diff options
Diffstat (limited to 'fs/fuse/inode.c')
-rw-r--r-- | fs/fuse/inode.c | 591 |
1 files changed, 591 insertions, 0 deletions
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c new file mode 100644 index 00000000000..e69a546844d --- /dev/null +++ b/fs/fuse/inode.c @@ -0,0 +1,591 @@ +/* + FUSE: Filesystem in Userspace + Copyright (C) 2001-2005 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/init.h> +#include <linux/module.h> +#include <linux/parser.h> +#include <linux/statfs.h> + +MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); +MODULE_DESCRIPTION("Filesystem in Userspace"); +MODULE_LICENSE("GPL"); + +spinlock_t fuse_lock; +static kmem_cache_t *fuse_inode_cachep; + +#define FUSE_SUPER_MAGIC 0x65735546 + +struct fuse_mount_data { + int fd; + unsigned rootmode; + unsigned user_id; + unsigned group_id; + unsigned fd_present : 1; + unsigned rootmode_present : 1; + unsigned user_id_present : 1; + unsigned group_id_present : 1; + unsigned flags; + unsigned 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; + + fi = get_fuse_inode(inode); + fi->i_time = jiffies - 1; + fi->nodeid = 0; + fi->nlookup = 0; + fi->forget_req = fuse_request_alloc(); + if (!fi->forget_req) { + kmem_cache_free(fuse_inode_cachep, inode); + return NULL; + } + + return inode; +} + +static void fuse_destroy_inode(struct inode *inode) +{ + struct fuse_inode *fi = get_fuse_inode(inode); + 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, u64 nlookup) +{ + struct fuse_forget_in *inarg = &req->misc.forget_in; + inarg->nlookup = nlookup; + 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) +{ + if (inode->i_sb->s_flags & MS_ACTIVE) { + struct fuse_conn *fc = get_fuse_conn(inode); + struct fuse_inode *fi = get_fuse_inode(inode); + fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup); + fi->forget_req = NULL; + } +} + +void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr) +{ + if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size) + invalidate_inode_pages(inode->i_mapping); + + inode->i_ino = attr->ino; + inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777); + inode->i_nlink = attr->nlink; + inode->i_uid = attr->uid; + inode->i_gid = attr->gid; + i_size_write(inode, attr->size); + inode->i_blksize = PAGE_CACHE_SIZE; + inode->i_blocks = attr->blocks; + inode->i_atime.tv_sec = attr->atime; + inode->i_atime.tv_nsec = attr->atimensec; + inode->i_mtime.tv_sec = attr->mtime; + inode->i_mtime.tv_nsec = attr->mtimensec; + inode->i_ctime.tv_sec = attr->ctime; + inode->i_ctime.tv_nsec = attr->ctimensec; +} + +static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr) +{ + inode->i_mode = attr->mode & S_IFMT; + i_size_write(inode, attr->size); + if (S_ISREG(inode->i_mode)) { + fuse_init_common(inode); + fuse_init_file_inode(inode); + } else if (S_ISDIR(inode->i_mode)) + fuse_init_dir(inode); + else if (S_ISLNK(inode->i_mode)) + fuse_init_symlink(inode); + else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || + S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { + fuse_init_common(inode); + init_special_inode(inode, inode->i_mode, + new_decode_dev(attr->rdev)); + } else { + /* Don't let user create weird files */ + inode->i_mode = S_IFREG; + fuse_init_common(inode); + fuse_init_file_inode(inode); + } +} + +static int fuse_inode_eq(struct inode *inode, void *_nodeidp) +{ + unsigned long nodeid = *(unsigned long *) _nodeidp; + if (get_node_id(inode) == nodeid) + return 1; + else + return 0; +} + +static int