Replace hardcoded alignment computations (e.g. (len + 7) & ~0x7) of
(mostly) SMB2 messages length by ALIGN()/IS_ALIGNED() macros (right
tools for the job, less prone to errors).
But also replace (DIV_ROUND_UP(len, 8) * 8) with ALIGN(len, 8), which,
if not optimized by the compiler, has the overhead of a multiplication
and a division. Do the same for roundup() by replacing it by round_up()
(division-less version, but requires the multiple to be a power of 2,
which is always the case for us).
Also remove some unecessary checks where !IS_ALIGNED() would fit, but
calling round_up() directly is just fine as it'll be a no-op if the
value is already aligned.
Afraid this was a useless micro-optimization, I ran some tests with a
very light workload, and I observed a ~50% perf improvement already:
Record all cifs.ko functions:
# trace-cmd record --module cifs -p function_graph
(test-dir has ~50MB with ~4000 files)
Test commands after share is mounted and with no activity:
# cp -r test-dir /mnt/test
# sync
# umount /mnt/test
Number of traced functions:
# trace-cmd report -l | awk '{ print $6 }' | grep "^[0-9].*" | wc -l
- unpatched: 307746
- patched: 313199
Measuring the average latency of all traced functions:
# trace-cmd report -l | awk '{ print $6 }' | grep "^[0-9].*" | jq -s add/length
- unpatched: 27105.577791262822 us
- patched: 14548.665733635338 us
So even though the patched version made 5k+ more function calls (for
whatever reason), it still did it with ~50% reduced latency.
On a larger scale, given the affected code paths, this patch should
show a relevant improvement.
Signed-off-by: Enzo Matsumiya <ematsumiya@xxxxxxx>
---
Please let me know if my measurements are enough/valid.
fs/cifs/cifssmb.c | 7 +++---
fs/cifs/connect.c | 11 ++++++--
fs/cifs/sess.c | 18 +++++--------
fs/cifs/smb2inode.c | 4 +--
fs/cifs/smb2misc.c | 2 +-
fs/cifs/smb2pdu.c | 61 +++++++++++++++++++--------------------------
6 files changed, 47 insertions(+), 56 deletions(-)
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 7aa91e272027..addf3fc62aef 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -2305,7 +2305,7 @@ int CIFSSMBRenameOpenFile(const unsigned int xid, struct cifs_tcon *pTcon,
remap);
}
rename_info->target_name_len = cpu_to_le32(2 * len_of_str);
- count = 12 /* sizeof(struct set_file_rename) */ + (2 * len_of_str);
+ count = sizeof(struct set_file_rename) + (2 * len_of_str);
byte_count += count;
pSMB->DataCount = cpu_to_le16(count);
pSMB->TotalDataCount = pSMB->DataCount;
@@ -2796,7 +2796,7 @@ CIFSSMBQuerySymLink(const unsigned int xid, struct cifs_tcon *tcon,
cifs_dbg(FYI, "Invalid return data count on get reparse info ioctl\n");
goto qreparse_out;
}
- end_of_smb = 2 + get_bcc(&pSMBr->hdr) + (char *)&pSMBr->ByteCount;
+ end_of_smb = sizeof(__le16) + get_bcc(&pSMBr->hdr) + (char *)&pSMBr->ByteCount;
reparse_buf = (struct reparse_symlink_data *)
((char *)&pSMBr->hdr.Protocol + data_offset);
if ((char *)reparse_buf >= end_of_smb) {
@@ -3350,8 +3350,7 @@ validate_ntransact(char *buf, char **ppparm, char **ppdata,
pSMBr = (struct smb_com_ntransact_rsp *)buf;
bcc = get_bcc(&pSMBr->hdr);
- end_of_smb = 2 /* sizeof byte count */ + bcc +
- (char *)&pSMBr->ByteCount;
+ end_of_smb = sizeof(__le16) + bcc + (char *)&pSMBr->ByteCount;
data_offset = le32_to_cpu(pSMBr->DataOffset);
data_count = le32_to_cpu(pSMBr->DataCount);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index a0a06b6f252b..389127e21563 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2833,9 +2833,12 @@ ip_rfc1001_connect(struct TCP_Server_Info *server)
* sessinit is sent but no second negprot
*/
struct rfc1002_session_packet *ses_init_buf;
+ unsigned int req_noscope_len;
struct smb_hdr *smb_buf;
+
ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
GFP_KERNEL);
+
if (ses_init_buf) {
ses_init_buf->trailer.session_req.called_len = 32;
@@ -2871,8 +2874,12 @@ ip_rfc1001_connect(struct TCP_Server_Info *server)
ses_init_buf->trailer.session_req.scope2 = 0;
smb_buf = (struct smb_hdr *)ses_init_buf;
