From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A1BB14446ED; Tue, 4 Aug 2026 15:44:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785858293; cv=none; b=V01J8WLvPS7zWtGeSDz4crZd9F6cnwDflREooq4oVIpQeEyzQNf7FgBNpev3SHAi1a2mUFRu9fcS+nU7uqynf0rDYQOmz+uRImeLULB0wFgmm1trb3cHY2t6AoZiB4vs6EyRNtoEJ1+hJrpc17bh4IHLmkZp6Gyp6WV3PqjeZBU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785858293; c=relaxed/simple; bh=SesH10CprPHiL4F/9NJfV1Bwr2tG3coz+xIULq2gPBA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Fv4CYmneSTS3o0cjis2VcUR49eI2K+Y7AN7Mt8B8iQCDDeD+Ec6k8VbCJrLMRbTU8AioTVF7HrRTqN5M4i60PU5pjRjBC9yZCjFFWfvqTnrh6F1sSgYGHPu7ujMqnVwlxgTCigSu/F7W+zHj60zkk+/WzEwEnEyclXyw6t9yqNo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Fe1nhBYM; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Fe1nhBYM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B09531F00A3E; Tue, 4 Aug 2026 15:44:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785858290; bh=Xrv4R7OK6OePmDuDYMrX2WVaMn0ORsRTONpLfBbBmUs=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=Fe1nhBYMEqA5LBa5/n4N8W9GuoclwIalM8PdmL1IblmnKQKnXHqD42VwgV9xj3Yvs P09JEtSqrXYZrgDmGCbI1V8vmsaHneC0GA6mWTKmBV3TLow8VlG1LaOLJ/Z4Qu2oyN ERNAb+fxgGS5kXX6Xo/JBY9XoQqEJGB4GgW1yX35tuyk6mC8WI0nTqluYqcaW1A1mx E0aqpPUlpriuL5PugTsaSNBnWsdAUxfUazjQSJnLdoWMszho+WN8ytORxxp2xcI5lA AD/KF+f/qDnehQM4Lrbl4tJu4gQ5Jn9jiqOVQwVQHGDT8ndjb7npArO947C7VvIgfn v86HechtTTSpQ== From: Jeff Layton Date: Tue, 04 Aug 2026 11:44:34 -0400 Subject: [PATCH v2 2/5] btrfs: split btrfs_insert_delayed_dir_index() into prealloc and commit phases 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="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260804-btrfs-enomem-v2-2-4d923170e8c1@kernel.org> References: <20260804-btrfs-enomem-v2-0-4d923170e8c1@kernel.org> In-Reply-To: <20260804-btrfs-enomem-v2-0-4d923170e8c1@kernel.org> To: Chris Mason , David Sterba Cc: Qu Wenruo , linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, Jeff Layton X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=8441; i=jlayton@kernel.org; h=from:subject:message-id; bh=SesH10CprPHiL4F/9NJfV1Bwr2tG3coz+xIULq2gPBA=; b=owEBbQKS/ZANAwAKAQAOaEEZVoIVAcsmYgBqcgjvA98ApuCVPY+vI5gP4js3uCo2AMP39insN mNR0/ESACSJAjMEAAEKAB0WIQRLwNeyRHGyoYTq9dMADmhBGVaCFQUCanII7wAKCRAADmhBGVaC Fcx5D/9jaYk1xeuMk4JBq+0LkunOypeeIisfkyHRi6b1Lf4QJStxqeeM+Es96REIsK295q61GqN oGqi1Tt43OPZAe4MLifUVaO5x31Htd/8ajlycNGejWc6d3tQ7C+bMdfJhVpoB9KD7Zb1ujIU6Jp KfrDG0CaFOegnmGWKq41CTC4vfFC8in2r9NFTCg4ChW5WMpK0IQPKh27vKbIDLSj6ed/vPlNsaa wgOaHXgvI7BoSbv9WZPYG0zmf86puFn3iRKnm87umvaCRW/VEj/Qqz8SQb2Sdhu+vsrKgE1Mjd6 nk28iFJp665+ADvw0BsVjQsKVNflE0CB521DwsbNL91PVRUpRrAFz2RfjPsNmo51MCnL2jqnxl0 iedsxvPy1ok9Sz1aTjvAc8HlK1osQe1gGUi7joWVn3ylkx7p9hHAg1zYlNETKDiKlb5OW888mXp wW2cl/IWGpO0ApIau7Dz/PcxoWOUidULQGt9PhqsMZWiWBy40tvTGOiQ+Va/Krpc1wN83zQbkoO ffn2x0Dt+BwMfpcy75jxI/Tt3y1tqFdnCDvy/KuU1y8V0Hq2AwN0Sb937Ux2r60JmaHck788i1W 1v+RiiQi5egXSEBq69dKPz8yWVtsnekkL5+AXWwSp4u/cHf17TGpksQTrioj62UUp5Uvl7MSYEC ds3OjAsYsI+qsCw== X-Developer-Key: i=jlayton@kernel.org; a=openpgp; fpr=4BC0D7B24471B2A184EAF5D3000E684119568215 Split btrfs_insert_delayed_dir_index() into three functions using a new btrfs_dir_index_prealloc struct to bundle the pre-allocated resources: - btrfs_prealloc_delayed_dir_index(): performs the two GFP_NOFS allocations (delayed node + delayed item) that can fail with -ENOMEM. - btrfs_insert_delayed_dir_index_prealloc(): populates the item data, inserts into the rb-tree, and reserves metadata space. Cannot fail with -ENOMEM since all allocations were done in the prealloc step. - btrfs_free_delayed_dir_index_prealloc(): frees