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-rw-r--r--fs/afs/super.c778
1 files changed, 778 insertions, 0 deletions
diff --git a/fs/afs/super.c b/fs/afs/super.c
new file mode 100644
index 000000000..e95fb4cb4
--- /dev/null
+++ b/fs/afs/super.c
@@ -0,0 +1,778 @@
+/* AFS superblock handling
+ *
+ * Copyright (c) 2002, 2007, 2018 Red Hat, Inc. All rights reserved.
+ *
+ * This software may be freely redistributed under the terms of the
+ * GNU General Public License.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Authors: David Howells <dhowells@redhat.com>
+ * David Woodhouse <dwmw2@infradead.org>
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mount.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/fs_parser.h>
+#include <linux/statfs.h>
+#include <linux/sched.h>
+#include <linux/nsproxy.h>
+#include <linux/magic.h>
+#include <net/net_namespace.h>
+#include "internal.h"
+
+static void afs_i_init_once(void *foo);
+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 void afs_free_inode(struct inode *inode);
+static int afs_statfs(struct dentry *dentry, struct kstatfs *buf);
+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);
+static const struct fs_parameter_spec afs_fs_parameters[];
+
+struct file_system_type afs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "afs",
+ .init_fs_context = afs_init_fs_context,
+ .parameters = afs_fs_parameters,
+ .kill_sb = afs_kill_super,
+ .fs_flags = FS_RENAME_DOES_D_MOVE,
+};
+MODULE_ALIAS_FS("afs");
+
+int afs_net_id;
+
+static const struct super_operations afs_super_ops = {
+ .statfs = afs_statfs,
+ .alloc_inode = afs_alloc_inode,
+ .write_inode = afs_write_inode,
+ .drop_inode = afs_drop_inode,
+ .destroy_inode = afs_destroy_inode,
+ .free_inode = afs_free_inode,
+ .evict_inode = afs_evict_inode,
+ .show_devname = afs_show_devname,
+ .show_options = afs_show_options,
+};
+
+static struct kmem_cache *afs_inode_cachep;
+static atomic_t afs_count_active_inodes;
+
+enum afs_param {
+ Opt_autocell,
+ Opt_dyn,
+ Opt_flock,
+ Opt_source,
+};
+
+static const struct constant_table afs_param_flock[] = {
+ {"local", afs_flock_mode_local },
+ {"openafs", afs_flock_mode_openafs },
+ {"strict", afs_flock_mode_strict },
+ {"write", afs_flock_mode_write },
+ {}
+};
+
+static const struct fs_parameter_spec afs_fs_parameters[] = {
+ fsparam_flag ("autocell", Opt_autocell),
+ fsparam_flag ("dyn", Opt_dyn),
+ fsparam_enum ("flock", Opt_flock, afs_param_flock),
+ fsparam_string("source", Opt_source),
+ {}
+};
+
+/*
+ * initialise the filesystem
+ */
+int __init afs_fs_init(void)
+{
+ int ret;
+
+ _enter("");
+
+ /* create ourselves an inode cache */
+ atomic_set(&afs_count_active_inodes, 0);
+
+ ret = -ENOMEM;
+ afs_inode_cachep = kmem_cache_create("afs_inode_cache",
+ sizeof(struct afs_vnode),
+ 0,
+ SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
+ afs_i_init_once);
+ if (!afs_inode_cachep) {
+ printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n");
+ return ret;
+ }
+
+ /* now export our filesystem to lesser mortals */
+ ret = register_filesystem(&afs_fs_type);
+ if (ret < 0) {
+ kmem_cache_destroy(afs_inode_cachep);
+ _leave(" = %d", ret);
+ return ret;
+ }
+
+ _leave(" = 0");
+ return 0;
+}
+
+/*
+ * clean up the filesystem
+ */
+void afs_fs_exit(void)
+{
+ _enter("");
+
+ afs_mntpt_kill_timer();
+ unregister_filesystem(&afs_fs_type);
+
+ if (atomic_read(&afs_count_active_inodes) != 0) {
+ printk("kAFS: %d active inode objects still present\n",
+ atomic_read(&afs_count_active_inodes));
+ BUG();
+ }
+
+ /*
+ * Make sure all delayed rcu free inodes are flushed before we
+ * destroy cache.
