ext4: Don't look at buffer_heads outside i_size.
Buffer heads outside i_size will be unmapped. So when we
are doing "walk_page_buffers" limit ourself to i_size.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Josef Bacik <jbacik@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
----
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index ff2afc1..b87b68c 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2578,7 +2578,7 @@
* all are mapped and non delay. We don't want to
* do block allocation here.
*/
- ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
+ ret = block_prepare_write(page, 0, len,
noalloc_get_block_write);
if (!ret) {
page_bufs = page_buffers(page);
@@ -2600,7 +2600,7 @@
return 0;
}
/* now mark the buffer_heads as dirty and uptodate */
- block_commit_write(page, 0, PAGE_CACHE_SIZE);
+ block_commit_write(page, 0, len);
}
if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
@@ -3246,6 +3246,8 @@
static int __ext4_journalled_writepage(struct page *page,
struct writeback_control *wbc)
{
+ loff_t size;
+ unsigned int len;
struct address_space *mapping = page->mapping;
struct inode *inode = mapping->host;
struct buffer_head *page_bufs;
@@ -3253,14 +3255,17 @@
int ret = 0;
int err;
- ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
- noalloc_get_block_write);
+ size = i_size_read(inode);
+ if (page->index == size >> PAGE_CACHE_SHIFT)
+ len = size & ~PAGE_CACHE_MASK;
+ else
+ len = PAGE_CACHE_SIZE;
+ ret = block_prepare_write(page, 0, len, noalloc_get_block_write);
if (ret != 0)
goto out_unlock;
page_bufs = page_buffers(page);
- walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, NULL,
- bget_one);
+ walk_page_buffers(handle, page_bufs, 0, len, NULL, bget_one);
/* As soon as we unlock the page, it can go away, but we have
* references to buffers so we are safe */
unlock_page(page);
@@ -3271,19 +3276,18 @@
goto out;
}
- ret = walk_page_buffers(handle, page_bufs, 0,
- PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
+ ret = walk_page_buffers(handle, page_bufs, 0, len, NULL,
+ do_journal_get_write_access);
- err = walk_page_buffers(handle, page_bufs, 0,
- PAGE_CACHE_SIZE, NULL, write_end_fn);
+ err = walk_page_buffers(handle, page_bufs, 0, len, NULL,
+ write_end_fn);
if (ret == 0)
ret = err;
err = ext4_journal_stop(handle);
if (!ret)
ret = err;
- walk_page_buffers(handle, page_bufs, 0,
- PAGE_CACHE_SIZE, NULL, bput_one);
+ walk_page_buffers(handle, page_bufs, 0, len, NULL, bput_one);
EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
goto out;