Miscellaneous ext4 cleanups and bug fixes. Pretty boring this

cycle...
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "Miscellaneous ext4 cleanups and bug fixes. Pretty boring this cycle..."

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: add .kunitconfig fragment to enable ext4-specific tests
  ext: EXT4_KUNIT_TESTS should depend on EXT4_FS instead of selecting it
  ext4: reset retry counter when ext4_alloc_file_blocks() makes progress
  ext4: fix potential htree index checksum corruption
  ext4: factor out htree rep invariant check
  ext4: Change list_for_each* to list_for_each_entry*
  ext4: don't try to processed freed blocks until mballoc is initialized
  ext4: use DEFINE_MUTEX() for mutex lock

fs/ext4/.kunitconfig

@@ -0,0 +1,3 @@
+CONFIG_KUNIT=y
+CONFIG_EXT4_FS=y
+CONFIG_EXT4_KUNIT_TESTS=y

fs/ext4/Kconfig

@@ -103,8 +103,7 @@ config EXT4_DEBUG
 
 config EXT4_KUNIT_TESTS
 	tristate "KUnit tests for ext4" if !KUNIT_ALL_TESTS
-	select EXT4_FS
-	depends on KUNIT
+	depends on EXT4_FS && KUNIT
 	default KUNIT_ALL_TESTS
 	help
 	  This builds the ext4 KUnit tests.

fs/ext4/extents.c

@@ -4382,8 +4382,7 @@ static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
 {
 	struct inode *inode = file_inode(file);
 	handle_t *handle;
-	int ret = 0;
-	int ret2 = 0, ret3 = 0;
+	int ret, ret2 = 0, ret3 = 0;
 	int retries = 0;
 	int depth = 0;
 	struct ext4_map_blocks map;
@@ -4408,7 +4407,7 @@ static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
 	depth = ext_depth(inode);
 
 retry:
-	while (ret >= 0 && len) {
+	while (len) {
 		/*
 		 * Recalculate credits when extent tree depth changes.
 		 */
@@ -4430,9 +4429,13 @@ retry:
 				   inode->i_ino, map.m_lblk,
 				   map.m_len, ret);
 			ext4_mark_inode_dirty(handle, inode);
-			ret2 = ext4_journal_stop(handle);
+			ext4_journal_stop(handle);
 			break;
 		}
+		/*
+		 * allow a full retry cycle for any remaining allocations
+		 */
+		retries = 0;
 		map.m_lblk += ret;
 		map.m_len = len = len - ret;
 		epos = (loff_t)map.m_lblk << inode->i_blkbits;
@@ -4450,11 +4453,8 @@ retry:
 		if (unlikely(ret2))
 			break;
 	}
-	if (ret == -ENOSPC &&
-			ext4_should_retry_alloc(inode->i_sb, &retries)) {
-		ret = 0;
+	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
 		goto retry;
-	}
 
 	return ret > 0 ? ret2 : ret;
 }

fs/ext4/fast_commit.c

@@ -915,13 +915,11 @@ static int ext4_fc_submit_inode_data_all(journal_t *journal)
 	struct super_block *sb = (struct super_block *)(journal->j_private);
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct ext4_inode_info *ei;
-	struct list_head *pos;
 	int ret = 0;
 
 	spin_lock(&sbi->s_fc_lock);
 	ext4_set_mount_flag(sb, EXT4_MF_FC_COMMITTING);
-	list_for_each(pos, &sbi->s_fc_q[FC_Q_MAIN]) {
-		ei = list_entry(pos, struct ext4_inode_info, i_fc_list);
+	list_for_each_entry(ei, &sbi->s_fc_q[FC_Q_MAIN], i_fc_list) {
 		ext4_set_inode_state(&ei->vfs_inode, EXT4_STATE_FC_COMMITTING);
 		while (atomic_read(&ei->i_fc_updates)) {
 			DEFINE_WAIT(wait);
@@ -978,17 +976,15 @@ __releases(&sbi->s_fc_lock)
 {
 	struct super_block *sb = (struct super_block *)(journal->j_private);
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
-	struct ext4_fc_dentry_update *fc_dentry;
+	struct ext4_fc_dentry_update *fc_dentry, *fc_dentry_n;
 	struct inode *inode;
-	struct list_head *pos, *n, *fcd_pos, *fcd_n;
-	struct ext4_inode_info *ei;
+	struct ext4_inode_info *ei, *ei_n;
 	int ret;
 
 	if (list_empty(&sbi->s_fc_dentry_q[FC_Q_MAIN]))
 		return 0;
-	list_for_each_safe(fcd_pos, fcd_n, &sbi->s_fc_dentry_q[FC_Q_MAIN]) {
-		fc_dentry = list_entry(fcd_pos, struct ext4_fc_dentry_update,
-					fcd_list);
+	list_for_each_entry_safe(fc_dentry, fc_dentry_n,
+				 &sbi->s_fc_dentry_q[FC_Q_MAIN], fcd_list) {
 		if (fc_dentry->fcd_op != EXT4_FC_TAG_CREAT) {
 			spin_unlock(&sbi->s_fc_lock);
 			if (!ext4_fc_add_dentry_tlv(
@@ -1004,8 +1000,8 @@ __releases(&sbi->s_fc_lock)
 		}
 
 		inode = NULL;
-		list_for_each_safe(pos, n, &sbi->s_fc_q[FC_Q_MAIN]) {
-			ei = list_entry(pos, struct ext4_inode_info, i_fc_list);
+		list_for_each_entry_safe(ei, ei_n, &sbi->s_fc_q[FC_Q_MAIN],
+					 i_fc_list) {
 			if (ei->vfs_inode.i_ino == fc_dentry->fcd_ino) {
 				inode = &ei->vfs_inode;
 				break;
@@ -1057,7 +1053,6 @@ static int ext4_fc_perform_commit(journal_t *journal)
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct ext4_inode_info *iter;
 	struct ext4_fc_head head;
-	struct list_head *pos;
 	struct inode *inode;
 	struct blk_plug plug;
 	int ret = 0;
@@ -1099,8 +1094,7 @@ static int ext4_fc_perform_commit(journal_t *journal)
 		goto out;
 	}
 
