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Fri, 19 Apr 2024 17:30:45 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id gVyRIUWqImZ5JwAAD6G6ig (envelope-from ); Fri, 19 Apr 2024 17:30:45 +0000 Date: Fri, 19 Apr 2024 19:23:10 +0200 From: David Sterba To: Anand Jain Cc: linux-btrfs@vger.kernel.org Subject: Re: [PATCH v2 10/11] btrfs: btrfs_drop_snapshot optimize return variable Message-ID: <20240419172310.GA3492@twin.jikos.cz> Reply-To: dsterba@suse.cz References: Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) X-Spam-Flag: NO X-Spam-Score: -4.00 X-Spam-Level: X-Spamd-Result: default: False [-4.00 / 50.00]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; HAS_REPLYTO(0.30)[dsterba@suse.cz]; NEURAL_HAM_SHORT(-0.20)[-0.999]; MIME_GOOD(-0.10)[text/plain]; MIME_TRACE(0.00)[0:+]; RCPT_COUNT_TWO(0.00)[2]; TO_DN_SOME(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; RCVD_TLS_ALL(0.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; DKIM_SIGNED(0.00)[suse.cz:s=susede2_rsa,suse.cz:s=susede2_ed25519]; REPLYTO_ADDR_EQ_FROM(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.cz:replyto,imap1.dmz-prg2.suse.org:helo,imap1.dmz-prg2.suse.org:rdns] On Thu, Apr 18, 2024 at 03:08:42PM +0800, Anand Jain wrote: > Drop the variable 'err', reuse the variable 'ret' by reinitializing it to > zero where necessary. > > Signed-off-by: Anand Jain > --- > v2: handle return error better, no need of original 'ret'. (Josef). > > fs/btrfs/extent-tree.c | 48 +++++++++++++++++++++--------------------- > 1 file changed, 24 insertions(+), 24 deletions(-) > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index 78dc94a97e35..17aa45b906bb 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -5833,8 +5833,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc) > struct btrfs_root_item *root_item = &root->root_item; > struct walk_control *wc; > struct btrfs_key key; > - int err = 0; > - int ret; > + int ret = 0; > int level; > bool root_dropped = false; > bool unfinished_drop = false; > @@ -5843,14 +5842,14 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc) > > path = btrfs_alloc_path(); > if (!path) { > - err = -ENOMEM; > + ret = -ENOMEM; > goto out; > } > > wc = kzalloc(sizeof(*wc), GFP_NOFS); > if (!wc) { > btrfs_free_path(path); > - err = -ENOMEM; > + ret = -ENOMEM; > goto out; > } > > @@ -5863,12 +5862,12 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc) > else > trans = btrfs_start_transaction(tree_root, 0); > if (IS_ERR(trans)) { > - err = PTR_ERR(trans); > + ret = PTR_ERR(trans); > goto out_free; > } > > - err = btrfs_run_delayed_items(trans); > - if (err) > + ret = btrfs_run_delayed_items(trans); > + if (ret) > goto out_end_trans; > > /* > @@ -5899,11 +5898,11 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc) > path->lowest_level = level; > ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); > path->lowest_level = 0; > - if (ret < 0) { > - err = ret; > + if (ret < 0) > goto out_end_trans; > - } > + > WARN_ON(ret > 0); > + ret = 0; > > /* > * unlock our path, this is safe because only this > @@ -5916,14 +5915,17 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc) > btrfs_tree_lock(path->nodes[level]); > path->locks[level] = BTRFS_WRITE_LOCK; > > + /* > + * btrfs_lookup_extent_info() returns 0 for success, > + * or < 0 for error. > + */ > ret = btrfs_lookup_extent_info(trans, fs_info, > path->nodes[level]->start, > level, 1, &wc->refs[level], > &wc->flags[level], NULL); > - if (ret < 0) { > - err = ret; > + if (ret < 0) > goto out_end_trans; > - } > + > BUG_ON(wc->refs[level] == 0); > > if (level == btrfs_root_drop_level(root_item)) > @@ -5949,19 +5951,18 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc) > ret = walk_down_tree(trans, root, path, wc); > if (ret < 0) { > btrfs_abort_transaction(trans, ret); > - err = ret; > break; > } > > ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL); > if (ret < 0) { > btrfs_abort_transaction(trans, ret); > - err = ret; > break; > } > > if (ret > 0) { > BUG_ON(wc->stage != DROP_REFERENCE); > + ret = 0; > break; > } > > @@ -5983,7 +5984,6 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc) > root_item); > if (ret) { > btrfs_abort_transaction(trans, ret); > - err = ret; > goto out_end_trans; > } > > @@ -5994,7 +5994,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc) > if (!for_reloc && btrfs_need_cleaner_sleep(fs_info)) { > btrfs_debug(fs_info, > "drop snapshot early exit"); > - err = -EAGAIN; > + ret = -EAGAIN; > goto out_free; > } > > @@ -6008,19 +6008,18 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc) > else > trans = btrfs_start_transaction(tree_root, 0); > if (IS_ERR(trans)) { > - err = PTR_ERR(trans); > + ret = PTR_ERR(trans); > goto out_free; > } > } > } > btrfs_release_path(path); > - if (err) > + if (ret) > goto out_end_trans; > > ret = btrfs_del_root(trans, &root->root_key); > if (ret) { > btrfs_abort_transaction(trans, ret); > - err = ret; > goto out_end_trans; > } > > @@ -6029,10 +6028,11 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc) > NULL, NULL); > if (ret < 0) { > btrfs_abort_transaction(trans, ret); > - err = ret; > goto out_end_trans; > } else if (ret > 0) { > - /* if we fail to delete the orphan item this time > + ret = 0; > + /* > + * if we fail to delete the orphan item this time If you change comments please also fix the formatting or spelling, in this case first letter is uppercase. > * around, it'll get picked up the next time. > * > * The most common failure here is just -ENOENT. > @@ -6067,7 +6067,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc) > * We were an unfinished drop root, check to see if there are any > * pending, and if not clear and wake up any waiters. > */ > - if (!err && unfinished_drop) > + if (!ret && unfinished_drop) > btrfs_maybe_wake_unfinished_drop(fs_info); > > /* > @@ -6079,7 +6079,7 @@ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref, int for_reloc) > */ > if (!for_reloc && !root_dropped) > btrfs_add_dead_root(root); > - return err; > + return ret; > } > > /* > -- > 2.41.0 >