diff options
| -rw-r--r-- | fs/nfs/super.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 614efeed543..b550e921f66 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -207,6 +207,7 @@ static int nfs_xdev_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt); static void nfs_kill_super(struct super_block *); static void nfs_put_super(struct super_block *); +static int nfs_remount(struct super_block *sb, int *flags, char *raw_data); static struct file_system_type nfs_fs_type = { .owner = THIS_MODULE, @@ -234,6 +235,7 @@ static const struct super_operations nfs_sops = { .umount_begin = nfs_umount_begin, .show_options = nfs_show_options, .show_stats = nfs_show_stats, + .remount_fs = nfs_remount, }; #ifdef CONFIG_NFS_V4 @@ -278,6 +280,7 @@ static const struct super_operations nfs4_sops = { .umount_begin = nfs_umount_begin, .show_options = nfs_show_options, .show_stats = nfs_show_stats, + .remount_fs = nfs_remount, }; #endif @@ -1396,6 +1399,79 @@ out_invalid_fh: return -EINVAL; } +static int +nfs_compare_remount_data(struct nfs_server *nfss, + struct nfs_parsed_mount_data *data) +{ + if (data->flags != nfss->flags || + data->rsize != nfss->rsize || + data->wsize != nfss->wsize || + data->retrans != nfss->client->cl_timeout->to_retries || + data->auth_flavors[0] != nfss->client->cl_auth->au_flavor || + data->acregmin != nfss->acregmin / HZ || + data->acregmax != nfss->acregmax / HZ || + data->acdirmin != nfss->acdirmin / HZ || + data->acdirmax != nfss->acdirmax / HZ || + data->timeo != (10U * nfss->client->cl_timeout->to_initval / HZ) || + data->nfs_server.addrlen != nfss->nfs_client->cl_addrlen || + memcmp(&data->nfs_server.address, &nfss->nfs_client->cl_addr, + data->nfs_server.addrlen) != 0) + return -EINVAL; + + return 0; +} + +static int +nfs_remount(struct super_block *sb, int *flags, char *raw_data) +{ + int error; + struct nfs_server *nfss = sb->s_fs_info; + struct nfs_parsed_mount_data *data; + struct nfs_mount_data *options = (struct nfs_mount_data *)raw_data; + struct nfs4_mount_data *options4 = (struct nfs4_mount_data *)raw_data; + + /* + * Userspace mount programs that send binary options generally send + * them populated with default values. We have no way to know which + * ones were explicitly specified. Fall back to legacy behavior and + * just return success. + */ + if ((sb->s_type == &nfs4_fs_type && options4->version == 1) || + (sb->s_type == &nfs_fs_type && options->version >= 1 && + options->version <= 6)) + return 0; + + data = kzalloc(sizeof(*data), GFP_KERNEL); + if (data == NULL) + return -ENOMEM; + + /* fill out struct with values from existing mount */ + data->flags = nfss->flags; + data->rsize = nfss->rsize; + data->wsize = nfss->wsize; + data->retrans = nfss->client->cl_timeout->to_retries; + data->auth_flavors[0] = nfss->client->cl_auth->au_flavor; + data->acregmin = nfss->acregmin / HZ; + data->acregmax = nfss->acregmax / HZ; + data->acdirmin = nfss->acdirmin / HZ; + data->acdirmax = nfss->acdirmax / HZ; + data->timeo = 10U * nfss->client->cl_timeout->to_initval / HZ; + data->nfs_server.addrlen = nfss->nfs_client->cl_addrlen; + memcpy(&data->nfs_server.address, &nfss->nfs_client->cl_addr, + data->nfs_server.addrlen); + + /* overwrite those values with any that were specified */ + error = nfs_parse_mount_options((char *)options, data); + if (error < 0) + goto out; + + /* compare new mount options with old ones */ + error = nfs_compare_remount_data(nfss, data); +out: + kfree(data); + return error; +} + /* * Initialise the common bits of the superblock */ |