+ */
+ rcu_barrier();
+ kmem_cache_destroy(afs_inode_cachep);
+ _leave("");
+}
+
+/*
+ * Display the mount device name in /proc/mounts.
+ */
+static int afs_show_devname(struct seq_file *m, struct dentry *root)
+{
+ struct afs_super_info *as = AFS_FS_S(root->d_sb);
+ struct afs_volume *volume = as->volume;
+ struct afs_cell *cell = as->cell;
+ const char *suf = "";
+ char pref = '%';
+
+ if (as->dyn_root) {
+ seq_puts(m, "none");
+ return 0;
+ }
+
+ switch (volume->type) {
+ case AFSVL_RWVOL:
+ break;
+ case AFSVL_ROVOL:
+ pref = '#';
+ if (volume->type_force)
+ suf = ".readonly";
+ break;
+ case AFSVL_BACKVOL:
+ pref = '#';
+ suf = ".backup";
+ break;
+ }
+
+ seq_printf(m, "%c%s:%s%s", pref, cell->name, volume->name, suf);
+ return 0;
+}
+
+/*
+ * Display the mount options in /proc/mounts.
+ */
+static int afs_show_options(struct seq_file *m, struct dentry *root)
+{
+ struct afs_super_info *as = AFS_FS_S(root->d_sb);
+ const char *p = NULL;
+
+ if (as->dyn_root)
+ seq_puts(m, ",dyn");
+ if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags))
+ seq_puts(m, ",autocell");
+ switch (as->flock_mode) {
+ case afs_flock_mode_unset: break;
+ case afs_flock_mode_local: p = "local"; break;
+ case afs_flock_mode_openafs: p = "openafs"; break;
+ case afs_flock_mode_strict: p = "strict"; break;
+ case afs_flock_mode_write: p = "write"; break;
+ }
+ if (p)
+ seq_printf(m, ",flock=%s", p);
+
+ return 0;
+}
+
+/*
+ * Parse the source name to get cell name, volume name, volume type and R/W
+ * selector.
+ *
+ * This can be one of the following:
+ * "%[cell:]volume[.]" R/W volume
+ * "#[cell:]volume[.]" R/O or R/W volume (R/O parent),
+ * or R/W (R/W parent) volume
+ * "%[cell:]volume.readonly" R/O volume
+ * "#[cell:]volume.readonly" R/O volume
+ * "%[cell:]volume.backup" Backup volume
+ * "#[cell:]volume.backup" Backup volume
+ */
+static int afs_parse_source(struct fs_context *fc, struct fs_parameter *param)
+{
+ struct afs_fs_context *ctx = fc->fs_private;
+ struct afs_cell *cell;
+ const char *cellname, *suffix, *name = param->string;
+ int cellnamesz;
+
+ _enter(",%s", name);
+
+ if (fc->source)
+ return invalf(fc, "kAFS: Multiple sources not supported");
+
+ if (!name) {
+ printk(KERN_ERR "kAFS: no volume name specified\n");
+ return -EINVAL;
+ }
+
+ if ((name[0] != '%' && name[0] != '#') || !name[1]) {
+ /* To use dynroot, we don't want to have to provide a source */
+ if (strcmp(name, "none") == 0) {
+ ctx->no_cell = true;
+ return 0;
+ }
+ printk(KERN_ERR "kAFS: unparsable volume name\n");
+ return -EINVAL;
+ }
+
+ /* determine the type of volume we're looking for */
+ if (name[0] == '%') {
+ ctx->type = AFSVL_RWVOL;
+ ctx->force = true;
+ }
+ name++;
+
+ /* split the cell name out if there is one */
+ ctx->volname = strchr(name, ':');
+ if (ctx->volname) {
+ cellname = name;
+ cellnamesz = ctx->volname - name;
+ ctx->volname++;
+ } else {
+ ctx->volname = name;
+ cellname = NULL;
+ cellnamesz = 0;
+ }
+
+ /* the volume type is further affected by a possible suffix */
+ suffix = strrchr(ctx->volname, '.');
+ if (suffix) {
+ if (strcmp(suffix, ".readonly") == 0) {
+ ctx->type = AFSVL_ROVOL;
+ ctx->force = true;
+ } else if (strcmp(suffix, ".backup") == 0) {
+ ctx->type = AFSVL_BACKVOL;
+ ctx->force = true;
+ } else if (suffix[1] == 0) {
+ } else {
+ suffix = NULL;
+ }
+ }
+
+ ctx->volnamesz = suffix ?
