Header And Logo
|
#include "postgres.h"#include <unistd.h>#include <fcntl.h>#include <sys/file.h>#include "miscadmin.h"#include "access/xlog.h"#include "catalog/catalog.h"#include "common/relpath.h"#include "portability/instr_time.h"#include "postmaster/bgwriter.h"#include "storage/fd.h"#include "storage/bufmgr.h"#include "storage/relfilenode.h"#include "storage/smgr.h"#include "utils/hsearch.h"#include "utils/memutils.h"#include "pg_trace.h"
Go to the source code of this file.
| #define FILE_POSSIBLY_DELETED | ( | err | ) | ((err) == ENOENT) |
Definition at line 66 of file md.c.
Referenced by _mdfd_getseg(), mdopen(), and mdsync().
| #define FORGET_DATABASE_FSYNC (InvalidBlockNumber-1) |
Definition at line 55 of file md.c.
Referenced by ForgetDatabaseFsyncRequests(), and RememberFsyncRequest().
| #define FORGET_RELATION_FSYNC (InvalidBlockNumber) |
Definition at line 54 of file md.c.
Referenced by ForgetRelationFsyncRequests(), and RememberFsyncRequest().
| #define UNLINK_RELATION_REQUEST (InvalidBlockNumber-2) |
Definition at line 56 of file md.c.
Referenced by register_unlink(), and RememberFsyncRequest().
| enum ExtensionBehavior |
Definition at line 166 of file md.c.
{
EXTENSION_FAIL, /* ereport if segment not present */
EXTENSION_RETURN_NULL, /* return NULL if not present */
EXTENSION_CREATE /* create new segments as needed */
} ExtensionBehavior;
| static MdfdVec * _fdvec_alloc | ( | void | ) | [static] |
Definition at line 1633 of file md.c.
References MemoryContextAlloc().
Referenced by _mdfd_openseg(), mdcreate(), and mdopen().
{
return (MdfdVec *) MemoryContextAlloc(MdCxt, sizeof(MdfdVec));
}
| static MdfdVec * _mdfd_getseg | ( | SMgrRelation | reln, | |
| ForkNumber | forkno, | |||
| BlockNumber | blkno, | |||
| bool | skipFsync, | |||
| ExtensionBehavior | behavior | |||
| ) | [static] |
Definition at line 1707 of file md.c.
References _mdfd_openseg(), _mdfd_segpath(), _mdnblocks(), Assert, ereport, errcode_for_file_access(), errmsg(), ERROR, EXTENSION_CREATE, EXTENSION_RETURN_NULL, FILE_POSSIBLY_DELETED, InRecovery, mdextend(), _MdfdVec::mdfd_chain, _MdfdVec::mdfd_segno, mdopen(), NULL, palloc0(), and pfree().
Referenced by mdextend(), mdprefetch(), mdread(), mdsync(), and mdwrite().
{
MdfdVec *v = mdopen(reln, forknum, behavior);
BlockNumber targetseg;
BlockNumber nextsegno;
if (!v)
return NULL; /* only possible if EXTENSION_RETURN_NULL */
targetseg = blkno / ((BlockNumber) RELSEG_SIZE);
for (nextsegno = 1; nextsegno <= targetseg; nextsegno++)
{
Assert(nextsegno == v->mdfd_segno + 1);
if (v->mdfd_chain == NULL)
{
/*
* Normally we will create new segments only if authorized by the
* caller (i.e., we are doing mdextend()). But when doing WAL
* recovery, create segments anyway; this allows cases such as
* replaying WAL data that has a write into a high-numbered
* segment of a relation that was later deleted. We want to go
* ahead and create the segments so we can finish out the replay.
*
* We have to maintain the invariant that segments before the last
* active segment are of size RELSEG_SIZE; therefore, pad them out
* with zeroes if needed. (This only matters if caller is
* extending the relation discontiguously, but that can happen in
* hash indexes.)
*/
if (behavior == EXTENSION_CREATE || InRecovery)
{
if (_mdnblocks(reln, forknum, v) < RELSEG_SIZE)
{
char *zerobuf = palloc0(BLCKSZ);
mdextend(reln, forknum,
nextsegno * ((BlockNumber) RELSEG_SIZE) - 1,
zerobuf, skipFsync);
pfree(zerobuf);
}
v->mdfd_chain = _mdfd_openseg(reln, forknum, +nextsegno, O_CREAT);
}
else
{
/* We won't create segment if not existent */
v->mdfd_chain = _mdfd_openseg(reln, forknum, nextsegno, 0);
}
if (v->mdfd_chain == NULL)
{
if (behavior == EXTENSION_RETURN_NULL &&
FILE_POSSIBLY_DELETED(errno))
return NULL;
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open file \"%s\" (target block %u): %m",
_mdfd_segpath(reln, forknum, nextsegno),
blkno)));
}
}
v = v->mdfd_chain;
}
return v;
}
| static MdfdVec * _mdfd_openseg | ( | SMgrRelation | reln, | |
| ForkNumber | forkno, | |||
| BlockNumber | segno, | |||
| int | oflags | |||
| ) | [static] |
Definition at line 1668 of file md.c.
References _fdvec_alloc(), _mdfd_segpath(), _mdnblocks(), Assert, _MdfdVec::mdfd_chain, _MdfdVec::mdfd_segno, _MdfdVec::mdfd_vfd, PathNameOpenFile(), pfree(), and PG_BINARY.
Referenced by _mdfd_getseg(), and mdnblocks().
{
MdfdVec *v;
int fd;
char *fullpath;
fullpath = _mdfd_segpath(reln, forknum, segno);
/* open the file */
fd = PathNameOpenFile(fullpath, O_RDWR | PG_BINARY | oflags, 0600);
pfree(fullpath);
if (fd < 0)
return NULL;
/* allocate an mdfdvec entry for it */
v = _fdvec_alloc();
/* fill the entry */
v->mdfd_vfd = fd;
v->mdfd_segno = segno;
v->mdfd_chain = NULL;
Assert(_mdnblocks(reln, forknum, v) <= ((BlockNumber) RELSEG_SIZE));
/* all done */
return v;
}
| static char * _mdfd_segpath | ( | SMgrRelation | reln, | |
| ForkNumber | forknum, | |||
| BlockNumber | segno | |||
| ) | [static] |
Definition at line 1643 of file md.c.
References palloc(), pfree(), relpath, and SMgrRelationData::smgr_rnode.
Referenced by _mdfd_getseg(), _mdfd_openseg(), mdnblocks(), and mdsync().
{
char *path,
*fullpath;
path = relpath(reln->smgr_rnode, forknum);
if (segno > 0)
{
/* be sure we have enough space for the '.segno' */
fullpath = (char *) palloc(strlen(path) + 12);
sprintf(fullpath, "%s.%u", path, segno);
pfree(path);
}
else
fullpath = path;
return fullpath;
}
| static BlockNumber _mdnblocks | ( | SMgrRelation | reln, | |
| ForkNumber | forknum, | |||
| MdfdVec * | seg | |||
| ) | [static] |
Definition at line 1777 of file md.c.
