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5218cd102a
Updates various miscellaneous operations including collation, debugging, logfile handling, unicode string processing, bdev io helpers, object id system file handling. Acked-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
118 lines
3.1 KiB
C
118 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* NTFS block device I/O.
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*
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* Copyright (c) 2026 LG Electronics Co., Ltd.
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*/
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#include <linux/blkdev.h>
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#include "ntfs.h"
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/*
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* ntfs_bdev_read - Read data directly from block device using bio
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* @bdev: block device to read from
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* @data: destination buffer
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* @start: starting byte offset on the block device
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* @size: number of bytes to read
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*
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* Reads @size bytes starting from byte offset @start directly from the block
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* device using one or more BIOs. This function bypasses the page cache
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* completely and performs synchronous I/O with REQ_META | REQ_SYNC flags set.
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*
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* The @start offset must be sector-aligned (512 bytes). If it is not aligned,
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* the function will return -EINVAL.
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*
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* If the destination buffer @data is not a vmalloc address, it falls back
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* to the more efficient bdev_rw_virt() helper.
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*
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* Return: 0 on success, negative error code on failure.
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*/
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int ntfs_bdev_read(struct block_device *bdev, char *data, loff_t start, size_t size)
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{
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unsigned int done = 0, added;
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int error;
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struct bio *bio;
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enum req_op op;
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sector_t sector = start >> SECTOR_SHIFT;
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if (start & (SECTOR_SIZE - 1))
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return -EINVAL;
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op = REQ_OP_READ | REQ_META | REQ_SYNC;
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if (!is_vmalloc_addr(data))
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return bdev_rw_virt(bdev, sector, data, size, op);
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bio = bio_alloc(bdev,
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bio_max_segs(DIV_ROUND_UP(size, PAGE_SIZE)),
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op, GFP_KERNEL);
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bio->bi_iter.bi_sector = sector;
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do {
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added = bio_add_vmalloc_chunk(bio, data + done, size - done);
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if (!added) {
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struct bio *prev = bio;
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bio = bio_alloc(prev->bi_bdev,
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bio_max_segs(DIV_ROUND_UP(size - done, PAGE_SIZE)),
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prev->bi_opf, GFP_KERNEL);
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bio->bi_iter.bi_sector = bio_end_sector(prev);
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bio_chain(prev, bio);
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submit_bio(prev);
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}
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done += added;
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} while (done < size);
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error = submit_bio_wait(bio);
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bio_put(bio);
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if (op == REQ_OP_READ)
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invalidate_kernel_vmap_range(data, size);
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return error;
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}
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/*
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* ntfs_bdev_write - Update block device contents via page cache
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* @sb: super block of the mounted NTFS filesystem
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* @buf: source buffer containing data to write
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* @start: starting byte offset on the block device
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* @size: number of bytes to write
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*
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* Writes @size bytes from @buf to the block device (sb->s_bdev) starting
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* at byte offset @start. The write is performed entirely through the page
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* cache of the block device's address space.
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*/
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int ntfs_bdev_write(struct super_block *sb, void *buf, loff_t start, size_t size)
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{
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pgoff_t idx, idx_end;
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loff_t offset, end = start + size;
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u32 from, to, buf_off = 0;
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struct folio *folio;
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idx = start >> PAGE_SHIFT;
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idx_end = end >> PAGE_SHIFT;
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from = start & ~PAGE_MASK;
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if (idx == idx_end)
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idx_end++;
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for (; idx < idx_end; idx++, from = 0) {
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folio = read_mapping_folio(sb->s_bdev->bd_mapping, idx, NULL);
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if (IS_ERR(folio)) {
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ntfs_error(sb, "Unable to read %ld page", idx);
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return PTR_ERR(folio);
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}
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offset = (loff_t)idx << PAGE_SHIFT;
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to = min_t(u32, end - offset, PAGE_SIZE);
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memcpy_to_folio(folio, from, buf + buf_off, to);
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buf_off += to;
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folio_mark_uptodate(folio);
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folio_mark_dirty(folio);
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folio_put(folio);
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}
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return 0;
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}
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