- Overview.
- Usage.
- Mountpoints.
+ - Dynamic root.
- Proc filesystem.
- The cell database.
- Security.
umount /afs
+============
+DYNAMIC ROOT
+============
+
+A mount option is available to create a serverless mount that is only usable
+for dynamic lookup. Creating such a mount can be done by, for example:
+
+ mount -t afs none /afs -o dyn
+
+This creates a mount that just has an empty directory at the root. Attempting
+to look up a name in this directory will cause a mountpoint to be created that
+looks up a cell of the same name, for example:
+
+ ls /afs/grand.central.org/
+
+
===============
PROC FILESYSTEM
===============
#include <linux/pagemap.h>
#include <linux/ctype.h>
#include <linux/sched.h>
+#include <linux/dns_resolver.h>
#include "internal.h"
static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags);
+static struct dentry *afs_dynroot_lookup(struct inode *dir, struct dentry *dentry,
+ unsigned int flags);
static int afs_dir_open(struct inode *inode, struct file *file);
static int afs_readdir(struct file *file, struct dir_context *ctx);
static int afs_d_revalidate(struct dentry *dentry, unsigned int flags);
.listxattr = afs_listxattr,
};
+const struct file_operations afs_dynroot_file_operations = {
+ .open = dcache_dir_open,
+ .release = dcache_dir_close,
+ .iterate_shared = dcache_readdir,
+ .llseek = dcache_dir_lseek,
+};
+
+const struct inode_operations afs_dynroot_inode_operations = {
+ .lookup = afs_dynroot_lookup,
+};
+
const struct dentry_operations afs_fs_dentry_operations = {
.d_revalidate = afs_d_revalidate,
.d_delete = afs_d_delete,
return 0;
}
+/*
+ * Probe to see if a cell may exist. This prevents positive dentries from
+ * being created unnecessarily.
+ */
+static int afs_probe_cell_name(struct dentry *dentry)
+{
+ struct afs_cell *cell;
+ const char *name = dentry->d_name.name;
+ size_t len = dentry->d_name.len;
+ int ret;
+
+ /* Names prefixed with a dot are R/W mounts. */
+ if (name[0] == '.') {
+ if (len == 1)
+ return -EINVAL;
+ name++;
+ len--;
+ }
+
+ cell = afs_lookup_cell_rcu(afs_d2net(dentry), name, len);
+ if (!IS_ERR(cell)) {
+ afs_put_cell(afs_d2net(dentry), cell);
+ return 0;
+ }
+
+ ret = dns_query("afsdb", name, len, "ipv4", NULL, NULL);
+ if (ret == -ENODATA)
+ ret = -EDESTADDRREQ;
+ return ret;
+}
+
/*
* Try to auto mount the mountpoint with pseudo directory, if the autocell
* operation is setted.
*/
-static struct inode *afs_try_auto_mntpt(
- int ret, struct dentry *dentry, struct inode *dir, struct key *key,
- struct afs_fid *fid)
+static struct inode *afs_try_auto_mntpt(struct dentry *dentry,
+ struct inode *dir, struct afs_fid *fid)
{
- const char *devname = dentry->d_name.name;
struct afs_vnode *vnode = AFS_FS_I(dir);
struct inode *inode;
+ int ret = -ENOENT;
- _enter("%d, %p{%pd}, {%x:%u}, %p",
- ret, dentry, dentry, vnode->fid.vid, vnode->fid.vnode, key);
+ _enter("%p{%pd}, {%x:%u}",
+ dentry, dentry, vnode->fid.vid, vnode->fid.vnode);
+
+ if (!test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
+ goto out;
- if (ret != -ENOENT ||
- !test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
+ ret = afs_probe_cell_name(dentry);
+ if (ret < 0)
goto out;
- inode = afs_iget_autocell(dir, devname, strlen(devname), key);
+ inode = afs_iget_pseudo_dir(dir->i_sb, false);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
goto out;
ret = afs_do_lookup(dir, dentry, &fid, key);
if (ret < 0) {
- inode = afs_try_auto_mntpt(ret, dentry, dir, key, &fid);
- if (!IS_ERR(inode)) {
- key_put(key);
- goto success;
+ if (ret == -ENOENT) {
+ inode = afs_try_auto_mntpt(dentry, dir, &fid);
+ if (!IS_ERR(inode)) {
+ key_put(key);
+ goto success;
+ }
+
+ ret = PTR_ERR(inode);
}
- ret = PTR_ERR(inode);
key_put(key);
if (ret == -ENOENT) {
d_add(dentry, NULL);
return NULL;
}
+/*
+ * Look up an entry in a dynroot directory.
