| /* |
| FUSE: Filesystem in Userspace |
| Copyright (C) 2001-2004 Miklos Szeredi <miklos@szeredi.hu> |
| |
| This program can be distributed under the terms of the GNU GPL. |
| See the file COPYING. |
| */ |
| |
| #include "fuse_i.h" |
| |
| #include <linux/pagemap.h> |
| #include <linux/slab.h> |
| #include <linux/file.h> |
| #include <linux/mount.h> |
| #include <linux/seq_file.h> |
| #include <linux/module.h> |
| #ifdef KERNEL_2_6 |
| #include <linux/moduleparam.h> |
| #include <linux/parser.h> |
| #include <linux/statfs.h> |
| #else |
| #include <linux/proc_fs.h> |
| #include "compat/parser.h" |
| #endif |
| |
| static kmem_cache_t *fuse_inode_cachep; |
| |
| static int user_allow_other; |
| #ifdef KERNEL_2_6 |
| module_param(user_allow_other, int, 0644); |
| #else |
| MODULE_PARM(user_allow_other, "i"); |
| #endif |
| MODULE_PARM_DESC(user_allow_other, "Allow non root user to specify the \"allow_other\" or \"allow_root\" mount options"); |
| |
| #define FUSE_SUPER_MAGIC 0x65735546 |
| |
| #ifndef KERNEL_2_6 |
| #define kstatfs statfs |
| #endif |
| #ifndef FS_SAFE |
| #define FS_SAFE 0 |
| #endif |
| #ifndef MAX_LFS_FILESIZE |
| #define MAX_LFS_FILESIZE (((u64)PAGE_CACHE_SIZE << (BITS_PER_LONG-1))-1) |
| #endif |
| struct fuse_mount_data { |
| int fd; |
| unsigned int rootmode; |
| unsigned int uid; |
| unsigned int flags; |
| unsigned int max_read; |
| }; |
| |
| static struct inode *fuse_alloc_inode(struct super_block *sb) |
| { |
| struct inode *inode; |
| struct fuse_inode *fi; |
| |
| inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL); |
| if (!inode) |
| return NULL; |
| |
| #ifndef KERNEL_2_6 |
| inode->u.generic_ip = NULL; |
| #endif |
| |
| fi = INO_FI(inode); |
| memset(fi, 0, sizeof(*fi)); |
| fi->forget_req = fuse_request_alloc(); |
| if (!fi->forget_req) { |
| kmem_cache_free(fuse_inode_cachep, inode); |
| return NULL; |
| } |
| init_rwsem(&fi->write_sem); |
| INIT_LIST_HEAD(&fi->write_files); |
| |
| return inode; |
| } |
| |
| static void fuse_destroy_inode(struct inode *inode) |
| { |
| struct fuse_inode *fi = INO_FI(inode); |
| BUG_ON(!list_empty(&fi->write_files)); |
| if (fi->forget_req) |
| fuse_request_free(fi->forget_req); |
| kmem_cache_free(fuse_inode_cachep, inode); |
| } |
| |
| static void fuse_read_inode(struct inode *inode) |
| { |
| /* No op */ |
| } |
| |
| void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req, |
| unsigned long nodeid, int version) |
| { |
| struct fuse_forget_in *inarg = &req->misc.forget_in; |
| inarg->version = version; |
| req->in.h.opcode = FUSE_FORGET; |
| req->in.h.nodeid = nodeid; |
| req->in.numargs = 1; |
| req->in.args[0].size = sizeof(struct fuse_forget_in); |
| req->in.args[0].value = inarg; |
| request_send_noreply(fc, req); |
| } |
| |
| static void fuse_clear_inode(struct inode *inode) |
| { |
| struct fuse_conn *fc = INO_FC(inode); |
| |
| if (fc) { |
| struct fuse_inode *fi = INO_FI(inode); |
| fuse_send_forget(fc, fi->forget_req, fi->nodeid, inode->i_version); |
