#include <linux/kmod.h>
#include <linux/major.h>
#include <linux/smp_lock.h>
+#include <linux/device_cgroup.h>
#include <linux/highmem.h>
#include <linux/blkdev.h>
#include <linux/module.h>
#include <linux/blkpg.h>
#include <linux/buffer_head.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/kmemleak.h>
#include <asm/uaccess.h>
#include "internal.h"
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);
return -EINVAL;
/* Size cannot be smaller than the size supported by the device */
- if (size < bdev_hardsect_size(bdev))
+ if (size < bdev_logical_block_size(bdev))
return -EINVAL;
/* Don't change the size if it is same as current */
int sb_min_blocksize(struct super_block *sb, int size)
{
- int minsize = bdev_hardsect_size(sb->s_bdev);
+ int minsize = bdev_logical_block_size(sb->s_bdev);
if (size < minsize)
size = minsize;
return sb_set_blocksize(sb, size);
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
- return blockdev_direct_IO_no_locking(rw, iocb, inode, I_BDEV(inode),
- iov, offset, nr_segs, blkdev_get_blocks, NULL);
+ return blockdev_direct_IO_no_locking_newtrunc(rw, iocb, inode,
+ I_BDEV(inode), iov, offset, nr_segs,
+ blkdev_get_blocks, NULL);
}
-#if 0
-static int blk_end_aio(struct bio *bio, unsigned int bytes_done, int error)
+int __sync_blockdev(struct block_device *bdev, int wait)
{
- struct kiocb *iocb = bio->bi_private;
- atomic_t *bio_count = &iocb->ki_bio_count;
-
- if (bio_data_dir(bio) == READ)
- bio_check_pages_dirty(bio);
- else {
- bio_release_pages(bio);
- bio_put(bio);
- }
-
- /* iocb->ki_nbytes stores error code from LLDD */
- if (error)
- iocb->ki_nbytes = -EIO;
-
- if (atomic_dec_and_test(bio_count)) {
- if ((long)iocb->ki_nbytes < 0)
- aio_complete(iocb, iocb->ki_nbytes, 0);
- else
- aio_complete(iocb, iocb->ki_left, 0);
- }
-
- return 0;
+ if (!bdev)
+ return 0;
+ if (!wait)
+ return filemap_flush(bdev->bd_inode->i_mapping);
+ return filemap_write_and_wait(bdev->bd_inode->i_mapping);
}
-#define VEC_SIZE 16
-struct pvec {
- unsigned short nr;
- unsigned short idx;
- struct page *page[VEC_SIZE];
-};
-
-#define PAGES_SPANNED(addr, len) \
- (DIV_ROUND_UP((addr) + (len), PAGE_SIZE) - (addr) / PAGE_SIZE);
-
/*
- * get page pointer for user addr, we internally cache struct page array for
- * (addr, count) range in pvec to avoid frequent call to get_user_pages. If
- * internal page list is exhausted, a batch count of up to VEC_SIZE is used
- * to get next set of page struct.
+ * Write out and wait upon all the dirty data associated with a block
+ * device via its mapping. Does not take the superblock lock.
