to = from + len;
retry:
- page = __grab_cache_page(mapping, index);
- if (!page)
- return -ENOMEM;
- *pagep = page;
-
handle = ext4_journal_start(inode, needed_blocks);
if (IS_ERR(handle)) {
- unlock_page(page);
- page_cache_release(page);
ret = PTR_ERR(handle);
goto out;
}
+ page = __grab_cache_page(mapping, index);
+ if (!page) {
+ ext4_journal_stop(handle);
+ ret = -ENOMEM;
+ goto out;
+ }
+ *pagep = page;
+
ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
ext4_get_block);
}
if (ret) {
- ext4_journal_stop(handle);
unlock_page(page);
+ ext4_journal_stop(handle);
page_cache_release(page);
}
return ext4_journal_dirty_metadata(handle, bh);
}
-/*
- * Generic write_end handler for ordered and writeback ext4 journal modes.
- * We can't use generic_write_end, because that unlocks the page and we need to
- * unlock the page after ext4_journal_stop, but ext4_journal_stop must run
- * after block_write_end.
- */
-static int ext4_generic_write_end(struct file *file,
- struct address_space *mapping,
- loff_t pos, unsigned len, unsigned copied,
- struct page *page, void *fsdata)
-{
- struct inode *inode = file->f_mapping->host;
-
- copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
-
- if (pos+copied > inode->i_size) {
- i_size_write(inode, pos+copied);
- mark_inode_dirty(inode);
- }
-
- return copied;
-}
-
/*
* We need to pick up the new inode size which generic_commit_write gave us
* `file' can be NULL - eg, when called from page_symlink().
struct page *page, void *fsdata)
{
handle_t *handle = ext4_journal_current_handle();
- struct inode *inode = file->f_mapping->host;
+ struct inode *inode = mapping->host;
unsigned from, to;
int ret = 0, ret2;
new_i_size = pos + copied;
if (new_i_size > EXT4_I(inode)->i_disksize)
EXT4_I(inode)->i_disksize = new_i_size;
- ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
+ ret2 = generic_write_end(file, mapping, pos, len, copied,
page, fsdata);
copied = ret2;
if (ret2 < 0)
ret2 = ext4_journal_stop(handle);
if (!ret)
ret = ret2;
- unlock_page(page);
- page_cache_release(page);
return ret ? ret : copied;
}
struct page *page, void *fsdata)
{
handle_t *handle = ext4_journal_current_handle();
- struct inode *inode = file->f_mapping->host;
+ struct inode *inode = mapping->host;
int ret = 0, ret2;
loff_t new_i_size;
if (new_i_size > EXT4_I(inode)->i_disksize)
EXT4_I(inode)->i_disksize = new_i_size;
- ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
+ ret2 = generic_write_end(file, mapping, pos, len, copied,
page, fsdata);
copied = ret2;
if (ret2 < 0)
ret2 = ext4_journal_stop(handle);
if (!ret)
ret = ret2;
- unlock_page(page);
- page_cache_release(page);
return ret ? ret : copied;
}
ret = ret2;
}
+ unlock_page(page);
ret2 = ext4_journal_stop(handle);
if (!ret)
ret = ret2;
- unlock_page(page);
page_cache_release(page);
return ret ? ret : copied;
return 0;
}
+static int ext4_bh_unmapped_or_delay(handle_t *handle, struct buffer_head *bh)
+{
+ return !buffer_mapped(bh) || buffer_delay(bh);
+}
+
/*
- * Note that we always start a transaction even if we're not journalling
- * data. This is to preserve ordering: any hole instantiation within
- * __block_write_full_page -> ext4_get_block() should be journalled
- * along with the data so we don't crash and then get metadata which
- * refers to old data.
+ * 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
+ * we are journaling data, we cannot start transaction directly because
+ * transaction start ranks above page lock so we have to do some magic...
*
* In all journalling modes block_write_full_page() will start the I/O.
*
* disastrous. Any write() or metadata operation will sync the fs for
* us.
*
- * AKPM2: if all the page's buffers are mapped to disk and !data=journal,
- * we don't need to open a transaction here.