| fi->forget_req = NULL; |
| } |
| } |
| |
| static void fuse_put_super(struct super_block *sb) |
| { |
| struct fuse_conn *fc = SB_FC(sb); |
| |
| down(&fc->sb_sem); |
| spin_lock(&fuse_lock); |
| fc->sb = NULL; |
| up(&fc->sb_sem); |
| fc->uid = 0; |
| fc->flags = 0; |
| /* Flush all readers on this fs */ |
| wake_up_all(&fc->waitq); |
| fuse_release_conn(fc); |
| SB_FC(sb) = NULL; |
| spin_unlock(&fuse_lock); |
| } |
| |
| static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr) |
| { |
| stbuf->f_type = FUSE_SUPER_MAGIC; |
| stbuf->f_bsize = attr->bsize; |
| stbuf->f_blocks = attr->blocks; |
| stbuf->f_bfree = attr->bfree; |
| stbuf->f_bavail = attr->bavail; |
| stbuf->f_files = attr->files; |
| stbuf->f_ffree = attr->ffree; |
| stbuf->f_namelen = attr->namelen; |
| /* fsid is left zero */ |
| } |
| |
| static int fuse_statfs(struct super_block *sb, struct kstatfs *buf) |
| { |
| struct fuse_conn *fc = SB_FC(sb); |
| struct fuse_req *req; |
| struct fuse_statfs_out outarg; |
| int err; |
| |
| req = fuse_get_request(fc); |
| if (!req) |
| return -ERESTARTSYS; |
| |
| req->in.numargs = 0; |
| req->in.h.opcode = FUSE_STATFS; |
| req->out.numargs = 1; |
| req->out.args[0].size = sizeof(outarg); |
| req->out.args[0].value = &outarg; |
| request_send(fc, req); |
| err = req->out.h.error; |
| if (!err) |
| convert_fuse_statfs(buf, &outarg.st); |
| fuse_put_request(fc, req); |
| return err; |
| } |
| |
| enum { |
| OPT_FD, |
| OPT_ROOTMODE, |
| OPT_UID, |
| OPT_DEFAULT_PERMISSIONS, |
| OPT_ALLOW_OTHER, |
| OPT_ALLOW_ROOT, |
| OPT_KERNEL_CACHE, |
| #ifndef FUSE_MAINLINE |
| OPT_LARGE_READ, |
| #endif |
| OPT_DIRECT_IO, |
| OPT_MAX_READ, |
| OPT_ERR |
| }; |
| |
| static match_table_t tokens = { |
| {OPT_FD, "fd=%u"}, |
| {OPT_ROOTMODE, "rootmode=%o"}, |
| {OPT_UID, "uid=%u"}, |
| {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, |
| {OPT_ALLOW_OTHER, "allow_other"}, |
| {OPT_ALLOW_ROOT, "allow_root"}, |
| {OPT_KERNEL_CACHE, "kernel_cache"}, |
| #ifndef FUSE_MAINLINE |
| {OPT_LARGE_READ, "large_read"}, |
| #endif |
| {OPT_DIRECT_IO, "direct_io"}, |
| {OPT_MAX_READ, "max_read=%u"}, |
| {OPT_ERR, NULL} |
| }; |
| |
| static int parse_fuse_opt(char *opt, struct fuse_mount_data *d) |
| { |
| char *p; |
| memset(d, 0, sizeof(struct fuse_mount_data)); |
| d->fd = -1; |
| d->max_read = ~0; |
| |
| while ((p = strsep(&opt, ",")) != NULL) { |
| int token; |
| int value; |
| substring_t args[MAX_OPT_ARGS]; |
| if (!*p) |
| continue; |
| |
| token = match_token(p, tokens, args); |
| switch (token) { |
| case OPT_FD: |
| if (match_int(&args[0], &value)) |
| return 0; |
| d->fd = value; |
| break; |
| |
| case OPT_ROOTMODE: |
| if (match_octal(&args[0], &value)) |
| return 0; |
| d->rootmode = value; |
| break; |
| |
| case OPT_UID: |
| if (match_int(&args[0], &value)) |
| return 0; |
| d->uid = value; |
| break; |
| |
| case OPT_DEFAULT_PERMISSIONS: |
| d->flags |= FUSE_DEFAULT_PERMISSIONS; |