*/
-static struct page *blk_get_page(unsigned long addr, size_t count, int rw,
- struct pvec *pvec)
-{
- int ret, nr_pages;
- if (pvec->idx == pvec->nr) {
- nr_pages = PAGES_SPANNED(addr, count);
- nr_pages = min(nr_pages, VEC_SIZE);
- down_read(¤t->mm->mmap_sem);
- ret = get_user_pages(current, current->mm, addr, nr_pages,
- rw == READ, 0, pvec->page, NULL);
- up_read(¤t->mm->mmap_sem);
- if (ret < 0)
- return ERR_PTR(ret);
- pvec->nr = ret;
- pvec->idx = 0;
- }
- return pvec->page[pvec->idx++];
+int sync_blockdev(struct block_device *bdev)
+{
+ return __sync_blockdev(bdev, 1);
}
+EXPORT_SYMBOL(sync_blockdev);
-/* return a page back to pvec array */
-static void blk_unget_page(struct page *page, struct pvec *pvec)
+/*
+ * 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)
{
- pvec->page[--pvec->idx] = page;
+ 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);
-static ssize_t
-blkdev_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
- loff_t pos, unsigned long nr_segs)
-{
- struct inode *inode = iocb->ki_filp->f_mapping->host;
- unsigned blkbits = blksize_bits(bdev_hardsect_size(I_BDEV(inode)));
- unsigned blocksize_mask = (1 << blkbits) - 1;
- unsigned long seg = 0; /* iov segment iterator */
- unsigned long nvec; /* number of bio vec needed */
- unsigned long cur_off; /* offset into current page */
- unsigned long cur_len; /* I/O len of current page, up to PAGE_SIZE */
-
- unsigned long addr; /* user iovec address */
- size_t count; /* user iovec len */
- size_t nbytes = iocb->ki_nbytes = iocb->ki_left; /* total xfer size */
- loff_t size; /* size of block device */
- struct bio *bio;
- atomic_t *bio_count = &iocb->ki_bio_count;
- struct page *page;
- struct pvec pvec;
-
- pvec.nr = 0;
- pvec.idx = 0;
-
- if (pos & blocksize_mask)
- return -EINVAL;
+/**
+ * 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;
- size = i_size_read(inode);
- if (pos + nbytes > size) {
- nbytes = size - pos;
- iocb->ki_left = nbytes;
+ 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;
}
- /*
- * check first non-zero iov alignment, the remaining
- * iov alignment is checked inside bio loop below.
- */
- do {
- addr = (unsigned long) iov[seg].iov_base;
- count = min(iov[seg].iov_len, nbytes);
- if (addr & blocksize_mask || count & blocksize_mask)
- return -EINVAL;
- } while (!count && ++seg < nr_segs);
- atomic_set(bio_count, 1);
-
- while (nbytes) {
- /* roughly estimate number of bio vec needed */
- nvec = (nbytes + PAGE_SIZE - 1) / PAGE_SIZE;
- nvec = max(nvec, nr_segs - seg);
- nvec = min(nvec, (unsigned long) BIO_MAX_PAGES);
-
- /* bio_alloc should not fail with GFP_KERNEL flag */
- bio = bio_alloc(GFP_KERNEL, nvec);
- bio->bi_bdev = I_BDEV(inode);
- bio->bi_end_io = blk_end_aio;
- bio->bi_private = iocb;
- bio->bi_sector = pos >> blkbits;
-same_bio:
- cur_off = addr & ~PAGE_MASK;
- cur_len = PAGE_SIZE - cur_off;
- if (count < cur_len)
- cur_len = count;
-
- page = blk_get_page(addr, count, rw, &pvec);
- if (unlikely(IS_ERR(page)))
- goto backout;
-
- if (bio_add_page(bio, page, cur_len, cur_off)) {
- pos += cur_len;
- addr += cur_len;
- count -= cur_len;
- nbytes -= cur_len;
-
- if (count)
- goto same_bio;
- while (++seg < nr_segs) {
- addr = (unsigned long) iov[seg].iov_base;
- count = iov[seg].iov_len;
- if (!count)
- continue;
- if (unlikely(addr & blocksize_mask ||
- count & blocksize_mask)) {
- page = ERR_PTR(-EINVAL);
- goto backout;
- }
- count = min(count, nbytes);
- goto same_bio;
- }
- } else {
- blk_unget_page(page, &pvec);
- }
-
- /* bio is ready, submit it */
- if (rw == READ)
- bio_set_pages_dirty(bio);
- atomic_inc(bio_count);
- submit_bio(rw, bio);
+ 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);
-completion:
- iocb->ki_left -= nbytes;
- nbytes = iocb->ki_left;
- iocb->ki_pos += nbytes;
+/**
+ * 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;
- blk_run_address_space(inode->i_mapping);
- if (atomic_dec_and_test(bio_count))
- aio_complete(iocb, nbytes, 0);
+ mutex_lock(&bdev->bd_fsfreeze_mutex);
+ if (!bdev->bd_fsfreeze_count)
+ goto out;
- return -EIOCBQUEUED;
+ error = 0;
+ if (--bdev->bd_fsfreeze_count > 0)
+ goto out;
-backout:
- /*
- * back out nbytes count constructed so far for this bio,
- * we will throw away current bio.
