forked from mirrors/linux
10ed16662d
All remaining callers of bdget() outside of fs/block_dev.c want to get a reference to the struct block_device for a given struct hd_struct. Add a helper just for that and then mark bdget static. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2151 lines
54 KiB
C
2151 lines
54 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* linux/fs/block_dev.c
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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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*/
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#include <linux/init.h>
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#include <linux/mm.h>
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#include <linux/fcntl.h>
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#include <linux/slab.h>
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#include <linux/kmod.h>
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#include <linux/major.h>
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#include <linux/device_cgroup.h>
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#include <linux/highmem.h>
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#include <linux/blkdev.h>
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#include <linux/backing-dev.h>
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#include <linux/module.h>
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#include <linux/blkpg.h>
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#include <linux/magic.h>
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#include <linux/buffer_head.h>
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#include <linux/swap.h>
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#include <linux/pagevec.h>
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#include <linux/writeback.h>
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#include <linux/mpage.h>
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#include <linux/mount.h>
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#include <linux/pseudo_fs.h>
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#include <linux/uio.h>
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#include <linux/namei.h>
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#include <linux/log2.h>
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#include <linux/cleancache.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/uaccess.h>
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#include <linux/suspend.h>
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#include "internal.h"
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struct bdev_inode {
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struct block_device bdev;
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struct inode vfs_inode;
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};
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static const struct address_space_operations def_blk_aops;
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static inline struct bdev_inode *BDEV_I(struct inode *inode)
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{
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return container_of(inode, struct bdev_inode, vfs_inode);
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}
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struct block_device *I_BDEV(struct inode *inode)
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{
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return &BDEV_I(inode)->bdev;
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}
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EXPORT_SYMBOL(I_BDEV);
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static void bdev_write_inode(struct block_device *bdev)
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{
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struct inode *inode = bdev->bd_inode;
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int ret;
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spin_lock(&inode->i_lock);
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while (inode->i_state & I_DIRTY) {
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spin_unlock(&inode->i_lock);
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ret = write_inode_now(inode, true);
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if (ret) {
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char name[BDEVNAME_SIZE];
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pr_warn_ratelimited("VFS: Dirty inode writeback failed "
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"for block device %s (err=%d).\n",
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bdevname(bdev, name), ret);
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}
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spin_lock(&inode->i_lock);
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}
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spin_unlock(&inode->i_lock);
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}
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/* Kill _all_ buffers and pagecache , dirty or not.. */
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static void kill_bdev(struct block_device *bdev)
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{
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struct address_space *mapping = bdev->bd_inode->i_mapping;
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if (mapping->nrpages == 0 && mapping->nrexceptional == 0)
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return;
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invalidate_bh_lrus();
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truncate_inode_pages(mapping, 0);
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}
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/* Invalidate clean unused buffers and pagecache. */
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void invalidate_bdev(struct block_device *bdev)
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{
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struct address_space *mapping = bdev->bd_inode->i_mapping;
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if (mapping->nrpages) {
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invalidate_bh_lrus();
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lru_add_drain_all(); /* make sure all lru add caches are flushed */
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invalidate_mapping_pages(mapping, 0, -1);
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}
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/* 99% of the time, we don't need to flush the cleancache on the bdev.
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* But, for the strange corners, lets be cautious
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*/
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cleancache_invalidate_inode(mapping);
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}
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EXPORT_SYMBOL(invalidate_bdev);
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/*
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* Drop all buffers & page cache for given bdev range. This function bails
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* with error if bdev has other exclusive owner (such as filesystem).
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*/
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int truncate_bdev_range(struct block_device *bdev, fmode_t mode,
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loff_t lstart, loff_t lend)
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{
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struct block_device *claimed_bdev = NULL;
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int err;
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/*
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* If we don't hold exclusive handle for the device, upgrade to it
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* while we discard the buffer cache to avoid discarding buffers
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* under live filesystem.
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*/
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if (!(mode & FMODE_EXCL)) {
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claimed_bdev = bdev->bd_contains;
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err = bd_prepare_to_claim(bdev, claimed_bdev,
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truncate_bdev_range);
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if (err)
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return err;
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}
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truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend);
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if (claimed_bdev)
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bd_abort_claiming(bdev, claimed_bdev, truncate_bdev_range);
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return 0;
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}
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EXPORT_SYMBOL(truncate_bdev_range);
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static void set_init_blocksize(struct block_device *bdev)
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{
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bdev->bd_inode->i_blkbits = blksize_bits(bdev_logical_block_size(bdev));
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}
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int set_blocksize(struct block_device *bdev, int size)
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{
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/* Size must be a power of two, and between 512 and PAGE_SIZE */
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if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size))
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return -EINVAL;
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/* Size cannot be smaller than the size supported by the device */
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if (size < bdev_logical_block_size(bdev))
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return -EINVAL;
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/* Don't change the size if it is same as current */
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if (bdev->bd_inode->i_blkbits != blksize_bits(size)) {
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sync_blockdev(bdev);
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bdev->bd_inode->i_blkbits = blksize_bits(size);
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kill_bdev(bdev);
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}
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return 0;
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}
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EXPORT_SYMBOL(set_blocksize);
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int sb_set_blocksize(struct super_block *sb, int size)
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{
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if (set_blocksize(sb->s_bdev, size))
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return 0;
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/* If we get here, we know size is power of two
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* and it's value is between 512 and PAGE_SIZE */
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sb->s_blocksize = size;
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sb->s_blocksize_bits = blksize_bits(size);
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return sb->s_blocksize;
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}
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EXPORT_SYMBOL(sb_set_blocksize);
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int sb_min_blocksize(struct super_block *sb, int size)
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{
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int minsize = bdev_logical_block_size(sb->s_bdev);
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if (size < minsize)
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size = minsize;
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return sb_set_blocksize(sb, size);
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}
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EXPORT_SYMBOL(sb_min_blocksize);
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static int
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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 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 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
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__blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,
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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_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
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__blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, 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_bioset(GFP_KERNEL, 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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dio->size += bio->bi_iter.bi_size;
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pos += bio->bi_iter.bi_size;
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nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES);
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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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|
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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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|
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if (!is_poll)
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blk_finish_plug(&plug);
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|
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if (!is_sync)
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return -EIOCBQUEUED;
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|
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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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|
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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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|
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static ssize_t
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blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
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{
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int nr_pages;
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nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES + 1);
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if (!nr_pages)
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return 0;
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if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_PAGES)
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return __blkdev_direct_IO_simple(iocb, iter, nr_pages);
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return __blkdev_direct_IO(iocb, iter, min(nr_pages, BIO_MAX_PAGES));
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}
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|
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static __init int blkdev_init(void)
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{
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return bioset_init(&blkdev_dio_pool, 4, offsetof(struct blkdev_dio, bio), BIOSET_NEED_BVECS);
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}
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module_init(blkdev_init);
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|
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int __sync_blockdev(struct block_device *bdev, int wait)
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{
|
|
if (!bdev)
|
|
return 0;
|
|
if (!wait)
|
|
return filemap_flush(bdev->bd_inode->i_mapping);
|
|
return filemap_write_and_wait(bdev->bd_inode->i_mapping);
|
|
}
|
|
|
|
/*
|
|
* Write out and wait upon all the dirty data associated with a block
|
|
* device via its mapping. Does not take the superblock lock.
|
|
*/
|
|
int sync_blockdev(struct block_device *bdev)
|
|
{
|
|
return __sync_blockdev(bdev, 1);
|
|
}
|
|
EXPORT_SYMBOL(sync_blockdev);
|
|
|
|
/*
|
|
* Write out and wait upon all dirty data associated with this
|
|
* device. Filesystem data as well as the underlying block
|
|
* device. Takes the superblock lock.
|
|
*/
|
|
int fsync_bdev(struct block_device *bdev)
|
|
{
|
|
struct super_block *sb = get_super(bdev);
|
|
if (sb) {
|
|
int res = sync_filesystem(sb);
|
|
drop_super(sb);
|
|
return res;
|
|
}
|
|
return sync_blockdev(bdev);
|
|
}
|
|
EXPORT_SYMBOL(fsync_bdev);
|
|
|
|
/**
|
|
* freeze_bdev -- lock a filesystem and force it into a consistent state
|
|
* @bdev: blockdevice to lock
|
|
*
|
|
* If a superblock is found on this device, we take the s_umount semaphore
|
|
* on it to make sure nobody unmounts until the snapshot creation is done.
|
|
* The reference counter (bd_fsfreeze_count) guarantees that only the last
|
|
* unfreeze process can unfreeze the frozen filesystem actually when multiple
|
|
* freeze requests arrive simultaneously. It counts up in freeze_bdev() and
|
|
* count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze
|
|
* actually.
|
|
*/
|
|
struct super_block *freeze_bdev(struct block_device *bdev)
|
|
{
|
|
struct super_block *sb;
|
|
int error = 0;
|
|
|
|
mutex_lock(&bdev->bd_fsfreeze_mutex);
|
|
if (++bdev->bd_fsfreeze_count > 1) {
|
|
/*
|
|
* We don't even need to grab a reference - the first call
|
|
* to freeze_bdev grab an active reference and only the last
|
|
* thaw_bdev drops it.
|
|
*/
|
|
sb = get_super(bdev);
|
|
if (sb)
|
|
drop_super(sb);
|
|
mutex_unlock(&bdev->bd_fsfreeze_mutex);
|
|
return sb;
|
|
}
|
|
|
|
sb = get_active_super(bdev);
|
|
if (!sb)
|
|
goto out;
|
|
if (sb->s_op->freeze_super)
|
|
error = sb->s_op->freeze_super(sb);
|
|
else
|
|
error = freeze_super(sb);
|
|
if (error) {
|
|
deactivate_super(sb);
|
|
bdev->bd_fsfreeze_count--;
|
|
mutex_unlock(&bdev->bd_fsfreeze_mutex);
|
|
return ERR_PTR(error);
|
|
}
|
|
deactivate_super(sb);
|
|
out:
|
|
sync_blockdev(bdev);
|
|
mutex_unlock(&bdev->bd_fsfreeze_mutex);
|
|
return sb; /* thaw_bdev releases s->s_umount */
|
|
}
|
|
EXPORT_SYMBOL(freeze_bdev);
|
|
|
|
/**
|
|
* thaw_bdev -- unlock filesystem
|
|
* @bdev: blockdevice to unlock
|
|
* @sb: associated superblock
|
|
*
|
|
* Unlocks the filesystem and marks it writeable again after freeze_bdev().
|
|
*/
|
|
int thaw_bdev(struct block_device *bdev, struct super_block *sb)
|
|
{
|
|
int error = -EINVAL;
|
|
|
|
mutex_lock(&bdev->bd_fsfreeze_mutex);
|
|
if (!bdev->bd_fsfreeze_count)
|
|
goto out;
|
|
|
|
error = 0;
|
|
if (--bdev->bd_fsfreeze_count > 0)
|
|
goto out;
|
|
|
|
if (!sb)
|
|
goto out;
|
|
|
|
if (sb->s_op->thaw_super)
|
|
error = sb->s_op->thaw_super(sb);
|
|
else
|
|
error = thaw_super(sb);
|
|
if (error)
|
|
bdev->bd_fsfreeze_count++;
|
|
out:
|
|
mutex_unlock(&bdev->bd_fsfreeze_mutex);
|
|
return error;
|
|
}
|
|
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;
|
|
}
|
|
|
|
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, GFP_KERNEL);
|
|
if (error == -EOPNOTSUPP)
|
|
error = 0;
|
|
|
|
return error;
|
|
}
|
|
EXPORT_SYMBOL(blkdev_fsync);
|
|
|
|
/**
|
|
* bdev_read_page() - Start reading a page from a block device
|
|
* @bdev: The device to read the page from
|
|
* @sector: The offset on the device to read the page to (need not be aligned)
|
|
* @page: The page to read
|
|
*
|
|
* On entry, the page should be locked. It will be unlocked when the page
|
|
* has been read. If the block driver implements rw_page synchronously,
|
|
* that will be true on exit from this function, but it need not be.
|
|
*
|
|
* Errors returned by this function are usually "soft", eg out of memory, or
|
|
* queue full; callers should try a different route to read this page rather
|
|
* than propagate an error back up the stack.
|
|
*
|
|
* Return: negative errno if an error occurs, 0 if submission was successful.
|
|
*/
|
|
int bdev_read_page(struct block_device *bdev, sector_t sector,
|
|
struct page *page)
|
|
{
|
|
const struct block_device_operations *ops = bdev->bd_disk->fops;
|
|
int result = -EOPNOTSUPP;
|
|
|
|
if (!ops->rw_page || bdev_get_integrity(bdev))
|
|
return result;
|
|
|
|
result = blk_queue_enter(bdev->bd_disk->queue, 0);
|
|
if (result)
|
|
return result;
|
|
result = ops->rw_page(bdev, sector + get_start_sect(bdev), page,
|
|
REQ_OP_READ);
|
|
blk_queue_exit(bdev->bd_disk->queue);
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* bdev_write_page() - Start writing a page to a block device
|
|
* @bdev: The device to write the page to
|
|
* @sector: The offset on the device to write the page to (need not be aligned)
|
|
* @page: The page to write
|
|
* @wbc: The writeback_control for the write
|
|
*
|
|
* On entry, the page should be locked and not currently under writeback.
|
|
* On exit, if the write started successfully, the page will be unlocked and
|
|
* under writeback. If the write failed already (eg the driver failed to
|
|
* queue the page to the device), the page will still be locked. If the
|
|
* caller is a ->writepage implementation, it will need to unlock the page.
|
|
*
|
|
* Errors returned by this function are usually "soft", eg out of memory, or
|
|
* queue full; callers should try a different route to write this page rather
|
|
* than propagate an error back up the stack.
|
|
*
|
|
* Return: negative errno if an error occurs, 0 if submission was successful.
