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

Pull ext4 updates from Ted Ts'o:
 "This merge window saw the the following new featuers added to ext4:

   - Direct I/O via iomap (required the iomap-for-next branch from
     Darrick as a prereq).

   - Support for using dioread-nolock where the block size < page size.

   - Support for encryption for file systems where the block size < page
     size.

   - Rework of journal credits handling so a revoke-heavy workload will
     not cause the journal to run out of space.

   - Replace bit-spinlocks with spinlocks in jbd2

  Also included were some bug fixes and cleanups, mostly to clean up
  corner cases from fuzzed file systems and error path handling"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (59 commits)
  ext4: work around deleting a file with i_nlink == 0 safely
  ext4: add more paranoia checking in ext4_expand_extra_isize handling
  jbd2: make jbd2_handle_buffer_credits() handle reserved handles
  ext4: fix a bug in ext4_wait_for_tail_page_commit
  ext4: bio_alloc with __GFP_DIRECT_RECLAIM never fails
  ext4: code cleanup for get_next_id
  ext4: fix leak of quota reservations
  ext4: remove unused variable warning in parse_options()
  ext4: Enable encryption for subpage-sized blocks
  fs/buffer.c: support fscrypt in block_read_full_page()
  ext4: Add error handling for io_end_vec struct allocation
  jbd2: Fine tune estimate of necessary descriptor blocks
  jbd2: Provide trace event for handle restarts
  ext4: Reserve revoke credits for freed blocks
  jbd2: Make credit checking more strict
  jbd2: Rename h_buffer_credits to h_total_credits
  jbd2: Reserve space for revoke descriptor blocks
  jbd2: Drop jbd2_space_needed()
  jbd2: Account descriptor blocks into t_outstanding_credits
  jbd2: Factor out common parts of stopping and restarting a handle
  ...

1 files changed, 24 insertions, 8 deletions

diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c
index 7c70b08d104c..d3b8cdea5df7 100644
--- a/fs/ext4/ext4_jbd2.c
+++ b/fs/ext4/ext4_jbd2.c
@@ -65,12 +65,14 @@ static int ext4_journal_check_start(struct super_block *sb)
 }
 
 handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
-				  int type, int blocks, int rsv_blocks)
+				  int type, int blocks, int rsv_blocks,
+				  int revoke_creds)
 {
 	journal_t *journal;
 	int err;
 
-	trace_ext4_journal_start(sb, blocks, rsv_blocks, _RET_IP_);
+	trace_ext4_journal_start(sb, blocks, rsv_blocks, revoke_creds,
+				 _RET_IP_);
 	err = ext4_journal_check_start(sb);
 	if (err < 0)
 		return ERR_PTR(err);
@@ -78,8 +80,8 @@ handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line,
 	journal = EXT4_SB(sb)->s_journal;
 	if (!journal)
 		return ext4_get_nojournal();
-	return jbd2__journal_start(journal, blocks, rsv_blocks, GFP_NOFS,
-				   type, line);
+	return jbd2__journal_start(journal, blocks, rsv_blocks, revoke_creds,
+				   GFP_NOFS, type, line);
 }
 
 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
@@ -119,8 +121,8 @@ handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
 		return ext4_get_nojournal();
 
 	sb = handle->h_journal->j_private;
-	trace_ext4_journal_start_reserved(sb, handle->h_buffer_credits,
-					  _RET_IP_);
+	trace_ext4_journal_start_reserved(sb,
+				jbd2_handle_buffer_credits(handle), _RET_IP_);
 	err = ext4_journal_check_start(sb);
 	if (err < 0) {
 		jbd2_journal_free_reserved(handle);
@@ -133,6 +135,19 @@ handle_t *__ext4_journal_start_reserved(handle_t *handle, unsigned int line,
 	return handle;
 }
 
+int __ext4_journal_ensure_credits(handle_t *handle, int check_cred,
+				  int extend_cred, int revoke_cred)
+{
+	if (!ext4_handle_valid(handle))
+		return 0;
+	if (jbd2_handle_buffer_credits(handle) >= check_cred &&
+	    handle->h_revoke_credits >= revoke_cred)
+		return 0;
+	extend_cred = max(0, extend_cred - jbd2_handle_buffer_credits(handle));
+	revoke_cred = max(0, revoke_cred - handle->h_revoke_credits);
+	return ext4_journal_extend(handle, extend_cred, revoke_cred);
+}
+
 static void ext4_journal_abort_handle(const char *caller, unsigned int line,
 				      const char *err_fn,
 				      struct buffer_head *bh,
@@ -278,7 +293,7 @@ int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 				       handle->h_type,
 				       handle->h_line_no,
 				       handle->h_requested_credits,
-				       handle->h_buffer_credits, err);
+				       jbd2_handle_buffer_credits(handle), err);
 				return err;
 			}
 			ext4_error_inode(inode, where, line,
@@ -289,7 +304,8 @@ int __ext4_handle_dirty_metadata(const char *where, unsigned int line,
 					 handle->h_type,
 					 handle->h_line_no,
 					 handle->h_requested_credits,
-					 handle->h_buffer_credits, err);
+					 jbd2_handle_buffer_credits(handle),
+					 err);
 		}
 	} else {
 		if (inode)