/* * Copyright (c) 2002 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@cambridge.redhat.com> * */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/fs.h> #include <linux/pagemap.h> #include "vnode.h" #include "volume.h" #include "cell.h" #include "cmservice.h" #include "fsclient.h" #include "super.h" #include "internal.h" #define AFS_FS_MAGIC 0x6B414653 /* 'kAFS' */ struct afs_mount_params { int rwpath; struct afs_cell *default_cell; struct afs_volume *volume; }; static void afs_i_init_once(void *foo, struct kmem_cache *cachep, unsigned long flags); static int afs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *data, struct vfsmount *mnt); static struct inode *afs_alloc_inode(struct super_block *sb); static void afs_put_super(struct super_block *sb); static void afs_destroy_inode(struct inode *inode); struct file_system_type afs_fs_type = { .owner = THIS_MODULE, .name = "afs", .get_sb = afs_get_sb, .kill_sb = kill_anon_super, .fs_flags = FS_BINARY_MOUNTDATA, }; static const struct super_operations afs_super_ops = { .statfs = simple_statfs, .alloc_inode = afs_alloc_inode, .drop_inode = generic_delete_inode, .destroy_inode = afs_destroy_inode, .clear_inode = afs_clear_inode, .put_super = afs_put_super, }; static struct kmem_cache *afs_inode_cachep; static atomic_t afs_count_active_inodes; /*****************************************************************************/ /* * initialise the filesystem */ int __init afs_fs_init(void) { int ret; _enter(""); afs_timer_init(&afs_mntpt_expiry_timer, &afs_mntpt_expiry_timer_ops); /* 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, afs_i_init_once, NULL); 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); kleave(" = %d", ret); return ret; } kleave(" = 0"); return 0; } /* end afs_fs_init() */ /*****************************************************************************/ /* * clean up the filesystem */ void __exit afs_fs_exit(void) { 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(); } kmem_cache_destroy(afs_inode_cachep); } /* end afs_fs_exit() */ /*****************************************************************************/ /* * check that an argument has a value */ static int want_arg(char **_value, const char *option) { if (!_value || !*_value || !**_value) { printk(KERN_NOTICE "kAFS: %s: argument missing\n", option); return 0; } return 1; } /* end want_arg() */ /*****************************************************************************/ /* * check that there's no subsequent value */ static int want_no_value(char *const *_value, const char *option) { if (*_value && **_value) { printk(KERN_NOTICE "kAFS: %s: Invalid argument: %s\n", option, *_value); return 0; } return 1; } /* end want_no_value() */ /*****************************************************************************/ /* * 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_super_parse_options(struct afs_mount_params *params, char *options, const char **devname) { char *key, *value; int ret; _enter("%s", options); options[PAGE_SIZE - 1] = 0; ret = 0; while ((key = strsep(&options, ",")) != 0) { value = strchr(key, '='); if (value) *value++ = 0; printk("kAFS: KEY: %s, VAL:%s\n", key, value ?: "-"); if (strcmp(key, "rwpath") == 0) { if (!want_no_value(&value, "rwpath")) return -EINVAL; params->rwpath = 1; continue; } else if (strcmp(key, "vol") == 0) { if (!want_arg(&value, "vol")) return -EINVAL; *devname = value; continue; } else if (strcmp(key, "cell") == 0) { if (!want_arg(&value, "cell")) return -EINVAL; afs_put_cell(params->default_cell); ret = afs_cell_lookup(value, strlen(value), ¶ms->default_cell); if (ret < 0) return -EINVAL; continue; } printk("kAFS: Unknown mount option: '%s'\n", key); ret = -EINVAL; goto error; } ret = 0; error: _leave(" = %d", ret); return ret; } /* end afs_super_parse_options() */ /*****************************************************************************/ /* * 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_mount_params *params = data; struct afs_super_info *as = sb->s_fs_info; return as->volume == params->volume; } /* end afs_test_super() */ /*****************************************************************************/ /* * fill in the superblock */ static int afs_fill_super(struct super_block *sb, void *data, int silent) { struct afs_mount_params *params = data; struct