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Date: Wed, 21 May 2008 23:14:15 +0530
From: "Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
To: cmm@...ibm.com, tytso@....edu, sandeen@...hat.com
Cc: linux-ext4@...r.kernel.org,
"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
Subject: [PATCH] ext4: Add validation to jbd lock inversion patch and split and writepage
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@...ux.vnet.ibm.com>
---
fs/ext4/inode.c | 180 ++++++++++++++++++++++++++++++++++++++++++++++--------
1 files changed, 153 insertions(+), 27 deletions(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index d099f55..26a7df3 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1479,6 +1479,11 @@ static int jbd2_journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
return 0;
}
+static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
+{
+ return !buffer_mapped(bh);
+}
+
/*
* Note that we don't need to start a transaction unless we're journaling
* data because we should have holes filled from ext4_page_mkwrite(). If
@@ -1531,18 +1536,26 @@ static int jbd2_journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
static int __ext4_ordered_writepage(struct page *page,
struct writeback_control *wbc)
{
- struct inode *inode = page->mapping->host;
- struct buffer_head *page_bufs;
+ int ret = 0, err;
+ unsigned long len;
handle_t *handle = NULL;
- int ret = 0;
- int err;
+ struct buffer_head *page_bufs;
+ struct inode *inode = page->mapping->host;
+ loff_t size = i_size_read(inode);
- if (!page_has_buffers(page)) {
- create_empty_buffers(page, inode->i_sb->s_blocksize,
- (1 << BH_Dirty)|(1 << BH_Uptodate));
- }
page_bufs = page_buffers(page);
- walk_page_buffers(handle, page_bufs, 0,
+ if (page->index == size >> PAGE_CACHE_SHIFT)
+ len = size & ~PAGE_CACHE_MASK;
+ else
+ len = PAGE_CACHE_SIZE;
+
+ if (walk_page_buffers(NULL, page_bufs, 0,
+ len, NULL, ext4_bh_unmapped)) {
+ printk(KERN_CRIT "%s called with unmapped buffer\n",
+ __func__);
+ BUG();
+ }
+ walk_page_buffers(NULL, page_bufs, 0,
PAGE_CACHE_SIZE, NULL, bget_one);
ret = block_write_full_page(page, ext4_get_block, wbc);
@@ -1574,8 +1587,8 @@ static int __ext4_ordered_writepage(struct page *page,
ret = err;
}
out_put:
- walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, NULL,
- bput_one);
+ walk_page_buffers(handle, page_bufs, 0,
+ PAGE_CACHE_SIZE, NULL, bput_one);
return ret;
}
@@ -1583,7 +1596,7 @@ static int ext4_ordered_writepage(struct page *page,
struct writeback_control *wbc)
{
J_ASSERT(PageLocked(page));
-
+ BUG_ON(!page_has_buffers(page));
/*
* We give up here if we're reentered, because it might be for a
* different filesystem.
@@ -1599,18 +1612,34 @@ static int ext4_ordered_writepage(struct page *page,
static int __ext4_writeback_writepage(struct page *page,
struct writeback_control *wbc)
{
+ unsigned long len;
+ struct buffer_head *page_bufs;
struct inode *inode = page->mapping->host;
+ loff_t size = i_size_read(inode);
+ page_bufs = page_buffers(page);
+ if (page->index == size >> PAGE_CACHE_SHIFT)
+ len = size & ~PAGE_CACHE_MASK;
+ else
+ len = PAGE_CACHE_SIZE;
+
+ if (walk_page_buffers(NULL, page_bufs, 0,
+ len, NULL, ext4_bh_unmapped)) {
+ printk(KERN_CRIT "%s called with unmapped buffer\n",
+ __func__);
+ BUG();
+ }
if (test_opt(inode->i_sb, NOBH))
return nobh_writepage(page, ext4_get_block, wbc);
else
return block_write_full_page(page, ext4_get_block, wbc);
}
-
static int ext4_writeback_writepage(struct page *page,
struct writeback_control *wbc)
{
+ BUG_ON(!page_has_buffers(page));
+
if (!ext4_journal_current_handle())
return __ext4_writeback_writepage(page, wbc);
@@ -1622,18 +1651,31 @@ static int ext4_writeback_writepage(struct page *page,
static int __ext4_journalled_writepage(struct page *page,
struct writeback_control *wbc)
{
+ int ret = 0, err;
+ unsigned long len;
+ handle_t *handle = NULL;
struct address_space *mapping = page->mapping;
struct inode *inode = mapping->host;
struct buffer_head *page_bufs;
- handle_t *handle = NULL;
- int ret = 0;
- int err;
+ loff_t size = i_size_read(inode);
+
+ page_bufs = page_buffers(page);
+ if (page->index == size >> PAGE_CACHE_SHIFT)
+ len = size & ~PAGE_CACHE_MASK;
+ else
+ len = PAGE_CACHE_SIZE;
+ if (walk_page_buffers(NULL, page_bufs, 0,
+ len, NULL, ext4_bh_unmapped)) {
+ printk(KERN_CRIT "%s called with unmapped buffer\n",
+ __func__);
+ BUG();
+ }
+ /* FIXME!! do we need to call prepare_write for a mapped buffer */
ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE, ext4_get_block);
if (ret != 0)
goto out_unlock;
- page_bufs = page_buffers(page);
walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, NULL,
bget_one);
/* As soon as we unlock the page, it can go away, but we have
@@ -1671,14 +1713,13 @@ static int __ext4_journalled_writepage(struct page *page,
static int ext4_journalled_writepage(struct page *page,
struct writeback_control *wbc)
{
+ BUG_ON(!page_has_buffers(page));
+
if (ext4_journal_current_handle())
goto no_write;
- if (!page_has_buffers(page) || PageChecked(page)) {
- /*
- * It's mmapped pagecache. Add buffers and journal it. There
- * doesn't seem much point in redirtying the page here.
