write) in the current xact. In that scenario, we need to fsync
- * the file before we can commit. We cannot assume that the other backend
- * has fsync'd the file yet; we need to do our own fsync to ensure that
- * (a) the disk page is written and (b) this backend's commit is delayed
- * until the write is complete.
+ * The argument *must* point into the allocatedDescs[] array.
+ */
+static int
+FreeDesc(AllocateDesc *desc)
+{
+ int result;
+
+ /* Close the underlying object */
+ switch (desc->kind)
+ {
+ case AllocateDescFile:
+ result = fclose(desc->desc.file);
+ break;
+ case AllocateDescDir:
+ result = closedir(desc->desc.dir);
+ break;
+ default:
+ elog(ERROR, "AllocateDesc kind not recognized");
+ result = 0; /* keep compiler quiet */
+ break;
+ }
+
+ /* Compact storage in the allocatedDescs array */
+ numAllocatedDescs--;
+ *desc = allocatedDescs[numAllocatedDescs];
+
+ return result;
+}
+
+/*
+ * Close a file returned by AllocateFile.
*
- * Note we are assuming that an fsync issued by this backend will write
- * kernel disk buffers that were dirtied by another backend. Furthermore,
- * it doesn't matter whether we currently have the file physically open;
- * we must fsync even if we have to re-open the file to do it.
+ * Note we do not check fclose's return value --- it is up to the caller
+ * to handle close errors.
*/
-void
-FileMarkDirty(File file)
+int
+FreeFile(FILE *file)
{
- Assert(FileIsValid(file));
+ int i;
- DO_DB(elog(DEBUG, "FileMarkDirty: %d (%s)",
- file, VfdCache[file].fileName));
+ DO_DB(elog(LOG, "FreeFile: Allocated %d", numAllocatedDescs));
+
+ /* Remove file from list of allocated files, if it's present */
+ for (i = numAllocatedDescs; --i >= 0;)
+ {
+ AllocateDesc *desc = &allocatedDescs[i];
+
+ if (desc->kind == AllocateDescFile && desc->desc.file == file)
+ return FreeDesc(desc);
+ }
- VfdCache[file].fdstate |= FD_DIRTY;
+ /* Only get here if someone passes us a file not in allocatedDescs */
+ elog(WARNING, "file passed to FreeFile was not obtained from AllocateFile");
+
+ return fclose(file);
}
/*
- * Routines that want to use stdio (ie, FILE*) should use AllocateFile
- * rather than plain fopen(). This lets fd.c deal with freeing FDs if
- * necessary to open the file. When done, call FreeFile rather than fclose.
- *
- * Note that files that will be open for any significant length of time
- * should NOT be handled this way, since they cannot share kernel file
- * descriptors with other files; there is grave risk of running out of FDs
- * if anyone locks down too many FDs. Most callers of this routine are
- * simply reading a config file that they will read and close immediately.
- *
- * fd.c will automatically close all files opened with AllocateFile at
- * transaction commit or abort; this prevents FD leakage if a routine
- * that calls AllocateFile is terminated prematurely by elog(ERROR).
+ * Routines that want to use <dirent.h> (ie, DIR*) should use AllocateDir
+ * rather than plain opendir(). This lets fd.c deal with freeing FDs if
+ * necessary to open the directory, and with closing it after an elog.
+ * When done, call FreeDir rather than closedir.
*
- * Ideally this should be the *only* direct call of fopen() in the backend.
+ * Ideally this should be the *only* direct call of opendir() in the backend.