+ */
+static struct dentry *afs_dynroot_lookup(struct inode *dir, struct dentry *dentry,
+ unsigned int flags)
+{
+ struct afs_vnode *vnode;
+ struct afs_fid fid;
+ struct inode *inode;
+ int ret;
+
+ vnode = AFS_FS_I(dir);
+
+ _enter("%pd", dentry);
+
+ ASSERTCMP(d_inode(dentry), ==, NULL);
+
+ if (dentry->d_name.len >= AFSNAMEMAX) {
+ _leave(" = -ENAMETOOLONG");
+ return ERR_PTR(-ENAMETOOLONG);
+ }
+
+ inode = afs_try_auto_mntpt(dentry, dir, &fid);
+ if (IS_ERR(inode)) {
+ ret = PTR_ERR(inode);
+ if (ret == -ENOENT) {
+ d_add(dentry, NULL);
+ _leave(" = NULL [negative]");
+ return NULL;
+ }
+ _leave(" = %d [do]", ret);
+ return ERR_PTR(ret);
+ }
+
+ d_add(dentry, inode);
+ _leave(" = 0 { ino=%lu v=%u }",
+ d_inode(dentry)->i_ino, d_inode(dentry)->i_generation);
+ return NULL;
+}
+
/*
* check that a dentry lookup hit has found a valid entry
* - NOTE! the hit can be a negative hit too, so we can't assume we have an
*/
static int afs_d_revalidate(struct dentry *dentry, unsigned int flags)
{
+ struct afs_super_info *as = dentry->d_sb->s_fs_info;
struct afs_vnode *vnode, *dir;
struct afs_fid uninitialized_var(fid);
struct dentry *parent;
if (flags & LOOKUP_RCU)
return -ECHILD;
+ if (as->dyn_root)
+ return 1;
+
if (d_really_is_positive(dentry)) {
vnode = AFS_FS_I(d_inode(dentry));
_enter("{v={%x:%u} n=%pd fl=%lx},",
*
* These pseudo inodes don't match anything.
*/
-static int afs_iget5_autocell_test(struct inode *inode, void *opaque)
+static int afs_iget5_pseudo_dir_test(struct inode *inode, void *opaque)
{
return 0;
}
}
/*
- * inode retrieval for autocell
+ * Create an inode for a dynamic root directory or an autocell dynamic
+ * automount dir.
*/
-struct inode *afs_iget_autocell(struct inode *dir, const char *dev_name,
- int namesz, struct key *key)
+struct inode *afs_iget_pseudo_dir(struct super_block *sb, bool root)
{
struct afs_iget_data data;
struct afs_super_info *as;
struct afs_vnode *vnode;
- struct super_block *sb;
struct inode *inode;
static atomic_t afs_autocell_ino;
- _enter("{%x:%u},%*.*s,",
- AFS_FS_I(dir)->fid.vid, AFS_FS_I(dir)->fid.vnode,
- namesz, namesz, dev_name ?: "");
+ _enter("");
- sb = dir->i_sb;
as = sb->s_fs_info;
- data.volume = as->volume;
- data.fid.vid = as->volume->vid;
- data.fid.unique = 0;
- data.fid.vnode = 0;
+ if (as->volume) {
+ data.volume = as->volume;
+ data.fid.vid = as->volume->vid;
+ }
+ if (root) {
+ data.fid.vnode = 1;
+ data.fid.unique = 1;
+ } else {
+ data.fid.vnode = atomic_inc_return(&afs_autocell_ino);
+ data.fid.unique = 0;
+ }
- inode = iget5_locked(sb, atomic_inc_return(&afs_autocell_ino),
- afs_iget5_autocell_test, afs_iget5_set,
+ inode = iget5_locked(sb, data.fid.vnode,
+ afs_iget5_pseudo_dir_test, afs_iget5_set,
&data);
if (!inode) {
_leave(" = -ENOMEM");
inode->i_size = 0;
inode->i_mode = S_IFDIR | S_IRUGO | S_IXUGO;
- inode->i_op = &afs_autocell_inode_operations;
+ if (root) {
+ inode->i_op = &afs_dynroot_inode_operations;
+ inode->i_fop = &afs_dynroot_file_operations;
+ } else {
+ inode->i_op = &afs_autocell_inode_operations;
+ }
set_nlink(inode, 2);
inode->i_uid = GLOBAL_ROOT_UID;
inode->i_gid = GLOBAL_ROOT_GID;
inode->i_generation = 0;
set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags);
- set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
