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2023-11-15io_uring/fdinfo: remove need for sqpoll lock for thread/pid retrievalJens Axboe
A previous commit added a trylock for getting the SQPOLL thread info via fdinfo, but this introduced a regression where we often fail to get it if the thread is busy. For that case, we end up not printing the current CPU and PID info. Rather than rely on this lock, just print the pid we already stored in the io_sq_data struct, and ensure we update the current CPU every time we've slept or potentially rescheduled. The latter won't potentially be 100% accurate, but that wasn't the case before either as the task can get migrated at any time unless it has been pinned at creation time. We retain keeping the io_sq_data dereference inside the ctx->uring_lock, as it has always been, as destruction of the thread and data happen below that. We could make this RCU safe, but there's little point in doing that. With this, we always print the last valid information we had, rather than have spurious outputs with missing information. Fixes: 7644b1a1c9a7 ("io_uring/fdinfo: lock SQ thread while retrieving thread cpu/pid") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-10-25io_uring/fdinfo: lock SQ thread while retrieving thread cpu/pidJens Axboe
We could race with SQ thread exit, and if we do, we'll hit a NULL pointer dereference when the thread is cleared. Grab the SQPOLL data lock before attempting to get the task cpu and pid for fdinfo, this ensures we have a stable view of it. Cc: stable@vger.kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=218032 Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-09-01io_uring/fdinfo: only print ->sq_array[] if it's thereJens Axboe
If a ring is setup with IORING_SETUP_NO_SQARRAY, then we don't have the SQ array. Don't try to dump info from it through fdinfo if that is the case. Reported-by: syzbot+216e2ea6e0bf4a0acdd7@syzkaller.appspotmail.com Fixes: 2af89abda7d9 ("io_uring: add option to remove SQ indirection") Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-08-10io_uring/fdinfo: get rid of ref trygetJens Axboe
The caller holds a reference to the ring itself, so by definition the ring cannot go away. There's no need to play games with tryget for the reference, as we don't need an extra reference at all. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2023-03-01capability: just use a 'u64' instead of a 'u32[2]' arrayLinus Torvalds
Back in 2008 we extended the capability bits from 32 to 64, and we did it by extending the single 32-bit capability word from one word to an array of two words. It was then obfuscated by hiding the "2" behind two macro expansions, with the reasoning being that maybe it gets extended further some day. That reasoning may have been valid at the time, but the last thing we want to do is to extend the capability set any more. And the array of values not only causes source code oddities (with loops to deal with it), but also results in worse code generation. It's a lose-lose situation. So just change the 'u32[2]' into a 'u64' and be done with it. We still have to deal with the fact that the user space interface is designed around an array of these 32-bit values, but that was the case before too, since the array layouts were different (ie user space doesn't use an array of 32-bit values for individual capability masks, but an array of 32-bit slices of multiple masks). So that marshalling of data is actually simplified too, even if it does remain somewhat obscure and odd. This was all triggered by my reaction to the new "cap_isidentical()" introduced recently. By just using a saner data structure, it went from unsigned __capi; CAP_FOR_EACH_U32(__capi) { if (a.cap[__capi] != b.cap[__capi]) return false; } return true; to just being return a.val == b.val; instead. Which is rather more obvious both to humans and to compilers. Cc: Mateusz Guzik <mjguzik@gmail.com> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: Serge Hallyn <serge@hallyn.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Paul Moore <paul@paul-moore.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-01-10io_uring/fdinfo: include locked hash table in fdinfo outputJens Axboe
