Inorder to check whether the buffer_heads are mapped we need
to hold page lock. Otherwise a reclaim can cleanup the attached
buffer_heads. Instead of taking page lock and check whether
buffer_heads are mapped we let the write_begin/write_end callback
does the equivalent. It does have a performance impact in that we
are doing more work if we the buffer_heads are already mapped.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
---
fs/ext4/inode.c | 6 ------
1 files changed, 0 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index f9c642b..d40b97d 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5281,12 +5281,6 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
else
len = PAGE_CACHE_SIZE;
- if (page_has_buffers(page)) {
- /* return if we have all the buffers mapped */
- if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
- ext4_bh_unmapped))
- goto out_unlock;
- }
/*
* OK, we need to fill the hole... Do write_begin write_end
* to do block allocation/reservation.We are not holding
--
1.6.4.1.174.g32f4c
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