|
|
*/
|
|
int bdev_write_page(struct block_device *bdev, sector_t sector,
|
|
struct page *page, struct writeback_control *wbc)
|
|
{
|
|
int result;
|
|
const struct block_device_operations *ops = bdev->bd_disk->fops;
|
|
|
|
if (!ops->rw_page || bdev_get_integrity(bdev))
|
|
return -EOPNOTSUPP;
|
|
result = blk_queue_enter(bdev->bd_disk->queue, 0);
|
|
if (result)
|
|
return result;
|
|
|
|
set_page_writeback(page);
|
|
result = ops->rw_page(bdev, sector + get_start_sect(bdev), page,
|
|
REQ_OP_WRITE);
|
|
if (result) {
|
|
end_page_writeback(page);
|
|
} else {
|
|
clean_page_buffers(page);
|
|
unlock_page(page);
|
|
}
|
|
blk_queue_exit(bdev->bd_disk->queue);
|
|
return result;
|
|
}
|
|
|
|
/*
|
|
* pseudo-fs
|
|
*/
|
|
|
|
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock);
|
|
static struct kmem_cache * bdev_cachep __read_mostly;
|
|
|
|
static struct inode *bdev_alloc_inode(struct super_block *sb)
|
|
{
|
|
struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL);
|
|
if (!ei)
|
|
return NULL;
|
|
return &ei->vfs_inode;
|
|
}
|
|
|
|
static void bdev_free_inode(struct inode *inode)
|
|
{
|
|
kmem_cache_free(bdev_cachep, BDEV_I(inode));
|
|
}
|
|
|
|
static void init_once(void *foo)
|
|
{
|
|
struct bdev_inode *ei = (struct bdev_inode *) foo;
|
|
struct block_device *bdev = &ei->bdev;
|
|
|
|
memset(bdev, 0, sizeof(*bdev));
|
|
mutex_init(&bdev->bd_mutex);
|
|
#ifdef CONFIG_SYSFS
|
|
INIT_LIST_HEAD(&bdev->bd_holder_disks);
|
|
#endif
|
|
bdev->bd_bdi = &noop_backing_dev_info;
|
|
inode_init_once(&ei->vfs_inode);
|
|
/* Initialize mutex for freeze. */
|
|
mutex_init(&bdev->bd_fsfreeze_mutex);
|
|
}
|
|
|
|
static void bdev_evict_inode(struct inode *inode)
|
|
{
|
|
struct block_device *bdev = &BDEV_I(inode)->bdev;
|
|
truncate_inode_pages_final(&inode->i_data);
|
|
invalidate_inode_buffers(inode); /* is it needed here? */
|
|
clear_inode(inode);
|
|
/* Detach inode from wb early as bdi_put() may free bdi->wb */
|
|
inode_detach_wb(inode);
|
|
if (bdev->bd_bdi != &noop_backing_dev_info) {
|
|
bdi_put(bdev->bd_bdi);
|
|
bdev->bd_bdi = &noop_backing_dev_info;
|
|
}
|
|
}
|
|
|
|
static const struct super_operations bdev_sops = {
|
|
.statfs = simple_statfs,
|
|
.alloc_inode = bdev_alloc_inode,
|
|
.free_inode = bdev_free_inode,
|
|
.drop_inode = generic_delete_inode,
|
|
.evict_inode = bdev_evict_inode,
|
|
};
|
|
|
|
static int bd_init_fs_context(struct fs_context *fc)
|
|
{
|
|
struct pseudo_fs_context *ctx = init_pseudo(fc, BDEVFS_MAGIC);
|
|
if (!ctx)
|
|
return -ENOMEM;
|
|
fc->s_iflags |= SB_I_CGROUPWB;
|
|
ctx->ops = &bdev_sops;
|
|
return 0;
|
|
}
|
|
|
|
static struct file_system_type bd_type = {
|
|
.name = "bdev",
|
|
.init_fs_context = bd_init_fs_context,
|
|
.kill_sb = kill_anon_super,
|
|
};
|
|
|
|
struct super_block *blockdev_superblock __read_mostly;
|
|
EXPORT_SYMBOL_GPL(blockdev_superblock);
|
|
|
|
void __init bdev_cache_init(void)
|
|
{
|
|
int err;
|
|
static struct vfsmount *bd_mnt;
|
|
|
|
bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode),
|
|
0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT|
|
|
SLAB_MEM_SPREAD|SLAB_ACCOUNT|SLAB_PANIC),
|
|
init_once);
|
|
err = register_filesystem(&bd_type);
|
|
if (err)
|
|
panic("Cannot register bdev pseudo-fs");
|
|
bd_mnt = kern_mount(&bd_type);
|
|
if (IS_ERR(bd_mnt))
|
|
panic("Cannot create bdev pseudo-fs");
|
|
blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */
|
|
}
|
|
|
|
/*
|
|
* Most likely _very_ bad one - but then it's hardly critical for small
|
|
* /dev and can be fixed when somebody will need really large one.
|
|
* Keep in mind that it will be fed through icache hash function too.
|
|
*/
|
|
static inline unsigned long hash(dev_t dev)
|
|
{
|
|
return MAJOR(dev)+MINOR(dev);
|
|
}
|
|
|
|
static int bdev_test(struct inode *inode, void *data)
|
|
{
|
|
return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data;
|
|
}
|
|
|
|
static int bdev_set(struct inode *inode, void *data)
|
|
{
|
|
BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data;
|
|
return 0;
|
|
}
|
|
|
|
static struct block_device *bdget(dev_t dev)
|
|
{
|
|
struct block_device *bdev;
|
|
struct inode *inode;
|
|
|
|
inode = iget5_locked(blockdev_superblock, hash(dev),
|
|
bdev_test, bdev_set, &dev);
|
|
|
|
if (!inode)
|
|
return NULL;
|
|
|
|
bdev = &BDEV_I(inode)->bdev;
|
|
|
|
if (inode->i_state & I_NEW) {
|
|
spin_lock_init(&bdev->bd_size_lock);
|
|
bdev->bd_contains = NULL;
|
|
bdev->bd_super = NULL;
|
|
bdev->bd_inode = inode;
|
|
bdev->bd_part_count = 0;
|
|
inode->i_mode = S_IFBLK;
|
|
inode->i_rdev = dev;
|
|
inode->i_bdev = bdev;
|
|
inode->i_data.a_ops = &def_blk_aops;
|
|
mapping_set_gfp_mask(&inode->i_data, GFP_USER);
|
|
unlock_new_inode(inode);
|
|
}
|
|
return bdev;
|
|
}
|
|
|
|
/**
|
|
* bdgrab -- Grab a reference to an already referenced block device
|
|
* @bdev: Block device to grab a reference to.
|
|
*/
|
|
struct block_device *bdgrab(struct block_device *bdev)
|
|
{
|
|
ihold(bdev->bd_inode);
|
|
return bdev;
|
|
}
|
|
EXPORT_SYMBOL(bdgrab);
|
|
|
|
struct block_device *bdget_part(struct hd_struct *part)
|
|
{
|
|
return bdget(part_devt(part));
|
|
}
|
|
|
|
long nr_blockdev_pages(void)
|
|
{
|
|
struct inode *inode;
|
|
long ret = 0;
|
|
|
|
spin_lock(&blockdev_superblock->s_inode_list_lock);
|
|
list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list)
|
|
ret += inode->i_mapping->nrpages;
|
|
spin_unlock(&blockdev_superblock->s_inode_list_lock);
|
|
|
|
return ret;
|
|
}
|
|
|
|
void bdput(struct block_device *bdev)
|
|
{
|
|
iput(bdev->bd_inode);
|
|
}
|
|
|
|
EXPORT_SYMBOL(bdput);
|
|
|
|
static struct block_device *bd_acquire(struct inode *inode)
|
|
{
|
|
struct block_device *bdev;
|
|
|
|
spin_lock(&bdev_lock);
|
|
bdev = inode->i_bdev;
|
|
if (bdev && !inode_unhashed(bdev->bd_inode)) {
|
|
bdgrab(bdev);
|
|
spin_unlock(&bdev_lock);
|
|
return bdev;
|
|
}
|
|
spin_unlock(&bdev_lock);
|
|
|
|
/*
|
|
* i_bdev references block device inode that was already shut down
|
|
* (corresponding device got removed). Remove the reference and look
|
|
* up block device inode again just in case new device got
|
|
* reestablished under the same device number.
