/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=8:tabstop=8:
*
- * Copyright (C) 2004 Cluster File Systems, Inc.
- * Author: Phil Schwan <phil@clusterfs.com>
+ * Copyright (C) 2004, 2005 Cluster File Systems, Inc.
+ *
+ * Author: Phil Schwan <phil@clusterfs.com>
+ * Author: Oleg Drokin <green@clusterfs.com>
+ * Author: Yury Umanets <yury@clusterfs.com>
+ * Review: Nikita Danilov <nikita@clusterfs.com>
*
* This file is part of Lustre, http://www.lustre.org.
*
{
struct l_wait_info lwi;
struct ll_sb_info *sbi;
- int rc;
ENTRY;
LASSERT(dentry != NULL);
LASSERT(!IS_ERR(dentry));
sbi = ll_s2sbi(dentry->d_sb);
- for (; !d_mountpoint(dentry) && tries > 0; tries--) {
- lwi = LWI_TIMEOUT(timeout * HZ, NULL, NULL);
+ lwi = LWI_TIMEOUT(timeout * HZ, NULL, NULL);
+ for (; !d_mountpoint(dentry) && tries > 0; tries--)
l_wait_event(sbi->ll_gns_waitq, d_mountpoint(dentry), &lwi);
- }
- if ((rc = d_mountpoint(dentry) ? 1 : 0)) {
+ if (d_mountpoint(dentry)) {
spin_lock(&sbi->ll_gns_lock);
- LASSERT(sbi->ll_gns_state == LL_GNS_MOUNTING);
sbi->ll_gns_state = LL_GNS_FINISHED;
spin_unlock(&sbi->ll_gns_lock);
+ RETURN(0);
}
-
- complete(&sbi->ll_gns_mount_finished);
- RETURN(rc);
+ RETURN(-ETIME);
}
/*
* tries to mount the mount object under passed @dentry. In the case of success
- * @dentry will become mount point and 0 will be retuned. Error code will be
+ * @dentry will become mount point and 0 will be returned. Error code will be
* returned otherwise.
*/
-int ll_gns_mount_object(struct dentry *dentry,
- struct vfsmount *mnt)
+int
+ll_gns_mount_object(struct dentry *dentry, struct vfsmount *mnt)
{
struct ll_dentry_data *lld = dentry->d_fsdata;
- char *p, *path, *pathpage, *argv[4];
+ char *path, *pathpage, *datapage, *argv[4];
struct file *mntinfo_fd = NULL;
- struct address_space *mapping;
int cleanup_phase = 0, rc = 0;
struct ll_sb_info *sbi;
struct dentry *dchild;
- struct page *datapage;
- filler_t *filler;
ENTRY;
if (mnt == NULL) {
sbi = ll_i2sbi(dentry->d_inode);
LASSERT(sbi != NULL);
- /* another thead is in progress of mouning some entry */
+ /*
+ * 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) {
+ if (sbi->ll_gns_state == LL_GNS_MOUNTING ||
+ sbi->ll_gns_state == LL_GNS_FINISHED) {
spin_unlock(&sbi->ll_gns_lock);
-
- wait_for_completion(&sbi->ll_gns_mount_finished);
- if (d_mountpoint(dentry))
- RETURN(0);
- }
-
- /* another thread mounted it already */
- if (sbi->ll_gns_state == LL_GNS_FINISHED) {
- spin_unlock(&sbi->ll_gns_lock);
-
- /* we lost a race; just return */
- if (d_mountpoint(dentry))
- RETURN(0);
+ CDEBUG(D_INODE, "GNS is in progress now, throwing "
+ "-ERESTARTSYS to restart syscall and let "
+ "it finish.\n");
+ RETURN(-ERESTARTSYS);
}
LASSERT(sbi->ll_gns_state == LL_GNS_IDLE);
GOTO(cleanup, rc = PTR_ERR(dchild));
}
- /* sychronizing with possible /proc/fs/...write */
+ /* synchronizing with possible /proc/fs/...write */
down(&sbi->ll_gns_sem);
/*
* 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 = ll_d_lookup(sbi->ll_gns_oname, dentry,
- strlen(sbi->ll_gns_oname));
+
+ /*
+ * FIXME: lookup_one_len() requires dentry->d_inode->i_sem to be locked,
+ * but we can't use ll_lookup_one_len() as this function is called from
+ * different contol paths and some of them take dentry->d_inode->i_sem
+ * and others do not.
