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

There are few important bug fixes for LogFS

* tag 'for-linus' of git://github.com/prasad-joshi/logfs_upstream:
Logfs: Allow NULL block_isbad() methods
logfs: Grow inode in delete path
logfs: Free areas before calling generic_shutdown_super()
logfs: remove useless BUG_ON
MAINTAINERS: Add Prasad Joshi in LogFS maintiners
logfs: Propagate page parameter to __logfs_write_inode
logfs: set superblock shutdown flag after generic sb shutdown
logfs: take write mutex lock during fsync and sync
logfs: Prevent memory corruption
logfs: update page reference count for pined pages

Fix up conflict in fs/logfs/dev_mtd.c due to semantic change in what
"mtd->block_isbad" means in commit f2933e86ad93: "Logfs: Allow NULL
block_isbad() methods" clashing with the abstraction changes in the
commits 7086c19d0742: "mtd: introduce mtd_block_isbad interface" and
d58b27ed58a3: "logfs: do not use 'mtd->block_isbad' directly".

This resolution takes the semantics from commit f2933e86ad93, and just
makes mtd_block_isbad() return zero (false) if the 'block_isbad'
function is NULL. But that also means that now "mtd_can_have_bb()"
always returns 0.

Now, "mtd_block_markbad()" will obviously return an error if the
low-level driver doesn't support bad blocks, so this is somewhat
non-symmetric, but it actually makes sense if a NULL "block_isbad"
function is considered to mean "I assume that all my blocks are always
good".

MAINTAINERS

···
 
 LogFS
 M:	Joern Engel <[e-mail]>
+M:	Prasad Joshi <[e-mail]>
 L:	[e-mail]
 W:	logfs.org
 S:	Maintained

fs/logfs/dir.c

···
 
 static int write_inode(struct inode *inode)
 {
-	return __logfs_write_inode(inode, WF_LOCK);
+	return __logfs_write_inode(inode, NULL, WF_LOCK);
 }
 
 static s64 dir_seek_data(struct inode *inode, s64 pos)

fs/logfs/file.c

···
 		return ret;
 
 	mutex_lock(&inode->i_mutex);
+	logfs_get_wblocks(sb, NULL, WF_LOCK);
 	logfs_write_anchor(sb);
+	logfs_put_wblocks(sb, NULL, WF_LOCK);
 	mutex_unlock(&inode->i_mutex);
 
 	return 0;

fs/logfs/gc.c

···
 	int i, max_dist;
 	struct gc_candidate *cand = NULL, *this;
 
-	max_dist = min(no_free_segments(sb), LOGFS_NO_AREAS);
+	max_dist = min(no_free_segments(sb), LOGFS_NO_AREAS - 1);
 
 	for (i = max_dist; i >= 0; i--) {
 		this = first_in_list(&super->s_low_list[i]);

fs/logfs/inode.c

···
 	if (logfs_inode(inode)->li_flags & LOGFS_IF_STILLBORN)
 		return 0;
 
-	ret = __logfs_write_inode(inode, flags);
+	ret = __logfs_write_inode(inode, NULL, flags);
 	LOGFS_BUG_ON(ret, inode->i_sb);
 	return ret;
 }
···
 
 static int logfs_sync_fs(struct super_block *sb, int wait)
 {
+	logfs_get_wblocks(sb, NULL, WF_LOCK);
 	logfs_write_anchor(sb);
+	logfs_put_wblocks(sb, NULL, WF_LOCK);
 	return 0;
 }
 

fs/logfs/journal.c

···
 	if (len == 0)
 		return logfs_write_header(super, header, 0, type);
 
-	BUG_ON(len > sb->s_blocksize);
 	compr_len = logfs_compress(buf, data, len, sb->s_blocksize);
 	if (compr_len < 0 || type == JE_ANCHOR) {
 		memcpy(data, buf, len);

fs/logfs/logfs.h

···
 void logfs_set_blocks(struct inode *inode, u64 no);
 /* these logically belong into inode.c but actually reside in readwrite.c */
 int logfs_read_inode(struct inode *inode);
-int __logfs_write_inode(struct inode *inode, long flags);
+int __logfs_write_inode(struct inode *inode, struct page *, long flags);
 void logfs_evict_inode(struct inode *inode);
 
 /* journal.c */
···
 		__be64 *array, int page_is_empty);
 int logfs_exist_block(struct inode *inode, u64 bix);
 int get_page_reserve(struct inode *inode, struct page *page);
+void logfs_get_wblocks(struct super_block *sb, struct page *page, int lock);
+void logfs_put_wblocks(struct super_block *sb, struct page *page, int lock);
 extern struct logfs_block_ops indirect_block_ops;
 