|
|
*/
|
|
if (bdev)
|
|
bd_forget(inode);
|
|
|
|
bdev = bdget(inode->i_rdev);
|
|
if (bdev) {
|
|
spin_lock(&bdev_lock);
|
|
if (!inode->i_bdev) {
|
|
/*
|
|
* We take an additional reference to bd_inode,
|
|
* and it's released in clear_inode() of inode.
|
|
* So, we can access it via ->i_mapping always
|
|
* without igrab().
|
|
*/
|
|
bdgrab(bdev);
|
|
inode->i_bdev = bdev;
|
|
inode->i_mapping = bdev->bd_inode->i_mapping;
|
|
}
|
|
spin_unlock(&bdev_lock);
|
|
}
|
|
return bdev;
|
|
}
|
|
|
|
/* Call when you free inode */
|
|
|
|
void bd_forget(struct inode *inode)
|
|
{
|
|
struct block_device *bdev = NULL;
|
|
|
|
spin_lock(&bdev_lock);
|
|
if (!sb_is_blkdev_sb(inode->i_sb))
|
|
bdev = inode->i_bdev;
|
|
inode->i_bdev = NULL;
|
|
inode->i_mapping = &inode->i_data;
|
|
spin_unlock(&bdev_lock);
|
|
|
|
if (bdev)
|
|
bdput(bdev);
|
|
}
|
|
|
|
/**
|
|
* bd_may_claim - test whether a block device can be claimed
|
|
* @bdev: block device of interest
|
|
* @whole: whole block device containing @bdev, may equal @bdev
|
|
* @holder: holder trying to claim @bdev
|
|
*
|
|
* Test whether @bdev can be claimed by @holder.
|
|
*
|
|
* CONTEXT:
|
|
* spin_lock(&bdev_lock).
|
|
*
|
|
* RETURNS:
|
|
* %true if @bdev can be claimed, %false otherwise.
|
|
*/
|
|
static bool bd_may_claim(struct block_device *bdev, struct block_device *whole,
|
|
void *holder)
|
|
{
|
|
if (bdev->bd_holder == holder)
|
|
return true; /* already a holder */
|
|
else if (bdev->bd_holder != NULL)
|
|
return false; /* held by someone else */
|
|
else if (whole == bdev)
|
|
return true; /* is a whole device which isn't held */
|
|
|
|
else if (whole->bd_holder == bd_may_claim)
|
|
return true; /* is a partition of a device that is being partitioned */
|
|
else if (whole->bd_holder != NULL)
|
|
return false; /* is a partition of a held device */
|
|
else
|
|
return true; /* is a partition of an un-held device */
|
|
}
|
|
|
|
/**
|
|
* bd_prepare_to_claim - claim a block device
|
|
* @bdev: block device of interest
|
|
* @whole: the whole device containing @bdev, may equal @bdev
|
|
* @holder: holder trying to claim @bdev
|
|
*
|
|
* Claim @bdev. This function fails if @bdev is already claimed by another
|
|
* holder and waits if another claiming is in progress. return, the caller
|
|
* has ownership of bd_claiming and bd_holder[s].
|
|
*
|
|
* RETURNS:
|
|
* 0 if @bdev can be claimed, -EBUSY otherwise.
|
|
*/
|
|
int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole,
|
|
void *holder)
|
|
{
|
|
retry:
|
|
spin_lock(&bdev_lock);
|
|
/* if someone else claimed, fail */
|
|
if (!bd_may_claim(bdev, whole, holder)) {
|
|
spin_unlock(&bdev_lock);
|
|
return -EBUSY;
|
|
}
|
|
|
|
/* if claiming is already in progress, wait for it to finish */
|
|
if (whole->bd_claiming) {
|
|
wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0);
|
|
DEFINE_WAIT(wait);
|
|
|
|
prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE);
|
|
spin_unlock(&bdev_lock);
|
|
schedule();
|
|
finish_wait(wq, &wait);
|
|
goto retry;
|
|
}
|
|
|
|
/* yay, all mine */
|
|
whole->bd_claiming = holder;
|
|
spin_unlock(&bdev_lock);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(bd_prepare_to_claim); /* only for the loop driver */
|
|
|
|
static struct gendisk *bdev_get_gendisk(struct block_device *bdev, int *partno)
|
|
{
|
|
struct gendisk *disk = get_gendisk(bdev->bd_dev, partno);
|
|
|
|
if (!disk)
|
|
return NULL;
|
|
/*
|
|
* Now that we hold gendisk reference we make sure bdev we looked up is
|
|
* not stale. If it is, it means device got removed and created before
|
|
* we looked up gendisk and we fail open in such case. Associating
|
|
* unhashed bdev with newly created gendisk could lead to two bdevs
|
|
* (and thus two independent caches) being associated with one device
|
|
* which is bad.
|
|
*/
|
|
if (inode_unhashed(bdev->bd_inode)) {
|
|
put_disk_and_module(disk);
|
|
return NULL;
|
|
}
|
|
return disk;
|
|
}
|
|
|
|
static void bd_clear_claiming(struct block_device *whole, void *holder)
|
|
{
|
|
lockdep_assert_held(&bdev_lock);
|
|
/* tell others that we're done */
|
|
BUG_ON(whole->bd_claiming != holder);
|
|
whole->bd_claiming = NULL;
|
|
wake_up_bit(&whole->bd_claiming, 0);
|
|
}
|
|
|
|
/**
|
|
* bd_finish_claiming - finish claiming of a block device
|
|
* @bdev: block device of interest
|
|
* @whole: whole block device
|
|
* @holder: holder that has claimed @bdev
|
|
*
|
|
* Finish exclusive open of a block device. Mark the device as exlusively
|
|
* open by the holder and wake up all waiters for exclusive open to finish.
|
|
*/
|
|
static void bd_finish_claiming(struct block_device *bdev,
|
|
struct block_device *whole, void *holder)
|
|
{
|
|
spin_lock(&bdev_lock);
|
|
BUG_ON(!bd_may_claim(bdev, whole, holder));
|
|
/*
|
|
* Note that for a whole device bd_holders will be incremented twice,
|
|
* and bd_holder will be set to bd_may_claim before being set to holder
|
|
*/
|
|
whole->bd_holders++;
|
|
whole->bd_holder = bd_may_claim;
|
|
bdev->bd_holders++;
|
|
bdev->bd_holder = holder;
|
|
bd_clear_claiming(whole, holder);
|
|
spin_unlock(&bdev_lock);
|
|
}
|
|
|
|
/**
|
|
* bd_abort_claiming - abort claiming of a block device
|
|
* @bdev: block device of interest
|
|
* @whole: whole block device
|
|
* @holder: holder that has claimed @bdev
|
|
*
|
|
* Abort claiming of a block device when the exclusive open failed. This can be
|
|
* also used when exclusive open is not actually desired and we just needed
|
|
* to block other exclusive openers for a while.
