Added additional patch to add "acregmax" so now behavior is more similar to nfs.
"acregmax" changes file metadata caching timeout
"acdirmax" changes directory metadata caching
"actimeo" does what it did before - and changes both.
On Wed, Feb 24, 2021 at 11:31 AM Steve French <smfrench@xxxxxxxxx> wrote:
>
> On Wed, Feb 24, 2021 at 10:11 AM Tom Talpey <tom@xxxxxxxxxx> wrote:
> >
> > On 2/23/2021 8:03 PM, Steve French wrote:
> > > Updated version incorporates Ronnie's suggestion of leaving the
> > > default (for directory caching) the same as it is today, 1 second, to
> > > avoid
> > > unnecessary risk. Most users can safely improve performance by
> > > mounting with acdirmax to a higher value (e.g. 60 seconds as NFS
> > > defaults to).
> > >
> > > nfs and cifs on Linux currently have a mount parameter "actimeo" to control
> > > metadata (attribute) caching but cifs does not have additional mount
> > > parameters to allow distinguishing between caching directory metadata
> > > (e.g. needed to revalidate paths) and that for files.
> >
> > The behaviors seem to be slightly different with this change.
> > With NFS, the actimeo option overrides the four min/max options,
> > and by default the directory ac timers range between 30 and 60.
> >
> > The CIFS code I see below seems to completely separate actimeo
> > and acdirmax, and if not set, uses the historic 1 second value.
> > That's fine, but it's completely different from NFS. Shouldn't we
> > use a different mount option, to avoid confusing the admin?
>
> Ugh ... You are probably right. I was trying to avoid two problems:
> 1) (a minor one) adding a second mount option rather than just one (to
> solve the same problem). But reducing confusion is worth an extra
> mount option
>
> 2) how to avoid the user specifying *both* actimeo and acregmax -
> which one 'wins' (presumably the last one in the mount line)
> We could check for this and warn the user in mount.cifs so maybe not
> important to worry about in the kernel though.
>
> I will add the acregmax mount option and change actimeo to mean
> if (actimeo is set)
> acregmax = acdirmax = actimeo
>
>
> --
> Thanks,
>
> Steve
--
Thanks,
Steve
From bfe9d6d26de6f30d38b206d2676109660931ad4e Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@xxxxxxxxxxxxx>
Date: Wed, 24 Feb 2021 12:12:53 -0600
Subject: [PATCH] cifs: Add new parameter "acregmax" for distinct file and
directory metadata timeout
The new optional mount parameter "acregmax" allows a different
timeout for file metadata ("acdirmax" now allows controlling timeout
for directory metadata). Setting "actimeo" still works as before,
and changes timeout for both files and directories, but
specifying "acregmax" or "acdirmax" allows overriding the
default more granularly which can be a big performance benefit
on some workloads. "acregmax" is already used by NFS as a mount
parameter (albeit with a larger default and thus looser caching).
Suggested-by: Tom Talpey <tom@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/cifs/cifsfs.c | 15 ++++++++++++---
fs/cifs/connect.c | 2 +-
fs/cifs/fs_context.c | 23 ++++++++++++++++++-----
fs/cifs/fs_context.h | 6 ++++--
fs/cifs/inode.c | 4 ++--
5 files changed, 37 insertions(+), 13 deletions(-)
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 4e0b0b26e844..3b61f09f3e1b 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -637,9 +637,18 @@ cifs_show_options(struct seq_file *s, struct dentry *root)
seq_printf(s, ",snapshot=%llu", tcon->snapshot_time);
if (tcon->handle_timeout)
seq_printf(s, ",handletimeout=%u", tcon->handle_timeout);
- /* convert actimeo and directory attribute timeout and display in seconds */
- seq_printf(s, ",actimeo=%lu", cifs_sb->ctx->actimeo / HZ);
- seq_printf(s, ",acdirmax=%lu", cifs_sb->ctx->acdirmax / HZ);
+
+ /*
+ * Display file and directory attribute timeout in seconds.
