static struct ptlrpc_thread gns_thread;
static struct ll_gns_ctl gns_ctl;
+#define CONCUR_GNS_RESTART_APPROACH 0
+
/*
* waits until passed dentry gets mountpoint or timeout and attempts are
* exhausted. Returns 1 if dentry became mountpoint and 0 otherwise.
RETURN(-ETIME);
}
+#if (CONCUR_GNS_RESTART_APPROACH == 1)
+/*
+ * sending a signal known to be ignored to cause restarting syscall if GNS mount
+ * function returns -ERESTARTSYS.
+ */
+static void
+ll_gns_send_signal(void)
+{
+ struct task_struct *task = current;
+ int signal = SIGCONT;
+
+ read_lock(&tasklist_lock);
+ spin_lock_irq(&task->sighand->siglock);
+ sigaddset(&task->pending.signal, signal);
+ spin_unlock_irq(&task->sighand->siglock);
+ read_unlock(&tasklist_lock);
+ set_tsk_thread_flag(task, TIF_SIGPENDING);
+}
+#endif
+
/*
* tries to mount the mount object under passed @dentry. In the case of success
* @dentry will become mount point and 0 will be returned. Error code will be
int
ll_gns_mount_object(struct dentry *dentry, struct vfsmount *mnt)
{
- struct ll_dentry_data *lld = dentry->d_fsdata;
char *path, *pathpage, *datapage, *argv[4];
struct file *mntinfo_fd = NULL;
int cleanup_phase = 0, rc = 0;
struct dentry *dchild;
ENTRY;
+ LASSERT(dentry->d_inode != NULL);
+
+ if (!S_ISDIR(dentry->d_inode->i_mode))
+ RETURN(-EINVAL);
+
+ sbi = ll_i2sbi(dentry->d_inode);
+
if (mnt == NULL) {
CERROR("suid directory found, but no "
"vfsmount available.\n");
RETURN(-EINVAL);
}
- CDEBUG(D_INODE, "mounting dentry %p\n", dentry);
+ if (atomic_read(&sbi->ll_gns_enabled) == 0)
+ RETURN(-EINVAL);
- LASSERT(dentry->d_inode != NULL);
- LASSERT(S_ISDIR(dentry->d_inode->i_mode));
- LASSERT(lld != NULL);
-
- sbi = ll_i2sbi(dentry->d_inode);
- LASSERT(sbi != NULL);
+ spin_lock(&sbi->ll_gns_lock);
/*
* another thead is in progress or just finished mounting the
* dentry. Handling that.
*/
- spin_lock(&sbi->ll_gns_lock);
if (sbi->ll_gns_state == LL_GNS_MOUNTING ||
sbi->ll_gns_state == LL_GNS_FINISHED) {
+ /*
+ * another thread is trying to mount GNS dentry. We'd like to
+ * handling that.
+ */
spin_unlock(&sbi->ll_gns_lock);
- CDEBUG(D_INODE, "GNS is in progress now, throwing "
- "-ERESTARTSYS to restart syscall and let "
- "it finish.\n");
+
+ /*
+ * check if dentry is mount point already, if so, do not restart
+ * syscal.
+ */
+ if (d_mountpoint(dentry))
+ RETURN(0);
+
+#if (CONCUR_GNS_RESTART_APPROACH == 1)
+ /*
+ * causing syscall to restart and possibly find this dentry
+ * already mounted.
+ */
+ ll_gns_send_signal();
RETURN(-ERESTARTSYS);
+#else
+ /*
+ * waiting for GNS complete and check dentry again, it may be
+ * mounted already.
+ */
+ wait_for_completion(&sbi->ll_gns_mount_finished);
+ if (d_mountpoint(dentry))
+ RETURN(0);
+#endif
}
LASSERT(sbi->ll_gns_state == LL_GNS_IDLE);
+ CDEBUG(D_INODE, "mounting dentry %p\n", dentry);
+
/* mounting started */
sbi->ll_gns_state = LL_GNS_MOUNTING;
spin_unlock(&sbi->ll_gns_lock);
* mount object name is taken from sbi, where it is set in mount time or
* via /proc/fs... tunable. It may be ".mntinfo" or so.