- */
- nbytes += bio->bi_size;
- bio_release_pages(bio);
- bio_put(bio);
+ if (!sb)
+ goto out;
- /*
- * if no bio was submmitted, return the error code.
- * otherwise, proceed with pending I/O completion.
- */
- if (atomic_read(bio_count) == 1)
- return PTR_ERR(page);
- goto completion;
+ 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;
}
-#endif
+EXPORT_SYMBOL(thaw_bdev);
static int blkdev_writepage(struct page *page, struct writeback_control *wbc)
{
return block_read_full_page(page, blkdev_get_block);
}
-static int blkdev_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
+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_prepare_write(page, from, to, blkdev_get_block);
+ *pagep = NULL;
+ return block_write_begin_newtrunc(file, mapping, pos, len, flags,
+ pagep, fsdata, blkdev_get_block);
}
-static int blkdev_commit_write(struct file *file, struct page *page, unsigned from, unsigned to)
+static int blkdev_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
{
- return block_commit_write(page, from, to);
+ int ret;
+ ret = block_write_end(file, mapping, pos, len, copied, page, fsdata);
+
+ unlock_page(page);
+ page_cache_release(page);
+
+ return ret;
}
/*
return retval;
}
-/*
- * Filp is never NULL; the only case when ->fsync() is called with
- * NULL first argument is nfsd_sync_dir() and that's not a directory.
- */
-
-static int block_fsync(struct file *filp, struct dentry *dentry, int datasync)
+int blkdev_fsync(struct file *filp, int datasync)
{
- return sync_blockdev(I_BDEV(filp->f_mapping->host));
+ struct inode *bd_inode = filp->f_mapping->host;
+ struct block_device *bdev = I_BDEV(bd_inode);
+ int 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.
+ */
+ mutex_unlock(&bd_inode->i_mutex);
+
+ error = blkdev_issue_flush(bdev, GFP_KERNEL, NULL, BLKDEV_IFL_WAIT);
+ if (error == -EOPNOTSUPP)
+ error = 0;
+
+ mutex_lock(&bd_inode->i_mutex);
+
+ return error;
}
+EXPORT_SYMBOL(blkdev_fsync);
/*
* pseudo-fs
{
struct bdev_inode *bdi = BDEV_I(inode);
- bdi->bdev.bd_inode_backing_dev_info = NULL;
kmem_cache_free(bdev_cachep, bdi);
}
-static void init_once(void * foo, struct kmem_cache * cachep, unsigned long flags)
+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);
- sema_init(&bdev->bd_mount_sem, 1);
INIT_LIST_HEAD(&bdev->bd_inodes);
INIT_LIST_HEAD(&bdev->bd_list);
#ifdef CONFIG_SYSFS
INIT_LIST_HEAD(&bdev->bd_holder_list);
#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)
.kill_sb = kill_anon_super,
};
-static struct vfsmount *bd_mnt __read_mostly;
-struct super_block *blockdev_superblock;
+struct super_block *blockdev_superblock __read_mostly;
void __init bdev_cache_init(void)
{
int err;
+ 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),
if (err)
panic("Cannot register bdev pseudo-fs");
bd_mnt = kern_mount(&bd_type);
- err = PTR_ERR(bd_mnt);
if (IS_ERR(bd_mnt))
panic("Cannot create bdev pseudo-fs");
+ /*
+ * This vfsmount structure is only used to obtain the
+ * blockdev_superblock, so tell kmemleak not to report it.
