Merge tag 'io_uring-5.10-2020-11-20' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe:
"Mostly regression or stable fodder:
- Disallow async path resolution of /proc/self
- Tighten constraints for segmented async buffered reads
- Fix double completion for a retry error case
- Fix for fixed file life times (Pavel)"
* tag 'io_uring-5.10-2020-11-20' of git://git.kernel.dk/linux-block:
io_uring: order refnode recycling
io_uring: get an active ref_node from files_data
io_uring: don't double complete failed reissue request
mm: never attempt async page lock if we've transferred data already
io_uring: handle -EOPNOTSUPP on path resolution
proc: don't allow async path resolution of /proc/self components
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 4ead291..a8c136a 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -205,6 +205,7 @@
struct list_head file_list;
struct fixed_file_data *file_data;
struct llist_node llist;
+ bool done;
};
struct fixed_file_data {
@@ -478,6 +479,7 @@
struct io_open {
struct file *file;
int dfd;
+ bool ignore_nonblock;
struct filename *filename;
struct open_how how;
unsigned long nofile;
@@ -2577,7 +2579,6 @@
}
end_req:
req_set_fail_links(req);
- io_req_complete(req, ret);
return false;
}
#endif
@@ -3795,6 +3796,7 @@
return ret;
}
req->open.nofile = rlimit(RLIMIT_NOFILE);
+ req->open.ignore_nonblock = false;
req->flags |= REQ_F_NEED_CLEANUP;
return 0;
}
@@ -3838,7 +3840,7 @@
struct file *file;
int ret;
- if (force_nonblock)
+ if (force_nonblock && !req->open.ignore_nonblock)
return -EAGAIN;
ret = build_open_flags(&req->open.how, &op);
@@ -3853,6 +3855,21 @@
if (IS_ERR(file)) {
put_unused_fd(ret);
ret = PTR_ERR(file);
+ /*
+ * A work-around to ensure that /proc/self works that way
+ * that it should - if we get -EOPNOTSUPP back, then assume
+ * that proc_self_get_link() failed us because we're in async
+ * context. We should be safe to retry this from the task
+ * itself with force_nonblock == false set, as it should not
+ * block on lookup. Would be nice to know this upfront and
+ * avoid the async dance, but doesn't seem feasible.
+ */
+ if (ret == -EOPNOTSUPP && io_wq_current_is_worker()) {
+ req->open.ignore_nonblock = true;
+ refcount_inc(&req->refs);
+ io_req_task_queue(req);
+ return 0;
+ }
} else {
fsnotify_open(file);
fd_install(ret, file);
@@ -6957,9 +6974,7 @@
return -ENXIO;
spin_lock(&data->lock);
- if (!list_empty(&data->ref_list))
- ref_node = list_first_entry(&data->ref_list,
- struct fixed_file_ref_node, node);
+ ref_node = data->node;
spin_unlock(&data->lock);
if (ref_node)
percpu_ref_kill(&ref_node->refs);
@@ -7308,10 +7323,6 @@
kfree(pfile);
}
- spin_lock(&file_data->lock);
- list_del(&ref_node->node);
- spin_unlock(&file_data->lock);
-
percpu_ref_exit(&ref_node->refs);
kfree(ref_node);
percpu_ref_put(&file_data->refs);
@@ -7338,17 +7349,32 @@
static void io_file_data_ref_zero(struct percpu_ref *ref)
{
struct fixed_file_ref_node *ref_node;
+ struct fixed_file_data *data;
struct io_ring_ctx *ctx;
- bool first_add;
+ bool first_add = false;
int delay = HZ;
ref_node = container_of(ref, struct fixed_file_ref_node, refs);
- ctx = ref_node->file_data->ctx;
+ data = ref_node->file_data;
+ ctx = data->ctx;
- if (percpu_ref_is_dying(&ctx->file_data->refs))
+ spin_lock(&data->lock);
+ ref_node->done = true;
+
+ while (!list_empty(&data->ref_list)) {
+ ref_node = list_first_entry(&data->ref_list,
+ struct fixed_file_ref_node, node);
+ /* recycle ref nodes in order */
+ if (!ref_node->done)
+ break;
+ list_del(&ref_node->node);
+ first_add |= llist_add(&ref_node->llist, &ctx->file_put_llist);
+ }
+ spin_unlock(&data->lock);
+
+ if (percpu_ref_is_dying(&data->refs))
delay = 0;
- first_add = llist_add(&ref_node->llist, &ctx->file_put_llist);
if (!delay)
mod_delayed_work(system_wq, &ctx->file_put_work, 0);
else if (first_add)
@@ -7372,6 +7398,7 @@
INIT_LIST_HEAD(&ref_node->node);
INIT_LIST_HEAD(&ref_node->file_list);
ref_node->file_data = ctx->file_data;
+ ref_node->done = false;
return ref_node;
}
@@ -7467,7 +7494,7 @@
file_data->node = ref_node;
spin_lock(&file_data->lock);
- list_add(&ref_node->node, &file_data->ref_list);
+ list_add_tail(&ref_node->node, &file_data->ref_list);
spin_unlock(&file_data->lock);
percpu_ref_get(&file_data->refs);
return ret;
@@ -7626,7 +7653,7 @@
if (needs_switch) {
percpu_ref_kill(&data->node->refs);
spin_lock(&data->lock);
- list_add(&ref_node->node, &data->ref_list);
+ list_add_tail(&ref_node->node, &data->ref_list);
data->node = ref_node;
spin_unlock(&data->lock);
percpu_ref_get(&ctx->file_data->refs);
diff --git a/fs/proc/self.c b/fs/proc/self.c
index 72cd69b..cc71ce3 100644
--- a/fs/proc/self.c
+++ b/fs/proc/self.c
@@ -16,6 +16,13 @@
pid_t tgid = task_tgid_nr_ns(current, ns);
char *name;
+ /*
+ * Not currently supported. Once we can inherit all of struct pid,
+ * we can allow this.
+ */
+ if (current->flags & PF_KTHREAD)
+ return ERR_PTR(-EOPNOTSUPP);
+
if (!tgid)
return ERR_PTR(-ENOENT);
/* max length of unsigned int in decimal + NULL term */
diff --git a/mm/filemap.c b/mm/filemap.c
index d5e7c20..3ebbe64 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2347,10 +2347,15 @@
page_not_up_to_date:
/* Get exclusive access to the page ... */
- if (iocb->ki_flags & IOCB_WAITQ)
+ if (iocb->ki_flags & IOCB_WAITQ) {
+ if (written) {
+ put_page(page);
+ goto out;
+ }
error = lock_page_async(page, iocb->ki_waitq);
- else
+ } else {
error = lock_page_killable(page);
+ }
if (unlikely(error))
goto readpage_error;
@@ -2393,10 +2398,15 @@
}
if (!PageUptodate(page)) {
- if (iocb->ki_flags & IOCB_WAITQ)
+ if (iocb->ki_flags & IOCB_WAITQ) {
+ if (written) {
+ put_page(page);
+ goto out;
+ }
error = lock_page_async(page, iocb->ki_waitq);
- else
+ } else {
error = lock_page_killable(page);
+ }
if (unlikely(error))
goto readpage_error;