|
|
*/
|
|
void bd_abort_claiming(struct block_device *bdev, struct block_device *whole,
|
|
void *holder)
|
|
{
|
|
spin_lock(&bdev_lock);
|
|
bd_clear_claiming(whole, holder);
|
|
spin_unlock(&bdev_lock);
|
|
}
|
|
EXPORT_SYMBOL(bd_abort_claiming);
|
|
|
|
#ifdef CONFIG_SYSFS
|
|
struct bd_holder_disk {
|
|
struct list_head list;
|
|
struct gendisk *disk;
|
|
int refcnt;
|
|
};
|
|
|
|
static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev,
|
|
struct gendisk *disk)
|
|
{
|
|
struct bd_holder_disk *holder;
|
|
|
|
list_for_each_entry(holder, &bdev->bd_holder_disks, list)
|
|
if (holder->disk == disk)
|
|
return holder;
|
|
return NULL;
|
|
}
|
|
|
|
static int add_symlink(struct kobject *from, struct kobject *to)
|
|
{
|
|
return sysfs_create_link(from, to, kobject_name(to));
|
|
}
|
|
|
|
static void del_symlink(struct kobject *from, struct kobject *to)
|
|
{
|
|
sysfs_remove_link(from, kobject_name(to));
|
|
}
|
|
|
|
/**
|
|
* bd_link_disk_holder - create symlinks between holding disk and slave bdev
|
|
* @bdev: the claimed slave bdev
|
|
* @disk: the holding disk
|
|
*
|
|
* DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
|
|
*
|
|
* This functions creates the following sysfs symlinks.
|
|
*
|
|
* - from "slaves" directory of the holder @disk to the claimed @bdev
|
|
* - from "holders" directory of the @bdev to the holder @disk
|
|
*
|
|
* For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is
|
|
* passed to bd_link_disk_holder(), then:
|
|
*
|
|
* /sys/block/dm-0/slaves/sda --> /sys/block/sda
|
|
* /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
|
|
*
|
|
* The caller must have claimed @bdev before calling this function and
|
|
* ensure that both @bdev and @disk are valid during the creation and
|
|
* lifetime of these symlinks.
|
|
*
|
|
* CONTEXT:
|
|
* Might sleep.
|
|
*
|
|
* RETURNS:
|
|
* 0 on success, -errno on failure.
|
|
*/
|
|
int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
|
|
{
|
|
struct bd_holder_disk *holder;
|
|
int ret = 0;
|
|
|
|
mutex_lock(&bdev->bd_mutex);
|
|
|
|
WARN_ON_ONCE(!bdev->bd_holder);
|
|
|
|
/* FIXME: remove the following once add_disk() handles errors */
|
|
if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir))
|
|
goto out_unlock;
|
|
|
|
holder = bd_find_holder_disk(bdev, disk);
|
|
if (holder) {
|
|
holder->refcnt++;
|
|
goto out_unlock;
|
|
}
|
|
|
|
holder = kzalloc(sizeof(*holder), GFP_KERNEL);
|
|
if (!holder) {
|
|
ret = -ENOMEM;
|
|
goto out_unlock;
|
|
}
|
|
|
|
INIT_LIST_HEAD(&holder->list);
|
|
holder->disk = disk;
|
|
holder->refcnt = 1;
|
|
|
|
ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
|
|
if (ret)
|
|
goto out_free;
|
|
|
|
ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
|
|
if (ret)
|
|
goto out_del;
|
|
/*
|
|
* bdev could be deleted beneath us which would implicitly destroy
|
|
* the holder directory. Hold on to it.
|
|
*/
|
|
kobject_get(bdev->bd_part->holder_dir);
|
|
|
|
list_add(&holder->list, &bdev->bd_holder_disks);
|
|
goto out_unlock;
|
|
|
|
out_del:
|
|
del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
|
|
out_free:
|
|
kfree(holder);
|
|
out_unlock:
|
|
mutex_unlock(&bdev->bd_mutex);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(bd_link_disk_holder);
|
|
|
|
/**
|
|
* bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder()
|
|
* @bdev: the calimed slave bdev
|
|
* @disk: the holding disk
|
|
*
|
|
* DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
|
|
*
|
|
* CONTEXT:
|
|
* Might sleep.
|
|
*/
|
|
void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
|
|
{
|
|
struct bd_holder_disk *holder;
|
|
|
|
mutex_lock(&bdev->bd_mutex);
|
|
|
|
holder = bd_find_holder_disk(bdev, disk);
|
|
|
|
if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) {
|
|
del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
|
|
del_symlink(bdev->bd_part->holder_dir,
|
|
&disk_to_dev(disk)->kobj);
|
|
kobject_put(bdev->bd_part->holder_dir);
|
|
list_del_init(&holder->list);
|
|
kfree(holder);
|
|
}
|
|
|
|
mutex_unlock(&bdev->bd_mutex);
|
|
}
|
|
EXPORT_SYMBOL_GPL(bd_unlink_disk_holder);
|
|
#endif
|
|
|
|
/**
|
|
* check_disk_size_change - checks for disk size change and adjusts bdev size.
|
|
* @disk: struct gendisk to check
|
|
* @bdev: struct bdev to adjust.
|
|
* @verbose: if %true log a message about a size change if there is any
|
|
*
|
|
* This routine checks to see if the bdev size does not match the disk size
|
|
* and adjusts it if it differs. When shrinking the bdev size, its all caches
|
|
* are freed.
|
|
*/
|
|
static void check_disk_size_change(struct gendisk *disk,
|
|
struct block_device *bdev, bool verbose)
|
|
{
|
|
loff_t disk_size, bdev_size;
|
|
|
|
spin_lock(&bdev->bd_size_lock);
|
|
disk_size = (loff_t)get_capacity(disk) << 9;
|
|
bdev_size = i_size_read(bdev->bd_inode);
|
|
if (disk_size != bdev_size) {
|
|
if (verbose) {
|
|
printk(KERN_INFO
|
|
"%s: detected capacity change from %lld to %lld\n",
|
|
disk->disk_name, bdev_size, disk_size);
|
|
}
|
|
i_size_write(bdev->bd_inode, disk_size);
|
|
}
|
|
spin_unlock(&bdev->bd_size_lock);
|
|
|
|
if (bdev_size > disk_size) {
|
|
if (__invalidate_device(bdev, false))
|
|
pr_warn("VFS: busy inodes on resized disk %s\n",
|
|
disk->disk_name);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* revalidate_disk_size - checks for disk size change and adjusts bdev size.
|
|
* @disk: struct gendisk to check
|
|
* @verbose: if %true log a message about a size change if there is any
|
|
*
|
|
* This routine checks to see if the bdev size does not match the disk size
|
|
* and adjusts it if it differs. When shrinking the bdev size, its all caches
|
|
* are freed.
|
|
*/
|
|
void revalidate_disk_size(struct gendisk *disk, bool verbose)
|
|
{
|
|
struct block_device *bdev;
|
|
|
|
/*
|
|
* Hidden disks don't have associated bdev so there's no point in
|
|
* revalidating them.