 /* segment.c */
···
 void logfs_sync_area(struct logfs_area *area);
 void logfs_sync_segments(struct super_block *sb);
 void freeseg(struct super_block *sb, u32 segno);
+void free_areas(struct super_block *sb);
 
 /* area handling */
 int logfs_init_areas(struct super_block *sb);

fs/logfs/readwrite.c

···
  * is waiting for s_write_mutex.  We annotate this fact by setting PG_pre_locked
  * in addition to PG_locked.
  */
-static void logfs_get_wblocks(struct super_block *sb, struct page *page,
-		int lock)
+void logfs_get_wblocks(struct super_block *sb, struct page *page, int lock)
 {
 	struct logfs_super *super = logfs_super(sb);
 
···
 	}
 }
 
-static void logfs_put_wblocks(struct super_block *sb, struct page *page,
-		int lock)
+void logfs_put_wblocks(struct super_block *sb, struct page *page, int lock)
 {
 	struct logfs_super *super = logfs_super(sb);
 
···
 	if (inode->i_ino == LOGFS_INO_MASTER)
 		logfs_write_anchor(inode->i_sb);
 	else {
-		ret = __logfs_write_inode(inode, 0);
+		ret = __logfs_write_inode(inode, NULL, 0);
 		/* see indirect_write_block comment */
 		BUG_ON(ret);
 	}
···
 static void indirect_free_block(struct super_block *sb,
 		struct logfs_block *block)
 {
-	ClearPagePrivate(block->page);
-	block->page->private = 0;
+	struct page *page = block->page;
+
+	if (PagePrivate(page)) {
+		ClearPagePrivate(page);
+		page_cache_release(page);
+		set_page_private(page, 0);
+	}
 	__free_block(sb, block);
 }
 
···
 	logfs_unpack_index(page->index, &bix, &level);
 	block = __alloc_block(inode->i_sb, inode->i_ino, bix, level);
 	block->page = page;
+
 	SetPagePrivate(page);
-	page->private = (unsigned long)block;
+	page_cache_get(page);
+	set_page_private(page, (unsigned long) block);
+
 	block->ops = &indirect_block_ops;
 }
 
···
 static int __logfs_delete(struct inode *inode, struct page *page)
 {
 	long flags = WF_DELETE;
+	int err;
 
 	inode->i_ctime = inode->i_mtime = CURRENT_TIME;
 
 	if (page->index < I0_BLOCKS)
 		return logfs_write_direct(inode, page, flags);
+	err = grow_inode(inode, page->index, 0);
+	if (err)
+		return err;
 	return logfs_write_rec(inode, page, page->index, 0, flags);
 }
 
···
 			if (inode->i_ino == LOGFS_INO_MASTER)
 				logfs_write_anchor(inode->i_sb);
 			else {
-				err = __logfs_write_inode(inode, flags);
+				err = __logfs_write_inode(inode, page, flags);
 			}
 		}
 	}
···
 		logfs_get_wblocks(sb, NULL, 1);
 		err = __logfs_truncate(inode, size);
 		if (!err)
-			err = __logfs_write_inode(inode, 0);
+			err = __logfs_write_inode(inode, NULL, 0);
 		logfs_put_wblocks(sb, NULL, 1);
 	}
 
···
 	li->li_block = block;
 
 	block->page = NULL;
-	page->private = 0;
-	ClearPagePrivate(page);
+	if (PagePrivate(page)) {
+		ClearPagePrivate(page);
+		page_cache_release(page);
+		set_page_private(page, 0);
+	}
 }
 
 static void move_inode_to_page(struct page *page, struct inode *inode)
···
 	BUG_ON(PagePrivate(page));
 	block->ops = &indirect_block_ops;
 	block->page = page;
-	page->private = (unsigned long)block;
-	SetPagePrivate(page);
+
+	if (!PagePrivate(page)) {
+		SetPagePrivate(page);
+		page_cache_get(page);
+		set_page_private(page, (unsigned long) block);
+	}
 
 	block->inode = NULL;
 	li->li_block = NULL;
···
 			ec_level);
 }
 
-int __logfs_write_inode(struct inode *inode, long flags)
+int __logfs_write_inode(struct inode *inode, struct page *page, long flags)
 {
 	struct super_block *sb = inode->i_sb;
 	int ret;
 
