| Message ID | 20221215020155.1619839-15-kuba@kernel.org (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | devlink: code split and structured instance walk | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Clearly marked for net-next, async |
| netdev/fixes_present | success | Fixes tag not required for -next series |
| netdev/subject_prefix | success | Link |
| netdev/cover_letter | success | Series has a cover letter |
| netdev/patch_count | success | Link |
| netdev/header_inline | success | No static functions without inline keyword in header files |
| netdev/build_32bit | success | Errors and warnings before: 2 this patch: 2 |
| netdev/cc_maintainers | success | CCed 6 of 6 maintainers |
| netdev/build_clang | success | Errors and warnings before: 1 this patch: 1 |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Signed-off-by tag matches author and committer |
| netdev/check_selftest | success | No net selftest shell script |
| netdev/verify_fixes | success | No Fixes tag |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 2 this patch: 2 |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 151 lines checked |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/source_inline | success | Was 0 now: 0 |
Thu, Dec 15, 2022 at 03:01:54AM CET, kuba@kernel.org wrote: >Most dumpit implementations walk the devlink instances. >This requires careful lock taking and reference dropping. >Factor the loop out and provide just a callback to handle >a single instance dump. > >Convert one user as an example, other users converted >in the next change. > >Slightly inspired by ethtool netlink code. > >Signed-off-by: Jakub Kicinski <kuba@kernel.org> >--- > net/devlink/basic.c | 55 ++++++++++++++++--------------------- > net/devlink/devl_internal.h | 10 +++++++ > net/devlink/netlink.c | 33 ++++++++++++++++++++++ > 3 files changed, 67 insertions(+), 31 deletions(-) > >diff --git a/net/devlink/basic.c b/net/devlink/basic.c >index c6ad8133fc23..f18d8dcf9751 100644 >--- a/net/devlink/basic.c >+++ b/net/devlink/basic.c >@@ -1219,47 +1219,40 @@ static void devlink_rate_notify(struct devlink_rate *devlink_rate, > 0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL); > } > >-static int devlink_nl_cmd_rate_get_dumpit(struct sk_buff *msg, >- struct netlink_callback *cb) >+static int >+devlink_nl_cmd_rate_get_dumpinst(struct sk_buff *msg, struct devlink *devlink, >+ struct netlink_callback *cb) > { > struct devlink_nl_dump_state *dump = devl_dump_state(cb); >- struct devlink *devlink; >+ struct devlink_rate *devlink_rate; >+ int idx = 0; > int err = 0; > >- devlink_dump_for_each_instance_get(msg, dump, devlink) { >- struct devlink_rate *devlink_rate; >- int idx = 0; >- >- devl_lock(devlink); >- list_for_each_entry(devlink_rate, &devlink->rate_list, list) { >- enum devlink_command cmd = DEVLINK_CMD_RATE_NEW; >- u32 id = NETLINK_CB(cb->skb).portid; >+ list_for_each_entry(devlink_rate, &devlink->rate_list, list) { >+ enum devlink_command cmd = DEVLINK_CMD_RATE_NEW; >+ u32 id = NETLINK_CB(cb->skb).portid; > >- if (idx < dump->idx) { >- idx++; >- continue; >- } >- err = devlink_nl_rate_fill(msg, devlink_rate, cmd, id, >- cb->nlh->nlmsg_seq, >- NLM_F_MULTI, NULL); >- if (err) { >- devl_unlock(devlink); >- devlink_put(devlink); >- dump->idx = idx; >- goto out; >- } >+ if (idx < dump->idx) { > idx++; >+ continue; > } >- devl_unlock(devlink); >- devlink_put(devlink); >+ err = devlink_nl_rate_fill(msg, devlink_rate, cmd, id, >+ cb->nlh->nlmsg_seq, >+ NLM_F_MULTI, NULL); >+ if (err) { >+ dump->idx = idx; >+ break; >+ } >+ idx++; > } >-out: >- if (err != -EMSGSIZE) >- return err; > >- return msg->len; >+ return err; > } > >+const struct devlink_gen_cmd devl_gen_rate_get = { >+ .dump_one = devlink_nl_cmd_rate_get_dumpinst, >+}; >+ > static int devlink_nl_cmd_rate_get_doit(struct sk_buff *skb, > struct genl_info *info) > { >@@ -9130,7 +9123,7 @@ const struct genl_small_ops devlink_nl_ops[56] = { > { > .cmd = DEVLINK_CMD_RATE_GET, > .doit = devlink_nl_cmd_rate_get_doit, >- .dumpit = devlink_nl_cmd_rate_get_dumpit, >+ .dumpit = devlink_instance_iter_dump, > .internal_flags = DEVLINK_NL_FLAG_NEED_RATE, > /* can be retrieved by unprivileged users */ > }, >diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h >index 5adac38454fd..e49b82dd77cd 100644 >--- a/net/devlink/devl_internal.h >+++ b/net/devlink/devl_internal.h >@@ -122,6 +122,11 @@ struct devlink_nl_dump_state { > }; > }; > >+struct devlink_gen_cmd { >+ int (*dump_one)(struct sk_buff *msg, struct devlink *devlink, >+ struct netlink_callback *cb); >+}; >+ > /* Iterate over devlink pointers which were possible to get reference to. > * devlink_put() needs to be called for each iterated devlink pointer > * in loop body in order to release the reference. >@@ -138,6 +143,9 @@ struct devlink *devlink_get_from_attrs(struct net *net, struct nlattr **attrs); > void devlink_notify_unregister(struct devlink *devlink); > void devlink_notify_register(struct devlink *devlink); > >+int devlink_instance_iter_dump(struct sk_buff *msg, >+ struct netlink_callback *cb); >+ > static inline struct devlink_nl_dump_state * > devl_dump_state(struct netlink_callback *cb) > { >@@ -173,6 +181,8 @@ devlink_linecard_get_from_info(struct devlink *devlink, struct genl_info *info); > void devlink_linecard_put(struct devlink_linecard *linecard); > > /* Rates */ >+extern const struct devlink_gen_cmd devl_gen_rate_get; >+ > struct devlink_rate * > devlink_rate_get_from_info(struct devlink *devlink, struct genl_info *info); > struct devlink_rate * >diff --git a/net/devlink/netlink.c b/net/devlink/netlink.c >index ce1a7d674d14..fcf10c288480 100644 >--- a/net/devlink/netlink.c >+++ b/net/devlink/netlink.c >@@ -5,6 +5,7 @@ > */ > > #include <net/genetlink.h> >+#include <net/sock.h> > > #include "devl_internal.h" > >@@ -177,6 +178,38 @@ static void devlink_nl_post_doit(const struct genl_split_ops *ops, > devlink_put(devlink); > } > >+static const struct devlink_gen_cmd *devl_gen_cmds[] = { >+ [DEVLINK_CMD_RATE_GET] = &devl_gen_rate_get, >+}; Instead of having this extra list of ops struct, woudn't it make sence to rather implement this dumpit_one infra directly as a part of generic netlink code? Something like: { .cmd = DEVLINK_CMD_RATE_GET, .doit = devlink_nl_cmd_rate_get_doit, .dumpit_one = devlink_nl_cmd_rate_get_dumpit_one, .dumpit_one_walk = devlink_nl_dumpit_one_walk, .internal_flags = DEVLINK_NL_FLAG_NEED_RATE, /* can be retrieved by unprivileged users */ }, Where devlink_nl_dumpit_one_walk would be basically your devlink_instance_iter_dump(), it would get an extra arg dumpit_one function pointer from generic netlink code to call per item: int devlink_nl_dumpit_one_walk(struct sk_buff *msg, struct netlink_callback *cb, int (*dumpit_one)(struct sk_buff *msg, struct netlink_callback *cb, void *priv)); { const struct genl_dumpit_info *info = genl_dumpit_info(cb); struct devlink_nl_dump_state *dump = devl_dump_state(cb); struct devlink *devlink; int err = 0; devlink_dump_for_each_instance_get(msg, dump, devlink) { devl_lock(devlink); err = dumpit_one(msg, cb, devlink); devl_unlock(devlink); devlink_put(devlink); if (err) break; /* restart sub-object walk for the next instance */ dump->idx = 0; } if (err != -EMSGSIZE) return err; return msg->len; } Or we can avoid .dumpit_one_walk() and just have classic .dumpit() which would get the dumpit_one() pointer cb->dumpit_one (obtainable by a helper doing a proper check-warn_on on null). >+ >+int devlink_instance_iter_dump(struct sk_buff *msg, struct netlink_callback *cb) >+{ >+ const struct genl_dumpit_info *info = genl_dumpit_info(cb); >+ struct devlink_nl_dump_state *dump = devl_dump_state(cb); >+ const struct devlink_gen_cmd *cmd; >+ struct devlink *devlink; >+ int err = 0; >+ >+ cmd = devl_gen_cmds[info->op.cmd]; >+ >+ devlink_dump_for_each_instance_get(msg, dump, devlink) { >+ devl_lock(devlink); >+ err = cmd->dump_one(msg, devlink, cb); >+ devl_unlock(devlink); >+ devlink_put(devlink); >+ >+ if (err) >+ break; >+ >+ /* restart sub-object walk for the next instance */ >+ dump->idx = 0; >+ } >+ >+ if (err != -EMSGSIZE) >+ return err; >+ return msg->len; >+} >+ > struct genl_family devlink_nl_family __ro_after_init = { > .name = DEVLINK_GENL_NAME, > .version = DEVLINK_GENL_VERSION, >-- >2.38.1 >
