diff options
| -rw-r--r-- | fs/ext3/inode.c | 85 |
1 files changed, 75 insertions, 10 deletions
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c index 03ba5bcab186..beaf25f5112f 100644 --- a/fs/ext3/inode.c +++ b/fs/ext3/inode.c @@ -1148,37 +1148,102 @@ static int do_journal_get_write_access(handle_t *handle, return ext3_journal_get_write_access(handle, bh); } +/* + * The idea of this helper function is following: + * if prepare_write has allocated some blocks, but not all of them, the + * transaction must include the content of the newly allocated blocks. + * This content is expected to be set to zeroes by block_prepare_write(). + * 2006/10/14 SAW + */ +static int ext3_prepare_failure(struct file *file, struct page *page, + unsigned from, unsigned to) +{ + struct address_space *mapping; + struct buffer_head *bh, *head, *next; + unsigned block_start, block_end; + unsigned blocksize; + int ret; + handle_t *handle = ext3_journal_current_handle(); + + mapping = page->mapping; + if (ext3_should_writeback_data(mapping->host)) { + /* optimization: no constraints about data */ +skip: + return ext3_journal_stop(handle); + } + + head = page_buffers(page); + blocksize = head->b_size; + for ( bh = head, block_start = 0; + bh != head || !block_start; + block_start = block_end, bh = next) + { + next = bh->b_this_page; + block_end = block_start + blocksize; + if (block_end <= from) + continue; + if (block_start >= to) { + block_start = to; + break; + } + if (!buffer_mapped(bh)) + /* prepare_write failed on this bh */ + break; + if (ext3_should_journal_data(mapping->host)) { + ret = do_journal_get_write_access(handle, bh); + if (ret) { + ext3_journal_stop(handle); + return ret; + } + } + /* + * block_start here becomes the first block where the current iteration + * of prepare_write failed. + */ + } + if (block_start <= from) + goto skip; + + /* commit allocated and zeroed buffers */ + return mapping->a_ops->commit_write(file, page, from, block_start); +} + static int ext3_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to) { struct inode *inode = page->mapping->host; - int ret, needed_blocks = ext3_writepage_trans_blocks(inode); + int ret, ret2; + int needed_blocks = ext3_writepage_trans_blocks(inode); handle_t *handle; int retries = 0; retry: handle = ext3_journal_start(inode, needed_blocks); - if (IS_ERR(handle)) { - ret = PTR_ERR(handle); - goto out; - } + if (IS_ERR(handle)) + return PTR_ERR(handle); if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode)) ret = nobh_prepare_write(page, from, to, ext3_get_block); else ret = block_prepare_write(page, from, to, ext3_get_block); if (ret) - goto prepare_write_failed; + goto failure; if (ext3_should_journal_data(inode)) { ret = walk_page_buffers(handle, page_buffers(page), from, to, NULL, do_journal_get_write_access); + if (ret) + /* fatal error, just put the handle and return */ + journal_stop(handle); } -prepare_write_failed: - if (ret) - ext3_journal_stop(handle); + return ret; + +failure: + ret2 = ext3_prepare_failure(file, page, from, to); + if (ret2 < 0) + return ret2; if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries)) goto retry; -out: + /* retry number exceeded, or other error like -EDQUOT */ return ret; } |