| break; |
| |
| case OPT_ALLOW_OTHER: |
| d->flags |= FUSE_ALLOW_OTHER; |
| break; |
| |
| case OPT_ALLOW_ROOT: |
| d->flags |= FUSE_ALLOW_ROOT; |
| break; |
| |
| case OPT_KERNEL_CACHE: |
| d->flags |= FUSE_KERNEL_CACHE; |
| break; |
| |
| #ifndef FUSE_MAINLINE |
| case OPT_LARGE_READ: |
| #ifndef KERNEL_2_6 |
| d->flags |= FUSE_LARGE_READ; |
| #else |
| { |
| static int warned = 0; |
| if (!warned) { |
| printk("fuse: large_read option is deprecated for 2.6 kernels\n"); |
| warned = 1; |
| } |
| } |
| #endif |
| break; |
| #endif |
| case OPT_DIRECT_IO: |
| d->flags |= FUSE_DIRECT_IO; |
| break; |
| |
| case OPT_MAX_READ: |
| if (match_int(&args[0], &value)) |
| return 0; |
| d->max_read = value; |
| break; |
| |
| default: |
| return 0; |
| } |
| } |
| if (d->fd == -1) |
| return 0; |
| |
| return 1; |
| } |
| |
| static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt) |
| { |
| struct fuse_conn *fc = SB_FC(mnt->mnt_sb); |
| |
| seq_printf(m, ",uid=%u", fc->uid); |
| if (fc->flags & FUSE_DEFAULT_PERMISSIONS) |
| seq_puts(m, ",default_permissions"); |
| if (fc->flags & FUSE_ALLOW_OTHER) |
| seq_puts(m, ",allow_other"); |
| if (fc->flags & FUSE_ALLOW_ROOT) |
| seq_puts(m, ",allow_root"); |
| if (fc->flags & FUSE_KERNEL_CACHE) |
| seq_puts(m, ",kernel_cache"); |
| #ifndef KERNEL_2_6 |
| if (fc->flags & FUSE_LARGE_READ) |
| seq_puts(m, ",large_read"); |
| #endif |
| if (fc->flags & FUSE_DIRECT_IO) |
| seq_puts(m, ",direct_io"); |
| if (fc->max_read != ~0) |
| seq_printf(m, ",max_read=%u", fc->max_read); |
| return 0; |
| } |
| |
| static void free_conn(struct fuse_conn *fc) |
| { |
| while (!list_empty(&fc->unused_list)) { |
| struct fuse_req *req; |
| req = list_entry(fc->unused_list.next, struct fuse_req, list); |
| list_del(&req->list); |
| fuse_request_free(req); |
| } |
| kfree(fc); |
| } |
| |
| /* Must be called with the fuse lock held */ |
| void fuse_release_conn(struct fuse_conn *fc) |
| { |
| if (!fc->sb && !fc->file) |
| free_conn(fc); |
| } |
| |
| static struct fuse_conn *new_conn(void) |
| { |
| struct fuse_conn *fc; |
| |
| fc = kmalloc(sizeof(*fc), GFP_KERNEL); |
| if (fc != NULL) { |
| int i; |
| memset(fc, 0, sizeof(*fc)); |
| fc->sb = NULL; |
| fc->file = NULL; |
| fc->flags = 0; |
| fc->uid = 0; |
| init_waitqueue_head(&fc->waitq); |
| INIT_LIST_HEAD(&fc->pending); |
| INIT_LIST_HEAD(&fc->processing); |
| INIT_LIST_HEAD(&fc->unused_list); |
| sema_init(&fc->unused_sem, FUSE_MAX_OUTSTANDING); |
| sema_init(&fc->sb_sem, 1); |
| for (i = 0; i < FUSE_MAX_OUTSTANDING; i++) { |
| struct fuse_req *req = fuse_request_alloc(); |
| if (!req) { |
| free_conn(fc); |
| return NULL; |
| } |
| req->preallocated = 1; |
| list_add(&req->list, &fc->unused_list); |
| } |
| #ifdef KERNEL_2_6 |
| fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE; |
| fc->bdi.unplug_io_fn = default_unplug_io_fn; |
| #endif |
| fc->reqctr = 1; |
| } |
| return fc; |
| } |
| |
| static struct fuse_conn *get_conn(struct file *file, struct super_block *sb) |
