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[PATCH] revert "retries in ext4_prepare_write() violate ordering requirements"
Revert b46be05004
. Same reasoning as for ext3.
Cc: Kirill Korotaev <dev@openvz.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Ken Chen <kenneth.w.chen@intel.com>
Cc: Andrey Savochkin <saw@sw.ru>
Cc: <linux-ext4@vger.kernel.org>
Cc: Dmitriy Monakhov <dmonakhov@openvz.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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parent
1aa9b4b9bc
commit
7479d2b90b
@ -1147,102 +1147,37 @@ static int do_journal_get_write_access(handle_t *handle,
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return ext4_journal_get_write_access(handle, bh);
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}
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/*
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* The idea of this helper function is following:
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* if prepare_write has allocated some blocks, but not all of them, the
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* transaction must include the content of the newly allocated blocks.
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* This content is expected to be set to zeroes by block_prepare_write().
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* 2006/10/14 SAW
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*/
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static int ext4_prepare_failure(struct file *file, struct page *page,
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unsigned from, unsigned to)
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{
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struct address_space *mapping;
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struct buffer_head *bh, *head, *next;
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unsigned block_start, block_end;
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unsigned blocksize;
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int ret;
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handle_t *handle = ext4_journal_current_handle();
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mapping = page->mapping;
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if (ext4_should_writeback_data(mapping->host)) {
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/* optimization: no constraints about data */
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skip:
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return ext4_journal_stop(handle);
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}
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head = page_buffers(page);
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blocksize = head->b_size;
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for ( bh = head, block_start = 0;
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bh != head || !block_start;
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block_start = block_end, bh = next)
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{
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next = bh->b_this_page;
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block_end = block_start + blocksize;
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if (block_end <= from)
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continue;
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if (block_start >= to) {
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block_start = to;
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break;
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}
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if (!buffer_mapped(bh))
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/* prepare_write failed on this bh */
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break;
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if (ext4_should_journal_data(mapping->host)) {
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ret = do_journal_get_write_access(handle, bh);
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if (ret) {
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ext4_journal_stop(handle);
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return ret;
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}
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}
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/*
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* block_start here becomes the first block where the current iteration
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* of prepare_write failed.
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*/
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}
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if (block_start <= from)
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goto skip;
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/* commit allocated and zeroed buffers */
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return mapping->a_ops->commit_write(file, page, from, block_start);
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}
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static int ext4_prepare_write(struct file *file, struct page *page,
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unsigned from, unsigned to)
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{
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struct inode *inode = page->mapping->host;
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int ret, ret2;
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int needed_blocks = ext4_writepage_trans_blocks(inode);
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int ret, needed_blocks = ext4_writepage_trans_blocks(inode);
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handle_t *handle;
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int retries = 0;
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retry:
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handle = ext4_journal_start(inode, needed_blocks);
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if (IS_ERR(handle))
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return PTR_ERR(handle);
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if (IS_ERR(handle)) {
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ret = PTR_ERR(handle);
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goto out;
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}
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if (test_opt(inode->i_sb, NOBH) && ext4_should_writeback_data(inode))
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ret = nobh_prepare_write(page, from, to, ext4_get_block);
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else
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ret = block_prepare_write(page, from, to, ext4_get_block);
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if (ret)
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goto failure;
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goto prepare_write_failed;
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if (ext4_should_journal_data(inode)) {
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ret = walk_page_buffers(handle, page_buffers(page),
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from, to, NULL, do_journal_get_write_access);
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if (ret)
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/* fatal error, just put the handle and return */
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ext4_journal_stop(handle);
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}
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return ret;
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failure:
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ret2 = ext4_prepare_failure(file, page, from, to);
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if (ret2 < 0)
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return ret2;
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prepare_write_failed:
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if (ret)
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ext4_journal_stop(handle);
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if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
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goto retry;
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/* retry number exceeded, or other error like -EDQUOT */
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out:
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return ret;
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}
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