-	list_for_each(pos, &sbi->s_fc_q[FC_Q_MAIN]) {
-		iter = list_entry(pos, struct ext4_inode_info, i_fc_list);
+	list_for_each_entry(iter, &sbi->s_fc_q[FC_Q_MAIN], i_fc_list) {
 		inode = &iter->vfs_inode;
 		if (!ext4_test_inode_state(inode, EXT4_STATE_FC_COMMITTING))
 			continue;
@@ -1226,9 +1220,8 @@ static void ext4_fc_cleanup(journal_t *journal, int full)
 {
 	struct super_block *sb = journal->j_private;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
-	struct ext4_inode_info *iter;
+	struct ext4_inode_info *iter, *iter_n;
 	struct ext4_fc_dentry_update *fc_dentry;
-	struct list_head *pos, *n;
 
 	if (full && sbi->s_fc_bh)
 		sbi->s_fc_bh = NULL;
@@ -1236,8 +1229,8 @@ static void ext4_fc_cleanup(journal_t *journal, int full)
 	jbd2_fc_release_bufs(journal);
 
 	spin_lock(&sbi->s_fc_lock);
-	list_for_each_safe(pos, n, &sbi->s_fc_q[FC_Q_MAIN]) {
-		iter = list_entry(pos, struct ext4_inode_info, i_fc_list);
+	list_for_each_entry_safe(iter, iter_n, &sbi->s_fc_q[FC_Q_MAIN],
+				 i_fc_list) {
 		list_del_init(&iter->i_fc_list);
 		ext4_clear_inode_state(&iter->vfs_inode,
 				       EXT4_STATE_FC_COMMITTING);

fs/ext4/namei.c

@@ -731,6 +731,29 @@ struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 		       (space/bcount)*100/blocksize);
 	return (struct stats) { names, space, bcount};
 }
+
+/*
+ * Linear search cross check
+ */
+static inline void htree_rep_invariant_check(struct dx_entry *at,
+					     struct dx_entry *target,
+					     u32 hash, unsigned int n)
+{
+	while (n--) {
+		dxtrace(printk(KERN_CONT ","));
+		if (dx_get_hash(++at) > hash) {
+			at--;
+			break;
+		}
+	}
+	ASSERT(at == target - 1);
+}
+#else /* DX_DEBUG */
+static inline void htree_rep_invariant_check(struct dx_entry *at,
+					     struct dx_entry *target,
+					     u32 hash, unsigned int n)
+{
+}
 #endif /* DX_DEBUG */
 
 /*
@@ -827,20 +850,7 @@ dx_probe(struct ext4_filename *fname, struct inode *dir,
 				p = m + 1;
 		}
 
-		if (0) { // linear search cross check
-			unsigned n = count - 1;
-			at = entries;
-			while (n--)
-			{
-				dxtrace(printk(KERN_CONT ","));
-				if (dx_get_hash(++at) > hash)
-				{
-					at--;
-					break;
-				}
-			}
-			ASSERT(at == p - 1);
-		}
+		htree_rep_invariant_check(entries, p, hash, count - 1);
 
 		at = p - 1;
 		dxtrace(printk(KERN_CONT " %x->%u\n",
@@ -2401,11 +2411,10 @@ again:
 						   (frame - 1)->bh);
 			if (err)
 				goto journal_error;
-			if (restart) {
-				err = ext4_handle_dirty_dx_node(handle, dir,
-							   frame->bh);
+			err = ext4_handle_dirty_dx_node(handle, dir,
+							frame->bh);
+			if (err)
 				goto journal_error;
-			}
 		} else {
 			struct dx_root *dxroot;
 			memcpy((char *) entries2, (char *) entries,

fs/ext4/super.c

@@ -59,7 +59,7 @@
 #include <trace/events/ext4.h>
 
 static struct ext4_lazy_init *ext4_li_info;
-static struct mutex ext4_li_mtx;
+static DEFINE_MUTEX(ext4_li_mtx);
 static struct ratelimit_state ext4_mount_msg_ratelimit;
 
 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
@@ -4875,7 +4875,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 
 	set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
 
-	sbi->s_journal->j_commit_callback = ext4_journal_commit_callback;
 	sbi->s_journal->j_submit_inode_data_buffers =
 		ext4_journal_submit_inode_data_buffers;
 	sbi->s_journal->j_finish_inode_data_buffers =
@@ -4987,6 +4986,14 @@ no_journal:
 		goto failed_mount5;
 	}
 
+	/*
+	 * We can only set up the journal commit callback once
+	 * mballoc is initialized
+	 */
+	if (sbi->s_journal)
+		sbi->s_journal->j_commit_callback =
+			ext4_journal_commit_callback;
+
 	block = ext4_count_free_clusters(sb);
 	ext4_free_blocks_count_set(sbi->s_es, 
 				   EXT4_C2B(sbi, block));
@@ -6667,7 +6674,6 @@ static int __init ext4_init_fs(void)
 
 	ratelimit_state_init(&ext4_mount_msg_ratelimit, 30 * HZ, 64);
 	ext4_li_info = NULL;
-	mutex_init(&ext4_li_mtx);
 
 	/* Build-time check for flags consistency */
 	ext4_check_flag_values();