[PATCH] fat: hold truncate_lock in fat_write_failed()

[Matheus Alves de Almeida]

The current fat_write_failed() implementation calls into
fat_truncate_blocks() without holding truncate_lock. Make it so it is
held exclusive while truncating.

Fixes: 459f6ed3b8c7 ("fat: convert to use the new truncate convention.")
Signed-off-by: Matheus Alves de Almeida <matheus.aalmeida@xxxxxxxxxxxx>
---
 fs/fat/inode.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 141276fcf8db..2a16ed415631 100644
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -216,7 +216,9 @@ static void fat_write_failed(struct address_space *mapping, loff_t to)
 
 	if (to > inode->i_size) {
 		truncate_pagecache(inode, inode->i_size);
+		down_write(&MSDOS_I(inode)->truncate_lock);
 		fat_truncate_blocks(inode, inode->i_size);
+		up_write(&MSDOS_I(inode)->truncate_lock);
 	}
 }
 
-- 
2.43.0