+ */
+ kmemleak_not_leak(bd_mnt);
blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */
}
struct block_device *bdev;
struct inode *inode;
- inode = iget5_locked(bd_mnt->mnt_sb, hash(dev),
+ inode = iget5_locked(blockdev_superblock, hash(dev),
bdev_test, bdev_set, &dev);
if (!inode)
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)
+{
+ atomic_inc(&bdev->bd_inode->i_count);
+ return bdev;
+}
+
long nr_blockdev_pages(void)
{
struct block_device *bdev;
spin_lock(&bdev_lock);
if (inode->i_bdev) {
- if (inode->i_sb != blockdev_superblock)
+ if (!sb_is_blkdev_sb(inode->i_sb))
bdev = inode->i_bdev;
__bd_forget(inode);
}
iput(bdev->bd_inode);
}
-int bd_claim(struct block_device *bdev, void *holder)
+/**
+ * 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 whther @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)
{
- int res;
- spin_lock(&bdev_lock);
-
- /* first decide result */
if (bdev->bd_holder == holder)
- res = 0; /* already a holder */
+ return true; /* already a holder */
else if (bdev->bd_holder != NULL)
- res = -EBUSY; /* held by someone else */
+ return false; /* held by someone else */
else if (bdev->bd_contains == bdev)
- res = 0; /* is a whole device which isn't held */
+ return true; /* is a whole device which isn't held */
- else if (bdev->bd_contains->bd_holder == bd_claim)
- res = 0; /* is a partition of a device that is being partitioned */
- else if (bdev->bd_contains->bd_holder != NULL)
- res = -EBUSY; /* is a partition of a held device */
+ else if (whole->bd_holder == bd_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
- res = 0; /* is a partition of an un-held device */
+ return true; /* is a partition of an un-held device */
+}
- /* now impose change */
- if (res==0) {
- /* note that for a whole device bd_holders
- * will be incremented twice, and bd_holder will
- * be set to bd_claim before being set to holder
- */
- bdev->bd_contains->bd_holders ++;
- bdev->bd_contains->bd_holder = bd_claim;
- bdev->bd_holders++;
- bdev->bd_holder = holder;
+/**
+ * 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 someone else is claiming, wait for it to finish */
+ if (whole->bd_claiming && whole->bd_claiming != holder) {
+ 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);
+
+ whole = bdget_disk(disk, 0);
+ 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);
+ }
+}
+
+/* releases bdev_lock */
+static void __bd_abort_claiming(struct block_device *whole, void *holder)
+{
+ BUG_ON(whole->bd_claiming != holder);
+ whole->bd_claiming = NULL;
+ wake_up_bit(&whole->bd_claiming, 0);
+
spin_unlock(&bdev_lock);
- return res;
+ bdput(whole);
}
+/**
+ * bd_abort_claiming - abort claiming a block device
+ * @whole: whole block device returned by bd_start_claiming()
+ * @holder: holder trying to claim @bdev
+ *
+ * Abort a claiming block started by bd_start_claiming(). Note that
+ * @whole is not the block device to be claimed but the whole device
+ * returned by bd_start_claiming().
+ *
+ * CONTEXT:
+ * Grabs and releases bdev_lock.
+ */
+static void bd_abort_claiming(struct block_device *whole, void *holder)
+{
+ spin_lock(&bdev_lock);
+ __bd_abort_claiming(whole, holder); /* releases bdev_lock */
+}
+
+/* increment holders when we have a legitimate claim. requires bdev_lock */
+static void __bd_claim(struct block_device *bdev, struct block_device *whole,
+ void *holder)
+{
+ /* note that for a whole device bd_holders
+ * will be incremented twice, and bd_holder will
+ * be set to bd_claim before being set to holder
+ */
+ whole->bd_holders++;
+ whole->bd_holder = bd_claim;
+ bdev->bd_holders++;
+ bdev->bd_holder = holder;
+}
+
+/**
+ * bd_finish_claiming - finish claiming a block device
+ * @bdev: block device of interest (passed to bd_start_claiming())
+ * @whole: whole block device returned by bd_start_claiming()
+ * @holder: holder trying to claim @bdev
+ *
+ * Finish a claiming block started by bd_start_claiming().
+ *
+ * CONTEXT:
+ * Grabs and releases bdev_lock.
+ */
+static void bd_finish_claiming(struct block_device *bdev,
+ struct block_device *whole, void *holder)
+{
+ spin_lock(&bdev_lock);
+ BUG_ON(!bd_may_claim(bdev, whole, holder));
+ __bd_claim(bdev, whole, holder);
+ __bd_abort_claiming(whole, holder); /* not actually an abort */
+}
+
+/**
+ * bd_claim - claim a block device
+ * @bdev: block device to claim
+ * @holder: holder trying to claim @bdev
+ *
+ * Try to claim @bdev which must have been opened successfully.
+ *
+ * CONTEXT:
+ * Might sleep.
