More RAWPART support

Use mmap to read and initialize the meta pages, raw device
may not support read/write syscalls.
This commit is contained in:
Howard Chu 2018-06-11 10:12:03 +01:00 committed by Howard Chu
parent 747f5d3594
commit 4e7586c9e4
No known key found for this signature in database
GPG key ID: FD2A70B44AB11BA7

View file

@ -4040,6 +4040,8 @@ fail:
return rc;
}
static int ESECT mdb_env_map(MDB_env *env, void *addr);
/** Read the environment parameters of a DB environment before
* mapping it into memory.
* @param[in] env the environment handle
@ -4056,6 +4058,31 @@ mdb_env_read_header(MDB_env *env, int prev, MDB_meta *meta)
int i, rc, off;
enum { Size = sizeof(pbuf) };
if (env->me_flags & MDB_RAWPART) {
#define VM_ALIGN 0x200000
env->me_mapsize += VM_ALIGN-1;
env->me_mapsize &= ~(VM_ALIGN-1);
env->me_psize = env->me_os_psize;
rc = mdb_env_map(env, NULL);
if (rc) {
DPRINTF(("mdb_env_map: %s", mdb_strerror(rc)));
return rc;
}
p = (MDB_page *)env->me_map;
for (i=0; i<NUM_METAS; i++) {
if (!F_ISSET(p->mp_flags, P_META))
return ENOENT;
if (env->me_metas[i]->mm_magic != MDB_MAGIC)
return MDB_INVALID;
if (env->me_metas[i]->mm_version != MDB_DATA_VERSION)
return MDB_VERSION_MISMATCH;
if (i == 0 || env->me_metas[i]->mm_txnid > meta->mm_txnid)
*meta = *env->me_metas[i];
p = (MDB_page *)((char *)p + env->me_psize);
}
return 0;
}
/* We don't know the page size yet, so use a minimum value.
* Read both meta pages so we can use the latest one.
*/
@ -4152,6 +4179,18 @@ mdb_env_init_meta(MDB_env *env, MDB_meta *meta)
psize = env->me_psize;
if ((env->me_flags & (MDB_RAWPART|MDB_WRITEMAP)) == (MDB_RAWPART|MDB_WRITEMAP)) {
p = (MDB_page *)env->me_map;
p->mp_pgno = 0;
p->mp_flags = P_META;
*(MDB_meta *)METADATA(p) = *meta;
q = (MDB_page *)((char *)p + psize);
q->mp_pgno = 1;
q->mp_flags = P_META;
*(MDB_meta *)METADATA(q) = *meta;
return 0;
}
p = calloc(NUM_METAS, psize);
if (!p)
return ENOMEM;
@ -5460,8 +5499,11 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode
if (rc)
return ErrCode();
flags &= ~MDB_RAWPART;
if (S_ISBLK(st.st_mode))
if (S_ISBLK(st.st_mode)) {
flags |= MDB_RAWPART | MDB_NOSUBDIR;
if (!env->me_mapsize)
env->me_mapsize = DEFAULT_MAPSIZE;
}
}
#endif
flags |= MDB_ENV_ACTIVE; /* tell mdb_env_close0() to clean up */