+ * If file and directory attribute timeout the same then actimeo
+ * was likely specified on mount
+ */
+ if (cifs_sb->ctx->acdirmax == cifs_sb->ctx->acregmax)
+ seq_printf(s, ",actimeo=%lu", cifs_sb->ctx->acregmax / HZ);
+ else {
+ seq_printf(s, ",acdirmax=%lu", cifs_sb->ctx->acdirmax / HZ);
+ seq_printf(s, ",acregmax=%lu", cifs_sb->ctx->acregmax / HZ);
+ }
if (tcon->ses->chan_max > 1)
seq_printf(s, ",multichannel,max_channels=%zu",
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index a9dc39aee9f4..9ecd8098c2b6 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2276,7 +2276,7 @@ compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
if (strcmp(old->local_nls->charset, new->local_nls->charset))
return 0;
- if (old->ctx->actimeo != new->ctx->actimeo)
+ if (old->ctx->acregmax != new->ctx->acregmax)
return 0;
if (old->ctx->acdirmax != new->ctx->acdirmax)
return 0;
diff --git a/fs/cifs/fs_context.c b/fs/cifs/fs_context.c
index f3be07f4671d..14c955a30006 100644
--- a/fs/cifs/fs_context.c
+++ b/fs/cifs/fs_context.c
@@ -141,6 +141,7 @@ const struct fs_parameter_spec smb3_fs_parameters[] = {
fsparam_u32("wsize", Opt_wsize),
fsparam_u32("actimeo", Opt_actimeo),
fsparam_u32("acdirmax", Opt_acdirmax),
+ fsparam_u32("acregmax", Opt_acregmax),
fsparam_u32("echo_interval", Opt_echo_interval),
fsparam_u32("max_credits", Opt_max_credits),
fsparam_u32("handletimeout", Opt_handletimeout),
@@ -930,10 +931,10 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
ctx->wsize = result.uint_32;
ctx->got_wsize = true;
break;
- case Opt_actimeo:
- ctx->actimeo = HZ * result.uint_32;
- if (ctx->actimeo > CIFS_MAX_ACTIMEO) {
- cifs_dbg(VFS, "attribute cache timeout too large\n");
+ case Opt_acregmax:
+ ctx->acregmax = HZ * result.uint_32;
+ if (ctx->acregmax > CIFS_MAX_ACTIMEO) {
+ cifs_dbg(VFS, "acregmax too large\n");
goto cifs_parse_mount_err;
}
break;
@@ -944,6 +945,18 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
goto cifs_parse_mount_err;
}
break;
+ case Opt_actimeo:
+ if (HZ * result.uint_32 > CIFS_MAX_ACTIMEO) {
+ cifs_dbg(VFS, "timeout too large\n");
+ goto cifs_parse_mount_err;
+ }
+ if ((ctx->acdirmax != CIFS_DEF_ACTIMEO) ||
+ (ctx->acregmax != CIFS_DEF_ACTIMEO)) {
+ cifs_dbg(VFS, "actimeo ignored since acregmax or acdirmax specified\n");
+ break;
+ }
+ ctx->acdirmax = ctx->acregmax = HZ * result.uint_32;
+ break;
case Opt_echo_interval:
ctx->echo_interval = result.uint_32;
break;
@@ -1369,7 +1382,7 @@ int smb3_init_fs_context(struct fs_context *fc)
/* default is to use strict cifs caching semantics */
ctx->strict_io = true;
- ctx->actimeo = CIFS_DEF_ACTIMEO;
+ ctx->acregmax = CIFS_DEF_ACTIMEO;
ctx->acdirmax = CIFS_DEF_ACTIMEO;
/* Most clients set timeout to 0, allows server to use its default */
diff --git a/fs/cifs/fs_context.h b/fs/cifs/fs_context.h
index 472372fec4e9..87dd1f7168f2 100644
--- a/fs/cifs/fs_context.h
+++ b/fs/cifs/fs_context.h
@@ -119,6 +119,7 @@ enum cifs_param {
Opt_wsize,
Opt_actimeo,
Opt_acdirmax,
+ Opt_acregmax,
Opt_echo_interval,
Opt_max_credits,
Opt_snapshot,
@@ -233,8 +234,9 @@ struct smb3_fs_context {
unsigned int wsize;
unsigned int min_offload;
bool sockopt_tcp_nodelay:1;
- unsigned long actimeo; /* attribute cache timeout for files (jiffies) */
- unsigned long acdirmax; /* attribute cache timeout for directories (jiffies) */
+ /* attribute cache timemout for files and directories in jiffies */
+ unsigned long acregmax;
+ unsigned long acdirmax;
struct smb_version_operations *ops;
struct smb_version_values *vals;
char *prepath;
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index cfd31cc4520f..0b0b01ef3ecb 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -2209,10 +2209,10 @@ cifs_inode_needs_reval(struct inode *inode)
cifs_i->time + cifs_sb->ctx->acdirmax))
return true;
} else { /* file */
- if (!cifs_sb->ctx->actimeo)
+ if (!cifs_sb->ctx->acregmax)
return true;
if (!time_in_range(jiffies, cifs_i->time,
- cifs_i->time + cifs_sb->ctx->actimeo))
+ cifs_i->time + cifs_sb->ctx->acregmax))
return true;
}
--
2.27.0
