[PATCH v5 09/10] ext4: move out inode_lock into ext4_fallocate()

[Zhang Yi]

From: Zhang Yi <yi.zhang@xxxxxxxxxx>

Currently, all five sub-functions of ext4_fallocate() acquire the
inode's i_rwsem at the beginning and release it before exiting. This
process can be simplified by factoring out the management of i_rwsem
into the ext4_fallocate() function.

Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Reviewed-by: Ojaswin Mujoo <ojaswin@xxxxxxxxxxxxx>
---
 fs/ext4/extents.c | 90 +++++++++++++++--------------------------------
 fs/ext4/inode.c   | 13 +++----
 2 files changed, 33 insertions(+), 70 deletions(-)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index a8bbbf8a9950..85f0de1abe78 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4578,23 +4578,18 @@ static long ext4_zero_range(struct file *file, loff_t offset,
 	int ret, flags, credits;
 
 	trace_ext4_zero_range(inode, offset, len, mode);
+	WARN_ON_ONCE(!inode_is_locked(inode));
 
-	inode_lock(inode);
-
-	/*
-	 * Indirect files do not support unwritten extents
-	 */
-	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
-		ret = -EOPNOTSUPP;
-		goto out;
-	}
+	/* Indirect files do not support unwritten extents */
+	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
+		return -EOPNOTSUPP;
 
 	if (!(mode & FALLOC_FL_KEEP_SIZE) &&
 	    (end > inode->i_size || end > EXT4_I(inode)->i_disksize)) {
 		new_size = end;
 		ret = inode_newsize_ok(inode, new_size);
 		if (ret)
-			goto out;
+			return ret;
 	}
 
 	/* Wait all existing dio workers, newcomers will block on i_rwsem */
@@ -4602,7 +4597,7 @@ static long ext4_zero_range(struct file *file, loff_t offset,
 
 	ret = file_modified(file);
 	if (ret)
-		goto out;
+		return ret;
 
 	/*
 	 * Prevent page faults from reinstantiating pages we have released
@@ -4684,8 +4679,6 @@ static long ext4_zero_range(struct file *file, loff_t offset,
 	ext4_journal_stop(handle);
 out_invalidate_lock:
 	filemap_invalidate_unlock(mapping);
-out:
-	inode_unlock(inode);
 	return ret;
 }
 
@@ -4699,12 +4692,11 @@ static long ext4_do_fallocate(struct file *file, loff_t offset,
 	int ret;
 
 	trace_ext4_fallocate_enter(inode, offset, len, mode);
+	WARN_ON_ONCE(!inode_is_locked(inode));
 
 	start_lblk = offset >> inode->i_blkbits;
 	len_lblk = EXT4_MAX_BLOCKS(len, offset, inode->i_blkbits);
 
-	inode_lock(inode);
-
 	/* We only support preallocation for extent-based files only. */
 	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
 		ret = -EOPNOTSUPP;
@@ -4736,7 +4728,6 @@ static long ext4_do_fallocate(struct file *file, loff_t offset,
 					EXT4_I(inode)->i_sync_tid);
 	}
 out:
-	inode_unlock(inode);
 	trace_ext4_fallocate_exit(inode, offset, len_lblk, ret);
 	return ret;
 }
@@ -4771,9 +4762,8 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 
 	inode_lock(inode);
 	ret = ext4_convert_inline_data(inode);
-	inode_unlock(inode);
 	if (ret)
-		return ret;
+		goto out_inode_lock;
 
 	if (mode & FALLOC_FL_PUNCH_HOLE)
 		ret = ext4_punch_hole(file, offset, len);
@@ -4785,7 +4775,8 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 		ret = ext4_zero_range(file, offset, len, mode);
 	else
 		ret = ext4_do_fallocate(file, offset, len, mode);
-
+out_inode_lock:
+	inode_unlock(inode);
 	return ret;
 }
 
@@ -5295,36 +5286,27 @@ static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len)
 	int ret;
 
 	trace_ext4_collapse_range(inode, offset, len);
-
-	inode_lock(inode);
+	WARN_ON_ONCE(!inode_is_locked(inode));
 
 	/* Currently just for extent based files */
-	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
-		ret = -EOPNOTSUPP;
-		goto out;
-	}
-
+	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+		return -EOPNOTSUPP;
 	/* Collapse range works only on fs cluster size aligned regions. */
-	if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb))) {
-		ret = -EINVAL;
-		goto out;
-	}
-
+	if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
+		return -EINVAL;
 	/*
 	 * There is no need to overlap collapse range with EOF, in which case
 	 * it is effectively a truncate operation
 	 */
-	if (end >= inode->i_size) {
-		ret = -EINVAL;
-		goto out;
-	}
+	if (end >= inode->i_size)
+		return -EINVAL;
 
 	/* Wait for existing dio to complete */
 	inode_dio_wait(inode);
 
 	ret = file_modified(file);
 	if (ret)
-		goto out;
+		return ret;
 
 	/*
 	 * Prevent page faults from reinstantiating pages we have released from
@@ -5399,8 +5381,6 @@ static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len)
 	ext4_journal_stop(handle);
 out_invalidate_lock:
 	filemap_invalidate_unlock(mapping);
-out:
-	inode_unlock(inode);
 	return ret;
 }
 
@@ -5426,39 +5406,27 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
 	loff_t start;
 
 	trace_ext4_insert_range(inode, offset, len);
-
-	inode_lock(inode);
+	WARN_ON_ONCE(!inode_is_locked(inode));
 
 	/* Currently just for extent based files */
-	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
-		ret = -EOPNOTSUPP;
-		goto out;
-	}
-
+	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+		return -EOPNOTSUPP;
 	/* Insert range works only on fs cluster size aligned regions. */
-	if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb))) {
-		ret = -EINVAL;
-		goto out;
-	}
-
+	if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
+		return -EINVAL;
 	/* Offset must be less than i_size */
-	if (offset >= inode->i_size) {
-		ret = -EINVAL;
-		goto out;
-	}
-
+	if (offset >= inode->i_size)
+		return -EINVAL;
 	/* Check whether the maximum file size would be exceeded */
-	if (len > inode->i_sb->s_maxbytes - inode->i_size) {
-		ret = -EFBIG;
-		goto out;
-	}
+	if (len > inode->i_sb->s_maxbytes - inode->i_size)
+		return -EFBIG;
 
 	/* Wait for existing dio to complete */
 	inode_dio_wait(inode);
 
 	ret = file_modified(file);
 	if (ret)
-		goto out;
+		return ret;
 
 	/*
 	 * Prevent page faults from reinstantiating pages we have released from
@@ -5559,8 +5527,6 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
 	ext4_journal_stop(handle);
 out_invalidate_lock:
 	filemap_invalidate_unlock(mapping);
-out:
-	inode_unlock(inode);
 	return ret;
 }
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 372c7145e7c2..a05507ee7c5e 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4015,15 +4015,14 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
 	loff_t end = offset + length;
 	handle_t *handle;
 	unsigned int credits;
-	int ret = 0;
+	int ret;
 
 	trace_ext4_punch_hole(inode, offset, length, 0);
-
-	inode_lock(inode);
+	WARN_ON_ONCE(!inode_is_locked(inode));
 
 	/* No need to punch hole beyond i_size */
 	if (offset >= inode->i_size)
-		goto out;
+		return 0;
 
 	/*
 	 * If the hole extends beyond i_size, set the hole to end after
@@ -4043,7 +4042,7 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
 	if (!IS_ALIGNED(offset | end, sb->s_blocksize)) {
 		ret = ext4_inode_attach_jinode(inode);
 		if (ret < 0)
-			goto out;
+			return ret;
 	}
 
 	/* Wait all existing dio workers, newcomers will block on i_rwsem */
@@ -4051,7 +4050,7 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
 
 	ret = file_modified(file);
 	if (ret)
-		goto out;
+		return ret;
 
 	/*
 	 * Prevent page faults from reinstantiating pages we have released from
@@ -4127,8 +4126,6 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
 	ext4_journal_stop(handle);
 out_invalidate_lock:
 	filemap_invalidate_unlock(mapping);
-out:
-	inode_unlock(inode);
 	return ret;
 }
 
-- 
2.46.1