*/
- dchild = lookup_one_len(sbi->ll_gns_oname, dentry,
- strlen(sbi->ll_gns_oname));
+
+ /*
+ * recursive lookup with trying to mount SUID bit marked directories on
+ * the way is not possible here, as lookup_one_len() does not pass @nd
+ * to ->lookup() and this is checked in ll_lookup_it(). So, do not
+ * handle possible -EAGAIN here.
+ */
+ dchild = ll_lookup_one_len(sbi->ll_gns_oname, dentry,
+ strlen(sbi->ll_gns_oname));
up(&sbi->ll_gns_sem);
cleanup_phase = 2;
if (IS_ERR(dchild)) {
rc = PTR_ERR(dchild);
-
- if (rc == -ERESTARTSYS) {
- CDEBUG(D_INODE, "possible endless loop is detected "
- "due to mount object is directory marked by "
- "SUID bit.\n");
- GOTO(cleanup, rc = -ELOOP);
- }
-
CERROR("can't find mount object %*s/%*s err = %d.\n",
(int)dentry->d_name.len, dentry->d_name.name,
strlen(sbi->ll_gns_oname), sbi->ll_gns_oname,
/* check if found child is regular file */
if (!S_ISREG(dchild->d_inode->i_mode))
- GOTO(cleanup, rc = -EOPNOTSUPP);
+ GOTO(cleanup, rc = -EBADF);
mntget(mnt);
GOTO(cleanup, rc);
}
+ /* no data in mount object? */
+ if (rc == 0) {
+ CERROR("mount object %*s/%*s is empty?\n",
+ (int)dentry->d_name.len, dentry->d_name.name,
+ strlen(sbi->ll_gns_oname), sbi->ll_gns_oname);
+ GOTO(cleanup, rc);
+ }
+
datapage[rc] = '\0';
fput(mntinfo_fd);
mntinfo_fd = NULL;
up(&sbi->ll_gns_sem);
- rc = USERMODEHELPER(argv[0], argv, NULL);
+ /* do not wait for helper complete here. */
+ rc = call_usermodehelper(argv[0], argv, NULL, 1);
if (rc) {
- CERROR("failed to call GNS upcall %s, err = %d\n",
- sbi->ll_gns_upcall, rc);
- GOTO(cleanup, rc);
+ CWARN("failed to call GNS upcall %s, err = %d, "
+ "checking for mount anyway\n", sbi->ll_gns_upcall, rc);
}
/*
- * wait for mount completion. This is actually not need, because
- * USERMODEHELPER() returns only when usermode process finishes. But we
- * doing this just for case USERMODEHELPER() semantics will be changed
- * or usermode upcall program will start mounting in backgound and
- * return instantly. --umka
+ * waiting for dentry become mount point GNS_WAIT_ATTEMPTS times by 1
+ * second.
*/
rc = ll_gns_wait_for_mount(dentry, 1, GNS_WAIT_ATTEMPTS);
- complete_all(&sbi->ll_gns_mount_finished);
if (rc == 0) {
struct dentry *rdentry;
struct vfsmount *rmnt;
-
- /* mount is successful */
+
LASSERT(sbi->ll_gns_state == LL_GNS_FINISHED);
rmnt = mntget(mnt);
dput(dchild);
case 1:
free_page((unsigned long)pathpage);
-
- /*
- * waking up all waiters after gns state is set to
- * LL_GNS_MOUNTING
- */
- complete_all(&sbi->ll_gns_mount_finished);
case 0:
spin_lock(&sbi->ll_gns_lock);
sbi->ll_gns_state = LL_GNS_IDLE;
spin_unlock(&sbi->ll_gns_lock);
+ complete_all(&sbi->ll_gns_mount_finished);
}
return rc;
}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff