[Devel] [PATCH rh7] fs/aio: show real number of aio events in fs.aio-nr sysctl

[Andrey Ryabinin]

fs.aio-nr accounts number of aio events requested by user via io_setup()
syscall. The kernel usually creates more events than was requested.
CRIU doesn't care about the number of requested events, it cares only
about created events. So while restoring the process CRIU requests
in io_setup() the number of actually created events. This leads
to inconsistent value of fs.aio-nr after the restore.

Let's account in fs.aio-nr a number of created events, not requested.

https://jira.sw.ru/browse/PSBM-47209

Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
 fs/aio.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index 29d02ab..19ebcd1 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -633,12 +633,12 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
 
 	/* limit the number of system wide aios */
 	spin_lock(&ve->aio_nr_lock);
-	if (ve->aio_nr + nr_events > ve->aio_max_nr ||
-	    ve->aio_nr + nr_events < ve->aio_nr) {
+	if (ve->aio_nr + ctx->nr_events > ve->aio_max_nr ||
+	    ve->aio_nr + ctx->nr_events < ve->aio_nr) {
 		spin_unlock(&ve->aio_nr_lock);
 		goto out_cleanup;
 	}
-	ve->aio_nr += ctx->max_reqs;
+	ve->aio_nr += ctx->nr_events;
 	spin_unlock(&ve->aio_nr_lock);
 
 	/* now link into global list. */
-- 
2.7.3