References ereport, errcode_for_file_access(), errmsg(), ERROR, FilePathName(), FileSeek(), and _MdfdVec::mdfd_vfd.
Referenced by _mdfd_getseg(), _mdfd_openseg(), mdextend(), mdnblocks(), and mdopen().
{
off_t len;
len = FileSeek(seg->mdfd_vfd, 0L, SEEK_END);
if (len < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not seek to end of file \"%s\": %m",
FilePathName(seg->mdfd_vfd))));
/* note that this calculation will ignore any partial block at EOF */
return (BlockNumber) (len / BLCKSZ);
}
| void ForgetDatabaseFsyncRequests | ( | Oid | dbid | ) |
Definition at line 1606 of file md.c.
References RelFileNode::dbNode, FORGET_DATABASE_FSYNC, ForwardFsyncRequest(), InvalidForkNumber, IsUnderPostmaster, pg_usleep(), RelFileNode::relNode, RememberFsyncRequest(), and RelFileNode::spcNode.
Referenced by dbase_redo(), and dropdb().
{
RelFileNode rnode;
rnode.dbNode = dbid;
rnode.spcNode = 0;
rnode.relNode = 0;
if (pendingOpsTable)
{
/* standalone backend or startup process: fsync state is local */
RememberFsyncRequest(rnode, InvalidForkNumber, FORGET_DATABASE_FSYNC);
}
else if (IsUnderPostmaster)
{
/* see notes in ForgetRelationFsyncRequests */
while (!ForwardFsyncRequest(rnode, InvalidForkNumber,
FORGET_DATABASE_FSYNC))
pg_usleep(10000L); /* 10 msec seems a good number */
}
}
| void ForgetRelationFsyncRequests | ( | RelFileNode | rnode, | |
| ForkNumber | forknum | |||
| ) |
Definition at line 1573 of file md.c.
References FORGET_RELATION_FSYNC, ForwardFsyncRequest(), IsUnderPostmaster, pg_usleep(), and RememberFsyncRequest().
Referenced by mdunlink().
{
if (pendingOpsTable)
{
/* standalone backend or startup process: fsync state is local */
RememberFsyncRequest(rnode, forknum, FORGET_RELATION_FSYNC);
}
else if (IsUnderPostmaster)
{
/*
* Notify the checkpointer about it. If we fail to queue the cancel
* message, we have to sleep and try again ... ugly, but hopefully
* won't happen often.
*
* XXX should we CHECK_FOR_INTERRUPTS in this loop? Escaping with an
* error would leave the no-longer-used file still present on disk,
* which would be bad, so I'm inclined to assume that the checkpointer
* will always empty the queue soon.
*/
while (!ForwardFsyncRequest(rnode, forknum, FORGET_RELATION_FSYNC))
pg_usleep(10000L); /* 10 msec seems a good number */
/*
* Note we don't wait for the checkpointer to actually absorb the
* cancel message; see mdsync() for the implications.
*/
}
}
| void mdclose | ( | SMgrRelation | reln, | |
| ForkNumber | forknum | |||
| ) |
Definition at line 607 of file md.c.
References FileClose(), SMgrRelationData::md_fd, _MdfdVec::mdfd_chain, _MdfdVec::mdfd_vfd, NULL, and pfree().
Referenced by mdexists().
{
MdfdVec *v = reln->md_fd[forknum];
/* No work if already closed */
if (v == NULL)
return;
reln->md_fd[forknum] = NULL; /* prevent dangling pointer after error */
while (v != NULL)
{
MdfdVec *ov = v;
/* if not closed already */
if (v->mdfd_vfd >= 0)
FileClose(v->mdfd_vfd);
/* Now free vector */
v = v->mdfd_chain;
pfree(ov);
}
}
| void mdcreate | ( | SMgrRelation | reln, | |
| ForkNumber | forkNum, | |||
| bool | isRedo | |||
| ) |
Definition at line 273 of file md.c.
References _fdvec_alloc(), Assert, ereport, errcode_for_file_access(), errmsg(), ERROR, IsBootstrapProcessingMode, SMgrRelationData::md_fd, _MdfdVec::mdfd_chain, _MdfdVec::mdfd_segno, _MdfdVec::mdfd_vfd, NULL, PathNameOpenFile(), pfree(), PG_BINARY, relpath, and SMgrRelationData::smgr_rnode.
{
char *path;
File fd;
if (isRedo && reln->md_fd[forkNum] != NULL)
return; /* created and opened already... */
Assert(reln->md_fd[forkNum] == NULL);
path = relpath(reln->smgr_rnode, forkNum);
fd = PathNameOpenFile(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY, 0600);
if (fd < 0)
{
int save_errno = errno;
/*
* During bootstrap, there are cases where a system relation will be
* accessed (by internal backend processes) before the bootstrap
* script nominally creates it. Therefore, allow the file to exist
* already, even if isRedo is not set. (See also mdopen)
*/
if (isRedo || IsBootstrapProcessingMode())
fd = PathNameOpenFile(path, O_RDWR | PG_BINARY, 0600);
if (fd < 0)
{
/* be sure to report the error reported by create, not open */
errno = save_errno;
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not create file \"%s\": %m", path)));
}
}
pfree(path);
reln->md_fd[forkNum] = _fdvec_alloc();
reln->md_fd[forkNum]->mdfd_vfd = fd;
reln->md_fd[forkNum]->mdfd_segno = 0;
reln->md_fd[forkNum]->mdfd_chain = NULL;
}
| bool mdexists | ( | SMgrRelation | reln, | |
| ForkNumber | forkNum | |||
| ) |
Definition at line 256 of file md.c.
References EXTENSION_RETURN_NULL, mdclose(), mdopen(), and NULL.
{
/*
* Close it first, to ensure that we notice if the fork has been unlinked
* since we opened it.
*/
mdclose(reln, forkNum);
return (mdopen(reln, forkNum, EXTENSION_RETURN_NULL) != NULL);
}
| void mdextend | ( | SMgrRelation | reln, | |
| ForkNumber | forknum, | |||
| BlockNumber | blocknum, | |||
| char * | buffer, | |||
| bool | skipFsync | |||
| ) |
Definition at line 474 of file md.c.
References _mdfd_getseg(), _mdnblocks(), Assert, ereport, errcode(), errcode_for_file_access(), errhint(), errmsg(), ERROR, EXTENSION_CREATE, FilePathName(), FileSeek(), FileWrite(), InvalidBlockNumber, _MdfdVec::mdfd_vfd, mdnblocks(), register_dirty_segment(), relpath, SMgrRelationData::smgr_rnode, and SmgrIsTemp.
Referenced by _mdfd_getseg().
{
off_t seekpos;
int nbytes;
MdfdVec *v;
/* This assert is too expensive to have on normally ... */
#ifdef CHECK_WRITE_VS_EXTEND
Assert(blocknum >= mdnblocks(reln, forknum));
#endif
/*
* If a relation manages to grow to 2^32-1 blocks, refuse to extend it any
* more --- we mustn't create a block whose number actually is
* InvalidBlockNumber.
