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| author | Pavel Begunkov <asml.silence@gmail.com> | 2022-06-25 13:55:38 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-07-25 03:39:16 +0300 |
| commit | 6e73dffbb93cb8797cd4e42e98d837edf0f1a967 (patch) | |
| tree | a1ea7810d2221f23c3bc0f673e6cc6a23262b5c7 /io_uring/filetable.c | |
| parent | e6130eba8a848a7a6ba6c534bd8f6d60749ae1a9 (diff) | |
| download | linux-6e73dffbb93cb8797cd4e42e98d837edf0f1a967.tar.xz | |
io_uring: let to set a range for file slot allocation
From recently io_uring provides an option to allocate a file index for
operation registering fixed files. However, it's utterly unusable with
mixed approaches when for a part of files the userspace knows better
where to place it, as it may race and users don't have any sane way to
pick a slot and hoping it will not be taken.
Let the userspace to register a range of fixed file slots in which the
auto-allocation happens. The use case is splittting the fixed table in
two parts, where on of them is used for auto-allocation and another for
slot-specified operations.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/66ab0394e436f38437cf7c44676e1920d09687ad.1656154403.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring/filetable.c')
| -rw-r--r-- | io_uring/filetable.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/io_uring/filetable.c b/io_uring/filetable.c index abaa5ba7f655..7b473259f3f4 100644 --- a/io_uring/filetable.c +++ b/io_uring/filetable.c @@ -16,7 +16,7 @@ static int io_file_bitmap_get(struct io_ring_ctx *ctx) { struct io_file_table *table = &ctx->file_table; - unsigned long nr = ctx->nr_user_files; + unsigned long nr = ctx->file_alloc_end; int ret; do { @@ -24,11 +24,10 @@ static int io_file_bitmap_get(struct io_ring_ctx *ctx) if (ret != nr) return ret; - if (!table->alloc_hint) + if (table->alloc_hint == ctx->file_alloc_start) break; - nr = table->alloc_hint; - table->alloc_hint = 0; + table->alloc_hint = ctx->file_alloc_start; } while (1); return -ENFILE; @@ -175,3 +174,20 @@ int io_fixed_fd_remove(struct io_ring_ctx *ctx, unsigned int offset) io_rsrc_node_switch(ctx, ctx->file_data); return 0; } + +int io_register_file_alloc_range(struct io_ring_ctx *ctx, + struct io_uring_file_index_range __user *arg) +{ + struct io_uring_file_index_range range; + u32 end; + + if (copy_from_user(&range, arg, sizeof(range))) + return -EFAULT; + if (check_add_overflow(range.off, range.len, &end)) + return -EOVERFLOW; + if (range.resv || end > ctx->nr_user_files) + return -EINVAL; + + io_file_table_set_alloc_range(ctx, range.off, range.len); + return 0; +} |