| { |
| struct fuse_conn *fc; |
| |
| if (file->f_op != &fuse_dev_operations) { |
| printk("FUSE: bad communication file descriptor\n"); |
| return NULL; |
| } |
| fc = new_conn(); |
| if (fc == NULL) { |
| printk("FUSE: failed to allocate connection data\n"); |
| return NULL; |
| } |
| spin_lock(&fuse_lock); |
| if (file->private_data) { |
| printk("fuse_read_super: connection already mounted\n"); |
| free_conn(fc); |
| fc = NULL; |
| } else { |
| file->private_data = fc; |
| fc->sb = sb; |
| fc->file = file; |
| } |
| spin_unlock(&fuse_lock); |
| return fc; |
| } |
| |
| static struct inode *get_root_inode(struct super_block *sb, unsigned int mode) |
| { |
| struct fuse_attr attr; |
| memset(&attr, 0, sizeof(attr)); |
| |
| attr.mode = mode; |
| attr.ino = FUSE_ROOT_ID; |
| return fuse_iget(sb, 1, 0, &attr, 0); |
| } |
| |
| #ifdef KERNEL_2_6 |
| static struct dentry *fuse_get_dentry(struct super_block *sb, void *vobjp) |
| { |
| __u32 *objp = vobjp; |
| unsigned long nodeid = objp[0]; |
| __u32 generation = objp[1]; |
| struct inode *inode; |
| struct dentry *entry; |
| |
| if (nodeid == 0) |
| return ERR_PTR(-ESTALE); |
| |
| inode = fuse_ilookup(sb, nodeid); |
| if (!inode || inode->i_generation != generation) |
| return ERR_PTR(-ESTALE); |
| |
| entry = d_alloc_anon(inode); |
| if (!entry) { |
| iput(inode); |
| return ERR_PTR(-ENOMEM); |
| } |
| |
| return entry; |
| } |
| |
| static int fuse_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len, |
| int connectable) |
| { |
| struct inode *inode = dentry->d_inode; |
| struct fuse_inode *fi = INO_FI(inode); |
| int len = *max_len; |
| int type = 1; |
| |
| if (len < 2 || (connectable && len < 4)) |
| return 255; |
| |
| len = 2; |
| fh[0] = fi->nodeid; |
| fh[1] = inode->i_generation; |
| if (connectable && !S_ISDIR(inode->i_mode)) { |
| struct inode *parent; |
| struct fuse_inode *parent_fi; |
| |
| spin_lock(&dentry->d_lock); |
| parent = dentry->d_parent->d_inode; |
| parent_fi = INO_FI(parent); |
| fh[2] = parent_fi->nodeid; |
| fh[3] = parent->i_generation; |
| spin_unlock(&dentry->d_lock); |
| len = 4; |
| type = 2; |
| } |
| *max_len = len; |
| return type; |
| } |
| |
| |
| static struct export_operations fuse_export_operations = { |
| .get_dentry = fuse_get_dentry, |
| .encode_fh = fuse_encode_fh, |
| }; |
| #endif |
| |
| static struct super_operations fuse_super_operations = { |
| .alloc_inode = fuse_alloc_inode, |
| .destroy_inode = fuse_destroy_inode, |
| .read_inode = fuse_read_inode, |
| .clear_inode = fuse_clear_inode, |
| .put_super = fuse_put_super, |
| .statfs = fuse_statfs, |
| .show_options = fuse_show_options, |
| }; |
| |
| static int fuse_read_super(struct super_block *sb, void *data, int silent) |
| { |
| struct fuse_conn *fc; |
| struct inode *root; |
| struct fuse_mount_data d; |
| struct file *file; |
| |
| if (!parse_fuse_opt((char *) data, &d)) |
| return -EINVAL; |
| |
| if (!user_allow_other && |
