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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /ANDROID_3.4.5/fs/block_dev.c
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'ANDROID_3.4.5/fs/block_dev.c')
-rw-r--r--ANDROID_3.4.5/fs/block_dev.c1712
1 files changed, 0 insertions, 1712 deletions
diff --git a/ANDROID_3.4.5/fs/block_dev.c b/ANDROID_3.4.5/fs/block_dev.c
deleted file mode 100644
index ba11c30f..00000000
--- a/ANDROID_3.4.5/fs/block_dev.c
+++ /dev/null
@@ -1,1712 +0,0 @@
-/*
- * linux/fs/block_dev.c
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
- */
-
-#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/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/uio.h>
-#include <linux/namei.h>
-#include <linux/log2.h>
-#include <linux/cleancache.h>
-#include <asm/uaccess.h>
-#include "internal.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);
-}
-
-inline struct block_device *I_BDEV(struct inode *inode)
-{
- return &BDEV_I(inode)->bdev;
-}
-EXPORT_SYMBOL(I_BDEV);
-
-/*
- * 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.
- */
-static void bdev_inode_switch_bdi(struct inode *inode,
- struct backing_dev_info *dst)
-{
- 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);
- spin_lock(&inode->i_lock);
- inode->i_data.backing_dev_info = dst;
- if (inode->i_state & I_DIRTY)
- list_move(&inode->i_wb_list, &dst->wb.b_dirty);
- spin_unlock(&inode->i_lock);
- spin_unlock(&old->wb.list_lock);
- spin_unlock(&dst->wb.list_lock);
-}
-
-sector_t blkdev_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;
-}
-
-/* Kill _all_ buffers and pagecache , dirty or not.. */
-void kill_bdev(struct block_device *bdev)
-{
- struct address_space *mapping = bdev->bd_inode->i_mapping;
-
- if (mapping->nrpages == 0)
- return;
-
- invalidate_bh_lrus();
- truncate_inode_pages(mapping, 0);
-}
-EXPORT_SYMBOL(kill_bdev);
-
-/* 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 == 0)
- return;
-
- 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);
-
-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_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)
-{
- 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)
-{
- if (iblock >= blkdev_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;
-}
-
-static int
-blkdev_get_blocks(struct inode *inode, sector_t iblock,
- struct buffer_head *bh, int create)
-{
- sector_t end_block = blkdev_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;
-
- return __blockdev_direct_IO(rw, iocb, inode, I_BDEV(inode), iov, offset,
- nr_segs, blkdev_get_blocks, NULL, NULL, 0);
-}
-
-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.
- */
-struct super_block *freeze_bdev(struct block_device *bdev)
-{
- struct super_block *sb;
- int error = 0;
-
- mutex_lock(&bdev->bd_fsfreeze_mutex);
- if (++bdev->bd_fsfreeze_count > 1) {
- /*
- * We don't even need to grab a reference - the first call
- * to freeze_bdev grab an active reference and only the last
- * thaw_bdev drops it.
- */
- sb = get_super(bdev);
- drop_super(sb);
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return sb;
- }
-
- sb = get_active_super(bdev);
- if (!sb)
- goto out;
- error = freeze_super(sb);
- if (error) {
- deactivate_super(sb);
- bdev->bd_fsfreeze_count--;
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return ERR_PTR(error);
- }
- deactivate_super(sb);
- out:
- sync_blockdev(bdev);
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return sb; /* thaw_bdev releases s->s_umount */
-}
-EXPORT_SYMBOL(freeze_bdev);
-
-/**
- * thaw_bdev -- unlock filesystem
- * @bdev: blockdevice to unlock
- * @sb: associated superblock
- *
- * Unlocks the filesystem and marks it writeable again after freeze_bdev().