On 12/14/2022 6:01 PM, Jakub Kicinski wrote: > Most dumpit implementations walk the devlink instances. > This requires careful lock taking and reference dropping. > Factor the loop out and provide just a callback to handle > a single instance dump. > > Convert one user as an example, other users converted > in the next change. > > Slightly inspired by ethtool netlink code. > This is much nicer! A lot easier to read the dump for one instance than to try and parse out the iterating over each devlink.
On 12/15/2022 1:11 AM, Jiri Pirko wrote: >> >> +static const struct devlink_gen_cmd *devl_gen_cmds[] = { >> + [DEVLINK_CMD_RATE_GET] = &devl_gen_rate_get, >> +}; > > Instead of having this extra list of ops struct, woudn't it make sence > to rather implement this dumpit_one infra directly as a part of generic > netlink code? Something like: > > { > .cmd = DEVLINK_CMD_RATE_GET, > .doit = devlink_nl_cmd_rate_get_doit, > .dumpit_one = devlink_nl_cmd_rate_get_dumpit_one, > .dumpit_one_walk = devlink_nl_dumpit_one_walk, > .internal_flags = DEVLINK_NL_FLAG_NEED_RATE, > /* can be retrieved by unprivileged users */ > }, > > Where devlink_nl_dumpit_one_walk would be basically your > devlink_instance_iter_dump(), it would get an extra arg dumpit_one > function pointer from generic netlink code to call per item: > > int devlink_nl_dumpit_one_walk(struct sk_buff *msg, struct netlink_callback *cb, > int (*dumpit_one)(struct sk_buff *msg, > struct netlink_callback *cb, > void *priv)); > { > const struct genl_dumpit_info *info = genl_dumpit_info(cb); > struct devlink_nl_dump_state *dump = devl_dump_state(cb); > struct devlink *devlink; > int err = 0; > > devlink_dump_for_each_instance_get(msg, dump, devlink) { > devl_lock(devlink); > err = dumpit_one(msg, cb, devlink); > devl_unlock(devlink); > devlink_put(devlink); > > if (err) > break; > > /* restart sub-object walk for the next instance */ > dump->idx = 0; > } > > if (err != -EMSGSIZE) > return err; > return msg->len; > } > > > > Or we can avoid .dumpit_one_walk() and just have classic .dumpit() which > would get the dumpit_one() pointer cb->dumpit_one (obtainable by > a helper doing a proper check-warn_on on null). > > I agree, if we can make this part of the generic netlink code without too much trouble that would be good.
On Thu, 15 Dec 2022 10:11:03 +0100 Jiri Pirko wrote: > Instead of having this extra list of ops struct, woudn't it make sence > to rather implement this dumpit_one infra directly as a part of generic > netlink code? I was wondering about that, but none of the ideas were sufficiently neat to implement :( There's a lot of improvements that can be done in the core, starting with making more of the info structures shared between do and dump in genl :( > Something like: > > { > .cmd = DEVLINK_CMD_RATE_GET, > .doit = devlink_nl_cmd_rate_get_doit, > .dumpit_one = devlink_nl_cmd_rate_get_dumpit_one, > .dumpit_one_walk = devlink_nl_dumpit_one_walk, > .internal_flags = DEVLINK_NL_FLAG_NEED_RATE, > /* can be retrieved by unprivileged users */ > }, Growing the struct ops (especially the one called _small_) may be a hard sale for a single user. For split ops, it's a different story, because we can possibly have a flag that changes the interpretation of the union. Maybe. I'd love to have a way of breaking down the ops so that we can factor out the filling of the message (the code that is shared between doit and dump). Just for the walk I don't think it's worth it. I went in the same direction as ethtool because if over time we arrive at a similar structure we can use that as a corner stone. All in all, I think this patch is a reasonable step forward. But definitely agree that the genl infra is still painfully basic.
