Merge tag 'for-linus' of git://github.com/prasad-joshi/logfs_upstream

Pull LogFS bugfixes from Prasad Joshi:

- "logfs: query block device for number of pages to send with bio"

This BUG was found when LogFS was used on KVM. The patch fixes
the problem by asking for underlaying block device the number
of pages to send with each BIO.

- "logfs: maintain the ordering of meta-inode destruction"

LogFS maintains file system meta-data in special inodes. These
inodes are releated to each other, therefore they must be
destroyed in a proper order.

- "logfs: initialize the number of iovecs in bio"

LogFS used to panic when it was created on an encrypted LVM
volume. The patch fixes the problem by properly initializing
the BIO.

Plus a couple more:
- logfs: create a pagecache page if it is not present
- logfs: destroy the reserved inodes while unmounting

* tag 'for-linus' of git://github.com/prasad-joshi/logfs_upstream:
logfs: query block device for number of pages to send with bio
logfs: maintain the ordering of meta-inode destruction
logfs: create a pagecache page if it is not present
logfs: initialize the number of iovecs in bio
logfs: destroy the reserved inodes while unmounting

fs/logfs/dev_bdev.c

···
 	struct completion complete;
 
 	bio_init(&bio);
+	bio.bi_max_vecs = 1;
 	bio.bi_io_vec = &bio_vec;
 	bio_vec.bv_page = page;
 	bio_vec.bv_len = PAGE_SIZE;
···
 	struct address_space *mapping = super->s_mapping_inode->i_mapping;
 	struct bio *bio;
 	struct page *page;
-	struct request_queue *q = bdev_get_queue(sb->s_bdev);
-	unsigned int max_pages = queue_max_hw_sectors(q) >> (PAGE_SHIFT - 9);
+	unsigned int max_pages;
 	int i;
 
-	if (max_pages > BIO_MAX_PAGES)
-		max_pages = BIO_MAX_PAGES;
+	max_pages = min(nr_pages, (size_t) bio_get_nr_vecs(super->s_bdev));
+
 	bio = bio_alloc(GFP_NOFS, max_pages);
 	BUG_ON(!bio);
 
···
 {
 	struct logfs_super *super = logfs_super(sb);
 	struct bio *bio;
-	struct request_queue *q = bdev_get_queue(sb->s_bdev);
-	unsigned int max_pages = queue_max_hw_sectors(q) >> (PAGE_SHIFT - 9);
+	unsigned int max_pages;
 	int i;
 
-	if (max_pages > BIO_MAX_PAGES)
-		max_pages = BIO_MAX_PAGES;
+	max_pages = min(nr_pages, (size_t) bio_get_nr_vecs(super->s_bdev));
+
 	bio = bio_alloc(GFP_NOFS, max_pages);
 	BUG_ON(!bio);
 

fs/logfs/inode.c

···
 	call_rcu(&inode->i_rcu, logfs_i_callback);
 }
 
+static void __logfs_destroy_meta_inode(struct inode *inode)
+{
+	struct logfs_inode *li = logfs_inode(inode);
+	BUG_ON(li->li_block);
+	call_rcu(&inode->i_rcu, logfs_i_callback);
+}
+
 static void logfs_destroy_inode(struct inode *inode)
 {
 	struct logfs_inode *li = logfs_inode(inode);
+
+	if (inode->i_ino < LOGFS_RESERVED_INOS) {
+		/*
+		 * The reserved inodes are never destroyed unless we are in
+		 * unmont path.
+		 */
+		__logfs_destroy_meta_inode(inode);
+		return;
+	}
 
 	BUG_ON(list_empty(&li->li_freeing_list));
 	spin_lock(&logfs_inode_lock);
···
 {
 	struct logfs_super *super = logfs_super(sb);
 	/* kill the meta-inodes */
-	iput(super->s_master_inode);
 	iput(super->s_segfile_inode);
+	iput(super->s_master_inode);
 	iput(super->s_mapping_inode);
 }
 

fs/logfs/journal.c

···
 	index = ofs >> PAGE_SHIFT;
 	page_ofs = ofs & (PAGE_SIZE - 1);
 
-	page = find_lock_page(mapping, index);
+	page = find_or_create_page(mapping, index, GFP_NOFS);
 	BUG_ON(!page);
 	memcpy(wbuf, page_address(page) + page_ofs, super->s_writesize);
 	unlock_page(page);

fs/logfs/readwrite.c

···
 		return;
 	}
 
-	BUG_ON(inode->i_ino < LOGFS_RESERVED_INOS);
 	page = inode_to_page(inode);
 	BUG_ON(!page); /* FIXME: Use emergency page */
 	logfs_put_write_page(page);

fs/logfs/segment.c

···
 
 static void map_invalidatepage(struct page *page, unsigned long l)
 {
-	BUG();
+	return;
 }
 
 static int map_releasepage(struct page *page, gfp_t g)