diff options
| -rw-r--r-- | src/backend/access/transam/xact.c | 7 | ||||
| -rw-r--r-- | src/backend/libpq/be-fsstubs.c | 100 | ||||
| -rw-r--r-- | src/include/libpq/be-fsstubs.h | 4 |
3 files changed, 83 insertions, 28 deletions
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c index 000abbc7ecb..8453d8688c2 100644 --- a/src/backend/access/transam/xact.c +++ b/src/backend/access/transam/xact.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.36 1999/05/25 16:07:50 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.37 1999/05/31 22:53:59 tgl Exp $ * * NOTES * Transaction aborts can now occur two ways: @@ -156,8 +156,6 @@ #include <miscadmin.h> #include <commands/async.h> #include <commands/sequence.h> - -/* included for _lo_commit [PA, 7/17/98] */ #include <libpq/be-fsstubs.h> static void AbortTransaction(void); @@ -938,7 +936,7 @@ CommitTransaction() */ /* handle commit for large objects [ PA, 7/17/98 ] */ - _lo_commit(); + lo_commit(true); /* NOTIFY commit must also come before lower-level cleanup */ AtCommit_Notify(); @@ -1012,6 +1010,7 @@ AbortTransaction() * do abort processing * ---------------- */ + lo_commit(false); /* 'false' means it's abort */ UnlockBuffers(); AtAbort_Notify(); CloseSequences(); diff --git a/src/backend/libpq/be-fsstubs.c b/src/backend/libpq/be-fsstubs.c index bef974d8a5d..135eb03b2da 100644 --- a/src/backend/libpq/be-fsstubs.c +++ b/src/backend/libpq/be-fsstubs.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/libpq/be-fsstubs.c,v 1.33 1999/05/25 16:08:57 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/libpq/be-fsstubs.c,v 1.34 1999/05/31 22:53:57 tgl Exp $ * * NOTES * This should be moved to a more appropriate place. It is here @@ -15,10 +15,17 @@ * * Builtin functions for open/close/read/write operations on large objects. * - * These functions operate in the current portal variable context, which - * means the large object descriptors hang around between transactions and - * are not deallocated until explicitly closed, or until the portal is - * closed. + * These functions operate in a private GlobalMemoryContext, which means + * that large object descriptors hang around until we destroy the context. + * That happens in lo_commit(). It'd be possible to prolong the lifetime + * of the context so that LO FDs are good across transactions (for example, + * we could release the context only if we see that no FDs remain open). + * But we'd need additional state in order to do the right thing at the + * end of an aborted transaction. FDs opened during an aborted xact would + * still need to be closed, since they might not be pointing at valid + * relations at all. For now, we'll stick with the existing documented + * semantics of LO FDs: they're only good within a transaction. + * *------------------------------------------------------------------------- */ @@ -37,6 +44,7 @@ #include <utils/memutils.h> #include <lib/fstack.h> #include <utils/mcxt.h> +#include <catalog/pg_shadow.h> /* for superuser() */ #include <storage/fd.h> /* for O_ */ #include <storage/large_object.h> #include <libpq/be-fsstubs.h> @@ -91,6 +99,11 @@ lo_open(Oid lobjId, int mode) /* switch context back to orig. */ MemoryContextSwitchTo(currentContext); +#if FSDB + if (fd < 0) /* newLOfd couldn't find a slot */ + elog(NOTICE, "Out of space for large object FDs"); +#endif + return fd; } @@ -144,6 +157,8 @@ lo_read(int fd, char *buf, int len) elog(ERROR, "lo_read: invalid large obj descriptor (%d)", fd); return -3; } + + Assert(fscxt != NULL); currentContext = MemoryContextSwitchTo((MemoryContext) fscxt); status = inv_read(cookies[fd], buf, len); @@ -168,6 +183,8 @@ lo_write(int fd, char *buf, int len) elog(ERROR, "lo_write: invalid large obj descriptor (%d)", fd); return -3; } + + Assert(fscxt != NULL); currentContext = MemoryContextSwitchTo((MemoryContext) fscxt); status = inv_write(cookies[fd], buf, len); @@ -181,7 +198,7 @@ int lo_lseek(int fd, int offset, int whence) { MemoryContext currentContext; - int ret; + int status; if (fd < 0 || fd >= MAX_LOBJ_FDS) { @@ -194,13 +211,14 @@ lo_lseek(int fd, int offset, int whence) return -3; } + Assert(fscxt != NULL); currentContext = MemoryContextSwitchTo((MemoryContext) fscxt); - ret = inv_seek(cookies[fd], offset, whence); + status = inv_seek(cookies[fd], offset, whence); MemoryContextSwitchTo(currentContext); - return ret; + return status; } Oid @@ -246,12 +264,26 @@ lo_tell(int fd) elog(ERROR, "lo_tell: invalid large object descriptor (%d)", fd); return -3; } + + /* + * We assume we do not need to switch contexts for inv_tell. + * That is true