Thu, Dec 15, 2022 at 08:47:06PM CET, kuba@kernel.org wrote: >On Thu, 15 Dec 2022 10:11:03 +0100 Jiri Pirko wrote: >> Instead of having this extra list of ops struct, woudn't it make sence >> to rather implement this dumpit_one infra directly as a part of generic >> netlink code? > >I was wondering about that, but none of the ideas were sufficiently >neat to implement :( There's a lot of improvements that can be done >in the core, starting with making more of the info structures shared >between do and dump in genl :( > >> Something like: >> >> { >> .cmd = DEVLINK_CMD_RATE_GET, >> .doit = devlink_nl_cmd_rate_get_doit, >> .dumpit_one = devlink_nl_cmd_rate_get_dumpit_one, >> .dumpit_one_walk = devlink_nl_dumpit_one_walk, >> .internal_flags = DEVLINK_NL_FLAG_NEED_RATE, >> /* can be retrieved by unprivileged users */ >> }, > >Growing the struct ops (especially the one called _small_) may be >a hard sale for a single user. For split ops, it's a different story, >because we can possibly have a flag that changes the interpretation >of the union. Maybe. > >I'd love to have a way of breaking down the ops so that we can factor >out the filling of the message (the code that is shared between doit >and dump). Just for the walk I don't think it's worth it. Okay, that is something I thought about as well. Let me take a stab at it. > >I went in the same direction as ethtool because if over time we arrive >at a similar structure we can use that as a corner stone. > >All in all, I think this patch is a reasonable step forward. Yeah, could be always changed... >But definitely agree that the genl infra is still painfully basic.
diff --git a/net/devlink/basic.c b/net/devlink/basic.c index c6ad8133fc23..f18d8dcf9751 100644 --- a/net/devlink/basic.c +++ b/net/devlink/basic.c @@ -1219,47 +1219,40 @@ static void devlink_rate_notify(struct devlink_rate *devlink_rate, 0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL); } -static int devlink_nl_cmd_rate_get_dumpit(struct sk_buff *msg, - struct netlink_callback *cb) +static int +devlink_nl_cmd_rate_get_dumpinst(struct sk_buff *msg, struct devlink *devlink, + struct netlink_callback *cb) { struct devlink_nl_dump_state *dump = devl_dump_state(cb); - struct devlink *devlink; + struct devlink_rate *devlink_rate; + int idx = 0; int err = 0; - devlink_dump_for_each_instance_get(msg, dump, devlink) { - struct devlink_rate *devlink_rate; - int idx = 0; - - devl_lock(devlink); - list_for_each_entry(devlink_rate, &devlink->rate_list, list) { - enum devlink_command cmd = DEVLINK_CMD_RATE_NEW; - u32 id = NETLINK_CB(cb->skb).portid; + list_for_each_entry(devlink_rate, &devlink->rate_list, list) { + enum devlink_command cmd = DEVLINK_CMD_RATE_NEW; + u32 id = NETLINK_CB(cb->skb).portid; - if (idx < dump->idx) { - idx++; - continue; - } - err = devlink_nl_rate_fill(msg, devlink_rate, cmd, id, - cb->nlh->nlmsg_seq, - NLM_F_MULTI, NULL); - if (err) { - devl_unlock(devlink); - devlink_put(devlink); - dump->idx = idx; - goto out; - } + if (idx < dump->idx) { idx++; + continue; } - devl_unlock(devlink); - devlink_put(devlink); + err = devlink_nl_rate_fill(msg, devlink_rate, cmd, id, + cb->nlh->nlmsg_seq, + NLM_F_MULTI, NULL); + if (err) { + dump->idx = idx; + break; + } + idx++; } -out: - if (err != -EMSGSIZE) - return err; - return msg->len; + return err; } +const struct devlink_gen_cmd devl_gen_rate_get = { + .dump_one = devlink_nl_cmd_rate_get_dumpinst, +}; + static int devlink_nl_cmd_rate_get_doit(struct