Commit 79d5ca5617cfc9be13a4f314ed800fca1267d903
Committed by
Anthony Liguori
Anthony Liguori
1 parent
d6ecb036
AIO deletion race fix
When deleting an fd event there is a chance the object doesn't get deleted, but only ->deleted set positive and deleted somewhere later. Now, if we create a handler for the fd again before the actual deletion occurs, we end up writing data into an object that has ->deleted set, which is obviously wrong. I see two ways to fix this: 1. Don't return ->deleted objects in the search 2. Unset ->deleted in the search This patch implements 1. which feels safer to do. It fixes AIO issues I've seen with curl, as libcurl unsets fd event listeners pretty frequently. Signed-off-by: Alexander Graf <alex@csgraf.de> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
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aio.c
| @@ -44,7 +44,8 @@ static AioHandler *find_aio_handler(int fd) | @@ -44,7 +44,8 @@ static AioHandler *find_aio_handler(int fd) | ||
| 44 | 44 | ||
| 45 | LIST_FOREACH(node, &aio_handlers, node) { | 45 | LIST_FOREACH(node, &aio_handlers, node) { |
| 46 | if (node->fd == fd) | 46 | if (node->fd == fd) |
| 47 | - return node; | 47 | + if (!node->deleted) |
| 48 | + return node; | ||
| 48 | } | 49 | } |
| 49 | 50 | ||
| 50 | return NULL; | 51 | return NULL; |