- */
-int thaw_bdev(struct block_device *bdev, struct super_block *sb)
-{
- int error = -EINVAL;
-
- mutex_lock(&bdev->bd_fsfreeze_mutex);
- if (!bdev->bd_fsfreeze_count)
- goto out;
-
- error = 0;
- if (--bdev->bd_fsfreeze_count > 0)
- goto out;
-
- if (!sb)
- goto out;
-
- error = thaw_super(sb);
- if (error) {
- bdev->bd_fsfreeze_count++;
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return error;
- }
-out:
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return 0;
-}
-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 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);
- page_cache_release(page);
-
- return ret;
-}
-
-/*
- * private llseek:
- * for a block special file file->f_path.dentry->d_inode->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 origin)
-{
- struct inode *bd_inode = file->f_mapping->host;
- loff_t size;
- loff_t retval;
-
- mutex_lock(&bd_inode->i_mutex);
- size = i_size_read(bd_inode);
-
- retval = -EINVAL;
- switch (origin) {
- case SEEK_END:
- offset += size;
- break;
- case SEEK_CUR:
- offset += file->f_pos;
- case SEEK_SET:
- break;
- default:
- goto out;
- }
- if (offset >= 0 && offset <= size) {
- if (offset != file->f_pos) {
- file->f_pos = offset;
- }
- retval = offset;
- }
-out:
- mutex_unlock(&bd_inode->i_mutex);
- return retval;
-}
-
-int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
-{
- struct inode *bd_inode = filp->f_mapping->host;
- struct block_device *bdev = I_BDEV(bd_inode);
- int error;
-
- error = filemap_write_and_wait_range(filp->f_mapping, start, end);
- if (error)
- return error;
-
- /*
- * There is no need to serialise calls to blkdev_issue_flush with
- * i_mutex and doing so causes performance issues with concurrent
- * O_SYNC writers to a block device.
- */
- error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL);
- if (error == -EOPNOTSUPP)
- error = 0;
-
- return error;
-}
-EXPORT_SYMBOL(blkdev_fsync);
-
-/*
- * pseudo-fs
- */
-
-static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock);
-static struct kmem_cache * bdev_cachep __read_mostly;
-
-static struct inode *bdev_alloc_inode(struct super_block *sb)
-{
- struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL);
- if (!ei)
- return NULL;
- return &ei->vfs_inode;
-}
-
-static void bdev_i_callback(struct rcu_head *head)
-{
- struct inode *inode = container_of(head, struct inode, i_rcu);
- struct bdev_inode *bdi = BDEV_I(inode);
-
- kmem_cache_free(bdev_cachep, bdi);
-}
-
-static void bdev_destroy_inode(struct inode *inode)
-{
- call_rcu(&inode->i_rcu, bdev_i_callback);
-}
-
-static void init_once(void *foo)
-{
- struct bdev_inode *ei = (struct bdev_inode *) foo;
- struct block_device *bdev = &ei->bdev;
-
- memset(bdev, 0, sizeof(*bdev));
- mutex_init(&bdev->bd_mutex);
- INIT_LIST_HEAD(&bdev->bd_inodes);
- INIT_LIST_HEAD(&bdev->bd_list);
-#ifdef CONFIG_SYSFS
- INIT_LIST_HEAD(&bdev->bd_holder_disks);
-#endif
- inode_init_once(&ei->vfs_inode);
- /* Initialize mutex for freeze. */
- mutex_init(&bdev->bd_fsfreeze_mutex);
-}
-
-static inline void __bd_forget(struct inode *inode)
-{
- list_del_init(&inode->i_devices);
- inode->i_bdev = NULL;
- inode->i_mapping = &inode->i_data;
-}
-
-static void bdev_evict_inode(struct inode *inode)
-{
- struct block_device *bdev = &BDEV_I(inode)->bdev;
- struct list_head *p;
- truncate_inode_pages(&inode->i_data, 0);
- invalidate_inode_buffers(inode); /* is it needed here? */
- end_writeback(inode);
- 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);
-}
-
-static const struct super_operations bdev_sops = {
- .statfs = simple_statfs,
- .alloc_inode = bdev_alloc_inode,
- .destroy_inode = bdev_destroy_inode,
- .drop_inode = generic_delete_inode,
- .evict_inode = bdev_evict_inode,
-};
-
-static struct dentry *bd_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data)
-{
- return mount_pseudo(fs_type, "bdev:", &bdev_sops, NULL, BDEVFS_MAGIC);
-}
-
-static struct file_system_type bd_type = {
- .name = "bdev",
- .mount = bd_mount,
- .kill_sb = kill_anon_super,
-};
-
-static struct super_block *blockdev_superblock __read_mostly;
-
-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_PANIC),
- init_once);
- err = register_filesystem(&bd_type);
- if (err)
- panic("Cannot register bdev pseudo-fs");
- bd_mnt = kern_mount(&bd_type);
- if (IS_ERR(bd_mnt))
- panic("Cannot create bdev pseudo-fs");
- blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */
-}
-
-/*
- * Most likely _very_ bad one - but then it's hardly critical for small
- * /dev and can be fixed when somebody will need really large one.
- * Keep in mind that it will be fed through icache hash function too.
- */
-static inline unsigned long hash(dev_t dev)
-{
- return MAJOR(dev)+MINOR(dev);
-}
-
-static int bdev_test(struct inode *inode, void *data)
-{
- return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data;
-}
-
-static int bdev_set(struct inode *inode, void *data)
-{
- BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data;
- return 0;
-}
-
-static LIST_HEAD(all_bdevs);
-
-struct block_device *bdget(dev_t dev)
-{
- struct block_device *bdev;
- struct inode *inode;
-
- inode = iget5_locked(blockdev_superblock, hash(dev),
- bdev_test, bdev_set, &dev);
-
- if (!inode)
- return NULL;
-
- bdev = &BDEV_I(inode)->bdev;
-
- if (inode->i_state & I_NEW) {
- bdev->bd_contains = NULL;
- bdev->bd_super = NULL;
- 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);
-
-/**
- * bdgrab -- Grab a reference to an already referenced block device
- * @bdev: Block device to grab a reference to.
- */
-struct block_device *bdgrab(struct block_device *bdev)
-{
- ihold(bdev->bd_inode);
- return bdev;
-}
-
-long nr_blockdev_pages(void)
-{
- struct block_device *bdev;
- long ret = 0;
- spin_lock(&bdev_lock);
- list_for_each_entry(bdev, &all_bdevs, bd_list) {
- 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;
-
- spin_lock(&bdev_lock);
- bdev = inode->i_bdev;
- if (bdev) {
- ihold(bdev->bd_inode);
- spin_unlock(&bdev_lock);
- return bdev;
- }
- spin_unlock(&bdev_lock);
-
- bdev = bdget(inode->i_rdev);
- if (bdev) {
- spin_lock(&bdev_lock);
- if (!inode->i_bdev) {
- /*
- * We take an additional reference to bd_inode,
- * and it's released in clear_inode() of inode.
- * So, we can access it via ->i_mapping always
- * without igrab().
- */
- ihold(bdev->bd_inode);
- inode->i_bdev = bdev;
- inode->i_mapping = bdev->bd_inode->i_mapping;
- list_add(&inode->i_devices, &bdev->bd_inodes);
- }
- spin_unlock(&bdev_lock);
- }
- return bdev;
-}
-
-static inline int sb_is_blkdev_sb(struct super_block *sb)
-{
- return sb == blockdev_superblock;
-}
-
-/* Call when you free inode */
-
-void bd_forget(struct inode *inode)
-{
- struct block_device *bdev = NULL;
-
- spin_lock(&bdev_lock);
- if (inode->i_bdev) {
- if (!sb_is_blkdev_sb(inode->i_sb))
- bdev = inode->i_bdev;
- __bd_forget(inode);
- }
- spin_unlock(&bdev_lock);
-
- if (bdev)
- iput(bdev->bd_inode);
-}
-
-/**
- * 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 (bdev->bd_contains == 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 - 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;
-
- /* 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);
- 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
- * 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.
- *
- * 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);
-
- /*
- * 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);
-
- module_put(disk->fops->owner);
- 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);
- }
-}
-
-#ifdef CONFIG_SYSFS
-struct bd_holder_disk {
- struct list_head list;
- struct gendisk *disk;
- int refcnt;
-};
-
-static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev,
- struct gendisk *disk)
-{
- struct bd_holder_disk *holder;
-
- list_for_each_entry(holder, &bdev->bd_holder_disks, list)
- if (holder->disk == disk)
- return holder;
- return NULL;
-}
-
-static int add_symlink(struct kobject *from, struct kobject *to)
-{
- return sysfs_create_link(from, to, kobject_name(to));
-}
-
-static void del_symlink(struct kobject *from, struct kobject *to)
-{
- sysfs_remove_link(from, kobject_name(to));
-}
-
-/**
- * bd_link_disk_holder - create symlinks between holding disk and slave bdev
- * @bdev: the claimed slave bdev
- * @disk: the holding disk
- *
- * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
- *
- * This functions creates the following sysfs symlinks.
- *
- * - from "slaves" directory of the holder @disk to the claimed @bdev
- * - from "holders" directory of the @bdev to the holder @disk
- *
- * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is
- * passed to bd_link_disk_holder(), then:
- *
- * /sys/block/dm-0/slaves/sda --> /sys/block/sda
- * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
- *
- * The caller must have claimed @bdev before calling this function and
- * ensure that both @bdev and @disk are valid during the creation and
- * lifetime of these symlinks.
- *
- * CONTEXT:
- * Might sleep.
- *
- * RETURNS:
- * 0 on success, -errno on failure.
- */
-int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk)
-{
- struct bd_holder_disk *holder;
- int ret = 0;
-
- mutex_lock(&bdev->bd_mutex);
-
- WARN_ON_ONCE(!bdev->bd_holder);
-
- /* FIXME: remove the following once add_disk() handles errors */
- if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir))
- goto out_unlock;
-
- holder = bd_find_holder_disk(bdev, disk);
- if (holder) {
- holder->refcnt++;
- goto out_unlock;
- }
-
- holder = kzalloc(sizeof(*holder), GFP_KERNEL);
- if (!holder) {
- ret = -ENOMEM;
- goto out_unlock;
- }
-
- INIT_LIST_HEAD(&holder->list);
- holder->disk = disk;
- holder->refcnt = 1;
-
- ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
- if (ret)
- goto out_free;
-
- ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj);
- if (ret)
- goto out_del;
- /*
- * bdev could be deleted beneath us which would implicitly destroy
- * the holder directory. Hold on to it.
- */
- kobject_get(bdev->bd_part->holder_dir);
-
- list_add(&holder->list, &bdev->bd_holder_disks);
- goto out_unlock;
-
-out_del:
- del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
-out_free:
- kfree(holder);
-out_unlock:
- mutex_unlock(&bdev->bd_mutex);
- return ret;
-}
-EXPORT_SYMBOL_GPL(bd_link_disk_holder);
-
-/**
- * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder()
- * @bdev: the calimed slave bdev
- * @disk: the holding disk
- *
- * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT.
- *
- * CONTEXT:
- * Might sleep.
- */
-void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk)
-{
- struct bd_holder_disk *holder;
-
- mutex_lock(&bdev->bd_mutex);
-
- holder = bd_find_holder_disk(bdev, disk);
-
- if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) {
- del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj);
- del_symlink(bdev->bd_part->holder_dir,
- &disk_to_dev(disk)->kobj);
- kobject_put(bdev->bd_part->holder_dir);
- list_del_init(&holder->list);
- kfree(holder);
- }
-
- mutex_unlock(&bdev->bd_mutex);
-}
-EXPORT_SYMBOL_GPL(bd_unlink_disk_holder);
-#endif
-
-/**
- * flush_disk - invalidates all buffer-cache entries on a disk
- *
- * @bdev: struct block device to be flushed
- * @kill_dirty: flag to guide handling of dirty inodes
- *
- * 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.
- */
-static void flush_disk(struct block_device *bdev, bool kill_dirty)
-{
- if (__invalidate_device(bdev, kill_dirty)) {
- 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\n", name);
- }
-
- if (!bdev->bd_disk)
- return;
- if (disk_part_scan_enabled(bdev->bd_disk))
- bdev->bd_invalidated = 1;
-}
-
-/**
- * check_disk_size_change - checks for disk size change and adjusts bdev size.
- * @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\n",
- name, bdev_size, disk_size);
- i_size_write(bdev->bd_inode, disk_size);
- flush_disk(bdev, false);
- }
-}
-EXPORT_SYMBOL(check_disk_size_change);
-
-/**
- * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back
- * @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)
-{
- struct block_device *bdev;
- int ret = 0;
-
- if (disk->fops->revalidate_disk)
- ret = disk->fops->revalidate_disk(disk);
-
- 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);
- return ret;
-}
-EXPORT_SYMBOL(revalidate_disk);
-
-/*
- * 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;
- const struct block_device_operations *bdops = disk->fops;
- unsigned int events;
-
- events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE |
- DISK_EVENT_EJECT_REQUEST);
- if (!(events & DISK_EVENT_MEDIA_CHANGE))
- return 0;
-
- flush_disk(bdev, true);
- if (bdops->revalidate_disk)
- bdops->revalidate_disk(bdev->bd_disk);
- return 1;
-}
-
-EXPORT_SYMBOL(check_disk_change);
-
-void bd_set_size(struct block_device *bdev, loff_t size)
-{
- unsigned bsize = bdev_logical_block_size(bdev);
-
- 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);
-
-static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);
-
-/*
- * bd_mutex locking:
- *
- * mutex_lock(part->bd_mutex)
- * mutex_lock_nested(whole->bd_mutex, 1)
- */
-
-static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
-{
- struct gendisk *disk;
- struct module *owner;
- int ret;
- int partno;
- int perm = 0;
-
- if (mode & FMODE_READ)
- perm |= MAY_READ;
- if (mode & FMODE_WRITE)
- perm |= MAY_WRITE;
- /*
- * hooks: /n/, see "layering violations".
- */
- if (!for_part) {
- ret = devcgroup_inode_permission(bdev->bd_inode, perm);
- if (ret != 0) {
- bdput(bdev);
- return ret;
- }
- }
-
- restart:
-
- ret = -ENXIO;
- disk = get_gendisk(bdev->bd_dev, &partno);
- if (!disk)
- goto out;
- owner = disk->fops->owner;
-
- disk_block_events(disk);
- mutex_lock_nested(&bdev->bd_mutex, for_part);
- if (!bdev->bd_openers) {
- bdev->bd_disk = disk;
- bdev->bd_queue = disk->queue;
- bdev->bd_contains = bdev;
- if (!partno) {
- struct backing_dev_info *bdi;
-
- ret = -ENXIO;
- bdev->bd_part = disk_get_part(disk, partno);
- if (!bdev->bd_part)
- goto out_clear;
-
- ret = 0;
- if (disk->fops->open) {
- ret = disk->fops->open(bdev, mode);
- if (ret == -ERESTARTSYS) {
- /* Lost a race with 'disk' being
- * deleted, try again.
- * See md.c
- */
- disk_put_part(bdev->bd_part);
- bdev->bd_part = NULL;
- bdev->bd_disk = NULL;
- bdev->bd_queue = NULL;
- mutex_unlock(&bdev->bd_mutex);
- disk_unblock_events(disk);
- put_disk(disk);
- module_put(owner);
- goto restart;
- }
- }
-
- 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);
- }
-
- /*
- * 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) {
- if (!ret)
- rescan_partitions(disk, bdev);
- else if (ret == -ENOMEDIUM)
- invalidate_partitions(disk, bdev);
- }
- if (ret)
- goto out_clear;
- } else {
- struct block_device *whole;
- whole = bdget_disk(disk, 0);
- ret = -ENOMEM;
- if (!whole)
- goto out_clear;
- BUG_ON(for_part);
- ret = __blkdev_get(whole, mode, 1);
- if (ret)
- goto out_clear;
- bdev->bd_contains = whole;
- bdev_inode_switch_bdi(bdev->bd_inode,
- whole->bd_inode->i_data.backing_dev_info);
- bdev->bd_part = disk_get_part(disk, partno);
- if (!(disk->flags & GENHD_FL_UP) ||
- !bdev->bd_part || !bdev->bd_part->nr_sects) {
- ret = -ENXIO;
- goto out_clear;
- }
- bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
- }
- } else {
- if (bdev->bd_contains == bdev) {
- ret = 0;
- if (bdev->bd_disk->fops->open)
- ret = bdev->bd_disk->fops->open(bdev, mode);
- /* the same as first opener case, read comment there */
- if (bdev->bd_invalidated) {
- if (!ret)
- rescan_partitions(bdev->bd_disk, bdev);
- else if (ret == -ENOMEDIUM)
- invalidate_partitions(bdev->bd_disk, bdev);
- }
- if (ret)
- goto out_unlock_bdev;
- }
- /* only one opener holds refs to the module and disk */
- put_disk(disk);
- module_put(owner);
- }
- bdev->bd_openers++;
- if (for_part)
- bdev->bd_part_count++;
- mutex_unlock(&bdev->bd_mutex);
- disk_unblock_events(disk);
- return 0;
-
- out_clear:
- disk_put_part(bdev->bd_part);
- bdev->bd_disk = NULL;
- bdev->bd_part = NULL;
- bdev->bd_queue = NULL;
- bdev_inode_switch_bdi(bdev->bd_inode, &default_backing_dev_info);
- if (bdev != bdev->bd_contains)
- __blkdev_put(bdev->bd_contains, mode, 1);
- bdev->bd_contains = NULL;
- out_unlock_bdev:
- mutex_unlock(&bdev->bd_mutex);
- disk_unblock_events(disk);
- put_disk(disk);
- module_put(owner);
- out:
- bdput(bdev);
-
- return ret;
-}
-
-/**
- * blkdev_get - open a block device
- * @bdev: block_device to open
- * @mode: FMODE_* mask
- * @holder: exclusive holder identifier
- *
- * Open @bdev with @mode. If @mode includes %FMODE_EXCL, @bdev is
- * open with exclusive access. Specifying %FMODE_EXCL with %NULL
- * @holder is invalid. Exclusive opens may nest for the same @holder.
- *
- * On success, the reference count of @bdev is unchanged. On failure,
- * @bdev is put.
- *
- * CONTEXT:
- * Might sleep.
- *
- * RETURNS:
- * 0 on success, -errno on failure.
- */
-int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
-{
- 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) {
- struct gendisk *disk = whole->bd_disk;
-
- /* finish claiming */
- mutex_lock(&bdev->bd_mutex);
- spin_lock(&bdev_lock);
-
- if (!res) {
- 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);
-
- /*
- * 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 (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder &&
- (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) {
- bdev->bd_write_holder = true;
- disk_block_events(disk);
- }
-
- mutex_unlock(&bdev->bd_mutex);
- bdput(whole);
- }
-
- return res;
-}
-EXPORT_SYMBOL(blkdev_get);
-
-/**
- * blkdev_get_by_path - open a block device by name
- * @path: path to the block device to open
- * @mode: FMODE_* mask
- * @holder: exclusive holder identifier
- *
- * Open the blockdevice described by the device file at @path. @mode
- * and @holder are identical to blkdev_get().
- *
- * On success, the returned block_device has reference count of one.
- *
- * CONTEXT:
- * Might sleep.
- *
- * RETURNS:
- * Pointer to block_device on success, ERR_PTR(-errno) on failure.
- */
-struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
- void *holder)
-{
- struct block_device *bdev;
- int err;
-
- bdev = lookup_bdev(path);
- if (IS_ERR(bdev))
- return bdev;
-
- err = blkdev_get(bdev, mode, holder);
- if (err)
- return ERR_PTR(err);
-
- if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) {
- blkdev_put(bdev, mode);
- return ERR_PTR(-EACCES);
- }
-
- return bdev;
-}
-EXPORT_SYMBOL(blkdev_get_by_path);
-
-/**
- * blkdev_get_by_dev - open a block device by device number
- * @dev: device number of block device to open
- * @mode: FMODE_* mask
- * @holder: exclusive holder identifier
- *
- * Open the blockdevice described by device number @dev. @mode and
- * @holder are identical to blkdev_get().
- *
- * Use it ONLY if you really do not have anything better - i.e. when
- * you are behind a truly sucky interface and all you are given is a
- * device number. _Never_ to be used for internal purposes. If you
- * ever need it - reconsider your API.
