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-rw-r--r--fs/afs/super.c728
1 files changed, 728 insertions, 0 deletions
diff --git a/fs/afs/super.c b/fs/afs/super.c
new file mode 100644
index 000000000..4961d32cc
--- /dev/null
+++ b/fs/afs/super.c
@@ -0,0 +1,728 @@
+/* AFS superblock handling
+ *
+ * Copyright (c) 2002, 2007 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/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 struct dentry *afs_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *data);
+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_show_devname(struct seq_file *m, struct dentry *root);
+static int afs_show_options(struct seq_file *m, struct dentry *root);
+
+struct file_system_type afs_fs_type = {
+ .owner = THIS_MODULE,
+ .name = "afs",
+ .mount = afs_mount,
+ .kill_sb = afs_kill_super,
+ .fs_flags = 0,
+};
+MODULE_ALIAS_FS("afs");
+
+int afs_net_id;
+
+static const struct super_operations afs_super_ops = {
+ .statfs = afs_statfs,
+ .alloc_inode = afs_alloc_inode,
+ .drop_inode = afs_drop_inode,
+ .destroy_inode = afs_destroy_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_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" },
+ { afs_no_opt, NULL },
+};
+
+/*
+ * 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);
+
+ 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");
+ return 0;
+}
+
+/*
+ * parse the mount options
+ * - this function has been shamelessly adapted from the ext3 fs which
+ * shamelessly adapted it from the msdos fs
+ */
+static int afs_parse_options(struct afs_mount_params *params,
+ char *options, const char **devname)
+{
+ struct afs_cell *cell;
+ substring_t args[MAX_OPT_ARGS];
+ char *p;
+ int token;
+
+ _enter("%s", options);
+
+ options[PAGE_SIZE - 1] = 0;
+
+ while ((p = strsep(&options, ","))) {
+ if (!*p)
+ continue;
+
+ token = match_token(p, afs_options_list, args);
+ switch (token) {
+ case afs_opt_cell:
+ rcu_read_lock();
+ cell = afs_lookup_cell_rcu(params->net,
+ args[0].from,
+ args[0].to - args[0].from);
+ rcu_read_unlock();
+ if (IS_ERR(cell))
+ return PTR_ERR(cell);
+ afs_put_cell(params->net, params->cell);
+ params->cell = cell;
+ break;
+
+ case afs_opt_rwpath:
+ params->rwpath = true;
+ break;
+
+ case afs_opt_vol:
+ *devname = args[0].from;
+ break;
+
+ case afs_opt_autocell:
+ params->autocell = true;
+ break;
+
+ case afs_opt_dyn:
+ params->dyn_root = true;
+ break;
+
+ default:
+ printk(KERN_ERR "kAFS:"
+ " Unknown or invalid mount option: '%s'\n", p);
+ return -EINVAL;
+ }
+ }
+
+ _leave(" = 0");
+ return 0;
+}
+
+/*
+ * parse a device 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 (rwpath=0),
+ * or R/W (rwpath=1) 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_device_name(struct afs_mount_params *params,
+ const char *name)
+{
+ struct afs_cell *cell;
+ const char *cellname, *suffix;
+ int cellnamesz;
+
+ _enter(",%s", name);
+
+ if (!name) {
+ printk(KERN_ERR "kAFS: no volume name specified\n");
+ return -EINVAL;
+ }
+
+ if ((name[0] != '%' && name[0] != '#') || !name[1]) {
+ printk(KERN_ERR "kAFS: unparsable volume name\n");
+ return -EINVAL;
+ }
+
+ /* determine the type of volume we're looking for */
+ params->type = AFSVL_ROVOL;
+ params->force = false;
+ if (params->rwpath || name[0] == '%') {
+ params->type = AFSVL_RWVOL;
+ params->force = true;
+ }
+ name++;
+
+ /* split the cell name out if there is one */
+ params->volname = strchr(name, ':');
+ if (params->volname) {
+ cellname = name;
+ cellnamesz = params->volname - name;
+ params->volname++;
+ } else {
+ params->volname = name;
+ cellname = NULL;
+ cellnamesz = 0;
+ }
+
+ /* the volume type is further affected by a possible suffix */
+ suffix = strrchr(params->volname, '.');
+ if (suffix) {
+ if (strcmp(suffix, ".readonly") == 0) {
+ params->type = AFSVL_ROVOL;
+ params->force = true;
+ } else if (strcmp(suffix, ".backup") == 0) {
+ params->type = AFSVL_BACKVOL;
+ params->force = true;
+ } else if (suffix[1] == 0) {
+ } else {
+ suffix = NULL;
+ }
+ }
+
+ params->volnamesz = suffix ?
