* fd.c
* Virtual file descriptor code.
*
- * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
+ * 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 1.100 2003/08/04 00:43:23 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/storage/file/fd.c,v 1.130 2006/10/04 00:29:57 momjian Exp $
*
* NOTES:
*
#include <sys/file.h>
#include <sys/param.h>
#include <sys/stat.h>
-#include <dirent.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"
-/* Filename components for OpenTemporaryFile */
-#define PG_TEMP_FILES_DIR "pgsql_tmp"
-#define PG_TEMP_FILE_PREFIX "pgsql_tmp"
-
-
/*
- * 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. And stdin/stdout/stderr count too. 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
/*
- * 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.
- *
- * I think 10 is an appropriate value so that's what it'll be
- * for now.
+ * If we have fewer than this many usable FDs after allowing for the reserved
+ * ones, choke.
*/
-#ifndef FD_MINFREE
-#define FD_MINFREE 10
-#endif
+#define FD_MINFREE 10
+
/*
- * A number of platforms return values for sysconf(_SC_OPEN_MAX) that are
- * far beyond what they can really support. This GUC parameter limits what
- * we will believe.
+ * 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.
+ *
+ * Note: the value of max_files_per_process is taken into account while
+ * setting this variable, and so need not be tested separately.
+ */
+static int max_safe_fds = 32; /* default if not changed */
+
/* Debugging.... */
{
signed short fd; /* current FD, or VFD_CLOSED if none */
unsigned short fdstate; /* bitflags for VFD's state */
+ 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 lruLessRecently;
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 session;
static void FreeVfd(File file);
static int FileAccess(File file);
-static File fileNameOpenFile(FileName fileName, int fileFlags, int fileMode);
-static char *filepath(const char *filename);
-static long pg_nofile(void);
-static void AtProcExit_Files(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);
/*
- * pg_fsync --- same as fsync except does nothing if enableFsync is off
+ * 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);
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
*
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
*
ereport(LOG,
(errcode(ERRCODE_INSUFFICIENT_RESOURCES),
- errmsg("out of file descriptors: %m; release and retry")));
+ 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;
-
- /* need do this calculation only once */
- if (no_files == 0)
- {
- /*
- * Ask the system what its files-per-process limit is.
- */
-#ifdef HAVE_SYSCONF
- no_files = sysconf(_SC_OPEN_MAX);
- if (no_files <= 0)
- {
-#ifdef NOFILE
- no_files = (long) NOFILE;
-#else
- no_files = (long) max_files_per_process;
-#endif
- elog(LOG, "sysconf(_SC_OPEN_MAX) failed; using %ld",
- no_files);
- }
-#else /* !HAVE_SYSCONF */
-#ifdef NOFILE
- no_files = (long) NOFILE;
-#else
- no_files = (long) max_files_per_process;
-#endif
-#endif /* HAVE_SYSCONF */
-
- /*
- * Some platforms return hopelessly optimistic values. Apply a
- * configurable upper limit.
- */
- if (no_files > (long) max_files_per_process)
- no_files = (long) max_files_per_process;
-
- /*
- * Make sure we have enough to get by after reserving some for LD.
- */
- if ((no_files - RESERVE_FOR_LD) < FD_MINFREE)
- ereport(FATAL,
- (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
- errmsg("insufficient file descriptors available to start backend"),
- errdetail("System allows %ld, we need at least %d.",
- no_files, RESERVE_FOR_LD + FD_MINFREE)));
-
- no_files -= RESERVE_FOR_LD;
- }
-
- return no_files;
-}
-
#if defined(FDDEBUG)
static void
/* close the file */
if (close(vfdP->fd))
- elog(LOG, "failed to close \"%s\": %m",
+ elog(ERROR, "failed to close \"%s\": %m",
vfdP->fileName);
--nfile;
DO_DB(_dump_lru());
}
+/* returns 0 on success, -1 on re-open failure (with errno set) */
static int
LruInsert(File file)
{
if (FileIsNotOpen(file))
{
- while (nfile + numAllocatedFiles >= pg_nofile())
+ while (nfile + numAllocatedDescs >= max_safe_fds)
{
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 (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(LOG, "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));
- 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 call to ensure temp files are dropped at
- * exit
- */
- on_proc_exit(AtProcExit_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;
VfdCache[0].nextFree = file;
}
-/* filepath()
- * Convert given pathname to absolute.
+/*
+ * make_database_relative()
+ * Prepend DatabasePath to the given file name.
*
* Result is a palloc'd string.
- *
- * (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.)
