[PATCH v4 03/26] nfs: lift setting mount_info from nfs4_remote{,_referral}_mount

Scott Mayhew
2019-09-13T12:19:28Z

Do that (fhandle allocation, setting struct server up) in
nfs4_referral_mount() and nfs4_try_mount() resp. and pass the
server and pointer to mount_info into nfs_do_root_mount() so that
nfs4_remote_referral_mount()/nfs_remote_mount() could be merged.

Since we are moving stuff from ->mount() instances to the points
prior to vfs_kern_mount() that would trigger those, we need to
make sure that do_nfs_root_mount() will do the corresponding
cleanup itself if it doesn't trigger those ->mount() instances.

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/nfs/nfs4super.c | 67 ++++++++++++++++++++++++----------------------
1 file changed, 35 insertions(+), 32 deletions(-)

diff --git a/fs/nfs/nfs4super.c b/fs/nfs/nfs4super.c
index 4591d6618efa..773c347df3ab 100644
--- a/fs/nfs/nfs4super.c
+++ b/fs/nfs/nfs4super.c
@@ -108,32 +108,37 @@ static struct dentry *
nfs4_remote_mount(struct file_system_type *fs_type, int flags,
const char *dev_name, void *info)
{
- struct nfs_mount_info *mount_info = info;
-
- mount_info->set_security = nfs_set_sb_security;
-
- /* Get a volume representation */
- mount_info->server = nfs4_create_server(mount_info, &nfs_v4);
- return nfs_fs_mount_common(flags, dev_name, mount_info, &nfs_v4);
+ return nfs_fs_mount_common(flags, dev_name, info, &nfs_v4);
}

static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
- int flags, void *data, const char *hostname)
+ struct nfs_server *server, int flags,
+ struct nfs_mount_info *info,
+ const char *hostname)
{
struct vfsmount *root_mnt;
char *root_devname;
size_t len;

+ if (IS_ERR(server))
+ return ERR_CAST(server);
+
len = strlen(hostname) + 5;
root_devname = kmalloc(len, GFP_KERNEL);
- if (root_devname == NULL)
+ if (root_devname == NULL) {
+ nfs_free_server(server);
return ERR_PTR(-ENOMEM);
+ }
/* Does hostname needs to be enclosed in brackets? */
if (strchr(hostname, ':'))
snprintf(root_devname, len, "[%s]:/", hostname);
else
snprintf(root_devname, len, "%s:/", hostname);
- root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
+ info->server = server;
+ root_mnt = vfs_kern_mount(fs_type, flags, root_devname, info);
+ if (info->server)
+ nfs_free_server(info->server);
+ info->server = NULL;
kfree(root_devname);
return root_mnt;
}
@@ -234,11 +239,15 @@ struct dentry *nfs4_try_mount(int flags, const char *dev_name,
struct dentry *res;
struct nfs_parsed_mount_data *data = mount_info->parsed;

+ mount_info->set_security = nfs_set_sb_security;
+
dfprintk(MOUNT, "--> nfs4_try_mount()\n");

export_path = data->nfs_server.export_path;
data->nfs_server.export_path = "/";
- root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, mount_info,
+ root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type,
+ nfs4_create_server(mount_info, &nfs_v4),
+ flags, mount_info,
data->nfs_server.hostname);
data->nfs_server.export_path = export_path;

@@ -254,25 +263,7 @@ static struct dentry *
nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
const char *dev_name, void *raw_data)
{
- struct nfs_mount_info mount_info = {
- .fill_super = nfs_fill_super,
- .set_security = nfs_clone_sb_security,
- .cloned = raw_data,
- };
- struct dentry *mntroot = ERR_PTR(-ENOMEM);
-
- dprintk("--> nfs4_referral_get_sb()\n");
-
- mount_info.mntfh = nfs_alloc_fhandle();
- if (mount_info.cloned == NULL || mount_info.mntfh == NULL)
- goto out;
-
- /* create a new volume representation */
- mount_info.server = nfs4_create_referral_server(mount_info.cloned, mount_info.mntfh);
- mntroot = nfs_fs_mount_common(flags, dev_name, &mount_info, &nfs_v4);
-out:
- nfs_free_fhandle(mount_info.mntfh);
- return mntroot;
+ return nfs_fs_mount_common(flags, dev_name, raw_data, &nfs_v4);
}

/*
@@ -282,23 +273,35 @@ static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *raw_data)
{
struct nfs_clone_mount *data = raw_data;
+ struct nfs_mount_info mount_info = {
+ .fill_super = nfs_fill_super,
+ .set_security = nfs_clone_sb_security,
+ .cloned = data,
+ };
char *export_path;
struct vfsmount *root_mnt;
struct dentry *res;

dprintk("--> nfs4_referral_mount()\n");

+ mount_info.mntfh = nfs_alloc_fhandle();
+ if (!mount_info.mntfh)
+ return ERR_PTR(-ENOMEM);
+
export_path = data->mnt_path;
data->mnt_path = "/";
-
root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
- flags, data, data->hostname);
+ nfs4_create_referral_server(mount_info.cloned,
+ mount_info.mntfh),
+ flags, &mount_info, data->hostname);
data->mnt_path = export_path;

res = nfs_follow_remote_path(root_mnt, export_path);
dprintk("<-- nfs4_referral_mount() = %d%s\n",
PTR_ERR_OR_ZERO(res),
IS_ERR(res) ? " [error]" : "");
+
+ nfs_free_fhandle(mount_info.mntfh);
return res;
}

--
2.17.2