// SPDX-License-Identifier: GPL-2.0 /* * Super block/filesystem wide operations * * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and * Michael Callahan <callahan@maths.ox.ac.uk> * * Rewritten for Linux 2.1. Peter Braam <braam@cs.cmu.edu> * Copyright (C) Carnegie Mellon University */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/string.h> #include <linux/stat.h> #include <linux/errno.h> #include <linux/unistd.h> #include <linux/mutex.h> #include <linux/spinlock.h> #include <linux/file.h> #include <linux/vfs.h> #include <linux/slab.h> #include <linux/pid_namespace.h> #include <linux/uaccess.h> #include <linux/fs.h> #include <linux/vmalloc.h> #include <linux/coda.h> #include <linux/coda_psdev.h> #include "coda_linux.h" #include "coda_cache.h" #include "coda_int.h" /* VFS super_block ops */ static void coda_evict_inode(struct inode *); static void coda_put_super(struct super_block *); static int coda_statfs(struct dentry *dentry, struct kstatfs *buf); static struct kmem_cache * coda_inode_cachep; static struct inode *coda_alloc_inode(struct super_block *sb) { struct coda_inode_info *ei; ei = kmem_cache_alloc(coda_inode_cachep, GFP_KERNEL); if (!ei) return NULL; memset(&ei->c_fid, 0, sizeof(struct CodaFid)); ei->c_flags = 0; ei->c_uid = GLOBAL_ROOT_UID; ei->c_cached_perm = 0; spin_lock_init(&ei->c_lock); return &ei->vfs_inode; } static void coda_i_callback(struct rcu_head *head) { struct inode *inode = container_of(head, struct inode, i_rcu); kmem_cache_free(coda_inode_cachep, ITOC(inode)); } static void coda_destroy_inode(struct inode *inode) { call_rcu(&inode->i_rcu, coda_i_callback); } static void init_once(void *foo) { struct coda_inode_info *ei = (struct coda_inode_info *) foo; inode_init_once(&ei->vfs_inode); } int __init coda_init_inodecache(void) { coda_inode_cachep = kmem_cache_create("coda_inode_cache", sizeof(struct coda_inode_info), 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD| SLAB_ACCOUNT, init_once); if (coda_inode_cachep == NULL) return -ENOMEM; return 0; } void coda_destroy_inodecache(void) { /* * Make sure all delayed rcu free inodes are flushed before we * destroy cache. */ rcu_barrier(); kmem_cache_destroy(coda_inode_cachep); } static int coda_remount(struct super_block *sb, int *flags, char *data) { sync_filesystem(sb); *flags |= SB_NOATIME; return 0; } /* exported operations */ static const struct super_operations coda_super_operations = { .alloc_inode = coda_alloc_inode, .destroy_inode = coda_destroy_inode, .evict_inode = coda_evict_inode, .put_super = coda_put_super, .statfs = coda_statfs, .remount_fs = coda_remount, }; static int get_device_index(struct coda_mount_data *data) { struct fd f; struct inode *inode; int idx; if (data == NULL) { pr_warn("%s: Bad mount data\n", __func__); return -1; } if (data->version != CODA_MOUNT_VERSION) { pr_warn("%s: Bad mount version\n", __func__); return -1; } f = fdget(data->fd); if (!f.file) goto Ebadf; inode = file_inode(f.file); if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) { fdput(f); goto Ebadf; } idx = iminor(inode); fdput(f); if (idx < 0 || idx >= MAX_CODADEVS) { pr_warn("%s: Bad minor number\n", __func__); return -1; } return idx; Ebadf: pr_warn("%s: Bad file\n", __func__); return -1; } static int coda_fill_super(struct super_block *sb, void *data, int silent) { struct inode *root = NULL; struct venus_comm *vc; struct CodaFid fid; int error; int idx; if (task_active_pid_ns(current) != &init_pid_ns) return -EINVAL; idx = get_device_index((struct