+ suffix - ctx->volname : strlen(ctx->volname);
+
+ _debug("cell %*.*s [%p]",
+ cellnamesz, cellnamesz, cellname ?: "", ctx->cell);
+
+ /* lookup the cell record */
+ if (cellname) {
+ cell = afs_lookup_cell(ctx->net, cellname, cellnamesz,
+ NULL, false);
+ if (IS_ERR(cell)) {
+ pr_err("kAFS: unable to lookup cell '%*.*s'\n",
+ cellnamesz, cellnamesz, cellname ?: "");
+ return PTR_ERR(cell);
+ }
+ afs_unuse_cell(ctx->net, ctx->cell, afs_cell_trace_unuse_parse);
+ afs_see_cell(cell, afs_cell_trace_see_source);
+ ctx->cell = cell;
+ }
+
+ _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
+ ctx->cell->name, ctx->cell,
+ ctx->volnamesz, ctx->volnamesz, ctx->volname,
+ suffix ?: "-", ctx->type, ctx->force ? " FORCE" : "");
+
+ fc->source = param->string;
+ param->string = NULL;
+ return 0;
+}
+
+/*
+ * Parse a single mount parameter.
+ */
+static int afs_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+ struct fs_parse_result result;
+ struct afs_fs_context *ctx = fc->fs_private;
+ int opt;
+
+ opt = fs_parse(fc, afs_fs_parameters, param, &result);
+ if (opt < 0)
+ return opt;
+
+ switch (opt) {
+ case Opt_source:
+ return afs_parse_source(fc, param);
+
+ case Opt_autocell:
+ ctx->autocell = true;
+ break;
+
+ case Opt_dyn:
+ ctx->dyn_root = true;
+ break;
+
+ case Opt_flock:
+ ctx->flock_mode = result.uint_32;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ _leave(" = 0");
+ return 0;
+}
+
+/*
+ * Validate the options, get the cell key and look up the volume.
+ */
+static int afs_validate_fc(struct fs_context *fc)
+{
+ struct afs_fs_context *ctx = fc->fs_private;
+ struct afs_volume *volume;
+ struct afs_cell *cell;
+ struct key *key;
+ int ret;
+
+ if (!ctx->dyn_root) {
+ if (ctx->no_cell) {
+ pr_warn("kAFS: Can only specify source 'none' with -o dyn\n");
+ return -EINVAL;
+ }
+
+ if (!ctx->cell) {
+ pr_warn("kAFS: No cell specified\n");
+ return -EDESTADDRREQ;
+ }
+
+ reget_key:
+ /* We try to do the mount securely. */
+ key = afs_request_key(ctx->cell);
+ if (IS_ERR(key))
+ return PTR_ERR(key);
+
+ ctx->key = key;
+
+ if (ctx->volume) {
+ afs_put_volume(ctx->net, ctx->volume,
+ afs_volume_trace_put_validate_fc);
+ ctx->volume = NULL;
+ }
+
+ if (test_bit(AFS_CELL_FL_CHECK_ALIAS, &ctx->cell->flags)) {
+ ret = afs_cell_detect_alias(ctx->cell, key);
+ if (ret < 0)
+ return ret;
+ if (ret == 1) {
+ _debug("switch to alias");
+ key_put(ctx->key);
+ ctx->key = NULL;
+ cell = afs_use_cell(ctx->cell->alias_of,
+ afs_cell_trace_use_fc_alias);
+ afs_unuse_cell(ctx->net, ctx->cell, afs_cell_trace_unuse_fc);
+ ctx->cell = cell;
+ goto reget_key;
+ }
+ }
+
+ volume = afs_create_volume(ctx);
+ if (IS_ERR(volume))
+ return PTR_ERR(volume);
+
+ ctx->volume = volume;
+ if (volume->type != AFSVL_RWVOL)
+ ctx->flock_mode = afs_flock_mode_local;
+ }
+
+ return 0;
+}
+
+/*
+ * check a superblock to see if it's the one we're looking for
+ */
+static int afs_test_super(struct super_block *sb, struct fs_context *fc)