afs_super_info *as = NULL; struct afs_fid fid; struct dentry *root = NULL; struct inode *inode = NULL; int ret; kenter(""); /* allocate a superblock info record */ as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL); if (!as) { _leave(" = -ENOMEM"); return -ENOMEM; } afs_get_volume(params->volume); as->volume = params->volume; /* fill in the superblock */ sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize_bits = PAGE_CACHE_SHIFT; sb->s_magic = AFS_FS_MAGIC; sb->s_op = &afs_super_ops; sb->s_fs_info = as; /* allocate the root inode and dentry */ fid.vid = as->volume->vid; fid.vnode = 1; fid.unique = 1; ret = afs_iget(sb, &fid, &inode); if (ret < 0) goto error; ret = -ENOMEM; root = d_alloc_root(inode); if (!root) goto error; sb->s_root = root; kleave(" = 0"); return 0; error: iput(inode); afs_put_volume(as->volume); kfree(as); sb->s_fs_info = NULL; kleave(" = %d", ret); return ret; } /* end afs_fill_super() */ /*****************************************************************************/ /* * get an AFS superblock * - TODO: don't use get_sb_nodev(), but rather call sget() directly */ static int afs_get_sb(struct file_system_type *fs_type, int flags, const char *dev_name, void *options, struct vfsmount *mnt) { struct afs_mount_params params; struct super_block *sb; int ret; _enter(",,%s,%p", dev_name, options); memset(¶ms, 0, sizeof(params)); /* start the cache manager */ ret = afscm_start(); if (ret < 0) { _leave(" = %d", ret); return ret; } /* parse the options */ if (options) { ret = afs_super_parse_options(¶ms, options, &dev_name); if (ret < 0) goto error; if (!dev_name) { printk("kAFS: no volume name specified\n"); ret = -EINVAL; goto error; } } /* parse the device name */ ret = afs_volume_lookup(dev_name, params.default_cell, params.rwpath, ¶ms.volume); if (ret < 0) goto error; /* allocate a deviceless superblock */ sb = sget(fs_type, afs_test_super, set_anon_super, ¶ms); if (IS_ERR(sb)) goto error; sb->s_flags = flags; ret = afs_fill_super(sb, ¶ms, flags & MS_SILENT ? 1 : 0); if (ret < 0) { up_write(&sb->s_umount); deactivate_super(sb); goto error; } sb->s_flags |= MS_ACTIVE; simple_set_mnt(mnt, sb); afs_put_volume(params.volume); afs_put_cell(params.default_cell); _leave(" = 0 [%p]", 0, sb); return 0; error: afs_put_volume(params.volume); afs_put_cell(params.default_cell); afscm_stop(); _leave(" = %d", ret); return ret; } /* end afs_get_sb() */ /*****************************************************************************/ /* * finish the unmounting process on the superblock */ static void afs_put_super(struct super_block *sb) { struct afs_super_info *as = sb->s_fs_info; _enter(""); afs_put_volume(as->volume); afscm_stop(); _leave(""); } /* end afs_put_super() */ /*****************************************************************************/ /* * initialise an inode cache slab element prior to any use */ static void afs_i_init_once(void *_vnode, struct kmem_cache *cachep, unsigned long flags) { struct afs_vnode *vnode = (struct afs_vnode *) _vnode; if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == SLAB_CTOR_CONSTRUCTOR) { memset(vnode, 0, sizeof(*vnode)); inode_init_once(&vnode->vfs_inode); init_waitqueue_head(&vnode->update_waitq); spin_lock_init(&vnode->lock); INIT_LIST_HEAD(&vnode->cb_link); INIT_LIST_HEAD(&vnode->cb_hash_link); afs_timer_init(&vnode->cb_timeout, &afs_vnode_cb_timed_out_ops); } } /* end afs_i_init_once() */ /*****************************************************************************/ /* * allocate an AFS inode struct from our slab cache */ static struct inode *afs_alloc_inode(struct super_block *sb) { struct afs_vnode *vnode; vnode = (struct afs_vnode *) kmem_cache_alloc(afs_inode_cachep, GFP_KERNEL); if (!vnode) return NULL; atomic_inc(&afs_count_active_inodes); memset(&vnode->fid, 0, sizeof(vnode->fid)); memset(&vnode->status, 0, sizeof(vnode->status)); vnode->volume = NULL; vnode->update_cnt = 0; vnode->flags = 0; return &vnode->vfs_inode; } /* end afs_alloc_inode() */ /*****************************************************************************/ /* * destroy an AFS inode struct */ static void afs_destroy_inode(struct inode *inode) { _enter("{%lu}", inode->i_ino); kmem_cache_free(afs_inode_cachep, AFS_FS_I(inode)); atomic_dec(&afs_count_active_inodes); } /* end afs_destroy_inode() */