- /* sizeof RFC1002_SESSION_REQUEST with no scope */
- smb_buf->smb_buf_length = cpu_to_be32(0x81000044);
+ /* sizeof RFC1002_SESSION_REQUEST with no scopes */
+ req_noscope_len = sizeof(struct rfc1002_session_packet) - 2;
+
+ /* == cpu_to_be32(0x81000044) */
+ smb_buf->smb_buf_length =
+ cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | req_noscope_len);
rc = smb_send(server, smb_buf, 0x44);
kfree(ses_init_buf);
/*
diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index 3af3b05b6c74..951874928d70 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -601,11 +601,6 @@ static void unicode_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
/* BB FIXME add check that strings total less
than 335 or will need to send them as arrays */
- /* unicode strings, must be word aligned before the call */
-/* if ((long) bcc_ptr % 2) {
- *bcc_ptr = 0;
- bcc_ptr++;
- } */
/* copy user */
if (ses->user_name == NULL) {
/* null user mount */
@@ -1318,7 +1313,7 @@ sess_auth_ntlmv2(struct sess_data *sess_data)
}
if (ses->capabilities & CAP_UNICODE) {
- if (sess_data->iov[0].iov_len % 2) {
+ if (!IS_ALIGNED(sess_data->iov[0].iov_len, 2)) {
*bcc_ptr = 0;
bcc_ptr++;
}
@@ -1358,7 +1353,7 @@ sess_auth_ntlmv2(struct sess_data *sess_data)
/* no string area to decode, do nothing */
} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
/* unicode string area must be word-aligned */
- if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
+ if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
++bcc_ptr;
--bytes_remaining;
}
@@ -1442,8 +1437,7 @@ sess_auth_kerberos(struct sess_data *sess_data)
if (ses->capabilities & CAP_UNICODE) {
/* unicode strings must be word aligned */
- if ((sess_data->iov[0].iov_len
- + sess_data->iov[1].iov_len) % 2) {
+ if (!IS_ALIGNED(sess_data->iov[0].iov_len + sess_data->iov[1].iov_len, 2)) {
*bcc_ptr = 0;
bcc_ptr++;
}
@@ -1494,7 +1488,7 @@ sess_auth_kerberos(struct sess_data *sess_data)
/* no string area to decode, do nothing */
} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
/* unicode string area must be word-aligned */
- if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
+ if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
++bcc_ptr;
--bytes_remaining;
}
@@ -1546,7 +1540,7 @@ _sess_auth_rawntlmssp_assemble_req(struct sess_data *sess_data)
bcc_ptr = sess_data->iov[2].iov_base;
/* unicode strings must be word aligned */
- if ((sess_data->iov[0].iov_len + sess_data->iov[1].iov_len) % 2) {
+ if (!IS_ALIGNED(sess_data->iov[0].iov_len + sess_data->iov[1].iov_len, 2)) {
*bcc_ptr = 0;
bcc_ptr++;
}
@@ -1747,7 +1741,7 @@ sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data)
/* no string area to decode, do nothing */
} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
/* unicode string area must be word-aligned */
- if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
+ if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
++bcc_ptr;
--bytes_remaining;
}
diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c
index b83f59051b26..4eefbe574b82 100644
--- a/fs/cifs/smb2inode.c
+++ b/fs/cifs/smb2inode.c
@@ -207,7 +207,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,
rqst[num_rqst].rq_iov = &vars->si_iov[0];
rqst[num_rqst].rq_nvec = 1;
- size[0] = 1; /* sizeof __u8 See MS-FSCC section 2.4.11 */
+ size[0] = sizeof(u8); /* See MS-FSCC section 2.4.11 */
data[0] = &delete_pending[0];
rc = SMB2_set_info_init(tcon, server,
@@ -225,7 +225,7 @@ smb2_compound_op(const unsigned int xid, struct cifs_tcon *tcon,
rqst[num_rqst].rq_iov = &vars->si_iov[0];
rqst[num_rqst].rq_nvec = 1;
- size[0] = 8; /* sizeof __le64 */
+ size[0] = sizeof(__le64);
data[0] = ptr;
rc = SMB2_set_info_init(tcon, server,
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index d73e5672aac4..258b01306d85 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -248,7 +248,7 @@ smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *server)
* Some windows servers (win2016) will pad also the final
* PDU in a compound to 8 bytes.