*/
-static int ext4_ordered_writepage(struct page *page,
+static int __ext4_ordered_writepage(struct page *page,
struct writeback_control *wbc)
{
struct inode *inode = page->mapping->host;
int ret = 0;
int err;
- J_ASSERT(PageLocked(page));
-
- /*
- * We give up here if we're reentered, because it might be for a
- * different filesystem.
- */
- if (ext4_journal_current_handle())
- goto out_fail;
-
- handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
-
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
- goto out_fail;
- }
-
if (!page_has_buffers(page)) {
create_empty_buffers(page, inode->i_sb->s_blocksize,
(1 << BH_Dirty)|(1 << BH_Uptodate));
* and generally junk.
*/
if (ret == 0) {
- err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
+ handle = ext4_journal_start(inode,
+ ext4_writepage_trans_blocks(inode));
+ if (IS_ERR(handle)) {
+ ret = PTR_ERR(handle);
+ goto out_put;
+ }
+
+ ret = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
NULL, jbd2_journal_dirty_data_fn);
+ err = ext4_journal_stop(handle);
if (!ret)
ret = err;
}
- walk_page_buffers(handle, page_bufs, 0,
- PAGE_CACHE_SIZE, NULL, bput_one);
- err = ext4_journal_stop(handle);
- if (!ret)
- ret = err;
+out_put:
+ walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, NULL,
+ bput_one);
return ret;
+}
+
+static int ext4_ordered_writepage(struct page *page,
+ struct writeback_control *wbc)
+{
+ struct inode *inode = page->mapping->host;
+ loff_t size = i_size_read(inode);
+ loff_t len;
+
+ J_ASSERT(PageLocked(page));
+ J_ASSERT(page_has_buffers(page));
+ if (page->index == size >> PAGE_CACHE_SHIFT)
+ len = size & ~PAGE_CACHE_MASK;
+ else
+ len = PAGE_CACHE_SIZE;
+ BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
+ ext4_bh_unmapped_or_delay));
+
+ /*
+ * We give up here if we're reentered, because it might be for a
+ * different filesystem.
+ */
+ if (!ext4_journal_current_handle())
+ return __ext4_ordered_writepage(page, wbc);
-out_fail:
redirty_page_for_writepage(wbc, page);
unlock_page(page);
- return ret;
+ return 0;
}
+static int __ext4_writeback_writepage(struct page *page,
+ struct writeback_control *wbc)
+{
+ struct inode *inode = page->mapping->host;
+
+ 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)
{
struct inode *inode = page->mapping->host;
+ loff_t size = i_size_read(inode);
+ loff_t len;
+
+ J_ASSERT(PageLocked(page));
+ J_ASSERT(page_has_buffers(page));
+ if (page->index == size >> PAGE_CACHE_SHIFT)
+ len = size & ~PAGE_CACHE_MASK;
+ else
+ len = PAGE_CACHE_SIZE;
+ BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
+ ext4_bh_unmapped_or_delay));
+
+ if (!ext4_journal_current_handle())
+ return __ext4_writeback_writepage(page, wbc);
+
+ redirty_page_for_writepage(wbc, page);
+ unlock_page(page);
+ return 0;
+}
+
+static int __ext4_journalled_writepage(struct page *page,
+ struct writeback_control *wbc)
+{
+ 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;
- if (ext4_journal_current_handle())
- goto out_fail;
+ 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
+ * references to buffers so we are safe */
+ unlock_page(page);
handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
if (IS_ERR(handle)) {
ret = PTR_ERR(handle);
- goto out_fail;
+ goto out;
}
- if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
- ret = nobh_writepage(page, ext4_get_block, wbc);
- else
- ret = block_write_full_page(page, ext4_get_block, wbc);
+ 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;
err = ext4_journal_stop(handle);
if (!ret)
ret = err;
- return ret;
-out_fail:
- redirty_page_for_writepage(wbc, page);
+ walk_page_buffers(handle, page_bufs, 0,
+ PAGE_CACHE_SIZE, NULL, bput_one);
+ EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
+ goto out;
+
+out_unlock:
unlock_page(page);
+out:
return ret;
}
struct writeback_control *wbc)
{
struct inode *inode = page->mapping->host;
- handle_t *handle = NULL;
- int ret = 0;
- int err;
+ loff_t size = i_size_read(inode);
+ loff_t len;
- if (ext4_journal_current_handle())
- goto no_write;
+ J_ASSERT(PageLocked(page));
+ J_ASSERT(page_has_buffers(page));
+ if (page->index == size >> PAGE_CACHE_SHIFT)
+ len = size & ~PAGE_CACHE_MASK;
+ else
+ len = PAGE_CACHE_SIZE;
+ BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
+ ext4_bh_unmapped_or_delay));
- handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
+ if (ext4_journal_current_handle())
goto no_write;
- }
- if (!page_has_buffers(page) || PageChecked(page)) {
+ if (PageChecked(page)) {
/*
* It's mmapped pagecache. Add buffers and journal it. There
* doesn't seem much point in redirtying the page here.
