diff options
Diffstat (limited to 'fs/block_dev.c')
| -rw-r--r-- | fs/block_dev.c | 1695 |
1 files changed, 0 insertions, 1695 deletions
diff --git a/fs/block_dev.c b/fs/block_dev.c deleted file mode 100644 index 45df6cbccf12..000000000000 --- a/fs/block_dev.c +++ /dev/null @@ -1,1695 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-only -/* - * Copyright (C) 1991, 1992 Linus Torvalds - * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE - * Copyright (C) 2016 - 2020 Christoph Hellwig - */ - -#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> -#include <linux/blkpg.h> -#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" - -struct bdev_inode { - struct block_device bdev; - 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); -} - -struct block_device *I_BDEV(struct inode *inode) -{ - return &BDEV_I(inode)->bdev; -} -EXPORT_SYMBOL(I_BDEV); - -static void bdev_write_inode(struct block_device *bdev) -{ - struct inode *inode = bdev->bd_inode; - int ret; - - spin_lock(&inode->i_lock); - while (inode->i_state & I_DIRTY) { - spin_unlock(&inode->i_lock); - ret = write_inode_now(inode, true); - if (ret) { - char name[BDEVNAME_SIZE]; - pr_warn_ratelimited("VFS: Dirty inode writeback failed " - "for block device %s (err=%d).\n", - bdevname(bdev, name), ret); - } - spin_lock(&inode->i_lock); - } - spin_unlock(&inode->i_lock); -} - -/* Kill _all_ buffers and pagecache , dirty or not.. */ -static void kill_bdev(struct block_device *bdev) -{ - struct address_space *mapping = bdev->bd_inode->i_mapping; - - if (mapping_empty(mapping)) - return; - - invalidate_bh_lrus(); - truncate_inode_pages(mapping, 0); -} - -/* Invalidate clean unused buffers and pagecache. */ -void invalidate_bdev(struct block_device *bdev) -{ - struct address_space *mapping = bdev->bd_inode->i_mapping; - - if (mapping->nrpages) { - invalidate_bh_lrus(); - lru_add_drain_all(); /* make sure all lru add caches are flushed */ - invalidate_mapping_pages(mapping, 0, -1); - } - /* 99% of the time, we don't need to flush the cleancache on the bdev. - * But, for the strange corners, lets be cautious - */ - cleancache_invalidate_inode(mapping); -} -EXPORT_SYMBOL(invalidate_bdev); - -/* - * Drop all buffers & page cache for given bdev range. This function bails - * with error if bdev has other exclusive owner (such as filesystem). - */ -int truncate_bdev_range(struct block_device *bdev, fmode_t mode, - loff_t lstart, loff_t lend) -{ - /* - * If we don't hold exclusive handle for the device, upgrade to it - * while we discard the buffer cache to avoid discarding buffers - * under live filesystem. - */ - if (!(mode & FMODE_EXCL)) { - int err = bd_prepare_to_claim(bdev, truncate_bdev_range); - if (err) - goto invalidate; - } - - truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend); - if (!(mode & FMODE_EXCL)) - bd_abort_claiming(bdev, truncate_bdev_range); - return 0; - -invalidate: - /* - * Someone else has handle exclusively open. Try invalidating instead. - * The 'end' argument is inclusive so the rounding is safe. - */ - return invalidate_inode_pages2_range(bdev->bd_inode->i_mapping, - lstart >> PAGE_SHIFT, - lend >> PAGE_SHIFT); -} - -static void set_init_blocksize(struct block_device *bdev) -{ - unsigned int bsize = bdev_logical_block_size(bdev); - loff_t size = i_size_read(bdev->bd_inode); - - while (bsize < PAGE_SIZE) { - if (size & bsize) - break; - bsize <<= 1; - } - bdev->bd_inode->i_blkbits = blksize_bits(bsize); -} - -int set_blocksize(struct block_device *bdev, int size) -{ - /* Size must be a power of two, and between 512 and PAGE_SIZE */ - if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) - return -EINVAL; - - /* Size cannot be smaller than the size supported by the device */ - if (size < bdev_logical_block_size(bdev)) - return -EINVAL; - - /* Don't change