+ */
+ dchild = lookup_one_len(sbi->ll_gns_oname, dentry,
+ strlen(sbi->ll_gns_oname));
up(&sbi->ll_gns_sem);
- if (!dchild)
- GOTO(cleanup, rc = -ENOENT);
+ 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,
- (int)dchild->d_name.len, dchild->d_name.name,
- (int)PTR_ERR(dchild));
- GOTO(cleanup, rc = PTR_ERR(dchild));
+ strlen(sbi->ll_gns_oname), sbi->ll_gns_oname,
+ rc);
+ GOTO(cleanup, rc);
}
+ /* mount object is not found */
+ if (!dchild->d_inode)
+ GOTO(cleanup, rc = -ENOENT);
+
+ /* check if found child is regular file */
+ if (!S_ISREG(dchild->d_inode->i_mode))
+ GOTO(cleanup, rc = -EOPNOTSUPP);
+
mntget(mnt);
/* ok, mount object if found, opening it. */
if (IS_ERR(mntinfo_fd)) {
CERROR("can't open mount object %*s/%*s err = %d.\n",
(int)dentry->d_name.len, dentry->d_name.name,
- (int)dchild->d_name.len, dchild->d_name.name,
+ strlen(sbi->ll_gns_oname), sbi->ll_gns_oname,
(int)PTR_ERR(mntinfo_fd));
- dput(dchild);
mntput(mnt);
GOTO(cleanup, rc = PTR_ERR(mntinfo_fd));
}
- cleanup_phase = 2;
+ cleanup_phase = 3;
if (mntinfo_fd->f_dentry->d_inode->i_size > PAGE_SIZE) {
CERROR("mount object %*s/%*s is too big (%Ld)\n",
(int)dentry->d_name.len, dentry->d_name.name,
- (int)dchild->d_name.len, dchild->d_name.name,
+ strlen(sbi->ll_gns_oname), sbi->ll_gns_oname,
mntinfo_fd->f_dentry->d_inode->i_size);
GOTO(cleanup, rc = -EFBIG);
}
+ datapage = (char *)__get_free_page(GFP_KERNEL);
+ if (!datapage)
+ GOTO(cleanup, rc = -ENOMEM);
+
+ cleanup_phase = 4;
+
/* read data from mount object. */
- mapping = mntinfo_fd->f_dentry->d_inode->i_mapping;
- filler = (filler_t *)mapping->a_ops->readpage;
- datapage = read_cache_page(mapping, 0, filler,
- mntinfo_fd);
- if (IS_ERR(datapage)) {
- CERROR("can't read data from mount object %*s/%*s\n",
+ rc = kernel_read(mntinfo_fd, 0, datapage, PAGE_SIZE);
+ if (rc < 0) {
+ CERROR("can't read mount object %*s/%*s data, err %d\n",
(int)dentry->d_name.len, dentry->d_name.name,
- (int)dchild->d_name.len, dchild->d_name.name);
- GOTO(cleanup, rc = PTR_ERR(datapage));
+ strlen(sbi->ll_gns_oname), sbi->ll_gns_oname,
+ rc);
+ GOTO(cleanup, rc);
}
- p = kmap(datapage);
- LASSERT(p != NULL);
- p[PAGE_SIZE - 1] = '\0';
- cleanup_phase = 3;
+ datapage[PAGE_SIZE - 1] = '\0';
fput(mntinfo_fd);
mntinfo_fd = NULL;
+ dchild = NULL;
- /* sychronizing with possible /proc/fs/...write */
+ /* synchronizing with possible /proc/fs/...write */
down(&sbi->ll_gns_sem);
/*
* may be /usr/lib/lustre/gns-upcall.sh
*/
argv[0] = sbi->ll_gns_upcall;
- argv[1] = p;
+ argv[1] = datapage;
argv[2] = path;
argv[3] = NULL;
/*
* 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() semanthics will be changed
+ * doing this just for case USERMODEHELPER() semantics will be changed
* or usermode upcall program will start mounting in backgound and
* return instantly. --umka
*/
- if (ll_gns_wait_for_mount(dentry, 1, GNS_WAIT_ATTEMPTS)) {
+ 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;
dentry->d_flags &= ~DCACHE_GNS_PENDING;
spin_unlock(&dentry->d_lock);
} else {
- CERROR("usermode upcall %s failed to mount %s\n",
- sbi->ll_gns_upcall, path);
- rc = -ETIME;
+ CERROR("usermode upcall %s failed to mount %s, err %d\n",
+ sbi->ll_gns_upcall, path, rc);
}
-
+
EXIT;
cleanup:
switch (cleanup_phase) {
+ case 4:
+ free_page((unsigned long)datapage);
case 3:
- kunmap(datapage);
- page_cache_release(datapage);
- case 2:
if (mntinfo_fd != NULL)
fput(mntinfo_fd);
+ case 2:
+ if (dchild != NULL)
+ 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;
}
/*
- * GNS timer callback function. It restarts gns timer and wakes up GNS cvontrol
+ * GNS timer callback function. It restarts gns timer and wakes up GNS control
* thread to process mounts list.
*/
void ll_gns_timer_callback(unsigned long data)
return rc;
}
-/* should we staop GNS control thread? */
+/* should we stop GNS control thread? */
static int inline ll_gns_check_stop(void)
{
mb();
spin_unlock(&gns_lock);
}
- /*
- * letting know stop function know that thread is stoped and it may
- * return.
- */
EXIT;
gns_thread.t_flags = SVC_STOPPED;
git://git.whamcloud.com / fs / lustre-release.git / blobdiff