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fs/block_dev.c
41 KB
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/* * linux/fs/block_dev.c * * Copyright (C) 1991, 1992 Linus Torvalds * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE */ |
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#include <linux/init.h> #include <linux/mm.h> #include <linux/fcntl.h> #include <linux/slab.h> #include <linux/kmod.h> #include <linux/major.h> |
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#include <linux/device_cgroup.h> |
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#include <linux/highmem.h> #include <linux/blkdev.h> #include <linux/module.h> #include <linux/blkpg.h> #include <linux/buffer_head.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> #include <linux/mount.h> #include <linux/uio.h> #include <linux/namei.h> |
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#include <linux/log2.h> |
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#include <linux/kmemleak.h> |
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#include <asm/uaccess.h> |
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#include "internal.h" |
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struct bdev_inode { struct block_device bdev; struct inode vfs_inode; }; |
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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) { return container_of(inode, struct bdev_inode, vfs_inode); } inline struct block_device *I_BDEV(struct inode *inode) { return &BDEV_I(inode)->bdev; } |
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EXPORT_SYMBOL(I_BDEV); |
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/* |
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* Move the inode from its current bdi to a new bdi. If the inode is dirty we * need to move it onto the dirty list of @dst so that the inode is always on * the right list. |
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*/ static void bdev_inode_switch_bdi(struct inode *inode, struct backing_dev_info *dst) { |
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struct backing_dev_info *old = inode->i_data.backing_dev_info; if (unlikely(dst == old)) /* deadlock avoidance */ return; bdi_lock_two(&old->wb, &dst->wb); |
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spin_lock(&inode->i_lock); |
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inode->i_data.backing_dev_info = dst; if (inode->i_state & I_DIRTY) |
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list_move(&inode->i_wb_list, &dst->wb.b_dirty); |
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spin_unlock(&inode->i_lock); |
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spin_unlock(&old->wb.list_lock); spin_unlock(&dst->wb.list_lock); |
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} |
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static sector_t max_block(struct block_device *bdev) { sector_t retval = ~((sector_t)0); loff_t sz = i_size_read(bdev->bd_inode); if (sz) { unsigned int size = block_size(bdev); unsigned int sizebits = blksize_bits(size); retval = (sz >> sizebits); } return retval; } |
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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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if (bdev->bd_inode->i_mapping->nrpages == 0) return; invalidate_bh_lrus(); |
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truncate_inode_pages(bdev->bd_inode->i_mapping, 0); } int set_blocksize(struct block_device *bdev, int size) { /* 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; /* 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; /* Don't change the size if it is same as current */ if (bdev->bd_block_size != size) { sync_blockdev(bdev); bdev->bd_block_size = size; 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) { |
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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; |
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sb->s_blocksize_bits = blksize_bits(size); |
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return sb->s_blocksize; } EXPORT_SYMBOL(sb_set_blocksize); int sb_min_blocksize(struct super_block *sb, int size) { |
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int minsize = bdev_logical_block_size(sb->s_bdev); |
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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) { if (iblock >= max_block(I_BDEV(inode))) { if (create) return -EIO; /* * for reads, we're just trying to fill a partial page. * return a hole, they will have to call get_block again * before they can fill it, and they will get -EIO at that * time */ return 0; } bh->b_bdev = I_BDEV(inode); bh->b_blocknr = iblock; set_buffer_mapped(bh); return 0; } |
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static int blkdev_get_blocks(struct inode *inode, sector_t iblock, struct buffer_head *bh, int create) { sector_t end_block = max_block(I_BDEV(inode)); unsigned long max_blocks = bh->b_size >> inode->i_blkbits; if ((iblock + max_blocks) > end_block) { max_blocks = end_block - iblock; if ((long)max_blocks <= 0) { if (create) return -EIO; /* write fully beyond EOF */ /* * It is a read which is fully beyond EOF. We return * a !buffer_mapped buffer */ max_blocks = 0; } } bh->b_bdev = I_BDEV(inode); bh->b_blocknr = iblock; bh->b_size = max_blocks << inode->i_blkbits; if (max_blocks) set_buffer_mapped(bh); return 0; } static ssize_t blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t offset, unsigned long nr_segs) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; |
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return __blockdev_direct_IO(rw, iocb, inode, I_BDEV(inode), iov, offset, nr_segs, blkdev_get_blocks, NULL, NULL, 0); |
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} |
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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); } |
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/* * 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) { |