*/
- if (((calc_len + 7) & ~7) == len)
+ if (ALIGN(calc_len, 8) == len)
return 0;
/*
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 6352ab32c7e7..5da0b596c8a0 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -466,15 +466,14 @@ build_signing_ctxt(struct smb2_signing_capabilities *pneg_ctxt)
/*
* Context Data length must be rounded to multiple of 8 for some servers
*/
- pneg_ctxt->DataLength = cpu_to_le16(DIV_ROUND_UP(
- sizeof(struct smb2_signing_capabilities) -
- sizeof(struct smb2_neg_context) +
- (num_algs * 2 /* sizeof u16 */), 8) * 8);
+ pneg_ctxt->DataLength = cpu_to_le16(ALIGN(sizeof(struct smb2_signing_capabilities) -
+ sizeof(struct smb2_neg_context) +
+ (num_algs * sizeof(u16)), 8));
pneg_ctxt->SigningAlgorithmCount = cpu_to_le16(num_algs);
pneg_ctxt->SigningAlgorithms[0] = cpu_to_le16(SIGNING_ALG_AES_CMAC);
- ctxt_len += 2 /* sizeof le16 */ * num_algs;
- ctxt_len = DIV_ROUND_UP(ctxt_len, 8) * 8;
+ ctxt_len += sizeof(__le16) * num_algs;
+ ctxt_len = ALIGN(ctxt_len, 8);
return ctxt_len;
/* TBD add SIGNING_ALG_AES_GMAC and/or SIGNING_ALG_HMAC_SHA256 */
}
@@ -511,8 +510,7 @@ build_netname_ctxt(struct smb2_netname_neg_context *pneg_ctxt, char *hostname)
/* copy up to max of first 100 bytes of server name to NetName field */
pneg_ctxt->DataLength = cpu_to_le16(2 * cifs_strtoUTF16(pneg_ctxt->NetName, hostname, 100, cp));
/* context size is DataLength + minimal smb2_neg_context */
- return DIV_ROUND_UP(le16_to_cpu(pneg_ctxt->DataLength) +
- sizeof(struct smb2_neg_context), 8) * 8;
+ return ALIGN(le16_to_cpu(pneg_ctxt->DataLength) + sizeof(struct smb2_neg_context), 8);
}
static void
@@ -557,18 +555,18 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
* round up total_len of fixed part of SMB3 negotiate request to 8
* byte boundary before adding negotiate contexts
*/
- *total_len = roundup(*total_len, 8);
+ *total_len = ALIGN(*total_len, 8);
pneg_ctxt = (*total_len) + (char *)req;
req->NegotiateContextOffset = cpu_to_le32(*total_len);
build_preauth_ctxt((struct smb2_preauth_neg_context *)pneg_ctxt);
- ctxt_len = DIV_ROUND_UP(sizeof(struct smb2_preauth_neg_context), 8) * 8;
+ ctxt_len = ALIGN(sizeof(struct smb2_preauth_neg_context), 8);
*total_len += ctxt_len;
pneg_ctxt += ctxt_len;
build_encrypt_ctxt((struct smb2_encryption_neg_context *)pneg_ctxt);
- ctxt_len = DIV_ROUND_UP(sizeof(struct smb2_encryption_neg_context), 8) * 8;
+ ctxt_len = ALIGN(sizeof(struct smb2_encryption_neg_context), 8);
*total_len += ctxt_len;
pneg_ctxt += ctxt_len;
@@ -595,9 +593,7 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
if (server->compress_algorithm) {
build_compression_ctxt((struct smb2_compression_capabilities_context *)
pneg_ctxt);
- ctxt_len = DIV_ROUND_UP(
- sizeof(struct smb2_compression_capabilities_context),
- 8) * 8;
+ ctxt_len = ALIGN(sizeof(struct smb2_compression_capabilities_context), 8);
*total_len += ctxt_len;
pneg_ctxt += ctxt_len;
neg_context_count++;
@@ -780,7 +776,7 @@ static int smb311_decode_neg_context(struct smb2_negotiate_rsp *rsp,
if (rc)
break;
/* offsets must be 8 byte aligned */
- clen = (clen + 7) & ~0x7;
