Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 bugfixes from Ted Ts'o:
 "These changes contains a fix for overlayfs interacting with some
  (badly behaved) dentry code in various file systems.  These have been
  reviewed by Al and the respective file system mtinainers and are going
  through the ext4 tree for convenience.

  This also has a few ext4 encryption bug fixes that were discovered in
  Android testing (yes, we will need to get these sync'ed up with the
  fs/crypto code; I'll take care of that).  It also has some bug fixes
  and a change to ignore the legacy quota options to allow for xfstests
  regression testing of ext4's internal quota feature and to be more
  consistent with how xfs handles this case"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: ignore quota mount options if the quota feature is enabled
  ext4 crypto: fix some error handling
  ext4: avoid calling dquot_get_next_id() if quota is not enabled
  ext4: retry block allocation for failed DIO and DAX writes
  ext4: add lockdep annotations for i_data_sem
  ext4: allow readdir()'s of large empty directories to be interrupted
  btrfs: fix crash/invalid memory access on fsync when using overlayfs
  ext4 crypto: use dget_parent() in ext4_d_revalidate()
  ext4: use file_dentry()
  ext4: use dget_parent() in ext4_file_open()
  nfs: use file_dentry()
  fs: add file_dentry()
  ext4 crypto: don't let data integrity writebacks fail with ENOMEM
  ext4: check if in-inode xattr is corrupted in ext4_expand_extra_isize_ea()

1 files changed, 28 insertions, 30 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 4f7043ba4447..981a1fc30eaa 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -763,39 +763,47 @@ int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
 /* Maximum number of blocks we map for direct IO at once. */
 #define DIO_MAX_BLOCKS 4096
 
-static handle_t *start_dio_trans(struct inode *inode,
-				 struct buffer_head *bh_result)
+/*
+ * Get blocks function for the cases that need to start a transaction -
+ * generally difference cases of direct IO and DAX IO. It also handles retries
+ * in case of ENOSPC.
+ */
+static int ext4_get_block_trans(struct inode *inode, sector_t iblock,
+				struct buffer_head *bh_result, int flags)
 {
 	int dio_credits;
+	handle_t *handle;
+	int retries = 0;
+	int ret;
 
 	/* Trim mapping request to maximum we can map at once for DIO */
 	if (bh_result->b_size >> inode->i_blkbits > DIO_MAX_BLOCKS)
 		bh_result->b_size = DIO_MAX_BLOCKS << inode->i_blkbits;
 	dio_credits = ext4_chunk_trans_blocks(inode,
 				      bh_result->b_size >> inode->i_blkbits);
-	return ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits);
+retry:
+	handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits);
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
+
+	ret = _ext4_get_block(inode, iblock, bh_result, flags);
+	ext4_journal_stop(handle);
+
+	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
+		goto retry;
+	return ret;
 }
 
 /* Get block function for DIO reads and writes to inodes without extents */
 int ext4_dio_get_block(struct inode *inode, sector_t iblock,
 		       struct buffer_head *bh, int create)
 {
-	handle_t *handle;
-	int ret;
-
 	/* We don't expect handle for direct IO */
 	WARN_ON_ONCE(ext4_journal_current_handle());
 
-	if (create) {
-		handle = start_dio_trans(inode, bh);
-		if (IS_ERR(handle))
-			return PTR_ERR(handle);
-	}
-	ret = _ext4_get_block(inode, iblock, bh,
-			      create ? EXT4_GET_BLOCKS_CREATE : 0);
-	if (create)
-		ext4_journal_stop(handle);
-	return ret;
+	if (!create)
+		return _ext4_get_block(inode, iblock, bh, 0);
+	return ext4_get_block_trans(inode, iblock, bh, EXT4_GET_BLOCKS_CREATE);
 }
 
 /*
@@ -806,18 +814,13 @@ int ext4_dio_get_block(struct inode *inode, sector_t iblock,
 static int ext4_dio_get_block_unwritten_async(struct inode *inode,
 		sector_t iblock, struct buffer_head *bh_result,	int create)
 {
-	handle_t *handle;
 	int ret;
 
 	/* We don't expect handle for direct IO */
 	WARN_ON_ONCE(ext4_journal_current_handle());
 
-	handle = start_dio_trans(inode, bh_result);
-	if (IS_ERR(handle))
-		return PTR_ERR(handle);
-	ret = _ext4_get_block(inode, iblock, bh_result,
-			      EXT4_GET_BLOCKS_IO_CREATE_EXT);
-	ext4_journal_stop(handle);
+	ret = ext4_get_block_trans(inode, iblock, bh_result,
+				   EXT4_GET_BLOCKS_IO_CREATE_EXT);
 
 	/*
 	 * When doing DIO using unwritten extents, we need io_end to convert
@@ -850,18 +853,13 @@ static int ext4_dio_get_block_unwritten_async(struct inode *inode,
 static int ext4_dio_get_block_unwritten_sync(struct inode *inode,
 		sector_t iblock, struct buffer_head *bh_result,	int create)
 {
-	handle_t *handle;
 	int ret;
 
 	/* We don't expect handle for direct IO */
 	WARN_ON_ONCE(ext4_journal_current_handle());
 
-	handle = start_dio_trans(inode, bh_result);
-	if (IS_ERR(handle))
-		return PTR_ERR(handle);
-	ret = _ext4_get_block(inode, iblock, bh_result,
-			      EXT4_GET_BLOCKS_IO_CREATE_EXT);
-	ext4_journal_stop(handle);
+	ret = ext4_get_block_trans(inode, iblock, bh_result,
+				   EXT4_GET_BLOCKS_IO_CREATE_EXT);
 
 	/*
 	 * Mark inode as having pending DIO writes to unwritten extents.