- *
- * On success, the returned block_device has reference count of one.
- *
- * CONTEXT:
- * Might sleep.
- *
- * RETURNS:
- * Pointer to block_device on success, ERR_PTR(-errno) on failure.
- */
-struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder)
-{
- struct block_device *bdev;
- int err;
-
- bdev = bdget(dev);
- if (!bdev)
- return ERR_PTR(-ENOMEM);
-
- err = blkdev_get(bdev, mode, holder);
- if (err)
- return ERR_PTR(err);
-
- return bdev;
-}
-EXPORT_SYMBOL(blkdev_get_by_dev);
-
-static int blkdev_open(struct inode * inode, struct file * filp)
-{
- struct block_device *bdev;
-
- /*
- * Preserve backwards compatibility and allow large file access
- * even if userspace doesn't ask for it explicitly. Some mkfs
- * binary needs it. We might want to drop this workaround
- * during an unstable branch.
- */
- filp->f_flags |= O_LARGEFILE;
-
- if (filp->f_flags & O_NDELAY)
- filp->f_mode |= FMODE_NDELAY;
- if (filp->f_flags & O_EXCL)
- filp->f_mode |= FMODE_EXCL;
- if ((filp->f_flags & O_ACCMODE) == 3)
- filp->f_mode |= FMODE_WRITE_IOCTL;
-
- bdev = bd_acquire(inode);
- if (bdev == NULL)
- return -ENOMEM;
-
- filp->f_mapping = bdev->bd_inode->i_mapping;
-
- return blkdev_get(bdev, filp->f_mode, filp);
-}
-
-static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
-{
- int ret = 0;
- struct gendisk *disk = bdev->bd_disk;
- struct block_device *victim = NULL;
-
- mutex_lock_nested(&bdev->bd_mutex, for_part);
- if (for_part)
- bdev->bd_part_count--;
-
- if (!--bdev->bd_openers) {
- WARN_ON_ONCE(bdev->bd_holders);
- sync_blockdev(bdev);
- kill_bdev(bdev);
- /* ->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);
- }
- if (bdev->bd_contains == bdev) {
- if (disk->fops->release)
- ret = disk->fops->release(disk, mode);
- }
- if (!bdev->bd_openers) {
- struct module *owner = disk->fops->owner;
-
- disk_put_part(bdev->bd_part);
- bdev->bd_part = NULL;
- bdev->bd_disk = NULL;
- if (bdev != bdev->bd_contains)
- victim = bdev->bd_contains;
- bdev->bd_contains = NULL;
-
- put_disk(disk);
- module_put(owner);
- }
- mutex_unlock(&bdev->bd_mutex);
- bdput(bdev);
- if (victim)
- __blkdev_put(victim, mode, 1);
- return ret;
-}
-
-int blkdev_put(struct block_device *bdev, fmode_t mode)
-{
- mutex_lock(&bdev->bd_mutex);
-
- if (mode & FMODE_EXCL) {
- bool bdev_free;
-
- /*
- * Release a claim on the device. The holder fields
- * are protected with bdev_lock. bd_mutex is to
- * synchronize disk_holder unlinking.
- */
- spin_lock(&bdev_lock);
-
- WARN_ON_ONCE(--bdev->bd_holders < 0);
- WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0);
-
- /* bd_contains might point to self, check in a separate step */
- if ((bdev_free = !bdev->bd_holders))
- bdev->bd_holder = NULL;
- if (!bdev->bd_contains->bd_holders)
- bdev->bd_contains->bd_holder = NULL;
-
- spin_unlock(&bdev_lock);
-
- /*
- * If this was the last claim, remove holder link and
- * unblock evpoll if it was a write holder.
- */
- if (bdev_free && bdev->bd_write_holder) {
- disk_unblock_events(bdev->bd_disk);
- bdev->bd_write_holder = false;
- }
- }
-
- /*
- * Trigger event checking and tell drivers to flush MEDIA_CHANGE
- * event. This is to ensure detection of media removal commanded
- * from userland - e.g. eject(1).
