From ed42fe059389daa35a2aa10ec832e9f8d0a9e59e Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 22 Jan 2016 19:47:47 -0500 Subject: orangefs: hopefully saner op refcounting and locking * create with refcount 1 * make op_release() decrement and free if zero (i.e. old put_op() has become that). * mark when submitter has given up waiting; from that point nobody else can move between the lists, change state, etc. * have daemon read/write_iter grab a reference when picking op and *always* give it up in the end * don't put into hash until we know it's been successfully passed to daemon * move op->lock _lower_ than htab_in_progress_lock (and make sure to take it in purge_inprogress_ops()) Signed-off-by: Al Viro Signed-off-by: Mike Marshall --- fs/orangefs/devorangefs-req.c | 112 ++++++++++++++++++++++-------------------- 1 file changed, 60 insertions(+), 52 deletions(-) (limited to 'fs/orangefs/devorangefs-req.c') diff --git a/fs/orangefs/devorangefs-req.c b/fs/orangefs/devorangefs-req.c index 92573d9cc17c..b7a6aa44ce3e 100644 --- a/fs/orangefs/devorangefs-req.c +++ b/fs/orangefs/devorangefs-req.c @@ -43,9 +43,7 @@ static void orangefs_devreq_add_op(struct orangefs_kernel_op_s *op) { int index = hash_func(op->tag, hash_table_size); - spin_lock(&htable_ops_in_progress_lock); list_add_tail(&op->list, &htable_ops_in_progress[index]); - spin_unlock(&htable_ops_in_progress_lock); } static struct orangefs_kernel_op_s *orangefs_devreq_remove_op(__u64 tag) @@ -60,8 +58,9 @@ static struct orangefs_kernel_op_s *orangefs_devreq_remove_op(__u64 tag) next, &htable_ops_in_progress[index], list) { - if (op->tag == tag) { - list_del(&op->list); + if (op->tag == tag && !op_state_purged(op)) { + list_del_init(&op->list); + get_op(op); /* increase ref count. */ spin_unlock(&htable_ops_in_progress_lock); return op; } @@ -127,12 +126,17 @@ static ssize_t orangefs_devreq_read(struct file *file, return -EINVAL; } +restart: /* Get next op (if any) from top of list. */ spin_lock(&orangefs_request_list_lock); list_for_each_entry_safe(op, temp, &orangefs_request_list, list) { __s32 fsid; /* This lock is held past the end of the loop when we break. */ spin_lock(&op->lock); + if (unlikely(op_state_purged(op))) { + spin_unlock(&op->lock); + continue; + } fsid = fsid_of_op(op); if (fsid != ORANGEFS_FS_ID_NULL) { @@ -197,16 +201,10 @@ static ssize_t orangefs_devreq_read(struct file *file, spin_unlock(&orangefs_request_list_lock); return -EAGAIN; } - - /* - * Set the operation to be in progress and move it between lists since - * it has been sent to the client. - */ - set_op_state_inprogress(cur_op); - - list_del(&cur_op->list); + list_del_init(&cur_op->list); + get_op(op); spin_unlock(&orangefs_request_list_lock); - orangefs_devreq_add_op(cur_op); + spin_unlock(&cur_op->lock); /* Push the upcall out. */ @@ -224,6 +222,25 @@ static ssize_t orangefs_devreq_read(struct file *file, if (ret != 0) goto error; + spin_lock(&htable_ops_in_progress_lock); + spin_lock(&cur_op->lock); + if (unlikely(op_state_given_up(cur_op))) { + spin_unlock(&cur_op->lock); + spin_unlock(&htable_ops_in_progress_lock); + op_release(cur_op); + goto restart; + } + + /* + * Set the operation to be in progress and move it between lists since + * it has been sent to the client. + */ + set_op_state_inprogress(cur_op); + orangefs_devreq_add_op(cur_op); + spin_unlock(&cur_op->lock); + spin_unlock(&htable_ops_in_progress_lock); + op_release(cur_op); + /* The client only asks to read one size buffer. */ return MAX_DEV_REQ_UPSIZE; error: @@ -235,11 +252,13 @@ error: gossip_err("orangefs: Failed to copy data to user space\n"); spin_lock(&orangefs_request_list_lock); spin_lock(&cur_op->lock); - set_op_state_waiting(cur_op); - orangefs_devreq_remove_op(cur_op->tag); - list_add(&cur_op->list, &orangefs_request_list); + if (likely(!op_state_given_up(cur_op))) { + set_op_state_waiting(cur_op); + list_add(&cur_op->list, &orangefs_request_list); + } spin_unlock(&cur_op->lock); spin_unlock(&orangefs_request_list_lock); + op_release(cur_op); return -EFAULT; } @@ -278,15 +297,13 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb, __func__, total, (unsigned int) MAX_DEV_REQ_DOWNSIZE); - ret = -EFAULT; - goto out; + return -EFAULT; } n = copy_from_iter(&head, head_size, iter); if (n < head_size) { gossip_err("%s: failed to copy head.