Commit b2d2272f authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds
Browse files

[PATCH] fuse: add bmap support



Add support for the BMAP operation for block device based filesystems.  This
is needed to support swap-files and lilo.
Signed-off-by: default avatarMiklos Szeredi <miklos@szeredi.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent d8091614
......@@ -1024,6 +1024,8 @@ static int fuse_setattr(struct dentry *entry, struct iattr *attr)
if (attr->ia_valid & ATTR_SIZE) {
unsigned long limit;
is_truncate = 1;
if (IS_SWAPFILE(inode))
return -ETXTBSY;
limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
if (limit != RLIM_INFINITY && attr->ia_size > (loff_t) limit) {
send_sig(SIGXFSZ, current, 0);
......
......@@ -754,6 +754,42 @@ static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
return err;
}
static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
{
struct inode *inode = mapping->host;
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_req *req;
struct fuse_bmap_in inarg;
struct fuse_bmap_out outarg;
int err;
if (!inode->i_sb->s_bdev || fc->no_bmap)
return 0;
req = fuse_get_req(fc);
if (IS_ERR(req))
return 0;
memset(&inarg, 0, sizeof(inarg));
inarg.block = block;
inarg.blocksize = inode->i_sb->s_blocksize;
req->in.h.opcode = FUSE_BMAP;
req->in.h.nodeid = get_node_id(inode);
req->in.numargs = 1;
req->in.args[0].size = sizeof(inarg);
req->in.args[0].value = &inarg;
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;
fuse_put_request(fc, req);
if (err == -ENOSYS)
fc->no_bmap = 1;
return err ? 0 : outarg.block;
}
static const struct file_operations fuse_file_operations = {
.llseek = generic_file_llseek,
.read = do_sync_read,
......@@ -787,6 +823,7 @@ static const struct address_space_operations fuse_file_aops = {
.commit_write = fuse_commit_write,
.readpages = fuse_readpages,
.set_page_dirty = fuse_set_page_dirty,
.bmap = fuse_bmap,
};
void fuse_init_file_inode(struct inode *inode)
......
......@@ -339,6 +339,9 @@ struct fuse_conn {
/** Is interrupt not implemented by fs? */
unsigned no_interrupt : 1;
/** Is bmap not implemented by fs? */
unsigned no_bmap : 1;
/** The number of requests waiting for completion */
atomic_t num_waiting;
......
......@@ -132,6 +132,7 @@ enum fuse_opcode {
FUSE_ACCESS = 34,
FUSE_CREATE = 35,
FUSE_INTERRUPT = 36,
FUSE_BMAP = 37,
};
/* The read buffer is required to be at least 8k, but may be much larger */
......@@ -302,6 +303,16 @@ struct fuse_interrupt_in {
__u64 unique;
};
struct fuse_bmap_in {
__u64 block;
__u32 blocksize;
__u32 padding;
};
struct fuse_bmap_out {
__u64 block;
};
struct fuse_in_header {
__u32 len;
__u32 opcode;
......
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