- 29 5月, 2018 1 次提交
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由 Christoph Hellwig 提交于
Looks like this got lost in a merge. Signed-off-by: NChristoph Hellwig <hch@lst.de> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 26 5月, 2018 33 次提交
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由 Christoph Hellwig 提交于
The big change is that random_read_wait and random_write_wait are merged into a single waitqueue that uses keyed wakeups. Because wait_event_* doesn't know about that this will lead to occassional spurious wakeups in _random_read and add_hwgenerator_randomness, but wait_event_* is designed to handle these and were are not in a a hot path there. Signed-off-by: NChristoph Hellwig <hch@lst.de> Acked-by: NTheodore Ts'o <tytso@mit.edu> Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Now that sock_poll handles a NULL ->poll or ->poll_mask there is no need for a stub. Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
The socket file operations still implement ->poll until all protocols are switched over. Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Factor out two busy poll related helpers for late reuse, and remove a command that isn't very helpful, especially with the __poll_t annotations in place. Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
If we can acquire ctx_lock without spinning we can just remove our iocb from the active_reqs list, and thus complete the iocbs from the wakeup context. Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
Simple one-shot poll through the io_submit() interface. To poll for a file descriptor the application should submit an iocb of type IOCB_CMD_POLL. It will poll the fd for the events specified in the the first 32 bits of the aio_buf field of the iocb. Unlike poll or epoll without EPOLLONESHOT this interface always works in one shot mode, that is once the iocb is completed, it will have to be resubmitted. Signed-off-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
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由 Christoph Hellwig 提交于
With the current aio code there is no need for the magic KIOCB_CANCELLED value, as a cancelation just kicks the driver to queue the completion ASAP, with all actual completion handling done in another thread. Given that both the completion path and cancelation take the context lock there is no need for magic cmpxchg loops either. If we remove iocbs from the active list after calling ->ki_cancel (but with ctx_lock still held), we can also rely on the invariant thay anything found on the list has a ->ki_cancel callback and can be cancelled, further simplifing the code. Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
No need to pass the key field to lookup_iocb to compare it with KIOCB_KEY, as we can do that right after retrieving it from userspace. Also move the KIOCB_KEY definition to aio.c as it is an internal value not used by any other place in the kernel. Signed-off-by: NChristoph Hellwig <hch@lst.de>
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由 Christoph Hellwig 提交于
->get_poll_head returns the waitqueue that the poll operation is going to sleep on. Note that this means we can only use a single waitqueue for the poll, unlike some current drivers that use two waitqueues for different events. But now that we have keyed wakeups and heavily use those for poll there aren't that many good reason left to keep the multiple waitqueues, and if there are any ->poll is still around, the driver just won't support aio poll. Signed-off-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
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由 Christoph Hellwig 提交于
These abstract out calls to the poll method in preparation for changes in how we poll. Signed-off-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com> Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Christoph Hellwig 提交于
Use straightline code with failure handling gotos instead of a lot of nested conditionals. Signed-off-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
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由 Christoph Hellwig 提交于
No users outside of select.c. Signed-off-by: NChristoph Hellwig <hch@lst.de> Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
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由 Christoph Hellwig 提交于
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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- 24 5月, 2018 1 次提交
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由 Al Viro 提交于
If io_destroy() gets to cancelling everything that can be cancelled and gets to kiocb_cancel() calling the function driver has left in ->ki_cancel, it becomes vulnerable to a race with IO completion. At that point req is already taken off the list and aio_complete() does *NOT* spin until we (in free_ioctx_users()) releases ->ctx_lock. As the result, it proceeds to kiocb_free(), freing req just it gets passed to ->ki_cancel(). Fix is simple - remove from the list after the call of kiocb_cancel(). All instances of ->ki_cancel() already have to cope with the being called with iocb still on list - that's what happens in io_cancel(2). Cc: stable@kernel.org Fixes: 0460fef2 "aio: use cancellation list lazily" Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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- 22 5月, 2018 5 次提交
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由 Al Viro 提交于
kill_ioctx() used to have an explicit RCU delay between removing the reference from ->ioctx_table and percpu_ref_kill() dropping the refcount. At some point that delay had been removed, on the theory that percpu_ref_kill() itself contained an RCU delay. Unfortunately, that was the wrong kind of RCU delay and it didn't care about rcu_read_lock() used by lookup_ioctx(). As the result, we could get ctx freed right under lookup_ioctx(). Tejun has fixed that in a6d7cff4 ("fs/aio: Add explicit RCU grace period when freeing kioctx"); however, that fix is not enough. Suppose io_destroy() from one thread races with e.g. io_setup() from another; CPU1 removes the reference from current->mm->ioctx_table[...] just as CPU2 has picked it (under rcu_read_lock()). Then CPU1 proceeds to drop the refcount, getting it to 0 and triggering a call of free_ioctx_users(), which proceeds to drop the secondary refcount and once that reaches zero calls free_ioctx_reqs(). That does INIT_RCU_WORK(&ctx->free_rwork, free_ioctx); queue_rcu_work(system_wq, &ctx->free_rwork); and schedules freeing the whole thing after RCU delay. In the meanwhile CPU2 has gotten around to percpu_ref_get(), bumping the refcount from 0 to 1 and returned the reference to io_setup(). Tejun's fix (that queue_rcu_work() in there) guarantees that ctx won't get freed until after percpu_ref_get(). Sure, we'd increment the counter before ctx can be freed. Now we are out of rcu_read_lock() and there's nothing to stop freeing of the whole thing. Unfortunately, CPU2 assumes that since it has grabbed the reference, ctx is *NOT* going away until it gets around to dropping that reference. The fix is obvious - use percpu_ref_tryget_live() and treat failure as miss. It's not costlier than what we currently do in normal case, it's safe to call since freeing *is* delayed and it closes the race window - either lookup_ioctx() comes before percpu_ref_kill() (in which case ctx->users won't reach 0 until the caller of lookup_ioctx() drops it) or lookup_ioctx() fails, ctx->users is unaffected and caller of lookup_ioctx() doesn't see the object in question at all. Cc: stable@kernel.org Fixes: a6d7cff4 "fs/aio: Add explicit RCU grace period when freeing kioctx" Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
open file, unlink it, then use ioctl(2) to make it immutable or append only. Now close it and watch the blocks *not* freed... Immutable/append-only checks belong in ->setattr(). Note: the bug is old and backport to anything prior to 737f2e93 ("ext2: convert to use the new truncate convention") will need these checks lifted into ext2_setattr(). Cc: stable@kernel.org Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
That can (and does, on some filesystems) happen - ->mkdir() (and thus vfs_mkdir()) can legitimately leave its argument negative and just unhash it, counting upon the lookup to pick the object we'd created next time we try to look at that name. Some vfs_mkdir() callers forget about that possibility... Acked-by: NJ. Bruce Fields <bfields@redhat.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
That can (and does, on some filesystems) happen - ->mkdir() (and thus vfs_mkdir()) can legitimately leave its argument negative and just unhash it, counting upon the lookup to pick the object we'd created next time we try to look at that name. Some vfs_mkdir() callers forget about that possibility... Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Al Viro 提交于
new_sb is left uninitialized in case of early failures in kernfs_mount_ns(), and while IS_ERR(root) is true in all such cases, using IS_ERR(root) || !new_sb is not a solution - IS_ERR(root) is true in some cases when new_sb is true. Make sure new_sb is initialized (and matches the reality) in all cases and fix the condition for dropping kobj reference - we want it done precisely in those situations where the reference has not been transferred into a new super_block instance. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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