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".

1 files changed, 34 insertions, 17 deletions

diff --git a/fs/logfs/readwrite.c b/fs/logfs/readwrite.c
index 2ac4217b7901..4153e65b0148 100644
--- a/fs/logfs/readwrite.c
+++ b/fs/logfs/readwrite.c
@@ -244,8 +244,7 @@ static void preunlock_page(struct super_block *sb, struct page *page, int lock)
  * 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);
 
@@ -260,8 +259,7 @@ static void logfs_get_wblocks(struct super_block *sb, struct page *page,
 	}
 }
 
-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);
 
@@ -424,7 +422,7 @@ static void inode_write_block(struct logfs_block *block)
 	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);
 	}
@@ -560,8 +558,13 @@ static void inode_free_block(struct super_block *sb, struct logfs_block *block)
 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);
 }
 
@@ -650,8 +653,11 @@ static void alloc_data_block(struct inode *inode, struct page *page)
 	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;
 }
 
@@ -1570,11 +1576,15 @@ int logfs_write_buf(struct inode *inode, struct page *page, long flags)
 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);
 }
 
@@ -1623,7 +1633,7 @@ int logfs_rewrite_block(struct inode *inode, u64 bix, u64 ofs,
 			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);
 			}
 		}
 	}
@@ -1873,7 +1883,7 @@ int logfs_truncate(struct inode *inode, u64 target)
 		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);
 	}
 
@@ -1901,8 +1911,11 @@ static void move_page_to_inode(struct inode *inode, struct page *page)
 	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)
@@ -1918,8 +1931,12 @@ 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;
@@ -2106,14 +2123,14 @@ void logfs_set_segment_unreserved(struct super_block *sb, u32 segno, u32 ec)
 			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;
 }