|
|
*/
|
|
if (disk->flags & GENHD_FL_HIDDEN)
|
|
return;
|
|
|
|
bdev = bdget_disk(disk, 0);
|
|
if (bdev) {
|
|
check_disk_size_change(disk, bdev, verbose);
|
|
bdput(bdev);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(revalidate_disk_size);
|
|
|
|
void bd_set_nr_sectors(struct block_device *bdev, sector_t sectors)
|
|
{
|
|
spin_lock(&bdev->bd_size_lock);
|
|
i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
|
|
spin_unlock(&bdev->bd_size_lock);
|
|
}
|
|
EXPORT_SYMBOL(bd_set_nr_sectors);
|
|
|
|
static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);
|
|
|
|
int bdev_disk_changed(struct block_device *bdev, bool invalidate)
|
|
{
|
|
struct gendisk *disk = bdev->bd_disk;
|
|
int ret;
|
|
|
|
lockdep_assert_held(&bdev->bd_mutex);
|
|
|
|
clear_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state);
|
|
|
|
rescan:
|
|
ret = blk_drop_partitions(bdev);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/*
|
|
* Historically we only set the capacity to zero for devices that
|
|
* support partitions (independ of actually having partitions created).
|
|
* Doing that is rather inconsistent, but changing it broke legacy
|
|
* udisks polling for legacy ide-cdrom devices. Use the crude check
|
|
* below to get the sane behavior for most device while not breaking
|
|
* userspace for this particular setup.
|
|
*/
|
|
if (invalidate) {
|
|
if (disk_part_scan_enabled(disk) ||
|
|
!(disk->flags & GENHD_FL_REMOVABLE))
|
|
set_capacity(disk, 0);
|
|
} else {
|
|
if (disk->fops->revalidate_disk)
|
|
disk->fops->revalidate_disk(disk);
|
|
}
|
|
|
|
check_disk_size_change(disk, bdev, !invalidate);
|
|
|
|
if (get_capacity(disk)) {
|
|
ret = blk_add_partitions(disk, bdev);
|
|
if (ret == -EAGAIN)
|
|
goto rescan;
|
|
} else if (invalidate) {
|
|
/*
|
|
* Tell userspace that the media / partition table may have
|
|
* changed.
|
|
*/
|
|
kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
/*
|
|
* Only exported for for loop and dasd for historic reasons. Don't use in new
|
|
* code!
|
|
*/
|
|
EXPORT_SYMBOL_GPL(bdev_disk_changed);
|
|
|
|
/*
|
|
* bd_mutex locking:
|
|
*
|
|
* mutex_lock(part->bd_mutex)
|
|
* mutex_lock_nested(whole->bd_mutex, 1)
|
|
*/
|
|
|
|
static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder,
|
|
int for_part)
|
|
{
|
|
struct block_device *whole = NULL, *claiming = NULL;
|
|
struct gendisk *disk;
|
|
int ret;
|
|
int partno;
|
|
bool first_open = false, unblock_events = true, need_restart;
|
|
|
|
restart:
|
|
need_restart = false;
|
|
ret = -ENXIO;
|
|
disk = bdev_get_gendisk(bdev, &partno);
|
|
if (!disk)
|
|
goto out;
|
|
|
|
if (partno) {
|
|
whole = bdget_disk(disk, 0);
|
|
if (!whole) {
|
|
ret = -ENOMEM;
|
|
goto out_put_disk;
|
|
}
|
|
}
|
|
|
|
if (!for_part && (mode & FMODE_EXCL)) {
|
|
WARN_ON_ONCE(!holder);
|
|
if (whole)
|
|
claiming = whole;
|
|
else
|
|
claiming = bdev;
|
|
ret = bd_prepare_to_claim(bdev, claiming, holder);
|
|
if (ret)
|
|
goto out_put_whole;
|
|
}
|
|
|
|
disk_block_events(disk);
|
|
mutex_lock_nested(&bdev->bd_mutex, for_part);
|
|
if (!bdev->bd_openers) {
|
|
first_open = true;
|
|
bdev->bd_disk = disk;
|
|
bdev->bd_contains = bdev;
|
|
bdev->bd_partno = partno;
|
|
|
|
if (!partno) {
|
|
ret = -ENXIO;
|
|
bdev->bd_part = disk_get_part(disk, partno);
|
|
if (!bdev->bd_part)
|
|
goto out_clear;
|
|
|
|
ret = 0;
|
|
if (disk->fops->open) {
|
|
ret = disk->fops->open(bdev, mode);
|
|
/*
|
|
* If we lost a race with 'disk' being deleted,
|
|
* try again. See md.c
|
|
*/
|
|
if (ret == -ERESTARTSYS)
|
|
need_restart = true;
|
|
}
|
|
|
|
if (!ret) {
|
|
bd_set_nr_sectors(bdev, get_capacity(disk));
|
|
set_init_blocksize(bdev);
|
|
}
|
|
|
|
/*
|
|
* If the device is invalidated, rescan partition
|
|
* if open succeeded or failed with -ENOMEDIUM.
|
|
* The latter is necessary to prevent ghost
|
|
* partitions on a removed medium.
|
|
*/
|
|
if (test_bit(GD_NEED_PART_SCAN, &disk->state) &&
|
|
(!ret || ret == -ENOMEDIUM))
|
|
bdev_disk_changed(bdev, ret == -ENOMEDIUM);
|
|
|
|
if (ret)
|
|
goto out_clear;
|
|
} else {
|
|
BUG_ON(for_part);
|
|
ret = __blkdev_get(whole, mode, NULL, 1);
|
|
if (ret)
|
|
goto out_clear;
|
|
bdev->bd_contains = bdgrab(whole);
|
|
bdev->bd_part = disk_get_part(disk, partno);
|
|
if (!(disk->flags & GENHD_FL_UP) ||
|
|
!bdev->bd_part || !bdev->bd_part->nr_sects) {
|
|
ret = -ENXIO;
|
|
goto out_clear;
|
|
}
|
|
bd_set_nr_sectors(bdev, bdev->bd_part->nr_sects);
|
|
set_init_blocksize(bdev);
|
|
}
|
|
|
|
if (bdev->bd_bdi == &noop_backing_dev_info)
|
|
bdev->bd_bdi = bdi_get(disk->queue->backing_dev_info);
|
|
} else {
|
|
if (bdev->bd_contains == bdev) {
|
|
ret = 0;
|
|
if (bdev->bd_disk->fops->open)
|
|
ret = bdev->bd_disk->fops->open(bdev, mode);
|
|
/* the same as first opener case, read comment there */
|
|
if (test_bit(GD_NEED_PART_SCAN, &disk->state) &&
|
|
(!ret || ret == -ENOMEDIUM))
|
|
bdev_disk_changed(bdev, ret == -ENOMEDIUM);
|
|
if (ret)
|
|
goto out_unlock_bdev;
|
|
}
|
|
}
|
|
bdev->bd_openers++;
|
|
if (for_part)
|
|
bdev->bd_part_count++;
|
|
if (claiming)
|
|
bd_finish_claiming(bdev, claiming, holder);
|
|
|
|
/*
|
|
* Block event polling for write claims if requested. Any write holder
|
|
* makes the write_holder state stick until all are released. This is
|
|
* good enough and tracking individual writeable reference is too
|
|
* fragile given the way @mode is used in blkdev_get/put().