- */
- disk_flush_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE);
-
- mutex_unlock(&bdev->bd_mutex);
-
- return __blkdev_put(bdev, mode, 0);
-}
-EXPORT_SYMBOL(blkdev_put);
-
-static int blkdev_close(struct inode * inode, struct file * filp)
-{
- struct block_device *bdev = I_BDEV(filp->f_mapping->host);
-
- return blkdev_put(bdev, filp->f_mode);
-}
-
-static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
-{
- struct block_device *bdev = I_BDEV(file->f_mapping->host);
- fmode_t mode = file->f_mode;
-
- /*
- * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
- * to updated it before every ioctl.
- */
- if (file->f_flags & O_NDELAY)
- mode |= FMODE_NDELAY;
- else
- mode &= ~FMODE_NDELAY;
-
- return blkdev_ioctl(bdev, mode, cmd, arg);
-}
-
-/*
- * Write data to the block device. Only intended for the block device itself
- * and the raw driver which basically is a fake block device.
- *
- * Does not take i_mutex for the write and thus is not for general purpose
- * use.
- */
-ssize_t blkdev_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);
-
-/*
- * Try to release a page associated with block device when the system
- * is under memory pressure.
- */
-static int blkdev_releasepage(struct page *page, gfp_t wait)
-{
- struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super;
-
- if (super && super->s_op->bdev_try_to_free_page)
- return super->s_op->bdev_try_to_free_page(super, page, wait);
-
- return try_to_free_buffers(page);
-}
-
-static const struct address_space_operations def_blk_aops = {
- .readpage = blkdev_readpage,
- .writepage = blkdev_writepage,
- .write_begin = blkdev_write_begin,
- .write_end = blkdev_write_end,
- .writepages = generic_writepages,
- .releasepage = blkdev_releasepage,
- .direct_IO = blkdev_direct_IO,
-};
-
-const struct file_operations def_blk_fops = {
- .open = blkdev_open,
- .release = blkdev_close,
- .llseek = block_llseek,
- .read = do_sync_read,
- .write = do_sync_write,
- .aio_read = generic_file_aio_read,
- .aio_write = blkdev_aio_write,
- .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 = generic_file_splice_write,
-};
-
-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);
- res = blkdev_ioctl(bdev, 0, cmd, arg);
- set_fs(old_fs);
- return res;
-}
-
-EXPORT_SYMBOL(ioctl_by_bdev);
-
-/**
- * lookup_bdev - lookup a struct block_device by name
- * @pathname: special file representing the block device
- *
- * Get a reference to the blockdevice at @pathname in the current
- * namespace if possible and return it. Return ERR_PTR(error)
- * otherwise.
- */
-struct block_device *lookup_bdev(const char *pathname)
-{
- struct block_device *bdev;
- struct inode *inode;
- struct path path;
- int error;
-
- if (!pathname || !*pathname)
- return ERR_PTR(-EINVAL);
-
- error = kern_path(pathname, LOOKUP_FOLLOW, &path);
- if (error)
- return ERR_PTR(error);
-
- inode = path.dentry->d_inode;
- error = -ENOTBLK;
- if (!S_ISBLK(inode->i_mode))
- goto fail;
- error = -EACCES;
- if (path.mnt->mnt_flags & MNT_NODEV)
- goto fail;
- error = -ENOMEM;
- bdev = bd_acquire(inode);
- if (!bdev)
- goto fail;
-out:
- path_put(&path);
- return bdev;
-fail:
- bdev = ERR_PTR(error);
- goto out;
-}
-EXPORT_SYMBOL(lookup_bdev);
-
-int __invalidate_device(struct block_device *bdev, bool kill_dirty)
-{
- struct super_block *sb = get_super(bdev);
- int res = 0;
-
- if (sb) {
- /*
- * no need to lock the super, get_super holds the
- * read mutex so the filesystem cannot go away
- * under us (->put_super runs with the write lock
- * hold).
- */
- shrink_dcache_sb(sb);
- res = invalidate_inodes(sb, kill_dirty);
- drop_super(sb);
- }
- invalidate_bdev(bdev);
- return res;
-}
-EXPORT_SYMBOL(__invalidate_device);