+ suffix - params->volname : strlen(params->volname);
+
+ _debug("cell %*.*s [%p]",
+ cellnamesz, cellnamesz, cellname ?: "", params->cell);
+
+ /* lookup the cell record */
+ if (cellname || !params->cell) {
+ cell = afs_lookup_cell(params->net, cellname, cellnamesz,
+ NULL, false);
+ if (IS_ERR(cell)) {
+ printk(KERN_ERR "kAFS: unable to lookup cell '%*.*s'\n",
+ cellnamesz, cellnamesz, cellname ?: "");
+ return PTR_ERR(cell);
+ }
+ afs_put_cell(params->net, params->cell);
+ params->cell = cell;
+ }
+
+ _debug("CELL:%s [%p] VOLUME:%*.*s SUFFIX:%s TYPE:%d%s",
+ params->cell->name, params->cell,
+ params->volnamesz, params->volnamesz, params->volname,
+ suffix ?: "-", params->type, params->force ? " FORCE" : "");
+
+ 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, void *data)
+{
+ struct afs_super_info *as1 = data;
+ struct afs_super_info *as = AFS_FS_S(sb);
+
+ return (as->net_ns == as1->net_ns &&
+ as->volume &&
+ as->volume->vid == as1->volume->vid &&
+ as->cell == as1->cell &&
+ !as->dyn_root);
+}
+
+static int afs_dynroot_test_super(struct super_block *sb, void *data)
+{
+ struct afs_super_info *as1 = data;
+ struct afs_super_info *as = AFS_FS_S(sb);
+
+ return (as->net_ns == as1->net_ns &&
+ as->dyn_root);
+}
+
+static int afs_set_super(struct super_block *sb, void *data)
+{
+ struct afs_super_info *as = data;
+
+ sb->s_fs_info = as;
+ return set_anon_super(sb, NULL);
+}
+
+/*
+ * fill in the superblock
+ */
+static int afs_fill_super(struct super_block *sb,
+ struct afs_mount_params *params)
+{
+ struct afs_super_info *as = AFS_FS_S(sb);
+ struct afs_fid fid;
+ 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;
+ sb->s_bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_SIZE;
+
+ /* allocate the root inode and dentry */
+ if (as->dyn_root) {
+ inode = afs_iget_pseudo_dir(sb, true);
+ } 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 || params->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;
+ }
+
+ _leave(" = 0");
+ return 0;
+
+error:
+ _leave(" = %d", ret);
+ return ret;
+}
+
+static struct afs_super_info *afs_alloc_sbi(struct afs_mount_params *params)
+{
+ struct afs_super_info *as;
+
+ as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
+ if (as) {
+ as->net_ns = get_net(params->net_ns);
+ if (params->dyn_root)
+ as->dyn_root = true;
+ else
+ as->cell = afs_get_cell(params->cell);
+ }
+ return as;
+}
+
+static void afs_destroy_sbi(struct afs_super_info *as)
+{
+ if (as) {
+ afs_put_volume(as->cell, as->volume);
+ afs_put_cell(afs_net(as->net_ns), as->cell);
+ 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);
+ struct afs_net *net = afs_net(as->net_ns);
+
+ if (as->dyn_root)
+ afs_dynroot_depopulate(sb);
+
+ /* Clear the callback interests (which will do ilookup5) before
+ * deactivating the superblock.
