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Subject[PATCH 1/3] aio_ring_remap: turn the ctx->dead check into WARN_ON()
atomic_read(&ctx->dead) in aio_ring_remap() looks confusing.
kill_ioctx() sets ctx->dead and removes ctx from ->ioctx_table
"atomically" under mm->ioctx_lock, so aio_ring_remap() can never
see a dead ctx.

If we really want this check, we should put it under WARN_ON()
and it should not depend on aio_ring_file == file.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
fs/aio.c | 16 ++++++++--------
1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index 480440f..0693333 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -325,14 +325,14 @@ static int aio_ring_remap(struct file *file, struct vm_area_struct *vma)
rcu_read_lock();
table = rcu_dereference(mm->ioctx_table);
for (i = 0; i < table->nr; i++) {
- struct kioctx *ctx;
-
- ctx = table->table[i];
- if (ctx && ctx->aio_ring_file == file) {
- if (!atomic_read(&ctx->dead)) {
- ctx->user_id = ctx->mmap_base = vma->vm_start;
- res = 0;
- }
+ struct kioctx *ctx = table->table[i];
+
+ if (!ctx || WARN_ON(atomic_read(&ctx->dead)))
+ continue;
+
+ if (ctx->aio_ring_file == file) {
+ ctx->user_id = ctx->mmap_base = vma->vm_start;
+ res = 0;
break;
}
}
--
1.5.5.1


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