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return __sync_blockdev(bdev, 1); |
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} 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) { |
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int res = sync_filesystem(sb); |
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drop_super(sb); return res; } return sync_blockdev(bdev); } |
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EXPORT_SYMBOL(fsync_bdev); |
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/** * freeze_bdev -- lock a filesystem and force it into a consistent state * @bdev: blockdevice to lock * |
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* 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); |
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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. */ |
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sb = get_super(bdev); |
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drop_super(sb); mutex_unlock(&bdev->bd_fsfreeze_mutex); return sb; } sb = get_active_super(bdev); if (!sb) goto out; |
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error = freeze_super(sb); if (error) { deactivate_super(sb); bdev->bd_fsfreeze_count--; |
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mutex_unlock(&bdev->bd_fsfreeze_mutex); |
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return ERR_PTR(error); |
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} |
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deactivate_super(sb); |
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out: |
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sync_blockdev(bdev); mutex_unlock(&bdev->bd_fsfreeze_mutex); |
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return sb; /* thaw_bdev releases s->s_umount */ |
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} 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) { |
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int error = -EINVAL; |
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mutex_lock(&bdev->bd_fsfreeze_mutex); |
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if (!bdev->bd_fsfreeze_count) |
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goto out; |
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error = 0; if (--bdev->bd_fsfreeze_count > 0) |
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goto out; |
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if (!sb) |
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goto out; |
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error = thaw_super(sb); if (error) { bdev->bd_fsfreeze_count++; mutex_unlock(&bdev->bd_fsfreeze_mutex); return error; } out: |
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mutex_unlock(&bdev->bd_fsfreeze_mutex); return 0; } EXPORT_SYMBOL(thaw_bdev); |
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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); } |
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static int blkdev_write_begin(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata) |
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{ |
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return block_write_begin(mapping, pos, len, flags, pagep, blkdev_get_block); |
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} |
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static int blkdev_write_end(struct file *file, struct address_space *mapping, loff_t pos, unsigned len, unsigned copied, struct page *page, void *fsdata) |
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{ |
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int ret; ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); unlock_page(page); page_cache_release(page); return ret; |
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} /* * private llseek: |
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* for a block special file file->f_path.dentry->d_inode->i_size is zero |
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* 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 origin) { struct inode *bd_inode = file->f_mapping->host; loff_t size; loff_t retval; |
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mutex_lock(&bd_inode->i_mutex); |
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size = i_size_read(bd_inode); |
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retval = -EINVAL; |
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switch (origin) { |
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case SEEK_END: |
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offset += size; break; |
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case SEEK_CUR: |
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offset += file->f_pos; |
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case SEEK_SET: break; default: goto out; |
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} |
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if (offset >= 0 && offset <= size) { if (offset != file->f_pos) { file->f_pos = offset; } retval = offset; } |
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out: |
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mutex_unlock(&bd_inode->i_mutex); |
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return retval; } |
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int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync) |
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{ |
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struct inode *bd_inode = filp->f_mapping->host; struct block_device *bdev = I_BDEV(bd_inode); |
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int error; |
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error = filemap_write_and_wait_range(filp->f_mapping, start, end); if (error) return error; |
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/* * 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. */ |
