block: split out operations on block special files
Add a new block/fops.c for all the file and address_space operations that provide the block special file support. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210907141303.1371844-2-hch@lst.de [axboe: correct trailing whitespace while at it] Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Christoph Hellwig
Jens Axboe
parent
49d82b1445
commit
cd82cca7eb
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@ -3,7 +3,7 @@
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# Makefile for the kernel block layer
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#
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obj-$(CONFIG_BLOCK) := bio.o elevator.o blk-core.o blk-sysfs.o \
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obj-$(CONFIG_BLOCK) := fops.o bio.o elevator.o blk-core.o blk-sysfs.o \
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blk-flush.o blk-settings.o blk-ioc.o blk-map.o \
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blk-exec.o blk-merge.o blk-timeout.o \
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blk-lib.o blk-mq.o blk-mq-tag.o blk-stat.o \
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@ -373,4 +373,6 @@ static inline void bio_clear_hipri(struct bio *bio)
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bio->bi_opf &= ~REQ_HIPRI;
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}
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extern const struct address_space_operations def_blk_aops;
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#endif /* BLK_INTERNAL_H */
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@ -0,0 +1,640 @@
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
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* Copyright (C) 2016 - 2020 Christoph Hellwig
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*/
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/blkdev.h>
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#include <linux/buffer_head.h>
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#include <linux/mpage.h>
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#include <linux/uio.h>
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#include <linux/namei.h>
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#include <linux/task_io_accounting_ops.h>
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#include <linux/falloc.h>
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#include <linux/suspend.h>
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#include "blk.h"
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static struct inode *bdev_file_inode(struct file *file)
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{
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return file->f_mapping->host;
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}
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static int blkdev_get_block(struct inode *inode, sector_t iblock,
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struct buffer_head *bh, int create)
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{
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bh->b_bdev = I_BDEV(inode);
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bh->b_blocknr = iblock;
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set_buffer_mapped(bh);
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return 0;
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}
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static unsigned int dio_bio_write_op(struct kiocb *iocb)
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{
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unsigned int op = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;
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/* avoid the need for a I/O completion work item */
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if (iocb->ki_flags & IOCB_DSYNC)
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op |= REQ_FUA;
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return op;
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}
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#define DIO_INLINE_BIO_VECS 4
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static void blkdev_bio_end_io_simple(struct bio *bio)
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{
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struct task_struct *waiter = bio->bi_private;
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WRITE_ONCE(bio->bi_private, NULL);
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blk_wake_io_task(waiter);
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}
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static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
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struct iov_iter *iter, unsigned int nr_pages)
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{
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struct file *file = iocb->ki_filp;
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struct block_device *bdev = I_BDEV(bdev_file_inode(file));
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struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs;
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loff_t pos = iocb->ki_pos;
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bool should_dirty = false;
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struct bio bio;
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ssize_t ret;
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blk_qc_t qc;
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if ((pos | iov_iter_alignment(iter)) &
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(bdev_logical_block_size(bdev) - 1))
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return -EINVAL;
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if (nr_pages <= DIO_INLINE_BIO_VECS)
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vecs = inline_vecs;
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else {
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vecs = kmalloc_array(nr_pages, sizeof(struct bio_vec),
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GFP_KERNEL);
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if (!vecs)
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return -ENOMEM;
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}
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bio_init(&bio, vecs, nr_pages);
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bio_set_dev(&bio, bdev);
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bio.bi_iter.bi_sector = pos >> 9;
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bio.bi_write_hint = iocb->ki_hint;
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bio.bi_private = current;
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bio.bi_end_io = blkdev_bio_end_io_simple;
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bio.bi_ioprio = iocb->ki_ioprio;
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ret = bio_iov_iter_get_pages(&bio, iter);
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if (unlikely(ret))
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goto out;
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ret = bio.bi_iter.bi_size;
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if (iov_iter_rw(iter) == READ) {
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bio.bi_opf = REQ_OP_READ;
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if (iter_is_iovec(iter))
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should_dirty = true;
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} else {
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bio.bi_opf = dio_bio_write_op(iocb);
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task_io_account_write(ret);
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}
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if (iocb->ki_flags & IOCB_NOWAIT)
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bio.bi_opf |= REQ_NOWAIT;
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if (iocb->ki_flags & IOCB_HIPRI)
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bio_set_polled(&bio, iocb);
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qc = submit_bio(&bio);
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for (;;) {
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set_current_state(TASK_UNINTERRUPTIBLE);
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if (!READ_ONCE(bio.bi_private))
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break;
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if (!(iocb->ki_flags & IOCB_HIPRI) ||
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!blk_poll(bdev_get_queue(bdev), qc, true))
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blk_io_schedule();
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}
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__set_current_state(TASK_RUNNING);
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bio_release_pages(&bio, should_dirty);
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if (unlikely(bio.bi_status))
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ret = blk_status_to_errno(bio.bi_status);
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out:
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if (vecs != inline_vecs)
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kfree(vecs);
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bio_uninit(&bio);
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return ret;
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}
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struct blkdev_dio {
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union {
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struct kiocb *iocb;
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struct task_struct *waiter;
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};
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size_t size;
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atomic_t ref;
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bool multi_bio : 1;
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bool should_dirty : 1;
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bool is_sync : 1;
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struct bio bio;
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};
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static struct bio_set blkdev_dio_pool;
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static int blkdev_iopoll(struct kiocb *kiocb, bool wait)
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{
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struct block_device *bdev = I_BDEV(kiocb->ki_filp->f_mapping->host);
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struct request_queue *q = bdev_get_queue(bdev);
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return blk_poll(q, READ_ONCE(kiocb->ki_cookie), wait);
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}
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static void blkdev_bio_end_io(struct bio *bio)
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{
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struct blkdev_dio *dio = bio->bi_private;
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bool should_dirty = dio->should_dirty;
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if (bio->bi_status && !dio->bio.bi_status)
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dio->bio.bi_status = bio->bi_status;
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if (!dio->multi_bio || atomic_dec_and_test(&dio->ref)) {
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if (!dio->is_sync) {
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struct kiocb *iocb = dio->iocb;
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ssize_t ret;
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if (likely(!dio->bio.bi_status)) {
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ret = dio->size;
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iocb->ki_pos += ret;
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} else {
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ret = blk_status_to_errno(dio->bio.bi_status);
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}
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dio->iocb->ki_complete(iocb, ret, 0);
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if (dio->multi_bio)
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bio_put(&dio->bio);
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} else {
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struct task_struct *waiter = dio->waiter;
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WRITE_ONCE(dio->waiter, NULL);
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blk_wake_io_task(waiter);
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}
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}
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if (should_dirty) {
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bio_check_pages_dirty(bio);
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} else {
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bio_release_pages(bio, false);
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bio_put(bio);
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}
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}
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static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
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unsigned int nr_pages)
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{
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struct file *file = iocb->ki_filp;
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struct inode *inode = bdev_file_inode(file);
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struct block_device *bdev = I_BDEV(inode);
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struct blk_plug plug;
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struct blkdev_dio *dio;
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struct bio *bio;
