/* Process one per-dbspace directory for ResetUnloggedRelations */
static void
ResetUnloggedRelationsInDbspaceDir(const char *dbspacedirname, int op)
{
DIR *dbspace_dir;
struct dirent *de;
char rm_path[MAXPGPATH];
/* Caller must specify at least one operation. */
Assert((op & (UNLOGGED_RELATION_CLEANUP | UNLOGGED_RELATION_INIT)) != 0);
/*
* Cleanup is a two-pass operation. First, we go through and identify all
* the files with init forks. Then, we go through again and nuke
* everything with the same OID except the init fork.
*/
if ((op & UNLOGGED_RELATION_CLEANUP) != 0)
{
HTAB *hash = NULL;
HASHCTL ctl;
/* Open the directory. */
dbspace_dir = AllocateDir(dbspacedirname);
if (dbspace_dir == NULL)
{
elog(LOG,
"could not open dbspace directory \"%s\": %m",
dbspacedirname);
return;
}
/*
* It's possible that someone could create a ton of unlogged relations
* in the same database & tablespace, so we'd better use a hash table
* rather than an array or linked list to keep track of which files
* need to be reset. Otherwise, this cleanup operation would be
* O(n^2).
*/
ctl.keysize = sizeof(unlogged_relation_entry);
ctl.entrysize = sizeof(unlogged_relation_entry);
hash = hash_create("unlogged hash", 32, &ctl, HASH_ELEM);
/* Scan the directory. */
while ((de = ReadDir(dbspace_dir, dbspacedirname)) != NULL)
{
ForkNumber forkNum;
int oidchars;
unlogged_relation_entry ent;
/* Skip anything that doesn't look like a relation data file. */
if (!parse_filename_for_nontemp_relation(de->d_name, &oidchars,
&forkNum))
continue;
/* Also skip it unless this is the init fork. */
if (forkNum != INIT_FORKNUM)
continue;
/*
* Put the OID portion of the name into the hash table, if it
* isn't already.
*/
memset(ent.oid, 0, sizeof(ent.oid));
memcpy(ent.oid, de->d_name, oidchars);
hash_search(hash, &ent, HASH_ENTER, NULL);
}
/* Done with the first pass. */
FreeDir(dbspace_dir);
/*
* If we didn't find any init forks, there's no point in continuing;
* we can bail out now.
*/
if (hash_get_num_entries(hash) == 0)
{
hash_destroy(hash);
return;
}
/*
* Now, make a second pass and remove anything that matches. First,
* reopen the directory.
*/
dbspace_dir = AllocateDir(dbspacedirname);
if (dbspace_dir == NULL)
{
elog(LOG,
"could not open dbspace directory \"%s\": %m",
dbspacedirname);
hash_destroy(hash);
return;
}
/* Scan the directory. */
while ((de = ReadDir(dbspace_dir, dbspacedirname)) != NULL)
{
ForkNumber forkNum;
int oidchars;
bool found;
unlogged_relation_entry ent;
/* Skip anything that doesn't look like a relation data file. */
if (!parse_filename_for_nontemp_relation(de->d_name, &oidchars,
&forkNum))
continue;
/* We never remove the init fork. */
if (forkNum == INIT_FORKNUM)
continue;
/*
* See whether the OID portion of the name shows up in the hash
* table.
*/
memset(ent.oid, 0, sizeof(ent.oid));
memcpy(ent.oid, de->d_name, oidchars);
hash_search(hash, &ent, HASH_FIND, &found);
/* If so, nuke it! */
if (found)
{
snprintf(rm_path, sizeof(rm_path), "%s/%s",
dbspacedirname, de->d_name);
/*
* It's tempting to actually throw an error here, but since
* this code gets run during database startup, that could
* result in the database failing to start. (XXX Should we do
* it anyway?)
*/
if (unlink(rm_path))
elog(LOG, "could not unlink file \"%s\": %m", rm_path);
else
elog(DEBUG2, "unlinked file \"%s\"", rm_path);
}
}
/* Cleanup is complete. */
FreeDir(dbspace_dir);
hash_destroy(hash);
}
/*
* Initialization happens after cleanup is complete: we copy each init
* fork file to the corresponding main fork file. Note that if we are
* asked to do both cleanup and init, we may never get here: if the
* cleanup code determines that there are no init forks in this dbspace,
* it will return before we get to this point.
*/
if ((op & UNLOGGED_RELATION_INIT) != 0)
{
/* Open the directory. */
dbspace_dir = AllocateDir(dbspacedirname);
if (dbspace_dir == NULL)
{
/* we just saw this directory, so it really ought to be there */
elog(LOG,
"could not open dbspace directory \"%s\": %m",
dbspacedirname);
return;
}
/* Scan the directory. */
while ((de = ReadDir(dbspace_dir, dbspacedirname)) != NULL)
{
ForkNumber forkNum;
int oidchars;
char oidbuf[OIDCHARS + 1];
char srcpath[MAXPGPATH];
char dstpath[MAXPGPATH];
/* Skip anything that doesn't look like a relation data file. */
if (!parse_filename_for_nontemp_relation(de->d_name, &oidchars,
&forkNum))
continue;
/* Also skip it unless this is the init fork. */
if (forkNum != INIT_FORKNUM)
continue;
/* Construct source pathname. */
snprintf(srcpath, sizeof(srcpath), "%s/%s",
dbspacedirname, de->d_name);
/* Construct destination pathname. */
memcpy(oidbuf, de->d_name, oidchars);
oidbuf[oidchars] = '\0';
snprintf(dstpath, sizeof(dstpath), "%s/%s%s",
dbspacedirname, oidbuf, de->d_name + oidchars + 1 +
strlen(forkNames[INIT_FORKNUM]));
/* OK, we're ready to perform the actual copy. */
elog(DEBUG2, "copying %s to %s", srcpath, dstpath);
copy_file(srcpath, dstpath);
}
/* Done with the first pass. */
FreeDir(dbspace_dir);
}
}
/*
* Process one per-dbspace directory for ResetUnloggedRelations
*/
static void
ResetUnloggedRelationsInDbspaceDir(const char *dbspacedirname, int op)
{
DIR *dbspace_dir;
struct dirent *de;
char rm_path[MAXPGPATH * 2];
/* Caller must specify at least one operation. */
Assert((op & (UNLOGGED_RELATION_CLEANUP | UNLOGGED_RELATION_INIT)) != 0);
/*
* Cleanup is a two-pass operation. First, we go through and identify all
* the files with init forks. Then, we go through again and nuke
* everything with the same OID except the init fork.
*/
if ((op & UNLOGGED_RELATION_CLEANUP) != 0)
{
HTAB *hash;
HASHCTL ctl;
/*
* It's possible that someone could create a ton of unlogged relations
* in the same database & tablespace, so we'd better use a hash table
* rather than an array or linked list to keep track of which files
* need to be reset. Otherwise, this cleanup operation would be
* O(n^2).
*/
memset(&ctl, 0, sizeof(ctl));
ctl.keysize = sizeof(unlogged_relation_entry);
ctl.entrysize = sizeof(unlogged_relation_entry);
hash = hash_create("unlogged hash", 32, &ctl, HASH_ELEM);
/* Scan the directory. */
dbspace_dir = AllocateDir(dbspacedirname);
while ((de = ReadDir(dbspace_dir, dbspacedirname)) != NULL)
{
ForkNumber forkNum;
int oidchars;
unlogged_relation_entry ent;
/* Skip anything that doesn't look like a relation data file. */
if (!parse_filename_for_nontemp_relation(de->d_name, &oidchars,
&forkNum))
continue;
/* Also skip it unless this is the init fork. */
if (forkNum != INIT_FORKNUM)
continue;
/*
* Put the OID portion of the name into the hash table, if it
* isn't already.
*/
memset(ent.oid, 0, sizeof(ent.oid));
memcpy(ent.oid, de->d_name, oidchars);
hash_search(hash, &ent, HASH_ENTER, NULL);
}
/* Done with the first pass. */
FreeDir(dbspace_dir);
/*
* If we didn't find any init forks, there's no point in continuing;
* we can bail out now.
*/
if (hash_get_num_entries(hash) == 0)
{
hash_destroy(hash);
return;
}
/*
* Now, make a second pass and remove anything that matches.