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error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL); |
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if (error == -EOPNOTSUPP) error = 0; |
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return error; |
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} |
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EXPORT_SYMBOL(blkdev_fsync); |
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/* * pseudo-fs */ static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); |
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static struct kmem_cache * bdev_cachep __read_mostly; |
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static struct inode *bdev_alloc_inode(struct super_block *sb) { |
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struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); |
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if (!ei) return NULL; return &ei->vfs_inode; } |
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static void bdev_i_callback(struct rcu_head *head) |
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{ |
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struct inode *inode = container_of(head, struct inode, i_rcu); |
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struct bdev_inode *bdi = BDEV_I(inode); |
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kmem_cache_free(bdev_cachep, bdi); } |
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static void bdev_destroy_inode(struct inode *inode) { call_rcu(&inode->i_rcu, bdev_i_callback); } |
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static void init_once(void *foo) |
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{ struct bdev_inode *ei = (struct bdev_inode *) foo; struct block_device *bdev = &ei->bdev; |
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memset(bdev, 0, sizeof(*bdev)); mutex_init(&bdev->bd_mutex); |
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INIT_LIST_HEAD(&bdev->bd_inodes); INIT_LIST_HEAD(&bdev->bd_list); |
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#ifdef CONFIG_SYSFS INIT_LIST_HEAD(&bdev->bd_holder_disks); #endif |
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inode_init_once(&ei->vfs_inode); |
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/* Initialize mutex for freeze. */ mutex_init(&bdev->bd_fsfreeze_mutex); |
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} static inline void __bd_forget(struct inode *inode) { list_del_init(&inode->i_devices); inode->i_bdev = NULL; inode->i_mapping = &inode->i_data; } |
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static void bdev_evict_inode(struct inode *inode) |
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{ struct block_device *bdev = &BDEV_I(inode)->bdev; struct list_head *p; |
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truncate_inode_pages(&inode->i_data, 0); invalidate_inode_buffers(inode); /* is it needed here? */ end_writeback(inode); |
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spin_lock(&bdev_lock); while ( (p = bdev->bd_inodes.next) != &bdev->bd_inodes ) { __bd_forget(list_entry(p, struct inode, i_devices)); } list_del_init(&bdev->bd_list); spin_unlock(&bdev_lock); } |
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static const struct super_operations bdev_sops = { |
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.statfs = simple_statfs, .alloc_inode = bdev_alloc_inode, .destroy_inode = bdev_destroy_inode, .drop_inode = generic_delete_inode, |
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.evict_inode = bdev_evict_inode, |
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}; |
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static struct dentry *bd_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) |
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{ |
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return mount_pseudo(fs_type, "bdev:", &bdev_sops, NULL, 0x62646576); |
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} static struct file_system_type bd_type = { .name = "bdev", |
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.mount = bd_mount, |
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.kill_sb = kill_anon_super, }; |
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static struct super_block *blockdev_superblock __read_mostly; |
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void __init bdev_cache_init(void) { int err; |
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struct vfsmount *bd_mnt; |
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bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
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0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| SLAB_MEM_SPREAD|SLAB_PANIC), |
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init_once); |
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err = register_filesystem(&bd_type); if (err) panic("Cannot register bdev pseudo-fs"); bd_mnt = kern_mount(&bd_type); |
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if (IS_ERR(bd_mnt)) panic("Cannot create bdev pseudo-fs"); |
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/* * This vfsmount structure is only used to obtain the * blockdev_superblock, so tell kmemleak not to report it. */ kmemleak_not_leak(bd_mnt); |
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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 LIST_HEAD(all_bdevs); struct block_device *bdget(dev_t dev) { struct block_device *bdev; struct inode *inode; |
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inode = iget5_locked(blockdev_superblock, hash(dev), |
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bdev_test, bdev_set, &dev); if (!inode) return NULL; bdev = &BDEV_I(inode)->bdev; if (inode->i_state & I_NEW) { bdev->bd_contains = NULL; |
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bdev->bd_super = NULL; |
