diff options
Diffstat (limited to 'db2/mp/mp_bh.c')
| -rw-r--r-- | db2/mp/mp_bh.c | 92 |
1 files changed, 59 insertions, 33 deletions
diff --git a/db2/mp/mp_bh.c b/db2/mp/mp_bh.c index a707603eec..578abedcb6 100644 --- a/db2/mp/mp_bh.c +++ b/db2/mp/mp_bh.c @@ -7,7 +7,7 @@ #include "config.h" #ifndef lint -static const char sccsid[] = "@(#)mp_bh.c 10.21 (Sleepycat) 10/25/97"; +static const char sccsid[] = "@(#)mp_bh.c 10.23 (Sleepycat) 11/26/97"; #endif /* not lint */ #ifndef NO_SYSTEM_INCLUDES @@ -40,7 +40,6 @@ __memp_bhwrite(dbmp, mfp, bhp, restartp, wrotep) BH *bhp; int *restartp, *wrotep; { - DBT dbt; DB_MPOOLFILE *dbmfp; DB_MPREG *mpreg; @@ -53,7 +52,7 @@ __memp_bhwrite(dbmp, mfp, bhp, restartp, wrotep) * Walk the process' DB_MPOOLFILE list and find a file descriptor for * the file. We also check that the descriptor is open for writing. * If we find a descriptor on the file that's not open for writing, we - * try and upgrade it to make it writeable. + * try and upgrade it to make it writeable. If that fails, we're done. */ LOCKHANDLE(dbmp, dbmp->mutexp); for (dbmfp = TAILQ_FIRST(&dbmp->dbmfq); @@ -86,18 +85,34 @@ __memp_bhwrite(dbmp, mfp, bhp, restartp, wrotep) } /* - * Try and open the file; ignore any error, assume it's a permissions - * problem. + * Try and open the file, attaching to the underlying shared area. * * XXX - * There's no negative cache here, so we may repeatedly try and open - * files that we have previously tried (and failed) to open. + * Don't try to attach to temporary files. There are two problems in + * trying to do that. First, if we have different privileges than the + * process that "owns" the temporary file, we might create the backing + * disk file such that the owning process couldn't read/write its own + * buffers, e.g., memp_trickle() running as root creating a file owned + * as root, mode 600. Second, if the temporary file has already been + * created, we don't have any way of finding out what its real name is, + * and, even if we did, it was already unlinked (so that it won't be + * left if the process dies horribly). This decision causes a problem, + * however: if the temporary file consumes the entire buffer cache, + * and the owner doesn't flush the buffers to disk, we could end up + * with resource starvation, and the memp_trickle() thread couldn't do + * anything about it. That's a pretty unlikely scenario, though. + * + * XXX + * There's no negative cache, so we may repeatedly try and open files + * that we have previously tried (and failed) to open. + * + * Ignore any error, assume it's a permissions problem. */ - dbt.size = mfp->pgcookie_len; - dbt.data = R_ADDR(dbmp, mfp->pgcookie_off); - if (__memp_fopen(dbmp, R_ADDR(dbmp, mfp->path_off), - mfp->ftype, 0, 0, mfp->stat.st_pagesize, - mfp->lsn_off, &dbt, R_ADDR(dbmp, mfp->fileid_off), 0, &dbmfp) != 0) + if (F_ISSET(mfp, MP_TEMP)) + return (0); + + if (__memp_fopen(dbmp, mfp, R_ADDR(dbmp, mfp->path_off), mfp->ftype, + 0, 0, mfp->stat.st_pagesize, 0, NULL, NULL, 0, &dbmfp) != 0) return (0); found: return (__memp_pgwrite(dbmfp, bhp, restartp, wrotep)); @@ -144,7 +159,7 @@ __memp_pgread(dbmfp, bhp, can_create) UNLOCKHANDLE(dbmp, dbmfp->mutexp); __db_err(dbmp->dbenv, "%s: page %lu doesn't exist, create flag not set", - dbmfp->path, (u_long)bhp->pgno); + __memp_fn(dbmfp), (u_long)bhp->pgno); goto err; } UNLOCKHANDLE(dbmp, dbmfp->mutexp); @@ -270,12 +285,14 @@ __memp_pgwrite(dbmfp, bhp, restartp, wrotep) /* Temporary files may not yet have been created. */ LOCKHANDLE(dbmp, dbmfp->mutexp); - if (dbmfp->fd == -1 && ((ret = __db_appname(dbenv, DB_APP_TMP, - NULL, NULL, &dbmfp->fd, NULL)) != 0 || dbmfp->fd == -1)) { - UNLOCKHANDLE(dbmp, dbmfp->mutexp); - __db_err(dbenv, "unable to create temporary backing file"); - goto err; - } + if (dbmfp->fd == -1) + if ((ret = __db_appname(dbenv, DB_APP_TMP, + NULL, NULL, &dbmfp->fd, NULL)) != 0 || dbmfp->fd == -1) { + UNLOCKHANDLE(dbmp, dbmfp->mutexp); + __db_err(dbenv, + "unable to create temporary backing file"); + goto err; + } /* Write the page out. */ if ((ret = __db_seek(dbmfp->fd, pagesize, bhp->pgno, 0, SEEK_SET)) != 0) @@ -350,8 +367,8 @@ __memp_pgwrite(dbmfp, bhp, restartp, wrotep) return (0); -syserr: __db_err(dbenv, - "%s: %s failed for page %lu", dbmfp->path, fail, (u_long)bhp->pgno); +syserr: __db_err(dbenv, "%s: %s failed for page %lu", + __memp_fn(dbmfp), fail, (u_long)bhp->pgno); err: UNLOCKBUFFER(dbmp, bhp); LOCKREGION(dbmp); @@ -416,7 +433,7 @@ __memp_pg(dbmfp, bhp, is_pgin) err: UNLOCKHANDLE(dbmp, dbmp->mutexp); __db_err(dbmp->dbenv, "%s: %s failed for page %lu", - dbmfp->path, is_pgin ? "pgin" : "pgout", (u_long)bhp->pgno); + __memp_fn(dbmfp), is_pgin ? "pgin" : "pgout", (u_long)bhp->pgno); return (ret); } @@ -462,7 +479,8 @@ __memp_upgrade(dbmp, dbmfp, mfp) DB_MPOOLFILE *dbmfp; MPOOLFILE *mfp; { - int fd; + int fd, ret; + char *rpath; /* * !!! @@ -477,16 +495,24 @@ __memp_upgrade(dbmp, dbmfp, mfp) if (F_ISSET(dbmfp, MP_UPGRADE_FAIL)) return (1); - /* Try the open. */ - if (__db_open(R_ADDR(dbmp, mfp->path_off), 0, 0, 0, &fd) != 0) { + /* + * Calculate the real name for this file and try to open it read/write. + * We know we have a valid pathname for the file because it's the only + * way we could have gotten a file descriptor of any kind. + */ + if ((ret = __db_appname(dbmp->dbenv, DB_APP_DATA, + NULL, R_ADDR(dbmp, mfp->path_off), NULL, &rpath)) != 0) + return (ret); + if (__db_open(rpath, 0, 0, 0, &fd) != 0) { F_SET(dbmfp, MP_UPGRADE_FAIL); - return (1); + ret = 1; + } else { + /* Swap the descriptors and set the upgrade flag. */ + (void)__db_close(dbmfp->fd); + dbmfp->fd = fd; + F_SET(dbmfp, MP_UPGRADE); + ret = 0; } - - /* Swap the descriptors and set the upgrade flag. */ - (void)__db_close(dbmfp->fd); - dbmfp->fd = fd; - F_SET(dbmfp, MP_UPGRADE); - - return (0); + FREES(rpath); + return (ret); } |