1 files changed, 591 insertions, 0 deletions

diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
new file mode 100644
index 000000000000..e69a546844d0
--- /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);