+{
+ struct afs_fs_context *ctx = fc->fs_private;
+ struct afs_super_info *as = AFS_FS_S(sb);
+
+ return (as->net_ns == fc->net_ns &&
+ as->volume &&
+ as->volume->vid == ctx->volume->vid &&
+ as->cell == ctx->cell &&
+ !as->dyn_root);
+}
+
+static int afs_dynroot_test_super(struct super_block *sb, struct fs_context *fc)
+{
+ struct afs_super_info *as = AFS_FS_S(sb);
+
+ return (as->net_ns == fc->net_ns &&
+ as->dyn_root);
+}
+
+static int afs_set_super(struct super_block *sb, struct fs_context *fc)
+{
+ return set_anon_super(sb, NULL);
+}
+
+/*
+ * fill in the superblock
+ */
+static int afs_fill_super(struct super_block *sb, struct afs_fs_context *ctx)
+{
+ struct afs_super_info *as = AFS_FS_S(sb);
+ struct inode *inode = NULL;
+ int ret;
+
+ _enter("");
+
+ /* fill in the superblock */
+ sb->s_blocksize = PAGE_SIZE;
+ sb->s_blocksize_bits = PAGE_SHIFT;
+ sb->s_maxbytes = MAX_LFS_FILESIZE;
+ sb->s_magic = AFS_FS_MAGIC;
+ sb->s_op = &afs_super_ops;
+ if (!as->dyn_root)
+ sb->s_xattr = afs_xattr_handlers;
+ ret = super_setup_bdi(sb);
+ if (ret)
+ return ret;
+
+ /* allocate the root inode and dentry */
+ if (as->dyn_root) {
+ inode = afs_iget_pseudo_dir(sb, true);
+ } else {
+ sprintf(sb->s_id, "%llu", as->volume->vid);
+ afs_activate_volume(as->volume);
+ inode = afs_root_iget(sb, ctx->key);
+ }
+
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ if (ctx->autocell || as->dyn_root)
+ set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
+
+ ret = -ENOMEM;
+ sb->s_root = d_make_root(inode);
+ if (!sb->s_root)
+ goto error;
+
+ if (as->dyn_root) {
+ sb->s_d_op = &afs_dynroot_dentry_operations;
+ ret = afs_dynroot_populate(sb);
+ if (ret < 0)
+ goto error;
+ } else {
+ sb->s_d_op = &afs_fs_dentry_operations;
+ rcu_assign_pointer(as->volume->sb, sb);
+ }
+
+ _leave(" = 0");
+ return 0;
+
+error:
+ _leave(" = %d", ret);
+ return ret;
+}
+
+static struct afs_super_info *afs_alloc_sbi(struct fs_context *fc)
+{
+ struct afs_fs_context *ctx = fc->fs_private;
+ struct afs_super_info *as;
+
+ as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
+ if (as) {
+ as->net_ns = get_net(fc->net_ns);
+ as->flock_mode = ctx->flock_mode;
+ if (ctx->dyn_root) {
+ as->dyn_root = true;
+ } else {
+ as->cell = afs_use_cell(ctx->cell, afs_cell_trace_use_sbi);
+ as->volume = afs_get_volume(ctx->volume,
+ afs_volume_trace_get_alloc_sbi);
+ }
+ }
+ return as;
+}
+
+static void afs_destroy_sbi(struct afs_super_info *as)
+{
+ if (as) {
+ struct afs_net *net = afs_net(as->net_ns);
+ afs_put_volume(net, as->volume, afs_volume_trace_put_destroy_sbi);
+ afs_unuse_cell(net, as->cell, afs_cell_trace_unuse_sbi);
+ put_net(as->net_ns);
+ kfree(as);
+ }
+}
+
+static void afs_kill_super(struct super_block *sb)
+{
+ struct afs_super_info *as = AFS_FS_S(sb);
+
+ if (as->dyn_root)
+ afs_dynroot_depopulate(sb);
+
+ /* Clear the callback interests (which will do ilookup5) before
+ * deactivating the superblock.
