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| author | Alasdair G Kergon <agk@redhat.com> | 2011-10-31 20:19:04 +0000 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2011-10-31 20:19:04 +0000 |
| commit | 36a0456fbf2d9680bf9af81b39daf4a8e22cb1b8 (patch) | |
| tree | a19af18640d538e8357c195e6b4c77d0f6c92391 /drivers/md/dm-ioctl.c | |
| parent | cc6cbe141a20f6d876b161b60af38d93935bfa85 (diff) | |
| download | lwn-36a0456fbf2d9680bf9af81b39daf4a8e22cb1b8.tar.gz lwn-36a0456fbf2d9680bf9af81b39daf4a8e22cb1b8.zip | |
dm table: add immutable feature
Introduce DM_TARGET_IMMUTABLE to indicate that the target type cannot be mixed
with any other target type, and once loaded into a device, it cannot be
replaced with a table containing a different type.
The thin provisioning pool device will use this.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md/dm-ioctl.c')
| -rw-r--r-- | drivers/md/dm-ioctl.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 2e9a3ca37bdd..31c2dc25886d 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1215,6 +1215,7 @@ static int table_load(struct dm_ioctl *param, size_t param_size) struct hash_cell *hc; struct dm_table *t; struct mapped_device *md; + struct target_type *immutable_target_type; md = find_device(param); if (!md) @@ -1230,6 +1231,16 @@ static int table_load(struct dm_ioctl *param, size_t param_size) goto out; } + immutable_target_type = dm_get_immutable_target_type(md); + if (immutable_target_type && + (immutable_target_type != dm_table_get_immutable_target_type(t))) { + DMWARN("can't replace immutable target type %s", + immutable_target_type->name); + dm_table_destroy(t); + r = -EINVAL; + goto out; + } + /* Protect md->type and md->queue against concurrent table loads. */ dm_lock_md_type(md); if (dm_get_md_type(md) == DM_TYPE_NONE) |