ISAR/libmdbx
3
0
Fork 0
mirror of https://github.com/isar/libmdbx.git synced 2025-01-04 18:14:12 +08:00
Code Issues Packages Projects Releases Wiki Activity

mdbx: rework/refine mdbx_mresize() for POSIX and MAP_FIXED_NOREPLACE (Linux 4.17).

Browse Source 
Change-Id: I2e531b5e3e009b2a18ae1901fc7e2e6e4df667cd
This commit is contained in:
Leonid Yuriev 2020-09-22 03:56:59 +03:00
parent 5c89717ecd
commit 24c0749eb8
1 changed files with 90 additions and 46 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

136
src/osal.c
View File

@ -1589,45 +1589,87 @@ retry_mapview:;
map->current = size; map->current = size;
} }
if (limit != map->limit) { if (limit == map->limit)
return MDBX_SUCCESS;
if (limit < map->limit) {
/* unmap an excess at end of mapping. */
if (unlikely(munmap(map->dxb + limit, map->limit - limit)))
return errno;
map->limit = limit;
return MDBX_SUCCESS;
}
assert(limit > map->limit);
uint8_t *ptr = MAP_FAILED;
#if defined(MREMAP_MAYMOVE) #if defined(MREMAP_MAYMOVE)
void *ptr = ptr = mremap(map->address, map->limit, limit, may_move ? MREMAP_MAYMOVE : 0);
mremap(map->address, map->limit, limit, may_move ? MREMAP_MAYMOVE : 0); if (ptr == MAP_FAILED) {
if (ptr == MAP_FAILED) { const int err = errno;
rc = errno; switch (err) {
switch (rc) { default:
return err;
case EAGAIN:
case ENOMEM:
return MDBX_UNABLE_EXTEND_MAPSIZE;
case EFAULT /* MADV_DODUMP / MADV_DONTDUMP are mixed for mmap-range */:
break;
}
}
#endif /* MREMAP_MAYMOVE */
const unsigned mmap_flags =
MAP_CONCEAL | MAP_SHARED | MAP_FILE |
(F_ISSET(flags, MDBX_UTTERLY_NOSYNC) ? MAP_NOSYNC : 0);
const unsigned mmap_prot =
(flags & MDBX_WRITEMAP) ? PROT_READ | PROT_WRITE : PROT_READ;
if (ptr == MAP_FAILED) {
/* Try to mmap additional space beyond the end of mapping. */
ptr = mmap(map->dxb + map->limit, limit - map->limit, mmap_prot,
mmap_flags
#if defined(MAP_FIXED_NOREPLACE)
| MAP_FIXED_NOREPLACE
#endif /* MAP_FIXED_NOREPLACE */
,
map->fd, map->limit);
if (ptr == map->dxb + map->limit)
ptr = map->dxb;
else if (ptr != MAP_FAILED) {
/* the desired address is busy, unmap unsuitable one */
if (unlikely(munmap(ptr, limit - map->limit)))
return errno;
ptr = MAP_FAILED;
} else {
const int err = errno;
switch (err) {
default:
return err;
case EAGAIN: case EAGAIN:
case ENOMEM: case ENOMEM:
case EFAULT /* MADV_DODUMP / MADV_DONTDUMP are mixed for mmap-range */: return MDBX_UNABLE_EXTEND_MAPSIZE;
rc = MDBX_UNABLE_EXTEND_MAPSIZE; case EEXIST: /* address busy */
case EINVAL: /* kernel don't support MAP_FIXED_NOREPLACE */
break;
} }
return rc;
} }
#else }
if (!may_move)
if (ptr == MAP_FAILED) {
/* unmap and map again whole region */
if (!may_move) {
/* TODO: Perhaps here it is worth to implement suspend/resume threads /* TODO: Perhaps here it is worth to implement suspend/resume threads
* and perform unmap/map as like for Windows. */ * and perform unmap/map as like for Windows. */