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bdev->bd_inode = inode; bdev->bd_block_size = (1 << inode->i_blkbits); bdev->bd_part_count = 0; bdev->bd_invalidated = 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); inode->i_data.backing_dev_info = &default_backing_dev_info; spin_lock(&bdev_lock); list_add(&bdev->bd_list, &all_bdevs); spin_unlock(&bdev_lock); unlock_new_inode(inode); } return bdev; } EXPORT_SYMBOL(bdget); |
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/** * 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) { |
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ihold(bdev->bd_inode); |
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return bdev; } |
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long nr_blockdev_pages(void) { |
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struct block_device *bdev; |
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long ret = 0; spin_lock(&bdev_lock); |
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list_for_each_entry(bdev, &all_bdevs, bd_list) { |
1da177e4c
|
567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 |
ret += bdev->bd_inode->i_mapping->nrpages; } spin_unlock(&bdev_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; |
09d967c6f
|
583 |
|
1da177e4c
|
584 585 |
spin_lock(&bdev_lock); bdev = inode->i_bdev; |
09d967c6f
|
586 |
if (bdev) { |
7de9c6ee3
|
587 |
ihold(bdev->bd_inode); |
1da177e4c
|
588 589 590 591 |
spin_unlock(&bdev_lock); return bdev; } spin_unlock(&bdev_lock); |
09d967c6f
|
592 |
|
1da177e4c
|
593 594 595 |
bdev = bdget(inode->i_rdev); if (bdev) { spin_lock(&bdev_lock); |
09d967c6f
|
596 597 |
if (!inode->i_bdev) { /* |
7de9c6ee3
|
598 |
* We take an additional reference to bd_inode, |
09d967c6f
|
599 600 601 602 |
* and it's released in clear_inode() of inode. * So, we can access it via ->i_mapping always * without igrab(). */ |
7de9c6ee3
|
603 |
ihold(bdev->bd_inode); |
09d967c6f
|
604 605 606 607 |
inode->i_bdev = bdev; inode->i_mapping = bdev->bd_inode->i_mapping; list_add(&inode->i_devices, &bdev->bd_inodes); } |
1da177e4c
|
608 609 610 611 |
spin_unlock(&bdev_lock); } return bdev; } |
f47ec3f28
|
612 613 614 615 |
static inline int sb_is_blkdev_sb(struct super_block *sb) { return sb == blockdev_superblock; } |
1da177e4c
|
616 617 618 619 |
/* Call when you free inode */ void bd_forget(struct inode *inode) { |
09d967c6f
|
620 |
struct block_device *bdev = NULL; |
1da177e4c
|
621 |
spin_lock(&bdev_lock); |
09d967c6f
|
622 |
if (inode->i_bdev) { |
c2acf7b90
|
623 |
if (!sb_is_blkdev_sb(inode->i_sb)) |
09d967c6f
|
624 |
bdev = inode->i_bdev; |
1da177e4c
|
625 |
__bd_forget(inode); |
09d967c6f
|
626 |
} |
1da177e4c
|
627 |
spin_unlock(&bdev_lock); |
09d967c6f
|
628 629 630 |
if (bdev) iput(bdev->bd_inode); |
1da177e4c
|
631 |
} |
1a3cbbc5a
|
632 633 634 635 636 637 |
/** * 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 * |
25985edce
|
638 |
* Test whether @bdev can be claimed by @holder. |
1a3cbbc5a
|
639 640 641 642 643 644 645 646 647 |
* * 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) |
1da177e4c
|
648 |
{ |
1da177e4c
|
649 |
if (bdev->bd_holder == holder) |
1a3cbbc5a
|
650 |
return true; /* already a holder */ |
1da177e4c
|
651 |
else if (bdev->bd_holder != NULL) |
1a3cbbc5a
|
652 |
return false; /* held by someone else */ |
1da177e4c
|
653 |
else if (bdev->bd_contains == bdev) |
1a3cbbc5a
|
654 |
return true; /* is a whole device which isn't held */ |
1da177e4c
|
655 |
|
e525fd89d
|
656 |
else if (whole->bd_holder == bd_may_claim) |
1a3cbbc5a
|
657 658 659 |
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 */ |
1da177e4c
|
660 |
else |
1a3cbbc5a
|
661 662 663 664 |
return true; /* is a partition of an un-held device */ } /** |
6b4517a79
|
665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 |
* bd_prepare_to_claim - prepare to claim a block device * @bdev: block device of interest * @whole: the whole device containing @bdev, may equal @bdev * @holder: holder trying to claim @bdev * * Prepare to claim @bdev. This function fails if @bdev is already * claimed by another holder and waits if another claiming is in * progress. This function doesn't actually claim. On successful * return, the caller has ownership of bd_claiming and bd_holder[s]. * * CONTEXT: * spin_lock(&bdev_lock). Might release bdev_lock, sleep and regrab * it multiple times. * * RETURNS: * 0 if @bdev can be claimed, -EBUSY otherwise. */ static int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole, void *holder) { retry: /* if someone else claimed, fail */ if (!bd_may_claim(bdev, whole, holder)) return -EBUSY; |
e75aa8589
|
689 690 |
/* if claiming is already in progress, wait for it to finish */ if (whole->bd_claiming) { |
6b4517a79
|
691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 |
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); spin_lock(&bdev_lock); goto retry; } /* yay, all mine */ return 0; } /** * bd_start_claiming - start claiming a block device * @bdev: block device of interest * @holder: holder trying to claim @bdev * * @bdev is about to be opened exclusively. Check @bdev can be opened * exclusively and mark that an exclusive open is in progress. Each * successful call to this function must be matched with a call to |
b0018361c
|
714 715 716 717 718 719 720 |
* either bd_finish_claiming() or bd_abort_claiming() (which do not * fail). * * This function is used to gain exclusive access to the block device * without actually causing other exclusive open attempts to fail. It * should be used when the open sequence itself requires exclusive * access but may subsequently fail. |
6b4517a79
|
721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 |
* * CONTEXT: * Might sleep. * * RETURNS: * Pointer to the block device containing @bdev on success, ERR_PTR() * value on failure. */ static struct block_device *bd_start_claiming(struct block_device *bdev, void *holder) { struct gendisk *disk; struct block_device *whole; int partno, err; might_sleep(); /* * @bdev might not have been initialized properly yet, look up * and grab the outer block device the hard way. */ disk = get_gendisk(bdev->bd_dev, &partno); if (!disk) return ERR_PTR(-ENXIO); |
d4c208b86
|
745 746 747 748 749 750 751 752 753 754 755 756 |