-	logfs_get_wblocks(sb, NULL, flags & WF_LOCK);
+	logfs_get_wblocks(sb, page, flags & WF_LOCK);
 	ret = do_write_inode(inode);
-	logfs_put_wblocks(sb, NULL, flags & WF_LOCK);
+	logfs_put_wblocks(sb, page, flags & WF_LOCK);
 	return ret;
 }
 

fs/logfs/segment.c

···
 		BUG_ON(!page); /* FIXME: reserve a pool */
 		SetPageUptodate(page);
 		memcpy(page_address(page) + offset, buf, copylen);
-		SetPagePrivate(page);
+
+		if (!PagePrivate(page)) {
+			SetPagePrivate(page);
+			page_cache_get(page);
+		}
 		page_cache_release(page);
 
 		buf += copylen;
···
 		page = get_mapping_page(sb, index, 0);
 		BUG_ON(!page); /* FIXME: reserve a pool */
 		memset(page_address(page) + offset, 0xff, len);
-		SetPagePrivate(page);
+		if (!PagePrivate(page)) {
+			SetPagePrivate(page);
+			page_cache_get(page);
+		}
 		page_cache_release(page);
 	}
 }
···
 		BUG_ON(!page); /* FIXME: reserve a pool */
 		SetPageUptodate(page);
 		memset(page_address(page), 0xff, PAGE_CACHE_SIZE);
-		SetPagePrivate(page);
+		if (!PagePrivate(page)) {
+			SetPagePrivate(page);
+			page_cache_get(page);
+		}
 		page_cache_release(page);
 		index++;
 		no_indizes--;
···
 		mempool_free(item, super->s_alias_pool);
 	}
 	block->page = page;
-	SetPagePrivate(page);
-	page->private = (unsigned long)block;
+
+	if (!PagePrivate(page)) {
+		SetPagePrivate(page);
+		page_cache_get(page);
+		set_page_private(page, (unsigned long) block);
+	}
 	block->ops = &indirect_block_ops;
 	initialize_block_counters(page, block, data, 0);
 }
···
 		list_add(&item->list, &block->item_list);
 	}
 	block->page = NULL;
-	ClearPagePrivate(page);
-	page->private = 0;
+
+	if (PagePrivate(page)) {
+		ClearPagePrivate(page);
+		page_cache_release(page);
+		set_page_private(page, 0);
+	}
 	block->ops = &btree_block_ops;
 	err = alias_tree_insert(block->sb, block->ino, block->bix, block->level,
 			block);
···
 		page = find_get_page(mapping, ofs >> PAGE_SHIFT);
 		if (!page)
 			continue;
-		ClearPagePrivate(page);
+		if (PagePrivate(page)) {
+			ClearPagePrivate(page);
+			page_cache_release(page);
+		}
 		page_cache_release(page);
 	}
 }
···
 	kfree(area);
 }
 
+void free_areas(struct super_block *sb)
+{
+	struct logfs_super *super = logfs_super(sb);
+	int i;
+
+	for_each_area(i)
+		free_area(super->s_area[i]);
+	free_area(super->s_journal_area);
+}
+
 static struct logfs_area *alloc_area(struct super_block *sb)
 {
 	struct logfs_area *area;
···
 void logfs_cleanup_areas(struct super_block *sb)
 {
 	struct logfs_super *super = logfs_super(sb);
-	int i;
 
 	btree_grim_visitor128(&super->s_object_alias_tree, 0, kill_alias);
-	for_each_area(i)
-		free_area(super->s_area[i]);
-	free_area(super->s_journal_area);
 }

fs/logfs/super.c

···
 	/* Alias entries slow down mount, so evict as many as possible */
 	sync_filesystem(sb);
 	logfs_write_anchor(sb);
+	free_areas(sb);
 
 	/*
 	 * From this point on alias entries are simply dropped - and any
 	 * writes to the object store are considered bugs.
 	 */
-	super->s_flags |= LOGFS_SB_FLAG_SHUTDOWN;
 	log_super("LogFS: Now in shutdown\n");
 	generic_shutdown_super(sb);
+	super->s_flags |= LOGFS_SB_FLAG_SHUTDOWN;
 
 	BUG_ON(super->s_dirty_used_bytes || super->s_dirty_free_bytes);
 

include/linux/mtd/mtd.h

···
 static inline int mtd_block_isbad(struct mtd_info *mtd, loff_t ofs)
 {
 	if (!mtd->block_isbad)
-		return -EOPNOTSUPP;
+		return 0;
 	return mtd->block_isbad(mtd, ofs);
 }
 
···
 
 static inline int mtd_can_have_bb(const struct mtd_info *mtd)
 {
-	return !!mtd->block_isbad;
+	return 0;
 }
 
 	/* Kernel-side ioctl definitions */