Orangefs: Clean up pvfs2_devreq_read.
* Kick invalid arguments out early, so handling them does not clutter the code. * Avoid possibility of race by not releasing lock until completely done. * Do not leak ops (memory) in certain error condition. * Check for more error conditions. * Put module name in all error and debug logs. * Document behavior. Signed-off-by: Martin Brandenburg <martin@omnibond.com> Signed-off-by: Mike Marshall <hubcap@omnibond.com>
This commit is contained in:
Martin Brandenburg
committed by
Mike Marshall
Mike Marshall
parent
f0ed4418d4
commit
24c8d0804b
@@ -104,110 +104,137 @@ static ssize_t pvfs2_devreq_read(struct file *file,
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char __user *buf,
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char __user *buf,
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size_t count, loff_t *offset)
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size_t count, loff_t *offset)
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{
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{
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int ret = 0;
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struct pvfs2_kernel_op_s *op, *temp;
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ssize_t len = 0;
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struct pvfs2_kernel_op_s *cur_op = NULL;
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static __s32 magic = PVFS2_DEVREQ_MAGIC;
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__s32 proto_ver = PVFS_KERNEL_PROTO_VERSION;
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__s32 proto_ver = PVFS_KERNEL_PROTO_VERSION;
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static __s32 magic = PVFS2_DEVREQ_MAGIC;
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struct pvfs2_kernel_op_s *cur_op = NULL;
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unsigned long ret;
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/* We do not support blocking IO. */
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if (!(file->f_flags & O_NONBLOCK)) {
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if (!(file->f_flags & O_NONBLOCK)) {
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/* We do not support blocking reads/opens any more */
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gossip_err("orangefs: blocking reads are not supported! (pvfs2-client-core bug)\n");
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gossip_err("pvfs2: blocking reads are not supported! (pvfs2-client-core bug)\n");
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return -EINVAL;
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return -EINVAL;
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} else {
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}
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struct pvfs2_kernel_op_s *op = NULL, *temp = NULL;
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/* get next op (if any) from top of list */
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/*
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spin_lock(&pvfs2_request_list_lock);
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* The client will do an ioctl to find MAX_ALIGNED_DEV_REQ_UPSIZE, then
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list_for_each_entry_safe(op, temp, &pvfs2_request_list, list) {
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* always read with that size buffer.
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__s32 fsid = fsid_of_op(op);
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*/
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/*
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if (count != MAX_ALIGNED_DEV_REQ_UPSIZE) {
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* Check if this op's fsid is known and needs
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gossip_err("orangefs: client-core tried to read wrong size\n");
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* remounting
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return -EINVAL;
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*/
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}
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if (fsid != PVFS_FS_ID_NULL &&
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fs_mount_pending(fsid) == 1) {
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/* Get next op (if any) from top of list. */
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spin_lock(&pvfs2_request_list_lock);
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list_for_each_entry_safe(op, temp, &pvfs2_request_list, list) {
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__s32 fsid;
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/* This lock is held past the end of the loop when we break. */
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spin_lock(&op->lock);
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fsid = fsid_of_op(op);
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if (fsid != PVFS_FS_ID_NULL) {
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int ret;
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/* Skip ops whose filesystem needs to be mounted. */
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ret = fs_mount_pending(fsid);
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if (ret == 1) {
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gossip_debug(GOSSIP_DEV_DEBUG,
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gossip_debug(GOSSIP_DEV_DEBUG,
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"Skipping op tag %llu %s\n",
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"orangefs: skipping op tag %llu %s\n",
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llu(op->tag),
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llu(op->tag), get_opname_string(op));
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get_opname_string(op));
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spin_unlock(&op->lock);
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continue;
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/* Skip ops whose filesystem we don't know about unless
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* it is being mounted. */
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/* XXX: is there a better way to detect this? */
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} else if (ret == -1 &&
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!(op->upcall.type == PVFS2_VFS_OP_FS_MOUNT ||
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op->upcall.type == PVFS2_VFS_OP_GETATTR)) {
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gossip_debug(GOSSIP_DEV_DEBUG,
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"orangefs: skipping op tag %llu %s\n",
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llu(op->tag), get_opname_string(op));
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gossip_err(
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"orangefs: ERROR: fs_mount_pending %d\n",
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fsid);
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spin_unlock(&op->lock);
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continue;
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continue;
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} else {
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/*
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* op does not belong to any particular fsid
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* or already mounted.. let it through
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*/
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cur_op = op;
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spin_lock(&cur_op->lock);
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list_del(&cur_op->list);
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spin_unlock(&cur_op->lock);
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break;
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}
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}
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}
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}
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spin_unlock(&pvfs2_request_list_lock);
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}
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if (cur_op) {
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spin_lock(&cur_op->lock);
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gossip_debug(GOSSIP_DEV_DEBUG,
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"client-core: reading op tag %llu %s\n",
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llu(cur_op->tag), get_opname_string(cur_op));
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if (op_state_in_progress(cur_op) || op_state_serviced(cur_op)) {
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gossip_err("WARNING: Current op already queued...skipping\n");
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} else {
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/*
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* atomically move the operation to the
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* htable_ops_in_progress