the size if it is same as current */ - if (bdev->bd_inode->i_blkbits != blksize_bits(size)) { - sync_blockdev(bdev); - bdev->bd_inode->i_blkbits = blksize_bits(size); - kill_bdev(bdev); - } - return 0; -} - -EXPORT_SYMBOL(set_blocksize); - -int sb_set_blocksize(struct super_block *sb, int size) -{ - if (set_blocksize(sb->s_bdev, size)) - return 0; - /* If we get here, we know size is power of two - * and it's value is between 512 and PAGE_SIZE */ - sb->s_blocksize = size; - sb->s_blocksize_bits = blksize_bits(size); - return sb->s_blocksize; -} - -EXPORT_SYMBOL(sb_set_blocksize); - -int sb_min_blocksize(struct super_block *sb, int size) -{ - int minsize = bdev_logical_block_size(sb->s_bdev); - if (size < minsize) - size = minsize; - return sb_set_blocksize(sb, 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) - 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. - */ -int 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) - goto done; - - sb = get_active_super(bdev); - if (!sb) - goto sync; - if (sb->s_op->freeze_super) - error = sb->s_op->freeze_super(sb); - else - error = freeze_super(sb); - deactivate_super(sb); - - if (error) { - bdev->bd_fsfreeze_count--; - goto done; - } - bdev->bd_fsfreeze_sb = sb; - -sync: - sync_blockdev(bdev); -done: - mutex_unlock(&bdev->bd_fsfreeze_mutex); - return error; -} -EXPORT_SYMBOL(freeze_bdev); - -/** - * thaw_bdev -- unlock filesystem - * @bdev: blockdevice to unlock - * - * 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; - - sb = bdev->bd_fsfreeze_sb; - 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++; - else - bdev->bd_fsfreeze_sb = NULL; -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; -} - -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 - * @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; - memset(&ei->bdev, 0, sizeof(ei->bdev)); - return &ei->vfs_inode; -} - -static void bdev_free_inode(struct inode *inode) -{ - struct block_device *bdev = I_BDEV(inode); - - free_percpu(bdev->bd_stats); - kfree(bdev->bd_meta_info); - - if (!bdev_is_partition(bdev)) { - if (bdev->bd_disk && bdev->bd_disk->bdi) - bdi_put(bdev->bd_disk->bdi); - kfree(bdev->bd_disk); - } - - if (MAJOR(bdev->bd_dev) == BLOCK_EXT_MAJOR) - blk_free_ext_minor(MINOR(bdev->bd_dev)); - - kmem_cache_free(bdev_cachep, BDEV_I(inode)); -} - -static void init_once(void *data) -{ - struct bdev_inode *ei = data; - - inode_init_once(&ei->vfs_inode); -} - -static void bdev_evict_inode(struct inode *inode) -{ - truncate_inode_pages_final(&inode->i_data); - invalidate_inode_buffers(inode); /* is it needed here? */ - clear_inode(inode); -} - -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 */ -} - -struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) -{ - struct block_device *bdev; - struct inode *inode; - - inode = new_inode(blockdev_superblock); - if (!inode) - return NULL; - inode->i_mode = S_IFBLK; - inode->i_rdev = 0; - inode->i_data.a_ops = &def_blk_aops; - mapping_set_gfp_mask(&inode->i_data, GFP_USER); - - bdev = I_BDEV(inode); - mutex_init(&bdev->bd_fsfreeze_mutex); - spin_lock_init(&bdev->bd_size_lock); - bdev->bd_disk = disk; - bdev->bd_partno = partno; - bdev->bd_inode = inode; - bdev->bd_stats = alloc_percpu(struct disk_stats); - if (!bdev->bd_stats) { - iput(inode); - return NULL; - } - return bdev; -} - -void bdev_add(struct block_device *bdev, dev_t dev) -{ - bdev->bd_dev = dev; - bdev->bd_inode->i_rdev = dev; - bdev->bd_inode->i_ino = dev; - insert_inode_hash(bdev->bd_inode); -} - -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; -} - -/** - * 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 - * @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, void *holder) -{ - struct block_device *whole = bdev_whole(bdev); - - if (WARN_ON_ONCE(!holder)) - return -EINVAL; -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 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 - * @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, void *holder) -{ - struct block_device *whole = bdev_whole(bdev); - - 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 - * @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, void *holder) -{ - spin_lock(&bdev_lock); - bd_clear_claiming(bdev_whole(bdev), holder); - spin_unlock(&bdev_lock); -} -EXPORT_SYMBOL(bd_abort_claiming); - -static void blkdev_flush_mapping(struct block_device *bdev) -{ - WARN_ON_ONCE(bdev->bd_holders); - sync_blockdev(bdev); - kill_bdev(bdev); - bdev_write_inode(bdev); -} - -static int blkdev_get_whole(struct block_device *bdev, fmode_t mode) -{ - struct gendisk *disk = bdev->bd_disk; - int ret = 0; - - if (disk->fops->open) { - ret = disk->fops->open(bdev, mode); - if (ret) { - /* avoid ghost partitions on a removed medium */ - if (ret == -ENOMEDIUM && - test_bit(GD_NEED_PART_SCAN, &disk->state)) - bdev_disk_changed(disk, true); - return ret; - } - } - - if (!bdev->bd_openers) - set_init_blocksize(bdev); - if (test_bit(GD_NEED_PART_SCAN, &disk->state)) - bdev_disk_changed(disk, false); - bdev->bd_openers++; - return 0;; -} - -static void blkdev_put_whole(struct block_device *bdev, fmode_t mode) -{ - if (!--bdev->bd_openers) - blkdev_flush_mapping(bdev); - if (bdev->bd_disk->fops->release) - bdev->bd_disk->fops->release(bdev->bd_disk, mode); -} - -static int blkdev_get_part(struct block_device *part, fmode_t mode) -{ - struct gendisk *disk = part->bd_disk; - int ret; - - if (part->bd_openers) - goto done; - - ret = blkdev_get_whole(bdev_whole(part), mode); - if (ret) - return ret; - - ret = -ENXIO; - if (!bdev_nr_sectors(part)) - goto out_blkdev_put; - - disk->open_partitions++; - set_init_blocksize(part); -done: - part->bd_openers++; - return 0; - -out_blkdev_put: - blkdev_put_whole(bdev_whole(part), mode); - return ret; -} - -static void blkdev_put_part(struct block_device *part, fmode_t mode) -{ - struct block_device *whole = bdev_whole(part); - - if (--part->bd_openers) - return; - blkdev_flush_mapping(part); - whole->bd_disk->open_partitions--; - blkdev_put_whole(whole, mode); -} - -struct block_device *blkdev_get_no_open(dev_t dev) -{ - struct block_device *bdev; - struct inode *inode; - - inode = ilookup(blockdev_superblock, dev); - if (!inode) { - blk_request_module(dev); - inode = ilookup(blockdev_superblock, dev); - if (!inode) - return NULL; - } - - /* switch from the inode reference to a device mode one: */ - bdev = &BDEV_I(inode)->bdev; - if (!kobject_get_unless_zero(&bdev->bd_device.kobj)) - bdev = NULL; - iput(inode); - - if (!bdev) - return NULL; - if ((bdev->bd_disk->flags & GENHD_FL_HIDDEN) || - !try_module_get(bdev->bd_disk->fops->owner)) { - put_device(&bdev->bd_device); - return NULL; - } - - return bdev; -} - -void blkdev_put_no_open(struct block_device *bdev) -{ - module_put(bdev->bd_disk->fops->owner); - put_device(&bdev->bd_device); -} - -/** - * 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 block device described by device number @dev. If @mode includes - * %FMODE_EXCL, the block device is opened with exclusive access. Specifying - * %FMODE_EXCL with a %NULL @holder is invalid. Exclusive opens may nest for - * the same @holder. - * - * Use this interface 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. Everything else should use blkdev_get_by_path(). - * - * CONTEXT: - * Might sleep. - * - * RETURNS: - * Reference to the block_device on success, ERR_PTR(-errno) on failure. - */ -struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) -{ - bool unblock_events = true; - struct block_device *bdev; - struct gendisk *disk; - int ret; - - ret = devcgroup_check_permission(DEVCG_DEV_BLOCK, - MAJOR(dev), MINOR(dev), - ((mode & FMODE_READ) ? DEVCG_ACC_READ : 0) | - ((mode & FMODE_WRITE) ? DEVCG_ACC_WRITE : 0)); - if (ret) - return ERR_PTR(ret); - - bdev = blkdev_get_no_open(dev); - if (!bdev) - return ERR_PTR(-ENXIO); - disk = bdev->bd_disk; - - if (mode & FMODE_EXCL) { - ret = bd_prepare_to_claim(bdev, holder); - if (ret) - goto put_blkdev; - } - - disk_block_events(disk); - - mutex_lock(&disk->open_mutex); - ret = -ENXIO; - if (!disk_live(disk)) - goto abort_claiming; - if (bdev_is_partition(bdev)) - ret = blkdev_get_part(bdev, mode); - else - ret = blkdev_get_whole(bdev, mode); - if (ret) - goto abort_claiming; - if (mode & FMODE_EXCL) { - bd_finish_claiming(bdev, 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 ((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(&disk->open_mutex); - - if (unblock_events) - disk_unblock_events(disk); - return bdev; - -abort_claiming: - if (mode & FMODE_EXCL) - bd_abort_claiming(bdev, holder); - mutex_unlock(&disk->open_mutex); - disk_unblock_events(disk); -put_blkdev: - blkdev_put_no_open(bdev); - return ERR_PTR(ret); -} -EXPORT_SYMBOL(blkdev_get_by_dev); - -/** - * 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 block device described by the device file at @path. If @mode - * includes %FMODE_EXCL, the block device is opened with exclusive access. - * Specifying %FMODE_EXCL with a %NULL @holder is invalid. Exclusive opens may - * nest for the same @holder. - * - * CONTEXT: - * Might sleep. - * - * RETURNS: - * Reference to the 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; - dev_t dev; - int error; - - error = lookup_bdev(path, &dev); - if (error) - return ERR_PTR(error); - - bdev = blkdev_get_by_dev(dev, mode, holder); - if (!IS_ERR(bdev) && (mode & FMODE_WRITE) && bdev_read_only(bdev)) { - blkdev_put(bdev, mode); - return ERR_PTR(-EACCES); - } - - return bdev; -} -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; - - /* - * 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(&disk->open_mutex); - if (mode & FMODE_EXCL) { - struct block_device *whole = bdev_whole(bdev); - bool bdev_free; - - /* - * Release a claim on the device. The holder fields - * are protected with bdev_lock. open_mutex is to - * synchronize disk_holder unlinking. - */ - spin_lock(&bdev_lock); - - WARN_ON_ONCE(--bdev->bd_holders < 0); - WARN_ON_ONCE(--whole->bd_holders < 0); - - if ((bdev_free = !bdev->bd_holders)) - bdev->bd_holder = NULL; - if (!whole->bd_holders) - whole->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(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(disk, DISK_EVENT_MEDIA_CHANGE); - - if (bdev_is_partition(bdev)) - blkdev_put_part(bdev, mode); - else - blkdev_put_whole(bdev, mode); - mutex_unlock(&disk->open_mutex); - - blkdev_put_no_open(bdev); -} -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 - * @dev: return value of the block device's dev_t - * - * Get a reference to the blockdevice at @pathname in the current - * namespace if possible and return it. Return ERR_PTR(error) - * otherwise. - */ -int lookup_bdev(const char *pathname, dev_t *dev) -{ - struct inode *inode; - struct path path; - int error; - - if (!pathname || !*pathname) - return -EINVAL; - - error = kern_path(pathname, LOOKUP_FOLLOW, &path); - if (error) - return error; - - inode = d_backing_inode(path.dentry); - error = -ENOTBLK; - if (!S_ISBLK(inode->i_mode)) - goto out_path_put; - error = -EACCES; - if (!may_open_dev(&path)) - goto out_path_put; - - *dev = inode->i_rdev; - error = 0; -out_path_put: - path_put(&path); - return error; -} -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_disk->open_mutex); - if (bdev->bd_openers) - func(bdev, arg); - mutex_unlock(&bdev->bd_disk->open_mutex); - - spin_lock(&blockdev_superblock->s_inode_list_lock); - } - spin_unlock(&blockdev_superblock->s_inode_list_lock); - iput(old_inode); -} |