rdelaage
/
postgresql
mirror of https://git.postgresql.org/git/postgresql.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Remove durable_rename_excl() 

A previous commit replaced all the calls to this function with
durable_rename() as of dac1ff3, making it used nowhere in the tree.
Using it in extension code is also risky based on the issues described
in this previous commit, so let's remove it.  This makes possible the
removal of HAVE_WORKING_LINK.

Author: Nathan Bossart
Reviewed-by: Robert Haas, Kyotaro Horiguchi, Michael Paquier
Discussion: https://postgr.es/m/20220407182954.GA1231544@nathanxps13
This commit is contained in:
Michael Paquier 2022-07-05 12:54:25 +09:00
parent dac1ff3090
commit eb64ceac7e
3 changed files with 0 additions and 71 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

63
src/backend/storage/file/fd.c
View File

@ -807,69 +807,6 @@ durable_unlink(const char *fname, int elevel)
return 0;
}
/*
* durable_rename_excl -- rename a file in a durable manner.
*
* Similar to durable_rename(), except that this routine tries (but does not
* guarantee) not to overwrite the target file.
*
* Note that a crash in an unfortunate moment can leave you with two links to
* the target file.
*
* Log errors with the caller specified severity.
*
* On Windows, using a hard link followed by unlink() causes concurrency
* issues, while a simple rename() does not cause that, so be careful when
* changing the logic of this routine.
*
* Returns 0 if the operation succeeded, -1 otherwise. Note that errno is not
* valid upon return.
*/
int
durable_rename_excl(const char *oldfile, const char *newfile, int elevel)
{
/*
* Ensure that, if we crash directly after the rename/link, a file with
* valid contents is moved into place.
*/
if (fsync_fname_ext(oldfile, false, false, elevel) != 0)
return -1;
#ifdef HAVE_WORKING_LINK
if (link(oldfile, newfile) < 0)
{
ereport(elevel,
(errcode_for_file_access(),
errmsg("could not link file \"%s\" to \"%s\": %m",
oldfile, newfile)));
return -1;
}
unlink(oldfile);
#else
if (rename(oldfile, newfile) < 0)
{
ereport(elevel,
(errcode_for_file_access(),
errmsg("could not rename file \"%s\" to \"%s\": %m",
oldfile, newfile)));
return -1;
}
#endif
/*
* Make change persistent in case of an OS crash, both the new entry and
* its parent directory need to be flushed.
*/
if (fsync_fname_ext(newfile, false, false, elevel) != 0)
return -1;
/* Same for parent directory */
if (fsync_parent_path(newfile, elevel) != 0)
return -1;
return 0;
}
/*
* InitFileAccess --- initialize this module during backend startup
*

7
src/include/pg_config_manual.h
View File

@ -152,13 +152,6 @@
#define EXEC_BACKEND
#endif
/*
* Define this if your operating system supports link()
*/
#if !defined(WIN32) && !defined(__CYGWIN__)
#define HAVE_WORKING_LINK 1
#endif
/*
* USE_POSIX_FADVISE controls whether Postgres will attempt to use the
* posix_fadvise() kernel call. Usually the automatic configure tests are

1
src/include/storage/fd.h
View File

@ -187,7 +187,6 @@ extern void fsync_fname(const char *fname, bool isdir);
extern int fsync_fname_ext(const char *fname, bool isdir, bool ignore_perm, int elevel);
extern int durable_rename(const char *oldfile, const char *newfile, int loglevel);
extern int durable_unlink(const char *fname, int loglevel);
extern int durable_rename_excl(const char *oldfile, const char *newfile, int loglevel);
extern void SyncDataDirectory(void);
extern int data_sync_elevel(int elevel);