From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- fs/ntfs/bdev-io.c | 120 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 120 insertions(+) create mode 100644 fs/ntfs/bdev-io.c (limited to 'fs/ntfs/bdev-io.c') diff --git a/fs/ntfs/bdev-io.c b/fs/ntfs/bdev-io.c new file mode 100644 index 000000000..27d7c2767 --- /dev/null +++ b/fs/ntfs/bdev-io.c @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * NTFS block device I/O. + * + * Copyright (c) 2026 LG Electronics Co., Ltd. + */ + +#include + +#include "ntfs.h" + +/* + * ntfs_bdev_read - Read data directly from block device using bio + * @bdev: block device to read from + * @data: destination buffer + * @start: starting byte offset on the block device + * @size: number of bytes to read + * + * Reads @size bytes starting from byte offset @start directly from the block + * device using one or more BIOs. This function bypasses the page cache + * completely and performs synchronous I/O with REQ_META | REQ_SYNC flags set. + * + * The @start offset must be sector-aligned (512 bytes). If it is not aligned, + * the function will return -EINVAL. + * + * If the destination buffer @data is not a vmalloc address, it falls back + * to the more efficient bdev_rw_virt() helper. + * + * Return: 0 on success, negative error code on failure. + */ +int ntfs_bdev_read(struct block_device *bdev, char *data, loff_t start, size_t size) +{ + unsigned int done = 0, added; + int error; + struct bio *bio; + enum req_op op; + sector_t sector = start >> SECTOR_SHIFT; + + if (start & (SECTOR_SIZE - 1)) + return -EINVAL; + + op = REQ_OP_READ | REQ_META | REQ_SYNC; + if (!is_vmalloc_addr(data)) + return bdev_rw_virt(bdev, sector, data, size, op); + + bio = bio_alloc(bdev, + bio_max_segs(DIV_ROUND_UP(size, PAGE_SIZE)), + op, GFP_KERNEL); + bio->bi_iter.bi_sector = sector; + + do { + added = bio_add_vmalloc_chunk(bio, data + done, size - done); + if (!added) { + struct bio *prev = bio; + + bio = bio_alloc(prev->bi_bdev, + bio_max_segs(DIV_ROUND_UP(size - done, PAGE_SIZE)), + prev->bi_opf, GFP_KERNEL); + bio->bi_iter.bi_sector = bio_end_sector(prev); + bio_chain(prev, bio); + submit_bio(prev); + } + done += added; + } while (done < size); + + error = submit_bio_wait(bio); + bio_put(bio); + + if (op == REQ_OP_READ) + invalidate_kernel_vmap_range(data, size); + return error; +} + +/* + * ntfs_bdev_write - Update block device contents via page cache + * @sb: super block of the mounted NTFS filesystem + * @buf: source buffer containing data to write + * @start: starting byte offset on the block device + * @size: number of bytes to write + * + * Writes @size bytes from @buf to the block device (sb->s_bdev) starting + * at byte offset @start. The write is performed entirely through the page + * cache of the block device's address space. + */ +int ntfs_bdev_write(struct super_block *sb, void *buf, loff_t start, size_t size) +{ + pgoff_t idx, idx_end; + loff_t offset, end = start + size; + u32 from, to, buf_off = 0; + struct folio *folio; + + idx = start >> PAGE_SHIFT; + idx_end = end >> PAGE_SHIFT; + from = start & ~PAGE_MASK; + + if (idx == idx_end) + idx_end++; + + for (; idx < idx_end; idx++, from = 0) { + u32 len; + + folio = read_mapping_folio(sb->s_bdev->bd_mapping, idx, NULL); + if (IS_ERR(folio)) { + ntfs_error(sb, "Unable to read %ld page", idx); + return PTR_ERR(folio); + } + + offset = (loff_t)idx << PAGE_SHIFT; + to = min_t(u32, end - offset, PAGE_SIZE); + len = to - from; + + memcpy_to_folio(folio, from, buf + buf_off, len); + buf_off += len; + folio_mark_uptodate(folio); + folio_mark_dirty(folio); + folio_put(folio); + } + + return 0; +} -- cgit v1.3.1