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

Pull ext4 updates from Ted Ts'o:
 "In addition to bug fixes and cleanups, there are two new features for
  ext4 in 5.14:

   - Allow applications to poll on changes to
     /sys/fs/ext4/*/errors_count

   - Add the ioctl EXT4_IOC_CHECKPOINT which allows the journal to be
     checkpointed, truncated and discarded or zero'ed"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (32 commits)
  jbd2: export jbd2_journal_[un]register_shrinker()
  ext4: notify sysfs on errors_count value change
  fs: remove bdev_try_to_free_page callback
  ext4: remove bdev_try_to_free_page() callback
  jbd2: simplify journal_clean_one_cp_list()
  jbd2,ext4: add a shrinker to release checkpointed buffers
  jbd2: remove redundant buffer io error checks
  jbd2: don't abort the journal when freeing buffers
  jbd2: ensure abort the journal if detect IO error when writing original buffer back
  jbd2: remove the out label in __jbd2_journal_remove_checkpoint()
  ext4: no need to verify new add extent block
  jbd2: clean up misleading comments for jbd2_fc_release_bufs
  ext4: add check to prevent attempting to resize an fs with sparse_super2
  ext4: consolidate checks for resize of bigalloc into ext4_resize_begin
  ext4: remove duplicate definition of ext4_xattr_ibody_inline_set()
  ext4: fsmap: fix the block/inode bitmap comment
  ext4: fix comment for s_hash_unsigned
  ext4: use local variable ei instead of EXT4_I() macro
  ext4: fix avefreec in find_group_orlov
  ext4: correct the cache_nr in tracepoint ext4_es_shrink_exit
  ...

2 files changed, 42 insertions, 2 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index fad6663cd1b0..02bf57e6f6e2 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2171,7 +2171,6 @@ struct super_operations {
 	ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
 	struct dquot **(*get_dquots)(struct inode *);
 #endif
-	int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
 	long (*nr_cached_objects)(struct super_block *,
 				  struct shrink_control *);
 	long (*free_cached_objects)(struct super_block *,
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index db0e1920cb12..6cc035321562 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -780,6 +780,11 @@ struct journal_s
 	unsigned long		j_flags;
 
 	/**
+	 * @j_atomic_flags: Atomic journaling state flags.
+	 */
+	unsigned long		j_atomic_flags;
+
+	/**
 	 * @j_errno:
 	 *
 	 * Is there an outstanding uncleared error on the journal (from a prior
@@ -905,6 +910,29 @@ struct journal_s
 	struct buffer_head	*j_chkpt_bhs[JBD2_NR_BATCH];
 
 	/**
+	 * @j_shrinker:
+	 *
+	 * Journal head shrinker, reclaim buffer's journal head which
+	 * has been written back.
+	 */
+	struct shrinker		j_shrinker;
+
+	/**
+	 * @j_jh_shrink_count:
+	 *
+	 * Number of journal buffers on the checkpoint list. [j_list_lock]
+	 */
+	struct percpu_counter	j_jh_shrink_count;
+
+	/**
+	 * @j_shrink_transaction:
+	 *
+	 * Record next transaction will shrink on the checkpoint list.
+	 * [j_list_lock]
+	 */
+	transaction_t		*j_shrink_transaction;
+
+	/**
 	 * @j_head:
 	 *
 	 * Journal head: identifies the first unused block in the journal.
@@ -1370,6 +1398,16 @@ JBD2_FEATURE_INCOMPAT_FUNCS(fast_commit,	FAST_COMMIT)
 						 * mode */
 #define JBD2_FAST_COMMIT_ONGOING	0x100	/* Fast commit is ongoing */
 #define JBD2_FULL_COMMIT_ONGOING	0x200	/* Full commit is ongoing */
+#define JBD2_JOURNAL_FLUSH_DISCARD	0x0001
+#define JBD2_JOURNAL_FLUSH_ZEROOUT	0x0002
+#define JBD2_JOURNAL_FLUSH_VALID	(JBD2_JOURNAL_FLUSH_DISCARD | \
+					JBD2_JOURNAL_FLUSH_ZEROOUT)
+
+/*
+ * Journal atomic flag definitions
+ */
+#define JBD2_CHECKPOINT_IO_ERROR	0x001	/* Detect io error while writing
+						 * buffer back to disk */
 
 /*
  * Function declarations for the journaling transaction and buffer
@@ -1407,6 +1445,7 @@ extern void jbd2_journal_commit_transaction(journal_t *);
 
 /* Checkpoint list management */
 void __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy);
+unsigned long jbd2_journal_shrink_checkpoint_list(journal_t *journal, unsigned long *nr_to_scan);
 int __jbd2_journal_remove_checkpoint(struct journal_head *);
 void jbd2_journal_destroy_checkpoint(journal_t *journal);
 void __jbd2_journal_insert_checkpoint(struct journal_head *, transaction_t *);
@@ -1500,7 +1539,7 @@ extern int	 jbd2_journal_invalidatepage(journal_t *,
 				struct page *, unsigned int, unsigned int);
 extern int	 jbd2_journal_try_to_free_buffers(journal_t *journal, struct page *page);
 extern int	 jbd2_journal_stop(handle_t *);
-extern int	 jbd2_journal_flush (journal_t *);
+extern int	 jbd2_journal_flush(journal_t *journal, unsigned int flags);
 extern void	 jbd2_journal_lock_updates (journal_t *);
 extern void	 jbd2_journal_unlock_updates (journal_t *);
 
@@ -1517,6 +1556,8 @@ extern int	   jbd2_journal_set_features
 		   (journal_t *, unsigned long, unsigned long, unsigned long);
 extern void	   jbd2_journal_clear_features
 		   (journal_t *, unsigned long, unsigned long, unsigned long);
+extern int	   jbd2_journal_register_shrinker(journal_t *journal);
+extern void	   jbd2_journal_unregister_shrinker(journal_t *journal);
 extern int	   jbd2_journal_load       (journal_t *journal);
 extern int	   jbd2_journal_destroy    (journal_t *);
 extern int	   jbd2_journal_recover    (journal_t *journal);