linux-ext4 - [PATCH v4 1/3] ext4: Add missing locking around iomap_seek

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Date:   Fri,  7 Jul 2017 23:27:59 +0200
From:   Andreas Gruenbacher <agruenba@...hat.com>
To:     Christoph Hellwig <hch@....de>
Cc:     Andreas Gruenbacher <agruenba@...hat.com>, Jan Kara <jack@...e.cz>,
        linux-fsdevel@...r.kernel.org, linux-xfs@...r.kernel.org,
        linux-ext4@...r.kernel.org
Subject: [PATCH v4 1/3] ext4: Add missing locking around iomap_seek_{hole,data}

Add back the inode locking that "ext4: Switch to iomap for SEEK_HOLE /
SEEK_DATA" blew away.  We can use inode_lock_shared instead of
inode_lock instead, though.

Signed-off-by: Andreas Gruenbacher <agruenba@...hat.com>
---
 fs/ext4/file.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 02bbf2c..699a676 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -459,10 +459,14 @@ loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
 		return generic_file_llseek_size(file, offset, whence,
 						maxbytes, i_size_read(inode));
 	case SEEK_HOLE:
+		inode_lock_shared(inode);
 		offset = iomap_seek_hole(inode, offset, &ext4_iomap_ops);
+		inode_unlock_shared(inode);
 		break;
 	case SEEK_DATA:
+		inode_lock_shared(inode);
 		offset = iomap_seek_data(inode, offset, &ext4_iomap_ops);
+		inode_unlock_shared(inode);
 		break;
 	}
 
-- 
2.7.5