+ */
+ if (as->volume)
+ rcu_assign_pointer(as->volume->sb, NULL);
+ kill_anon_super(sb);
+ if (as->volume)
+ afs_deactivate_volume(as->volume);
+ afs_destroy_sbi(as);
+}
+
+/*
+ * Get an AFS superblock and root directory.
+ */
+static int afs_get_tree(struct fs_context *fc)
+{
+ struct afs_fs_context *ctx = fc->fs_private;
+ struct super_block *sb;
+ struct afs_super_info *as;
+ int ret;
+
+ ret = afs_validate_fc(fc);
+ if (ret)
+ goto error;
+
+ _enter("");
+
+ /* allocate a superblock info record */
+ ret = -ENOMEM;
+ as = afs_alloc_sbi(fc);
+ if (!as)
+ goto error;
+ fc->s_fs_info = as;
+
+ /* allocate a deviceless superblock */
+ sb = sget_fc(fc,
+ as->dyn_root ? afs_dynroot_test_super : afs_test_super,
+ afs_set_super);
+ if (IS_ERR(sb)) {
+ ret = PTR_ERR(sb);
+ goto error;
+ }
+
+ if (!sb->s_root) {
+ /* initial superblock/root creation */
+ _debug("create");
+ ret = afs_fill_super(sb, ctx);
+ if (ret < 0)
+ goto error_sb;
+ sb->s_flags |= SB_ACTIVE;
+ } else {
+ _debug("reuse");
+ ASSERTCMP(sb->s_flags, &, SB_ACTIVE);
+ }
+
+ fc->root = dget(sb->s_root);
+ trace_afs_get_tree(as->cell, as->volume);
+ _leave(" = 0 [%p]", sb);
+ return 0;
+
+error_sb:
+ deactivate_locked_super(sb);
+error:
+ _leave(" = %d", ret);
+ return ret;
+}
+
+static void afs_free_fc(struct fs_context *fc)
+{
+ struct afs_fs_context *ctx = fc->fs_private;
+
+ afs_destroy_sbi(fc->s_fs_info);
+ afs_put_volume(ctx->net, ctx->volume, afs_volume_trace_put_free_fc);
+ afs_unuse_cell(ctx->net, ctx->cell, afs_cell_trace_unuse_fc);
+ key_put(ctx->key);
+ kfree(ctx);
+}
+
+static const struct fs_context_operations afs_context_ops = {
+ .free = afs_free_fc,
+ .parse_param = afs_parse_param,
+ .get_tree = afs_get_tree,
+};
+
+/*
+ * Set up the filesystem mount context.
+ */
+static int afs_init_fs_context(struct fs_context *fc)
+{
+ struct afs_fs_context *ctx;
+ struct afs_cell *cell;
+
+ ctx = kzalloc(sizeof(struct afs_fs_context), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->type = AFSVL_ROVOL;
+ ctx->net = afs_net(fc->net_ns);
+
+ /* Default to the workstation cell. */
+ cell = afs_find_cell(ctx->net, NULL, 0, afs_cell_trace_use_fc);
+ if (IS_ERR(cell))
+ cell = NULL;
+ ctx->cell = cell;
+
+ fc->fs_private = ctx;
+ fc->ops = &afs_context_ops;
+ return 0;
+}
+
+/*
+ * Initialise an inode cache slab element prior to any use. Note that
+ * afs_alloc_inode() *must* reset anything that could incorrectly leak from one
+ * inode to another.