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bool is_poll = (iocb->ki_flags & IOCB_HIPRI) != 0;
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bool is_read = (iov_iter_rw(iter) == READ), is_sync;
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loff_t pos = iocb->ki_pos;
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blk_qc_t qc = BLK_QC_T_NONE;
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int ret = 0;
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if ((pos | iov_iter_alignment(iter)) &
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(bdev_logical_block_size(bdev) - 1))
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return -EINVAL;
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bio = bio_alloc_kiocb(iocb, nr_pages, &blkdev_dio_pool);
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dio = container_of(bio, struct blkdev_dio, bio);
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dio->is_sync = is_sync = is_sync_kiocb(iocb);
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if (dio->is_sync) {
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dio->waiter = current;
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bio_get(bio);
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} else {
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dio->iocb = iocb;
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}
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dio->size = 0;
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dio->multi_bio = false;
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dio->should_dirty = is_read && iter_is_iovec(iter);
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/*
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* Don't plug for HIPRI/polled IO, as those should go straight
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* to issue
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*/
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if (!is_poll)
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blk_start_plug(&plug);
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for (;;) {
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bio_set_dev(bio, bdev);
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bio->bi_iter.bi_sector = pos >> 9;
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bio->bi_write_hint = iocb->ki_hint;
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bio->bi_private = dio;
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bio->bi_end_io = blkdev_bio_end_io;
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bio->bi_ioprio = iocb->ki_ioprio;
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ret = bio_iov_iter_get_pages(bio, iter);
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if (unlikely(ret)) {
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bio->bi_status = BLK_STS_IOERR;
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bio_endio(bio);
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break;
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}
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if (is_read) {
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bio->bi_opf = REQ_OP_READ;
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if (dio->should_dirty)
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bio_set_pages_dirty(bio);
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} else {
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bio->bi_opf = dio_bio_write_op(iocb);
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task_io_account_write(bio->bi_iter.bi_size);
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}
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if (iocb->ki_flags & IOCB_NOWAIT)
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bio->bi_opf |= REQ_NOWAIT;
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dio->size += bio->bi_iter.bi_size;
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pos += bio->bi_iter.bi_size;
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nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS);
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if (!nr_pages) {
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bool polled = false;
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if (iocb->ki_flags & IOCB_HIPRI) {
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bio_set_polled(bio, iocb);
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polled = true;
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}
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qc = submit_bio(bio);
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if (polled)
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WRITE_ONCE(iocb->ki_cookie, qc);
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break;
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}
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if (!dio->multi_bio) {
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/*
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* AIO needs an extra reference to ensure the dio
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* structure which is embedded into the first bio
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* stays around.
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*/
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if (!is_sync)
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bio_get(bio);
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dio->multi_bio = true;
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atomic_set(&dio->ref, 2);
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} else {
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atomic_inc(&dio->ref);
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}
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submit_bio(bio);
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bio = bio_alloc(GFP_KERNEL, nr_pages);
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}
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if (!is_poll)
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blk_finish_plug(&plug);
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if (!is_sync)
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return -EIOCBQUEUED;
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for (;;) {
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set_current_state(TASK_UNINTERRUPTIBLE);
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if (!READ_ONCE(dio->waiter))
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break;
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if (!(iocb->ki_flags & IOCB_HIPRI) ||
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!blk_poll(bdev_get_queue(bdev), qc, true))
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blk_io_schedule();
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}
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__set_current_state(TASK_RUNNING);
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if (!ret)
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ret = blk_status_to_errno(dio->bio.bi_status);
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if (likely(!ret))
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ret = dio->size;
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bio_put(&dio->bio);
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return ret;
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}
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static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
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{
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unsigned int nr_pages;
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if (!iov_iter_count(iter))
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return 0;
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nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1);
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if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_VECS)
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return __blkdev_direct_IO_simple(iocb, iter, nr_pages);
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return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages));
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}
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static int blkdev_writepage(struct page *page, struct writeback_control *wbc)
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{
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return block_write_full_page(page, blkdev_get_block, wbc);
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}
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static int blkdev_readpage(struct file * file, struct page * page)
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{
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return block_read_full_page(page, blkdev_get_block);
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}
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static void blkdev_readahead(struct readahead_control *rac)
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{
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mpage_readahead(rac, blkdev_get_block);
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}
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static int blkdev_write_begin(struct file *file, struct address_space *mapping,
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loff_t pos, unsigned len, unsigned flags, struct page **pagep,
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void **fsdata)
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{
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return block_write_begin(mapping, pos, len, flags, pagep,
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blkdev_get_block);
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}
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static int blkdev_write_end(struct file *file, struct address_space *mapping,
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loff_t pos, unsigned len, unsigned copied, struct page *page,
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void *fsdata)
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{
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int ret;
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ret = block_write_end(file, mapping, pos, len, copied, page, fsdata);
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unlock_page(page);
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put_page(page);
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return ret;
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}
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static int blkdev_writepages(struct address_space *mapping,
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struct writeback_control *wbc)
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{
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return generic_writepages(mapping, wbc);
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}
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const struct address_space_operations def_blk_aops = {
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.set_page_dirty = __set_page_dirty_buffers,
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.readpage = blkdev_readpage,
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.readahead = blkdev_readahead,
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.writepage = blkdev_writepage,
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.write_begin = blkdev_write_begin,
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.write_end = blkdev_write_end,
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.writepages = blkdev_writepages,
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.direct_IO = blkdev_direct_IO,
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.migratepage = buffer_migrate_page_norefs,
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.is_dirty_writeback = buffer_check_dirty_writeback,
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};
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/*
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* for a block special file file_inode(file)->i_size is zero
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* so we compute the size by hand (just as in block_read/write above)
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*/
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static loff_t blkdev_llseek(struct file *file, loff_t offset, int whence)
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{
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struct inode *bd_inode = bdev_file_inode(file);
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loff_t retval;
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inode_lock(bd_inode);
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retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode));
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inode_unlock(bd_inode);
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return retval;
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}
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static int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
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int datasync)
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{
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struct inode *bd_inode = bdev_file_inode(filp);
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struct block_device *bdev = I_BDEV(bd_inode);
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int error;
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error = file_write_and_wait_range(filp, start, end);
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if (error)
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return error;
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/*
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* There is no need to serialise calls to blkdev_issue_flush with
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* i_mutex and doing so causes performance issues with concurrent
|
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* O_SYNC writers to a block device.
