ISAR/libmdbx
3
0
Fork 0
mirror of https://github.com/isar/libmdbx.git synced 2025-01-10 12:24:12 +08:00
Code Issues Packages Projects Releases Wiki Activity

mdbx: backport - don't madvise(MADV_REMOVE).

Browse Source 
Avoid lost changes and corruption in case a collision
between mdbx_env_open() in one process and write-txn with
next-pgno updates in an another process.

Change-Id: I890db9251edbd77ac0ace10bed10a24517d709ec
This commit is contained in:
Leo Yuriev 2017-07-26 13:14:19 +03:00
parent 4874852b79
commit f55c30f286
1 changed files with 3 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
mdb.c
View File

@ -4341,7 +4341,7 @@ mdb_env_create(MDB_env **env)
} }
static int __cold static int __cold
mdb_env_map(MDB_env *env, void *addr, size_t usedsize) mdb_env_map(MDB_env *env, void *addr)
{ {
unsigned flags = env->me_flags; unsigned flags = env->me_flags;
@ -4381,12 +4381,6 @@ mdb_env_map(MDB_env *env, void *addr, size_t usedsize)
} }
#endif #endif
#ifdef MADV_REMOVE
if (flags & MDB_WRITEMAP) {
(void) madvise(env->me_map + usedsize, env->me_mapsize - usedsize, MADV_REMOVE);
}
#endif
/* Turn on/off readahead. It's harmful when the DB is larger than RAM. */ /* Turn on/off readahead. It's harmful when the DB is larger than RAM. */
if (madvise(env->me_map, env->me_mapsize, (flags & MDB_NORDAHEAD) ? MADV_RANDOM : MADV_WILLNEED)) if (madvise(env->me_map, env->me_mapsize, (flags & MDB_NORDAHEAD) ? MADV_RANDOM : MADV_WILLNEED))
return errno; return errno;
@ -4439,7 +4433,7 @@ mdb_env_set_mapsize(MDB_env *env, size_t size)
#endif #endif
env->me_mapsize = size; env->me_mapsize = size;
old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL; old = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : NULL;
rc = mdb_env_map(env, old, usedsize); rc = mdb_env_map(env, old);
if (rc) if (rc)
return rc; return rc;
} }
@ -4557,8 +4551,7 @@ mdb_env_open2(MDB_env *env, MDB_meta *meta)
newenv = 0; newenv = 0;
} }
const size_t usedsize = (meta->mm_last_pg + 1) * env->me_psize; rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta->mm_address : NULL);
rc = mdb_env_map(env, (flags & MDB_FIXEDMAP) ? meta->mm_address : NULL, usedsize);
if (rc) if (rc)
return rc; return rc;