fat: remove i_alloc_sem abuse
Add a new rw_semaphore to protect bmap against truncate. Previous
i_alloc_sem was abused for this, but it's going away in this series.
Note that we can't simply use i_mutex, given that the swapon code
calls ->bmap under it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 7018e1d..a4a3a3c 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -429,8 +429,10 @@
}
if (attr->ia_valid & ATTR_SIZE) {
+ down_write(&MSDOS_I(inode)->truncate_lock);
truncate_setsize(inode, attr->ia_size);
fat_truncate_blocks(inode, attr->ia_size);
+ up_write(&MSDOS_I(inode)->truncate_lock);
}
setattr_copy(inode, attr);