return MDBX_UNABLE_EXTEND_MAPSIZE; return MDBX_UNABLE_EXTEND_MAPSIZE;
}
if (unlikely(munmap(map->address, map->limit))) if (unlikely(munmap(map->address, map->limit)))
return errno; return errno;
unsigned mmap_flags = ptr = mmap(map->address, limit, mmap_prot, mmap_flags, map->fd, 0);
MAP_CONCEAL | MAP_SHARED | MAP_FILE |
(F_ISSET(flags, MDBX_UTTERLY_NOSYNC) ? MAP_NOSYNC : 0);
#ifdef MAP_FIXED
if (!may_move)
mmap_flags |= MAP_FIXED;
#endif
void *ptr =
mmap(map->address, limit,
(flags & MDBX_WRITEMAP) ? PROT_READ | PROT_WRITE : PROT_READ,
mmap_flags, map->fd, 0);
if (unlikely(ptr == MAP_FAILED)) { if (unlikely(ptr == MAP_FAILED)) {
ptr = mmap(map->address, map->limit, ptr = mmap(map->address, map->limit, mmap_prot, mmap_flags, map->fd, 0);
(flags & MDBX_WRITEMAP) ? PROT_READ | PROT_WRITE : PROT_READ,
mmap_flags, map->fd, 0);
if (unlikely(ptr == MAP_FAILED)) { if (unlikely(ptr == MAP_FAILED)) {
VALGRIND_MAKE_MEM_NOACCESS(map->address, map->current); VALGRIND_MAKE_MEM_NOACCESS(map->address, map->current);
/* Unpoisoning is required for ASAN to avoid false-positive diagnostic /* Unpoisoning is required for ASAN to avoid false-positive diagnostic
@ -1640,34 +1682,36 @@ retry_mapview:;
map->address = nullptr; map->address = nullptr;
return errno; return errno;
} }
return MDBX_UNABLE_EXTEND_MAPSIZE; rc = MDBX_UNABLE_EXTEND_MAPSIZE;
limit = map->limit;
} }
#endif /* !MREMAP_MAYMOVE */ }
if (map->address != ptr) { assert(ptr && ptr != MAP_FAILED);
VALGRIND_MAKE_MEM_NOACCESS(map->address, map->current); if (map->address != ptr) {
/* Unpoisoning is required for ASAN to avoid false-positive diagnostic VALGRIND_MAKE_MEM_NOACCESS(map->address, map->current);
* when this memory will re-used by malloc or another mmaping. /* Unpoisoning is required for ASAN to avoid false-positive diagnostic
* See https://github.com/erthink/libmdbx/pull/93#issuecomment-613687203 * when this memory will re-used by malloc or another mmaping.
*/ * See https://github.com/erthink/libmdbx/pull/93#issuecomment-613687203
ASAN_UNPOISON_MEMORY_REGION(map->address, map->limit); */
ASAN_UNPOISON_MEMORY_REGION(map->address, map->limit);
VALGRIND_MAKE_MEM_DEFINED(ptr, map->current); VALGRIND_MAKE_MEM_DEFINED(ptr, map->current);
ASAN_UNPOISON_MEMORY_REGION(ptr, map->current); ASAN_UNPOISON_MEMORY_REGION(ptr, map->current);
map->address = ptr; map->address = ptr;
} }
map->limit = limit; map->limit = limit;
#ifdef MADV_DONTFORK #ifdef MADV_DONTFORK
if (unlikely(madvise(map->address, map->limit, MADV_DONTFORK) != 0)) if (unlikely(madvise(map->address, map->limit, MADV_DONTFORK) != 0))
return errno; return errno;
#endif /* MADV_DONTFORK */ #endif /* MADV_DONTFORK */
#ifdef MADV_NOHUGEPAGE #ifdef MADV_NOHUGEPAGE
(void)madvise(map->address, map->limit, MADV_NOHUGEPAGE); (void)madvise(map->address, map->limit, MADV_NOHUGEPAGE);
#endif /* MADV_NOHUGEPAGE */ #endif /* MADV_NOHUGEPAGE */
}
#endif #endif /* POSIX / Windows */
return rc; return rc;
} }