*/
-
-FILE *
-AllocateFile(char *name, char *mode)
+DIR *
+AllocateDir(const char *dirname)
{
- FILE *file;
+ DIR *dir;
- DO_DB(elog(DEBUG, "AllocateFile: Allocated %d", numAllocatedFiles));
+ DO_DB(elog(LOG, "AllocateDir: Allocated %d (%s)",
+ numAllocatedDescs, dirname));
- if (numAllocatedFiles >= MAX_ALLOCATED_FILES)
- elog(ERROR, "AllocateFile: too many private FDs demanded");
+ /*
+ * The test against MAX_ALLOCATED_DESCS prevents us from overflowing
+ * allocatedDescs[]; the test against max_safe_fds prevents AllocateDir
+ * from hogging every one of the available FDs, which'd lead to infinite
+ * looping.
+ */
+ if (numAllocatedDescs >= MAX_ALLOCATED_DESCS ||
+ numAllocatedDescs >= max_safe_fds - 1)
+ elog(ERROR, "too many private dirs demanded");
TryAgain:
- if ((file = fopen(name, mode)) != NULL)
+ if ((dir = opendir(dirname)) != NULL)
{
- allocatedFiles[numAllocatedFiles++] = file;
- return file;
+ AllocateDesc *desc = &allocatedDescs[numAllocatedDescs];
+
+ desc->kind = AllocateDescDir;
+ desc->desc.dir = dir;
+ desc->create_subid = GetCurrentSubTransactionId();
+ numAllocatedDescs++;
+ return desc->desc.dir;
}
if (errno == EMFILE || errno == ENFILE)
{
- int save_errno = errno;
+ int save_errno = errno;
- DO_DB(elog(DEBUG, "AllocateFile: not enough descs, retry, er= %d",
- errno));
+ ereport(LOG,
+ (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
+ errmsg("out of file descriptors: %m; release and retry")));
errno = 0;
if (ReleaseLruFile())
goto TryAgain;
return NULL;
}
-void
-FreeFile(FILE *file)
+/*
+ * Read a directory opened with AllocateDir, ereport'ing any error.
+ *
+ * This is easier to use than raw readdir() since it takes care of some
+ * otherwise rather tedious and error-prone manipulation of errno. Also,
+ * if you are happy with a generic error message for AllocateDir failure,
+ * you can just do
+ *
+ * dir = AllocateDir(path);
+ * while ((dirent = ReadDir(dir, path)) != NULL)
+ * process dirent;
+ * FreeDir(dir);
+ *
+ * since a NULL dir parameter is taken as indicating AllocateDir failed.
+ * (Make sure errno hasn't been changed since AllocateDir if you use this
+ * shortcut.)
+ *
+ * The pathname passed to AllocateDir must be passed to this routine too,
+ * but it is only used for error reporting.
+ */
+struct dirent *
+ReadDir(DIR *dir, const char *dirname)
+{
+ struct dirent *dent;
+
+ /* Give a generic message for AllocateDir failure, if caller didn't */
+ if (dir == NULL)
+ ereport(ERROR,
+ (errcode_for_file_access(),
+ errmsg("could not open directory \"%s\": %m",
+ dirname)));
+
+ errno = 0;
+ if ((dent = readdir(dir)) != NULL)
+ return dent;
+
+#ifdef WIN32
+
+ /*
+ * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
+ * released version
+ */
+ if (GetLastError() == ERROR_NO_MORE_FILES)
+ errno = 0;
+#endif
+
+ if (errno)
+ ereport(ERROR,
+ (errcode_for_file_access(),
+ errmsg("could not read directory \"%s\": %m",
+ dirname)));
+ return NULL;
+}
+
+/*
+ * Close a directory opened with AllocateDir.
+ *
+ * Note we do not check closedir's return value --- it is up to the caller
+ * to handle close errors.