+ *
+ * RETURNS:
+ * 0 if successful, -EBUSY if @bdev is already claimed.
+ */
+int bd_claim(struct block_device *bdev, void *holder)
+{
+ struct block_device *whole = bdev->bd_contains;
+ int res;
+
+ might_sleep();
+
+ spin_lock(&bdev_lock);
+ res = bd_prepare_to_claim(bdev, whole, holder);
+ if (res == 0)
+ __bd_claim(bdev, whole, holder);
+ spin_unlock(&bdev_lock);
+
+ return res;
+}
EXPORT_SYMBOL(bd_claim);
void bd_release(struct block_device *bdev)
* /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
*/
-static struct kobject *bdev_get_kobj(struct block_device *bdev)
-{
- if (bdev->bd_contains != bdev)
- return kobject_get(&bdev->bd_part->kobj);
- else
- return kobject_get(&bdev->bd_disk->kobj);
-}
-
-static struct kobject *bdev_get_holder(struct block_device *bdev)
-{
- if (bdev->bd_contains != bdev)
- return kobject_get(bdev->bd_part->holder_dir);
- else
- return kobject_get(bdev->bd_disk->holder_dir);
-}
-
static int add_symlink(struct kobject *from, struct kobject *to)
{
if (!from || !to)
if (!bo->hdev)
goto fail_put_sdir;
- bo->sdev = bdev_get_kobj(bdev);
+ bo->sdev = kobject_get(&part_to_dev(bdev->bd_part)->kobj);
if (!bo->sdev)
goto fail_put_hdev;
- bo->hdir = bdev_get_holder(bdev);
+ bo->hdir = kobject_get(bdev->bd_part->holder_dir);
if (!bo->hdir)
goto fail_put_sdev;
* to be used for internal purposes. If you ever need it - reconsider
* your API.
*/
-struct block_device *open_by_devnum(dev_t dev, unsigned mode)
+struct block_device *open_by_devnum(dev_t dev, fmode_t mode)
{
struct block_device *bdev = bdget(dev);
int err = -ENOMEM;
- int flags = mode & FMODE_WRITE ? O_RDWR : O_RDONLY;
if (bdev)
- err = blkdev_get(bdev, mode, flags);
+ err = blkdev_get(bdev, mode);
return err ? ERR_PTR(err) : bdev;
}
EXPORT_SYMBOL(open_by_devnum);
+/**
+ * flush_disk - invalidates all buffer-cache entries on a disk
+ *
+ * @bdev: struct block device to be flushed
+ *
+ * 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)
+{
+ if (__invalidate_device(bdev)) {
+ 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_partitionable(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);
+ }
+}
+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
int check_disk_change(struct block_device *bdev)
{
struct gendisk *disk = bdev->bd_disk;
- struct block_device_operations * bdops = disk->fops;
+ const struct block_device_operations *bdops = disk->fops;
if (!bdops->media_changed)
return 0;
if (!bdops->media_changed(bdev->bd_disk))
return 0;
- if (__invalidate_device(bdev))
- printk("VFS: busy inodes on changed media.\n");
-
+ flush_disk(bdev);
if (bdops->revalidate_disk)
bdops->revalidate_disk(bdev->bd_disk);
- if (bdev->bd_disk->minors > 1)
- bdev->bd_invalidated = 1;
return 1;
}
void bd_set_size(struct block_device *bdev, loff_t size)
{
- unsigned bsize = bdev_hardsect_size(bdev);
+ unsigned bsize = bdev_logical_block_size(bdev);
bdev->bd_inode->i_size = size;
while (bsize < PAGE_CACHE_SIZE) {
}
EXPORT_SYMBOL(bd_set_size);
-static int __blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags,
- int for_part);
-static int __blkdev_put(struct block_device *bdev, int for_part);
+static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part);
/*
* bd_mutex locking:
* mutex_lock_nested(whole->bd_mutex, 1)
*/
-static int do_open(struct block_device *bdev, struct file *file, int for_part)
+static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
{
- struct module *owner = NULL;
struct gendisk *disk;
- int ret = -ENXIO;
- int part;
-
- file->f_mapping = bdev->bd_inode->i_mapping;
- lock_kernel();
- disk = get_gendisk(bdev->bd_dev, &part);
- if (!disk) {
- unlock_kernel();
+ 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".