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*/
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error = blkdev_issue_flush(bdev);
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if (error == -EOPNOTSUPP)
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error = 0;
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return error;
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}
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static int blkdev_open(struct inode *inode, struct file *filp)
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{
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struct block_device *bdev;
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/*
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* Preserve backwards compatibility and allow large file access
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* even if userspace doesn't ask for it explicitly. Some mkfs
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* binary needs it. We might want to drop this workaround
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* during an unstable branch.
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*/
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filp->f_flags |= O_LARGEFILE;
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filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC;
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if (filp->f_flags & O_NDELAY)
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filp->f_mode |= FMODE_NDELAY;
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if (filp->f_flags & O_EXCL)
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filp->f_mode |= FMODE_EXCL;
|
||||
if ((filp->f_flags & O_ACCMODE) == 3)
|
||||
filp->f_mode |= FMODE_WRITE_IOCTL;
|
||||
|
||||
bdev = blkdev_get_by_dev(inode->i_rdev, filp->f_mode, filp);
|
||||
if (IS_ERR(bdev))
|
||||
return PTR_ERR(bdev);
|
||||
filp->f_mapping = bdev->bd_inode->i_mapping;
|
||||
filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int blkdev_close(struct inode *inode, struct file *filp)
|
||||
{
|
||||
struct block_device *bdev = I_BDEV(bdev_file_inode(filp));
|
||||
|
||||
blkdev_put(bdev, filp->f_mode);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
|
||||
{
|
||||
struct block_device *bdev = I_BDEV(bdev_file_inode(file));
|
||||
fmode_t mode = file->f_mode;
|
||||
|
||||
/*
|
||||
* O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
|
||||
* to updated it before every ioctl.
|
||||
*/
|
||||
if (file->f_flags & O_NDELAY)
|
||||
mode |= FMODE_NDELAY;
|
||||
else
|
||||
mode &= ~FMODE_NDELAY;
|
||||
|
||||
return blkdev_ioctl(bdev, mode, cmd, arg);
|
||||
}
|
||||
|
||||
/*
|
||||
* Write data to the block device. Only intended for the block device itself
|
||||
* and the raw driver which basically is a fake block device.
|
||||
*
|
||||
* Does not take i_mutex for the write and thus is not for general purpose
|
||||
* use.
|
||||
*/
|
||||
static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
|
||||
{
|
||||
struct file *file = iocb->ki_filp;
|
||||
struct inode *bd_inode = bdev_file_inode(file);
|
||||
loff_t size = i_size_read(bd_inode);
|
||||
struct blk_plug plug;
|
||||
size_t shorted = 0;
|
||||
ssize_t ret;
|
||||
|
||||
if (bdev_read_only(I_BDEV(bd_inode)))
|
||||
return -EPERM;
|
||||
|
||||
if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev))
|
||||
return -ETXTBSY;
|
||||
|
||||
if (!iov_iter_count(from))
|
||||
return 0;
|
||||
|
||||
if (iocb->ki_pos >= size)
|
||||
return -ENOSPC;
|
||||
|
||||
if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT)
|
||||
return -EOPNOTSUPP;
|
||||
|
||||
size -= iocb->ki_pos;
|
||||
if (iov_iter_count(from) > size) {
|
||||
shorted = iov_iter_count(from) - size;
|
||||
iov_iter_truncate(from, size);
|
||||
}
|
||||
|
||||
blk_start_plug(&plug);
|
||||
ret = __generic_file_write_iter(iocb, from);
|
||||
if (ret > 0)
|
||||
ret = generic_write_sync(iocb, ret);
|
||||
iov_iter_reexpand(from, iov_iter_count(from) + shorted);
|
||||
blk_finish_plug(&plug);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
|
||||
{
|
||||
struct file *file = iocb->ki_filp;
|
||||
struct inode *bd_inode = bdev_file_inode(file);
|
||||
loff_t size = i_size_read(bd_inode);
|
||||
loff_t pos = iocb->ki_pos;
|
||||
size_t shorted = 0;
|
||||
ssize_t ret;
|
||||
|
||||
if (pos >= size)
|
||||
return 0;
|
||||
|
||||
size -= pos;
|
||||
if (iov_iter_count(to) > size) {
|
||||
shorted = iov_iter_count(to) - size;
|
||||
iov_iter_truncate(to, size);
|
||||
}
|
||||
|
||||
ret = generic_file_read_iter(iocb, to);
|
||||
iov_iter_reexpand(to, iov_iter_count(to) + shorted);
|
||||
return ret;
|
||||
}
|
||||
|
||||
#define BLKDEV_FALLOC_FL_SUPPORTED \
|
||||
(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
|
||||
FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE)
|
||||
|
||||
static long blkdev_fallocate(struct file *file, int mode, loff_t start,
|
||||
loff_t len)
|
||||
{
|
||||
struct block_device *bdev = I_BDEV(bdev_file_inode(file));
|
||||
loff_t end = start + len - 1;
|
||||
loff_t isize;
|
||||
int error;
|
||||
|
||||
/* Fail if we don't recognize the flags. */
|
||||
if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED)
|
||||
return -EOPNOTSUPP;
|
||||
|
||||
/* Don't go off the end of the device. */
|
||||
isize = i_size_read(bdev->bd_inode);
|
||||
if (start >= isize)
|
||||
return -EINVAL;
|
||||
if (end >= isize) {
|
||||
if (mode & FALLOC_FL_KEEP_SIZE) {
|
||||
len = isize - start;
|
||||
end = start + len - 1;
|
||||
} else
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
/*
|
||||
* Don't allow IO that isn't aligned to logical block size.