sk_buff *skb, struct genl_info *info) { @@ -9130,7 +9123,7 @@ const struct genl_small_ops devlink_nl_ops[56] = { { .cmd = DEVLINK_CMD_RATE_GET, .doit = devlink_nl_cmd_rate_get_doit, - .dumpit = devlink_nl_cmd_rate_get_dumpit, + .dumpit = devlink_instance_iter_dump, .internal_flags = DEVLINK_NL_FLAG_NEED_RATE, /* can be retrieved by unprivileged users */ }, diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h index 5adac38454fd..e49b82dd77cd 100644 --- a/net/devlink/devl_internal.h +++ b/net/devlink/devl_internal.h @@ -122,6 +122,11 @@ struct devlink_nl_dump_state { }; }; +struct devlink_gen_cmd { + int (*dump_one)(struct sk_buff *msg, struct devlink *devlink, + struct netlink_callback *cb); +}; + /* Iterate over devlink pointers which were possible to get reference to. * devlink_put() needs to be called for each iterated devlink pointer * in loop body in order to release the reference. @@ -138,6 +143,9 @@ struct devlink *devlink_get_from_attrs(struct net *net, struct nlattr **attrs); void devlink_notify_unregister(struct devlink *devlink); void devlink_notify_register(struct devlink *devlink); +int devlink_instance_iter_dump(struct sk_buff *msg, + struct netlink_callback *cb); + static inline struct devlink_nl_dump_state * devl_dump_state(struct netlink_callback *cb) { @@ -173,6 +181,8 @@ devlink_linecard_get_from_info(struct devlink *devlink, struct genl_info *info); void devlink_linecard_put(struct devlink_linecard *linecard); /* Rates */ +extern const struct devlink_gen_cmd devl_gen_rate_get; + struct devlink_rate * devlink_rate_get_from_info(struct devlink *devlink, struct genl_info *info); struct devlink_rate * diff --git a/net/devlink/netlink.c b/net/devlink/netlink.c index ce1a7d674d14..fcf10c288480 100644 --- a/net/devlink/netlink.c +++ b/net/devlink/netlink.c @@ -5,6 +5,7 @@ */ #include <net/genetlink.h> +#include <net/sock.h> #include "devl_internal.h" @@ -177,6 +178,38 @@ static void devlink_nl_post_doit(const struct genl_split_ops *ops, devlink_put(devlink); } +static const struct devlink_gen_cmd *devl_gen_cmds[] = { + [DEVLINK_CMD_RATE_GET] = &devl_gen_rate_get, +}; + +int devlink_instance_iter_dump(struct sk_buff *msg, struct netlink_callback *cb) +{ + const struct genl_dumpit_info *info = genl_dumpit_info(cb); + struct devlink_nl_dump_state *dump = devl_dump_state(cb); + const struct devlink_gen_cmd *cmd; + struct devlink *devlink; + int err = 0; + + cmd = devl_gen_cmds[info->op.cmd]; + + devlink_dump_for_each_instance_get(msg, dump, devlink) { + devl_lock(devlink); + err = cmd->dump_one(msg, devlink, cb); + devl_unlock(devlink); + devlink_put(devlink); + + if (err) + break; + + /* restart sub-object walk for the next instance */ + dump->idx = 0; + } + + if (err != -EMSGSIZE) + return err; + return msg->len; +} + struct genl_family devlink_nl_family __ro_after_init = { .name = DEVLINK_GENL_NAME, .version = DEVLINK_GENL_VERSION,
Most dumpit implementations walk the devlink instances. This requires careful lock taking and reference dropping. Factor the loop out and provide just a callback to handle a single instance dump. Convert one user as an example, other users converted in the next change. Slightly inspired by ethtool netlink code. Signed-off-by: Jakub Kicinski <kuba@kernel.org> --- net/devlink/basic.c | 55 ++++++++++++++++--------------------- net/devlink/devl_internal.h | 10 +++++++ net/devlink/netlink.c | 33 ++++++++++++++++++++++ 3 files changed, 67 insertions(+), 31 deletions(-)