pre-allocated resources when the caller's btree insertion fails. The original btrfs_insert_delayed_dir_index() is refactored into a thin wrapper that calls the prealloc and commit functions. This split allows callers to move the fallible memory allocations before the point of no return (the DIR_ITEM btree insertion), so that -ENOMEM can be returned cleanly without aborting the transaction. Assisted-by: LLM Signed-off-by: Jeff Layton --- fs/btrfs/delayed-inode.c | 111 +++++++++++++++++++++++++++++++++++++---------- fs/btrfs/delayed-inode.h | 17 ++++++++ 2 files changed, 104 insertions(+), 24 deletions(-) diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c index db2ffab0941a..95d2dca80444 100644 --- a/fs/btrfs/delayed-inode.c +++ b/fs/btrfs/delayed-inode.c @@ -6,6 +6,7 @@ #include #include +#include #include "ctree.h" #include "fs.h" #include "messages.h" @@ -1469,35 +1470,74 @@ static void btrfs_release_dir_index_item_space(struct btrfs_trans_handle *trans) trans->bytes_reserved -= bytes; } -/* Will return 0, -ENOMEM or -EEXIST (index number collision, unexpected). */ -int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans, - const char *name, int name_len, - struct btrfs_inode *dir, - const struct btrfs_disk_key *disk_key, u8 flags, - u64 index) +/* + * Pre-allocate a delayed node and delayed item for a dir index insertion. + * Call this before modifying the btree so that ENOMEM can be returned + * before any on-disk state has changed. + * + * Returns 0 on success, -ENOMEM on allocation failure. + */ +int btrfs_prealloc_delayed_dir_index(struct btrfs_inode *dir, + const char *name, int name_len, + struct btrfs_dir_index_prealloc *prealloc) +{ + struct btrfs_delayed_node *node; + struct btrfs_delayed_item *item; + + node = btrfs_get_or_create_delayed_node(dir, &prealloc->tracker); + if (IS_ERR(node)) + return PTR_ERR(node); + + item = btrfs_alloc_delayed_item(sizeof(struct btrfs_dir_item) + name_len, + node, BTRFS_DELAYED_INSERTION_ITEM); + if (!item) { + btrfs_release_delayed_node(node, &prealloc->tracker); + return -ENOMEM; + } + + prealloc->node = node; + prealloc->item = item; + return 0; +} +ALLOW_ERROR_INJECTION(btrfs_prealloc_delayed_dir_index, ERRNO); + +/* + * Free resources from btrfs_prealloc_delayed_dir_index() when the btree + * insertion failed and we will not commit the delayed dir index. + */ +void btrfs_free_delayed_dir_index_prealloc(struct btrfs_trans_handle *trans, + struct btrfs_dir_index_prealloc *prealloc) { + btrfs_release_delayed_item(prealloc->item); + btrfs_release_dir_index_item_space(trans); + btrfs_release_delayed_node(prealloc->node, &prealloc->tracker); +} + +/* + * Commit a pre-allocated delayed dir index item. The delayed node and item + * must have been returned by btrfs_prealloc_delayed_dir_index(). This + * populates the item, adds it to the delayed node's rb-tree, and reserves + * metadata space. It cannot fail with ENOMEM. + * + * Will return 0 or -EEXIST (index number collision, unexpected). + */ +int btrfs_insert_delayed_dir_index_prealloc(struct btrfs_trans_handle *trans, + struct btrfs_inode *dir, + struct btrfs_dir_index_prealloc *prealloc, + const struct btrfs_disk_key *disk_key, + u8 flags, u64 index) +{ + struct btrfs_delayed_node *delayed_node = prealloc->node; + struct btrfs_ref_tracker *tracker = &prealloc->tracker; + struct btrfs_delayed_item *delayed_item = prealloc->item; struct btrfs_fs_info *fs_info = trans->fs_info; const unsigned int leaf_data_size = BTRFS_LEAF_DATA_SIZE(fs_info); - struct btrfs_delayed_node *delayed_node; - struct btrfs_ref_tracker delayed_node_tracker; - struct btrfs_delayed_item *delayed_item; + const int name_len = delayed_item->data_len - sizeof(struct btrfs_dir_item); struct btrfs_dir_item *dir_item; bool reserve_leaf_space; u32 data_len; int ret; - delayed_node = btrfs_get_or_create_delayed_node(dir, &delayed_node_tracker); - if (IS_ERR(delayed_node)) - return PTR_ERR(delayed_node); - - delayed_item = btrfs_alloc_delayed_item(sizeof(*dir_item) + name_len, - delayed_node, - BTRFS_DELAYED_INSERTION_ITEM); - if (!delayed_item) { - ret = -ENOMEM; - goto release_node; - } - delayed_item->index = index; dir_item = (struct btrfs_dir_item *)delayed_item->data; @@ -1506,7 +1546,7 @@ int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans, btrfs_set_stack_dir_data_len(dir_item, 0); btrfs_set_stack_dir_name_len(dir_item, name_len); btrfs_set_stack_dir_flags(dir_item, flags); - memcpy((char *)(dir_item + 1), name, name_len); + /* Name was already copied into delayed_item->data by the caller. */ data_len = delayed_item->data_len + sizeof(struct btrfs_item); @@ -1524,7 +1564,9 @@ int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans, if (unlikely(ret)) { btrfs_err(trans->fs_info, "error adding delayed dir index item, name: %.*s, index: %llu, root: %llu, dir: %llu, dir->index_cnt: %llu, delayed_node->index_cnt: %llu, error: %pe", - name_len, name, index, btrfs_root_id(delayed_node->root), + name_len, + (const char *)(dir_item + 1), + index, btrfs_root_id(delayed_node->root), delayed_node->inode_id, dir->index_cnt, delayed_node->index_cnt, ERR_PTR(ret)); btrfs_release_delayed_item(delayed_item); @@ -1562,10 +1604,31 @@ int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans, mutex_unlock(&delayed_node->mutex); release_node: - btrfs_release_delayed_node(delayed_node, &delayed_node_tracker); + btrfs_release_delayed_node(delayed_node, tracker); return ret; } +/* Will return 0, -ENOMEM or -EEXIST (index number collision, unexpected). */ +int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans, + const char *name, int name_len, + struct btrfs_inode *dir, + const struct btrfs_disk_key *disk_key, u8 flags, + u64 index) +{ + struct btrfs_dir_index_prealloc prealloc; + int ret; + + ret = btrfs_prealloc_delayed_dir_index(dir, name, name_len, &prealloc); + if (ret) + return ret; + + memcpy(prealloc.item->data + sizeof(struct btrfs_dir_item), name, + name_len); + + return btrfs_insert_delayed_dir_index_prealloc(trans, dir, &prealloc, + disk_key, flags, index); +} + static bool btrfs_delete_delayed_insertion_item(struct btrfs_delayed_node *node, u64 index) { diff --git a/fs/btrfs/delayed-inode.h b/fs/btrfs/delayed-inode.h index fc752863f89b..e310a257c9a6 100644 --- a/fs/btrfs/delayed-inode.h +++ b/fs/btrfs/delayed-inode.h @@ -121,6 +121,23 @@ int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans, const struct btrfs_disk_key *disk_key, u8 flags, u64 index); +struct btrfs_dir_index_prealloc { + struct btrfs_delayed_node *node; + struct btrfs_ref_tracker tracker; + struct btrfs_delayed_item *item; +}; + +int btrfs_prealloc_delayed_dir_index(struct btrfs_inode *dir, + const char *name, int name_len, + struct btrfs_dir_index_prealloc *prealloc); +void btrfs_free_delayed_dir_index_prealloc(struct btrfs_trans_handle *trans, + struct btrfs_dir_index_prealloc *prealloc); +int btrfs_insert_delayed_dir_index_prealloc(struct btrfs_trans_handle *trans, + struct btrfs_inode *dir, + struct btrfs_dir_index_prealloc *prealloc, + const struct btrfs_disk_key *disk_key, + u8 flags, u64 index); + int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans, struct btrfs_inode *dir, u64 index); -- 2.55.0