|
||||
*/
|
||||
if ((start | len) & (bdev_logical_block_size(bdev) - 1))
|
||||
return -EINVAL;
|
||||
|
||||
/* Invalidate the page cache, including dirty pages. */
|
||||
error = truncate_bdev_range(bdev, file->f_mode, start, end);
|
||||
if (error)
|
||||
return error;
|
||||
|
||||
switch (mode) {
|
||||
case FALLOC_FL_ZERO_RANGE:
|
||||
case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE:
|
||||
error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
|
||||
GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
|
||||
break;
|
||||
case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:
|
||||
error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
|
||||
GFP_KERNEL, BLKDEV_ZERO_NOFALLBACK);
|
||||
break;
|
||||
case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE:
|
||||
error = blkdev_issue_discard(bdev, start >> 9, len >> 9,
|
||||
GFP_KERNEL, 0);
|
||||
break;
|
||||
default:
|
||||
return -EOPNOTSUPP;
|
||||
}
|
||||
if (error)
|
||||
return error;
|
||||
|
||||
/*
|
||||
* Invalidate the page cache again; if someone wandered in and dirtied
|
||||
* a page, we just discard it - userspace has no way of knowing whether
|
||||
* the write happened before or after discard completing...
|
||||
*/
|
||||
return truncate_bdev_range(bdev, file->f_mode, start, end);
|
||||
}
|
||||
|
||||
const struct file_operations def_blk_fops = {
|
||||
.open = blkdev_open,
|
||||
.release = blkdev_close,
|
||||
.llseek = blkdev_llseek,
|
||||
.read_iter = blkdev_read_iter,
|
||||
.write_iter = blkdev_write_iter,
|
||||
.iopoll = blkdev_iopoll,
|
||||
.mmap = generic_file_mmap,
|
||||
.fsync = blkdev_fsync,
|
||||
.unlocked_ioctl = block_ioctl,
|
||||
#ifdef CONFIG_COMPAT
|
||||
.compat_ioctl = compat_blkdev_ioctl,
|
||||
#endif
|
||||
.splice_read = generic_file_splice_read,
|
||||
.splice_write = iter_file_splice_write,
|
||||
.fallocate = blkdev_fallocate,
|
||||
};
|
||||
|
||||
static __init int blkdev_init(void)
|
||||
{
|
||||
return bioset_init(&blkdev_dio_pool, 4,
|
||||
offsetof(struct blkdev_dio, bio),
|
||||
BIOSET_NEED_BVECS|BIOSET_PERCPU_CACHE);
|
||||
}
|
||||
module_init(blkdev_init);
|
||||
637
fs/block_dev.c
637
fs/block_dev.c
|
|
@ -7,12 +7,10 @@
|
|||
|
||||
#include <linux/init.h>
|
||||
#include <linux/mm.h>
|
||||
#include <linux/fcntl.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/kmod.h>
|
||||
#include <linux/major.h>
|
||||
#include <linux/device_cgroup.h>
|
||||
#include <linux/highmem.h>
|
||||
#include <linux/blkdev.h>
|
||||
#include <linux/backing-dev.h>
|
||||
#include <linux/module.h>
|
||||
|
|
@ -20,20 +18,14 @@
|
|||
#include <linux/magic.h>
|
||||
#include <linux/buffer_head.h>
|
||||
#include <linux/swap.h>
|
||||
#include <linux/pagevec.h>
|
||||
#include <linux/writeback.h>
|
||||
#include <linux/mpage.h>
|
||||
#include <linux/mount.h>
|
||||
#include <linux/pseudo_fs.h>
|
||||
#include <linux/uio.h>
|
||||
#include <linux/namei.h>
|
||||
#include <linux/log2.h>
|
||||
#include <linux/cleancache.h>
|
||||
#include <linux/task_io_accounting_ops.h>
|
||||
#include <linux/falloc.h>
|
||||
#include <linux/part_stat.h>
|
||||
#include <linux/uaccess.h>
|
||||
#include <linux/suspend.h>
|
||||
#include "internal.h"
|
||||
#include "../block/blk.h"
|
||||
|
||||
|
|
@ -42,8 +34,6 @@ struct bdev_inode {
|
|||
struct inode vfs_inode;
|
||||
};
|
||||
|
||||
static const struct address_space_operations def_blk_aops;
|
||||
|
||||
static inline struct bdev_inode *BDEV_I(struct inode *inode)
|
||||
{
|
||||
return container_of(inode, struct bdev_inode, vfs_inode);
|
||||
|
|
@ -194,332 +184,6 @@ int sb_min_blocksize(struct super_block *sb, int size)
|
|||
|
||||
EXPORT_SYMBOL(sb_min_blocksize);
|
||||
|
||||
static int
|
||||
blkdev_get_block(struct inode *inode, sector_t iblock,
|
||||
struct buffer_head *bh, int create)
|
||||
{
|
||||
bh->b_bdev = I_BDEV(inode);
|
||||
bh->b_blocknr = iblock;
|
||||
set_buffer_mapped(bh);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct inode *bdev_file_inode(struct file *file)
|
||||
{
|
||||
return file->f_mapping->host;
|
||||
}
|
||||
|
||||
static unsigned int dio_bio_write_op(struct kiocb *iocb)
|
||||
{
|
||||
unsigned int op = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;
|
||||
|
||||
/* avoid the need for a I/O completion work item */
|
||||
if (iocb->ki_flags & IOCB_DSYNC)
|
||||
op |= REQ_FUA;
|
||||
return op;
|
||||
}
|
||||
|
||||
#define DIO_INLINE_BIO_VECS 4
|
||||
|
||||
static void blkdev_bio_end_io_simple(struct bio *bio)
|
||||
{
|
||||
struct task_struct *waiter = bio->bi_private;
|
||||
|
||||
WRITE_ONCE(bio->bi_private, NULL);
|
||||
blk_wake_io_task(waiter);
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
__blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
|
||||
unsigned int nr_pages)
|
||||
{
|
||||
struct file *file = iocb->ki_filp;
|
||||
struct block_device *bdev = I_BDEV(bdev_file_inode(file));
|
||||
struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs;
|
||||
loff_t pos = iocb->ki_pos;
|
||||
bool should_dirty = false;
|
||||
struct bio bio;
|
||||
ssize_t ret;
|
||||
blk_qc_t qc;
|
||||
|
||||
if ((pos | iov_iter_alignment(iter)) &
|
||||
(bdev_logical_block_size(bdev) - 1))
|
||||
return -EINVAL;
|
||||
|
||||
if (nr_pages <= DIO_INLINE_BIO_VECS)
|
||||
vecs = inline_vecs;
|
||||
else {
|
||||
vecs = kmalloc_array(nr_pages, sizeof(struct bio_vec),
|
||||
GFP_KERNEL);
|
||||
if (!vecs)
|
||||
return -ENOMEM;
|
||||
}
|
||||
|
||||
bio_init(&bio, vecs, nr_pages);
|
||||
bio_set_dev(&bio, bdev);
|
||||
bio.bi_iter.bi_sector = pos >> 9;
|
||||
bio.bi_write_hint = iocb->ki_hint;
|
||||
bio.bi_private = current;
|
||||
bio.bi_end_io = blkdev_bio_end_io_simple;
|
||||
bio.bi_ioprio = iocb->ki_ioprio;
|
||||
|
||||
ret = bio_iov_iter_get_pages(&bio, iter);
|
||||
if (unlikely(ret))
|
||||
goto out;
|
||||
ret = bio.bi_iter.bi_size;
|
||||
|
||||
if (iov_iter_rw(iter) == READ) {
|
||||
bio.bi_opf = REQ_OP_READ;
|
||||
if (iter_is_iovec(iter))
|
||||
should_dirty = true;
|
||||
} else {
|
||||
bio.bi_opf = dio_bio_write_op(iocb);
|
||||
task_io_account_write(ret);
|
||||
}
|
||||
if (iocb->ki_flags & IOCB_NOWAIT)
|
||||
bio.bi_opf |= REQ_NOWAIT;
|
||||
if (iocb->ki_flags & IOCB_HIPRI)
|
||||
bio_set_polled(&bio, iocb);
|
||||
|
||||
qc = submit_bio(&bio);
|
||||
for (;;) {
|
||||
set_current_state(TASK_UNINTERRUPTIBLE);
|
||||
if (!READ_ONCE(bio.bi_private))
|
||||
break;
|
||||
if (!(iocb->ki_flags & IOCB_HIPRI) ||
|
||||
!blk_poll(bdev_get_queue(bdev), qc, true))
|
||||
blk_io_schedule();
|
||||
}
|
||||
__set_current_state(TASK_RUNNING);
|
||||
|
||||
bio_release_pages(&bio, should_dirty);
|
||||
if (unlikely(bio.bi_status))
|
||||
ret = blk_status_to_errno(bio.bi_status);
|
||||
|
||||
out:
|
||||
if (vecs != inline_vecs)
|
||||
kfree(vecs);
|
||||
|
||||
bio_uninit(&bio);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
struct blkdev_dio {
|
||||
union {
|
||||
struct kiocb *iocb;
|
||||
struct task_struct *waiter;
|
||||
};
|
||||
size_t size;
|
||||
atomic_t ref;
|
||||
bool multi_bio : 1;
|
||||
bool should_dirty : 1;
|
||||
bool is_sync : 1;
|
||||
struct bio bio;
|
||||
};
|
||||
|
||||
static struct bio_set blkdev_dio_pool;
|
||||
|
||||
static int blkdev_iopoll(struct kiocb *kiocb, bool wait)
|
||||
{
|
||||
struct block_device *bdev = I_BDEV(kiocb->ki_filp->f_mapping->host);
|
||||
struct request_queue *q = bdev_get_queue(bdev);
|
||||
|
||||
return blk_poll(q, READ_ONCE(kiocb->ki_cookie), wait);
|
||||
}
|
||||
|
||||
static void blkdev_bio_end_io(struct bio *bio)
|
||||
{
|
||||
struct blkdev_dio *dio = bio->bi_private;
|
||||
bool should_dirty = dio->should_dirty;
|
||||
|
||||
if (bio->bi_status && !dio->bio.bi_status)
|
||||
dio->bio.bi_status = bio->bi_status;
|
||||
|
||||
if (!dio->multi_bio || atomic_dec_and_test(&dio->ref)) {
|
||||
if (!dio->is_sync) {
|
||||
struct kiocb *iocb = dio->iocb;
|
||||
ssize_t ret;
|
||||
|
||||
if (likely(!dio->bio.bi_status)) {
|
||||
ret = dio->size;
|
||||
iocb->ki_pos += ret;
|
||||
} else {
|
||||
ret = blk_status_to_errno(dio->bio.bi_status);
|
||||
}
|
||||
|
||||
dio->iocb->ki_complete(iocb, ret, 0);
|
||||
if (dio->multi_bio)
|
||||
bio_put(&dio->bio);
|
||||
} else {
|
||||
struct task_struct *waiter = dio->waiter;
|
||||
|
||||
WRITE_ONCE(dio->waiter, NULL);
|
||||
blk_wake_io_task(waiter);
|
||||
}
|
||||
}
|
||||
|
||||
if (should_dirty) {
|
||||
bio_check_pages_dirty(bio);
|
||||
} else {
|
||||
bio_release_pages(bio, false);
|
||||
bio_put(bio);
|
||||
}
|
||||
}
|
||||
|
||||
static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
|
||||
unsigned int nr_pages)
|
||||
{
|
||||
struct file *file = iocb->ki_filp;
|
||||
struct inode *inode = bdev_file_inode(file);
|
||||
struct block_device *bdev = I_BDEV(inode);
|
||||
struct blk_plug plug;
|
||||
struct blkdev_dio *dio;
|
||||
struct bio *bio;
|
||||
bool is_poll = (iocb->ki_flags & IOCB_HIPRI) != 0;
|
||||
bool is_read = (iov_iter_rw(iter) == READ), is_sync;
|
||||
loff_t pos = iocb->ki_pos;
|
||||
blk_qc_t qc = BLK_QC_T_NONE;
|
||||
int ret = 0;
|
||||
|
||||
if ((pos | iov_iter_alignment(iter)) &
|
||||
(bdev_logical_block_size(bdev) - 1))
|
||||
return -EINVAL;
|
||||
|
||||
bio = bio_alloc_kiocb(iocb, nr_pages, &blkdev_dio_pool);
|
||||
|
||||
dio = container_of(bio, struct blkdev_dio, bio);
|
||||
dio->is_sync = is_sync = is_sync_kiocb(iocb);
|
||||
if (dio->is_sync) {
|
||||
dio->waiter = current;
|
||||
bio_get(bio);
|
||||
} else {
|
||||
dio->iocb = iocb;
|
||||
}
|
||||
|
||||
dio->size = 0;
|
||||
dio->multi_bio = false;
|
||||
dio->should_dirty = is_read && iter_is_iovec(iter);
|
||||
|
||||
/*
|
||||
* Don't plug for HIPRI/polled IO, as those should go straight
|
||||
* to issue
|
||||
*/
|
||||
if (!is_poll)
|
||||
blk_start_plug(&plug);
|
||||
|
||||
for (;;) {
|
||||
bio_set_dev(bio, bdev);
|
||||
bio->bi_iter.bi_sector = pos >> 9;
|
||||
bio->bi_write_hint = iocb->ki_hint;
|
||||
bio->bi_private = dio;
|
||||
bio->bi_end_io = blkdev_bio_end_io;
|
||||
bio->bi_ioprio = iocb->ki_ioprio;
|
||||
|
||||
ret = bio_iov_iter_get_pages(bio, iter);
|
||||
if (unlikely(ret)) {
|
||||
bio->bi_status = BLK_STS_IOERR;
|
||||
bio_endio(bio);
|
||||
break;
|
||||
}
|
||||
|
||||
if (is_read) {
|
||||
bio->bi_opf = REQ_OP_READ;
|
||||
if (dio->should_dirty)
|
||||
bio_set_pages_dirty(bio);
|
||||
} else {
|
||||
bio->bi_opf = dio_bio_write_op(iocb);
|
||||
task_io_account_write(bio->bi_iter.bi_size);
|
||||
}
|
||||
if (iocb->ki_flags & IOCB_NOWAIT)
|
||||
bio->bi_opf |= REQ_NOWAIT;
|
||||
|
||||
dio->size += bio->bi_iter.bi_size;
|
||||
pos += bio->bi_iter.bi_size;
|
||||
|
||||
nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS);
|
||||
if (!nr_pages) {
|
||||
bool polled = false;
|
||||
|
||||
if (iocb->ki_flags & IOCB_HIPRI) {
|
||||
bio_set_polled(bio, iocb);
|
||||
polled = true;
|
||||
}
|
||||
|
||||
qc = submit_bio(bio);
|
||||
|
||||
if (polled)
|
||||
WRITE_ONCE(iocb->ki_cookie, qc);
|
||||
break;
|
||||
}
|
||||
|
||||
if (!dio->multi_bio) {
|
||||
/*
|
||||
* AIO needs an extra reference to ensure the dio
|
||||
* structure which is embedded into the first bio
|
||||
* stays around.
|
||||
*/
|
||||
if (!is_sync)
|
||||
bio_get(bio);
|
||||
dio->multi_bio = true;
|
||||
atomic_set(&dio->ref, 2);
|
||||
} else {
|
||||
atomic_inc(&dio->ref);
|
||||
}
|
||||
|
||||
submit_bio(bio);
|
||||
bio = bio_alloc(GFP_KERNEL, nr_pages);
|
||||
}
|
||||
|
||||
if (!is_poll)
|
||||
blk_finish_plug(&plug);
|
||||
|
||||
if (!is_sync)
|
||||
return -EIOCBQUEUED;
|
||||
|
||||
for (;;) {
|
||||
set_current_state(TASK_UNINTERRUPTIBLE);
|
||||
if (!READ_ONCE(dio->waiter))
|
||||
break;
|
||||
|
||||
if (!(iocb->ki_flags & IOCB_HIPRI) ||
|
||||
!blk_poll(bdev_get_queue(bdev), qc, true))
|
||||
blk_io_schedule();
|
||||
}
|
||||
__set_current_state(TASK_RUNNING);
|
||||
|
||||
if (!ret)
|
||||
ret = blk_status_to_errno(dio->bio.bi_status);
|
||||
if (likely(!ret))
|
||||
ret = dio->size;
|
||||
|
||||
bio_put(&dio->bio);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static ssize_t
|
||||
blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
|
||||
{
|
||||
unsigned int nr_pages;
|
||||
|
||||
if (!iov_iter_count(iter))
|
||||
return 0;
|
||||
|
||||
nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1);
|
||||
if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_VECS)
|
||||
return __blkdev_direct_IO_simple(iocb, iter, nr_pages);
|
||||
|
||||
return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages));
|
||||
}
|
||||
|
||||
static __init int blkdev_init(void)
|
||||
{
|
||||
return bioset_init(&blkdev_dio_pool, 4,
|
||||
offsetof(struct blkdev_dio, bio),
|
||||
BIOSET_NEED_BVECS|BIOSET_PERCPU_CACHE);
|
||||
}
|
||||
module_init(blkdev_init);
|
||||
|
||||
int __sync_blockdev(struct block_device *bdev, int wait)
|
||||
{
|
||||
if (!bdev)
|
||||
|
|
@ -637,81 +301,6 @@ int thaw_bdev(struct block_device *bdev)
|
|||
}
|
||||
EXPORT_SYMBOL(thaw_bdev);
|
||||
|
||||
static int blkdev_writepage(struct page *page, struct writeback_control *wbc)
|
||||
{
|
||||
return block_write_full_page(page, blkdev_get_block, wbc);
|
||||
}
|
||||
|
||||
static int blkdev_readpage(struct file * file, struct page * page)
|
||||
{
|
||||
return block_read_full_page(page, blkdev_get_block);
|
||||
}
|
||||
|
||||
static void blkdev_readahead(struct readahead_control *rac)
|
||||
{
|
||||
mpage_readahead(rac, blkdev_get_block);
|
||||
}
|
||||
|
||||
static int blkdev_write_begin(struct file *file, struct address_space *mapping,
|
||||
loff_t pos, unsigned len, unsigned flags,
|
||||
struct page **pagep, void **fsdata)
|
||||
{
|
||||
return block_write_begin(mapping, pos, len, flags, pagep,
|
||||
blkdev_get_block);
|
||||
}
|
||||
|
||||
static int blkdev_write_end(struct file *file, struct address_space *mapping,
|
||||
loff_t pos, unsigned len, unsigned copied,
|
||||
struct page *page, void *fsdata)
|
||||
{
|
||||
int ret;
|
||||
ret = block_write_end(file, mapping, pos, len, copied, page, fsdata);
|
||||
|
||||
unlock_page(page);
|
||||
put_page(page);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
* private llseek:
|
||||
* for a block special file file_inode(file)->i_size is zero
|
||||
* so we compute the size by hand (just as in block_read/write above)
|
||||
*/
|
||||
static loff_t block_llseek(struct file *file, loff_t offset, int whence)
|
||||
{
|
||||
struct inode *bd_inode = bdev_file_inode(file);
|
||||
loff_t retval;
|
||||
|
||||
inode_lock(bd_inode);
|
||||
retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode));
|
||||
inode_unlock(bd_inode);
|
||||
return retval;
|
||||
}
|
||||
|
||||
static int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
|
||||
int datasync)
|
||||
{
|
||||
struct inode *bd_inode = bdev_file_inode(filp);
|
||||
struct block_device *bdev = I_BDEV(bd_inode);
|
||||
int error;
|
||||
|
||||
error = file_write_and_wait_range(filp, start, end);
|
||||
if (error)
|
||||
return error;
|
||||
|
||||
/*
|
||||
* There is no need to serialise calls to blkdev_issue_flush with
|
||||
* i_mutex and doing so causes performance issues with concurrent
|
||||
* O_SYNC writers to a block device.
|
||||
*/
|
||||
error = blkdev_issue_flush(bdev);
|
||||
if (error == -EOPNOTSUPP)
|
||||
error = 0;
|
||||
|
||||
return error;
|
||||
}
|
||||
|
||||
/**
|
||||
* bdev_read_page() - Start reading a page from a block device
|
||||
* @bdev: The device to read the page from
|
||||
|
|
@ -1305,35 +894,6 @@ struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
|
|||
}
|
||||
EXPORT_SYMBOL(blkdev_get_by_path);
|
||||
|
||||
static int blkdev_open(struct inode * inode, struct file * filp)
|
||||
{
|
||||
struct block_device *bdev;
|
||||
|
||||
/*
|
||||
* Preserve backwards compatibility and allow large file access
|
||||
* even if userspace doesn't ask for it explicitly. Some mkfs
|
||||
* binary needs it. We might want to drop this workaround
|
||||
* during an unstable branch.
|
||||
*/
|
||||
filp->f_flags |= O_LARGEFILE;
|
||||
|
||||
filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC;
|
||||
|
||||
if (filp->f_flags & O_NDELAY)
|
||||
filp->f_mode |= FMODE_NDELAY;
|
||||
if (filp->f_flags & O_EXCL)
|
||||
filp->f_mode |= FMODE_EXCL;
|
||||
if ((filp->f_flags & O_ACCMODE) == 3)
|
||||
filp->f_mode |= FMODE_WRITE_IOCTL;
|
||||
|
||||
bdev = blkdev_get_by_dev(inode->i_rdev, filp->f_mode, filp);
|
||||
if (IS_ERR(bdev))
|
||||
return PTR_ERR(bdev);
|
||||
filp->f_mapping = bdev->bd_inode->i_mapping;
|
||||
filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping);
|
||||
return 0;
|
||||
}
|
||||
|
||||
void blkdev_put(struct block_device *bdev, fmode_t mode)
|
||||
{
|
||||
struct gendisk *disk = bdev->bd_disk;
|
||||
|
|
@ -1397,203 +957,6 @@ void blkdev_put(struct block_device *bdev, fmode_t mode)
|
|||
}
|
||||
EXPORT_SYMBOL(blkdev_put);
|
||||
|
||||
static int blkdev_close(struct inode * inode, struct file * filp)
|
||||
{
|
||||
struct block_device *bdev = I_BDEV(bdev_file_inode(filp));
|
||||
blkdev_put(bdev, filp->f_mode);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
|
||||
{
|
||||
struct block_device *bdev = I_BDEV(bdev_file_inode(file));
|
||||
fmode_t mode = file->f_mode;
|
||||
|
||||
/*
|
||||
* O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
|
||||
* to updated it before every ioctl.
|
||||
*/
|
||||
if (file->f_flags & O_NDELAY)
|
||||
mode |= FMODE_NDELAY;
|
||||
else
|
||||
mode &= ~FMODE_NDELAY;
|
||||
|
||||
return blkdev_ioctl(bdev, mode, cmd, arg);
|
||||
}
|
||||
|
||||
/*
|
||||
* Write data to the block device. Only intended for the block device itself
|
||||
* and the raw driver which basically is a fake block device.
|
||||
*
|
||||
* Does not take i_mutex for the write and thus is not for general purpose
|
||||
* use.
