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smb3: allow parallelizing decryption of reads

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decrypting large reads on encrypted shares can be slow (e.g. adding
multiple milliseconds per-read on non-GCM capable servers or
when mounting with dialects prior to SMB3.1.1) - allow parallelizing
of read decryption by launching worker threads.

Testing to Samba on localhost showed 25% improvement.
Testing to remote server showed very large improvement when
doing more than one 'cp' command was called at one time.

Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
This commit is contained in:
Steve French 2019-09-07 01:09:49 -05:00
parent 3175eb9b57
commit 35cf94a397
3 changed files with 97 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
fs/cifs/cifsfs.c
View File

@ -109,6 +109,7 @@ extern mempool_t *cifs_req_poolp;
extern mempool_t *cifs_mid_poolp;
struct workqueue_struct *cifsiod_wq;
struct workqueue_struct *decrypt_wq;
struct workqueue_struct *cifsoplockd_wq;
__u32 cifs_lock_secret;
@ -1499,11 +1500,22 @@ init_cifs(void)
goto out_clean_proc;
}
/*
* BB Consider setting limit!=0 maybe to min(num_of_cores - 1, 3) so we
* don't launch too many worker threads
*/
decrypt_wq = alloc_workqueue("smb3decryptd",
WQ_FREEZABLE|WQ_MEM_RECLAIM, 0);
if (!decrypt_wq) {
rc = -ENOMEM;
goto out_destroy_cifsiod_wq;
}
cifsoplockd_wq = alloc_workqueue("cifsoplockd",
WQ_FREEZABLE|WQ_MEM_RECLAIM, 0);
if (!cifsoplockd_wq) {
rc = -ENOMEM;
goto out_destroy_cifsiod_wq;
goto out_destroy_decrypt_wq;
}
rc = cifs_fscache_register();
@ -1569,6 +1581,8 @@ out_unreg_fscache:
cifs_fscache_unregister();
out_destroy_cifsoplockd_wq:
destroy_workqueue(cifsoplockd_wq);
out_destroy_decrypt_wq:
destroy_workqueue(decrypt_wq);
out_destroy_cifsiod_wq:
destroy_workqueue(cifsiod_wq);
out_clean_proc:
@ -1595,6 +1609,7 @@ exit_cifs(void)
cifs_destroy_inodecache();
cifs_fscache_unregister();
destroy_workqueue(cifsoplockd_wq);
destroy_workqueue(decrypt_wq);
destroy_workqueue(cifsiod_wq);
cifs_proc_clean();
}

1
fs/cifs/cifsglob.h
View File

@ -1892,6 +1892,7 @@ void cifs_queue_oplock_break(struct cifsFileInfo *cfile);
extern const struct slow_work_ops cifs_oplock_break_ops;
extern struct workqueue_struct *cifsiod_wq;
extern struct workqueue_struct *decrypt_wq;
extern struct workqueue_struct *cifsoplockd_wq;
extern __u32 cifs_lock_secret;

83
fs/cifs/smb2ops.c
View File

@ -4017,8 +4017,58 @@ handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid,
return length;
}
struct smb2_decrypt_work {
struct work_struct decrypt;
struct TCP_Server_Info *server;
struct page **ppages;
char *buf;
unsigned int npages;
unsigned int len;
};
static void smb2_decrypt_offload(struct work_struct *work)
{
struct smb2_decrypt_work *dw = container_of(work,
struct smb2_decrypt_work, decrypt);
int i, rc;
struct mid_q_entry *mid;
rc = decrypt_raw_data(dw->server, dw->buf, dw->server->vals->read_rsp_size,
dw->ppages, dw->npages, dw->len);
if (rc) {
cifs_dbg(VFS, "error decrypting rc=%d\n", rc);
goto free_pages;
}
mid = smb2_find_mid(dw->server, dw->buf);
if (mid == NULL)
cifs_dbg(FYI, "mid not found\n");
else {
mid->decrypted = true;
rc = handle_read_data(dw->server, mid, dw->buf,
dw->server->vals->read_rsp_size,
dw->ppages, dw->npages, dw->len);
}
dw->server->lstrp = jiffies;
mid->callback(mid);
cifs_mid_q_entry_release(mid);
free_pages:
for (i = dw->npages-1; i >= 0; i--)
put_page(dw->ppages[i]);
kfree(dw->ppages);
cifs_small_buf_release(dw->buf);
}
static int
receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid)
receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid,
int *num_mids)
{
char *buf = server->smallbuf;
struct smb2_transform_hdr *tr_hdr = (struct smb2_transform_hdr *)buf;
@ -4028,7 +4078,9 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid)
unsigned int buflen = server->pdu_size;
int rc;
int i = 0;
struct smb2_decrypt_work *dw;
*num_mids = 1;
len = min_t(unsigned int, buflen, server->vals->read_rsp_size +
sizeof(struct smb2_transform_hdr)) - HEADER_SIZE(server) + 1;
@ -4064,6 +4116,32 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid)
if (rc)
goto free_pages;
/*
* For large reads, offload to different thread for better performance,
* use more cores decrypting which can be expensive
*/
/* TODO: make the size limit to enable decrypt offload configurable */
if (server->pdu_size > (512 * 1024)) {
dw = kmalloc(sizeof(struct smb2_decrypt_work), GFP_KERNEL);
if (dw == NULL)
goto non_offloaded_decrypt;
dw->buf = server->smallbuf;
server->smallbuf = (char *)cifs_small_buf_get();
INIT_WORK(&dw->decrypt, smb2_decrypt_offload);
dw->npages = npages;
dw->server = server;
dw->ppages = pages;
dw->len = len;
queue_work(cifsiod_wq, &dw->decrypt);
*num_mids = 0; /* worker thread takes care of finding mid */
return -1;
}
non_offloaded_decrypt:
rc = decrypt_raw_data(server, buf, server->vals->read_rsp_size,
pages, npages, len);
if (rc)
@ -4210,8 +4288,7 @@ smb3_receive_transform(struct TCP_Server_Info *server,
/* TODO: add support for compounds containing READ. */
if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server)) {
*num_mids = 1;
return receive_encrypted_read(server, &mids[0]);
return receive_encrypted_read(server, &mids[0], num_mids);
}
return receive_encrypted_standard(server, mids, bufs, num_mids);