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authorPatrick Caulfield <pcaulfie@redhat.com>2007-03-21 09:23:53 +0000
committerSteven Whitehouse <swhiteho@redhat.com>2007-05-01 09:10:44 +0100
commit254da030dfb1b13d42d07e4292a4790d88c6874f (patch)
tree8c8f34d6b33232f8081fff6842930d55b2b41140 /fs/dlm/user.c
parent420d2a1028b906f24e836e37089a6ad55ab1848f (diff)
[DLM] Don't delete misc device if lockspace removal fails
Currently if the lockspace removal fails the misc device associated with a lockspace is left deleted. After that there is no way to access the orphaned lockspace from userland. This patch recreates the misc device if th dlm_release_lockspace fails. I believe this is better than attempting to remove the lockspace first because that leaves an unattached device lying around. The potential gap in which there is no access to the lockspace between removing the misc device and recreating it is acceptable ... after all the application is trying to remove it, and only new users of the lockspace will be affected. Signed-Off-By: Patrick Caulfield <pcaulfie@redhat.com> Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/dlm/user.c')
-rw-r--r--fs/dlm/user.c58
1 files changed, 36 insertions, 22 deletions
diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index 3870150b83a..27a75ce571c 100644
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -286,11 +286,34 @@ static int device_user_unlock(struct dlm_user_proc *proc,
return error;
}
+static int create_misc_device(struct dlm_ls *ls, char *name)
+{
+ int error, len;
+
+ error = -ENOMEM;
+ len = strlen(name) + strlen(name_prefix) + 2;
+ ls->ls_device.name = kzalloc(len, GFP_KERNEL);
+ if (!ls->ls_device.name)
+ goto fail;
+
+ snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix,
+ name);
+ ls->ls_device.fops = &device_fops;
+ ls->ls_device.minor = MISC_DYNAMIC_MINOR;
+
+ error = misc_register(&ls->ls_device);
+ if (error) {
+ kfree(ls->ls_device.name);
+ }
+fail:
+ return error;
+}
+
static int device_create_lockspace(struct dlm_lspace_params *params)
{
dlm_lockspace_t *lockspace;
struct dlm_ls *ls;
- int error, len;
+ int error;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
@@ -304,29 +327,14 @@ static int device_create_lockspace(struct dlm_lspace_params *params)
if (!ls)
return -ENOENT;
- error = -ENOMEM;
- len = strlen(params->name) + strlen(name_prefix) + 2;
- ls->ls_device.name = kzalloc(len, GFP_KERNEL);
- if (!ls->ls_device.name)
- goto fail;
- snprintf((char *)ls->ls_device.name, len, "%s_%s", name_prefix,
- params->name);
- ls->ls_device.fops = &device_fops;
- ls->ls_device.minor = MISC_DYNAMIC_MINOR;
-
- error = misc_register(&ls->ls_device);
- if (error) {
- kfree(ls->ls_device.name);
- goto fail;
- }
-
- error = ls->ls_device.minor;
+ error = create_misc_device(ls, params->name);
dlm_put_lockspace(ls);
- return error;
- fail:
- dlm_put_lockspace(ls);
- dlm_release_lockspace(lockspace, 0);
+ if (error)
+ dlm_release_lockspace(lockspace, 0);
+ else
+ error = ls->ls_device.minor;
+
return error;
}
@@ -343,6 +351,10 @@ static int device_remove_lockspace(struct dlm_lspace_params *params)
if (!ls)
return -ENOENT;
+ /* Deregister the misc device first, so we don't have
+ * a device that's not attached to a lockspace. If
+ * dlm_release_lockspace fails then we can recreate it
+ */
error = misc_deregister(&ls->ls_device);
if (error) {
dlm_put_lockspace(ls);
@@ -361,6 +373,8 @@ static int device_remove_lockspace(struct dlm_lspace_params *params)
dlm_put_lockspace(ls);
error = dlm_release_lockspace(lockspace, force);
+ if (error)
+ create_misc_device(ls, ls->ls_name);
out:
return error;
}