diff options
Diffstat (limited to 'src/port/open.c')
| -rw-r--r-- | src/port/open.c | 104 |
1 files changed, 56 insertions, 48 deletions
diff --git a/src/port/open.c b/src/port/open.c index 14c6debba91..7b52bd83c28 100644 --- a/src/port/open.c +++ b/src/port/open.c @@ -13,17 +13,20 @@ #ifdef WIN32 +#define UMDF_USING_NTSTATUS + #ifndef FRONTEND #include "postgres.h" #else #include "postgres_fe.h" #endif +#include "port/win32ntdll.h" + #include <fcntl.h> #include <assert.h> #include <sys/stat.h> - static int openFlagsToCreateFileFlags(int openFlags) { @@ -56,38 +59,25 @@ openFlagsToCreateFileFlags(int openFlags) } /* - * - file attribute setting, based on fileMode? + * Internal function used by pgwin32_open() and _pgstat64(). When + * backup_semantics is true, directories may be opened (for limited uses). On + * failure, INVALID_HANDLE_VALUE is returned and errno is set. */ -int -pgwin32_open(const char *fileName, int fileFlags,...) +HANDLE +pgwin32_open_handle(const char *fileName, int fileFlags, bool backup_semantics) { - int fd; - HANDLE h = INVALID_HANDLE_VALUE; + HANDLE h; SECURITY_ATTRIBUTES sa; int loops = 0; + if (initialize_ntdll() < 0) + return INVALID_HANDLE_VALUE; + /* Check that we can handle the request */ assert((fileFlags & ((O_RDONLY | O_WRONLY | O_RDWR) | O_APPEND | (O_RANDOM | O_SEQUENTIAL | O_TEMPORARY) | _O_SHORT_LIVED | O_DSYNC | O_DIRECT | (O_CREAT | O_TRUNC | O_EXCL) | (O_TEXT | O_BINARY))) == fileFlags); -#ifndef FRONTEND - Assert(pgwin32_signal_event != NULL); /* small chance of pg_usleep() */ -#endif - -#ifdef FRONTEND - - /* - * Since PostgreSQL 12, those concurrent-safe versions of open() and - * fopen() can be used by frontends, having as side-effect to switch the - * file-translation mode from O_TEXT to O_BINARY if none is specified. - * Caller may want to enforce the binary or text mode, but if nothing is - * defined make sure that the default mode maps with what versions older - * than 12 have been doing. - */ - if ((fileFlags & O_BINARY) == 0) - fileFlags |= O_TEXT; -#endif sa.nLength = sizeof(sa); sa.bInheritHandle = TRUE; @@ -102,6 +92,7 @@ pgwin32_open(const char *fileName, int fileFlags,...) &sa, openFlagsToCreateFileFlags(fileFlags), FILE_ATTRIBUTE_NORMAL | + (backup_semantics ? FILE_FLAG_BACKUP_SEMANTICS : 0) | ((fileFlags & O_RANDOM) ? FILE_FLAG_RANDOM_ACCESS : 0) | ((fileFlags & O_SEQUENTIAL) ? FILE_FLAG_SEQUENTIAL_SCAN : 0) | ((fileFlags & _O_SHORT_LIVED) ? FILE_ATTRIBUTE_TEMPORARY : 0) | @@ -140,38 +131,55 @@ pgwin32_open(const char *fileName, int fileFlags,...) /* * ERROR_ACCESS_DENIED is returned if the file is deleted but not yet * gone (Windows NT status code is STATUS_DELETE_PENDING). In that - * case we want to wait a bit and try again, giving up after 1 second - * (since this condition should never persist very long). However, - * there are other commonly-hit cases that return ERROR_ACCESS_DENIED, - * so care is needed. In particular that happens if we try to open a - * directory, or of course if there's an actual file-permissions - * problem. To distinguish these cases, try a stat(). In the - * delete-pending case, it will either also get STATUS_DELETE_PENDING, - * or it will see the file as gone and fail with ENOENT. In other - * cases it will usually succeed. The only somewhat-likely case where - * this coding will uselessly wait is if there's a permissions problem - * with a containing directory, which we hope will never happen in any - * performance-critical code paths. + * case, we'd better ask for the NT status too so we can translate it + * to a more Unix-like error. We hope that nothing clobbers the NT + * status in between the internal NtCreateFile() call and CreateFile() + * returning. + * + * If there's no O_CREAT flag, then we'll pretend the file is + * invisible. With O_CREAT, we have no choice but to report that + * there's a file in the way (which wouldn't happen on Unix). */ - if (err == ERROR_ACCESS_DENIED) + if (err == ERROR_ACCESS_DENIED && + pg_RtlGetLastNtStatus() == STATUS_DELETE_PENDING) { - if (loops < 10) - { - struct stat st; - - if (stat(fileName, &st) != 0) - { - pg_usleep(100000); - loops++; - continue; - } - } + if (fileFlags & O_CREAT) + err = ERROR_FILE_EXISTS; + else + err = ERROR_FILE_NOT_FOUND; } _dosmaperr(err); - return -1; + return INVALID_HANDLE_VALUE; } + return h; +} + +int +pgwin32_open(const char *fileName, int fileFlags,...) +{ + HANDLE h; + int fd; + + h = pgwin32_open_handle(fileName, fileFlags, false); + if (h == INVALID_HANDLE_VALUE) + return -1; + +#ifdef FRONTEND + + /* + * Since PostgreSQL 12, those concurrent-safe versions of open() and + * fopen() can be used by frontends, having as side-effect to switch the + * file-translation mode from O_TEXT to O_BINARY if none is specified. + * Caller may want to enforce the binary or text mode, but if nothing is + * defined make sure that the default mode maps with what versions older + * than 12 have been doing. + */ + if ((fileFlags & O_BINARY) == 0) + fileFlags |= O_TEXT; +#endif + /* _open_osfhandle will, on error, set errno accordingly */ if ((fd = _open_osfhandle((intptr_t) h, fileFlags & O_APPEND)) < 0) CloseHandle(h); /* will not affect errno */ |