/*
* mdopen() -- Open the specified relation. ereport's on failure.
* (Optionally, can return NULL instead of ereport for ENOENT.)
*
* Note we only open the first segment, when there are multiple segments.
*/
static MdfdVec *
mdopen(SMgrRelation reln, bool allowNotFound)
{
MdfdVec *mdfd;
char *path;
File fd;
/* No work if already open */
if (reln->md_fd)
return reln->md_fd;
path = relpath(reln->smgr_rnode);
fd = FileNameOpenFile(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 = FileNameOpenFile(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY, 0600);
if (fd < 0)
{
pfree(path);
if (allowNotFound && errno == ENOENT)
return NULL;
ereport(ERROR,
(errcode_for_file_access(),
errmsg("could not open relation %u/%u/%u: %m",
reln->smgr_rnode.spcNode,
reln->smgr_rnode.dbNode,
reln->smgr_rnode.relNode)));
}
}
pfree(path);
reln->md_fd = mdfd = _fdvec_alloc();
mdfd->mdfd_vfd = fd;
mdfd->mdfd_segno = 0;
#ifndef LET_OS_MANAGE_FILESIZE
mdfd->mdfd_chain = NULL;
Assert(_mdnblocks(fd, BLCKSZ) <= ((BlockNumber) RELSEG_SIZE));
#endif
return mdfd;
}
/*
* mdopen() -- Open the specified relation.
*
* Note we only open the first segment, when there are multiple segments.
*
* If first segment is not present, either ereport or return NULL according
* to "behavior". We treat EXTENSION_CREATE the same as EXTENSION_FAIL;
* EXTENSION_CREATE means it's OK to extend an existing relation, not to
* invent one out of whole cloth.
*/
static MdfdVec *
mdopen(SMgrRelation reln, ForkNumber forknum, ExtensionBehavior behavior)
{
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;
}
/*
* mdcreate() -- Create a new relation on magnetic disk.
*
* If isRedo is true, it's okay for the relation to exist already.
*/
bool
mdcreate(SMgrRelation reln, bool isRedo)
{
char *path;
File fd;
if (isRedo && reln->md_fd != NULL)
return true; /* created and opened already... */
Assert(reln->md_fd == NULL);
path = relpath(reln->smgr_rnode);
fd = FileNameOpenFile(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 = FileNameOpenFile(path, O_RDWR | PG_BINARY, 0600);
if (fd < 0)
{
pfree(path);
/* be sure to return the error reported by create, not open */
errno = save_errno;
return false;
}
errno = 0;
}
pfree(path);
reln->md_fd = _fdvec_alloc();
reln->md_fd->mdfd_vfd = fd;
reln->md_fd->mdfd_segno = 0;
#ifndef LET_OS_MANAGE_FILESIZE
reln->md_fd->mdfd_chain = NULL;
#endif
return true;
}
/*
* mdcreate() -- Create a new relation on magnetic disk.
*
* If isRedo is true, it's okay for the relation to exist already.
*/
void
mdcreate(SMgrRelation reln, ForkNumber forkNum, bool isRedo)
{
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;
}
/*
* Open the specified segment of the relation,
* and make a MdfdVec object for it. Returns NULL on failure.
*/
static MdfdVec *
_mdfd_openseg(SMgrRelation reln, BlockNumber segno, int oflags)
{
MdfdVec *v;
int fd;
char *path,
*fullpath;
path = relpath(reln->smgr_rnode);
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;
/* 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(fd, BLCKSZ) <= ((BlockNumber) RELSEG_SIZE));
/* all done */
return v;
}