diff options
Diffstat (limited to 'kernel/inode.c')
| -rw-r--r-- | kernel/inode.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/kernel/inode.c b/kernel/inode.c new file mode 100644 index 0000000..ac2d6be --- /dev/null +++ b/kernel/inode.c @@ -0,0 +1,228 @@ +/* + FUSE: Filesystem in Userspace + Copyright (C) 2001 Miklos Szeredi (mszeredi@inf.bme.hu) + + This program can be distributed under the terms of the GNU GPL. + See the file COPYING. +*/ + +#include "fuse_i.h" + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/file.h> + +#define FUSE_SUPER_MAGIC 0x65735546 + +static void fuse_read_inode(struct inode *inode) +{ + /* No op */ +} + +static void send_forget(struct fuse_conn *fc, unsigned long *forget, + unsigned int numforget) +{ + struct fuse_in in = FUSE_IN_INIT; + + in.h.opcode = FUSE_FORGET; + in.h.ino = 0; + in.argsize = numforget * sizeof(unsigned long); + in.arg = forget; + + request_send(fc, &in, NULL); +} + +static int alloc_cleared(struct fuse_conn *fc) +{ + unsigned long *tmp; + + spin_unlock(&fuse_lock); + tmp = kmalloc(sizeof(unsigned long) * MAX_CLEARED, GFP_KERNEL); + spin_lock(&fuse_lock); + + if(!fc->file || fc->cleared != NULL) + kfree(tmp); + else if(!tmp) + printk("fuse_clear_inode: Cannot allocate memory\n"); + else + fc->cleared = tmp; + + return fc->cleared != NULL; +} + +static unsigned long *add_cleared(struct fuse_conn *fc, unsigned long ino) +{ + if(!fc->file || (!fc->cleared && !alloc_cleared(fc))) + return NULL; + + fc->cleared[fc->numcleared] = ino; + fc->numcleared ++; + + if(fc->numcleared == MAX_CLEARED) { + unsigned long *tmp = fc->cleared; + fc->cleared = NULL; + fc->numcleared = 0; + return tmp; + } + + return NULL; +} + +static void fuse_clear_inode(struct inode *inode) +{ + struct fuse_conn *fc = inode->i_sb->u.generic_sbp; + unsigned long *forget; + + spin_lock(&fuse_lock); + forget = add_cleared(fc, inode->i_ino); + spin_unlock(&fuse_lock); + + if(forget) { + send_forget(fc, forget, MAX_CLEARED); + kfree(forget); + } +} + +static void fuse_put_super(struct super_block *sb) +{ + struct fuse_conn *fc = sb->u.generic_sbp; + + spin_lock(&fuse_lock); + fc->sb = NULL; + fuse_release_conn(fc); + spin_unlock(&fuse_lock); + +} + +static struct super_operations fuse_super_operations = { + read_inode: fuse_read_inode, + clear_inode: fuse_clear_inode, + put_super: fuse_put_super, +}; + + +static struct fuse_conn *get_conn(struct fuse_mount_data *d) +{ + struct fuse_conn *fc = NULL; + struct file *file; + struct inode *ino; + + if(d == NULL) { + printk("fuse_read_super: Bad mount data\n"); + return NULL; + } + + if(d->version != FUSE_MOUNT_VERSION) { + printk("fuse_read_super: Bad mount version: %i\n", d->version); + return NULL; + } + + file = fget(d->fd); + ino = NULL; + if(file) + ino = file->f_dentry->d_inode; + + if(!ino || ino->u.generic_ip != proc_fuse_dev) { + printk("fuse_read_super: Bad file: %i\n", d->fd); + goto out; + } + + fc = file->private_data; + + out: + fput(file); + return fc; + +} + +static struct inode *get_root_inode(struct super_block *sb) +{ + struct inode *root ; + + root = iget(sb, 1); + if(root) { + root->i_mode = S_IFDIR; + root->i_uid = 0; + root->i_gid = 0; + root->i_nlink = 2; + root->i_size = 0; + root->i_blksize = 1024; + root->i_blocks = 0; + root->i_atime = CURRENT_TIME; + root->i_mtime = CURRENT_TIME; + root->i_ctime = CURRENT_TIME; + fuse_dir_init(root); + } + + return root; +} + +static struct super_block *fuse_read_super(struct super_block *sb, + void *data, int silent) +{ + struct fuse_conn *fc; + struct inode *root; + + sb->s_blocksize = 1024; + sb->s_blocksize_bits = 10; + sb->s_magic = FUSE_SUPER_MAGIC; + sb->s_op = &fuse_super_operations; + + root = get_root_inode(sb); + if(root == NULL) { + printk("fuse_read_super: failed to get root inode\n"); + return NULL; + } + + spin_lock(&fuse_lock); + fc = get_conn(data); + if(fc == NULL) + goto err; + + if(fc->sb != NULL) { + printk("fuse_read_super: connection %i already mounted\n", + fc->id); + goto err; + } + + sb->u.generic_sbp = fc; + sb->s_root = d_alloc_root(root); + fc->sb = sb; + spin_unlock(&fuse_lock); + + return sb; + + err: + spin_unlock(&fuse_lock); + iput(root); + return NULL; +} + + +static DECLARE_FSTYPE(fuse_fs_type, "fuse", fuse_read_super, 0); + +int fuse_fs_init() +{ + int res; + + res = register_filesystem(&fuse_fs_type); + if(res) + printk("fuse: failed to register filesystem\n"); + + return res; +} + +void fuse_fs_cleanup() +{ + unregister_filesystem(&fuse_fs_type); +} + +/* + * Local Variables: + * indent-tabs-mode: t + * c-basic-offset: 8 + * End: + */ + |