- inode->i_flags |= S_AUTOMOUNT | S_NOATIME;
+ if (!root) {
+ set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
+ inode->i_flags |= S_AUTOMOUNT;
+ }
+
+ inode->i_flags |= S_NOATIME;
unlock_new_inode(inode);
_leave(" = %p", inode);
return inode;
bool rwpath; /* T if the parent should be considered R/W */
bool force; /* T to force cell type */
bool autocell; /* T if set auto mount operation */
+ bool dyn_root; /* T if dynamic root */
afs_voltype_t type; /* type of volume requested */
int volnamesz; /* size of volume name */
const char *volname; /* name of volume to mount */
struct afs_net *net; /* Network namespace */
struct afs_cell *cell; /* The cell in which the volume resides */
struct afs_volume *volume; /* volume record */
+ bool dyn_root; /* True if dynamic root */
};
static inline struct afs_super_info *AFS_FS_S(struct super_block *sb)
/*
* dir.c
*/
-extern bool afs_dir_check_page(struct inode *, struct page *);
+extern const struct file_operations afs_dir_file_operations;
extern const struct inode_operations afs_dir_inode_operations;
+extern const struct file_operations afs_dynroot_file_operations;
+extern const struct inode_operations afs_dynroot_inode_operations;
extern const struct dentry_operations afs_fs_dentry_operations;
-extern const struct file_operations afs_dir_file_operations;
+
+extern bool afs_dir_check_page(struct inode *, struct page *);
/*
* file.c
*/
extern int afs_fetch_status(struct afs_vnode *, struct key *);
extern int afs_iget5_test(struct inode *, void *);
-extern struct inode *afs_iget_autocell(struct inode *, const char *, int,
- struct key *);
+extern struct inode *afs_iget_pseudo_dir(struct super_block *, bool);
extern struct inode *afs_iget(struct super_block *, struct key *,
struct afs_fid *, struct afs_file_status *,
struct afs_callback *,
*/
static struct vfsmount *afs_mntpt_do_automount(struct dentry *mntpt)
{
- struct afs_super_info *super;
+ struct afs_super_info *as;
struct vfsmount *mnt;
struct afs_vnode *vnode;
struct page *page;
goto error_no_page;
if (mntpt->d_name.name[0] == '.') {
- devname[0] = '#';
- memcpy(devname + 1, mntpt->d_name.name, size - 1);
+ devname[0] = '%';
+ memcpy(devname + 1, mntpt->d_name.name + 1, size - 1);
memcpy(devname + size, afs_root_cell,
sizeof(afs_root_cell));
rwpath = true;
} else {
- devname[0] = '%';
+ devname[0] = '#';
memcpy(devname + 1, mntpt->d_name.name, size);
memcpy(devname + size + 1, afs_root_cell,
sizeof(afs_root_cell));
}
/* work out what options we want */
- super = AFS_FS_S(mntpt->d_sb);
- memcpy(options, "cell=", 5);
- strcpy(options + 5, super->volume->cell->name);
- if (super->volume->type == AFSVL_RWVOL || rwpath)
- strcat(options, ",rwpath");
+ as = AFS_FS_S(mntpt->d_sb);
+ if (as->cell) {
+ memcpy(options, "cell=", 5);
+ strcpy(options + 5, as->cell->name);
+ if ((as->volume && as->volume->type == AFSVL_RWVOL) || rwpath)
+ strcat(options, ",rwpath");
+ }
/* try and do the mount */
_debug("--- attempting mount %s -o %s ---", devname, options);
enum {
afs_no_opt,
afs_opt_cell,
+ afs_opt_dyn,
afs_opt_rwpath,
afs_opt_vol,
afs_opt_autocell,
static const match_table_t afs_options_list = {
{ afs_opt_cell, "cell=%s" },
+ { afs_opt_dyn, "dyn" },
{ afs_opt_rwpath, "rwpath" },
{ afs_opt_vol, "vol=%s" },
{ afs_opt_autocell, "autocell" },
const char *suf = "";
