[PATCH 20/38] 9p: Convert fids IDR to XArray

[Matthew Wilcox]

From: "Matthew Wilcox (Oracle)" <wi...@infradead.org>

Locking changes to use the internal XArray spinlock instead of the
client spinlock.  Also remove all references to the IDR header file
and a dangling define of P9_ROW_MAXTAG.

Signed-off-by: Matthew Wilcox (Oracle) <wi...@infradead.org>
---
 include/net/9p/client.h |  7 ++-----
 net/9p/client.c         | 23 ++++++++---------------
 net/9p/trans_fd.c       |  1 -
 net/9p/trans_rdma.c     |  1 -
 net/9p/trans_virtio.c   |  1 -
 5 files changed, 10 insertions(+), 23 deletions(-)

diff --git a/include/net/9p/client.h b/include/net/9p/client.h
index 6fe36ca0c32e..a50f98cff203 100644
--- a/include/net/9p/client.h
+++ b/include/net/9p/client.h
@@ -12,10 +12,7 @@
 #define NET_9P_CLIENT_H
 
 #include <linux/utsname.h>
-#include <linux/idr.h>
-
-/* Number of requests per row */
-#define P9_ROW_MAXTAG 255
+#include <linux/xarray.h>
 
 /** enum p9_proto_versions - 9P protocol versions
  * @p9_proto_legacy: 9P Legacy mode, pre-9P2000.u
@@ -123,7 +120,7 @@ struct p9_client {
                } tcp;
        } trans_opts;
 
-       struct idr fids;
+       struct xarray fids;
        struct xarray reqs;
 
        char name[__NEW_UTS_LEN + 1];
diff --git a/net/9p/client.c b/net/9p/client.c
index 5c566e48f63e..ca7bd0949ebb 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -14,7 +14,6 @@
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/poll.h>
-#include <linux/idr.h>
 #include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/sched/signal.h>
@@ -898,15 +897,9 @@ static struct p9_fid *p9_fid_create(struct p9_client *clnt)
        fid->uid = current_fsuid();
        fid->clnt = clnt;
        fid->rdir = NULL;
-       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();
 
+       ret = xa_alloc_irq(&clnt->fids, &fid->fid, fid,
+                               XA_LIMIT(0, P9_NOFID - 1), GFP_KERNEL);
        if (!ret)
                return fid;
 
@@ -921,9 +914,9 @@ static void p9_fid_destroy(struct p9_fid *fid)
 
        p9_debug(P9_DEBUG_FID, "fid %d\n", fid->fid);
        clnt = fid->clnt;
-       spin_lock_irqsave(&clnt->lock, flags);
-       idr_remove(&clnt->fids, fid->fid);
-       spin_unlock_irqrestore(&clnt->lock, flags);
+       xa_lock_irqsave(&clnt->fids, flags);
+       __xa_erase(&clnt->fids, fid->fid);
+       xa_unlock_irqrestore(&clnt->fids, flags);
        kfree(fid->rdir);
        kfree(fid);
 }
@@ -1014,7 +1007,7 @@ 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);
-       idr_init(&clnt->fids);
+       xa_init_flags(&clnt->fids, XA_FLAGS_ALLOC | XA_FLAGS_LOCK_IRQ);
        xa_init_flags(&clnt->reqs, XA_FLAGS_ALLOC | XA_FLAGS_LOCK_IRQ);
 
        err = parse_opts(options, clnt);
@@ -1076,7 +1069,7 @@ EXPORT_SYMBOL(p9_client_create);
 void p9_client_destroy(struct p9_client *clnt)
 {
        struct p9_fid *fid;
-       int id;
+       unsigned long id;
 
        p9_debug(P9_DEBUG_MUX, "clnt %p\n", clnt);
 
@@ -1085,7 +1078,7 @@ void p9_client_destroy(struct p9_client *clnt)
 
        v9fs_put_trans(clnt->trans_mod);
 
-       idr_for_each_entry(&clnt->fids, fid, id) {
+       xa_for_each(&clnt->fids, id, fid) {
                pr_info("Found fid %d not clunked\n", fid->fid);
                p9_fid_destroy(fid);
        }
diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index 13cd683a658a..05fa9cb2897e 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -22,7 +22,6 @@
 #include <linux/un.h>
 #include <linux/uaccess.h>
 #include <linux/inet.h>
-#include <linux/idr.h>
 #include <linux/file.h>
 #include <linux/parser.h>
 #include <linux/slab.h>
diff --git a/net/9p/trans_rdma.c b/net/9p/trans_rdma.c
index bac8dad5dd69..935f9464da6e 100644
--- a/net/9p/trans_rdma.c
+++ b/net/9p/trans_rdma.c
@@ -23,7 +23,6 @@
 #include <linux/un.h>
 #include <linux/uaccess.h>
 #include <linux/inet.h>
-#include <linux/idr.h>
 #include <linux/file.h>
 #include <linux/parser.h>
 #include <linux/semaphore.h>
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index a3cd90a74012..947a85f87f22 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -22,7 +22,6 @@
 #include <linux/un.h>
 #include <linux/uaccess.h>
 #include <linux/inet.h>
-#include <linux/idr.h>
 #include <linux/file.h>
 #include <linux/highmem.h>
 #include <linux/slab.h>
-- 
2.23.0.rc1