nfs: make nfs_path() work without vfsmount
part 3: now we have everything to get nfs_path() just by dentry -
just follow to (disconnected) root and pick the rest of the thing
there.
Start killing propagation of struct vfsmount * on the paths that
used to bring it to nfs_path().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index f32b860..859cdab 100644
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -25,33 +25,31 @@
static DECLARE_DELAYED_WORK(nfs_automount_task, nfs_expire_automounts);
int nfs_mountpoint_expiry_timeout = 500 * HZ;
-static struct vfsmount *nfs_do_submount(const struct vfsmount *mnt_parent,
- const struct dentry *dentry,
+static struct vfsmount *nfs_do_submount(struct super_block *sb,
+ struct dentry *dentry,
struct nfs_fh *fh,
struct nfs_fattr *fattr);
/*
* nfs_path - reconstruct the path given an arbitrary dentry
- * @base - arbitrary string to prepend to the path
- * @droot - pointer to root dentry for mountpoint
+ * @base - used to return pointer to the end of devname part of path
* @dentry - pointer to dentry
* @buffer - result buffer
* @buflen - length of buffer
*
- * Helper function for constructing the path from the
- * root dentry to an arbitrary hashed dentry.
+ * Helper function for constructing the server pathname
+ * by arbitrary hashed dentry.
*
* This is mainly for use in figuring out the path on the
- * server side when automounting on top of an existing partition.
+ * server side when automounting on top of an existing partition
+ * and in generating /proc/mounts and friends.
*/
-char *nfs_path(const char *base,
- const struct dentry *droot,
- const struct dentry *dentry,
- char *buffer, ssize_t buflen)
+char *nfs_path(char **p, struct dentry *dentry, char *buffer, ssize_t buflen)
{
char *end;
int namelen;
unsigned seq;
+ const char *base;
rename_retry:
end = buffer+buflen;
@@ -60,7 +58,10 @@
seq = read_seqbegin(&rename_lock);
rcu_read_lock();
- while (!IS_ROOT(dentry) && dentry != droot) {
+ while (1) {
+ spin_lock(&dentry->d_lock);
+ if (IS_ROOT(dentry))
+ break;
namelen = dentry->d_name.len;
buflen -= namelen + 1;
if (buflen < 0)
@@ -68,27 +69,47 @@
end -= namelen;
memcpy(end, dentry->d_name.name, namelen);
*--end = '/';
+ spin_unlock(&dentry->d_lock);
dentry = dentry->d_parent;
}
- rcu_read_unlock();
- if (read_seqretry(&rename_lock, seq))
+ if (read_seqretry(&rename_lock, seq)) {
+ spin_unlock(&dentry->d_lock);
+ rcu_read_unlock();
goto rename_retry;
+ }
if (*end != '/') {
- if (--buflen < 0)
+ if (--buflen < 0) {
+ spin_unlock(&dentry->d_lock);
+ rcu_read_unlock();
goto Elong;
+ }
*--end = '/';
}
+ *p = end;
+ base = dentry->d_fsdata;
+ if (!base) {
+ spin_unlock(&dentry->d_lock);
+ rcu_read_unlock();
+ WARN_ON(1);
+ return end;
+ }
namelen = strlen(base);
/* Strip off excess slashes in base string */
while (namelen > 0 && base[namelen - 1] == '/')
namelen--;
buflen -= namelen;
- if (buflen < 0)
+ if (buflen < 0) {
+ spin_lock(&dentry->d_lock);
+ rcu_read_unlock();
goto Elong;
+ }
end -= namelen;
memcpy(end, base, namelen);
+ spin_unlock(&dentry->d_lock);
+ rcu_read_unlock();
return end;
Elong_unlock:
+ spin_lock(&dentry->d_lock);
rcu_read_unlock();
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
@@ -143,9 +164,9 @@
}
if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
- mnt = nfs_do_refmount(path->mnt, path->dentry);
+ mnt = nfs_do_refmount(path->mnt->mnt_sb, path->dentry);
else
- mnt = nfs_do_submount(path->mnt, path->dentry, fh, fattr);
+ mnt = nfs_do_submount(path->mnt->mnt_sb, path->dentry, fh, fattr);
if (IS_ERR(mnt))
goto out;
@@ -209,19 +230,19 @@
/**
* nfs_do_submount - set up mountpoint when crossing a filesystem boundary
- * @mnt_parent - mountpoint of parent directory
+ * @sb - superblock of parent directory
* @dentry - parent directory
* @fh - filehandle for new root dentry
* @fattr - attributes for new root inode
*
*/
-static struct vfsmount *nfs_do_submount(const struct vfsmount *mnt_parent,
- const struct dentry *dentry,
+static struct vfsmount *nfs_do_submount(struct super_block *sb,
+ struct dentry *dentry,
struct nfs_fh *fh,
struct nfs_fattr *fattr)
{
struct nfs_clone_mount mountdata = {
- .sb = mnt_parent->mnt_sb,
+ .sb = sb,
.dentry = dentry,
.fh = fh,
.fattr = fattr,
@@ -237,11 +258,11 @@
dentry->d_name.name);
if (page == NULL)
goto out;
- devname = nfs_devname(mnt_parent, dentry, page, PAGE_SIZE);
+ devname = nfs_devname(dentry, page, PAGE_SIZE);
mnt = (struct vfsmount *)devname;
if (IS_ERR(devname))
goto free_page;
- mnt = nfs_do_clone_mount(NFS_SB(mnt_parent->mnt_sb), devname, &mountdata);
+ mnt = nfs_do_clone_mount(NFS_SB(sb), devname, &mountdata);
free_page:
free_page((unsigned long)page);
out: