From f8514083cd61daef12fba5ef883ad9352c450428 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Fri, 5 Jun 2009 00:56:49 -0400 Subject: [PATCH] ext4: truncate the file properly if we fail to copy data from userspace In generic_perform_write if we fail to copy the user data we don't update the inode->i_size. We should truncate the file in the above case so that we don't have blocks allocated outside inode->i_size. Add the inode to orphan list in the same transaction as block allocation This ensures that if we crash in between the recovery would do the truncate. Signed-off-by: Aneesh Kumar K.V CC: Jan Kara Signed-off-by: "Theodore Ts'o" --- fs/ext4/inode.c | 128 ++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 102 insertions(+), 26 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 8d215881172f..2c10d346f7a3 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1549,6 +1549,52 @@ static int write_end_fn(handle_t *handle, struct buffer_head *bh) return ext4_handle_dirty_metadata(handle, NULL, bh); } +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) +{ + int i_size_changed = 0; + struct inode *inode = mapping->host; + handle_t *handle = ext4_journal_current_handle(); + + copied = block_write_end(file, mapping, pos, len, copied, page, fsdata); + + /* + * No need to use i_size_read() here, the i_size + * cannot change under us because we hold i_mutex. + * + * But it's important to update i_size while still holding page lock: + * page writeout could otherwise come in and zero beyond i_size. + */ + if (pos + copied > inode->i_size) { + i_size_write(inode, pos + copied); + i_size_changed = 1; + } + + if (pos + copied > EXT4_I(inode)->i_disksize) { + /* We need to mark inode dirty even if + * new_i_size is less that inode->i_size + * bu greater than i_disksize.(hint delalloc) + */ + ext4_update_i_disksize(inode, (pos + copied)); + i_size_changed = 1; + } + unlock_page(page); + page_cache_release(page); + + /* + * Don't mark the inode dirty under page lock. First, it unnecessarily + * makes the holding time of page lock longer. Second, it forces lock + * ordering of page lock and transaction start for journaling + * filesystems. + */ + if (i_size_changed) + ext4_mark_inode_dirty(handle, 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(). @@ -1572,21 +1618,15 @@ static int ext4_ordered_write_end(struct file *file, ret = ext4_jbd2_file_inode(handle, inode); if (ret == 0) { - loff_t new_i_size; - - new_i_size = pos + copied; - if (new_i_size > EXT4_I(inode)->i_disksize) { - ext4_update_i_disksize(inode, new_i_size); - /* We need to mark inode dirty even if - * new_i_size is less that inode->i_size - * bu greater than i_disksize.(hint delalloc) - */ - ext4_mark_inode_dirty(handle, inode); - } - - ret2 = generic_write_end(file, mapping, pos, len, copied, + ret2 = ext4_generic_write_end(file, mapping, pos, len, copied, page, fsdata); copied = ret2; + if (pos + len > inode->i_size) + /* if we have allocated more blocks and copied + * less. We will have blocks allocated outside + * inode->i_size. So truncate them + */ + ext4_orphan_add(handle, inode); if (ret2 < 0) ret = ret2; } @@ -1594,6 +1634,18 @@ static int ext4_ordered_write_end(struct file *file, if (!ret) ret = ret2; + if (pos + len > inode->i_size) { + vmtruncate(inode, inode->i_size); + /* + * If vmtruncate failed early the inode might still be + * on the orphan list; we need to make sure the inode + * is removed from the orphan list in that case. + */ + if (inode->i_nlink) + ext4_orphan_del(NULL, inode); + } + + return ret ? ret : copied; } @@ -1605,25 +1657,21 @@ static int ext4_writeback_write_end(struct file *file, handle_t *handle = ext4_journal_current_handle(); struct inode *inode = mapping->host; int ret = 0, ret2; - loff_t new_i_size; trace_mark(ext4_writeback_write_end, "dev %s ino %lu pos %llu len %u copied %u", inode->i_sb->s_id, inode->i_ino, (unsigned long long) pos, len, copied); - new_i_size = pos + copied; - if (new_i_size > EXT4_I(inode)->i_disksize) { - ext4_update_i_disksize(inode, new_i_size); - /* We need to mark inode dirty even if - * new_i_size is less that inode->i_size - * bu greater than i_disksize.(hint delalloc) - */ - ext4_mark_inode_dirty(handle, inode); - } - - ret2 = generic_write_end(file, mapping, pos, len, copied, + ret2 = ext4_generic_write_end(file, mapping, pos, len, copied, page, fsdata); copied = ret2; + if (pos + len > inode->i_size) + /* if we have allocated more blocks and copied + * less. We will have blocks allocated outside + * inode->i_size. So truncate them + */ + ext4_orphan_add(handle, inode); + if (ret2 < 0) ret = ret2; @@ -1631,6 +1679,17 @@ static int ext4_writeback_write_end(struct file *file, if (!ret) ret = ret2; + if (pos + len > inode->i_size) { + vmtruncate(inode, inode->i_size); + /* + * If vmtruncate failed early the inode might still be + * on the orphan list; we need to make sure the inode + * is removed from the orphan list in that case. + */ + if (inode->i_nlink) + ext4_orphan_del(NULL, inode); + } + return ret ? ret : copied; } @@ -1675,10 +1734,27 @@ static int ext4_journalled_write_end(struct file *file, } unlock_page(page); + page_cache_release(page); + if (pos + len > inode->i_size) + /* if we have allocated more blocks and copied + * less. We will have blocks allocated outside + * inode->i_size. So truncate them + */ + ext4_orphan_add(handle, inode); + ret2 = ext4_journal_stop(handle); if (!ret) ret = ret2; - page_cache_release(page); + if (pos + len > inode->i_size) { + vmtruncate(inode, inode->i_size); + /* + * If vmtruncate failed early the inode might still be + * on the orphan list; we need to make sure the inode + * is removed from the orphan list in that case. + */ + if (inode->i_nlink) + ext4_orphan_del(NULL, inode); + } return ret ? ret : copied; } -- 2.34.1