\n", __func__); - ret = -EFAULT; - goto out; + return -EFAULT; } if (head.version < ORANGEFS_MINIMUM_USERSPACE_VERSION) { @@ -295,31 +312,26 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb, __func__, head.version, ORANGEFS_MINIMUM_USERSPACE_VERSION); - ret = -EPROTO; - goto out; + return -EPROTO; } if (head.magic != ORANGEFS_DEVREQ_MAGIC) { gossip_err("Error: Device magic number does not match.\n"); - ret = -EPROTO; - goto out; + return -EPROTO; } op = orangefs_devreq_remove_op(head.tag); if (!op) { gossip_err("WARNING: No one's waiting for tag %llu\n", llu(head.tag)); - goto out; + return ret; } - get_op(op); /* increase ref count. */ - n = copy_from_iter(&op->downcall, downcall_size, iter); if (n != downcall_size) { gossip_err("%s: failed to copy downcall.\n", __func__); - put_op(op); ret = -EFAULT; - goto out; + goto Broken; } if (op->downcall.status) @@ -339,9 +351,8 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb, downcall_size, op->downcall.trailer_size, total); - put_op(op); ret = -EFAULT; - goto out; + goto Broken; } /* Only READDIR operations should have trailers. */ @@ -350,9 +361,8 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb, gossip_err("%s: %x operation with trailer.", __func__, op->downcall.type); - put_op(op); ret = -EFAULT; - goto out; + goto Broken; } /* READDIR operations should always have trailers. */ @@ -361,9 +371,8 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb, gossip_err("%s: %x operation with no trailer.", __func__, op->downcall.type); - put_op(op); ret = -EFAULT; - goto out; + goto Broken; } if (op->downcall.type != ORANGEFS_VFS_OP_READDIR) @@ -374,9 +383,8 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb, if (op->downcall.trailer_buf == NULL) { gossip_err("%s: failed trailer vmalloc.\n", __func__); - put_op(op); ret = -ENOMEM; - goto out; + goto Broken; } memset(op->downcall.trailer_buf, 0, op->downcall.trailer_size); n = copy_from_iter(op->downcall.trailer_buf, @@ -385,9 +393,8 @@ static ssize_t orangefs_devreq_write_iter(struct kiocb *iocb, if (n != op->downcall.trailer_size) { gossip_err("%s: failed to copy trailer.\n", __func__); vfree(op->downcall.trailer_buf); - put_op(op); ret = -EFAULT; - goto out; + goto Broken; } wakeup: @@ -404,7 +411,6 @@ wakeup: * the buffers are done being used. */ if (op->downcall.type == ORANGEFS_VFS_OP_FILE_IO) { - int timed_out = 0; DEFINE_WAIT(wait_entry); /* @@ -412,7 +418,8 @@ wakeup: * that this op is done */ spin_lock(&op->lock); - set_op_state_serviced(op); + if (!op_state_given_up(op)) + set_op_state_serviced(op); spin_unlock(&op->lock); while (1) { @@ -435,7 +442,6 @@ wakeup: gossip_debug(GOSSIP_DEV_DEBUG, "%s: timed out.\n", __func__); - timed_out = 1; break; } continue; @@ -450,15 +456,6 @@ wakeup: spin_lock(&op->lock); finish_wait(&op->io_completion_waitq, &wait_entry); spin_unlock(&op->lock); - - /* NOTE: for I/O operations we handle releasing the op - * object except in the case of timeout. the reason we - * can't free the op in timeout cases is that the op - * service logic in the vfs retries operations using - * the same op ptr, thus it can't be freed. - */ - if (!timed_out) - op_release(op); } else { /* * tell the vfs op waiting on a waitqueue that @@ -468,11 +465,22 @@ wakeup: * notification */ spin_lock(&op->lock); - set_op_state_serviced(op); + if (!op_state_given_up(op)) + set_op_state_serviced(op); spin_unlock(&op->lock); } out: + op_release(op); return ret; + +Broken: + spin_lock(&op->lock); + if (!op_state_given_up(op)) { + op->downcall.status = ret; + set_op_state_serviced(op); + } + spin_unlock(&op->lock); + goto out; } /* Returns whether any FS are still pending remounted */ -- cgit