*/
if (blocknum == InvalidBlockNumber)
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("cannot extend file \"%s\" beyond %u blocks",
relpath(reln->smgr_rnode, forknum),
InvalidBlockNumber)));
v = _mdfd_getseg(reln, forknum, blocknum, skipFsync, EXTENSION_CREATE);
seekpos = (off_t) BLCKSZ *(blocknum % ((BlockNumber) RELSEG_SIZE));
Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
/*
* Note: because caller usually obtained blocknum by calling mdnblocks,
* which did a seek(SEEK_END), this seek is often redundant and will be
* optimized away by fd.c. It's not redundant, however, if there is a
* partial page at the end of the file. In that case we want to try to
* overwrite the partial page with a full page. It's also not redundant
* if bufmgr.c had to dump another buffer of the same file to make room
* for the new page's buffer.
*/
if (FileSeek(v->mdfd_vfd, seekpos, SEEK_SET) != seekpos)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not seek to block %u in file \"%s\": %m",
blocknum, FilePathName(v->mdfd_vfd))));
if ((nbytes = FileWrite(v->mdfd_vfd, buffer, BLCKSZ)) != BLCKSZ)
{
if (nbytes < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not extend file \"%s\": %m",
FilePathName(v->mdfd_vfd)),
errhint("Check free disk space.")));
/* short write: complain appropriately */
ereport(ERROR,
(errcode(ERRCODE_DISK_FULL),
errmsg("could not extend file \"%s\": wrote only %d of %d bytes at block %u",
FilePathName(v->mdfd_vfd),
nbytes, BLCKSZ, blocknum),
errhint("Check free disk space.")));
}
if (!skipFsync && !SmgrIsTemp(reln))
register_dirty_segment(reln, forknum, v);
Assert(_mdnblocks(reln, forknum, v) <= ((BlockNumber) RELSEG_SIZE));
}
| void mdimmedsync | ( | SMgrRelation | reln, | |
| ForkNumber | forknum | |||
| ) |
Definition at line 950 of file md.c.
References ereport, errcode_for_file_access(), errmsg(), ERROR, EXTENSION_FAIL, FilePathName(), FileSync(), _MdfdVec::mdfd_chain, _MdfdVec::mdfd_vfd, mdnblocks(), mdopen(), and NULL.
{
MdfdVec *v;
/*
* NOTE: mdnblocks makes sure we have opened all active segments, so that
* fsync loop will get them all!
*/
mdnblocks(reln, forknum);
v = mdopen(reln, forknum, EXTENSION_FAIL);
while (v != NULL)
{
if (FileSync(v->mdfd_vfd) < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not fsync file \"%s\": %m",
FilePathName(v->mdfd_vfd))));
v = v->mdfd_chain;
}
}
| void mdinit | ( | void | ) |
Definition at line 196 of file md.c.
References ALLOCSET_DEFAULT_INITSIZE, ALLOCSET_DEFAULT_MAXSIZE, ALLOCSET_DEFAULT_MINSIZE, AllocSetContextCreate(), AmCheckpointerProcess, AmStartupProcess, HASHCTL::entrysize, HASHCTL::hash, HASH_CONTEXT, hash_create(), HASH_ELEM, HASH_FUNCTION, HASHCTL::hcxt, IsUnderPostmaster, HASHCTL::keysize, MemSet, and TopMemoryContext.
{
MdCxt = AllocSetContextCreate(TopMemoryContext,
"MdSmgr",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
/*
* Create pending-operations hashtable if we need it. Currently, we need
* it if we are standalone (not under a postmaster) or if we are a startup
* or checkpointer auxiliary process.
*/
if (!IsUnderPostmaster || AmStartupProcess() || AmCheckpointerProcess())
{
HASHCTL hash_ctl;
MemSet(&hash_ctl, 0, sizeof(hash_ctl));
hash_ctl.keysize = sizeof(RelFileNode);
hash_ctl.entrysize = sizeof(PendingOperationEntry);
hash_ctl.hash = tag_hash;
hash_ctl.hcxt = MdCxt;
pendingOpsTable = hash_create("Pending Ops Table",
100L,
&hash_ctl,
HASH_ELEM | HASH_FUNCTION | HASH_CONTEXT);
pendingUnlinks = NIL;
}
}
| BlockNumber mdnblocks | ( | SMgrRelation | reln, | |
| ForkNumber | forknum | |||
| ) |
Definition at line 795 of file md.c.
References _mdfd_openseg(), _mdfd_segpath(), _mdnblocks(), elog, ereport, errcode_for_file_access(), errmsg(), ERROR, EXTENSION_FAIL, FATAL, _MdfdVec::mdfd_chain, mdopen(), and NULL.
Referenced by mdextend(), mdimmedsync(), mdtruncate(), and mdwrite().
{
MdfdVec *v = mdopen(reln, forknum, EXTENSION_FAIL);
BlockNumber nblocks;
BlockNumber segno = 0;
/*
* Skip through any segments that aren't the last one, to avoid redundant
* seeks on them. We have previously verified that these segments are
* exactly RELSEG_SIZE long, and it's useless to recheck that each time.
*
* NOTE: this assumption could only be wrong if another backend has
* truncated the relation. We rely on higher code levels to handle that
* scenario by closing and re-opening the md fd, which is handled via
* relcache flush. (Since the checkpointer doesn't participate in
* relcache flush, it could have segment chain entries for inactive
* segments; that's OK because the checkpointer never needs to compute
* relation size.)
*/
while (v->mdfd_chain != NULL)
{
segno++;
v = v->mdfd_chain;
}
for (;;)
{
nblocks = _mdnblocks(reln, forknum, v);
if (nblocks > ((BlockNumber) RELSEG_SIZE))
elog(FATAL, "segment too big");
if (nblocks < ((BlockNumber) RELSEG_SIZE))
return (segno * ((BlockNumber) RELSEG_SIZE)) + nblocks;
/*
* If segment is exactly RELSEG_SIZE, advance to next one.
*/
segno++;
if (v->mdfd_chain == NULL)
{
/*
* Because we pass O_CREAT, we will create the next segment (with
* zero length) immediately, if the last segment is of length
* RELSEG_SIZE. While perhaps not strictly necessary, this keeps
* the logic simple.
*/
v->mdfd_chain = _mdfd_openseg(reln, forknum, segno, O_CREAT);
if (v->mdfd_chain == NULL)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open file \"%s\": %m",
_mdfd_segpath(reln, forknum, segno))));
}
v = v->mdfd_chain;
}
}
| static MdfdVec * mdopen | ( | SMgrRelation | reln, | |
| ForkNumber | forknum, | |||
| ExtensionBehavior | behavior | |||
| ) | [static] |
Definition at line 553 of file md.c.
References _fdvec_alloc(), _mdnblocks(), Assert, ereport, errcode_for_file_access(), errmsg(), ERROR, EXTENSION_RETURN_NULL, FILE_POSSIBLY_DELETED, IsBootstrapProcessingMode, SMgrRelationData::md_fd, _MdfdVec::mdfd_chain, _MdfdVec::mdfd_segno, _MdfdVec::mdfd_vfd, PathNameOpenFile(), pfree(), PG_BINARY, relpath, and SMgrRelationData::smgr_rnode.