|
||||
*/
|
||||
static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
|
||||
{
|
||||
struct file *file = iocb->ki_filp;
|
||||
struct inode *bd_inode = bdev_file_inode(file);
|
||||
loff_t size = i_size_read(bd_inode);
|
||||
struct blk_plug plug;
|
||||
size_t shorted = 0;
|
||||
ssize_t ret;
|
||||
|
||||
if (bdev_read_only(I_BDEV(bd_inode)))
|
||||
return -EPERM;
|
||||
|
||||
if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev))
|
||||
return -ETXTBSY;
|
||||
|
||||
if (!iov_iter_count(from))
|
||||
return 0;
|
||||
|
||||
if (iocb->ki_pos >= size)
|
||||
return -ENOSPC;
|
||||
|
||||
if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT)
|
||||
return -EOPNOTSUPP;
|
||||
|
||||
size -= iocb->ki_pos;
|
||||
if (iov_iter_count(from) > size) {
|
||||
shorted = iov_iter_count(from) - size;
|
||||
iov_iter_truncate(from, size);
|
||||
}
|
||||
|
||||
blk_start_plug(&plug);
|
||||
ret = __generic_file_write_iter(iocb, from);
|
||||
if (ret > 0)
|
||||
ret = generic_write_sync(iocb, ret);
|
||||
iov_iter_reexpand(from, iov_iter_count(from) + shorted);
|
||||
blk_finish_plug(&plug);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
|
||||
{
|
||||
struct file *file = iocb->ki_filp;
|
||||
struct inode *bd_inode = bdev_file_inode(file);
|
||||
loff_t size = i_size_read(bd_inode);
|
||||
loff_t pos = iocb->ki_pos;
|
||||
size_t shorted = 0;
|
||||
ssize_t ret;
|
||||
|
||||
if (pos >= size)
|
||||
return 0;
|
||||
|
||||
size -= pos;
|
||||
if (iov_iter_count(to) > size) {
|
||||
shorted = iov_iter_count(to) - size;
|
||||
iov_iter_truncate(to, size);
|
||||
}
|
||||
|
||||
ret = generic_file_read_iter(iocb, to);
|
||||
iov_iter_reexpand(to, iov_iter_count(to) + shorted);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int blkdev_writepages(struct address_space *mapping,
|
||||
struct writeback_control *wbc)
|
||||
{
|
||||
return generic_writepages(mapping, wbc);
|
||||
}
|
||||
|
||||
static const struct address_space_operations def_blk_aops = {
|
||||
.set_page_dirty = __set_page_dirty_buffers,
|
||||
.readpage = blkdev_readpage,
|
||||
.readahead = blkdev_readahead,
|
||||
.writepage = blkdev_writepage,
|
||||
.write_begin = blkdev_write_begin,
|
||||
.write_end = blkdev_write_end,
|
||||
.writepages = blkdev_writepages,
|
||||
.direct_IO = blkdev_direct_IO,
|
||||
.migratepage = buffer_migrate_page_norefs,
|
||||
.is_dirty_writeback = buffer_check_dirty_writeback,
|
||||
};
|
||||
|
||||
#define BLKDEV_FALLOC_FL_SUPPORTED \
|
||||
(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
|
||||
FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE)
|
||||
|
||||
static long blkdev_fallocate(struct file *file, int mode, loff_t start,
|
||||
loff_t len)
|
||||
{
|
||||
struct block_device *bdev = I_BDEV(bdev_file_inode(file));
|
||||
loff_t end = start + len - 1;
|
||||
loff_t isize;
|
||||
int error;
|
||||
|
||||
/* Fail if we don't recognize the flags. */
|
||||
if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED)
|
||||
return -EOPNOTSUPP;
|
||||
|
||||
/* Don't go off the end of the device. */
|
||||
isize = i_size_read(bdev->bd_inode);
|
||||
if (start >= isize)
|
||||
return -EINVAL;
|
||||
if (end >= isize) {
|
||||
if (mode & FALLOC_FL_KEEP_SIZE) {
|
||||
len = isize - start;
|
||||
end = start + len - 1;
|
||||
} else
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
/*
|
||||
* Don't allow IO that isn't aligned to logical block size.
|
||||
*/
|
||||
if ((start | len) & (bdev_logical_block_size(bdev) - 1))
|
||||
return -EINVAL;
|
||||
|
||||
/* Invalidate the page cache, including dirty pages. */
|
||||
error = truncate_bdev_range(bdev, file->f_mode, start, end);
|
||||
if (error)
|
||||
return error;
|
||||
|
||||
switch (mode) {
|
||||
case FALLOC_FL_ZERO_RANGE:
|
||||
case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE:
|
||||
error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
|
||||
GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
|
||||
break;
|
||||
case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:
|
||||
error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
|
||||
GFP_KERNEL, BLKDEV_ZERO_NOFALLBACK);
|
||||
break;
|
||||
case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE:
|
||||
error = blkdev_issue_discard(bdev, start >> 9, len >> 9,
|
||||
GFP_KERNEL, 0);
|
||||
break;
|
||||
default:
|
||||
return -EOPNOTSUPP;
|
||||
}
|
||||
if (error)
|
||||
return error;
|
||||
|
||||
/*
|
||||
* Invalidate the page cache again; if someone wandered in and dirtied
|
||||
* a page, we just discard it - userspace has no way of knowing whether
|
||||
* the write happened before or after discard completing...
|
||||
*/
|
||||
return truncate_bdev_range(bdev, file->f_mode, start, end);
|
||||
}
|
||||
|
||||
const struct file_operations def_blk_fops = {
|
||||
.open = blkdev_open,
|
||||
.release = blkdev_close,
|
||||
.llseek = block_llseek,
|
||||
.read_iter = blkdev_read_iter,
|
||||
.write_iter = blkdev_write_iter,
|
||||
.iopoll = blkdev_iopoll,
|
||||
.mmap = generic_file_mmap,
|
||||
.fsync = blkdev_fsync,
|
||||
.unlocked_ioctl = block_ioctl,
|
||||
#ifdef CONFIG_COMPAT
|
||||
.compat_ioctl = compat_blkdev_ioctl,
|
||||
#endif
|
||||
.splice_read = generic_file_splice_read,
|
||||
.splice_write = iter_file_splice_write,
|
||||
.fallocate = blkdev_fallocate,
|
||||
};
|
||||
|
||||
/**
|
||||
* lookup_bdev - lookup a struct block_device by name
|
||||
* @pathname: special file representing the block device
|
||||
|
|
|
|||
Loading…
Reference in New Issue