*/
static char *
-filepath(const char *filename)
+make_database_relative(const char *filename)
{
char *buf;
- /* Not an absolute path name? Then fill in with database path... */
- if (!is_absolute_path(filename))
- {
- buf = (char *) palloc(strlen(DatabasePath) + strlen(filename) + 2);
- sprintf(buf, "%s/%s", DatabasePath, filename);
- }
- else
- buf = pstrdup(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)
{
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);
}
#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 $PGDATA when this code is running).
+ */
+File
+PathNameOpenFile(FileName fileName, int fileFlags, int fileMode)
{
char *fnamecopy;
File file;
Vfd *vfdP;
- DO_DB(elog(LOG, "fileNameOpenFile: %s %x %o",
+ DO_DB(elog(LOG, "PathNameOpenFile: %s %x %o",
fileName, fileFlags, fileMode));
/*
file = AllocateVfd();
vfdP = &VfdCache[file];
- while (nfile + numAllocatedFiles >= pg_nofile())
+ while (nfile + numAllocatedDescs >= max_safe_fds)
{
if (!ReleaseLruFile())
break;
return -1;
}
++nfile;
- DO_DB(elog(LOG, "fileNameOpenFile: success %d",
+ DO_DB(elog(LOG, "PathNameOpenFile: success %d",
vfdP->fd));
Insert(file);
}
/*
- * open a file in the database directory ($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.
*
MyProcPid, tempFileCounter++);
/*
- * Open the file. Note: we don't use O_EXCL, in case there is an
- * orphaned temp file that can be reused.
+ * 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,
char *dirpath;
/*
- * We might need to create the pg_tempfiles subdirectory, if no
- * one has yet done so.
+ * 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.
+ * just did the same thing. If it doesn't work then we'll bomb out on
+ * the second create attempt, instead.
*/
- dirpath = filepath(PG_TEMP_FILES_DIR);
+ dirpath = make_database_relative(PG_TEMP_FILES_DIR);
mkdir(dirpath, S_IRWXU);
pfree(dirpath);
/* Mark it for deletion at EOXact */
if (!interXact)
+ {
VfdCache[file].fdstate |= FD_XACT_TEMPORARY;
+ VfdCache[file].create_subid = GetCurrentSubTransactionId();
+ }
return file;
}
/* close the file */
if (close(vfdP->fd))
- elog(LOG, "failed to close \"%s\": %m",
+ elog(ERROR, "failed to close \"%s\": %m",
vfdP->fileName);
--nfile;
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;
}
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 != amount && errno == 0)
errno = ENOSPC;
- if (returnCode > 0)
+ if (returnCode >= 0)
VfdCache[file].seekPos += returnCode;
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(LOG, "FileSeek: %d (%s) %ld %ld %d",
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, "invalid whence: %d", whence);
if (offset < 0)
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, "invalid whence: %d", whence);
DO_DB(elog(LOG, "FileTruncate %d (%s)",
file, VfdCache[file].fileName));
- FileAccess(file);
+ returnCode = FileAccess(file);
+ if (returnCode < 0)
+ return returnCode;
+
returnCode = ftruncate(VfdCache[file].fd, (size_t) offset);
return returnCode;
}
* Ideally this should be the *only* direct call of fopen() in the backend.
*/
FILE *
-AllocateFile(char *name, char *mode)
+AllocateFile(const char *name, const char *mode)
{
FILE *file;
- DO_DB(elog(LOG, "AllocateFile: Allocated %d", numAllocatedFiles));
+ DO_DB(elog(LOG, "AllocateFile: Allocated %d (%s)",
+ numAllocatedDescs, name));
- if (numAllocatedFiles >= MAX_ALLOCATED_FILES)
- elog(ERROR, "too many private FDs demanded");
+ /*
+ * 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");
TryAgain:
if ((file = fopen(name, mode)) != NULL)
{
- allocatedFiles[numAllocatedFiles] = file;
- numAllocatedFiles++;
- return file;
+ AllocateDesc *desc = &allocatedDescs[numAllocatedDescs];
+
+ desc->kind = AllocateDescFile;
+ desc->desc.file = file;
+ desc->create_subid = GetCurrentSubTransactionId();
+ numAllocatedDescs++;
+ return desc->desc.file;
}
if (errno == EMFILE || errno == ENFILE)
ereport(LOG,
(errcode(ERRCODE_INSUFFICIENT_RESOURCES),
- errmsg("out of file descriptors: %m; release and retry")));
+ errmsg("out of file descriptors: %m; release and retry")));
errno = 0;
if (ReleaseLruFile())
goto TryAgain;
errno = save_errno;
}
+ /*
+ * 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;
+
+ elog(LOG, "Windows fopen(\"%s\",\"%s\") failed: code %lu, errno %d",
+ name, mode, GetLastError(), save_errno);
+ errno = save_errno;
+ }
+#endif
+
return NULL;
}
-void
+/*
+ * Free an AllocateDesc of either type.