*/
dbspace_dir = AllocateDir(dbspacedirname);
while ((de = ReadDir(dbspace_dir, dbspacedirname)) != NULL)
{
ForkNumber forkNum;
int oidchars;
bool found;
unlogged_relation_entry ent;
/* Skip anything that doesn't look like a relation data file. */
if (!parse_filename_for_nontemp_relation(de->d_name, &oidchars,
&forkNum))
continue;
/* We never remove the init fork. */
if (forkNum == INIT_FORKNUM)
continue;
/*
* See whether the OID portion of the name shows up in the hash
* table.
*/
memset(ent.oid, 0, sizeof(ent.oid));
memcpy(ent.oid, de->d_name, oidchars);
hash_search(hash, &ent, HASH_FIND, &found);
/* If so, nuke it! */
if (found)
{
snprintf(rm_path, sizeof(rm_path), "%s/%s",
dbspacedirname, de->d_name);
if (unlink(rm_path) < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not remove file \"%s\": %m",
rm_path)));
else
elog(DEBUG2, "unlinked file \"%s\"", rm_path);
}
}
/* Cleanup is complete. */
FreeDir(dbspace_dir);
hash_destroy(hash);
}
/*
* Initialization happens after cleanup is complete: we copy each init
* fork file to the corresponding main fork file. Note that if we are
* asked to do both cleanup and init, we may never get here: if the
* cleanup code determines that there are no init forks in this dbspace,
* it will return before we get to this point.
*/
if ((op & UNLOGGED_RELATION_INIT) != 0)
{
/* Scan the directory. */
dbspace_dir = AllocateDir(dbspacedirname);
while ((de = ReadDir(dbspace_dir, dbspacedirname)) != NULL)
{
ForkNumber forkNum;
int oidchars;
char oidbuf[OIDCHARS + 1];
char srcpath[MAXPGPATH * 2];
char dstpath[MAXPGPATH];
/* Skip anything that doesn't look like a relation data file. */
if (!parse_filename_for_nontemp_relation(de->d_name, &oidchars,
&forkNum))
continue;
/* Also skip it unless this is the init fork. */
if (forkNum != INIT_FORKNUM)
continue;
/* Construct source pathname. */
snprintf(srcpath, sizeof(srcpath), "%s/%s",
dbspacedirname, de->d_name);
/* Construct destination pathname. */
memcpy(oidbuf, de->d_name, oidchars);
oidbuf[oidchars] = '\0';
snprintf(dstpath, sizeof(dstpath), "%s/%s%s",
dbspacedirname, oidbuf, de->d_name + oidchars + 1 +
strlen(forkNames[INIT_FORKNUM]));
/* OK, we're ready to perform the actual copy. */
elog(DEBUG2, "copying %s to %s", srcpath, dstpath);
copy_file(srcpath, dstpath);
}
FreeDir(dbspace_dir);
/*
* copy_file() above has already called pg_flush_data() on the files
* it created. Now we need to fsync those files, because a checkpoint
* won't do it for us while we're in recovery. We do this in a
* separate pass to allow the kernel to perform all the flushes
* (especially the metadata ones) at once.
*/
dbspace_dir = AllocateDir(dbspacedirname);
while ((de = ReadDir(dbspace_dir, dbspacedirname)) != NULL)
{
ForkNumber forkNum;
int oidchars;
char oidbuf[OIDCHARS + 1];
char mainpath[MAXPGPATH];
/* Skip anything that doesn't look like a relation data file. */
if (!parse_filename_for_nontemp_relation(de->d_name, &oidchars,
&forkNum))
continue;
/* Also skip it unless this is the init fork. */
if (forkNum != INIT_FORKNUM)
continue;
/* Construct main fork pathname. */
memcpy(oidbuf, de->d_name, oidchars);
oidbuf[oidchars] = '\0';
snprintf(mainpath, sizeof(mainpath), "%s/%s%s",
dbspacedirname, oidbuf, de->d_name + oidchars + 1 +
strlen(forkNames[INIT_FORKNUM]));
fsync_fname(mainpath, false);
}
FreeDir(dbspace_dir);
/*
* Lastly, fsync the database directory itself, ensuring the
* filesystem remembers the file creations and deletions we've done.
* We don't bother with this during a call that does only
* UNLOGGED_RELATION_CLEANUP, because if recovery crashes before we
* get to doing UNLOGGED_RELATION_INIT, we'll redo the cleanup step
* too at the next startup attempt.
*/
fsync_fname(dbspacedirname, true);
}
}
