invalidate_mapping_pages(): add cond_resched

invalidate_mapping_pages() can sometimes take a long time (millions of pages
to free).  Long enough for the softlockup detector to trigger.

We used to have a cond_resched() in there but I took it out because the
drop_caches code calls invalidate_mapping_pages() under inode_lock.

The patch adds a nasty flag and puts the cond_resched() back.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4f0b3bf5983c..51c938a71dec 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1610,6 +1610,9 @@ extern int __invalidate_device(struct block_device *);
 extern int invalidate_partition(struct gendisk *, int);
 #endif
 extern int invalidate_inodes(struct super_block *);
+unsigned long __invalidate_mapping_pages(struct address_space *mapping,
+                                        pgoff_t start, pgoff_t end,
+                                        bool be_atomic);
 unsigned long invalidate_mapping_pages(struct address_space *mapping,
                                         pgoff_t start, pgoff_t end);