+ *
+ * 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 do not check fclose's return value --- it is up to the caller
+ * to handle close errors.
+ */
+int
FreeFile(FILE *file)
{
int i;
- DO_DB(elog(LOG, "FreeFile: Allocated %d", numAllocatedFiles));
+ DO_DB(elog(LOG, "FreeFile: Allocated %d", numAllocatedDescs));
/* Remove file from list of allocated files, if it's present */
- for (i = numAllocatedFiles; --i >= 0;)
+ for (i = numAllocatedDescs; --i >= 0;)
{
- if (allocatedFiles[i] == file)
- {
- numAllocatedFiles--;
- allocatedFiles[i] = allocatedFiles[numAllocatedFiles];
- break;
- }
+ AllocateDesc *desc = &allocatedDescs[i];
+
+ if (desc->kind == AllocateDescFile && desc->desc.file == file)
+ return FreeDesc(desc);
+ }
+
+ /* 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 <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 opendir() in the backend.
+ */
+DIR *
+AllocateDir(const char *dirname)
+{
+ DIR *dir;
+
+ DO_DB(elog(LOG, "AllocateDir: Allocated %d (%s)",
+ numAllocatedDescs, dirname));
+
+ /*
+ * 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 ((dir = opendir(dirname)) != NULL)
+ {
+ 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;
+
+ ereport(LOG,
+ (errcode(ERRCODE_INSUFFICIENT_RESOURCES),
+ errmsg("out of file descriptors: %m; release and retry")));
+ errno = 0;
+ if (ReleaseLruFile())
+ goto TryAgain;
+ errno = save_errno;
+ }
+
+ return NULL;
+}
+
+/*
+ * 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(LOG, "FreeDir: Allocated %d", numAllocatedDescs));
+
+ /* Remove dir from list of allocated dirs, if it's present */
+ for (i = numAllocatedDescs; --i >= 0;)
+ {
+ AllocateDesc *desc = &allocatedDescs[i];
+
+ if (desc->kind == AllocateDescDir && desc->desc.dir == dir)
+ return FreeDesc(desc);
}
- if (i < 0)
- elog(WARNING, "file passed to FreeFile 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
*
}
}
+/*
+ * AtEOSubXact_Files
+ *
+ * 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
*
* Here, we want to clean up *all* temp files including interXact ones.
*/
static void
-AtProcExit_Files(void)
+AtProcExit_Files(int code, Datum arg)
{
CleanupTempFiles(true);
}
* 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.
+ * also clean up "allocated" stdio files and dirs.
*/
static void
CleanupTempFiles(bool isProcExit)
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 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]);
}
void
RemovePgTempFiles(void)
{
- char db_path[MAXPGPATH];
char temp_path[MAXPGPATH];
- char rm_path[MAXPGPATH];
DIR *db_dir;
- DIR *temp_dir;
struct dirent *db_de;
- struct dirent *temp_de;
/*
- * Cycle through pg_tempfiles for all databases and remove old temp
- * files.
+ * Cycle through pgsql_tmp directories for all databases and remove old
+ * temp files.
*/
- snprintf(db_path, sizeof(db_path), "%s/base", DataDir);
- if ((db_dir = opendir(db_path)) != NULL)
+ db_dir = AllocateDir("base");
+
+ while ((db_de = ReadDir(db_dir, "base")) != NULL)
{
- while ((db_de = readdir(db_dir)) != NULL)
- {
- if (strcmp(db_de->d_name, ".") == 0 ||
- strcmp(db_de->d_name, "..") == 0)
- continue;
-
- snprintf(temp_path, sizeof(temp_path),
- "%s/%s/%s",
- db_path, db_de->d_name,
- PG_TEMP_FILES_DIR);
- if ((temp_dir = opendir(temp_path)) != NULL)
- {
- while ((temp_de = readdir(temp_dir)) != NULL)
- {
- if (strcmp(temp_de->d_name, ".") == 0 ||
- strcmp(temp_de->d_name, "..") == 0)
- continue;
-
- snprintf(rm_path, sizeof(temp_path),
- "%s/%s/%s/%s",
- db_path, db_de->d_name,
- PG_TEMP_FILES_DIR,
- temp_de->d_name);
-
- if (strncmp(temp_de->d_name,
- PG_TEMP_FILE_PREFIX,
- strlen(PG_TEMP_FILE_PREFIX)) == 0)
- unlink(rm_path);
- else
- elog(LOG,
- "unexpected file found in temporary-files directory: \"%s\"",
- rm_path);
- }
- closedir(temp_dir);
- }
- }
- closedir(db_dir);
+ 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);
+
+ /*
+ * In EXEC_BACKEND case there is a pgsql_tmp directory at the top level of
+ * DataDir as well.
+ */
+#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