+ */
+ ret = devcgroup_inode_permission(bdev->bd_inode, perm);
+ if (ret != 0) {
bdput(bdev);
return ret;
}
- owner = disk->fops->owner;
+
+ lock_kernel();
+ restart:
+
+ ret = -ENXIO;
+ disk = get_gendisk(bdev->bd_dev, &partno);
+ if (!disk)
+ goto out_unlock_kernel;
mutex_lock_nested(&bdev->bd_mutex, for_part);
if (!bdev->bd_openers) {
bdev->bd_disk = disk;
bdev->bd_contains = bdev;
- if (!part) {
+ if (!partno) {
struct backing_dev_info *bdi;
+
+ ret = -ENXIO;
+ bdev->bd_part = disk_get_part(disk, partno);
+ if (!bdev->bd_part)
+ goto out_clear;
+
if (disk->fops->open) {
- ret = disk->fops->open(bdev->bd_inode, file);
+ 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;
+ module_put(disk->fops->owner);
+ put_disk(disk);
+ bdev->bd_disk = NULL;
+ mutex_unlock(&bdev->bd_mutex);
+ goto restart;
+ }
if (ret)
- goto out_first;
+ goto out_clear;
}
if (!bdev->bd_openers) {
bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
if (bdev->bd_invalidated)
rescan_partitions(disk, bdev);
} else {
- struct hd_struct *p;
struct block_device *whole;
whole = bdget_disk(disk, 0);
ret = -ENOMEM;
if (!whole)
- goto out_first;
+ goto out_clear;
BUG_ON(for_part);
- ret = __blkdev_get(whole, file->f_mode, file->f_flags, 1);
+ ret = __blkdev_get(whole, mode, 1);
if (ret)
- goto out_first;
+ goto out_clear;
bdev->bd_contains = whole;
- p = disk->part[part - 1];
bdev->bd_inode->i_data.backing_dev_info =
whole->bd_inode->i_data.backing_dev_info;
- if (!(disk->flags & GENHD_FL_UP) || !p || !p->nr_sects) {
+ 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_first;
+ goto out_clear;
}
- kobject_get(&p->kobj);
- bdev->bd_part = p;
- bd_set_size(bdev, (loff_t) p->nr_sects << 9);
+ bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
}
} else {
+ module_put(disk->fops->owner);
put_disk(disk);
- module_put(owner);
+ disk = NULL;
if (bdev->bd_contains == bdev) {
if (bdev->bd_disk->fops->open) {
- ret = bdev->bd_disk->fops->open(bdev->bd_inode, file);
+ ret = bdev->bd_disk->fops->open(bdev, mode);
if (ret)
- goto out;
+ goto out_unlock_bdev;
}
if (bdev->bd_invalidated)
rescan_partitions(bdev->bd_disk, bdev);
unlock_kernel();
return 0;
-out_first:
+ out_clear:
+ disk_put_part(bdev->bd_part);
bdev->bd_disk = NULL;
+ bdev->bd_part = NULL;
bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
if (bdev != bdev->bd_contains)
- __blkdev_put(bdev->bd_contains, 1);
+ __blkdev_put(bdev->bd_contains, mode, 1);
bdev->bd_contains = NULL;
- put_disk(disk);
- module_put(owner);
-out:
+ out_unlock_bdev:
mutex_unlock(&bdev->bd_mutex);
+ out_unlock_kernel:
unlock_kernel();
- if (ret)
- bdput(bdev);
- return ret;
-}
-static int __blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags,
- int for_part)
-{
- /*
- * This crockload is due to bad choice of ->open() type.
- * It will go away.
- * For now, block device ->open() routine must _not_
- * examine anything in 'inode' argument except ->i_rdev.