+ */
+static void afs_i_init_once(void *_vnode)
+{
+ struct afs_vnode *vnode = _vnode;
+
+ memset(vnode, 0, sizeof(*vnode));
+ inode_init_once(&vnode->netfs.inode);
+ mutex_init(&vnode->io_lock);
+ init_rwsem(&vnode->validate_lock);
+ spin_lock_init(&vnode->wb_lock);
+ spin_lock_init(&vnode->lock);
+ INIT_LIST_HEAD(&vnode->wb_keys);
+ INIT_LIST_HEAD(&vnode->pending_locks);
+ INIT_LIST_HEAD(&vnode->granted_locks);
+ INIT_DELAYED_WORK(&vnode->lock_work, afs_lock_work);
+ INIT_LIST_HEAD(&vnode->cb_mmap_link);
+ seqlock_init(&vnode->cb_lock);
+}
+
+/*
+ * allocate an AFS inode struct from our slab cache
+ */
+static struct inode *afs_alloc_inode(struct super_block *sb)
+{
+ struct afs_vnode *vnode;
+
+ vnode = alloc_inode_sb(sb, afs_inode_cachep, GFP_KERNEL);
+ if (!vnode)
+ return NULL;
+
+ atomic_inc(&afs_count_active_inodes);
+
+ /* Reset anything that shouldn't leak from one inode to the next. */
+ memset(&vnode->fid, 0, sizeof(vnode->fid));
+ memset(&vnode->status, 0, sizeof(vnode->status));
+ afs_vnode_set_cache(vnode, NULL);
+
+ vnode->volume = NULL;
+ vnode->lock_key = NULL;
+ vnode->permit_cache = NULL;
+
+ vnode->flags = 1 << AFS_VNODE_UNSET;
+ vnode->lock_state = AFS_VNODE_LOCK_NONE;
+
+ init_rwsem(&vnode->rmdir_lock);
+ INIT_WORK(&vnode->cb_work, afs_invalidate_mmap_work);
+
+ _leave(" = %p", &vnode->netfs.inode);
+ return &vnode->netfs.inode;
+}
+
+static void afs_free_inode(struct inode *inode)
+{
+ kmem_cache_free(afs_inode_cachep, AFS_FS_I(inode));
+}
+
+/*
+ * destroy an AFS inode struct
+ */
+static void afs_destroy_inode(struct inode *inode)
+{
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+
+ _enter("%p{%llx:%llu}", inode, vnode->fid.vid, vnode->fid.vnode);
+
+ _debug("DESTROY INODE %p", inode);
+
+ atomic_dec(&afs_count_active_inodes);
+}
+
+static void afs_get_volume_status_success(struct afs_operation *op)
+{
+ struct afs_volume_status *vs = &op->volstatus.vs;
+ struct kstatfs *buf = op->volstatus.buf;
+
+ if (vs->max_quota == 0)
+ buf->f_blocks = vs->part_max_blocks;
+ else
+ buf->f_blocks = vs->max_quota;
+
+ if (buf->f_blocks > vs->blocks_in_use)
+ buf->f_bavail = buf->f_bfree =
+ buf->f_blocks - vs->blocks_in_use;
+}
+
+static const struct afs_operation_ops afs_get_volume_status_operation = {
+ .issue_afs_rpc = afs_fs_get_volume_status,
+ .issue_yfs_rpc = yfs_fs_get_volume_status,
+ .success = afs_get_volume_status_success,
+};
+
+/*
+ * return information about an AFS volume
+ */
+static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ struct afs_super_info *as = AFS_FS_S(dentry->d_sb);
+ struct afs_operation *op;
+ struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
+
+ buf->f_type = dentry->d_sb->s_magic;
+ buf->f_bsize = AFS_BLOCK_SIZE;
+ buf->f_namelen = AFSNAMEMAX - 1;
+
+ if (as->dyn_root) {
+ buf->f_blocks = 1;
+ buf->f_bavail = 0;
+ buf->f_bfree = 0;
+ return 0;
+ }
+
+ op = afs_alloc_operation(NULL, as->volume);
+ if (IS_ERR(op))
+ return PTR_ERR(op);
+
+ afs_op_set_vnode(op, 0, vnode);
+ op->nr_files = 1;
+ op->volstatus.buf = buf;
+ op->ops = &afs_get_volume_status_operation;
+ return afs_do_sync_operation(op);
+}