char pref = '%';
+ if (as->dyn_root) {
+ seq_puts(m, "none");
+ return 0;
+ }
+
switch (volume->type) {
case AFSVL_RWVOL:
break;
*/
static int afs_show_options(struct seq_file *m, struct dentry *root)
{
+ struct afs_super_info *as = AFS_FS_S(root->d_sb);
+
+ 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");
+ seq_puts(m, ",autocell");
return 0;
}
break;
case afs_opt_rwpath:
- params->rwpath = 1;
+ params->rwpath = true;
break;
case afs_opt_vol:
break;
case afs_opt_autocell:
- params->autocell = 1;
+ params->autocell = true;
+ break;
+
+ case afs_opt_dyn:
+ params->dyn_root = true;
break;
default:
int cellnamesz;
_enter(",%s", name);
-
+
if (!name) {
printk(KERN_ERR "kAFS: no volume name specified\n");
return -EINVAL;
struct afs_super_info *as1 = data;
struct afs_super_info *as = AFS_FS_S(sb);
- return as->net == as1->net && as->volume->vid == as1->volume->vid;
+ return (as->net == as1->net &&
+ as->volume &&
+ as->volume->vid == as1->volume->vid);
+}
+
+static int afs_dynroot_test_super(struct super_block *sb, void *data)
+{
+ return false;
}
static int afs_set_super(struct super_block *sb, void *data)
sb->s_blocksize_bits = PAGE_SHIFT;
sb->s_magic = AFS_FS_MAGIC;
sb->s_op = &afs_super_ops;
- sb->s_xattr = afs_xattr_handlers;
+ if (!as->dyn_root)
+ sb->s_xattr = afs_xattr_handlers;
ret = super_setup_bdi(sb);
if (ret)
return ret;
sb->s_bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_SIZE;
- sprintf(sb->s_id, "%u", as->volume->vid);
-
- afs_activate_volume(as->volume);
/* allocate the root inode and dentry */
- fid.vid = as->volume->vid;
- fid.vnode = 1;
- fid.unique = 1;
- inode = afs_iget(sb, params->key, &fid, NULL, NULL, NULL);
+ if (as->dyn_root) {
+ inode = afs_iget_pseudo_dir(sb, true);
+ sb->s_flags |= SB_RDONLY;
+ } else {
+ sprintf(sb->s_id, "%u", as->volume->vid);
+ afs_activate_volume(as->volume);
+ fid.vid = as->volume->vid;
+ fid.vnode = 1;
+ fid.unique = 1;
+ inode = afs_iget(sb, params->key, &fid, NULL, NULL, NULL);
+ }
+
if (IS_ERR(inode))
return PTR_ERR(inode);
- if (params->autocell)
+ if (params->autocell || params->dyn_root)
set_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(inode)->flags);
ret = -ENOMEM;
as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
if (as) {
as->net = afs_get_net(params->net);
- as->cell = afs_get_cell(params->cell);
+ if (params->dyn_root)
+ as->dyn_root = true;
+ else
+ as->cell = afs_get_cell(params->cell);
}
return as;
}
goto error;
}
- ret = afs_parse_device_name(¶ms, dev_name);
- if (ret < 0)
- goto error;
+ if (!params.dyn_root) {
+ ret = afs_parse_device_name(¶ms, dev_name);
+ if (ret < 0)
+ goto error;
- /* try and do the mount securely */
- key = afs_request_key(params.cell);
- if (IS_ERR(key)) {
- _leave(" = %ld [key]", PTR_ERR(key));
- ret = PTR_ERR(key);
- goto error;
+ /* try and do the mount securely */
+ key = afs_request_key(params.cell);
+ if (IS_ERR(key)) {
+ _leave(" = %ld [key]", PTR_ERR(key));
+ ret = PTR_ERR(key);
+ goto error;
+ }
+ params.key = key;
}
- params.key = key;
/* allocate a superblock info record */
ret = -ENOMEM;
if (!as)
goto error_key;
- /* Assume we're going to need a volume record; at the very least we can
- * use it to update the volume record if we have one already. This
- * checks that the volume exists within the cell.
