From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 50DE642A7AF for ; Thu, 16 Jul 2026 14:56:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784213772; cv=none; b=S9g0GWtXPe9PEnvFMs/cC3n63ntVOfMROSEABMrWQR2RF5Jo864iY2v0S0y5CpwkkS4iNgGPxQJo3OdZv08c89cKUsyKBZJAc1SCGZrcrW87EMZen7u/0See2S/EaVK4YjUETEcb93NlSk60DQtgNONY3JusacnypkVkH6Lwbb8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784213772; c=relaxed/simple; bh=RnR7wJ6UBFjJYQ3neMTfo+BwEPdhTLE68eu7xMB8aIw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MEZBdCRBcOq0kqFahNAwzPWLaLuHPUaL9jl7gBg5uGx8/qS7sFdrhGjbFwl+VSSJAbv7Y3hkKC0oKPPPPZ3BGYdb38k+3tlv3V13B01ho8U3q8HBbBBGLKgfzGfOitoNy9cjcfBJ/67sZVCYRDVYlh5Va8ZAdoxR/ULewJzp3Gw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz; spf=pass smtp.mailfrom=suse.cz; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.cz Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 4369D789D0; Thu, 16 Jul 2026 14:55:57 +0000 (UTC) Authentication-Results: smtp-out1.suse.de; none Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 1EE7A779AD; Thu, 16 Jul 2026 14:55:57 +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 4kGKB/3wWGrkXQAAD6G6ig (envelope-from ); Thu, 16 Jul 2026 14:55:57 +0000 Received: by quack3.suse.cz (Postfix, from userid 1000) id 68EF0A0921; Thu, 16 Jul 2026 16:55:52 +0200 (CEST) From: Jan Kara To: Cc: Christian Brauner , aivazian.tigran@gmail.com, Ted Tso , , OGAWA Hirofumi , Jan Kara Subject: [PATCH v4 04/21] ext4: Allocate mapping_metadata_bhs struct on demand Date: Thu, 16 Jul 2026 16:55:26 +0200 Message-ID: <20260716145527.3580300-25-jack@suse.cz> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260716145359.28639-1-jack@suse.cz> References: <20260716145359.28639-1-jack@suse.cz> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=6911; i=jack@suse.cz; h=from:subject; bh=RnR7wJ6UBFjJYQ3neMTfo+BwEPdhTLE68eu7xMB8aIw=; b=owEBbQGS/pANAwAIAZydqgc/ZEDZAcsmYgBqWPDiIVgQt4sXaBj+SzvOeUTRLCmUTdMnIp9FD 5FWHdbYhcSJATMEAAEIAB0WIQSrWdEr1p4yirVVKBycnaoHP2RA2QUCaljw4gAKCRCcnaoHP2RA 2SdTB/4vzQSBhFZ1pI3K+4k4Slev1HpC76BDg24rTLgGRIi0A4Qrwb11RUpWEbJXHjrwqoNo2OV /4Dfa+F5/2ozgoQtBlwvJ/whaeFfSspIrNXM/xIgNtur5DTBB8xfwlAMQpt2Luj+cksTpzgW1vQ 251nmF8FNbO6obQRjBHTQtpcDIe+HYrmIwLQx77edvAFDdBTNG8at7Dpkve6hjmBfnkhaR2jEd7 4jBsCuItDiYM2nz+3L+fLxbYS/OORY913t6wGRqMoJgrGW3NekOsQFOFitk/dnQaAVluULPACYp kViwhik4jki8+zRestiZIX9TfXYjYtt23PeTEsi0NkJCIIfE X-Developer-Key: i=jack@suse.cz; a=openpgp; fpr=93C6099A142276A28BBE35D815BC833443038D8C Content-Transfer-Encoding: 8bit X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Rspamd-Queue-Id: 4369D789D0 X-Spam-Flag: NO X-Spam-Score: -4.00 X-Spam-Level: X-Rspamd-Action: no action X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated X-Spamd-Result: default: False [-4.00 / 50.00]; REPLY(-4.00)[]; TAGGED_RCPT(0.00)[] Currently every ext4 inode gets mapping_metadata_bhs struct although it is only needed when running without a journal and only for inodes where any metadata was dirtied. Allocate mapping_metadata_bhs struct on demand when dirtying the first metadata buffer