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-rw-r--r--fs/fuse/file.c132
1 files changed, 132 insertions, 0 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 1d59af3..d9a8289 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -160,6 +160,18 @@ static int fuse_release(struct inode *inode, struct file *file)
return fuse_release_common(inode, file, 0);
}
+/*
+ * It would be nice to scramble the ID space, so that the value of the
+ * files_struct pointer is not exposed to userspace. Symmetric crypto
+ * functions are overkill, since the inverse function doesn't need to
+ * be implemented (though it does have to exist). Is there something
+ * simpler?
+ */
+static inline u64 fuse_lock_owner_id(fl_owner_t id)
+{
+ return (unsigned long) id;
+}
+
static int fuse_flush(struct file *file, fl_owner_t id)
{
struct inode *inode = file->f_dentry->d_inode;
@@ -181,11 +193,13 @@ static int fuse_flush(struct file *file, fl_owner_t id)
memset(&inarg, 0, sizeof(inarg));
inarg.fh = ff->fh;
+ inarg.lock_owner = fuse_lock_owner_id(id);
req->in.h.opcode = FUSE_FLUSH;
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->force = 1;
request_send(fc, req);
err = req->out.h.error;
fuse_put_request(fc, req);
@@ -604,6 +618,122 @@ static int fuse_set_page_dirty(struct page *page)
return 0;
}
+static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
+ struct file_lock *fl)
+{
+ switch (ffl->type) {
+ case F_UNLCK:
+ break;
+
+ case F_RDLCK:
+ case F_WRLCK:
+ if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
+ ffl->end < ffl->start)
+ return -EIO;
+
+ fl->fl_start = ffl->start;
+ fl->fl_end = ffl->end;
+ fl->fl_pid = ffl->pid;
+ break;
+
+ default:
+ return -EIO;
+ }
+ fl->fl_type = ffl->type;
+ return 0;
+}
+
+static void fuse_lk_fill(struct fuse_req *req, struct file *file,
+ const struct file_lock *fl, int opcode, pid_t pid)
+{
+ struct inode *inode = file->f_dentry->d_inode;
+ struct fuse_file *ff = file->private_data;
+ struct fuse_lk_in *arg = &req->misc.lk_in;
+
+ arg->fh = ff->fh;
+ arg->owner = fuse_lock_owner_id(fl->fl_owner);
+ arg->lk.start = fl->fl_start;
+ arg->lk.end = fl->fl_end;
+ arg->lk.type = fl->fl_type;
+ arg->lk.pid = pid;
+ req->in.h.opcode = opcode;
+ req->in.h.nodeid = get_node_id(inode);
+ req->in.numargs = 1;
+ req->in.args[0].size = sizeof(*arg);
+ req->in.args[0].value = arg;
+}
+
+static int fuse_getlk(struct file *file, struct file_lock *fl)
+{
+ struct inode *inode = file->f_dentry->d_inode;
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_req *req;
+ struct fuse_lk_out outarg;
+ int err;
+
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
+ fuse_lk_fill(req, file, fl, FUSE_GETLK, 0);
+ 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)
+ err = convert_fuse_file_lock(&outarg.lk, fl);
+
+ return err;
+}
+
+static int fuse_setlk(struct file *file, struct file_lock *fl)
+{
+ struct inode *inode = file->f_dentry->d_inode;
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ struct fuse_req *req;
+ int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
+ pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
+ int err;
+
+ /* Unlock on close is handled by the flush method */
+ if (fl->fl_flags & FL_CLOSE)
+ return 0;
+
+ req = fuse_get_req(fc);
+ if (IS_ERR(req))
+ return PTR_ERR(req);
+
+ fuse_lk_fill(req, file, fl, opcode, pid);
+ request_send(fc, req);
+ err = req->out.h.error;
+ fuse_put_request(fc, req);
+ return err;
+}
+
+static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
+{
+ struct inode *inode = file->f_dentry->d_inode;
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ int err;
+
+ if (cmd == F_GETLK) {
+ if (fc->no_lock) {
+ if (!posix_test_lock(file, fl, fl))
+ fl->fl_type = F_UNLCK;
+ err = 0;
+ } else
+ err = fuse_getlk(file, fl);
+ } else {
+ if (fc->no_lock)
+ err = posix_lock_file_wait(file, fl);
+ else
+ err = fuse_setlk(file, fl);
+ }
+ return err;
+}
+
static const struct file_operations fuse_file_operations = {
.llseek = generic_file_llseek,
.read = generic_file_read,
@@ -613,6 +743,7 @@ static const struct file_operations fuse_file_operations = {
.flush = fuse_flush,
.release = fuse_release,
.fsync = fuse_fsync,
+ .lock = fuse_file_lock,
.sendfile = generic_file_sendfile,
};
@@ -624,6 +755,7 @@ static const struct file_operations fuse_direct_io_file_operations = {
.flush = fuse_flush,
.release = fuse_release,
.fsync = fuse_fsync,
+ .lock = fuse_file_lock,
/* no mmap and sendfile */
};