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Commit f28cdf04 authored by Matthew Wilcox's avatar Matthew Wilcox Committed by Dominique Martinet
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9p: Replace the fidlist with an IDR 

The p9_idpool being used to allocate the IDs uses an IDR to allocate
the IDs ... which we then keep in a doubly-linked list, rather than in
the IDR which allocated them.  We can use an IDR directly which saves
two pointers per p9_fid, and a tiny memory allocation per p9_client.

Link: http://lkml.kernel.org/r/20180711210225.19730-4-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox <willy@infradead.org>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: default avatarDominique Martinet <dominique.martinet@cea.fr>
parent b5303be2

include/net/9p/client.h

+3 −6
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#define NET_9P_CLIENT_H



#include <linux/utsname.h>

#include <linux/idr.h>



/* Number of requests per row */

#define P9_ROW_MAXTAG 255
@@ -128,8 +129,7 @@ struct p9_req_t { 
 * @proto_version: 9P protocol version to use

 * @trans_mod: module API instantiated with this client

 * @trans: tranport instance state and API

 * @fidpool: fid handle accounting for session

 * @fidlist: List of active fid handles

 * @fids: All active FID handles

 * @tagpool - transaction id accounting for session

 * @reqs - 2D array of requests

 * @max_tag - current maximum tag id allocated
@@ -169,8 +169,7 @@ struct p9_client { 
		} tcp;

	} trans_opts;



	struct p9_idpool *fidpool;

	struct list_head fidlist;

	struct idr fids;



	struct p9_idpool *tagpool;

	struct p9_req_t *reqs[P9_ROW_MAXTAG];
@@ -188,7 +187,6 @@ struct p9_client { 
 * @iounit: the server reported maximum transaction size for this file

 * @uid: the numeric uid of the local user who owns this handle

 * @rdir: readdir accounting structure (allocated on demand)

 * @flist: per-client-instance fid tracking

 * @dlist: per-dentry fid tracking

 *

 * TODO: This needs lots of explanation.
@@ -204,7 +202,6 @@ struct p9_fid { 


	void *rdir;



	struct list_head flist;

	struct hlist_node dlist;	/* list of all fids attached to a dentry */

};

net/9p/client.c

+16 −28
Original line number Diff line number Diff line
@@ -909,30 +909,29 @@ static struct p9_fid *p9_fid_create(struct p9_client *clnt) 
{

	int ret;

	struct p9_fid *fid;

	unsigned long flags;



	p9_debug(P9_DEBUG_FID, "clnt %p\n", clnt);

	fid = kmalloc(sizeof(struct p9_fid), GFP_KERNEL);

	if (!fid)

		return NULL;



	ret = p9_idpool_get(clnt->fidpool);

	if (ret < 0)

		goto error;

	fid->fid = ret;



	memset(&fid->qid, 0, sizeof(struct p9_qid));

	fid->mode = -1;

	fid->uid = current_fsuid();

	fid->clnt = clnt;

	fid->rdir = NULL;

	spin_lock_irqsave(&clnt->lock, flags);

	list_add(&fid->flist, &clnt->fidlist);

	spin_unlock_irqrestore(&clnt->lock, flags);

	fid->fid = 0;



	idr_preload(GFP_KERNEL);

	spin_lock_irq(&clnt->lock);

	ret = idr_alloc_u32(&clnt->fids, fid, &fid->fid, P9_NOFID - 1,

			    GFP_NOWAIT);

	spin_unlock_irq(&clnt->lock);

	idr_preload_end();



	if (!ret)

		return fid;



error:

	kfree(fid);

	return NULL;

}
@@ -944,9 +943,8 @@ static void p9_fid_destroy(struct p9_fid *fid) 


	p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);

	clnt = fid->clnt;

	p9_idpool_put(fid->fid, clnt->fidpool);

	spin_lock_irqsave(&clnt->lock, flags);

	list_del(&fid->flist);

	idr_remove(&clnt->fids, fid->fid);

	spin_unlock_irqrestore(&clnt->lock, flags);

	kfree(fid->rdir);

	kfree(fid);
@@ -1029,7 +1027,7 @@ struct p9_client *p9_client_create(const char *dev_name, char *options) 
	memcpy(clnt->name, client_id, strlen(client_id) + 1);



	spin_lock_init(&clnt->lock);

	INIT_LIST_HEAD(&clnt->fidlist);

	idr_init(&clnt->fids);



	err = p9_tag_init(clnt);

	if (err < 0)
@@ -1049,18 +1047,12 @@ struct p9_client *p9_client_create(const char *dev_name, char *options) 
		goto destroy_tagpool;

	}



	clnt->fidpool = p9_idpool_create();

	if (IS_ERR(clnt->fidpool)) {

		err = PTR_ERR(clnt->fidpool);

		goto put_trans;

	}



	p9_debug(P9_DEBUG_MUX, "clnt %p trans %p msize %d protocol %d\n",

		 clnt, clnt->trans_mod, clnt->msize, clnt->proto_version);



	err = clnt->trans_mod->create(clnt, dev_name, options);

	if (err)

		goto destroy_fidpool;

		goto put_trans;



	if (clnt->msize > clnt->trans_mod->maxsize)

		clnt->msize = clnt->trans_mod->maxsize;
@@ -1073,8 +1065,6 @@ struct p9_client *p9_client_create(const char *dev_name, char *options) 


close_trans:

	clnt->trans_mod->close(clnt);

destroy_fidpool:

	p9_idpool_destroy(clnt->fidpool);

put_trans:

	v9fs_put_trans(clnt->trans_mod);

destroy_tagpool:
@@ -1087,7 +1077,8 @@ EXPORT_SYMBOL(p9_client_create); 


void p9_client_destroy(struct p9_client *clnt)

{

	struct p9_fid *fid, *fidptr;

	struct p9_fid *fid;

	int id;



	p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
@@ -1096,14 +1087,11 @@ void p9_client_destroy(struct p9_client *clnt) 


	v9fs_put_trans(clnt->trans_mod);



	list_for_each_entry_safe(fid, fidptr, &clnt->fidlist, flist) {

	idr_for_each_entry(&clnt->fids, fid, id) {

		pr_info("Found fid %d not clunked\n", fid->fid);

		p9_fid_destroy(fid);

	}



	if (clnt->fidpool)

		p9_idpool_destroy(clnt->fidpool);



	p9_tag_cleanup(clnt);



	kfree(clnt);