Merge tag 'for_v5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull ext2/udf updates from Jan Kara:
 "Cleanups and fixes for ext2 and one cleanup for udf"

* tag 'for_v5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  ext2: fix empty body warnings when -Wextra is used
  ext2: fix debug reference to ext2_xattr_cache
  udf: udf_sb.h: Replace zero-length array with flexible-array member
  ext2: xattr.h: Replace zero-length array with flexible-array member
  ext2: Silence lockdep warning about reclaim under xattr_sem

Author: torvalds

fs/ext2/xattr.c

@@ -56,6 +56,7 @@
 
 #include <linux/buffer_head.h>
 #include <linux/init.h>
+#include <linux/printk.h>
 #include <linux/slab.h>
 #include <linux/mbcache.h>
 #include <linux/quotaops.h>
@@ -84,8 +85,8 @@
 		printk("\n"); \
 	} while (0)
 #else
-# define ea_idebug(f...)
-# define ea_bdebug(f...)
+# define ea_idebug(inode, f...)	no_printk(f)
+# define ea_bdebug(bh, f...)	no_printk(f)
 #endif
 
 static int ext2_xattr_set2(struct inode *, struct buffer_head *,
@@ -790,7 +791,15 @@ ext2_xattr_delete_inode(struct inode *inode)
 	struct buffer_head *bh = NULL;
 	struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb);
 
-	down_write(&EXT2_I(inode)->xattr_sem);
+	/*
+	 * We are the only ones holding inode reference. The xattr_sem should
+	 * better be unlocked! We could as well just not acquire xattr_sem at
+	 * all but this makes the code more futureproof. OTOH we need trylock
+	 * here to avoid false-positive warning from lockdep about reclaim
+	 * circular dependency.
+	 */
+	if (WARN_ON_ONCE(!down_write_trylock(&EXT2_I(inode)->xattr_sem)))
+		return;
 	if (!EXT2_I(inode)->i_file_acl)
 		goto cleanup;
 
@@ -864,8 +873,7 @@ ext2_xattr_cache_insert(struct mb_cache *cache, struct buffer_head *bh)
 				      true);
 	if (error) {
 		if (error == -EBUSY) {
-			ea_bdebug(bh, "already in cache (%d cache entries)",
-				atomic_read(&ext2_xattr_cache->c_entry_count));
+			ea_bdebug(bh, "already in cache");
 			error = 0;
 		}
 	} else

fs/ext2/xattr.h

@@ -39,7 +39,7 @@ struct ext2_xattr_entry {
 	__le32	e_value_block;	/* disk block attribute is stored on (n/i) */
 	__le32	e_value_size;	/* size of attribute value */
 	__le32	e_hash;		/* hash value of name and value */
-	char	e_name[0];	/* attribute name */
+	char	e_name[];	/* attribute name */
 };
 
 #define EXT2_XATTR_PAD_BITS		2

fs/udf/udf_sb.h

@@ -83,7 +83,7 @@ struct udf_virtual_data {
 struct udf_bitmap {
 	__u32			s_extPosition;
 	int			s_nr_groups;
-	struct buffer_head 	*s_block_bitmap[0];
+	struct buffer_head	*s_block_bitmap[];
 };
 
 struct udf_part_map {