From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f176.google.com (mail-pg1-f176.google.com [209.85.215.176]) (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 3B71944BC9F for ; Tue, 28 Apr 2026 16:08:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.176 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777392506; cv=none; b=OsBjdCG1yxfYtMoKrw1ROQjry50RwBFG5wiLFT4xHXq7ZOb/ZS7uqoQPEey4DgYiwYeHeXdQiA7IOnroO7Eve+aS9Su+TnWLtAirEegFRPePzf57VScvtoIooR/MPgeXQ/NLMHkg1qdUbjqjA1pk9JXa1TLvPXG8HBraG1uKRno= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777392506; c=relaxed/simple; bh=6dnBavsoUPGKOpuSr3/LGHdvQnNq/ldgLGdG45nUMLY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BnzW+MTC5L/qO+zr2sVoC/2RaJc4ZoCTkmmKPzIKhj2YP7JjAdT2uAcgAgIEW66GpSk91bIIaZC6kaafjHpCkFf7+hW+iYJyYeo4sheI7AskUtGjUcJEogU0dBf+5cT54VmAlNaWAANLllK7lZosrdQnRJpCRO1BGtdww6VXovw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=CddK1cPc; arc=none smtp.client-ip=209.85.215.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="CddK1cPc" Received: by mail-pg1-f176.google.com with SMTP id 41be03b00d2f7-c648bc907ebso7595817a12.3 for ; Tue, 28 Apr 2026 09:08:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1777392504; x=1777997304; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=GjSkteazy2KtXict54lW3Ei5YfQmOP5DNfNIY6d4raw=; b=CddK1cPcPBfm8VLvNKewOQ96UgbknP7D5Ap2LQPgPqNyLmFaNlKOEVHvo8Uib5Sju4 C4wsey4IIGcnCY8yMO80sDBG54rOHolBgyir+n5jIeBCrT9yStww3mqKnLcespcks56e anV8yZzJUeAXK9yVL4yGY+JqefKPcq6J1i9FNcNmxMLXIcB79tLZ80LuCJ2RofyuY4Qw HkcwcXFN3lJyaYUCunNOFcoAH1agv9HnCyalUW8pdiJUwuwe0UjlYq96kL8YfqurNoEa eNni+4z/L4biLJZA0sPg+cboL0oFmejgw6pPurgiv4Oz94/2nvY155M8fRI/OP0BK0p6 objw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777392504; x=1777997304; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=GjSkteazy2KtXict54lW3Ei5YfQmOP5DNfNIY6d4raw=; b=LFPAWob91YyZLfYf5+ethx8jmlR1VT1BS2YRt+aER9dXj/5UXXWuBP4tUWLzOQ2kGs PE1MEDSAmM3f2xEkHVocNlhFa2Go6OciW6Fdh/DiudSxRiUoSIS4GTGvCxPiiAYHRhFr QpoEppSPVxEBIn2eQUG2dx7uPxkR6zb4s9TXWcf5uJYJnWzXLdYGt9WNDLv1027ntdWk aJTHmAgbPleGcgULAzsGF15C+hQ/u9d3ei4DSZH0d7yaBMMSTDjoJ741qRXlEbbI1JOT y0a7UheqZOBtjPCrrrRlmOeuw0iFFAmGyJ7iU9tNlAdidd0fatVPjCxvXzhW43quybgI Tthw== X-Gm-Message-State: AOJu0YzN34wqkvozTWh2/OmR6RmlQiU/jQxzIB+qxD/tRPHdHTZklN1A 13tsSW3oA6fcBYkqu6nvLhhcUcTnVHgsjH/xXcc2iaAJxhbT1ZUy9ZQ+eEiJJYPQ X-Gm-Gg: AeBDietibQ941B2Ex36UwzL0AQp42ab28zfh9R2D2NHEn55qFYBLqyavpJIHqQqPT4w U8MC/rzxUwKphuOy5ZbQyxnI4f8tuv6BKDypFCZw/yCiPMlDFwQ1MbSRrFM95AMdpSLyoJTXJO4 rQWPkQhRiaOebt0dOELUVE/Sm3oRha7Wj5F7fLDmL7c9yyfL8ojkdf3QiwoGNlfzteCQDWlxvFD YAJFGwUoIFHid3on8jDc57YTPgufT5TCUoZzEaPBb+A0nfHwMgfSdb5HlI3jX5iSFOp2hf6jyKh ING4Ms18BgnpkhWKsdebPiQmzh0mYEIUdbJ/mF2ZQVYVscenBKmP+mhK5Y5x2xHZCi2hPV7airx eC7QrDlyFLicXhQ2OLffhWJyAzTH0+Ht5iRiNGgMI8dKJCf6z9DJLwhKuzzfSETlVX9kTzwD9Lw cWC+sboyjyn8FJvs9NAVFezzlPQuE/SeRMaXUKyMCNLhrxC1PCRdsPhq++VMCb36V/lxDSHGAIg nM= X-Received: by 2002:a17:903:1205:b0:2b2:4eec:9806 with SMTP id d9443c01a7336-2b97c406d7fmr37341115ad.8.1777392503799; Tue, 28 Apr 2026 09:08:23 -0700 (PDT) Received: from sprasad-dev1.corp.microsoft.com ([167.220.110.216]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2b97ac7894csm30864465ad.50.2026.04.28.09.08.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Apr 2026 09:08:23 -0700 (PDT) From: nspmangalore@gmail.com X-Google-Original-From: sprasad@microsoft.com To: linux-cifs@vger.kernel.org, smfrench@gmail.com, pc@manguebit.org, bharathsm@microsoft.com, dhowells@redhat.com, henrique.carvalho@suse.com, ematsumiya@suse.de Cc: Shyam Prasad N Subject: [PATCH v3 05/19] cifs: optimize readdir for small directories Date: Tue, 28 Apr 2026 21:37:50 +0530 Message-ID: <20260428160804.281745-5-sprasad@microsoft.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260428160804.281745-1-sprasad@microsoft.com> References: <20260428160804.281745-1-sprasad@microsoft.com> Precedence: bulk X-Mailing-List: linux-cifs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Shyam Prasad N For small directories (where the entire directory contents could be read in a single QueryDir request), we currently do an extra round-trip just to get a STATUS_NO_MORE_FILES back from the server. This change avoids doing that by adding another QueryDir to the first compound to the server for readdir. i.e. first request to readdir will correspond to a compound of (OPEN+QD1+QD2). QD2 will request for a smaller size (in anticipation of STATUS_NO_MORE_FILES). Signed-off-by: Shyam Prasad N --- fs/smb/client/smb2ops.c | 156 ++++++++++++++++++++++++++++++++++---- fs/smb/client/smb2pdu.c | 19 +++-- fs/smb/client/smb2pdu.h | 11 +++ fs/smb/client/smb2proto.h | 3 +- 4 files changed, 168 insertions(+), 21 deletions(-) diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index a9d68e5fcea91..f075330f88598 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -2450,18 +2450,21 @@ smb2_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon, struct cifs_search_info *srch_inf) { __le16 *utf16_path; - struct smb_rqst rqst[2]; - struct kvec rsp_iov[2]; - int resp_buftype[2]; + struct smb_rqst rqst[3]; + struct kvec rsp_iov[3]; + int resp_buftype[3]; struct kvec open_iov[SMB2_CREATE_IOV_SIZE]; - struct kvec qd_iov[SMB2_QUERY_DIRECTORY_IOV_SIZE]; + struct kvec qd_iov[SMB2_QUERY_DIRECTORY_IOV_SIZE + 1]; /* +1 for padding */ + struct kvec qd2_iov[SMB2_QUERY_DIRECTORY_IOV_SIZE + 1]; /* +1 for padding */ int rc, flags = 0; u8 oplock = SMB2_OPLOCK_LEVEL_NONE; struct cifs_open_parms oparms; struct smb2_query_directory_rsp *qd_rsp = NULL; + struct smb2_query_directory_rsp *qd2_rsp = NULL; struct smb2_create_rsp *op_rsp = NULL; struct TCP_Server_Info *server; int retries = 0, cur_sleep = 0; + unsigned int compound_resp_bufsize; replay_again: /* reinitialize for possible replay */ @@ -2476,8 +2479,15 @@ smb2_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon, if (smb3_encryption_required(tcon)) flags |= CIFS_TRANSFORM_REQ; + /* + * Clamp compound Create+QD1+QD2 response sizing to a response size + * for suited for one credit even if CIFSMaxBufSize is tuned larger + */ + compound_resp_bufsize = min_t(unsigned int, CIFSMaxBufSize, + SMB2_MAX_BUFFER_SIZE); + memset(rqst, 0, sizeof(rqst)); - resp_buftype[0] = resp_buftype[1] = CIFS_NO_BUFFER; + resp_buftype[0] = resp_buftype[1] = resp_buftype[2] = CIFS_NO_BUFFER; memset(rsp_iov, 0, sizeof(rsp_iov)); /* Open */ @@ -2501,7 +2511,7 @@ smb2_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon, goto qdf_free; smb2_set_next_command(tcon, &rqst[0]); - /* Query directory */ + /* First Query directory */ srch_inf->entries_in_buffer = 0; srch_inf->index_of_last_entry = 2; @@ -2512,11 +2522,27 @@ smb2_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon, rc = SMB2_query_directory_init(xid, tcon, server, &rqst[1], COMPOUND_FID, COMPOUND_FID, - 0, srch_inf->info_level); + 0, srch_inf->info_level, + SMB2_QD1_OUTPUT_SIZE(compound_resp_bufsize)); if (rc) goto qdf_free; smb2_set_related(&rqst[1]); + smb2_set_next_command(tcon, &rqst[1]); + + /* Second Query directory - minimal size to check if more data exists */ + memset(&qd2_iov, 0, sizeof(qd2_iov)); + rqst[2].rq_iov = qd2_iov; + rqst[2].rq_nvec = SMB2_QUERY_DIRECTORY_IOV_SIZE; + + rc = SMB2_query_directory_init(xid, tcon, server, + &rqst[2], + COMPOUND_FID, COMPOUND_FID, + 0, srch_inf->info_level, SMB2_QD2_RESPONSE_SIZE); + if (rc) + goto qdf_free; + + smb2_set_related(&rqst[2]); if (retries) { /* Back-off before retry */ @@ -2524,10 +2550,11 @@ smb2_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon, msleep(cur_sleep); smb2_set_replay(server, &rqst[0]); smb2_set_replay(server, &rqst[1]); + smb2_set_replay(server, &rqst[2]); } rc = compound_send_recv(xid, tcon->ses, server, - flags, 2, rqst, + flags, 3, rqst, resp_buftype, rsp_iov); /* If the open failed there is nothing to do */ @@ -2559,14 +2586,111 @@ smb2_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon, goto qdf_free; } - rc = smb2_parse_query_directory(tcon, &rsp_iov[1], resp_buftype[1], - srch_inf); - if (rc) { - trace_smb3_query_dir_err(xid, fid->persistent_fid, tcon->tid, - tcon->ses->Suid, 0, 0, rc); - goto qdf_free; + qd2_rsp = (struct smb2_query_directory_rsp *)rsp_iov[2].iov_base; + + /* + * If QD2 has data, combine QD1 and QD2 responses before parsing. + * The server cursor advances past both responses, so we can't discard QD2. + */ + if (qd2_rsp && qd2_rsp->hdr.Status == STATUS_SUCCESS && + le32_to_cpu(qd2_rsp->OutputBufferLength) > 0) { + char *combined_buf; + size_t qd1_data_len, qd2_data_len, combined_len; + u16 qd1_offset, qd2_offset; + struct smb2_query_directory_rsp *combined_rsp; + struct kvec combined_iov; + FILE_DIRECTORY_INFO *last_entry_in_qd1; + char *qd1_entries_start, *qd2_entries_start; + unsigned int next_offset; + + qd1_offset = le16_to_cpu(qd_rsp->OutputBufferOffset); + qd2_offset = le16_to_cpu(qd2_rsp->OutputBufferOffset); + qd1_data_len = le32_to_cpu(qd_rsp->OutputBufferLength); + qd2_data_len = le32_to_cpu(qd2_rsp->OutputBufferLength); + + /* Allocate buffer for: QD1 header + QD1 data + QD2 data */ + combined_len = qd1_offset + qd1_data_len + qd2_data_len; + combined_buf = kmalloc(combined_len, GFP_KERNEL); + if (!combined_buf) { + rc = -ENOMEM; + goto qdf_free; + } + + /* Copy QD1 header and data */ + memcpy(combined_buf, qd_rsp, qd1_offset + qd1_data_len); + + /* Append QD2 data (directory entries only, not the header) */ + memcpy(combined_buf + qd1_offset + qd1_data_len, + (char *)qd2_rsp + qd2_offset, qd2_data_len); + + /* Update OutputBufferLength to reflect combined data */ + combined_rsp = (struct smb2_query_directory_rsp *)combined_buf; + combined_rsp->OutputBufferLength = cpu_to_le32(qd1_data_len + qd2_data_len); + + /* + * Chain QD1 and QD2 entries: find the last entry in QD1 and update + * its NextEntryOffset to point to the first entry in QD2. + */ + if (qd1_data_len > 0) { + qd1_entries_start = combined_buf + qd1_offset; + qd2_entries_start = combined_buf + qd1_offset + qd1_data_len; + last_entry_in_qd1 = (FILE_DIRECTORY_INFO *)qd1_entries_start; + + /* Walk QD1 entries to find the last one with bounds checking */ + while (1) { + char *end_of_qd1 = qd1_entries_start + qd1_data_len; + + next_offset = le32_to_cpu(last_entry_in_qd1->NextEntryOffset); + if (next_offset == 0) + break; /* Found last entry */ + + /* Bounds check before advancing */ + if ((char *)last_entry_in_qd1 + next_offset >= end_of_qd1) { + cifs_dbg(VFS, "query_dir_first: invalid NextEntryOffset in QD1\n"); + kfree(combined_buf); + rc = -EIO; + goto qdf_free; + } + + last_entry_in_qd1 = (FILE_DIRECTORY_INFO *)((char *)last_entry_in_qd1 + next_offset); + } + + /* Chain last QD1 entry to first QD2 entry */ + last_entry_in_qd1->NextEntryOffset = cpu_to_le32(qd2_entries_start - (char *)last_entry_in_qd1); + } + + /* Parse the combined buffer */ + combined_iov.iov_base = combined_buf; + combined_iov.iov_len = combined_len; + rc = smb2_parse_query_directory(tcon, &combined_iov, CIFS_DYNAMIC_BUFFER, + srch_inf); + if (rc) { + kfree(combined_buf); + trace_smb3_query_dir_err(xid, fid->persistent_fid, tcon->tid, + tcon->ses->Suid, 0, 0, rc); + goto qdf_free; + } + /* Ownership of combined_buf transferred to srch_inf->ntwrk_buf_start */ + srch_inf->endOfSearch = false; + cifs_dbg(FYI, "query_dir_first: combined QD1 and QD2, %d entries\n", + srch_inf->entries_in_buffer); + } else { + /* No data in QD2, just parse QD1 */ + rc = smb2_parse_query_directory(tcon, &rsp_iov[1], resp_buftype[1], + srch_inf); + if (rc) { + trace_smb3_query_dir_err(xid, fid->persistent_fid, tcon->tid, + tcon->ses->Suid, 0, 0, rc); + goto qdf_free; + } + resp_buftype[1] = CIFS_NO_BUFFER; + + /* Check if QD2 indicates end of directory */ + if (qd2_rsp && qd2_rsp->hdr.Status == STATUS_NO_MORE_FILES) { + srch_inf->endOfSearch = true; + cifs_dbg(FYI, "query_dir_first: small directory, all entries read\n"); + } } - resp_buftype[1] = CIFS_NO_BUFFER; trace_smb3_query_dir_done(xid, fid->persistent_fid, tcon->tid, tcon->ses->Suid, 0, srch_inf->entries_in_buffer); @@ -2575,8 +2699,10 @@ smb2_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon, kfree(utf16_path); SMB2_open_free(&rqst[0]); SMB2_query_directory_free(&rqst[1]); + SMB2_query_directory_free(&rqst[2]); free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base); free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base); + free_rsp_buf(resp_buftype[2], rsp_iov[2].iov_base); if (is_replayable_error(rc) && smb2_should_replay(tcon, &retries, &cur_sleep)) diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c index 49dca84b169e6..2d55246d2851b 100644 --- a/fs/smb/client/smb2pdu.c +++ b/fs/smb/client/smb2pdu.c @@ -5504,18 +5504,27 @@ int SMB2_query_directory_init(const unsigned int xid, struct TCP_Server_Info *server, struct smb_rqst *rqst, u64 persistent_fid, u64 volatile_fid, - int index, int info_level) + int index, int info_level, + unsigned int output_size) { struct smb2_query_directory_req *req; unsigned char *bufptr; __le16 asteriks = cpu_to_le16('*'); - unsigned int output_size = CIFSMaxBufSize - - MAX_SMB2_CREATE_RESPONSE_SIZE - - MAX_SMB2_CLOSE_RESPONSE_SIZE; unsigned int total_len; struct kvec *iov = rqst->rq_iov; int len, rc; + /* + * Use provided output_size, or default to CIFSMaxBufSize calculation. + * The default is for standalone QueryDir (smb2_query_dir_next). + * For compounds, the caller should pass explicit output_size. + */ + if (output_size == 0) { + output_size = CIFSMaxBufSize - + MAX_SMB2_CREATE_RESPONSE_SIZE - + MAX_SMB2_CLOSE_RESPONSE_SIZE; + } + rc = smb2_plain_req_init(SMB2_QUERY_DIRECTORY, tcon, server, (void **) &req, &total_len); if (rc) @@ -5697,7 +5706,7 @@ SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon, rc = SMB2_query_directory_init(xid, tcon, server, &rqst, persistent_fid, volatile_fid, index, - srch_inf->info_level); + srch_inf->info_level, 0); if (rc) goto qdir_exit; diff --git a/fs/smb/client/smb2pdu.h b/fs/smb/client/smb2pdu.h index 30d70097fe2fa..7b7a864520c68 100644 --- a/fs/smb/client/smb2pdu.h +++ b/fs/smb/client/smb2pdu.h @@ -129,6 +129,17 @@ struct share_redirect_error_context_rsp { */ #define MAX_SMB2_CREATE_RESPONSE_SIZE 880 +/* Size of the minimal QueryDir response for checking if more data exists */ +#define SMB2_QD2_RESPONSE_SIZE 4096 + +/* + * Output buffer size for first QueryDir in Create+QD1+QD2 compound. + * Accounts for shared buffer space needed for all three responses. + */ +#define SMB2_QD1_OUTPUT_SIZE(bufsize) \ + ((bufsize) - MAX_SMB2_CREATE_RESPONSE_SIZE - \ + sizeof(struct smb2_hdr) - SMB2_QD2_RESPONSE_SIZE) + #define SMB2_LEASE_READ_CACHING_HE 0x01 #define SMB2_LEASE_HANDLE_CACHING_HE 0x02 #define SMB2_LEASE_WRITE_CACHING_HE 0x04 diff --git a/fs/smb/client/smb2proto.h b/fs/smb/client/smb2proto.h index 230bb1e9f4e19..9de7d2fe8d466 100644 --- a/fs/smb/client/smb2proto.h +++ b/fs/smb/client/smb2proto.h @@ -194,7 +194,8 @@ int SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon, int SMB2_query_directory_init(const unsigned int xid, struct cifs_tcon *tcon, struct TCP_Server_Info *server, struct smb_rqst *rqst, u64 persistent_fid, - u64 volatile_fid, int index, int info_level); + u64 volatile_fid, int index, int info_level, + unsigned int output_size); void SMB2_query_directory_free(struct smb_rqst *rqst); int SMB2_set_eof(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_fid, u64 volatile_fid, u32 pid, -- 2.43.0