*/
ClearPageChecked(page);
- ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
- ext4_get_block);
- if (ret != 0) {
- ext4_journal_stop(handle);
- goto out_unlock;
- }
- ret = walk_page_buffers(handle, page_buffers(page), 0,
- PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
-
- err = walk_page_buffers(handle, page_buffers(page), 0,
- PAGE_CACHE_SIZE, NULL, write_end_fn);
- if (ret == 0)
- ret = err;
- EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
- unlock_page(page);
+ return __ext4_journalled_writepage(page, wbc);
} else {
/*
* It may be a page full of checkpoint-mode buffers. We don't
* really know unless we go poke around in the buffer_heads.
* But block_write_full_page will do the right thing.
*/
- ret = block_write_full_page(page, ext4_get_block, wbc);
+ return block_write_full_page(page, ext4_get_block, wbc);
}
- err = ext4_journal_stop(handle);
- if (!ret)
- ret = err;
-out:
- return ret;
-
no_write:
redirty_page_for_writepage(wbc, page);
-out_unlock:
unlock_page(page);
- goto out;
+ return 0;
}
static int ext4_readpage(struct file *file, struct page *page)
* This required during truncate. We need to physically zero the tail end
* of that block so it doesn't yield old data if the file is later grown.
*/
-int ext4_block_truncate_page(handle_t *handle, struct page *page,
+int ext4_block_truncate_page(handle_t *handle,
struct address_space *mapping, loff_t from)
{
ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
ext4_lblk_t iblock;
struct inode *inode = mapping->host;
struct buffer_head *bh;
+ struct page *page;
int err = 0;
+ page = grab_cache_page(mapping, from >> PAGE_CACHE_SHIFT);
+ if (!page)
+ return -EINVAL;
+
blocksize = inode->i_sb->s_blocksize;
length = blocksize - (offset & (blocksize - 1));
iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
int n;
ext4_lblk_t last_block;
unsigned blocksize = inode->i_sb->s_blocksize;
- struct page *page;
if (!ext4_can_truncate(inode))
return;
- /*
- * We have to lock the EOF page here, because lock_page() nests
- * outside jbd2_journal_start().
- */
- if ((inode->i_size & (blocksize - 1)) == 0) {
- /* Block boundary? Nothing to do */
- page = NULL;
- } else {
- page = grab_cache_page(mapping,
- inode->i_size >> PAGE_CACHE_SHIFT);
- if (!page)
- return;
- }
-
if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
- ext4_ext_truncate(inode, page);
+ ext4_ext_truncate(inode);
return;
}
handle = start_transaction(inode);
- if (IS_ERR(handle)) {
- if (page) {
- clear_highpage(page);
- flush_dcache_page(page);
- unlock_page(page);
- page_cache_release(page);
- }
+ if (IS_ERR(handle))
return; /* AKPM: return what? */
- }
last_block = (inode->i_size + blocksize-1)
>> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
- if (page)
- ext4_block_truncate_page(handle, page, mapping, inode->i_size);
+ if (inode->i_size & (blocksize - 1))
+ if (ext4_block_truncate_page(handle, mapping, inode->i_size))
+ goto out_stop;
n = ext4_block_to_path(inode, last_block, offsets, NULL);
if (n == 0)
projects / users / hch / dma-mapping.git / commitdiff