A previous commit split the hash table for polled requests into two parts, but didn't get the fdinfo output updated. This means that it's less useful for debugging, as we may think a given request is not pending poll. Fix this up by dumping the locked hash table contents too. Fixes: 9ca9fb24d5fe ("io_uring: mutex locked poll hashing") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-10-12io_uring: fix fdinfo sqe offsets calculationPavel Begunkov
Only with the big sqe feature they take 128 bytes per entry, but we unconditionally advance by 128B. Fix it by using sq_shift. Fixes: 3b8fdd1dc35e3 ("io_uring/fdinfo: fix sqe dumping for IORING_SETUP_SQE128") Reported-and-tested-by: syzbot+e5198737e8a2d23d958c@syzkaller.appspotmail.com Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/8b41287cb75d5efb8fcb5cccde845ddbbadd8372.1665449983.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21io_uring/fdinfo: fix sqe dumping for IORING_SETUP_SQE128Jens Axboe
If we have doubly sized SQEs, then we need to shift the sq index by 1 to account for using two entries for a single request. The CQE dumping gets this right, but the SQE one does not. Improve the SQE dumping in general, the information dumped is pretty sparse and doesn't even cover the whole basic part of the SQE. Include information on the extended part of the SQE, if doubly sized SQEs are in use. A typical dump now looks like the following: [...] SQEs: 32 32: opcode:URING_CMD, fd:0, flags:1, off:3225964160, addr:0x0, rw_flags:0x0, buf_index:0 user_data:2721, e0:0x0, e1:0xffffb8041000, e2:0x100000000000, e3:0x5500, e4:0x7, e5:0x0, e6:0x0, e7:0x0 33: opcode:URING_CMD, fd:0, flags:1, off:3225964160, addr:0x0, rw_flags:0x0, buf_index:0 user_data:2722, e0:0x0, e1:0xffffb8043000, e2:0x100000000000, e3:0x5508, e4:0x7, e5:0x0, e6:0x0, e7:0x0 34: opcode:URING_CMD, fd:0, flags:1, off:3225964160, addr:0x0, rw_flags:0x0, buf_index:0 user_data:2723, e0:0x0, e1:0xffffb8045000, e2:0x100000000000, e3:0x5510, e4:0x7, e5:0x0, e6:0x0, e7:0x0 [...] Fixes: ebdeb7c01d02 ("io_uring: add support for 128-byte SQEs") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-21io_uring/fdinfo: get rid of unnecessary is_cqe32 variableJens Axboe
We already have the cq_shift, just use that to tell if we have doubly sized CQEs or not. While in there, cleanup the CQE32 vs normal CQE size printing. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: move a few private types to local headersJens Axboe
Commit 3a3d47fa9cfd ("io_uring: make io_uring_types.h public") moved a bunch of io_uring types to a kernel wide header, so we could make tracing a bit saner rather than pass in a ton of arguments. However, there are a few types in there that are not really needed to be system wide. Move the cancel data and mapped buffers back to the appropriate io_uring local headers. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: kill extra io_uring_types.h includesPavel Begunkov
io_uring/io_uring.h already includes io_uring_types.h, no need to include it every time. Kill it in a bunch of places, it prepares us for following patches. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/94d8c943fbe0ef949981c508ddcee7fc1c18850f.1655384063.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: introduce a struct for hash tablePavel Begunkov
Instead of passing around a pointer to hash buckets, add a bit of type safety and wrap it into a structure. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/d65bc3faba537ec2aca9eabf334394936d44bd28.1655371007.git.asml.silence@gmail.com Reviewed-by: Hao Xu <howeyxu@tencent.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: switch cancel_hash to use per entry spinlockHao Xu
Add a new io_hash_bucket structure so that each bucket in cancel_hash has separate spinlock. Use per entry lock for cancel_hash, this removes some completion lock invocation and remove contension between different cancel_hash entries. Signed-off-by: Hao Xu <howeyxu@tencent.com> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/05d1e135b0c8bce9d1441e6346776589e5783e26.1655371007.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24io_uring: move fdinfo helpers to its own fileJens Axboe
This also means moving a bit more of the fixed file handling to the filetable side, which makes sense separately too. Signed-off-by: Jens Axboe <axboe@kernel.dk>