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| author | Narayanan V <v.narayanan@sun.com> | 2009-04-09 13:48:23 +0530 |
|---|---|---|
| committer | Narayanan V <v.narayanan@sun.com> | 2009-04-09 13:48:23 +0530 |
| commit | 9b1076b4717e470c6b9391441a1016b402053541 (patch) | |
| tree | 00988a6e771a7d0c6ab578e5c6abc1aeb3e747bc /storage/myisam | |
| parent | b745d02a030cb65c32817fdac539dbac32d6718b (diff) | |
| download | mariadb-git-9b1076b4717e470c6b9391441a1016b402053541.tar.gz | |
Bug#38848 myisam_use_mmap causes widespread myisam corruption on windows
Currently the memory map is being created
with a size that is greater than the size
of the underlying datafile. This can cause
varying behaviour,
e.g.
In windows the size of the datafile
is increased, while on linux it remains
the same.
This fix removes the increment margin to
the size that is used while creating the
memory map.
Diffstat (limited to 'storage/myisam')
| -rw-r--r-- | storage/myisam/mi_dynrec.c | 6 | ||||
| -rw-r--r-- | storage/myisam/mi_packrec.c | 4 |
2 files changed, 6 insertions, 4 deletions
diff --git a/storage/myisam/mi_dynrec.c b/storage/myisam/mi_dynrec.c index 3433c26f98b..d1cbd6955dd 100644 --- a/storage/myisam/mi_dynrec.c +++ b/storage/myisam/mi_dynrec.c @@ -66,7 +66,7 @@ static int _mi_cmp_buffer(File file, const uchar *buff, my_off_t filepos, my_bool mi_dynmap_file(MI_INFO *info, my_off_t size) { DBUG_ENTER("mi_dynmap_file"); - if (size > (my_off_t) (~((size_t) 0)) - MEMMAP_EXTRA_MARGIN) + if (size > (my_off_t) (~((size_t) 0))) { DBUG_PRINT("warning", ("File is too large for mmap")); DBUG_RETURN(1); @@ -80,7 +80,7 @@ my_bool mi_dynmap_file(MI_INFO *info, my_off_t size) upon a write if no physical memory is available. */ info->s->file_map= (uchar*) - my_mmap(0, (size_t)(size + MEMMAP_EXTRA_MARGIN), + my_mmap(0, (size_t) size, info->s->mode==O_RDONLY ? PROT_READ : PROT_READ | PROT_WRITE, MAP_SHARED | MAP_NORESERVE, @@ -113,7 +113,7 @@ void mi_remap_file(MI_INFO *info, my_off_t size) if (info->s->file_map) { VOID(my_munmap((char*) info->s->file_map, - (size_t) info->s->mmaped_length + MEMMAP_EXTRA_MARGIN)); + (size_t) info->s->mmaped_length)); mi_dynmap_file(info, size); } } diff --git a/storage/myisam/mi_packrec.c b/storage/myisam/mi_packrec.c index be9ce9a0c24..d9abcbce050 100644 --- a/storage/myisam/mi_packrec.c +++ b/storage/myisam/mi_packrec.c @@ -1502,7 +1502,9 @@ my_bool _mi_memmap_file(MI_INFO *info) DBUG_PRINT("warning",("File isn't extended for memmap")); DBUG_RETURN(0); } - if (mi_dynmap_file(info, share->state.state.data_file_length)) + if (mi_dynmap_file(info, + share->state.state.data_file_length + + MEMMAP_EXTRA_MARGIN)) DBUG_RETURN(0); } info->opt_flag|= MEMMAP_USED; |