- */
+ if (PageChecked(page)) {
+ /* dirty pages in data=journal mode */
ClearPageChecked(page);
return __ext4_journalled_writepage(page, wbc);
} else {
@@ -3520,9 +3561,94 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
return err;
}
-static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
+static int __ext4_journalled_allocpage(struct page *page,
+ struct writeback_control *wbc)
{
- return !buffer_mapped(bh);
+ int ret = 0, err;
+ handle_t *handle = NULL;
+ struct address_space *mapping = page->mapping;
+ struct inode *inode = mapping->host;
+ struct buffer_head *page_bufs;
+
+ /* if alloc we are called after statring a journal */
+ handle = ext4_journal_current_handle();
+ BUG_ON(!handle);
+
+ ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE, ext4_get_block);
+ if (ret != 0)
+ goto out_unlock;
+
+ /* FIXME!! should we do a bget_one */
+ page_bufs = page_buffers(page);
+ ret = walk_page_buffers(handle, page_bufs, 0,
+ PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
+
+ err = walk_page_buffers(handle, page_bufs, 0,
+ PAGE_CACHE_SIZE, NULL, write_end_fn);
+ if (ret == 0)
+ ret = err;
+ EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
+
+out_unlock:
+ unlock_page(page);
+ return ret;
+}
+
+static int __ext4_ordered_allocpage(struct page *page,
+ struct writeback_control *wbc)
+{
+ int ret = 0;
+ handle_t *handle = NULL;
+ struct buffer_head *page_bufs;
+ struct inode *inode = page->mapping->host;
+
+ /* if alloc we are called after statring a journal */
+ handle = ext4_journal_current_handle();
+ BUG_ON(!handle);
+ if (!page_has_buffers(page)) {
+ create_empty_buffers(page, inode->i_sb->s_blocksize,
+ (1 << BH_Dirty)|(1 << BH_Uptodate));
+ }
+ page_bufs = page_buffers(page);
+ walk_page_buffers(handle, page_bufs, 0,
+ PAGE_CACHE_SIZE, NULL, bget_one);
+
+ ret = block_write_full_page(page, ext4_get_block, wbc);
+
+ /*
+ * The page can become unlocked at any point now, and
+ * truncate can then come in and change things. So we
+ * can't touch *page from now on. But *page_bufs is
+ * safe due to elevated refcount.
+ */
+
+ /*
+ * And attach them to the current transaction. But only if
+ * block_write_full_page() succeeded. Otherwise they are unmapped,
+ * and generally junk.
+ */
+ if (ret == 0) {
+ ret = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
+ NULL, jbd2_journal_dirty_data_fn);
+ }
+ walk_page_buffers(handle, page_bufs, 0,
+ PAGE_CACHE_SIZE, NULL, bput_one);
+ return ret;
+}
+
+static int __ext4_writeback_allocpage(struct page *page,
+ struct writeback_control *wbc)
+{
+ handle_t *handle = NULL;
+ struct inode *inode = page->mapping->host;
+ /* if alloc we are called after statring a journal */
+ handle = ext4_journal_current_handle();
+ BUG_ON(!handle);
+
+ if (test_opt(inode->i_sb, NOBH))
+ return nobh_writepage(page, ext4_get_block, wbc);
+ else
+ return block_write_full_page(page, ext4_get_block, wbc);
}
int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page)
@@ -3578,11 +3704,11 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page)
wbc.range_start = page_offset(page);
wbc.range_end = page_offset(page) + PAGE_CACHE_SIZE;
if (ext4_should_writeback_data(inode))
- ret = __ext4_writeback_writepage(page, &wbc);
+ ret = __ext4_writeback_allocpage(page, &wbc);
else if (ext4_should_order_data(inode))
- ret = __ext4_ordered_writepage(page, &wbc);
+ ret = __ext4_ordered_allocpage(page, &wbc);
else
- ret = __ext4_journalled_writepage(page, &wbc);
+ ret = __ext4_journalled_allocpage(page, &wbc);
/* Page got unlocked in writepage */
err = ext4_journal_stop(handle);
if (!ret)
--
1.5.5.1.211.g65ea3.dirty
--
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