#include <linux/uio.h>
#include <linux/namei.h>
#include <linux/log2.h>
+#include <linux/kmemleak.h>
#include <asm/uaccess.h>
#include "internal.h"
iov, offset, nr_segs, blkdev_get_blocks, NULL);
}
+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)
{
- int ret = 0;
-
- if (bdev)
- ret = filemap_write_and_wait(bdev->bd_inode->i_mapping);
- return ret;
+ return __sync_blockdev(bdev, 1);
}
EXPORT_SYMBOL(sync_blockdev);
{
struct super_block *sb = get_super(bdev);
if (sb) {
- int res = fsync_super(sb);
+ int res = sync_filesystem(sb);
drop_super(sb);
return res;
}
* freeze_bdev -- lock a filesystem and force it into a consistent state
* @bdev: blockdevice to lock
*
- * This takes the block device bd_mount_sem to make sure no new mounts
- * happen on bdev until thaw_bdev() is called.
* 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
int error = 0;
mutex_lock(&bdev->bd_fsfreeze_mutex);
- if (bdev->bd_fsfreeze_count > 0) {
- bdev->bd_fsfreeze_count++;
+ 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;
}
- bdev->bd_fsfreeze_count++;
- down(&bdev->bd_mount_sem);
- sb = get_super(bdev);
- if (sb && !(sb->s_flags & MS_RDONLY)) {
- sb->s_frozen = SB_FREEZE_WRITE;
- smp_wmb();
+ sb = get_active_super(bdev);
+ if (!sb)
+ goto out;
+ if (sb->s_flags & MS_RDONLY) {
+ sb->s_frozen = SB_FREEZE_TRANS;
+ up_write(&sb->s_umount);
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ return sb;
+ }
- __fsync_super(sb);
+ sb->s_frozen = SB_FREEZE_WRITE;
+ smp_wmb();
- sb->s_frozen = SB_FREEZE_TRANS;
- smp_wmb();
-
- sync_blockdev(sb->s_bdev);
-
- if (sb->s_op->freeze_fs) {
- error = sb->s_op->freeze_fs(sb);
- if (error) {
- printk(KERN_ERR
- "VFS:Filesystem freeze failed\n");
- sb->s_frozen = SB_UNFROZEN;
- drop_super(sb);
- up(&bdev->bd_mount_sem);
- bdev->bd_fsfreeze_count--;
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return ERR_PTR(error);
- }
+ sync_filesystem(sb);
+
+ sb->s_frozen = SB_FREEZE_TRANS;
+ smp_wmb();
+
+ sync_blockdev(sb->s_bdev);
+
+ if (sb->s_op->freeze_fs) {
+ error = sb->s_op->freeze_fs(sb);
+ if (error) {
+ printk(KERN_ERR
+ "VFS:Filesystem freeze failed\n");
+ sb->s_frozen = SB_UNFROZEN;
+ deactivate_locked_super(sb);
+ bdev->bd_fsfreeze_count--;
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ return ERR_PTR(error);
}
}
+ up_write(&sb->s_umount);
+ out:
sync_blockdev(bdev);
mutex_unlock(&bdev->bd_fsfreeze_mutex);
-
- return sb; /* thaw_bdev releases s->s_umount and bd_mount_sem */
+ return sb; /* thaw_bdev releases s->s_umount */
}
EXPORT_SYMBOL(freeze_bdev);
*/
int thaw_bdev(struct block_device *bdev, struct super_block *sb)
{
- int error = 0;
+ int error = -EINVAL;
mutex_lock(&bdev->bd_fsfreeze_mutex);
- if (!bdev->bd_fsfreeze_count) {
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return -EINVAL;
- }
-
- bdev->bd_fsfreeze_count--;
- if (bdev->bd_fsfreeze_count > 0) {
- if (sb)
- drop_super(sb);
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return 0;
- }
-
- if (sb) {
- BUG_ON(sb->s_bdev != bdev);
- if (!(sb->s_flags & MS_RDONLY)) {
- if (sb->s_op->unfreeze_fs) {
- error = sb->s_op->unfreeze_fs(sb);
- if (error) {
- printk(KERN_ERR
- "VFS:Filesystem thaw failed\n");
- sb->s_frozen = SB_FREEZE_TRANS;
- bdev->bd_fsfreeze_count++;
- mutex_unlock(&bdev->bd_fsfreeze_mutex);
- return error;
- }
- }
- sb->s_frozen = SB_UNFROZEN;
- smp_wmb();
- wake_up(&sb->s_wait_unfrozen);
+ if (!bdev->bd_fsfreeze_count)
+ goto out_unlock;
+
+ error = 0;
+ if (--bdev->bd_fsfreeze_count > 0)
+ goto out_unlock;
+
+ if (!sb)
+ goto out_unlock;
+
+ BUG_ON(sb->s_bdev != bdev);
+ down_write(&sb->s_umount);
+ if (sb->s_flags & MS_RDONLY)
+ goto out_unfrozen;
+
+ if (sb->s_op->unfreeze_fs) {
+ error = sb->s_op->unfreeze_fs(sb);
+ if (error) {
+ printk(KERN_ERR
+ "VFS:Filesystem thaw failed\n");
+ sb->s_frozen = SB_FREEZE_TRANS;
+ bdev->bd_fsfreeze_count++;
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ return error;
}
- drop_super(sb);
}
- up(&bdev->bd_mount_sem);
+out_unfrozen:
+ sb->s_frozen = SB_UNFROZEN;
+ smp_wmb();
+ wake_up(&sb->s_wait_unfrozen);
+
+ if (sb)
+ deactivate_locked_super(sb);
+out_unlock:
mutex_unlock(&bdev->bd_fsfreeze_mutex);
return 0;
}
return block_read_full_page(page, blkdev_get_block);
}
-static int blkdev_readpages(struct file *file, struct address_space *mapping,
- struct list_head *pages, unsigned nr_pages)
-{
- return mpage_readpages(mapping, pages, nr_pages, 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)
* 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, struct dentry *dentry, 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, NULL);
+ 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);
}
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
bd_mnt = kern_mount(&bd_type);
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 */
}
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;
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;
bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
}
} else {
- put_disk(disk);
module_put(disk->fops->owner);
+ put_disk(disk);
disk = NULL;
if (bdev->bd_contains == bdev) {
if (bdev->bd_disk->fops->open) {
}
/*
+ * 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 const struct address_space_operations def_blk_aops = {
.readpage = blkdev_readpage,
- .readpages = blkdev_readpages,
.writepage = blkdev_writepage,
.sync_page = block_sync_page,
.write_begin = blkdev_write_begin,
.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,
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff