diff options
Diffstat (limited to 'src/backend/storage/smgr/md.c')
| -rw-r--r-- | src/backend/storage/smgr/md.c | 152 |
1 files changed, 106 insertions, 46 deletions
diff --git a/src/backend/storage/smgr/md.c b/src/backend/storage/smgr/md.c index e3cc00ca1a9..e8396b698d4 100644 --- a/src/backend/storage/smgr/md.c +++ b/src/backend/storage/smgr/md.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/storage/smgr/md.c,v 1.126 2007/01/17 00:17:21 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/storage/smgr/md.c,v 1.127 2007/01/17 16:25:01 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -31,6 +31,10 @@ /* interval for calling AbsorbFsyncRequests in mdsync */ #define FSYNCS_PER_ABSORB 10 +/* special values for the segno arg to RememberFsyncRequest */ +#define FORGET_RELATION_FSYNC (InvalidBlockNumber) +#define FORGET_DATABASE_FSYNC (InvalidBlockNumber-1) + /* * On Windows, we have to interpret EACCES as possibly meaning the same as * ENOENT, because if a file is unlinked-but-not-yet-gone on that platform, @@ -258,30 +262,7 @@ mdunlink(RelFileNode rnode, bool isRedo) * We have to clean out any pending fsync requests for the doomed relation, * else the next mdsync() will fail. */ - if (pendingOpsTable) - { - /* standalone backend or startup process: fsync state is local */ - RememberFsyncRequest(rnode, InvalidBlockNumber); - } - else if (IsUnderPostmaster) - { - /* - * Notify the bgwriter about it. If we fail to queue the revoke - * 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 - * bgwriter will always empty the queue soon. - */ - while (!ForwardFsyncRequest(rnode, InvalidBlockNumber)) - pg_usleep(10000L); /* 10 msec seems a good number */ - /* - * Note we don't wait for the bgwriter to actually absorb the - * revoke message; see mdsync() for the implications. - */ - } + ForgetRelationFsyncRequests(rnode); path = relpath(rnode); @@ -894,7 +875,8 @@ mdsync(void) * what we will do is retry the whole process after absorbing fsync * request messages again. Since mdunlink() queues a "revoke" message * before actually unlinking, the fsync request is guaranteed to be gone - * the second time if it really was this case. + * the second time if it really was this case. DROP DATABASE likewise + * has to tell us to forget fsync requests before it starts deletions. */ do { HASH_SEQ_STATUS hstat; @@ -1043,17 +1025,58 @@ register_dirty_segment(SMgrRelation reln, MdfdVec *seg) * We stuff the fsync request into the local hash table for execution * during the bgwriter's next checkpoint. * - * segno == InvalidBlockNumber is a "revoke" request: remove any pending - * fsync requests for the whole relation. + * The range of possible segment numbers is way less than the range of + * BlockNumber, so we can reserve high values of segno for special purposes. + * We define two: FORGET_RELATION_FSYNC means to drop pending fsyncs for + * a relation, and FORGET_DATABASE_FSYNC means to drop pending fsyncs for + * a whole database. (These are a tad slow because the hash table has to be + * searched linearly, but it doesn't seem worth rethinking the table structure + * for them.) */ void RememberFsyncRequest(RelFileNode rnode, BlockNumber segno) { Assert(pendingOpsTable); - if (segno != InvalidBlockNumber) + if (segno == FORGET_RELATION_FSYNC) + { + /* Remove any pending requests for the entire relation */ + HASH_SEQ_STATUS hstat; + PendingOperationEntry *entry; + + hash_seq_init(&hstat, pendingOpsTable); + while ((entry = (PendingOperationEntry *) hash_seq_search(&hstat)) != NULL) + { + if (RelFileNodeEquals(entry->tag.rnode, rnode)) + { + /* Okay, delete this entry */ + if (hash_search(pendingOpsTable, &entry->tag, + HASH_REMOVE, NULL) == NULL) + elog(ERROR, "pendingOpsTable corrupted"); + } + } + } + else if (segno == FORGET_DATABASE_FSYNC) + { + /* Remove any pending requests for the entire database */ + HASH_SEQ_STATUS hstat; + PendingOperationEntry *entry; + + hash_seq_init(&hstat, pendingOpsTable); + while ((entry = (PendingOperationEntry *) hash_seq_search(&hstat)) != NULL) + { + if (entry->tag.rnode.dbNode == rnode.dbNode) + { + /* Okay, delete this entry */ + if (hash_search(pendingOpsTable, &entry->tag, + HASH_REMOVE, NULL) == NULL) + elog(ERROR, "pendingOpsTable corrupted"); + } + } + } + else { - /* Enter a request to fsync this segment */ + /* Normal case: enter a request to fsync this segment */ PendingOperationTag key; PendingOperationEntry *entry; bool found; @@ -1070,29 +1093,66 @@ RememberFsyncRequest(RelFileNode rnode, BlockNumber segno) if (!found) /* new entry, so initialize it */ entry->failures = 0; } - else +} + +/* + * ForgetRelationFsyncRequests -- ensure any fsyncs for a rel are forgotten + */ +void +ForgetRelationFsyncRequests(RelFileNode rnode) +{ + if (pendingOpsTable) + { + /* standalone backend or startup process: fsync state is local */ + RememberFsyncRequest(rnode, FORGET_RELATION_FSYNC); + } + else if (IsUnderPostmaster) { /* - * Remove any pending requests for the entire relation. (This is a - * tad slow but it doesn't seem worth rethinking the table structure.) + * Notify the bgwriter about it. If we fail to queue the revoke + * 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 + * bgwriter will always empty the queue soon. */ - HASH_SEQ_STATUS hstat; - PendingOperationEntry *entry; + while (!ForwardFsyncRequest(rnode, FORGET_RELATION_FSYNC)) + pg_usleep(10000L); /* 10 msec seems a good number */ + /* + * Note we don't wait for the bgwriter to actually absorb the + * revoke message; see mdsync() for the implications. + */ + } +} - hash_seq_init(&hstat, pendingOpsTable); - while ((entry = (PendingOperationEntry *) hash_seq_search(&hstat)) != NULL) - { - if (RelFileNodeEquals(entry->tag.rnode, rnode)) - { - /* Okay, delete this entry */ - if (hash_search(pendingOpsTable, &entry->tag, - HASH_REMOVE, NULL) == NULL) - elog(ERROR, "pendingOpsTable corrupted"); - } - } +/* + * ForgetDatabaseFsyncRequests -- ensure any fsyncs for a DB are forgotten + */ +void +ForgetDatabaseFsyncRequests(Oid dbid) +{ + RelFileNode rnode; + + rnode.dbNode = dbid; + rnode.spcNode = 0; + rnode.relNode = 0; + + if (pendingOpsTable) + { + /* standalone backend or startup process: fsync state is local */ + RememberFsyncRequest(rnode, FORGET_DATABASE_FSYNC); + } + else if (IsUnderPostmaster) + { + /* see notes in ForgetRelationFsyncRequests */ + while (!ForwardFsyncRequest(rnode, FORGET_DATABASE_FSYNC)) + pg_usleep(10000L); /* 10 msec seems a good number */ } } + /* * _fdvec_alloc() -- Make a MdfdVec object. */ |