+ */
+int
+FreeDir(DIR *dir)
{
int i;
- DO_DB(elog(DEBUG, "FreeFile: Allocated %d", numAllocatedFiles));
+ DO_DB(elog(LOG, "FreeDir: Allocated %d", numAllocatedDescs));
- /* Remove file from list of allocated files, if it's present */
- for (i = numAllocatedFiles; --i >= 0;)
+ /* Remove dir from list of allocated dirs, if it's present */
+ for (i = numAllocatedDescs; --i >= 0;)
{
- if (allocatedFiles[i] == file)
- {
- allocatedFiles[i] = allocatedFiles[--numAllocatedFiles];
- break;
- }
+ AllocateDesc *desc = &allocatedDescs[i];
+
+ if (desc->kind == AllocateDescDir && desc->desc.dir == dir)
+ return FreeDesc(desc);
}
- if (i < 0)
- elog(NOTICE, "FreeFile: file was not obtained from AllocateFile");
- fclose(file);
+ /* Only get here if someone passes us a dir not in allocatedDescs */
+ elog(WARNING, "dir passed to FreeDir was not obtained from AllocateDir");
+
+ return closedir(dir);
}
+
/*
* closeAllVfds
*
}
/*
- * AtEOXact_Files
+ * AtEOSubXact_Files
*
- * This routine is called during transaction commit or abort or backend
- * exit (it doesn't particularly care which). All still-open temporary-file
- * VFDs are closed, which also causes the underlying files to be deleted.
- * Furthermore, all "allocated" stdio files are closed.
+ * Take care of subtransaction commit/abort. At abort, we close temp files
+ * that the subtransaction may have opened. At commit, we reassign the
+ * files that were opened to the parent subtransaction.
+ */
+void
+AtEOSubXact_Files(bool isCommit, SubTransactionId mySubid,
+ SubTransactionId parentSubid)
+{
+ Index i;
+
+ if (SizeVfdCache > 0)
+ {
+ Assert(FileIsNotOpen(0)); /* Make sure ring not corrupted */
+ for (i = 1; i < SizeVfdCache; i++)
+ {
+ unsigned short fdstate = VfdCache[i].fdstate;
+
+ if ((fdstate & FD_XACT_TEMPORARY) &&
+ VfdCache[i].create_subid == mySubid)
+ {
+ if (isCommit)
+ VfdCache[i].create_subid = parentSubid;
+ else if (VfdCache[i].fileName != NULL)
+ FileClose(i);
+ }
+ }
+ }
+
+ for (i = 0; i < numAllocatedDescs; i++)
+ {
+ if (allocatedDescs[i].create_subid == mySubid)
+ {
+ if (isCommit)
+ allocatedDescs[i].create_subid = parentSubid;
+ else
+ {
+ /* have to recheck the item after FreeDesc (ugly) */
+ FreeDesc(&allocatedDescs[i--]);
+ }
+ }
+ }
+}
+
+/*
+ * AtEOXact_Files
*
- * This routine is not involved in fsync'ing non-temporary files at xact
- * commit; that is done by FileSync under control of the buffer manager.
- * During a commit, that is done *before* control gets here. If we still
- * have any needs-fsync bits set when we get here, we assume this is abort
- * and clear them.
+ * This routine is called during transaction commit or abort (it doesn't
+ * particularly care which). All still-open per-transaction temporary file
+ * VFDs are closed, which also causes the underlying files to be
+ * deleted. Furthermore, all "allocated" stdio files are closed.
*/
void
AtEOXact_Files(void)
+{
+ CleanupTempFiles(false);
+}
+
+/*
+ * AtProcExit_Files
+ *
+ * on_proc_exit hook to clean up temp files during backend shutdown.
+ * Here, we want to clean up *all* temp files including interXact ones.
+ */
+static void
+AtProcExit_Files(int code, Datum arg)
+{
+ CleanupTempFiles(true);
+}
+
+/*
+ * 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
+ * that's not the case, we are being called for transaction commit/abort
+ * and should only remove transaction-local temp files. In either case,
+ * also clean up "allocated" stdio files and dirs.