coda_mount_data *) data); /* Ignore errors in data, for backward compatibility */ if(idx == -1) idx = 0; pr_info("%s: device index: %i\n", __func__, idx); vc = &coda_comms[idx]; mutex_lock(&vc->vc_mutex); if (!vc->vc_inuse) { pr_warn("%s: No pseudo device\n", __func__); error = -EINVAL; goto unlock_out; } if (vc->vc_sb) { pr_warn("%s: Device already mounted\n", __func__); error = -EBUSY; goto unlock_out; } vc->vc_sb = sb; mutex_unlock(&vc->vc_mutex); sb->s_fs_info = vc; sb->s_flags |= SB_NOATIME; sb->s_blocksize = 4096; /* XXXXX what do we put here?? */ sb->s_blocksize_bits = 12; sb->s_magic = CODA_SUPER_MAGIC; sb->s_op = &coda_super_operations; sb->s_d_op = &coda_dentry_operations; error = super_setup_bdi(sb); if (error) goto error; /* get root fid from Venus: this needs the root inode */ error = venus_rootfid(sb, &fid); if ( error ) { pr_warn("%s: coda_get_rootfid failed with %d\n", __func__, error); goto error; } pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid)); /* make root inode */ root = coda_cnode_make(&fid, sb); if (IS_ERR(root)) { error = PTR_ERR(root); pr_warn("Failure of coda_cnode_make for root: error %d\n", error); goto error; } pr_info("%s: rootinode is %ld dev %s\n", __func__, root->i_ino, root->i_sb->s_id); sb->s_root = d_make_root(root); if (!sb->s_root) { error = -EINVAL; goto error; } return 0; error: mutex_lock(&vc->vc_mutex); vc->vc_sb = NULL; sb->s_fs_info = NULL; unlock_out: mutex_unlock(&vc->vc_mutex); return error; } static void coda_put_super(struct super_block *sb) { struct venus_comm *vcp = coda_vcp(sb); mutex_lock(&vcp->vc_mutex); vcp->vc_sb = NULL; sb->s_fs_info = NULL; mutex_unlock(&vcp->vc_mutex); pr_info("Bye bye.\n"); } static void coda_evict_inode(struct inode *inode) { truncate_inode_pages_final(&inode->i_data); clear_inode(inode); coda_cache_clear_inode(inode); } int coda_getattr(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int flags) { int err = coda_revalidate_inode(d_inode(path->dentry)); if (!err) generic_fillattr(d_inode(path->dentry), stat); return err; } int coda_setattr(struct dentry *de, struct iattr *iattr) { struct inode *inode = d_inode(de); struct coda_vattr vattr; int error; memset(&vattr, 0, sizeof(vattr)); inode->i_ctime = current_time(inode); coda_iattr_to_vattr(iattr, &vattr); vattr.va_type = C_VNON; /* cannot set type */ /* Venus is responsible for truncating the container-file!!! */ error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr); if (!error) { coda_vattr_to_iattr(inode, &vattr); coda_cache_clear_inode(inode); } return error; } const struct inode_operations coda_file_inode_operations = { .permission = coda_permission, .getattr = coda_getattr, .setattr = coda_setattr, }; static int coda_statfs(struct dentry *dentry, struct kstatfs *buf) { int error; error = venus_statfs(dentry, buf); if (error) { /* fake something like AFS does */ buf->f_blocks = 9000000; buf->f_bfree = 9000000; buf->f_bavail = 9000000; buf->f_files = 9000000; buf->f_ffree = 9000000; } /* and fill in the rest */ buf->f_type = CODA_SUPER_MAGIC; buf->f_bsize = 4096; buf->f_namelen = CODA_MAXNAMLEN; return 0; } /* init_coda: used by filesystems.c to register coda */ static struct dentry *coda_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { return mount_nodev(fs_type, flags, data, coda_fill_super); } struct file_system_type coda_fs_type = { .owner = THIS_MODULE, .name = "coda", .mount = coda_mount, .kill_sb = kill_anon_super, .fs_flags = FS_BINARY_MOUNTDATA, }; MODULE_ALIAS_FS("coda");