afs: Add fsinfo support

Add fsinfo support to the AFS filesystem.

Signed-off-by: David Howells <dhowells@redhat.com>

diff --git a/fs/afs/super.c b/fs/afs/super.c
index 944985e0a3c8cff0be64949bf72385e500897b6b..1fe5026b1104afd08b7bdc00424dc5aee37e8b4d 100644 (file)
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -26,6 +26,7 @@
 #include <linux/sched.h>
 #include <linux/nsproxy.h>
 #include <linux/magic.h>
+#include <linux/fsinfo.h>
 #include <net/net_namespace.h>
 #include "internal.h"
 
@@ -34,6 +35,7 @@ static void afs_kill_super(struct super_block *sb);
 static struct inode *afs_alloc_inode(struct super_block *sb);
 static void afs_destroy_inode(struct inode *inode);
 static int afs_statfs(struct dentry *dentry, struct kstatfs *buf);
+static int afs_fsinfo(struct path *path, struct fsinfo_kparams *params);
 static int afs_show_devname(struct seq_file *m, struct dentry *root);
 static int afs_show_options(struct seq_file *m, struct dentry *root);
 static int afs_init_fs_context(struct fs_context *fc, struct dentry *reference);
@@ -53,6 +55,7 @@ int afs_net_id;
 
 static const struct super_operations afs_super_ops = {
        .statfs         = afs_statfs,
+       .fsinfo         = afs_fsinfo,
        .alloc_inode    = afs_alloc_inode,
        .drop_inode     = afs_drop_inode,
        .destroy_inode  = afs_destroy_inode,
@@ -769,3 +772,129 @@ static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
 
        return ret;
 }
+
+/*
+ * Get filesystem information.
+ */
+static int afs_fsinfo(struct path *path, struct fsinfo_kparams *params)
+{
+       struct fsinfo_timestamp_info *tsinfo;
+       struct fsinfo_server_address *addr;
+       struct fsinfo_capabilities *caps;
+       struct fsinfo_supports *sup;
+       struct dentry *dentry = path->dentry;
+       struct afs_server_list *slist;
+       struct afs_super_info *as = AFS_FS_S(dentry->d_sb);
+       struct afs_addr_list *alist;
+       struct afs_server *server;
+       struct afs_volume *volume = as->volume;
+       struct afs_cell *cell = as->cell;
+       struct afs_net *net = afs_d2net(dentry);
+       bool dyn_root = as->dyn_root;
+       int ret;
+
+       switch (params->request) {
+       case FSINFO_ATTR_TIMESTAMP_INFO:
+               tsinfo = params->buffer;
+               tsinfo->minimum_timestamp = 0;
+               tsinfo->maximum_timestamp = UINT_MAX;
+               tsinfo->mtime_gran_mantissa = 1;
+               tsinfo->mtime_gran_exponent = 0;
+               return sizeof(*tsinfo);
+
+       case FSINFO_ATTR_SUPPORTS:
+               sup = params->buffer;
+               sup->stx_mask = (STATX_TYPE | STATX_MODE |
+                                STATX_NLINK |
+                                STATX_UID | STATX_GID |
+                                STATX_MTIME | STATX_INO |
+                                STATX_SIZE);
+               sup->stx_attributes = STATX_ATTR_AUTOMOUNT;
+               return sizeof(*sup);
+
+       case FSINFO_ATTR_CAPABILITIES:
+               caps = params->buffer;
+               if (dyn_root) {
+                       fsinfo_set_cap(caps, FSINFO_CAP_IS_AUTOMOUNTER_FS);
+                       fsinfo_set_cap(caps, FSINFO_CAP_AUTOMOUNTS);
+               } else {
+                       fsinfo_set_cap(caps, FSINFO_CAP_IS_NETWORK_FS);
+                       fsinfo_set_cap(caps, FSINFO_CAP_AUTOMOUNTS);
+                       fsinfo_set_cap(caps, FSINFO_CAP_ADV_LOCKS);
+                       fsinfo_set_cap(caps, FSINFO_CAP_UIDS);
+                       fsinfo_set_cap(caps, FSINFO_CAP_GIDS);
+                       fsinfo_set_cap(caps, FSINFO_CAP_VOLUME_ID);
+                       fsinfo_set_cap(caps, FSINFO_CAP_VOLUME_NAME);
+                       fsinfo_set_cap(caps, FSINFO_CAP_CELL_NAME);
+                       fsinfo_set_cap(caps, FSINFO_CAP_IVER_MONO_INCR);
+                       fsinfo_set_cap(caps, FSINFO_CAP_SYMLINKS);
+                       fsinfo_set_cap(caps, FSINFO_CAP_HARD_LINKS_1DIR);
+                       fsinfo_set_cap(caps, FSINFO_CAP_HAS_MTIME);
+               }
+               return sizeof(*caps);
+
+       case FSINFO_ATTR_VOLUME_NAME:
+               if (dyn_root)
+                       return -EOPNOTSUPP;
+               memcpy(params->buffer, volume->name, volume->name_len);
+               return volume->name_len;
+
+       case FSINFO_ATTR_CELL_NAME:
+               if (dyn_root)
+                       return -EOPNOTSUPP;
+               memcpy(params->buffer, cell->name, cell->name_len);
+               return cell->name_len;
+
+       case FSINFO_ATTR_SERVER_NAME:
+               if (dyn_root)
+                       return -EOPNOTSUPP;
+               read_lock(&volume->servers_lock);
+               slist = afs_get_serverlist(volume->servers);
+               read_unlock(&volume->servers_lock);
+
+               if (params->Nth < slist->nr_servers) {
+                       server = slist->servers[params->Nth].server;
+                       ret = sprintf(params->buffer, "%pU", &server->uuid);
+               } else {
+                       ret = -ENODATA;
+               }
+
+               afs_put_serverlist(net, slist);
+               return ret;
+
+       case FSINFO_ATTR_SERVER_ADDRESS:
+               addr = params->buffer;
+               if (dyn_root)
+                       return -EOPNOTSUPP;
+               read_lock(&volume->servers_lock);
+               slist = afs_get_serverlist(volume->servers);
+               read_unlock(&volume->servers_lock);
+
+               ret = -ENODATA;
+               if (params->Nth >= slist->nr_servers)
+                       goto put_slist;
+               server = slist->servers[params->Nth].server;
+
+               read_lock(&server->fs_lock);
+               alist = afs_get_addrlist(rcu_access_pointer(server->addresses));
+               read_unlock(&server->fs_lock);
+               if (!alist)
+                       goto put_slist;
+
+               if (params->Mth >= alist->nr_addrs)
+                       goto put_alist;
+
+               memcpy(addr, &alist->addrs[params->Mth],
+                      sizeof(struct sockaddr_rxrpc));
+               ret = sizeof(*addr);
+
+       put_alist:
+               afs_put_addrlist(alist);
+       put_slist:
+               afs_put_serverlist(net, slist);
+               return ret;
+
+       default:
+               return generic_fsinfo(path, params);
+       }
+}