|
|
*/
|
|
if (claiming && (mode & FMODE_WRITE) && !bdev->bd_write_holder &&
|
|
(disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) {
|
|
bdev->bd_write_holder = true;
|
|
unblock_events = false;
|
|
}
|
|
mutex_unlock(&bdev->bd_mutex);
|
|
|
|
if (unblock_events)
|
|
disk_unblock_events(disk);
|
|
|
|
/* only one opener holds refs to the module and disk */
|
|
if (!first_open)
|
|
put_disk_and_module(disk);
|
|
if (whole)
|
|
bdput(whole);
|
|
return 0;
|
|
|
|
out_clear:
|
|
disk_put_part(bdev->bd_part);
|
|
bdev->bd_disk = NULL;
|
|
bdev->bd_part = NULL;
|
|
if (bdev != bdev->bd_contains)
|
|
__blkdev_put(bdev->bd_contains, mode, 1);
|
|
bdev->bd_contains = NULL;
|
|
out_unlock_bdev:
|
|
if (claiming)
|
|
bd_abort_claiming(bdev, claiming, holder);
|
|
mutex_unlock(&bdev->bd_mutex);
|
|
disk_unblock_events(disk);
|
|
out_put_whole:
|
|
if (whole)
|
|
bdput(whole);
|
|
out_put_disk:
|
|
put_disk_and_module(disk);
|
|
if (need_restart)
|
|
goto restart;
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* blkdev_get - open a block device
|
|
* @bdev: block_device to open
|
|
* @mode: FMODE_* mask
|
|
* @holder: exclusive holder identifier
|
|
*
|
|
* Open @bdev with @mode. If @mode includes %FMODE_EXCL, @bdev is
|
|
* open with exclusive access. Specifying %FMODE_EXCL with %NULL
|
|
* @holder is invalid. Exclusive opens may nest for the same @holder.
|
|
*
|
|
* On success, the reference count of @bdev is unchanged. On failure,
|
|
* @bdev is put.
|
|
*
|
|
* CONTEXT:
|
|
* Might sleep.
|
|
*
|
|
* RETURNS:
|
|
* 0 on success, -errno on failure.
|
|
*/
|
|
static int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
|
|
{
|
|
int ret, perm = 0;
|
|
|
|
if (mode & FMODE_READ)
|
|
perm |= MAY_READ;
|
|
if (mode & FMODE_WRITE)
|
|
perm |= MAY_WRITE;
|
|
ret = devcgroup_inode_permission(bdev->bd_inode, perm);
|
|
if (ret)
|
|
goto bdput;
|
|
|
|
ret =__blkdev_get(bdev, mode, holder, 0);
|
|
if (ret)
|
|
goto bdput;
|
|
return 0;
|
|
|
|
bdput:
|
|
bdput(bdev);
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* blkdev_get_by_path - open a block device by name
|
|
* @path: path to the block device to open
|
|
* @mode: FMODE_* mask
|
|
* @holder: exclusive holder identifier
|
|
*
|
|
* Open the blockdevice described by the device file at @path. @mode
|
|
* and @holder are identical to blkdev_get().
|
|
*
|
|
* On success, the returned block_device has reference count of one.
|
|
*
|
|
* CONTEXT:
|
|
* Might sleep.
|
|
*
|
|
* RETURNS:
|
|
* Pointer to block_device on success, ERR_PTR(-errno) on failure.
|
|
*/
|
|
struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
|
|
void *holder)
|
|
{
|
|
struct block_device *bdev;
|
|
int err;
|
|
|
|
bdev = lookup_bdev(path);
|
|
if (IS_ERR(bdev))
|
|
return bdev;
|
|
|
|
err = blkdev_get(bdev, mode, holder);
|
|
if (err)
|
|
return ERR_PTR(err);
|
|
|
|
if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) {
|
|
blkdev_put(bdev, mode);
|
|
return ERR_PTR(-EACCES);
|
|
}
|
|
|
|
return bdev;
|
|
}
|
|
EXPORT_SYMBOL(blkdev_get_by_path);
|
|
|
|
/**
|
|
* blkdev_get_by_dev - open a block device by device number
|
|
* @dev: device number of block device to open
|
|
* @mode: FMODE_* mask
|
|
* @holder: exclusive holder identifier
|
|
*
|
|
* Open the blockdevice described by device number @dev. @mode and
|
|
* @holder are identical to blkdev_get().
|
|
*
|
|
* Use it ONLY if you really do not have anything better - i.e. when
|
|
* you are behind a truly sucky interface and all you are given is a
|
|
* device number. _Never_ to be used for internal purposes. If you
|
|
* ever need it - reconsider your API.
|
|
*
|
|
* On success, the returned block_device has reference count of one.
|
|
*
|
|
* CONTEXT:
|
|
* Might sleep.
|
|
*
|
|
* RETURNS:
|
|
* Pointer to block_device on success, ERR_PTR(-errno) on failure.
|
|
*/
|
|
struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder)
|
|
{
|
|
struct block_device *bdev;
|
|
int err;
|
|
|
|
bdev = bdget(dev);
|
|
if (!bdev)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
err = blkdev_get(bdev, mode, holder);
|
|
if (err)
|
|
return ERR_PTR(err);
|
|
|
|
return bdev;
|
|
}
|
|
EXPORT_SYMBOL(blkdev_get_by_dev);
|
|
|
|
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 = bd_acquire(inode);
|
|
if (bdev == NULL)
|
|
return -ENOMEM;
|
|
|
|
filp->f_mapping = bdev->bd_inode->i_mapping;
|
|
filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping);
|
|
|
|
return blkdev_get(bdev, filp->f_mode, filp);
|
|
}
|
|
|
|
static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
|
|
{
|
|
struct gendisk *disk = bdev->bd_disk;
|
|
struct block_device *victim = NULL;
|
|
|
|
/*
|
|
* Sync early if it looks like we're the last one. If someone else
|
|
* opens the block device between now and the decrement of bd_openers
|
|
* then we did a sync that we didn't need to, but that's not the end
|
|
* of the world and we want to avoid long (could be several minute)
|
|
* syncs while holding the mutex.
|
|
*/
|
|
if (bdev->bd_openers == 1)
|
|
sync_blockdev(bdev);
|
|
|
|
mutex_lock_nested(&bdev->bd_mutex, for_part);
|
|
if (for_part)
|
|
bdev->bd_part_count--;
|
|
|
|
if (!--bdev->bd_openers) {
|
|
WARN_ON_ONCE(bdev->bd_holders);
|
|
sync_blockdev(bdev);
|
|
kill_bdev(bdev);
|
|
|
|
bdev_write_inode(bdev);
|
|
}
|
|
if (bdev->bd_contains == bdev) {
|
|
if (disk->fops->release)
|
|
disk->fops->release(disk, mode);
|
|
}
|
|
if (!bdev->bd_openers) {
|
|
disk_put_part(bdev->bd_part);
|
|
bdev->bd_part = NULL;
|
|
bdev->bd_disk = NULL;
|
|
if (bdev != bdev->bd_contains)
|
|
victim = bdev->bd_contains;
|
|
bdev->bd_contains = NULL;
|
|
|
|
put_disk_and_module(disk);
|
|
}
|
|
mutex_unlock(&bdev->bd_mutex);
|
|
bdput(bdev);
|
|
if (victim)
|
|
__blkdev_put(victim, mode, 1);
|
|
}
|
|
|
|
void blkdev_put(struct block_device *bdev, fmode_t mode)
|
|
{
|
|
mutex_lock(&bdev->bd_mutex);
|
|
|
|
if (mode & FMODE_EXCL) {
|
|
bool bdev_free;
|
|
|
|
/*
|
|
* Release a claim on the device. The holder fields
|
|
* are protected with bdev_lock. bd_mutex is to
|
|
* synchronize disk_holder unlinking.
