rc = super_setup_bdi(sb);
if (rc)
goto out_no_root;
- /* tune readahead according to rsize */
- sb->s_bdi->ra_pages = cifs_sb->ctx->rsize / PAGE_SIZE;
+ /* tune readahead according to rsize if readahead size not set on mount */
+ if (cifs_sb->ctx->rasize)
+ sb->s_bdi->ra_pages = cifs_sb->ctx->rasize / PAGE_SIZE;
+ else
+ sb->s_bdi->ra_pages = cifs_sb->ctx->rsize / PAGE_SIZE;
sb->s_blocksize = CIFS_MAX_MSGSIZE;
sb->s_blocksize_bits = 14; /* default 2**14 = CIFS_MAX_MSGSIZE */
seq_printf(s, ",rsize=%u", cifs_sb->ctx->rsize);
seq_printf(s, ",wsize=%u", cifs_sb->ctx->wsize);
seq_printf(s, ",bsize=%u", cifs_sb->ctx->bsize);
+ if (cifs_sb->ctx->rasize)
+ seq_printf(s, ",rasize=%u", cifs_sb->ctx->rasize);
if (tcon->ses->server->min_offload)
seq_printf(s, ",esize=%u", tcon->ses->server->min_offload);
seq_printf(s, ",echo_interval=%lu",
fsparam_u32("min_enc_offload", Opt_min_enc_offload),
fsparam_u32("esize", Opt_min_enc_offload),
fsparam_u32("bsize", Opt_blocksize),
+ fsparam_u32("rasize", Opt_rasize),
fsparam_u32("rsize", Opt_rsize),
fsparam_u32("wsize", Opt_wsize),
fsparam_u32("actimeo", Opt_actimeo),
ctx->bsize = result.uint_32;
ctx->got_bsize = true;
break;
+ case Opt_rasize:
+ /*
+ * readahead size realistically should never need to be
+ * less than 1M (CIFS_DEFAULT_IOSIZE) or greater than 32M
+ * (perhaps an exception should be considered in the
+ * for the case of a large number of channels
+ * when multichannel is negotiated) since that would lead
+ * to plenty of parallel I/O in flight to the server.
+ * Note that smaller read ahead sizes would
+ * hurt performance of common tools like cp and scp
+ * which often trigger sequential i/o with read ahead
+ */
+ if ((result.uint_32 > (8 * SMB3_DEFAULT_IOSIZE)) ||
+ (result.uint_32 < CIFS_DEFAULT_IOSIZE)) {
+ cifs_errorf(fc, "%s: Invalid rasize %d vs. %d\n",
+ __func__, result.uint_32, SMB3_DEFAULT_IOSIZE);
+ goto cifs_parse_mount_err;
+ }
+ ctx->rasize = result.uint_32;
+ break;
case Opt_rsize:
ctx->rsize = result.uint_32;
ctx->got_rsize = true;
ctx->cred_uid = current_uid();
ctx->linux_uid = current_uid();
ctx->linux_gid = current_gid();
- ctx->bsize = 1024 * 1024; /* can improve cp performance significantly */
+ /* By default 4MB read ahead size, 1MB block size */
+ ctx->bsize = CIFS_DEFAULT_IOSIZE; /* can improve cp performance significantly */
+ ctx->rasize = 0; /* 0 = use default (ie negotiated rsize) for read ahead pages */
/*
* default to SFM style remapping of seven reserved characters