Referenced by _mdfd_getseg(), mdexists(), mdimmedsync(), mdnblocks(), and mdtruncate().
{
MdfdVec *mdfd;
char *path;
File fd;
/* No work if already open */
if (reln->md_fd[forknum])
return reln->md_fd[forknum];
path = relpath(reln->smgr_rnode, forknum);
fd = PathNameOpenFile(path, O_RDWR | PG_BINARY, 0600);
if (fd < 0)
{
/*
* During bootstrap, there are cases where a system relation will be
* accessed (by internal backend processes) before the bootstrap
* script nominally creates it. Therefore, accept mdopen() as a
* substitute for mdcreate() in bootstrap mode only. (See mdcreate)
*/
if (IsBootstrapProcessingMode())
fd = PathNameOpenFile(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY, 0600);
if (fd < 0)
{
if (behavior == EXTENSION_RETURN_NULL &&
FILE_POSSIBLY_DELETED(errno))
{
pfree(path);
return NULL;
}
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open file \"%s\": %m", path)));
}
}
pfree(path);
reln->md_fd[forknum] = mdfd = _fdvec_alloc();
mdfd->mdfd_vfd = fd;
mdfd->mdfd_segno = 0;
mdfd->mdfd_chain = NULL;
Assert(_mdnblocks(reln, forknum, mdfd) <= ((BlockNumber) RELSEG_SIZE));
return mdfd;
}
| void mdpostckpt | ( | void | ) |
Definition at line 1282 of file md.c.
References AbsorbFsyncRequests(), PendingUnlinkEntry::cycle_ctr, ereport, errcode_for_file_access(), errmsg(), linitial, list_delete_first(), MAIN_FORKNUM, mdckpt_cycle_ctr, NIL, pfree(), relpathperm, PendingUnlinkEntry::rnode, unlink(), and WARNING.
{
int absorb_counter;
absorb_counter = UNLINKS_PER_ABSORB;
while (pendingUnlinks != NIL)
{
PendingUnlinkEntry *entry = (PendingUnlinkEntry *) linitial(pendingUnlinks);
char *path;
/*
* New entries are appended to the end, so if the entry is new we've
* reached the end of old entries.
*
* Note: if just the right number of consecutive checkpoints fail, we
* could be fooled here by cycle_ctr wraparound. However, the only
* consequence is that we'd delay unlinking for one more checkpoint,
* which is perfectly tolerable.
*/
if (entry->cycle_ctr == mdckpt_cycle_ctr)
break;
/* Unlink the file */
path = relpathperm(entry->rnode, MAIN_FORKNUM);
if (unlink(path) < 0)
{
/*
* There's a race condition, when the database is dropped at the
* same time that we process the pending unlink requests. If the
* DROP DATABASE deletes the file before we do, we will get ENOENT
* here. rmtree() also has to ignore ENOENT errors, to deal with
* the possibility that we delete the file first.
*/
if (errno != ENOENT)
ereport(WARNING,
(errcode_for_file_access(),
errmsg("could not remove file \"%s\": %m", path)));
}
pfree(path);
/* And remove the list entry */
pendingUnlinks = list_delete_first(pendingUnlinks);
pfree(entry);
/*
* As in mdsync, we don't want to stop absorbing fsync requests for a
* long time when there are many deletions to be done. We can safely
* call AbsorbFsyncRequests() at this point in the loop (note it might
* try to delete list entries).
*/
if (--absorb_counter <= 0)
{
AbsorbFsyncRequests();
absorb_counter = UNLINKS_PER_ABSORB;
}
}
}
| void mdpreckpt | ( | void | ) |
Definition at line 1267 of file md.c.
References mdckpt_cycle_ctr.
{
/*
* Any unlink requests arriving after this point will be assigned the next
* cycle counter, and won't be unlinked until next checkpoint.
*/
mdckpt_cycle_ctr++;
}
| void mdprefetch | ( | SMgrRelation | reln, | |
| ForkNumber | forknum, | |||
| BlockNumber | blocknum | |||
| ) |
Definition at line 634 of file md.c.
References _mdfd_getseg(), Assert, EXTENSION_FAIL, FilePrefetch(), and _MdfdVec::mdfd_vfd.
{
#ifdef USE_PREFETCH
off_t seekpos;
MdfdVec *v;
v = _mdfd_getseg(reln, forknum, blocknum, false, EXTENSION_FAIL);
seekpos = (off_t) BLCKSZ *(blocknum % ((BlockNumber) RELSEG_SIZE));
Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
(void) FilePrefetch(v->mdfd_vfd, seekpos, BLCKSZ);
#endif /* USE_PREFETCH */
}
| void mdread | ( | SMgrRelation | reln, | |
| ForkNumber | forknum, | |||
| BlockNumber | blocknum, | |||
| char * | buffer | |||
| ) |
Definition at line 655 of file md.c.
References _mdfd_getseg(), Assert, RelFileNodeBackend::backend, RelFileNode::dbNode, ereport, errcode(), errcode_for_file_access(), errmsg(), ERROR, EXTENSION_FAIL, FilePathName(), FileRead(), FileSeek(), InRecovery, _MdfdVec::mdfd_vfd, MemSet, RelFileNodeBackend::node, RelFileNode::relNode, SMgrRelationData::smgr_rnode, RelFileNode::spcNode, and zero_damaged_pages.
{
off_t seekpos;
int nbytes;
MdfdVec *v;
TRACE_POSTGRESQL_SMGR_MD_READ_START(forknum, blocknum,
reln->smgr_rnode.node.spcNode,
reln->smgr_rnode.node.dbNode,
reln->smgr_rnode.node.relNode,
reln->smgr_rnode.backend);
v = _mdfd_getseg(reln, forknum, blocknum, false, EXTENSION_FAIL);
seekpos = (off_t) BLCKSZ *(blocknum % ((BlockNumber) RELSEG_SIZE));
Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
if (FileSeek(v->mdfd_vfd, seekpos, SEEK_SET) != seekpos)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not seek to block %u in file \"%s\": %m",
blocknum, FilePathName(v->mdfd_vfd))));
nbytes = FileRead(v->mdfd_vfd, buffer, BLCKSZ);
TRACE_POSTGRESQL_SMGR_MD_READ_DONE(forknum, blocknum,
reln->smgr_rnode.node.spcNode,
reln->smgr_rnode.node.dbNode,
reln->smgr_rnode.node.relNode,
reln->smgr_rnode.backend,
nbytes,
BLCKSZ);
if (nbytes != BLCKSZ)
{
if (nbytes < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not read block %u in file \"%s\": %m",
blocknum, FilePathName(v->mdfd_vfd))));
/*
* Short read: we are at or past EOF, or we read a partial block at
* EOF. Normally this is an error; upper levels should never try to
* read a nonexistent block. However, if zero_damaged_pages is ON or
* we are InRecovery, we should instead return zeroes without
* complaining. This allows, for example, the case of trying to
* update a block that was later truncated away.
