| Paolo Valente | 70f2871 | 2013-05-09 19:10:02 +0200 | [diff] [blame] | 1 | /* |
| 2 | * BFQ: I/O context handling. |
| 3 | * |
| 4 | * Based on ideas and code from CFQ: |
| 5 | * Copyright (C) 2003 Jens Axboe <axboe@kernel.dk> |
| 6 | * |
| 7 | * Copyright (C) 2008 Fabio Checconi <fabio@gandalf.sssup.it> |
| 8 | * Paolo Valente <paolo.valente@unimore.it> |
| 9 | * |
| 10 | * Copyright (C) 2010 Paolo Valente <paolo.valente@unimore.it> |
| 11 | */ |
| 12 | |
| 13 | /** |
| 14 | * icq_to_bic - convert iocontext queue structure to bfq_io_cq. |
| 15 | * @icq: the iocontext queue. |
| 16 | */ |
| 17 | static inline struct bfq_io_cq *icq_to_bic(struct io_cq *icq) |
| 18 | { |
| 19 | /* bic->icq is the first member, %NULL will convert to %NULL */ |
| 20 | return container_of(icq, struct bfq_io_cq, icq); |
| 21 | } |
| 22 | |
| 23 | /** |
| 24 | * bfq_bic_lookup - search into @ioc a bic associated to @bfqd. |
| 25 | * @bfqd: the lookup key. |
| 26 | * @ioc: the io_context of the process doing I/O. |
| 27 | * |
| 28 | * Queue lock must be held. |
| 29 | */ |
| 30 | static inline struct bfq_io_cq *bfq_bic_lookup(struct bfq_data *bfqd, |
| 31 | struct io_context *ioc) |
| 32 | { |
| 33 | if (ioc) |
| 34 | return icq_to_bic(ioc_lookup_icq(ioc, bfqd->queue)); |
| 35 | return NULL; |
| 36 | } |