#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"
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);
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)
+{
+ 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
+ *
+ * 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
+ * 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 > 0) {
+ bdev->bd_fsfreeze_count++;
+ sb = get_super(bdev);
+ 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();
+
+ 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;
+ drop_super(sb);
+ up(&bdev->bd_mount_sem);
+ bdev->bd_fsfreeze_count--;
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
+ return ERR_PTR(error);
+ }
+ }
+ }
+
+ sync_blockdev(bdev);
+ mutex_unlock(&bdev->bd_fsfreeze_mutex);
+
+ return sb; /* thaw_bdev releases s->s_umount and bd_mount_sem */
+}
+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 = 0;
+
+ 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);
+ }
+ drop_super(sb);
+ }
+
+ up(&bdev->bd_mount_sem);
+ 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);
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),
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 */
}
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)
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);
}
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) {
}
lock_kernel();
+ restart:
ret = -ENXIO;
disk = get_gendisk(bdev->bd_dev, &partno);
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;
+ module_put(disk->fops->owner);
+ put_disk(disk);
+ bdev->bd_disk = NULL;
+ mutex_unlock(&bdev->bd_mutex);
+ goto restart;
+ }
if (ret)
goto out_clear;
}
return blkdev_ioctl(bdev, mode, cmd, arg);
}
+/*
+ * 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,
};
/**
* lookup_bdev - lookup a struct block_device by name
- * @path: special file representing the block device
+ * @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)