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*/
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set_op_state_inprogress(cur_op);
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pvfs2_devreq_add_op(cur_op);
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}
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spin_unlock(&cur_op->lock);
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/* Push the upcall out */
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len = MAX_ALIGNED_DEV_REQ_UPSIZE;
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if ((size_t) len <= count) {
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ret = copy_to_user(buf,
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&proto_ver,
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sizeof(__s32));
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if (ret == 0) {
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ret = copy_to_user(buf + sizeof(__s32),
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&magic,
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sizeof(__s32));
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if (ret == 0) {
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ret = copy_to_user(buf+2 * sizeof(__s32),
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&cur_op->tag,
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sizeof(__u64));
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if (ret == 0) {
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ret = copy_to_user(
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buf +
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2 *
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sizeof(__s32) +
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sizeof(__u64),
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&cur_op->upcall,
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sizeof(struct pvfs2_upcall_s));
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}
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}
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}
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if (ret) {
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gossip_err("Failed to copy data to user space\n");
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len = -EFAULT;
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}
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} else {
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gossip_err
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("Failed to copy data to user space\n");
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len = -EIO;
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}
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} else if (file->f_flags & O_NONBLOCK) {
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/*
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/*
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* if in non-blocking mode, return EAGAIN since no requests are
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* Either this op does not pertain to a filesystem, is mounting
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* ready yet
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* a filesystem, or pertains to a mounted filesystem. Let it
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* through.
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*/
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*/
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len = -EAGAIN;
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cur_op = op;
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break;
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}
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}
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return len;
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/*
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* At this point we either have a valid op and can continue or have not
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* found an op and must ask the client to try again later.
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*/
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if (!cur_op) {
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spin_unlock(&pvfs2_request_list_lock);
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return -EAGAIN;
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}
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gossip_debug(GOSSIP_DEV_DEBUG, "orangefs: reading op tag %llu %s\n",
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llu(cur_op->tag), get_opname_string(cur_op));
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/*
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* Such an op should never be on the list in the first place. If so, we
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* will abort.
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*/
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if (op_state_in_progress(cur_op) || op_state_serviced(cur_op)) {
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gossip_err("orangefs: ERROR: Current op already queued.\n");
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list_del(&cur_op->list);
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spin_unlock(&cur_op->lock);
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spin_unlock(&pvfs2_request_list_lock);
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return -EAGAIN;
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}
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/*
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* Set the operation to be in progress and move it between lists since
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* it has been sent to the client.
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*/
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set_op_state_inprogress(cur_op);
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list_del(&cur_op->list);
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spin_unlock(&pvfs2_request_list_lock);
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pvfs2_devreq_add_op(cur_op);
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spin_unlock(&cur_op->lock);
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/* Push the upcall out. */
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ret = copy_to_user(buf, &proto_ver, sizeof(__s32));
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if (ret != 0)
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goto error;
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ret = copy_to_user(buf+sizeof(__s32), &magic, sizeof(__s32));
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if (ret != 0)
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goto error;
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ret = copy_to_user(buf+2 * sizeof(__s32), &cur_op->tag, sizeof(__u64));
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if (ret != 0)
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goto error;
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ret = copy_to_user(buf+2*sizeof(__s32)+sizeof(__u64), &cur_op->upcall,
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sizeof(struct pvfs2_upcall_s));
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if (ret != 0)
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goto error;
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/* The client only asks to read one size buffer. */
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return MAX_ALIGNED_DEV_REQ_UPSIZE;
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error:
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/*
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* We were unable to copy the op data to the client. Put the op back in
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* list. If client has crashed, the op will be purged later when the
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* device is released.
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*/
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gossip_err("orangefs: Failed to copy data to user space\n");
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spin_lock(&pvfs2_request_list_lock);
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spin_lock(&cur_op->lock);
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set_op_state_waiting(cur_op);
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pvfs2_devreq_remove_op(cur_op->tag);
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list_add(&cur_op->list, &pvfs2_request_list);
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spin_unlock(&cur_op->lock);
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spin_unlock(&pvfs2_request_list_lock);
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return -EFAULT;
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}
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}
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/* Function for writev() callers into the device */
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/* Function for writev() callers into the device */
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