| (d.flags & (FUSE_ALLOW_OTHER | FUSE_ALLOW_ROOT)) && |
| current->uid != 0) |
| return -EPERM; |
| |
| sb->s_blocksize = PAGE_CACHE_SIZE; |
| sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
| sb->s_magic = FUSE_SUPER_MAGIC; |
| sb->s_op = &fuse_super_operations; |
| sb->s_maxbytes = MAX_LFS_FILESIZE; |
| #ifdef KERNEL_2_6 |
| sb->s_export_op = &fuse_export_operations; |
| #endif |
| |
| file = fget(d.fd); |
| if (!file) |
| return -EINVAL; |
| |
| fc = get_conn(file, sb); |
| fput(file); |
| if (fc == NULL) |
| return -EINVAL; |
| |
| fc->flags = d.flags; |
| fc->uid = d.uid; |
| fc->max_read = d.max_read; |
| #ifdef KERNEL_2_6 |
| if (fc->max_read / PAGE_CACHE_SIZE < fc->bdi.ra_pages) |
| fc->bdi.ra_pages = fc->max_read / PAGE_CACHE_SIZE; |
| #endif |
| fc->max_write = FUSE_MAX_IN / 2; |
| |
| SB_FC(sb) = fc; |
| |
| root = get_root_inode(sb, d.rootmode); |
| if (root == NULL) { |
| printk("fuse_read_super: failed to get root inode\n"); |
| goto err; |
| } |
| |
| sb->s_root = d_alloc_root(root); |
| if (!sb->s_root) { |
| iput(root); |
| goto err; |
| } |
| |
| return 0; |
| |
| err: |
| down(&fc->sb_sem); |
| spin_lock(&fuse_lock); |
| fc->sb = NULL; |
| up(&fc->sb_sem); |
| fuse_release_conn(fc); |
| spin_unlock(&fuse_lock); |
| SB_FC(sb) = NULL; |
| return -EINVAL; |
| } |
| |
| #ifdef KERNEL_2_6 |
| static struct super_block *fuse_get_sb(struct file_system_type *fs_type, |
| int flags, const char *dev_name, |
| void *raw_data) |
| { |
| return get_sb_nodev(fs_type, flags, raw_data, fuse_read_super); |
| } |
| |
| static struct file_system_type fuse_fs_type = { |
| .owner = THIS_MODULE, |
| .name = "fuse", |
| .get_sb = fuse_get_sb, |
| .kill_sb = kill_anon_super, |
| #ifndef FUSE_MAINLINE |
| .fs_flags = FS_SAFE, |
| #endif |
| }; |
| #else |
| static struct super_block *fuse_read_super_compat(struct super_block *sb, |
| void *data, int silent) |
| { |
| int err = fuse_read_super(sb, data, silent); |
| if (err) |
| return NULL; |
| else |
| return sb; |
| } |
| |
| static DECLARE_FSTYPE(fuse_fs_type, "fuse", fuse_read_super_compat, 0); |
| #endif |
| |
| static void fuse_inode_init_once(void * foo, kmem_cache_t * cachep, |
| unsigned long flags) |
| { |
| struct inode * inode = foo; |
| |
| if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) == |
| SLAB_CTOR_CONSTRUCTOR) |
| inode_init_once(inode); |
| } |
| |
| int fuse_fs_init(void) |
| { |
| int err; |
| |
| err = register_filesystem(&fuse_fs_type); |
| if (err) |
| printk("fuse: failed to register filesystem\n"); |
| else { |
| fuse_inode_cachep = kmem_cache_create("fuse_inode", |
| sizeof(struct inode) + sizeof(struct fuse_inode) , |
| 0, SLAB_HWCACHE_ALIGN, |
| fuse_inode_init_once, NULL); |
| if (!fuse_inode_cachep) { |
| unregister_filesystem(&fuse_fs_type); |
| err = -ENOMEM; |
| } |
| } |
| |
| return err; |
| } |
| |
| void fuse_fs_cleanup(void) |
| { |
| unregister_filesystem(&fuse_fs_type); |
| kmem_cache_destroy(fuse_inode_cachep); |
| } |