for now, but is probably more than this module + * ought to assume... + */ return inv_tell(cookies[fd]); } int lo_unlink(Oid lobjId) { + /* + * inv_destroy does not need a context switch, indeed it doesn't + * touch any LO-specific data structures at all. (Again, that's + * probably more than this module ought to be assuming.) + * + * XXX there ought to be some code to clean up any open LOs that + * reference the specified relation... as is, they remain "open". + */ return inv_destroy(lobjId); } @@ -297,16 +329,23 @@ lo_import(text *filename) File fd; int nbytes, tmp; - char buf[BUFSIZE]; char fnamebuf[FNAME_BUFSIZE]; LargeObjectDesc *lobj; Oid lobjOid; + if (!superuser()) + elog(ERROR, "You must have Postgres superuser privilege to use " + "server-side lo_import().\n\tAnyone can use the " + "client-side lo_import() provided by libpq."); + /* * open the file to be read in */ - StrNCpy(fnamebuf, VARDATA(filename), VARSIZE(filename) - VARHDRSZ + 1); + nbytes = VARSIZE(filename) - VARHDRSZ + 1; + if (nbytes > FNAME_BUFSIZE) + nbytes = FNAME_BUFSIZE; + StrNCpy(fnamebuf, VARDATA(filename), nbytes); #ifndef __CYGWIN32__ fd = PathNameOpenFile(fnamebuf, O_RDONLY, 0666); #else @@ -314,7 +353,7 @@ lo_import(text *filename) #endif if (fd < 0) { /* error */ - elog(ERROR, "be_lo_import: can't open unix file \"%s\"\n", + elog(ERROR, "lo_import: can't open unix file \"%s\": %m", fnamebuf); } @@ -341,10 +380,8 @@ lo_import(text *filename) { tmp = inv_write(lobj, buf, nbytes); if (tmp < nbytes) - { elog(ERROR, "lo_import: error while reading \"%s\"", fnamebuf); - } } FileClose(fd); @@ -363,12 +400,16 @@ lo_export(Oid lobjId, text *filename) File fd; int nbytes, tmp; - char buf[BUFSIZE]; char fnamebuf[FNAME_BUFSIZE]; LargeObjectDesc *lobj; mode_t oumask; + if (!superuser()) + elog(ERROR, "You must have Postgres superuser privilege to use " + "server-side lo_export().\n\tAnyone can use the " + "client-side lo_export() provided by libpq."); + /* * open the inversion "object" */ @@ -378,9 +419,16 @@ lo_export(Oid lobjId, text *filename) /* * open the file to be written to + * + * Note: we reduce backend's normal 077 umask to the slightly + * friendlier 022. This code used to drop it all the way to 0, + * but creating world-writable export files doesn't seem wise. */ - StrNCpy(fnamebuf, VARDATA(filename), VARSIZE(filename) - VARHDRSZ + 1); - oumask = umask((mode_t) 0); + nbytes = VARSIZE(filename) - VARHDRSZ + 1; + if (nbytes > FNAME_BUFSIZE) + nbytes = FNAME_BUFSIZE; + StrNCpy(fnamebuf, VARDATA(filename), nbytes); + oumask = umask((mode_t) 0022); #ifndef __CYGWIN32__ fd = PathNameOpenFile(fnamebuf, O_CREAT | O_WRONLY | O_TRUNC, 0666); #else @@ -389,7 +437,7 @@ lo_export(Oid lobjId, text *filename) umask(oumask); if (fd < 0) { /* error */ - elog(ERROR, "lo_export: can't open unix file \"%s\"", + elog(ERROR, "lo_export: can't open unix file \"%s\": %m", fnamebuf); } @@ -400,10 +448,8 @@ lo_export(Oid lobjId, text *filename) { tmp = FileWrite(fd, buf, nbytes); if (tmp < nbytes) - { elog(ERROR, "lo_export: error while writing \"%s\"", fnamebuf); - } } inv_close(lobj); @@ -417,24 +463,34 @@ lo_export(Oid lobjId, text *filename) * prepares large objects for transaction commit [PA, 7/17/98] */ void -_lo_commit(void) +lo_commit(bool isCommit) { int i; MemoryContext currentContext; if (fscxt == NULL) - return; + return; /* no LO operations in this xact */ currentContext = MemoryContextSwitchTo((MemoryContext) fscxt); + /* Clean out still-open index scans (not necessary if aborting) + * and clear cookies array so that LO fds are no longer good. + */ for (i = 0; i < MAX_LOBJ_FDS; i++) { if (cookies[i] != NULL) - inv_cleanindex(cookies[i]); + { + if (isCommit) + inv_cleanindex(cookies[i]); + cookies[i] = NULL; + } } MemoryContextSwitchTo(currentContext); + /* Release the LO memory context to prevent permanent memory leaks. */ + GlobalMemoryDestroy(fscxt); + fscxt = NULL; } diff --git a/src/include/libpq/be-fsstubs.h b/src/include/libpq/be-fsstubs.h index c1d0054f28b..beaddbc0b3f 100644 --- a/src/include/libpq/be-fsstubs.h +++ b/src/include/libpq/be-fsstubs.h @@ -6,7 +6,7 @@ * * Copyright (c) 1994, Regents of the University of California * - * $Id: be-fsstubs.h,v 1.8 1999/02/13 23:21:34 momjian Exp $ + * $Id: be-fsstubs.h,v 1.9 1999/05/31 22:53:58 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -40,6 +40,6 @@ extern int lowrite(int fd, struct varlena * wbuf); /* * Added for buffer leak prevention [ Pascal André <andre@via.ecp.fr> ] */ -extern void _lo_commit(void); +extern void lo_commit(bool isCommit); #endif /* BE_FSSTUBS_H */ |