From b767e78a179e5ab30fdbff1686d074ac270471eb Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Thu, 4 Jun 2009 08:06:06 -0400 Subject: [PATCH] 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 Reviewed-by: Josef Bacik Acked-by: Jan Kara Signed-off-by: "Theodore Ts'o" ---- --- fs/ext4/inode.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index ff2afc1909b3..b87b68cd3241 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2578,7 +2578,7 @@ static int ext4_da_writepage(struct page *page, * 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 @@ static int ext4_da_writepage(struct page *page, 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_normal_writepage(struct page *page, 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 @@ static int __ext4_journalled_writepage(struct page *page, 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 @@ static int __ext4_journalled_writepage(struct page *page, 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;