+ */
+static void
+CleanupTempFiles(bool isProcExit)
{
Index i;
Assert(FileIsNotOpen(0)); /* Make sure ring not corrupted */
for (i = 1; i < SizeVfdCache; i++)
{
- if ((VfdCache[i].fdstate & FD_TEMPORARY) &&
- VfdCache[i].fileName != NULL)
- FileClose(i);
- else
- VfdCache[i].fdstate &= ~FD_DIRTY;
+ unsigned short fdstate = VfdCache[i].fdstate;
+
+ if ((fdstate & FD_TEMPORARY) && VfdCache[i].fileName != NULL)
+ {
+ /*
+ * 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.
+ */
+ if (isProcExit || (fdstate & FD_XACT_TEMPORARY))
+ FileClose(i);
+ }
}
}
- while (numAllocatedFiles > 0)
- FreeFile(allocatedFiles[0]);
+ while (numAllocatedDescs > 0)
+ FreeDesc(&allocatedDescs[0]);
+}
+
+
+/*
+ * Remove temporary files left over from a prior postmaster session
+ *
+ * This should be called during postmaster startup. It will forcibly
+ * remove any leftover files created by OpenTemporaryFile.
+ *
+ * NOTE: we could, but don't, call this during a post-backend-crash restart
+ * cycle. The argument for not doing it is that someone might want to examine
+ * the temp files for debugging purposes. This does however mean that
+ * OpenTemporaryFile had better allow for collision with an existing temp
+ * file name.
+ */
+void
+RemovePgTempFiles(void)
+{
+ char temp_path[MAXPGPATH];
+ DIR *db_dir;
+ struct dirent *db_de;
+
+ /*
+ * Cycle through pgsql_tmp directories for all databases and remove old
+ * temp files.
+ */
+ db_dir = AllocateDir("base");
+
+ while ((db_de = ReadDir(db_dir, "base")) != NULL)
+ {
+ if (strcmp(db_de->d_name, ".") == 0 ||
+ strcmp(db_de->d_name, "..") == 0)
+ continue;
+
+ snprintf(temp_path, sizeof(temp_path), "base/%s/%s",
+ db_de->d_name, PG_TEMP_FILES_DIR);
+ RemovePgTempFilesInDir(temp_path);
+ }
+
+ FreeDir(db_dir);
/*
- * Reset the tempfile name counter to 0; not really necessary, but
- * helps keep the names from growing unreasonably long.
+ * In EXEC_BACKEND case there is a pgsql_tmp directory at the top level of
+ * DataDir as well.
*/
- tempFileCounter = 0;
+#ifdef EXEC_BACKEND
+ RemovePgTempFilesInDir(PG_TEMP_FILES_DIR);
+#endif
+}
+
+/* Process one pgsql_tmp directory for RemovePgTempFiles */
+static void
+RemovePgTempFilesInDir(const char *tmpdirname)
+{
+ DIR *temp_dir;
+ struct dirent *temp_de;
+ char rm_path[MAXPGPATH];
+
+ temp_dir = AllocateDir(tmpdirname);
+ if (temp_dir == NULL)
+ {
+ /* anything except ENOENT is fishy */
+ if (errno != ENOENT)
+ elog(LOG,
+ "could not open temporary-files directory \"%s\": %m",
+ tmpdirname);
+ return;
+ }
+
+ while ((temp_de = ReadDir(temp_dir, tmpdirname)) != NULL)
+ {
+ if (strcmp(temp_de->d_name, ".") == 0 ||
+ strcmp(temp_de->d_name, "..") == 0)
+ continue;
+
+ snprintf(rm_path, sizeof(rm_path), "%s/%s",
+ tmpdirname, temp_de->d_name);
+
+ if (strncmp(temp_de->d_name,
+ PG_TEMP_FILE_PREFIX,
+ strlen(PG_TEMP_FILE_PREFIX)) == 0)
+ unlink(rm_path); /* note we ignore any error */
+ else
+ elog(LOG,
+ "unexpected file found in temporary-files directory: \"%s\"",
+ rm_path);
+ }
+
+ FreeDir(temp_dir);
}
projects / postgresql / blobdiff