@@ -717,12 +717,15 @@ void del_gendisk_queue(struct gendisk *disk)
blk_cleanup_queue(disk->queue);
- /* pass2 the queue is dead */
+ /* pass2 the queue is dead, halt dax */
disk_part_iter_init(&piter, disk,
DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
- for_each_part(part, &piter)
+ for_each_part(part, &piter) {
+ force_failure_partition(disk, part->partno);
delete_partition(disk, part->partno);
+ }
disk_part_iter_exit(&piter);
+ force_failure_partition(disk, 0);
del_gendisk_end(disk);
}
@@ -1799,6 +1799,25 @@ int __invalidate_device(struct block_device *bdev, bool kill_dirty)
}
EXPORT_SYMBOL(__invalidate_device);
+void force_failure_partition(struct gendisk *disk, int partno)
+{
+ struct block_device *bdev;
+ struct super_block *sb;
+
+ bdev = bdget_disk(disk, partno);
+ if (!bdev)
+ return;
+
+ sb = get_super(bdev);
+ if (!sb)
+ goto out;
+
+ unmap_dax_inodes(sb);
+ drop_super(sb);
+ out:
+ bdput(bdev);
+}
+
void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg)
{
struct inode *inode, *old_inode = NULL;
@@ -673,6 +673,34 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty)
return busy;
}
+void unmap_dax_inodes(struct super_block *sb)
+{
+ struct inode *inode, *_inode = NULL;
+
+ spin_lock(&sb->s_inode_list_lock);
+ list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
+ spin_lock(&inode->i_lock);
+ if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
+ || !IS_DAX(inode)) {
+ spin_unlock(&inode->i_lock);
+ continue;
+ }
+ __iget(inode);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&sb->s_inode_list_lock);
+
+ unmap_mapping_range(inode->i_mapping, 0, 0, 1);
+ iput(_inode);
+ _inode = inode;
+ cond_resched();
+
+ spin_lock(&sb->s_inode_list_lock);
+ }
+ spin_unlock(&sb->s_inode_list_lock);
+ iput(_inode);
+}
+EXPORT_SYMBOL(unmap_dax_inodes);
+
/*
* Isolate the inode from the LRU in preparation for freeing it.
*
@@ -2390,6 +2390,7 @@ extern int revalidate_disk(struct gendisk *);
extern int check_disk_change(struct block_device *);
extern int __invalidate_device(struct block_device *, bool);
extern int invalidate_partition(struct gendisk *, int);
+extern void force_failure_partition(struct gendisk *, int);
#endif
unsigned long invalidate_mapping_pages(struct address_space *mapping,
pgoff_t start, pgoff_t end);
@@ -2544,6 +2545,7 @@ extern loff_t default_llseek(struct file *file, loff_t offset, int whence);
extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);
+extern void unmap_dax_inodes(struct super_block *sb);
extern int inode_init_always(struct super_block *, struct inode *);
extern void inode_init_once(struct inode *);
extern void address_space_init_once(struct address_space *mapping);
Historically we have waited for filesystem specific heuristics to attempt to guess when a block device is gone. Sometimes this works, but in other cases the system can hang waiting for the fs to trigger its shutdown protocol. The initial motivation for this investigation was to prevent DAX mappings (direct mmap access to persistent memory) from leaking past the lifetime of the hosting block device. However, Dave points out that these shutdown operations are needed in other scenarios. Quoting Dave: For example, if we detect a free space corruption during allocation, it is not safe to trust *any active mapping* because we can't trust that we having handed out the same block to multiple owners. Hence on such a filesystem shutdown, we have to prevent any new DAX mapping from occurring and invalidate all existing mappings as we cannot allow userspace to modify any data or metadata until we've resolved the corruption situation. Cc: Jan Kara <jack@suse.com> Cc: Jens Axboe <axboe@fb.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Suggested-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- block/genhd.c | 7 +++++-- fs/block_dev.c | 19 +++++++++++++++++++ fs/inode.c | 28 ++++++++++++++++++++++++++++ include/linux/fs.h | 2 ++ 4 files changed, 54 insertions(+), 2 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html