*/
if (zero_damaged_pages || InRecovery)
MemSet(buffer, 0, BLCKSZ);
else
ereport(ERROR,
(errcode(ERRCODE_DATA_CORRUPTED),
errmsg("could not read block %u in file \"%s\": read only %d of %d bytes",
blocknum, FilePathName(v->mdfd_vfd),
nbytes, BLCKSZ)));
}
}
| void mdsync | ( | void | ) |
Definition at line 977 of file md.c.
References _mdfd_getseg(), _mdfd_segpath(), AbsorbFsyncRequests(), Assert, bms_first_member(), bms_free(), PendingOperationEntry::canceled, CheckpointStats, CheckpointStatsData::ckpt_agg_sync_time, CheckpointStatsData::ckpt_longest_sync, CheckpointStatsData::ckpt_sync_rels, PendingOperationEntry::cycle_ctr, DEBUG1, elog, enableFsync, ereport, errcode_for_file_access(), errmsg(), ERROR, EXTENSION_RETURN_NULL, FILE_POSSIBLY_DELETED, FilePathName(), FileSync(), HASH_REMOVE, hash_search(), hash_seq_init(), hash_seq_search(), INSTR_TIME_GET_MICROSEC, INSTR_TIME_SET_CURRENT, INSTR_TIME_SUBTRACT, InvalidBackendId, log_checkpoints, longest(), MAX_FORKNUM, _MdfdVec::mdfd_vfd, mdsync_cycle_ctr, NULL, pfree(), PendingOperationEntry::requests, PendingOperationEntry::rnode, and smgropen().
Referenced by SetForwardFsyncRequests().
{
static bool mdsync_in_progress = false;
HASH_SEQ_STATUS hstat;
PendingOperationEntry *entry;
int absorb_counter;
/* Statistics on sync times */
int processed = 0;
instr_time sync_start,
sync_end,
sync_diff;
uint64 elapsed;
uint64 longest = 0;
uint64 total_elapsed = 0;
/*
* This is only called during checkpoints, and checkpoints should only
* occur in processes that have created a pendingOpsTable.
*/
if (!pendingOpsTable)
elog(ERROR, "cannot sync without a pendingOpsTable");
/*
* If we are in the checkpointer, the sync had better include all fsync
* requests that were queued by backends up to this point. The tightest
* race condition that could occur is that a buffer that must be written
* and fsync'd for the checkpoint could have been dumped by a backend just
* before it was visited by BufferSync(). We know the backend will have
* queued an fsync request before clearing the buffer's dirtybit, so we
* are safe as long as we do an Absorb after completing BufferSync().
*/
AbsorbFsyncRequests();
/*
* To avoid excess fsync'ing (in the worst case, maybe a never-terminating
* checkpoint), we want to ignore fsync requests that are entered into the
* hashtable after this point --- they should be processed next time,
* instead. We use mdsync_cycle_ctr to tell old entries apart from new
* ones: new ones will have cycle_ctr equal to the incremented value of
* mdsync_cycle_ctr.
*
* In normal circumstances, all entries present in the table at this point
* will have cycle_ctr exactly equal to the current (about to be old)
* value of mdsync_cycle_ctr. However, if we fail partway through the
* fsync'ing loop, then older values of cycle_ctr might remain when we
* come back here to try again. Repeated checkpoint failures would
* eventually wrap the counter around to the point where an old entry
* might appear new, causing us to skip it, possibly allowing a checkpoint
* to succeed that should not have. To forestall wraparound, any time the
* previous mdsync() failed to complete, run through the table and
* forcibly set cycle_ctr = mdsync_cycle_ctr.
*
* Think not to merge this loop with the main loop, as the problem is
* exactly that that loop may fail before having visited all the entries.
* From a performance point of view it doesn't matter anyway, as this path
* will never be taken in a system that's functioning normally.
*/
if (mdsync_in_progress)
{
/* prior try failed, so update any stale cycle_ctr values */
hash_seq_init(&hstat, pendingOpsTable);
while ((entry = (PendingOperationEntry *) hash_seq_search(&hstat)) != NULL)
{
entry->cycle_ctr = mdsync_cycle_ctr;
}
}
/* Advance counter so that new hashtable entries are distinguishable */
mdsync_cycle_ctr++;
/* Set flag to detect failure if we don't reach the end of the loop */
mdsync_in_progress = true;
/* Now scan the hashtable for fsync requests to process */
absorb_counter = FSYNCS_PER_ABSORB;
hash_seq_init(&hstat, pendingOpsTable);
while ((entry = (PendingOperationEntry *) hash_seq_search(&hstat)) != NULL)
{
ForkNumber forknum;
/*
* If the entry is new then don't process it this time; it might
* contain multiple fsync-request bits, but they are all new. Note
* "continue" bypasses the hash-remove call at the bottom of the loop.
*/
if (entry->cycle_ctr == mdsync_cycle_ctr)
continue;
/* Else assert we haven't missed it */
Assert((CycleCtr) (entry->cycle_ctr + 1) == mdsync_cycle_ctr);
/*
* Scan over the forks and segments represented by the entry.
*
* The bitmap manipulations are slightly tricky, because we can call
* AbsorbFsyncRequests() inside the loop and that could result in
* bms_add_member() modifying and even re-palloc'ing the bitmapsets.
* This is okay because we unlink each bitmapset from the hashtable
* entry before scanning it. That means that any incoming fsync
* requests will be processed now if they reach the table before we
* begin to scan their fork.
*/
for (forknum = 0; forknum <= MAX_FORKNUM; forknum++)
{
Bitmapset *requests = entry->requests[forknum];
int segno;
entry->requests[forknum] = NULL;
entry->canceled[forknum] = false;
while ((segno = bms_first_member(requests)) >= 0)
{
int failures;
/*
* If fsync is off then we don't have to bother opening the
* file at all. (We delay checking until this point so that
* changing fsync on the fly behaves sensibly.)
*/
if (!enableFsync)
continue;
/*
* If in checkpointer, we want to absorb pending requests
* every so often to prevent overflow of the fsync request
* queue. It is unspecified whether newly-added entries will
* be visited by hash_seq_search, but we don't care since we
* don't need to process them anyway.
*/
if (--absorb_counter <= 0)
{
AbsorbFsyncRequests();
absorb_counter = FSYNCS_PER_ABSORB;
}
/*
* The fsync table could contain requests to fsync segments
* that have been deleted (unlinked) by the time we get to
* them. Rather than just hoping an ENOENT (or EACCES on
* Windows) error can be ignored, what we do on error is
* absorb pending requests and then retry. Since mdunlink()
* queues a "cancel" message before actually unlinking, the
* fsync request is guaranteed to be marked canceled after the
* absorb if it really was this case. DROP DATABASE likewise
* has to tell us to forget fsync requests before it starts
* deletions.
*/
for (failures = 0;; failures++) /* loop exits at "break" */
{
SMgrRelation reln;
MdfdVec *seg;
char *path;
int save_errno;
/*
* Find or create an smgr hash entry for this relation.
* This may seem a bit unclean -- md calling smgr? But
* it's really the best solution. It ensures that the
* open file reference isn't permanently leaked if we get
* an error here. (You may say "but an unreferenced
* SMgrRelation is still a leak!" Not really, because the
* only case in which a checkpoint is done by a process
* that isn't about to shut down is in the checkpointer,
* and it will periodically do smgrcloseall(). This fact
* justifies our not closing the reln in the success path
* either, which is a good thing since in non-checkpointer
* cases we couldn't safely do that.)
*/
reln = smgropen(entry->rnode, InvalidBackendId);
/* Attempt to open and fsync the target segment */
seg = _mdfd_getseg(reln, forknum,
(BlockNumber) segno * (BlockNumber) RELSEG_SIZE,
false, EXTENSION_RETURN_NULL);
INSTR_TIME_SET_CURRENT(sync_start);
if (seg != NULL &&
FileSync(seg->mdfd_vfd) >= 0)
{
/* Success; update statistics about sync timing */
INSTR_TIME_SET_CURRENT(sync_end);
sync_diff = sync_end;
INSTR_TIME_SUBTRACT(sync_diff, sync_start);
elapsed = INSTR_TIME_GET_MICROSEC(sync_diff);
if (elapsed > longest)
longest = elapsed;
total_elapsed += elapsed;
processed++;
if (log_checkpoints)
elog(DEBUG1, "checkpoint sync: number=%d file=%s time=%.3f msec",
processed,
FilePathName(seg->mdfd_vfd),
(double) elapsed / 1000);
break; /* out of retry loop */
}
/* Compute file name for use in message */
save_errno = errno;
path = _mdfd_segpath(reln, forknum, (BlockNumber) segno);
errno = save_errno;
/*
* It is possible that the relation has been dropped or
* truncated since the fsync request was entered.
* Therefore, allow ENOENT, but only if we didn't fail
* already on this file. This applies both for
* _mdfd_getseg() and for FileSync, since fd.c might have
* closed the file behind our back.
*
* XXX is there any point in allowing more than one retry?
* Don't see one at the moment, but easy to change the
* test here if so.
*/
if (!FILE_POSSIBLY_DELETED(errno) ||
failures > 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not fsync file \"%s\": %m",
path)));
else
ereport(DEBUG1,
(errcode_for_file_access(),
errmsg("could not fsync file \"%s\" but retrying: %m",
path)));
pfree(path);
/*
* Absorb incoming requests and check to see if a cancel
* arrived for this relation fork.
*/
AbsorbFsyncRequests();
absorb_counter = FSYNCS_PER_ABSORB; /* might as well... */
if (entry->canceled[forknum])
break;
} /* end retry loop */
}
bms_free(requests);
}
/*
* We've finished everything that was requested before we started to
* scan the entry. If no new requests have been inserted meanwhile,
* remove the entry. Otherwise, update its cycle counter, as all the
* requests now in it must have arrived during this cycle.
*/
for (forknum = 0; forknum <= MAX_FORKNUM; forknum++)
{
if (entry->requests[forknum] != NULL)
break;
}
if (forknum <= MAX_FORKNUM)
entry->cycle_ctr = mdsync_cycle_ctr;
else
{
/* Okay to remove it */
if (hash_search(pendingOpsTable, &entry->rnode,
HASH_REMOVE, NULL) == NULL)
elog(ERROR, "pendingOpsTable corrupted");
}
} /* end loop over hashtable entries */
/* Return sync performance metrics for report at checkpoint end */
CheckpointStats.ckpt_sync_rels = processed;
CheckpointStats.ckpt_longest_sync = longest;
CheckpointStats.ckpt_agg_sync_time = total_elapsed;
/* Flag successful completion of mdsync */
mdsync_in_progress = false;
}
| void mdtruncate | ( | SMgrRelation | reln, | |
| ForkNumber | forknum, | |||
| BlockNumber | nblocks | |||
| ) |
Definition at line 857 of file md.c.
References Assert, ereport, errcode_for_file_access(), errmsg(), ERROR, EXTENSION_FAIL, FilePathName(), FileTruncate(), InRecovery, SMgrRelationData::md_fd, _MdfdVec::mdfd_chain, _MdfdVec::mdfd_vfd, mdnblocks(), mdopen(), NULL, pfree(), register_dirty_segment(), relpath, SMgrRelationData::smgr_rnode, and SmgrIsTemp.
{
MdfdVec *v;
BlockNumber curnblk;
BlockNumber priorblocks;
/*
* NOTE: mdnblocks makes sure we have opened all active segments, so that
* truncation loop will get them all!
*/
curnblk = mdnblocks(reln, forknum);
if (nblocks > curnblk)
{
/* Bogus request ... but no complaint if InRecovery */
if (InRecovery)
return;
ereport(ERROR,
(errmsg("could not truncate file \"%s\" to %u blocks: it's only %u blocks now",
relpath(reln->smgr_rnode, forknum),
nblocks, curnblk)));
}
if (nblocks == curnblk)
return; /* no work */
v = mdopen(reln, forknum, EXTENSION_FAIL);
priorblocks = 0;
while (v != NULL)
{
MdfdVec *ov = v;
if (priorblocks > nblocks)
{
/*
* This segment is no longer active (and has already been unlinked
* from the mdfd_chain). We truncate the file, but do not delete
* it, for reasons explained in the header comments.
*/
if (FileTruncate(v->mdfd_vfd, 0) < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not truncate file \"%s\": %m",
FilePathName(v->mdfd_vfd))));
if (!SmgrIsTemp(reln))
register_dirty_segment(reln, forknum, v);
v = v->mdfd_chain;
Assert(ov != reln->md_fd[forknum]); /* we never drop the 1st
* segment */
pfree(ov);
}
else if (priorblocks + ((BlockNumber) RELSEG_SIZE) > nblocks)
{
/*
* This is the last segment we want to keep. Truncate the file to
* the right length, and clear chain link that points to any
* remaining segments (which we shall zap). NOTE: if nblocks is
* exactly a multiple K of RELSEG_SIZE, we will truncate the K+1st
* segment to 0 length but keep it. This adheres to the invariant
* given in the header comments.
*/
BlockNumber lastsegblocks = nblocks - priorblocks;
if (FileTruncate(v->mdfd_vfd, (off_t) lastsegblocks * BLCKSZ) < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not truncate file \"%s\" to %u blocks: %m",
FilePathName(v->mdfd_vfd),
nblocks)));
if (!SmgrIsTemp(reln))
register_dirty_segment(reln, forknum, v);
v = v->mdfd_chain;
ov->mdfd_chain = NULL;
}
else
{
/*
* We still need this segment and 0 or more blocks beyond it, so
* nothing to do here.
*/
v = v->mdfd_chain;
}
priorblocks += RELSEG_SIZE;
}
}
| void mdunlink | ( | RelFileNodeBackend | rnode, | |
| ForkNumber | forkNum, | |||
| bool | isRedo | |||
| ) |
Definition at line 366 of file md.c.
References ForgetRelationFsyncRequests(), InvalidForkNumber, mdunlinkfork(), RelFileNodeBackend::node, and RelFileNodeBackendIsTemp.
{
/*
* We have to clean out any pending fsync requests for the doomed
* relation, else the next mdsync() will fail. There can't be any such
* requests for a temp relation, though. We can send just one request
* even when deleting multiple forks, since the fsync queuing code accepts
* the "InvalidForkNumber = all forks" convention.
*/
if (!RelFileNodeBackendIsTemp(rnode))
ForgetRelationFsyncRequests(rnode.node, forkNum);
/* Now do the per-fork work */
if (forkNum == InvalidForkNumber)
{
for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
mdunlinkfork(rnode, forkNum, isRedo);
}
else
mdunlinkfork(rnode, forkNum, isRedo);
}
| static void mdunlinkfork | ( | RelFileNodeBackend | rnode, | |
| ForkNumber | forkNum, | |||
| bool | isRedo | |||
| ) | [static] |
Definition at line 389 of file md.c.
References CloseTransientFile(), ereport, errcode_for_file_access(), errmsg(), ftruncate, MAIN_FORKNUM, OpenTransientFile(), palloc(), pfree(), PG_BINARY, register_unlink(), RelFileNodeBackendIsTemp, relpath, unlink(), and WARNING.
Referenced by mdunlink().
{
char *path;
int ret;
path = relpath(rnode, forkNum);
/*
* Delete or truncate the first segment.
*/
if (isRedo || forkNum != MAIN_FORKNUM || RelFileNodeBackendIsTemp(rnode))
{
ret = unlink(path);
if (ret < 0 && errno != ENOENT)
ereport(WARNING,
(errcode_for_file_access(),
errmsg("could not remove file \"%s\": %m", path)));
}
else
{
/* truncate(2) would be easier here, but Windows hasn't got it */
int fd;
fd = OpenTransientFile(path, O_RDWR | PG_BINARY, 0);
if (fd >= 0)
{
int save_errno;
ret = ftruncate(fd, 0);
save_errno = errno;
CloseTransientFile(fd);
errno = save_errno;
}
else
ret = -1;
if (ret < 0 && errno != ENOENT)
ereport(WARNING,
(errcode_for_file_access(),
errmsg("could not truncate file \"%s\": %m", path)));
/* Register request to unlink first segment later */
register_unlink(rnode);
}
/*
* Delete any additional segments.
*/
if (ret >= 0)
{
char *segpath = (char *) palloc(strlen(path) + 12);
BlockNumber segno;
/*
* Note that because we loop until getting ENOENT, we will correctly
* remove all inactive segments as well as active ones.
*/
for (segno = 1;; segno++)
{
sprintf(segpath, "%s.%u", path, segno);
if (unlink(segpath) < 0)
{
/* ENOENT is expected after the last segment... */
if (errno != ENOENT)
ereport(WARNING,
(errcode_for_file_access(),
errmsg("could not remove file \"%s\": %m", segpath)));
break;
}
}
pfree(segpath);
}
pfree(path);
}
| void mdwrite | ( | SMgrRelation | reln, | |
| ForkNumber | forknum, | |||
| BlockNumber | blocknum, | |||
| char * | buffer, | |||
| bool | skipFsync | |||
| ) |
Definition at line 725 of file md.c.
References _mdfd_getseg(), Assert, RelFileNodeBackend::backend, RelFileNode::dbNode, ereport, errcode(), errcode_for_file_access(), errhint(), errmsg(), ERROR, EXTENSION_FAIL, FilePathName(), FileSeek(), FileWrite(), _MdfdVec::mdfd_vfd, mdnblocks(), RelFileNodeBackend::node, register_dirty_segment(), RelFileNode::relNode, SMgrRelationData::smgr_rnode, SmgrIsTemp, and RelFileNode::spcNode.
{
off_t seekpos;
int nbytes;
MdfdVec *v;
/* This assert is too expensive to have on normally ... */
#ifdef CHECK_WRITE_VS_EXTEND
Assert(blocknum < mdnblocks(reln, forknum));
#endif
TRACE_POSTGRESQL_SMGR_MD_WRITE_START(forknum, blocknum,
reln->smgr_rnode.node.spcNode,
reln->smgr_rnode.node.dbNode,
reln->smgr_rnode.node.relNode,
reln->smgr_rnode.backend);
v = _mdfd_getseg(reln, forknum, blocknum, skipFsync, EXTENSION_FAIL);
seekpos = (off_t) BLCKSZ *(blocknum % ((BlockNumber) RELSEG_SIZE));
Assert(seekpos < (off_t) BLCKSZ * RELSEG_SIZE);
if (FileSeek(v->mdfd_vfd, seekpos, SEEK_SET) != seekpos)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not seek to block %u in file \"%s\": %m",
blocknum, FilePathName(v->mdfd_vfd))));
nbytes = FileWrite(v->mdfd_vfd, buffer, BLCKSZ);
TRACE_POSTGRESQL_SMGR_MD_WRITE_DONE(forknum, blocknum,
reln->smgr_rnode.node.spcNode,
reln->smgr_rnode.node.dbNode,
reln->smgr_rnode.node.relNode,
reln->smgr_rnode.backend,
nbytes,
BLCKSZ);
if (nbytes != BLCKSZ)
{
if (nbytes < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not write block %u in file \"%s\": %m",
blocknum, FilePathName(v->mdfd_vfd))));
/* short write: complain appropriately */
ereport(ERROR,
(errcode(ERRCODE_DISK_FULL),
errmsg("could not write block %u in file \"%s\": wrote only %d of %d bytes",
blocknum,
FilePathName(v->mdfd_vfd),
nbytes, BLCKSZ),
errhint("Check free disk space.")));
}
if (!skipFsync && !SmgrIsTemp(reln))
register_dirty_segment(reln, forknum, v);
}
| static void register_dirty_segment | ( | SMgrRelation | reln, | |
| ForkNumber | forknum, | |||
| MdfdVec * | seg | |||
| ) | [static] |
Definition at line 1350 of file md.c.
References Assert, DEBUG1, ereport, errcode_for_file_access(), errmsg(), ERROR, FilePathName(), FileSync(), ForwardFsyncRequest(), _MdfdVec::mdfd_segno, _MdfdVec::mdfd_vfd, RelFileNodeBackend::node, RememberFsyncRequest(), SMgrRelationData::smgr_rnode, and SmgrIsTemp.
Referenced by mdextend(), mdtruncate(), and mdwrite().
{
/* Temp relations should never be fsync'd */
Assert(!SmgrIsTemp(reln));
if (pendingOpsTable)
{
/* push it into local pending-ops table */
RememberFsyncRequest(reln->smgr_rnode.node, forknum, seg->mdfd_segno);
}
else
{
if (ForwardFsyncRequest(reln->smgr_rnode.node, forknum, seg->mdfd_segno))
return; /* passed it off successfully */
ereport(DEBUG1,
(errmsg("could not forward fsync request because request queue is full")));
if (FileSync(seg->mdfd_vfd) < 0)
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not fsync file \"%s\": %m",
FilePathName(seg->mdfd_vfd))));
}
}
| static void register_unlink | ( | RelFileNodeBackend | rnode | ) | [static] |
Definition at line 1386 of file md.c.
