linux/include/net/9p, branch v4.20

9p: Add refcount to p9_req_t

2018-09-07T16:39:47Z

To avoid use-after-free(s), use a refcount to keep track of the usable references to any instantiated struct p9_req_t. This commit adds p9_req_put(), p9_req_get() and p9_req_try_get() as wrappers to kref_put(), kref_get() and kref_get_unless_zero(). These are used by the client and the transports to keep track of valid requests' references. p9_free_req() is added back and used as callback by kref_put(). Add SLAB_TYPESAFE_BY_RCU as it ensures that the memory freed by kmem_cache_free() will not be reused for another type until the rcu synchronisation period is over, so an address gotten under rcu read lock is safe to inc_ref() without corrupting random memory while the lock is held. Link: http://lkml.kernel.org/r/1535626341-20693-1-git-send-email-asmadeus@codewreck.org Co-developed-by: Dominique Martinet Signed-off-by: Tomas Bortoli Reported-by: syzbot+467050c1ce275af2a5b8@syzkaller.appspotmail.com Signed-off-by: Dominique Martinet

9p: add a per-client fcall kmem_cache

2018-09-07T16:39:47Z

Having a specific cache for the fcall allocations helps speed up end-to-end latency. The caches will automatically be merged if there are multiple caches of items with the same size so we do not need to try to share a cache between different clients of the same size. Since the msize is negotiated with the server, only allocate the cache after that negotiation has happened - previous allocations or allocations of different sizes (e.g. zero-copy fcall) are made with kmalloc directly. Some figures on two beefy VMs with Connect-IB (sriov) / trans=rdma, with ior running 32 processes in parallel doing small 32 bytes IOs: - no alloc (4.18-rc7 request cache): 65.4k req/s - non-power of two alloc, no patch: 61.6k req/s - power of two alloc, no patch: 62.2k req/s - non-power of two alloc, with patch: 64.7k req/s - power of two alloc, with patch: 65.1k req/s Link: http://lkml.kernel.org/r/1532943263-24378-2-git-send-email-asmadeus@codewreck.org Signed-off-by: Dominique Martinet Acked-by: Jun Piao Cc: Matthew Wilcox Cc: Greg Kurz

9p: embed fcall in req to round down buffer allocs

2018-09-07T16:39:45Z

'msize' is often a power of two, or at least page-aligned, so avoiding an overhead of two dozen bytes for each allocation will help the allocator do its work and reduce memory fragmentation. Link: http://lkml.kernel.org/r/1533825236-22896-1-git-send-email-asmadeus@codewreck.org Suggested-by: Matthew Wilcox Signed-off-by: Dominique Martinet Reviewed-by: Greg Kurz Acked-by: Jun Piao Cc: Matthew Wilcox

9p: Remove p9_idpool

2018-08-29T04:39:57Z

There are no more users left of the p9_idpool; delete it. Link: http://lkml.kernel.org/r/20180711210225.19730-7-willy@infradead.org Signed-off-by: Matthew Wilcox Cc: Eric Van Hensbergen Cc: Ron Minnich Cc: Latchesar Ionkov Signed-off-by: Dominique Martinet

9p: Use a slab for allocating requests

2018-08-29T04:39:57Z

Replace the custom batch allocation with a slab. Use an IDR to store pointers to the active requests instead of an array. We don't try to handle P9_NOTAG specially; the IDR will happily shrink all the way back once the TVERSION call has completed. Link: http://lkml.kernel.org/r/20180711210225.19730-6-willy@infradead.org Signed-off-by: Matthew Wilcox Cc: Eric Van Hensbergen Cc: Ron Minnich Cc: Latchesar Ionkov Signed-off-by: Dominique Martinet

9p: Embed wait_queue_head into p9_req_t

2018-08-13T00:21:44Z

On a 64-bit system, the wait_queue_head_t is 24 bytes while the pointer to it is 8 bytes. Growing the p9_req_t by 16 bytes is better than performing a 24-byte memory allocation. Link: http://lkml.kernel.org/r/20180711210225.19730-5-willy@infradead.org Signed-off-by: Matthew Wilcox Reviewed-by: Greg Kurz Cc: Eric Van Hensbergen Cc: Ron Minnich Cc: Latchesar Ionkov Signed-off-by: Dominique Martinet

9p: Replace the fidlist with an IDR

2018-08-13T00:21:44Z

The p9_idpool being used to allocate the IDs uses an IDR to allocate the IDs ... which we then keep in a doubly-linked list, rather than in the IDR which allocated them. We can use an IDR directly which saves two pointers per p9_fid, and a tiny memory allocation per p9_client. Link: http://lkml.kernel.org/r/20180711210225.19730-4-willy@infradead.org Signed-off-by: Matthew Wilcox Cc: Eric Van Hensbergen Cc: Ron Minnich Cc: Latchesar Ionkov Signed-off-by: Dominique Martinet

9p: Implement show_options

2017-07-11T10:08:58Z

Implement the show_options superblock op for 9p as part of a bid to get rid of s_options and generic_show_options() to make it easier to implement a context-based mount where the mount options can be passed individually over a file descriptor. Signed-off-by: David Howells cc: Eric Van Hensbergen cc: Ron Minnich cc: Latchesar Ionkov cc: v9fs-developer@lists.sourceforge.net Signed-off-by: Al Viro

9p: constify ->d_name handling

2017-01-12T09:01:17Z

Signed-off-by: Al Viro

9p: switch p9_client_read() to passing struct iov_iter *

2015-04-12T02:28:27Z

... and make it loop Signed-off-by: Al Viro