for the inode. Acked-by: Theodore Ts'o Signed-off-by: Jan Kara --- fs/ext4/ext4.h | 13 ++++++++++++- fs/ext4/ext4_jbd2.c | 25 +++++++++++++++++++++---- fs/ext4/fsync.c | 12 ++++++++---- fs/ext4/inode.c | 12 ++++++++---- fs/ext4/super.c | 9 ++++++--- 5 files changed, 55 insertions(+), 16 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index b37c136ea3ab..64f8f63f4415 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1151,7 +1151,7 @@ struct ext4_inode_info { struct rw_semaphore i_data_sem; struct inode vfs_inode; struct jbd2_inode *jinode; - struct mapping_metadata_bhs i_metadata_bhs; + struct mapping_metadata_bhs *i_metadata_bhs; /* * File creation time. Its function is same as that of @@ -2126,6 +2126,17 @@ static inline bool ext4_inode_orphan_tracked(struct inode *inode) !list_empty(&EXT4_I(inode)->i_orphan); } +static inline struct mapping_metadata_bhs *ext4_i_metadata_bhs( + struct inode *inode) +{ + /* + * i_metadata_bhs is set in ext4_inode_attach_mmb() using cmpxchg(). + * We use READ_ONCE when accessing i_metadata_bhs to make sure we get + * consistent view for all accesses. + */ + return READ_ONCE(EXT4_I(inode)->i_metadata_bhs); +} + /* * Codes for operating systems */ diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c index 9a8c225f2753..3b2f8ac20bf8 100644 --- a/fs/ext4/ext4_jbd2.c +++ b/fs/ext4/ext4_jbd2.c @@ -350,6 +350,21 @@ int __ext4_journal_get_create_access(const char *where, unsigned int line, return 0; } +static void ext4_inode_attach_mmb(struct inode *inode) +{ + struct mapping_metadata_bhs *mmb; + + /* + * It's difficult to handle failure when marking buffer dirty without + * leaving filesystem corrupted + */ + mmb = kmalloc_obj(*mmb, GFP_NOFS | __GFP_NOFAIL); + mmb_init(mmb, &inode->i_data); + /* Someone swapped another mmb before us? */ + if (cmpxchg(&EXT4_I(inode)->i_metadata_bhs, NULL, mmb)) + kfree(mmb); +} + int __ext4_handle_dirty_metadata(const char *where, unsigned int line, handle_t *handle, struct inode *inode, struct buffer_head *bh) @@ -389,11 +404,13 @@ int __ext4_handle_dirty_metadata(const char *where, unsigned int line, err); } } else { - if (inode) - mmb_mark_buffer_dirty(bh, - &EXT4_I(inode)->i_metadata_bhs); - else + if (inode) { + if (!ext4_i_metadata_bhs(inode)) + ext4_inode_attach_mmb(inode); + mmb_mark_buffer_dirty(bh, ext4_i_metadata_bhs(inode)); + } else { mark_buffer_dirty(bh); + } if (inode && inode_needs_sync(inode)) { sync_dirty_buffer(bh); if (buffer_req(bh) && !buffer_uptodate(bh)) { diff --git a/fs/ext4/fsync.c b/fs/ext4/fsync.c index 924726dcc85f..b7ea4433f4be 100644 --- a/fs/ext4/fsync.c +++ b/fs/ext4/fsync.c @@ -46,6 +46,7 @@ static int ext4_sync_parent(struct inode *inode) { struct dentry *dentry, *next; + struct mapping_metadata_bhs *mmb; int ret = 0; if (!ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY)) @@ -68,9 +69,12 @@ static int ext4_sync_parent(struct inode *inode) * through ext4_evict_inode()) and so we are safe to flush * metadata blocks and the inode. */ - ret = mmb_sync(&EXT4_I(inode)->i_metadata_bhs); - if (ret) - break; + mmb = ext4_i_metadata_bhs(inode); + if (mmb) { + ret = mmb_sync(mmb); + if (ret) + break; + } ret = sync_inode_metadata(inode, 1); if (ret) break; @@ -89,7 +93,7 @@ static int ext4_fsync_nojournal(struct file *file, loff_t start, loff_t end, }; int ret; - ret = mmb_fsync_noflush(file, &EXT4_I(inode)->i_metadata_bhs, + ret = mmb_fsync_noflush(file, ext4_i_metadata_bhs(inode), start, end, datasync); if (ret) return ret; diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index ce99807c5f5b..e6acef486ee1 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -186,6 +186,8 @@ void ext4_evict_inode(struct inode *inode) if (EXT4_I(inode)->i_flags & EXT4_EA_INODE_FL) ext4_evict_ea_inode(inode); if (inode->i_nlink) { + struct mapping_metadata_bhs *mmb; + /* * If there's dirty page will lead to data loss, user * could see stale data. @@ -195,9 +197,9 @@ void ext4_evict_inode(struct inode *inode) ext4_warning_inode(inode, "data will be lost"); truncate_inode_pages_final(&inode->i_data); - /* Avoid mballoc special inode which has no proper iops */ - if (!EXT4_SB(inode->i_sb)->s_journal) - mmb_sync(&EXT4_I(inode)->i_metadata_bhs); + mmb = ext4_i_metadata_bhs(inode); + if (mmb) + mmb_sync(mmb); goto no_delete; } @@ -3452,6 +3454,7 @@ static bool ext4_release_folio(struct folio *folio, gfp_t wait) static bool ext4_inode_datasync_dirty(struct inode *inode) { journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; + struct mapping_metadata_bhs *mmb; if (journal) { if (jbd2_transaction_committed(journal, @@ -3462,8 +3465,9 @@ static bool ext4_inode_datasync_dirty(struct inode *inode) return true; } + mmb = ext4_i_metadata_bhs(inode); /* Any metadata buffers to write? */ - if (mmb_has_buffers(&EXT4_I(inode)->i_metadata_bhs)) + if (mmb && mmb_has_buffers(mmb)) return true; return inode_state_read_once(inode) & I_DIRTY_DATASYNC; } diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 245f67d10ded..8671fa1209dd 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1430,7 +1430,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb) INIT_WORK(&ei->i_rsv_conversion_work, ext4_end_io_rsv_work); ext4_fc_init_inode(&ei->vfs_inode); spin_lock_init(&ei->i_fc_lock); - mmb_init(&ei->i_metadata_bhs, &ei->vfs_inode.i_data); + ei->i_metadata_bhs = NULL; #ifdef CONFIG_LOCKDEP lockdep_set_subclass(&ei->i_data_sem, I_DATA_SEM_NORMAL); #endif @@ -1451,6 +1451,7 @@ static int ext4_drop_inode(struct inode *inode) static void ext4_free_in_core_inode(struct inode *inode) { fscrypt_free_inode(inode); + kfree(ext4_i_metadata_bhs(inode)); if (!list_empty(&(EXT4_I(inode)->i_fc_list))) { pr_warn("%s: inode %llu still in fc list", __func__, inode->i_ino); @@ -1529,9 +1530,11 @@ static void destroy_inodecache(void) void ext4_clear_inode(struct inode *inode) { + struct mapping_metadata_bhs *mmb = ext4_i_metadata_bhs(inode); + ext4_fc_del(inode); - if (!EXT4_SB(inode->i_sb)->s_journal) - mmb_invalidate(&EXT4_I(inode)->i_metadata_bhs); + if (mmb) + mmb_invalidate(mmb); clear_inode(inode); ext4_discard_preallocations(inode); /* -- 2.51.0