- */
- struct file fake_file = {};
- struct dentry fake_dentry = {};
- fake_file.f_mode = mode;
- fake_file.f_flags = flags;
- fake_file.f_path.dentry = &fake_dentry;
- fake_dentry.d_inode = bdev->bd_inode;
+ if (disk)
+ module_put(disk->fops->owner);
+ put_disk(disk);
+ bdput(bdev);
- return do_open(bdev, &fake_file, for_part);
+ return ret;
}
-int blkdev_get(struct block_device *bdev, mode_t mode, unsigned flags)
+int blkdev_get(struct block_device *bdev, fmode_t mode)
{
- return __blkdev_get(bdev, mode, flags, 0);
+ return __blkdev_get(bdev, mode, 0);
}
EXPORT_SYMBOL(blkdev_get);
static int blkdev_open(struct inode * inode, struct file * filp)
{
+ struct block_device *whole = NULL;
struct block_device *bdev;
int res;
*/
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;
- res = do_open(bdev, filp, 0);
- if (res)
- return res;
+ if (filp->f_mode & FMODE_EXCL) {
+ whole = bd_start_claiming(bdev, filp);
+ if (IS_ERR(whole)) {
+ bdput(bdev);
+ return PTR_ERR(whole);
+ }
+ }
- if (!(filp->f_flags & O_EXCL) )
- return 0;
+ filp->f_mapping = bdev->bd_inode->i_mapping;
- if (!(res = bd_claim(bdev, filp)))
- return 0;
+ res = blkdev_get(bdev, filp->f_mode);
+
+ if (whole) {
+ if (res == 0)
+ bd_finish_claiming(bdev, whole, filp);
+ else
+ bd_abort_claiming(whole, filp);
+ }
- blkdev_put(bdev);
return res;
}
-static int __blkdev_put(struct block_device *bdev, int for_part)
+static int __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part)
{
int ret = 0;
- struct inode *bd_inode = bdev->bd_inode;
struct gendisk *disk = bdev->bd_disk;
struct block_device *victim = NULL;
}
if (bdev->bd_contains == bdev) {
if (disk->fops->release)
- ret = disk->fops->release(bd_inode, NULL);
+ ret = disk->fops->release(disk, mode);
}
if (!bdev->bd_openers) {
struct module *owner = disk->fops->owner;
put_disk(disk);
module_put(owner);
-
- if (bdev->bd_contains != bdev) {
- kobject_put(&bdev->bd_part->kobj);
- bdev->bd_part = NULL;
- }
+ disk_put_part(bdev->bd_part);
+ bdev->bd_part = NULL;
bdev->bd_disk = NULL;
bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
if (bdev != bdev->bd_contains)
mutex_unlock(&bdev->bd_mutex);
bdput(bdev);
if (victim)
- __blkdev_put(victim, 1);
+ __blkdev_put(victim, mode, 1);
return ret;
}
-int blkdev_put(struct block_device *bdev)
+int blkdev_put(struct block_device *bdev, fmode_t mode)
{
- return __blkdev_put(bdev, 0);
+ return __blkdev_put(bdev, mode, 0);
}
EXPORT_SYMBOL(blkdev_put);
struct block_device *bdev = I_BDEV(filp->f_mapping->host);
if (bdev->bd_holder == filp)
bd_release(bdev);
- return blkdev_put(bdev);
+ return blkdev_put(bdev, filp->f_mode);
}
static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
{
- return blkdev_ioctl(file->f_mapping->host, file, cmd, 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);
-const struct address_space_operations def_blk_aops = {
+/*
+ * 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,
.sync_page = block_sync_page,
- .prepare_write = blkdev_prepare_write,
- .commit_write = blkdev_commit_write,
+ .write_begin = blkdev_write_begin,
+ .write_end = blkdev_write_end,
.writepages = generic_writepages,
+ .releasepage = blkdev_releasepage,
.direct_IO = blkdev_direct_IO,
};
.read = do_sync_read,
.write = do_sync_write,
.aio_read = generic_file_aio_read,
- .aio_write = generic_file_aio_write_nolock,
+ .aio_write = blkdev_aio_write,
.mmap = generic_file_mmap,
- .fsync = block_fsync,
+ .fsync = blkdev_fsync,
.unlocked_ioctl = block_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = compat_blkdev_ioctl,
int res;
