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| author | Jens Axboe <axboe@kernel.dk> | 2022-05-07 14:20:40 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-05-13 06:28:40 -0600 |
| commit | b70b8e3331d8134ab993368a6e0eb18c1acb1b1d (patch) | |
| tree | 80e856b9353720c33624fbcaa09ab1143d4e21d3 /fs | |
| parent | d78bd8adfcbc55b9dc01e9034a55b2a61a2124dc (diff) | |
| download | linux-b70b8e3331d8134ab993368a6e0eb18c1acb1b1d.tar.bz2 | |
io_uring: add basic fixed file allocator
Applications currently always pick where they want fixed files to go.
In preparation for allowing these types of commands with multishot
support, add a basic allocator in the fixed file table.
Reviewed-by: Hao Xu <howeyxu@tencent.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/io_uring.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index f8a685cc0363..8c40411a7e78 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -258,6 +258,7 @@ struct io_rsrc_put { struct io_file_table { struct io_fixed_file *files; unsigned long *bitmap; + unsigned int alloc_hint; }; struct io_rsrc_node { @@ -4696,6 +4697,31 @@ static int io_openat2_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) return __io_openat_prep(req, sqe); } +static int __maybe_unused io_file_bitmap_get(struct io_ring_ctx *ctx) +{ + struct io_file_table *table = &ctx->file_table; + unsigned long nr = ctx->nr_user_files; + int ret; + + if (table->alloc_hint >= nr) + table->alloc_hint = 0; + + do { + ret = find_next_zero_bit(table->bitmap, nr, table->alloc_hint); + if (ret != nr) { + table->alloc_hint = ret + 1; + return ret; + } + if (!table->alloc_hint) + break; + + nr = table->alloc_hint; + table->alloc_hint = 0; + } while (1); + + return -ENFILE; +} + static int io_openat2(struct io_kiocb *req, unsigned int issue_flags) { struct open_flags op; @@ -8664,11 +8690,14 @@ static inline void io_file_bitmap_set(struct io_file_table *table, int bit) { WARN_ON_ONCE(test_bit(bit, table->bitmap)); __set_bit(bit, table->bitmap); + if (bit == table->alloc_hint) + table->alloc_hint++; } static inline void io_file_bitmap_clear(struct io_file_table *table, int bit) { __clear_bit(bit, table->bitmap); + table->alloc_hint = bit; } static void __io_sqe_files_unregister(struct io_ring_ctx *ctx) |