+ clen = ALIGN(clen, 8);
offset += clen + sizeof(struct smb2_neg_context);
len_of_ctxts -= clen;
}
@@ -2413,7 +2409,7 @@ create_sd_buf(umode_t mode, bool set_owner, unsigned int *len)
unsigned int group_offset = 0;
struct smb3_acl acl;
- *len = roundup(sizeof(struct crt_sd_ctxt) + (sizeof(struct cifs_ace) * 4), 8);
+ *len = round_up(sizeof(struct crt_sd_ctxt) + (sizeof(struct cifs_ace) * 4), 8);
if (set_owner) {
/* sizeof(struct owner_group_sids) is already multiple of 8 so no need to round */
@@ -2487,7 +2483,7 @@ create_sd_buf(umode_t mode, bool set_owner, unsigned int *len)
memcpy(aclptr, &acl, sizeof(struct smb3_acl));
buf->ccontext.DataLength = cpu_to_le32(ptr - (__u8 *)&buf->sd);
- *len = roundup(ptr - (__u8 *)buf, 8);
+ *len = round_up((unsigned int)(ptr - (__u8 *)buf), 8);
return buf;
}
@@ -2581,7 +2577,7 @@ alloc_path_with_tree_prefix(__le16 **out_path, int *out_size, int *out_len,
* final path needs to be 8-byte aligned as specified in
* MS-SMB2 2.2.13 SMB2 CREATE Request.
*/
- *out_size = roundup(*out_len * sizeof(__le16), 8);
+ *out_size = round_up(*out_len * sizeof(__le16), 8);
*out_path = kzalloc(*out_size + sizeof(__le16) /* null */, GFP_KERNEL);
if (!*out_path)
return -ENOMEM;
@@ -2687,20 +2683,17 @@ int smb311_posix_mkdir(const unsigned int xid, struct inode *inode,
uni_path_len = (2 * UniStrnlen((wchar_t *)utf16_path, PATH_MAX)) + 2;
/* MUST set path len (NameLength) to 0 opening root of share */
req->NameLength = cpu_to_le16(uni_path_len - 2);
- if (uni_path_len % 8 != 0) {
- copy_size = roundup(uni_path_len, 8);
- copy_path = kzalloc(copy_size, GFP_KERNEL);
- if (!copy_path) {
- rc = -ENOMEM;
- goto err_free_req;
- }
- memcpy((char *)copy_path, (const char *)utf16_path,
- uni_path_len);
- uni_path_len = copy_size;
- /* free before overwriting resource */
- kfree(utf16_path);
- utf16_path = copy_path;
+ copy_size = round_up(uni_path_len, 8);
+ copy_path = kzalloc(copy_size, GFP_KERNEL);
+ if (!copy_path) {
+ rc = -ENOMEM;
+ goto err_free_req;
}
+ memcpy((char *)copy_path, (const char *)utf16_path, uni_path_len);
+ uni_path_len = copy_size;
+ /* free before overwriting resource */
+ kfree(utf16_path);
+ utf16_path = copy_path;
}
iov[1].iov_len = uni_path_len;
@@ -2826,9 +2819,7 @@ SMB2_open_init(struct cifs_tcon *tcon, struct TCP_Server_Info *server,
uni_path_len = (2 * UniStrnlen((wchar_t *)path, PATH_MAX)) + 2;
/* MUST set path len (NameLength) to 0 opening root of share */
req->NameLength = cpu_to_le16(uni_path_len - 2);
- copy_size = uni_path_len;
- if (copy_size % 8 != 0)
- copy_size = roundup(copy_size, 8);
+ copy_size = round_up(uni_path_len, 8);
copy_path = kzalloc(copy_size, GFP_KERNEL);
if (!copy_path)
return -ENOMEM;
@@ -4090,7 +4081,7 @@ smb2_new_read_req(void **buf, unsigned int *total_len,
if (request_type & CHAINED_REQUEST) {
if (!(request_type & END_OF_CHAIN)) {
/* next 8-byte aligned request */
- *total_len = DIV_ROUND_UP(*total_len, 8) * 8;
+ *total_len = ALIGN(*total_len, 8);
shdr->NextCommand = cpu_to_le32(*total_len);
} else /* END_OF_CHAIN */
shdr->NextCommand = 0;
--
2.35.3