/* * Normally, @bdev should equal what's returned from bdget_disk() * if partno is 0; however, some drivers (floppy) use multiple * bdev's for the same physical device and @bdev may be one of the * aliases. Keep @bdev if partno is 0. This means claimer * tracking is broken for those devices but it has always been that * way. */ if (partno) whole = bdget_disk(disk, 0); else whole = bdgrab(bdev); |
cf3425707
|
757 |
module_put(disk->fops->owner); |
6b4517a79
|
758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 |
put_disk(disk); if (!whole) return ERR_PTR(-ENOMEM); /* prepare to claim, if successful, mark claiming in progress */ spin_lock(&bdev_lock); err = bd_prepare_to_claim(bdev, whole, holder); if (err == 0) { whole->bd_claiming = holder; spin_unlock(&bdev_lock); return whole; } else { spin_unlock(&bdev_lock); bdput(whole); return ERR_PTR(err); } } |
641dc636b
|
776 |
#ifdef CONFIG_SYSFS |
49731baa4
|
777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 |
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; } |
4d7dd8fd9
|
793 |
static int add_symlink(struct kobject *from, struct kobject *to) |
641dc636b
|
794 |
{ |
4d7dd8fd9
|
795 |
return sysfs_create_link(from, to, kobject_name(to)); |
641dc636b
|
796 797 798 799 |
} static void del_symlink(struct kobject *from, struct kobject *to) { |
641dc636b
|
800 801 |
sysfs_remove_link(from, kobject_name(to)); } |
641dc636b
|
802 |
/** |
e09b457bd
|
803 804 805 |
* bd_link_disk_holder - create symlinks between holding disk and slave bdev * @bdev: the claimed slave bdev * @disk: the holding disk |
df6c0cd9a
|
806 |
* |
49731baa4
|
807 808 |
* DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. * |
e09b457bd
|
809 |
* This functions creates the following sysfs symlinks. |
641dc636b
|
810 |
* |
e09b457bd
|
811 812 |
* - from "slaves" directory of the holder @disk to the claimed @bdev * - from "holders" directory of the @bdev to the holder @disk |
641dc636b
|
813 |
* |
e09b457bd
|
814 815 |
* For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is * passed to bd_link_disk_holder(), then: |
641dc636b
|
816 |
* |
e09b457bd
|
817 818 |
* /sys/block/dm-0/slaves/sda --> /sys/block/sda * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 |
641dc636b
|
819 |
* |
e09b457bd
|
820 821 822 |
* 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. |
641dc636b
|
823 |
* |
e09b457bd
|
824 825 |
* CONTEXT: * Might sleep. |
641dc636b
|
826 |
* |
e09b457bd
|
827 828 |
* RETURNS: * 0 on success, -errno on failure. |
641dc636b
|
829 |
*/ |
e09b457bd
|
830 |
int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) |
641dc636b
|
831 |
{ |
49731baa4
|
832 |
struct bd_holder_disk *holder; |
e09b457bd
|
833 |
int ret = 0; |
641dc636b
|
834 |
|
2e7b651df
|
835 |
mutex_lock(&bdev->bd_mutex); |
df6c0cd9a
|
836 |
|
49731baa4
|
837 |
WARN_ON_ONCE(!bdev->bd_holder); |
4e91672c7
|
838 |
|
e09b457bd
|
839 840 841 |
/* FIXME: remove the following once add_disk() handles errors */ if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir)) goto out_unlock; |
4e91672c7
|
842 |
|
49731baa4
|
843 844 845 |
holder = bd_find_holder_disk(bdev, disk); if (holder) { holder->refcnt++; |
e09b457bd
|
846 |
goto out_unlock; |
49731baa4
|
847 |
} |
641dc636b
|
848 |
|
49731baa4
|
849 850 851 |
holder = kzalloc(sizeof(*holder), GFP_KERNEL); if (!holder) { ret = -ENOMEM; |
e09b457bd
|
852 853 |
goto out_unlock; } |
641dc636b
|
854 |
|
49731baa4
|
855 856 857 858 859 860 861 862 863 864 865 |
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; |
e7407d161
|
866 867 868 869 870 |
/* * bdev could be deleted beneath us which would implicitly destroy * the holder directory. Hold on to it. */ kobject_get(bdev->bd_part->holder_dir); |
49731baa4
|
871 872 873 874 875 876 877 878 |
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); |
e09b457bd
|
879 |
out_unlock: |
b4cf1b72e
|
880 |
mutex_unlock(&bdev->bd_mutex); |
e09b457bd
|
881 |
return ret; |
641dc636b
|
882 |
} |
e09b457bd
|
883 |
EXPORT_SYMBOL_GPL(bd_link_disk_holder); |
641dc636b
|
884 |
|
49731baa4
|
885 886 887 888 889 890 891 892 893 894 895 |
/** * 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) |
641dc636b
|
896 |
{ |
49731baa4
|
897 |
struct bd_holder_disk *holder; |
641dc636b
|
898 |
|
49731baa4
|
899 |
mutex_lock(&bdev->bd_mutex); |
641dc636b
|
900 |
|
49731baa4
|
901 902 903 904 905 906 |
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); |
e7407d161
|
907 |
kobject_put(bdev->bd_part->holder_dir); |
49731baa4
|
908 909 910 911 912 |
list_del_init(&holder->list); kfree(holder); } mutex_unlock(&bdev->bd_mutex); |
1da177e4c
|
913 |
} |
49731baa4
|
914 |
EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); |
641dc636b
|
915 |
#endif |
1da177e4c
|
916 |
|
0c002c2f7
|
917 |
/** |
56ade44b4
|
918 919 920 |
* flush_disk - invalidates all buffer-cache entries on a disk * * @bdev: struct block device to be flushed |
e6eb5ce1b
|
921 |
* @kill_dirty: flag to guide handling of dirty inodes |
56ade44b4
|
922 923 924 925 926 |
* * Invalidates all buffer-cache entries on a disk. It should be called * when a disk has been changed -- either by a media change or online * resize. */ |
93b270f76
|
927 |
static void flush_disk(struct block_device *bdev, bool kill_dirty) |
56ade44b4
|
928 |
{ |
93b270f76
|
929 |
if (__invalidate_device(bdev, kill_dirty)) { |
56ade44b4
|
930 931 932 933 934 935 936 937 938 939 940 |
char name[BDEVNAME_SIZE] = ""; if (bdev->bd_disk) disk_name(bdev->bd_disk, 0, name); printk(KERN_WARNING "VFS: busy inodes on changed media or " "resized disk %s ", name); } if (!bdev->bd_disk) return; |
d27769ec3
|
941 |
if (disk_part_scan_enabled(bdev->bd_disk)) |
56ade44b4
|
942 943 944 945 |
bdev->bd_invalidated = 1; } /** |
57d1b5366
|
946 |
* check_disk_size_change - checks for disk size change and adjusts bdev size. |
c3279d145
|
947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 |
* @disk: struct gendisk to check * @bdev: struct bdev to adjust. * * This routine checks to see if the bdev size does not match the disk size * and adjusts it if it differs. */ void check_disk_size_change(struct gendisk *disk, struct block_device *bdev) { loff_t disk_size, bdev_size; disk_size = (loff_t)get_capacity(disk) << 9; bdev_size = i_size_read(bdev->bd_inode); if (disk_size != bdev_size) { char name[BDEVNAME_SIZE]; disk_name(disk, 0, name); printk(KERN_INFO "%s: detected capacity change from %lld to %lld ", name, bdev_size, disk_size); i_size_write(bdev->bd_inode, disk_size); |
93b270f76
|
968 |
flush_disk(bdev, false); |
c3279d145
|
969 970 971 972 973 |
} } EXPORT_SYMBOL(check_disk_size_change); /** |
57d1b5366
|
974 |
* revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back |
0c002c2f7
|
975 976 977 978 979 980 981 982 |
* @disk: struct gendisk to be revalidated * * This routine is a wrapper for lower-level driver's revalidate_disk * call-backs. It is used to do common pre and post operations needed * for all revalidate_disk operations. */ int revalidate_disk(struct gendisk *disk) { |
c3279d145
|
983 |
struct block_device *bdev; |
0c002c2f7
|
984 985 986 987 |
int ret = 0; if (disk->fops->revalidate_disk) ret = disk->fops->revalidate_disk(disk); |
c3279d145
|
988 989 990 991 992 993 994 995 |
bdev = bdget_disk(disk, 0); if (!bdev) return ret; mutex_lock(&bdev->bd_mutex); check_disk_size_change(disk, bdev); mutex_unlock(&bdev->bd_mutex); bdput(bdev); |
0c002c2f7
|
996 997 998 |
return ret; } EXPORT_SYMBOL(revalidate_disk); |
1da177e4c
|
999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 |
/* * This routine checks whether a removable media has been changed, * and invalidates all buffer-cache-entries in that case. This * is a relatively slow routine, so we have to try to minimize using * it. Thus it is called only upon a 'mount' or 'open'. This * is the best way of combining speed and utility, I think. * People changing diskettes in the middle of an operation deserve * to lose :-) */ int check_disk_change(struct block_device *bdev) { struct gendisk *disk = bdev->bd_disk; |
83d5cde47
|
1011 |
const struct block_device_operations *bdops = disk->fops; |
77ea887e4
|
1012 |
unsigned int events; |
1da177e4c
|
1013 |
|
77ea887e4
|
1014 1015 1016 |
events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST); if (!(events & DISK_EVENT_MEDIA_CHANGE)) |
1da177e4c
|
1017 |
return 0; |
93b270f76
|
1018 |
flush_disk(bdev, true); |
1da177e4c
|
1019 1020 |
if (bdops->revalidate_disk) bdops->revalidate_disk(bdev->bd_disk); |
1da177e4c
|
1021 1022 1023 1024 1025 1026 1027 |
return 1; } EXPORT_SYMBOL(check_disk_change); void bd_set_size(struct block_device *bdev, loff_t size) { |
e1defc4ff
|
1028 |
unsigned bsize = bdev_logical_block_size(bdev); |
1da177e4c
|
1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 |
bdev->bd_inode->i_size = size; while (bsize < PAGE_CACHE_SIZE) { if (size & bsize) break; bsize <<= 1; } bdev->bd_block_size = bsize; bdev->bd_inode->i_blkbits = blksize_bits(bsize); } EXPORT_SYMBOL(bd_set_size); |
9a1c35427
|
1040 |
static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); |
37be41241
|
1041 |
|
6d740cd5b
|
1042 1043 1044 1045 1046 1047 |
/* * bd_mutex locking: * * mutex_lock(part->bd_mutex) * mutex_lock_nested(whole->bd_mutex, 1) */ |
572c48921
|
1048 |
static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part) |
1da177e4c
|
1049 |
{ |
1da177e4c
|
1050 |
struct gendisk *disk; |
523e1d399
|
1051 |
struct module *owner; |
7db9cfd38
|
1052 |
int ret; |
cf771cb5a
|
1053 |
int partno; |
fe6e9c1f2
|
1054 |
int perm = 0; |
572c48921
|
1055 |
if (mode & FMODE_READ) |
fe6e9c1f2
|
1056 |
perm |= MAY_READ; |
572c48921
|
1057 |
if (mode & FMODE_WRITE) |
fe6e9c1f2
|
1058 1059 1060 1061 |
perm |= MAY_WRITE; /* * hooks: /n/, see "layering violations". */ |
b7300b78d
|
1062 1063 1064 1065 1066 1067 |
if (!for_part) { ret = devcgroup_inode_permission(bdev->bd_inode, perm); if (ret != 0) { bdput(bdev); return ret; } |
826660203
|
1068 |
} |
7db9cfd38
|
1069 |
|
d3374825c
|
1070 |
restart: |
0762b8bde
|
1071 |
|
89f97496e
|
1072 |
ret = -ENXIO; |
cf771cb5a
|
1073 |
disk = get_gendisk(bdev->bd_dev, &partno); |
0762b8bde
|
1074 |
if (!disk) |
6e9624b8c
|
1075 |
goto out; |
523e1d399
|
1076 |
owner = disk->fops->owner; |
1da177e4c
|
1077 |
|
69e02c59a
|
1078 |
disk_block_events(disk); |
6796bf54a
|
1079 |
mutex_lock_nested(&bdev->bd_mutex, for_part); |
1da177e4c
|
1080 1081 1082 |
if (!bdev->bd_openers) { bdev->bd_disk = disk; bdev->bd_contains = bdev; |
cf771cb5a
|
1083 |
if (!partno) { |
1da177e4c
|
1084 |
struct backing_dev_info *bdi; |
89f97496e
|
1085 1086 1087 1088 1089 |
ret = -ENXIO; bdev->bd_part = disk_get_part(disk, partno); if (!bdev->bd_part) goto out_clear; |
1196f8b81
|
1090 |
ret = 0; |
1da177e4c
|
1091 |
if (disk->fops->open) { |
572c48921
|
1092 |
ret = disk->fops->open(bdev, mode); |
d3374825c
|
1093 1094 1095 1096 1097 1098 1099 |
if (ret == -ERESTARTSYS) { /* Lost a race with 'disk' being * deleted, try again. * See md.c */ disk_put_part(bdev->bd_part); bdev->bd_part = NULL; |
d3374825c
|
1100 1101 |
bdev->bd_disk = NULL; mutex_unlock(&bdev->bd_mutex); |
69e02c59a
|
1102 |
disk_unblock_events(disk); |
69e02c59a
|
1103 |
put_disk(disk); |
523e1d399
|
1104 |
module_put(owner); |
d3374825c
|
1105 1106 |
goto restart; } |
1da177e4c
|
1107 |
} |
7e69723fe
|
1108 1109 1110 1111 1112 1113 1114 1115 |
if (!ret && !bdev->bd_openers) { bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); bdi = blk_get_backing_dev_info(bdev); if (bdi == NULL) bdi = &default_backing_dev_info; bdev_inode_switch_bdi(bdev->bd_inode, bdi); } |
1196f8b81
|
1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 |
/* * 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 (bdev->bd_invalidated && (!ret || ret == -ENOMEDIUM)) rescan_partitions(disk, bdev); if (ret) goto out_clear; |
1da177e4c
|
1126 |
} else { |
1da177e4c
|
1127 1128 1129 1130 |
struct block_device *whole; whole = bdget_disk(disk, 0); ret = -ENOMEM; if (!whole) |
0762b8bde
|
1131 |
goto out_clear; |
37be41241
|
1132 |
BUG_ON(for_part); |
572c48921
|
1133 |
ret = __blkdev_get(whole, mode, 1); |
1da177e4c
|
1134 |
if (ret) |
0762b8bde
|
1135 |
goto out_clear; |
1da177e4c
|
1136 |
bdev->bd_contains = whole; |
a5491e0c7
|
1137 1138 |
bdev_inode_switch_bdi(bdev->bd_inode, whole->bd_inode->i_data.backing_dev_info); |
89f97496e
|
1139 |
bdev->bd_part = disk_get_part(disk, partno); |
e71bf0d0e
|
1140 |
if (!(disk->flags & GENHD_FL_UP) || |
89f97496e
|
1141 |
!bdev->bd_part || !bdev->bd_part->nr_sects) { |
1da177e4c
|
1142 |
ret = -ENXIO; |
0762b8bde
|
1143 |
goto out_clear; |
1da177e4c
|
1144 |
} |
89f97496e
|
1145 |
bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9); |
1da177e4c
|
1146 1147 |
} } else { |
1da177e4c
|
1148 |
if (bdev->bd_contains == bdev) { |
1196f8b81
|
1149 1150 |
ret = 0; if (bdev->bd_disk->fops->open) |
572c48921
|
1151 |
ret = bdev->bd_disk->fops->open(bdev, mode); |
1196f8b81
|
1152 1153 |
/* the same as first opener case, read comment there */ if (bdev->bd_invalidated && (!ret || ret == -ENOMEDIUM)) |
1da177e4c
|
1154 |
rescan_partitions(bdev->bd_disk, bdev); |
1196f8b81
|
1155 1156 |
if (ret) goto out_unlock_bdev; |
1da177e4c
|
1157 |
} |
69e02c59a
|
1158 |
/* only one opener holds refs to the module and disk */ |
69e02c59a
|
1159 |
put_disk(disk); |
523e1d399
|
1160 |
module_put(owner); |
1da177e4c
|
1161 1162 |
} bdev->bd_openers++; |
37be41241
|
1163 1164 |
if (for_part) bdev->bd_part_count++; |
c039e3134
|
1165 |
mutex_unlock(&bdev->bd_mutex); |
69e02c59a
|
1166 |
disk_unblock_events(disk); |
1da177e4c
|
1167 |
return 0; |
0762b8bde
|
1168 |
out_clear: |
89f97496e
|
1169 |
disk_put_part(bdev->bd_part); |
1da177e4c
|
1170 |
bdev->bd_disk = NULL; |
0762b8bde
|
1171 |
bdev->bd_part = NULL; |
a5491e0c7
|
1172 |
bdev_inode_switch_bdi(bdev->bd_inode, &default_backing_dev_info); |
1da177e4c
|
1173 |
if (bdev != bdev->bd_contains) |
572c48921
|
1174 |
__blkdev_put(bdev->bd_contains, mode, 1); |
1da177e4c
|
1175 |
bdev->bd_contains = NULL; |
0762b8bde
|
1176 |
out_unlock_bdev: |
c039e3134
|
1177 |
mutex_unlock(&bdev->bd_mutex); |
69e02c59a
|
1178 |
disk_unblock_events(disk); |
0762b8bde
|
1179 |
put_disk(disk); |
523e1d399
|
1180 |
module_put(owner); |
4345caba3
|
1181 |
out: |
0762b8bde
|
1182 |
bdput(bdev); |
1da177e4c
|
1183 1184 |
return ret; } |
d4d776299
|
1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 |
/** * 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. */ |
e525fd89d
|
1204 |
int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) |
1da177e4c
|
1205 |
{ |
e525fd89d
|
1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 |
struct block_device *whole = NULL; int res; WARN_ON_ONCE((mode & FMODE_EXCL) && !holder); if ((mode & FMODE_EXCL) && holder) { whole = bd_start_claiming(bdev, holder); if (IS_ERR(whole)) { bdput(bdev); return PTR_ERR(whole); } } res = __blkdev_get(bdev, mode, 0); if (whole) { |
d4dc210f6
|
1222 |
struct gendisk *disk = whole->bd_disk; |
6a027eff6
|
1223 |
/* finish claiming */ |
77ea887e4
|
1224 |
mutex_lock(&bdev->bd_mutex); |
6a027eff6
|
1225 |
spin_lock(&bdev_lock); |
77ea887e4
|
1226 |
if (!res) { |
6a027eff6
|
1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 |
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; } /* tell others that we're done */ BUG_ON(whole->bd_claiming != holder); whole->bd_claiming = NULL; wake_up_bit(&whole->bd_claiming, 0); spin_unlock(&bdev_lock); |
77ea887e4
|
1246 1247 |
/* |
d4dc210f6
|
1248 1249 1250 1251 1252 |
* 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(). |
77ea887e4
|
1253 |
*/ |
4c49ff3fe
|
1254 1255 |
if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder && (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) { |
77ea887e4
|
1256 |
bdev->bd_write_holder = true; |
d4dc210f6
|
1257 |
disk_block_events(disk); |
77ea887e4
|
1258 1259 1260 |
} mutex_unlock(&bdev->bd_mutex); |
6a027eff6
|
1261 |
bdput(whole); |
e525fd89d
|
1262 1263 1264 |
} return res; |
37be41241
|
1265 |
} |
1da177e4c
|
1266 |
EXPORT_SYMBOL(blkdev_get); |
d4d776299
|
1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 |
/** * 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); |
e51900f7d
|
1297 1298 1299 1300 |
if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) { blkdev_put(bdev, mode); return ERR_PTR(-EACCES); } |
d4d776299
|
1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 |
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); |
1da177e4c
|
1343 1344 1345 |
static int blkdev_open(struct inode * inode, struct file * filp) { struct block_device *bdev; |
1da177e4c
|
1346 1347 1348 1349 1350 1351 1352 1353 |
/* * 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; |
572c48921
|
1354 1355 1356 1357 1358 1359 |
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; |
1da177e4c
|
1360 |
bdev = bd_acquire(inode); |
6a2aae06c
|
1361 1362 |
if (bdev == NULL) return -ENOMEM; |
1da177e4c
|
1363 |
|
572c48921
|
1364 |
filp->f_mapping = bdev->bd_inode->i_mapping; |
e525fd89d
|
1365 |
return blkdev_get(bdev, filp->f_mode, filp); |
1da177e4c
|
1366 |
} |
9a1c35427
|
1367 |
static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) |
2e7b651df
|
1368 1369 |
{ int ret = 0; |
2e7b651df
|
1370 |
struct gendisk *disk = bdev->bd_disk; |
37be41241
|
1371 |
struct block_device *victim = NULL; |
2e7b651df
|
1372 |
|
6796bf54a
|
1373 |
mutex_lock_nested(&bdev->bd_mutex, for_part); |
37be41241
|
1374 1375 |
if (for_part) bdev->bd_part_count--; |
2e7b651df
|
1376 |
if (!--bdev->bd_openers) { |
6a027eff6
|
1377 |
WARN_ON_ONCE(bdev->bd_holders); |
2e7b651df
|
1378 1379 |
sync_blockdev(bdev); kill_bdev(bdev); |
94007751b
|
1380 1381 1382 1383 1384 |
/* ->release can cause the old bdi to disappear, * so must switch it out first */ bdev_inode_switch_bdi(bdev->bd_inode, &default_backing_dev_info); |
2e7b651df
|
1385 1386 1387 |
} if (bdev->bd_contains == bdev) { if (disk->fops->release) |
9a1c35427
|
1388 |
ret = disk->fops->release(disk, mode); |
2e7b651df
|
1389 1390 1391 |
} if (!bdev->bd_openers) { struct module *owner = disk->fops->owner; |
0762b8bde
|
1392 1393 |
disk_put_part(bdev->bd_part); bdev->bd_part = NULL; |
2e7b651df
|
1394 |
bdev->bd_disk = NULL; |
37be41241
|
1395 1396 |
if (bdev != bdev->bd_contains) victim = bdev->bd_contains; |
2e7b651df
|
1397 |
bdev->bd_contains = NULL; |
523e1d399
|
1398 1399 1400 |
put_disk(disk); module_put(owner); |
2e7b651df
|
1401 |
} |
2e7b651df
|
1402 1403 |
mutex_unlock(&bdev->bd_mutex); bdput(bdev); |
37be41241
|
1404 |
if (victim) |
9a1c35427
|
1405 |
__blkdev_put(victim, mode, 1); |
2e7b651df
|
1406 1407 |
return ret; } |
9a1c35427
|
1408 |
int blkdev_put(struct block_device *bdev, fmode_t mode) |
37be41241
|
1409 |
{ |
85ef06d1d
|
1410 |
mutex_lock(&bdev->bd_mutex); |
e525fd89d
|
1411 |
if (mode & FMODE_EXCL) { |
6a027eff6
|
1412 1413 1414 1415 1416 1417 1418 |
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. */ |
6a027eff6
|
1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 |
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); |
77ea887e4
|
1431 1432 1433 1434 |
/* * If this was the last claim, remove holder link and * unblock evpoll if it was a write holder. */ |
85ef06d1d
|
1435 1436 1437 |
if (bdev_free && bdev->bd_write_holder) { disk_unblock_events(bdev->bd_disk); bdev->bd_write_holder = false; |
77ea887e4
|
1438 |
} |
6936217cc
|
1439 |
} |
77ea887e4
|
1440 |
|
85ef06d1d
|
1441 1442 1443 1444 1445 1446 1447 1448 |
/* * 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); |
9a1c35427
|
1449 |
return __blkdev_put(bdev, mode, 0); |
37be41241
|
1450 |
} |
2e7b651df
|
1451 |
EXPORT_SYMBOL(blkdev_put); |
1da177e4c
|
1452 1453 1454 |
static int blkdev_close(struct inode * inode, struct file * filp) { struct block_device *bdev = I_BDEV(filp->f_mapping->host); |
e525fd89d
|
1455 |
|
9a1c35427
|
1456 |
return blkdev_put(bdev, filp->f_mode); |
1da177e4c
|
1457 |
} |
bb93e3a52
|
1458 |
static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg) |
1da177e4c
|
1459 |
{ |
56b26add0
|
1460 1461 |
struct block_device *bdev = I_BDEV(file->f_mapping->host); fmode_t mode = file->f_mode; |
fd4ce1acd
|
1462 1463 1464 1465 1466 |
/* * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have * to updated it before every ioctl. */ |
56b26add0
|
1467 |
if (file->f_flags & O_NDELAY) |
fd4ce1acd
|
1468 1469 1470 |
mode |= FMODE_NDELAY; else mode &= ~FMODE_NDELAY; |
56b26add0
|
1471 |
return blkdev_ioctl(bdev, mode, cmd, arg); |
1da177e4c
|
1472 |
} |
87d8fe1ee
|
1473 |
/* |
eef993806
|
1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 |
* 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_aio_write(struct kiocb *iocb, const struct iovec *iov, unsigned long nr_segs, loff_t pos) { struct file *file = iocb->ki_filp; ssize_t ret; BUG_ON(iocb->ki_pos != pos); ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos); if (ret > 0 || ret == -EIOCBQUEUED) { ssize_t err; err = generic_write_sync(file, pos, ret); if (err < 0 && ret > 0) ret = err; } return ret; } EXPORT_SYMBOL_GPL(blkdev_aio_write); /* |
87d8fe1ee
|
1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 |
* 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); } |
4c54ac62d
|
1513 |
static const struct address_space_operations def_blk_aops = { |
1da177e4c
|
1514 1515 |
.readpage = blkdev_readpage, .writepage = blkdev_writepage, |
6272b5a58
|
1516 1517 |
.write_begin = blkdev_write_begin, .write_end = blkdev_write_end, |
1da177e4c
|
1518 |
.writepages = generic_writepages, |
87d8fe1ee
|
1519 |
.releasepage = blkdev_releasepage, |
1da177e4c
|
1520 1521 |
.direct_IO = blkdev_direct_IO, }; |
4b6f5d20b
|
1522 |
const struct file_operations def_blk_fops = { |
1da177e4c
|
1523 1524 1525 |
.open = blkdev_open, .release = blkdev_close, .llseek = block_llseek, |
543ade1fc
|
1526 1527 |
.read = do_sync_read, .write = do_sync_write, |
1da177e4c
|
1528 |
.aio_read = generic_file_aio_read, |
eef993806
|
1529 |
.aio_write = blkdev_aio_write, |
1da177e4c
|
1530 |
.mmap = generic_file_mmap, |
b1dd3b284
|
1531 |
.fsync = blkdev_fsync, |
bb93e3a52
|
1532 |
.unlocked_ioctl = block_ioctl, |
1da177e4c
|
1533 1534 1535 |
#ifdef CONFIG_COMPAT .compat_ioctl = compat_blkdev_ioctl, #endif |
7f9c51f0d
|
1536 1537 |
.splice_read = generic_file_splice_read, .splice_write = generic_file_splice_write, |
1da177e4c
|
1538 1539 1540 1541 1542 1543 1544 |
}; int ioctl_by_bdev(struct block_device *bdev, unsigned cmd, unsigned long arg) { int res; mm_segment_t old_fs = get_fs(); set_fs(KERNEL_DS); |
56b26add0
|
1545 |
res = blkdev_ioctl(bdev, 0, cmd, arg); |
1da177e4c
|
1546 1547 1548 1549 1550 1551 1552 1553 |
set_fs(old_fs); return res; } EXPORT_SYMBOL(ioctl_by_bdev); /** * lookup_bdev - lookup a struct block_device by name |
94e2959e7
|
1554 |
* @pathname: special file representing the block device |
1da177e4c
|
1555 |
* |
57d1b5366
|
1556 |
* Get a reference to the blockdevice at @pathname in the current |
1da177e4c
|
1557 1558 1559 |
* namespace if possible and return it. Return ERR_PTR(error) * otherwise. */ |
421748ecd
|
1560 |
struct block_device *lookup_bdev(const char *pathname) |
1da177e4c
|
1561 1562 1563 |
{ struct block_device *bdev; struct inode *inode; |
421748ecd
|
1564 |
struct path path; |
1da177e4c
|
1565 |
int error; |
421748ecd
|
1566 |
if (!pathname || !*pathname) |
1da177e4c
|
1567 |
return ERR_PTR(-EINVAL); |
421748ecd
|
1568 |
error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
1da177e4c
|
1569 1570 |
if (error) return ERR_PTR(error); |
421748ecd
|
1571 |
inode = path.dentry->d_inode; |
1da177e4c
|
1572 1573 1574 1575 |
error = -ENOTBLK; if (!S_ISBLK(inode->i_mode)) goto fail; error = -EACCES; |
421748ecd
|
1576 |
if (path.mnt->mnt_flags & MNT_NODEV) |
1da177e4c
|
1577 1578 1579 1580 1581 1582 |
goto fail; error = -ENOMEM; bdev = bd_acquire(inode); if (!bdev) goto fail; out: |
421748ecd
|
1583 |
path_put(&path); |
1da177e4c
|
1584 1585 1586 1587 1588 |
return bdev; fail: bdev = ERR_PTR(error); goto out; } |
d5686b444
|
1589 |
EXPORT_SYMBOL(lookup_bdev); |
1da177e4c
|
1590 |
|
93b270f76
|
1591 |
int __invalidate_device(struct block_device *bdev, bool kill_dirty) |
b71e8a4ce
|
1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 |
{ 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); |
93b270f76
|
1604 |
res = invalidate_inodes(sb, kill_dirty); |
b71e8a4ce
|
1605 1606 |
drop_super(sb); } |
f98393a64
|
1607 |
invalidate_bdev(bdev); |
b71e8a4ce
|
1608 1609 1610 |
return res; } EXPORT_SYMBOL(__invalidate_device); |