References Assert, ForwardFsyncRequest(), IsUnderPostmaster, MAIN_FORKNUM, RelFileNodeBackend::node, pg_usleep(), RelFileNodeBackendIsTemp, RememberFsyncRequest(), and UNLINK_RELATION_REQUEST.
Referenced by mdunlinkfork().
{
/* Should never be used with temp relations */
Assert(!RelFileNodeBackendIsTemp(rnode));
if (pendingOpsTable)
{
/* push it into local pending-ops table */
RememberFsyncRequest(rnode.node, MAIN_FORKNUM,
UNLINK_RELATION_REQUEST);
}
else
{
/*
* Notify the checkpointer about it. If we fail to queue the request
* message, we have to sleep and try again, because we can't simply
* delete the file now. Ugly, but hopefully won't happen often.
*
* XXX should we just leave the file orphaned instead?
*/
Assert(IsUnderPostmaster);
while (!ForwardFsyncRequest(rnode.node, MAIN_FORKNUM,
UNLINK_RELATION_REQUEST))
pg_usleep(10000L); /* 10 msec seems a good number */
}
}
| void RememberFsyncRequest | ( | RelFileNode | rnode, | |
| ForkNumber | forknum, | |||
| BlockNumber | segno | |||
| ) |
Definition at line 1435 of file md.c.
References Assert, bms_add_member(), bms_free(), PendingOperationEntry::canceled, PendingOperationEntry::cycle_ctr, PendingUnlinkEntry::cycle_ctr, RelFileNode::dbNode, FORGET_DATABASE_FSYNC, FORGET_RELATION_FSYNC, HASH_ENTER, HASH_FIND, hash_search(), hash_seq_init(), hash_seq_search(), InvalidForkNumber, lappend(), lfirst, list_delete_cell(), list_head(), lnext, MAIN_FORKNUM, mdckpt_cycle_ctr, mdsync_cycle_ctr, MemoryContextSwitchTo(), MemSet, NULL, palloc(), pfree(), PendingOperationEntry::requests, PendingUnlinkEntry::rnode, PendingOperationEntry::rnode, and UNLINK_RELATION_REQUEST.
Referenced by AbsorbFsyncRequests(), ForgetDatabaseFsyncRequests(), ForgetRelationFsyncRequests(), register_dirty_segment(), and register_unlink().
{
Assert(pendingOpsTable);
if (segno == FORGET_RELATION_FSYNC)
{
/* Remove any pending requests for the relation (one or all forks) */
PendingOperationEntry *entry;
entry = (PendingOperationEntry *) hash_search(pendingOpsTable,
&rnode,
HASH_FIND,
NULL);
if (entry)
{
/*
* We can't just delete the entry since mdsync could have an
* active hashtable scan. Instead we delete the bitmapsets; this
* is safe because of the way mdsync is coded. We also set the
* "canceled" flags so that mdsync can tell that a cancel arrived
* for the fork(s).
*/
if (forknum == InvalidForkNumber)
{
/* remove requests for all forks */
for (forknum = 0; forknum <= MAX_FORKNUM; forknum++)
{
bms_free(entry->requests[forknum]);
entry->requests[forknum] = NULL;
entry->canceled[forknum] = true;
}
}
else
{
/* remove requests for single fork */
bms_free(entry->requests[forknum]);
entry->requests[forknum] = NULL;
entry->canceled[forknum] = true;
}
}
}
else if (segno == FORGET_DATABASE_FSYNC)
{
/* Remove any pending requests for the entire database */
HASH_SEQ_STATUS hstat;
PendingOperationEntry *entry;
ListCell *cell,
*prev,
*next;
/* Remove fsync requests */
hash_seq_init(&hstat, pendingOpsTable);
while ((entry = (PendingOperationEntry *) hash_seq_search(&hstat)) != NULL)
{
if (entry->rnode.dbNode == rnode.dbNode)
{
/* remove requests for all forks */
for (forknum = 0; forknum <= MAX_FORKNUM; forknum++)
{
bms_free(entry->requests[forknum]);
entry->requests[forknum] = NULL;
entry->canceled[forknum] = true;
}
}
}
/* Remove unlink requests */
prev = NULL;
for (cell = list_head(pendingUnlinks); cell; cell = next)
{
PendingUnlinkEntry *entry = (PendingUnlinkEntry *) lfirst(cell);
next = lnext(cell);
if (entry->rnode.dbNode == rnode.dbNode)
{
pendingUnlinks = list_delete_cell(pendingUnlinks, cell, prev);
pfree(entry);
}
else
prev = cell;
}
}
else if (segno == UNLINK_RELATION_REQUEST)
{
/* Unlink request: put it in the linked list */
MemoryContext oldcxt = MemoryContextSwitchTo(MdCxt);
PendingUnlinkEntry *entry;
/* PendingUnlinkEntry doesn't store forknum, since it's always MAIN */
Assert(forknum == MAIN_FORKNUM);
entry = palloc(sizeof(PendingUnlinkEntry));
entry->rnode = rnode;
entry->cycle_ctr = mdckpt_cycle_ctr;
pendingUnlinks = lappend(pendingUnlinks, entry);
MemoryContextSwitchTo(oldcxt);
}
else
{
/* Normal case: enter a request to fsync this segment */
MemoryContext oldcxt = MemoryContextSwitchTo(MdCxt);
PendingOperationEntry *entry;
bool found;
entry = (PendingOperationEntry *) hash_search(pendingOpsTable,
&rnode,
HASH_ENTER,
&found);
/* if new entry, initialize it */
if (!found)
{
entry->cycle_ctr = mdsync_cycle_ctr;
MemSet(entry->requests, 0, sizeof(entry->requests));
MemSet(entry->canceled, 0, sizeof(entry->canceled));
}
/*
* NB: it's intentional that we don't change cycle_ctr if the entry
* already exists. The cycle_ctr must represent the oldest fsync
* request that could be in the entry.
*/
entry->requests[forknum] = bms_add_member(entry->requests[forknum],
(int) segno);
MemoryContextSwitchTo(oldcxt);
}
}
| void SetForwardFsyncRequests | ( | void | ) |
Definition at line 233 of file md.c.
References Assert, hash_destroy(), mdsync(), and NIL.
Referenced by StartupXLOG().
{
/* Perform any pending fsyncs we may have queued up, then drop table */
if (pendingOpsTable)
{
mdsync();
hash_destroy(pendingOpsTable);
}
pendingOpsTable = NULL;
/*
* We should not have any pending unlink requests, since mdunlink doesn't
* queue unlink requests when isRedo.
*/
Assert(pendingUnlinks == NIL);
}
CycleCtr mdckpt_cycle_ctr = 0 [static] |
Definition at line 163 of file md.c.
Referenced by mdpostckpt(), mdpreckpt(), and RememberFsyncRequest().
MemoryContext MdCxt [static] |
CycleCtr mdsync_cycle_ctr = 0 [static] |
Definition at line 162 of file md.c.
Referenced by mdsync(), and RememberFsyncRequest().
HTAB* pendingOpsTable = NULL [static] |
List* pendingUnlinks = NIL [static] |
1.7.1