fuse_inode_set(struct inode *inode, void *_nodeidp) +{ + unsigned long nodeid = *(unsigned long *) _nodeidp; + get_fuse_inode(inode)->nodeid = nodeid; + return 0; +} + +struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid, + int generation, struct fuse_attr *attr) +{ + struct inode *inode; + struct fuse_inode *fi; + struct fuse_conn *fc = get_fuse_conn_super(sb); + int retried = 0; + + retry: + inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid); + if (!inode) + return NULL; + + if ((inode->i_state & I_NEW)) { + inode->i_flags |= S_NOATIME|S_NOCMTIME; + inode->i_generation = generation; + inode->i_data.backing_dev_info = &fc->bdi; + fuse_init_inode(inode, attr); + unlock_new_inode(inode); + } else if ((inode->i_mode ^ attr->mode) & S_IFMT) { + BUG_ON(retried); + /* Inode has changed type, any I/O on the old should fail */ + make_bad_inode(inode); + iput(inode); + retried = 1; + goto retry; + } + + fi = get_fuse_inode(inode); + fi->nlookup ++; + fuse_change_attributes(inode, attr); + return inode; +} + +static void fuse_put_super(struct super_block *sb) +{ + struct fuse_conn *fc = get_fuse_conn_super(sb); + + down_write(&fc->sbput_sem); + while (!list_empty(&fc->background)) + fuse_release_background(list_entry(fc->background.next, + struct fuse_req, bg_entry)); + + spin_lock(&fuse_lock); + fc->mounted = 0; + fc->user_id = 0; + fc->group_id = 0; + fc->flags = 0; + /* Flush all readers on this fs */ + wake_up_all(&fc->waitq); + up_write(&fc->sbput_sem); + fuse_release_conn(fc); + 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 = get_fuse_conn_super(sb); + struct fuse_req *req; + struct fuse_statfs_out outarg; + int err; + + req = fuse_get_request(fc); + if (!req) + return -EINTR; + + 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_USER_ID, + OPT_GROUP_ID, + OPT_DEFAULT_PERMISSIONS, + OPT_ALLOW_OTHER, + OPT_MAX_READ, + OPT_ERR +}; + +static match_table_t tokens = { + {OPT_FD, "fd=%u"}, + {OPT_ROOTMODE, "rootmode=%o"}, + {OPT_USER_ID, "user_id=%u"}, + {OPT_GROUP_ID, "group_id=%u"}, + {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, + {OPT_ALLOW_OTHER, "allow_other"}, + {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->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; + d->fd_present = 1; + break; + + case OPT_ROOTMODE: + if (match_octal(&args[0], &value)) + return 0; + d->rootmode = value; + d->rootmode_present = 1; + break; + + case OPT_USER_ID: + if (match_int(&args[0], &value)) + return 0; + d->user_id = value; + d->user_id_present = 1; + break; + + case OPT_GROUP_ID: + if (match_int(&args[0], &value)) + return 0; + d->group_id = value; + d->group_id_present = 1; + break; + + case OPT_DEFAULT_PERMISSIONS: + d->flags |= FUSE_DEFAULT_PERMISSIONS; + break; + + case OPT_ALLOW_OTHER: + d->flags |= FUSE_ALLOW_OTHER; + break; + + case OPT_MAX_READ: + if (match_int(&args[0], &value)) + return 0; + d->max_read = value; + break; + + default: + return 0; + } + } + + if (!d->fd_present || !d->rootmode_present || + !d->user_id_present || !d->group_id_present) + return 0; + + return 1; +} + +static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt) +{ + struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb); + + seq_printf(m, ",user_id=%u", fc->user_id); + seq_printf(m, ",group_id=%u", fc->group_id); + if (fc->flags & FUSE_DEFAULT_PERMISSIONS) + seq_puts(m, ",default_permissions"); + if (fc->flags & FUSE_ALLOW_OTHER) + seq_puts(m, ",allow_other"); + 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) +{ + fc->count--; + if (!fc->count) + 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)); + init_waitqueue_head(&fc->waitq); + INIT_LIST_HEAD(&fc->pending); + INIT_LIST_HEAD(&fc->processing); + INIT_LIST_HEAD(&fc->unused_list); + INIT_LIST_HEAD(&fc->background); + sema_init(&fc->outstanding_sem, 0); + init_rwsem(&fc->sbput_sem); + for (i = 0; i < FUSE_MAX_OUTSTANDING; i++) { + struct fuse_req *req = fuse_request_alloc(); + if (!req) { + free_conn(fc); + return NULL; + } + list_add(&req->list, &fc->unused_list); + } + fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE; + fc->bdi.unplug_io_fn = default_unplug_io_fn; + fc->reqctr = 0; + } + 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) + return ERR_PTR(-EINVAL); + fc = new_conn(); + if (fc == NULL) + return ERR_PTR(-ENOMEM); + spin_lock(&fuse_lock); + if (file->private_data) { + free_conn(fc); + fc = ERR_PTR(-EINVAL); + } else { + file->private_data = fc; + *get_fuse_conn_super_p(sb) = fc; + fc->mounted = 1; + fc->connected = 1; + fc->count = 2; + } + spin_unlock(&fuse_lock); + return fc; +} + +static struct inode *get_root_inode(struct super_block *sb, unsigned 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); +} + +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_fill_super(struct super_block *sb, void *data, int silent) +{ + struct fuse_conn *fc; + struct inode *root; + struct fuse_mount_data d; + struct file *file; + int err; + + if (!parse_fuse_opt((char *) data, &d)) + return -EINVAL; + + 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; + + file = fget(d.fd); + if (!file) + return -EINVAL; + + fc = get_conn(file, sb); + fput(file); + if (IS_ERR(fc)) + return PTR_ERR(fc); + + fc->flags = d.flags; + fc->user_id = d.user_id; + fc->group_id = d.group_id; + fc->max_read = d.max_read; + if (fc->max_read / PAGE_CACHE_SIZE < fc->bdi.ra_pages) + fc->bdi.ra_pages = fc->max_read / PAGE_CACHE_SIZE; + fc->max_write = FUSE_MAX_IN / 2; + + err = -ENOMEM; + root = get_root_inode(sb, d.rootmode); + if (root == NULL) + goto err; + + sb->s_root = d_alloc_root(root); + if (!sb->s_root) { + iput(root); + goto err; + } + fuse_send_init(fc); + return 0; + + err: + spin_lock(&fuse_lock); + fuse_release_conn(fc); + spin_unlock(&fuse_lock); + return err; +} + +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_fill_super); +} + +static struct file_system_type fuse_fs_type = { + .owner = THIS_MODULE, + .name = "fuse", + .get_sb = fuse_get_sb, + .kill_sb = kill_anon_super, +}; + +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); +} + +static int __init 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 fuse_inode), + 0, SLAB_HWCACHE_ALIGN, + fuse_inode_init_once, NULL); + if (!fuse_inode_cachep) { + unregister_filesystem(&fuse_fs_type); + err = -ENOMEM; + } + } + + return err; +} + +static void fuse_fs_cleanup(void) +{ + unregister_filesystem(&fuse_fs_type); + kmem_cache_destroy(fuse_inode_cachep); +} + +static int __init fuse_init(void) +{ + int res; + + printk("fuse init (API version %i.%i)\n", + FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); + + spin_lock_init(&fuse_lock); + res = fuse_fs_init(); + if (res) + goto err; + + res = fuse_dev_init(); + if (res) + goto err_fs_cleanup; + + return 0; + + err_fs_cleanup: + fuse_fs_cleanup(); + err: + return res; +} + +static void __exit fuse_exit(void) +{ + printk(KERN_DEBUG "fuse exit\n"); + + fuse_fs_cleanup(); + fuse_dev_cleanup(); +} + +module_init(fuse_init); +module_exit(fuse_exit); |