From patchwork Thu Sep 24 16:39:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goldwyn Rodrigues X-Patchwork-Id: 11797969 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 518F392C for ; Thu, 24 Sep 2020 16:40:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4271C2395C for ; Thu, 24 Sep 2020 16:40:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728617AbgIXQkI (ORCPT ); Thu, 24 Sep 2020 12:40:08 -0400 Received: from mx2.suse.de ([195.135.220.15]:36618 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726924AbgIXQkH (ORCPT ); Thu, 24 Sep 2020 12:40:07 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id DBE64B290; Thu, 24 Sep 2020 16:40:04 +0000 (UTC) From: Goldwyn Rodrigues To: linux-fsdevel@vger.kernel.org Cc: linux-btrfs@vger.kernel.org, david@fromorbit.com, hch@lst.de, johannes.thumshirn@wdc.com, dsterba@suse.com, darrick.wong@oracle.com, josef@toxicpanda.com, Goldwyn Rodrigues Subject: [PATCH 10/14] btrfs: Push inode locking and unlocking into buffered/direct write Date: Thu, 24 Sep 2020 11:39:17 -0500 Message-Id: <20200924163922.2547-11-rgoldwyn@suse.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200924163922.2547-1-rgoldwyn@suse.de> References: <20200924163922.2547-1-rgoldwyn@suse.de> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Goldwyn Rodrigues Push inode locking and unlocking closer to where we perform the I/O. For this we need to move the write checks inside the respective functions as well. pos is evaluated after generic_write_checks because O_APPEND can change iocb->ki_pos. Reviewed-by: Josef Bacik Signed-off-by: Goldwyn Rodrigues --- fs/btrfs/file.c | 70 +++++++++++++++++++++++++++++++------------------ 1 file changed, 45 insertions(+), 25 deletions(-) diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index a9d0950fd922..72fa1c692a53 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1699,7 +1699,7 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) { struct file *file = iocb->ki_filp; - loff_t pos = iocb->ki_pos; + loff_t pos; struct inode *inode = file_inode(file); struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); struct page **pages = NULL; @@ -1713,14 +1713,29 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, bool only_release_metadata = false; bool force_page_uptodate = false; loff_t old_isize = i_size_read(inode); + int ilock_flags = 0; + + if (iocb->ki_flags & IOCB_NOWAIT) + ilock_flags |= BTRFS_ILOCK_TRY; + + ret = btrfs_inode_lock(inode, ilock_flags); + if (ret < 0) + return ret; + + ret = btrfs_write_check(iocb, i); + if (ret <= 0) + goto out; + pos = iocb->ki_pos; nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE), PAGE_SIZE / (sizeof(struct page *))); nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied); nrptrs = max(nrptrs, 8); pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL); - if (!pages) - return -ENOMEM; + if (!pages) { + ret = -ENOMEM; + goto out; + } while (iov_iter_count(i) > 0) { struct extent_state *cached_state = NULL; @@ -1937,6 +1952,8 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb, pagecache_isize_extended(inode, old_isize, iocb->ki_pos); iocb->ki_pos += num_written; } +out: + btrfs_inode_unlock(inode, ilock_flags); return num_written ? num_written : ret; } @@ -1959,15 +1976,33 @@ static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) struct file *file = iocb->ki_filp; struct inode *inode = file_inode(file); struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); - loff_t pos = iocb->ki_pos; + loff_t pos; ssize_t written = 0; bool relock = false; ssize_t written_buffered; loff_t endbyte; int err; + int ilock_flags = 0; + + if (iocb->ki_flags & IOCB_NOWAIT) + ilock_flags |= BTRFS_ILOCK_TRY; + + err = btrfs_inode_lock(inode, ilock_flags); + if (err < 0) + return err; + + err = btrfs_write_check(iocb, from); + if (err <= 0) { + btrfs_inode_unlock(inode, ilock_flags); + goto out; + } + + pos = iocb->ki_pos; - if (check_direct_IO(fs_info, from, pos)) + if (check_direct_IO(fs_info, from, pos)) { + btrfs_inode_unlock(inode, ilock_flags); goto buffered; + } /* * If the write DIO is beyond the EOF, we need update @@ -1998,8 +2033,10 @@ static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from) if (relock) btrfs_inode_lock(inode, 0); - if (written < 0 || !iov_iter_count(from)) - return written; + if (written < 0 || !iov_iter_count(from)) { + err = written; + goto out; + } buffered: pos = iocb->ki_pos; @@ -2036,8 +2073,6 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, struct btrfs_root *root = BTRFS_I(inode)->root; ssize_t num_written = 0; const bool sync = iocb->ki_flags & IOCB_DSYNC; - ssize_t err; - int ilock_flags = 0; /* * If BTRFS flips readonly due to some impossible error, @@ -2051,19 +2086,6 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, (iocb->ki_flags & IOCB_NOWAIT)) return -EOPNOTSUPP; - if (iocb->ki_flags & IOCB_NOWAIT) - ilock_flags |= BTRFS_ILOCK_TRY; - - err = btrfs_inode_lock(inode, ilock_flags); - if (err < 0) - return err; - - err = btrfs_write_check(iocb, from); - if (err <= 0) { - btrfs_inode_unlock(inode, ilock_flags); - return err; - } - if (sync) atomic_inc(&BTRFS_I(inode)->sync_writers); @@ -2106,8 +2128,6 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, num_written = btrfs_buffered_write(iocb, from); } - btrfs_inode_unlock(inode, ilock_flags); - /* * We also have to set last_sub_trans to the current log transid, * otherwise subsequent syncs to a file that's been synced in this @@ -2123,7 +2143,7 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb, atomic_dec(&BTRFS_I(inode)->sync_writers); current->backing_dev_info = NULL; - return num_written ? num_written : err; + return num_written; } int btrfs_release_file(struct inode *inode, struct file *filp)