+ */
+ if (as->volume)
+ afs_clear_callback_interests(net, as->volume->servers);
+ kill_anon_super(sb);
+ if (as->volume)
+ afs_deactivate_volume(as->volume);
+ afs_destroy_sbi(as);
+}
+
+/*
+ * get an AFS superblock
+ */
+static struct dentry *afs_mount(struct file_system_type *fs_type,
+ int flags, const char *dev_name, void *options)
+{
+ struct afs_mount_params params;
+ struct super_block *sb;
+ struct afs_volume *candidate;
+ struct key *key;
+ struct afs_super_info *as;
+ int ret;
+
+ _enter(",,%s,%p", dev_name, options);
+
+ memset(&params, 0, sizeof(params));
+
+ ret = -EINVAL;
+ if (current->nsproxy->net_ns != &init_net)
+ goto error;
+ params.net_ns = current->nsproxy->net_ns;
+ params.net = afs_net(params.net_ns);
+
+ /* parse the options and device name */
+ if (options) {
+ ret = afs_parse_options(&params, options, &dev_name);
+ if (ret < 0)
+ goto error;
+ }
+
+ if (!params.dyn_root) {
+ ret = afs_parse_device_name(&params, 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;
+ }
+ params.key = key;
+ }
+
+ /* allocate a superblock info record */
+ ret = -ENOMEM;
+ as = afs_alloc_sbi(&params);
+ if (!as)
+ goto error_key;
+
+ 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(&params);
+ if (IS_ERR(candidate)) {
+ ret = PTR_ERR(candidate);
+ goto error_as;
+ }
+
+ as->volume = candidate;
+ }
+
+ /* allocate a deviceless superblock */
+ 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;
+ }
+
+ if (!sb->s_root) {
+ /* initial superblock/root creation */
+ _debug("create");
+ ret = afs_fill_super(sb, &params);
+ if (ret < 0)
+ goto error_sb;
+ as = NULL;
+ sb->s_flags |= SB_ACTIVE;
+ } else {
+ _debug("reuse");
+ ASSERTCMP(sb->s_flags, &, SB_ACTIVE);
+ afs_destroy_sbi(as);
+ as = NULL;
+ }
+
+ afs_put_cell(params.net, params.cell);
+ key_put(params.key);
+ _leave(" = 0 [%p]", sb);
+ return dget(sb->s_root);
+
+error_sb:
+ deactivate_locked_super(sb);
+ goto error_key;
+error_as:
+ afs_destroy_sbi(as);
+error_key:
+ key_put(params.key);
+error:
+ afs_put_cell(params.net, params.cell);
+ _leave(" = %d", ret);
+ return ERR_PTR(ret);
+}
+
+/*
+ * 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->vfs_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);
+ 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 = kmem_cache_alloc(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));
+
+ vnode->volume = NULL;
+ vnode->lock_key = NULL;
+ vnode->permit_cache = NULL;
+ vnode->cb_interest = NULL;
+#ifdef CONFIG_AFS_FSCACHE
+ vnode->cache = NULL;
+#endif
+
+ vnode->flags = 1 << AFS_VNODE_UNSET;
+ vnode->cb_type = 0;
+ vnode->lock_state = AFS_VNODE_LOCK_NONE;
+
+ _leave(" = %p", &vnode->vfs_inode);
+ return &vnode->vfs_inode;
+}
+
+static void afs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+ kmem_cache_free(afs_inode_cachep, vnode);
+}
+
+/*
+ * destroy an AFS inode struct
+ */
+static void afs_destroy_inode(struct inode *inode)
+{
+ struct afs_vnode *vnode = AFS_FS_I(inode);
+
+ _enter("%p{%x:%u}", inode, vnode->fid.vid, vnode->fid.vnode);
+
+ _debug("DESTROY INODE %p", inode);
+
+ ASSERTCMP(vnode->cb_interest, ==, NULL);
+
+ call_rcu(&inode->i_rcu, afs_i_callback);
+ atomic_dec(&afs_count_active_inodes);
+}
+
+/*
+ * 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_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);
+
+ ret = -ERESTARTSYS;
+ if (afs_begin_vnode_operation(&fc, vnode, key)) {
+ fc.flags |= AFS_FS_CURSOR_NO_VSLEEP;
+ while (afs_select_fileserver(&fc)) {
+ fc.cb_break = afs_calc_vnode_cb_break(vnode);
+ afs_fs_get_volume_status(&fc, &vs);
+ }
+
+ afs_check_for_remote_deletion(&fc, fc.vnode);
+ afs_vnode_commit_status(&fc, vnode, fc.cb_break);
+ ret = afs_end_vnode_operation(&fc);
+ }
+
+ key_put(key);
+
+ if (ret == 0) {
+ if (vs.max_quota == 0)
+ buf->f_blocks = vs.part_max_blocks;
+ else
+ buf->f_blocks = vs.max_quota;
+ buf->f_bavail = buf->f_bfree = buf->f_blocks - vs.blocks_in_use;
+ }
+
+ return ret;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-22 16:17:07 +0000