|
|
*/
|
|
spin_lock(&bdev_lock);
|
|
|
|
WARN_ON_ONCE(--bdev->bd_holders < 0);
|
|
WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0);
|
|
|
|
/* bd_contains might point to self, check in a separate step */
|
|
if ((bdev_free = !bdev->bd_holders))
|
|
bdev->bd_holder = NULL;
|
|
if (!bdev->bd_contains->bd_holders)
|
|
bdev->bd_contains->bd_holder = NULL;
|
|
|
|
spin_unlock(&bdev_lock);
|
|
|
|
/*
|
|
* If this was the last claim, remove holder link and
|
|
* unblock evpoll if it was a write holder.
|
|
*/
|
|
if (bdev_free && bdev->bd_write_holder) {
|
|
disk_unblock_events(bdev->bd_disk);
|
|
bdev->bd_write_holder = false;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Trigger event checking and tell drivers to flush MEDIA_CHANGE
|
|
* event. This is to ensure detection of media removal commanded
|
|
* from userland - e.g. eject(1).
|
|
*/
|
|
disk_flush_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE);
|
|
|
|
mutex_unlock(&bdev->bd_mutex);
|
|
|
|
__blkdev_put(bdev, mode, 0);
|
|
}
|
|
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.
|
|
*/
|
|
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;
|
|
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;
|
|
|
|
iov_iter_truncate(from, size - iocb->ki_pos);
|
|
|
|
blk_start_plug(&plug);
|
|
ret = __generic_file_write_iter(iocb, from);
|
|
if (ret > 0)
|
|
ret = generic_write_sync(iocb, ret);
|
|
blk_finish_plug(&plug);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blkdev_write_iter);
|
|
|
|
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;
|
|
|
|
if (pos >= size)
|
|
return 0;
|
|
|
|
size -= pos;
|
|
iov_iter_truncate(to, size);
|
|
return generic_file_read_iter(iocb, to);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blkdev_read_iter);
|
|
|
|
/*
|
|
* Try to release a page associated with block device when the system
|
|
* is under memory pressure.
|
|
*/
|
|
static int blkdev_releasepage(struct page *page, gfp_t wait)
|
|
{
|
|
struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super;
|
|
|
|
if (super && super->s_op->bdev_try_to_free_page)
|
|
return super->s_op->bdev_try_to_free_page(super, page, wait);
|
|
|
|
return try_to_free_buffers(page);
|
|
}
|
|
|
|
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 = {
|
|
.readpage = blkdev_readpage,
|
|
.readahead = blkdev_readahead,
|
|
.writepage = blkdev_writepage,
|
|
.write_begin = blkdev_write_begin,
|
|
.write_end = blkdev_write_end,
|
|
.writepages = blkdev_writepages,
|
|
.releasepage = blkdev_releasepage,
|
|
.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 again; if someone wandered in and dirtied a page,
|
|
* the caller will be given -EBUSY. The third argument is
|
|
* inclusive, so the rounding here is safe.
|
|
*/
|
|
return invalidate_inode_pages2_range(bdev->bd_inode->i_mapping,
|
|
start >> PAGE_SHIFT,
|
|
end >> PAGE_SHIFT);
|
|
}
|
|
|
|
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
|
|
*
|
|
* Get a reference to the blockdevice at @pathname in the current
|
|
* namespace if possible and return it. Return ERR_PTR(error)
|
|
* otherwise.
|
|
*/
|
|
struct block_device *lookup_bdev(const char *pathname)
|
|
{
|
|
struct block_device *bdev;
|
|
struct inode *inode;
|
|
struct path path;
|
|
int error;
|
|
|
|
if (!pathname || !*pathname)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
error = kern_path(pathname, LOOKUP_FOLLOW, &path);
|
|
if (error)
|
|
return ERR_PTR(error);
|
|
|
|
inode = d_backing_inode(path.dentry);
|
|
error = -ENOTBLK;
|
|
if (!S_ISBLK(inode->i_mode))
|
|
goto fail;
|
|
error = -EACCES;
|
|
if (!may_open_dev(&path))
|
|
goto fail;
|
|
error = -ENOMEM;
|
|
bdev = bd_acquire(inode);
|
|
if (!bdev)
|
|
goto fail;
|
|
out:
|
|
path_put(&path);
|
|
return bdev;
|
|
fail:
|
|
bdev = ERR_PTR(error);
|
|
goto out;
|
|
}
|
|
EXPORT_SYMBOL(lookup_bdev);
|
|
|
|
int __invalidate_device(struct block_device *bdev, bool kill_dirty)
|
|
{
|
|
struct super_block *sb = get_super(bdev);
|
|
int res = 0;
|
|
|
|
if (sb) {
|
|
/*
|
|
* no need to lock the super, get_super holds the
|
|
* read mutex so the filesystem cannot go away
|
|
* under us (->put_super runs with the write lock
|
|
* hold).
|
|
*/
|
|
shrink_dcache_sb(sb);
|
|
res = invalidate_inodes(sb, kill_dirty);
|
|
drop_super(sb);
|
|
}
|
|
invalidate_bdev(bdev);
|
|
return res;
|
|
}
|
|
EXPORT_SYMBOL(__invalidate_device);
|
|
|
|
void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg)
|
|
{
|
|
struct inode *inode, *old_inode = NULL;
|
|
|
|
spin_lock(&blockdev_superblock->s_inode_list_lock);
|
|
list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) {
|
|
struct address_space *mapping = inode->i_mapping;
|
|
struct block_device *bdev;
|
|
|
|
spin_lock(&inode->i_lock);
|
|
if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) ||
|
|
mapping->nrpages == 0) {
|
|
spin_unlock(&inode->i_lock);
|
|
continue;
|
|
}
|
|
__iget(inode);
|
|
spin_unlock(&inode->i_lock);
|
|
spin_unlock(&blockdev_superblock->s_inode_list_lock);
|
|
/*
|
|
* We hold a reference to 'inode' so it couldn't have been
|
|
* removed from s_inodes list while we dropped the
|
|
* s_inode_list_lock We cannot iput the inode now as we can
|
|
* be holding the last reference and we cannot iput it under
|
|
* s_inode_list_lock. So we keep the reference and iput it
|
|
* later.
|
|
*/
|
|
iput(old_inode);
|
|
old_inode = inode;
|
|
bdev = I_BDEV(inode);
|
|
|
|
mutex_lock(&bdev->bd_mutex);
|
|
if (bdev->bd_openers)
|
|
func(bdev, arg);
|
|
mutex_unlock(&bdev->bd_mutex);
|
|
|
|
spin_lock(&blockdev_superblock->s_inode_list_lock);
|
|
}
|
|
spin_unlock(&blockdev_superblock->s_inode_list_lock);
|
|
iput(old_inode);
|
|
}
|