struct fuse_req *fuse_get_req(struct fuse_conn *fc)
{
struct fuse_req *req;
sigset_t oldset;
int intr;
int err;
atomic_inc(&fc->num_waiting);
block_sigs(&oldset);
intr = wait_event_interruptible(fc->blocked_waitq, !fc->blocked);
restore_sigs(&oldset);
err = -EINTR;
if (intr)
goto out;
err = -ENOTCONN;
if (!fc->connected)
goto out;
req = fuse_request_alloc();
err = -ENOMEM;
if (!req)
goto out;
fuse_req_init_context(req);
req->waiting = 1;
return req;
out:
atomic_dec(&fc->num_waiting);
return ERR_PTR(err);
}
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);
}
#ifdef KERNEL_2_6_6_PLUS
fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
fc->bdi.unplug_io_fn = default_unplug_io_fn;
#endif
fc->reqctr = 0;
}
return fc;
}
static struct inode *fuse_alloc_inode(struct super_block *sb)
{
struct inode *inode;
struct fuse_inode *fi;
inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
if (!inode)
return NULL;
fi = get_fuse_inode(inode);
fi->i_time = 0;
fi->nodeid = 0;
fi->nlookup = 0;
fi->attr_version = 0;
fi->writectr = 0;
fi->orig_ino = 0;
INIT_LIST_HEAD(&fi->write_files);
INIT_LIST_HEAD(&fi->queued_writes);
INIT_LIST_HEAD(&fi->writepages);
init_waitqueue_head(&fi->page_waitq);
fi->forget_req = fuse_request_alloc();
if (!fi->forget_req) {
kmem_cache_free(fuse_inode_cachep, inode);
return NULL;
}
return inode;
}
struct fuse_file *fuse_file_alloc(void)
{
struct fuse_file *ff;
ff = kmalloc(sizeof(struct fuse_file), GFP_KERNEL);
if (ff) {
ff->release_req = fuse_request_alloc();
if (!ff->release_req) {
kfree(ff);
ff = NULL;
}
}
return ff;
}
/*
* Gets a requests for a file operation, always succeeds
*
* This is used for sending the FLUSH request, which must get to
* userspace, due to POSIX locks which may need to be unlocked.
*
* If allocation fails due to OOM, use the reserved request in
* fuse_file.
*
* This is very unlikely to deadlock accidentally, since the
* filesystem should not have it's own file open. If deadlock is
* intentional, it can still be broken by "aborting" the filesystem.
*/
struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file)
{
struct fuse_req *req;
atomic_inc(&fc->num_waiting);
wait_event(fc->blocked_waitq, !fc->blocked);
req = fuse_request_alloc();
if (!req)
req = get_reserved_req(fc, file);
fuse_req_init_context(req);
req->waiting = 1;
return req;
}
static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
bool for_background)
{
struct fuse_req *req;
int err;
atomic_inc(&fc->num_waiting);
if (fuse_block_alloc(fc, for_background)) {
sigset_t oldset;
int intr;
block_sigs(&oldset);
intr = wait_event_interruptible_exclusive(fc->blocked_waitq,
!fuse_block_alloc(fc, for_background));
restore_sigs(&oldset);
err = -EINTR;
if (intr)
goto out;
}
err = -ENOTCONN;
if (!fc->connected)
goto out;
req = fuse_request_alloc(npages);
err = -ENOMEM;
if (!req) {
if (for_background)
wake_up(&fc->blocked_waitq);
goto out;
}
fuse_req_init_context(req);
req->waiting = 1;
req->background = for_background;
return req;
out:
atomic_dec(&fc->num_waiting);
return ERR_PTR(err);
}
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 = 0;
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 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 = 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 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;
struct dentry *root_dentry;
struct fuse_req *init_req;
int err;
int is_bdev = sb->s_bdev != NULL;
if (sb->s_flags & MS_MANDLOCK)
return -EINVAL;
if (!parse_fuse_opt((char *) data, &d, is_bdev))
return -EINVAL;
if (is_bdev) {
#ifdef CONFIG_BLOCK
if (!sb_set_blocksize(sb, d.blksize))
return -EINVAL;
#endif
} else {
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;
sb->s_export_op = &fuse_export_operations;
file = fget(d.fd);
if (!file)
return -EINVAL;
if (file->f_op != &fuse_dev_operations)
return -EINVAL;
fc = new_conn(sb);
if (!fc)
return -ENOMEM;
fc->flags = d.flags;
fc->user_id = d.user_id;
fc->group_id = d.group_id;
fc->max_read = max_t(unsigned, 4096, d.max_read);
/* Used by get_root_inode() */
sb->s_fs_info = fc;
err = -ENOMEM;
root = get_root_inode(sb, d.rootmode);
if (!root)
goto err;
root_dentry = d_alloc_root(root);
if (!root_dentry) {
iput(root);
goto err;
}
init_req = fuse_request_alloc();
if (!init_req)
goto err_put_root;
if (is_bdev) {
fc->destroy_req = fuse_request_alloc();
if (!fc->destroy_req)
goto err_free_init_req;
}
mutex_lock(&fuse_mutex);
err = -EINVAL;
if (file->private_data)
goto err_unlock;
err = fuse_ctl_add_conn(fc);
if (err)
goto err_unlock;
list_add_tail(&fc->entry, &fuse_conn_list);
sb->s_root = root_dentry;
fc->connected = 1;
file->private_data = fuse_conn_get(fc);
mutex_unlock(&fuse_mutex);
/*
* atomic_dec_and_test() in fput() provides the necessary
* memory barrier for file->private_data to be visible on all
* CPUs after this
*/
fput(file);
fuse_send_init(fc, init_req);
return 0;
err_unlock:
mutex_unlock(&fuse_mutex);
err_free_init_req:
fuse_request_free(init_req);
err_put_root:
dput(root_dentry);
err:
fput(file);
fuse_conn_put(fc);
return err;
}
