kernel/git/stable/linux.git/io_uring/rsrc.h, branch linux-7.2.y

io_uring/rsrc: bump struct io_mapped_ubuf length field to size_t

2026-05-14T14:12:23+00:00

In preparation for supporting bigger individual buffers, bump the length field to a full 8-bytes with size_t rather than an unsigned int. Signed-off-by: Jens Axboe

io_uring/rsrc: add huge page accounting for registered buffers

2026-05-14T14:11:53+00:00

Track huge page references in a per-ring xarray to prevent double accounting when the same huge page is used by multiple registered buffers, either within the same ring or across cloned rings. When registering buffers backed by huge pages, we need to account for RLIMIT_MEMLOCK. But if multiple buffers share the same huge page (common with cloned buffers), we must not account for the same page multiple times. Similarly, we must only unaccount when the last reference to a huge page is released. Maintain a per-ring xarray (hpage_acct) that tracks reference counts for each huge page. When registering a buffer, for each unique huge page, increment its accounting reference count, and only account pages that are newly added. When unregistering a buffer, for each unique huge page, decrement its refcount. Once the refcount hits zero, the page is unaccounted. Note: any account is done against the ctx->user that was assigned when the ring was setup. As before, if root is running the operation, no accounting is done. With these changes, any use of imu->acct_pages is also dead, hence kill it from struct io_mapped_ubuf. This shrinks it from 56b to 48b on a 64-bit arch. Additionally, hpage_already_acct() is gone, which was an O(M*M) scan over current + previous registrations. Signed-off-by: Jens Axboe

io_uring/rsrc: unify nospec indexing for direct descriptors

2026-04-21T18:18:54+00:00

For file updates, the node reset isn't capping the value via array_index_nospec() like the other paths do. Ensure it's all sane and have the update path do the proper capping as well. Reviewed-by: Gabriel Krisman Bertazi Signed-off-by: Jens Axboe

io_uring/rsrc: replace reg buffer bit field with flags

2026-02-10T12:26:15+00:00

I'll need a flag in the registered buffer struct for dmabuf work, and it'll be more convenient to have a flags field rather than bit fields, especially for io_mapped_ubuf initialisation. We might want to add more flags in the future as well. For example, it might be useful for debugging and potentially optimisations to split out a flag indicating the shape of the buffer to gate iov_iter_advance() walks vs bit/mask arithmetics. It can also be combined with the direction mask field. Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe

io_uring/rsrc: take unsigned index in io_rsrc_node_lookup()

2026-01-22T22:58:17+00:00

io_rsrc_node_lookup() takes a signed int index as input and compares it to an unsigned length. Since the signed int is implicitly cast to an unsigned int for the comparison and the length is bounded by IORING_MAX_FIXED_FILES/IORING_MAX_REG_BUFFERS, negative indices are already rejected on architectures where int is at least 32 bits. Make this a bit clearer and avoid compiler warnings for comparisons of signed and unsigned values by taking an unsigned int index instead. Signed-off-by: Caleb Sander Mateos Signed-off-by: Jens Axboe

io_uring/rsrc: refactor io_{un}account_mem() to take {user,mm}_struct param

2025-11-06T23:23:21+00:00

Refactor io_{un}account_mem() to take user_struct and mm_struct directly, instead of accessing it from the ring ctx. Signed-off-by: David Wei Reviewed-by: Pavel Begunkov Signed-off-by: Jens Axboe

io_uring: export io_[un]account_mem

2025-07-16T22:23:28+00:00

Export pinned memory accounting helpers, they'll be used by zcrx shortly. Cc: stable@vger.kernel.org Fixes: cf96310c5f9a0 ("io_uring/zcrx: add io_zcrx_area") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/9a61e54bd89289b39570ae02fe620e12487439e4.1752699568.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring/rsrc: don't rely on user vaddr alignment

2025-06-25T02:50:59+00:00

There is no guaranteed alignment for user pointers, however the calculation of an offset of the first page into a folio after coalescing uses some weird bit mask logic, get rid of it. Cc: stable@vger.kernel.org Reported-by: David Hildenbrand Fixes: a8edbb424b139 ("io_uring/rsrc: enable multi-hugepage buffer coalescing") Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/io-uring/e387b4c78b33f231105a601d84eefd8301f57954.1750771718.git.asml.silence@gmail.com/ Signed-off-by: Jens Axboe

io_uring: move io_req_put_rsrc_nodes()

2025-05-06T16:11:23+00:00

It'd be nice to hide details of how rsrc nodes are used by a request from rsrc.c, specifically which request fields store them, and what bits are signifying if there is a node in a request. It rather belong to generic request handling, so move the helper to io_uring.c. While doing so remove clearing of ->buf_node as it's controlled by REQ_F_BUF_NODE and doesn't require zeroing. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/bb73fb42baf825edb39344365aff48cdfdd4c692.1746533789.git.asml.silence@gmail.com Signed-off-by: Jens Axboe

io_uring/zcrx: improve area validation

2025-05-02T15:24:42+00:00

dmabuf backed area will be taking an offset instead of addresses, and io_buffer_validate() is not flexible enough to facilitate it. It also takes an iovec, which may truncate the u64 length zcrx takes. Add a new helper function for validation. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/0b3b735391a0a8f8971bf0121c19765131fddd3b.1746097431.git.asml.silence@gmail.com Signed-off-by: Jens Axboe