- */
- candidate = afs_create_volume(¶ms);
- if (IS_ERR(candidate)) {
- ret = PTR_ERR(candidate);
- goto error_as;
- }
+ if (!params.dyn_root) {
+ /* Assume we're going to need a volume record; at the very
+ * least we can use it to update the volume record if we have
+ * one already. This checks that the volume exists within the
+ * cell.
+ */
+ candidate = afs_create_volume(¶ms);
+ if (IS_ERR(candidate)) {
+ ret = PTR_ERR(candidate);
+ goto error_as;
+ }
- as->volume = candidate;
+ as->volume = candidate;
+ }
/* allocate a deviceless superblock */
- sb = sget(fs_type, afs_test_super, afs_set_super, flags, as);
+ sb = sget(fs_type,
+ as->dyn_root ? afs_dynroot_test_super : afs_test_super,
+ afs_set_super, flags, as);
if (IS_ERR(sb)) {
ret = PTR_ERR(sb);
goto error_as;
/* Clear the callback interests (which will do ilookup5) before
* deactivating the superblock.
*/
- afs_clear_callback_interests(as->net, as->volume->servers);
+ if (as->volume)
+ afs_clear_callback_interests(as->net, as->volume->servers);
kill_anon_super(sb);
- afs_deactivate_volume(as->volume);
+ if (as->volume)
+ afs_deactivate_volume(as->volume);
afs_destroy_sbi(as);
}
*/
static int afs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
+ struct afs_super_info *as = AFS_FS_S(dentry->d_sb);
struct afs_fs_cursor fc;
struct afs_volume_status vs;
struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
struct key *key;
int ret;
+ 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;
+ }
+
key = afs_request_key(vnode->volume->cell);
if (IS_ERR(key))
return PTR_ERR(key);
key_put(key);
if (ret == 0) {
- buf->f_type = dentry->d_sb->s_magic;
- buf->f_bsize = AFS_BLOCK_SIZE;
- buf->f_namelen = AFSNAMEMAX - 1;
-
if (vs.max_quota == 0)
buf->f_blocks = vs.part_max_blocks;
else
* @name: Name to look up
* @namelen: Length of name
* @options: Request options (or NULL if no options)
- * @_result: Where to place the returned data.
+ * @_result: Where to place the returned data (or NULL)
* @_expiry: Where to store the result expiry time (or NULL)
*
- * The data will be returned in the pointer at *result, and the caller is
- * responsible for freeing it.
+ * The data will be returned in the pointer at *result, if provided, and the
+ * caller is responsible for freeing it.
*
* The description should be of the form "[<query_type>:]<domain_name>", and
* the options need to be appropriate for the query type requested. If no
kenter("%s,%*.*s,%zu,%s",
type, (int)namelen, (int)namelen, name, namelen, options);
- if (!name || namelen == 0 || !_result)
+ if (!name || namelen == 0)
return -EINVAL;
/* construct the query key description as "[<type>:]<name>" */
upayload = user_key_payload_locked(rkey);
len = upayload->datalen;
- ret = -ENOMEM;
- *_result = kmalloc(len + 1, GFP_KERNEL);
- if (!*_result)
- goto put;
+ if (_result) {
+ ret = -ENOMEM;
+ *_result = kmalloc(len + 1, GFP_KERNEL);
+ if (!*_result)
+ goto put;
- memcpy(*_result, upayload->data, len);
- (*_result)[len] = '\0';
+ memcpy(*_result, upayload->data, len);
+ (*_result)[len] = '\0';
+ }
if (_expiry)
*_expiry = rkey->expiry;
projects / linux-2.6-microblaze.git / commitdiff