mm_segment_t old_fs = get_fs();
set_fs(KERNEL_DS);
- res = blkdev_ioctl(bdev->bd_inode, NULL, cmd, arg);
+ res = blkdev_ioctl(bdev, 0, cmd, arg);
set_fs(old_fs);
return res;
}
/**
* lookup_bdev - lookup a struct block_device by name
+ * @pathname: special file representing the block device
*
- * @path: special file representing the block device
- *
- * Get a reference to the blockdevice at @path in the current
+ * 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 *path)
+struct block_device *lookup_bdev(const char *pathname)
{
struct block_device *bdev;
struct inode *inode;
- struct nameidata nd;
+ struct path path;
int error;
- if (!path || !*path)
+ if (!pathname || !*pathname)
return ERR_PTR(-EINVAL);
- error = path_lookup(path, LOOKUP_FOLLOW, &nd);
+ error = kern_path(pathname, LOOKUP_FOLLOW, &path);
if (error)
return ERR_PTR(error);
- inode = nd.dentry->d_inode;
+ inode = path.dentry->d_inode;
error = -ENOTBLK;
if (!S_ISBLK(inode->i_mode))
goto fail;
error = -EACCES;
- if (nd.mnt->mnt_flags & MNT_NODEV)
+ if (path.mnt->mnt_flags & MNT_NODEV)
goto fail;
error = -ENOMEM;
bdev = bd_acquire(inode);
if (!bdev)
goto fail;
out:
- path_release(&nd);
+ path_put(&path);
return bdev;
fail:
bdev = ERR_PTR(error);
goto out;
}
+EXPORT_SYMBOL(lookup_bdev);
/**
- * open_bdev_excl - open a block device by name and set it up for use
+ * open_bdev_exclusive - open a block device by name and set it up for use
*
* @path: special file representing the block device
- * @flags: %MS_RDONLY for opening read-only
+ * @mode: FMODE_... combination to pass be used
* @holder: owner for exclusion
*
* Open the blockdevice described by the special file at @path, claim it
* for the @holder.
*/
-struct block_device *open_bdev_excl(const char *path, int flags, void *holder)
+struct block_device *open_bdev_exclusive(const char *path, fmode_t mode, void *holder)
{
- struct block_device *bdev;
- mode_t mode = FMODE_READ;
- int error = 0;
+ struct block_device *bdev, *whole;
+ int error;
bdev = lookup_bdev(path);
if (IS_ERR(bdev))
return bdev;
- if (!(flags & MS_RDONLY))
- mode |= FMODE_WRITE;
- error = blkdev_get(bdev, mode, 0);
+ whole = bd_start_claiming(bdev, holder);
+ if (IS_ERR(whole)) {
+ bdput(bdev);
+ return whole;
+ }
+
+ error = blkdev_get(bdev, mode);
if (error)
- return ERR_PTR(error);
+ goto out_abort_claiming;
+
error = -EACCES;
- if (!(flags & MS_RDONLY) && bdev_read_only(bdev))
- goto blkdev_put;
- error = bd_claim(bdev, holder);
- if (error)
- goto blkdev_put;
+ if ((mode & FMODE_WRITE) && bdev_read_only(bdev))
+ goto out_blkdev_put;
+ bd_finish_claiming(bdev, whole, holder);
return bdev;
-
-blkdev_put:
- blkdev_put(bdev);
+
+out_blkdev_put:
+ blkdev_put(bdev, mode);
+out_abort_claiming:
+ bd_abort_claiming(whole, holder);
return ERR_PTR(error);
}
-EXPORT_SYMBOL(open_bdev_excl);
+EXPORT_SYMBOL(open_bdev_exclusive);
/**
- * close_bdev_excl - release a blockdevice openen by open_bdev_excl()
+ * close_bdev_exclusive - close a blockdevice opened by open_bdev_exclusive()
*
* @bdev: blockdevice to close
+ * @mode: mode, must match that used to open.
*
- * This is the counterpart to open_bdev_excl().
+ * This is the counterpart to open_bdev_exclusive().
*/
-void close_bdev_excl(struct block_device *bdev)
+void close_bdev_exclusive(struct block_device *bdev, fmode_t mode)
{
bd_release(bdev);
- blkdev_put(bdev);
+ blkdev_put(bdev, mode);
}
-EXPORT_SYMBOL(close_bdev_excl);
+EXPORT_SYMBOL(close_bdev_exclusive);
int __invalidate_device(struct block_device *bdev)
{
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff