From ea8eecdd11ee6becd09c095c8efa88aa7df95961 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 1 Mar 2011 01:34:21 +0000 Subject: NFSv4.1 move deviceid cache to filelayout driver No need for generic cache with only one user. Keep a simple hash of deviceids in the filelayout driver. Signed-off-by: Christoph Hellwig Acked-by: Andy Adamson Signed-off-by: Trond Myklebust --- fs/nfs/nfs4filelayoutdev.c | 106 ++++++++++++++++++++++++++++++++------------- 1 file changed, 77 insertions(+), 29 deletions(-) (limited to 'fs/nfs/nfs4filelayoutdev.c') diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c index f466fed2f466..f594ca35a996 100644 --- a/fs/nfs/nfs4filelayoutdev.c +++ b/fs/nfs/nfs4filelayoutdev.c @@ -36,6 +36,30 @@ #define NFSDBG_FACILITY NFSDBG_PNFS_LD +/* + * Device ID RCU cache. A device ID is unique per client ID and layout type. + */ +#define NFS4_FL_DEVICE_ID_HASH_BITS 5 +#define NFS4_FL_DEVICE_ID_HASH_SIZE (1 << NFS4_FL_DEVICE_ID_HASH_BITS) +#define NFS4_FL_DEVICE_ID_HASH_MASK (NFS4_FL_DEVICE_ID_HASH_SIZE - 1) + +static inline u32 +nfs4_fl_deviceid_hash(struct nfs4_deviceid *id) +{ + unsigned char *cptr = (unsigned char *)id->data; + unsigned int nbytes = NFS4_DEVICEID4_SIZE; + u32 x = 0; + + while (nbytes--) { + x *= 37; + x += *cptr++; + } + return x & NFS4_FL_DEVICE_ID_HASH_MASK; +} + +static struct hlist_head filelayout_deviceid_cache[NFS4_FL_DEVICE_ID_HASH_SIZE]; +static DEFINE_SPINLOCK(filelayout_deviceid_lock); + /* * Data server cache * @@ -183,7 +207,7 @@ nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr) struct nfs4_pnfs_ds *ds; int i; - print_deviceid(&dsaddr->deviceid.de_id); + print_deviceid(&dsaddr->deviceid); for (i = 0; i < dsaddr->ds_num; i++) { ds = dsaddr->ds_list[i]; @@ -200,15 +224,6 @@ nfs4_fl_free_deviceid(struct nfs4_file_layout_dsaddr *dsaddr) kfree(dsaddr); } -void -nfs4_fl_free_deviceid_callback(struct pnfs_deviceid_node *device) -{ - struct nfs4_file_layout_dsaddr *dsaddr = - container_of(device, struct nfs4_file_layout_dsaddr, deviceid); - - nfs4_fl_free_deviceid(dsaddr); -} - static struct nfs4_pnfs_ds * nfs4_pnfs_ds_add(struct inode *inode, u32 ip_addr, u32 port) { @@ -361,7 +376,7 @@ decode_device(struct inode *ino, struct pnfs_device *pdev) dsaddr->stripe_count = cnt; dsaddr->ds_num = num; - memcpy(&dsaddr->deviceid.de_id, &pdev->dev_id, sizeof(pdev->dev_id)); + memcpy(&dsaddr->deviceid, &pdev->dev_id, sizeof(pdev->dev_id)); /* Go back an read stripe indices */ p = indicesp; @@ -411,28 +426,37 @@ out_err: } /* - * Decode the opaque device specified in 'dev' - * and add it to the list of available devices. - * If the deviceid is already cached, nfs4_add_deviceid will return - * a pointer to the cached struct and throw away the new. + * Decode the opaque device specified in 'dev' and add it to the cache of + * available devices. */ -static struct nfs4_file_layout_dsaddr* +static struct nfs4_file_layout_dsaddr * decode_and_add_device(struct inode *inode, struct pnfs_device *dev) { - struct nfs4_file_layout_dsaddr *dsaddr; - struct pnfs_deviceid_node *d; + struct nfs4_file_layout_dsaddr *d, *new; + long hash; - dsaddr = decode_device(inode, dev); - if (!dsaddr) { + new = decode_device(inode, dev); + if (!new) { printk(KERN_WARNING "%s: Could not decode or add device\n", __func__); return NULL; } - d = pnfs_add_deviceid(NFS_SERVER(inode)->nfs_client->cl_devid_cache, - &dsaddr->deviceid); + spin_lock(&filelayout_deviceid_lock); + d = nfs4_fl_find_get_deviceid(&new->deviceid); + if (d) { + spin_unlock(&filelayout_deviceid_lock); + nfs4_fl_free_deviceid(new); + return d; + } + + INIT_HLIST_NODE(&new->node); + atomic_set(&new->ref, 1); + hash = nfs4_fl_deviceid_hash(&new->deviceid); + hlist_add_head_rcu(&new->node, &filelayout_deviceid_cache[hash]); + spin_unlock(&filelayout_deviceid_lock); - return container_of(d, struct nfs4_file_layout_dsaddr, deviceid); + return new; } /* @@ -507,14 +531,38 @@ out_free: return dsaddr; } -struct nfs4_file_layout_dsaddr * -nfs4_fl_find_get_deviceid(struct nfs_client *clp, struct nfs4_deviceid *id) +void +nfs4_fl_put_deviceid(struct nfs4_file_layout_dsaddr *dsaddr) { - struct pnfs_deviceid_node *d; + if (atomic_dec_and_lock(&dsaddr->ref, &filelayout_deviceid_lock)) { + hlist_del_rcu(&dsaddr->node); + spin_unlock(&filelayout_deviceid_lock); + + synchronize_rcu(); + nfs4_fl_free_deviceid(dsaddr); + } +} - d = pnfs_find_get_deviceid(clp->cl_devid_cache, id); - return (d == NULL) ? NULL : - container_of(d, struct nfs4_file_layout_dsaddr, deviceid); +struct nfs4_file_layout_dsaddr * +nfs4_fl_find_get_deviceid(struct nfs4_deviceid *id) +{ + struct nfs4_file_layout_dsaddr *d; + struct hlist_node *n; + long hash = nfs4_fl_deviceid_hash(id); + + + rcu_read_lock(); + hlist_for_each_entry_rcu(d, n, &filelayout_deviceid_cache[hash], node) { + if (!memcmp(&d->deviceid, id, sizeof(*id))) { + if (!atomic_inc_not_zero(&d->ref)) + goto fail; + rcu_read_unlock(); + return d; + } + } +fail: + rcu_read_unlock(); + return NULL; } /* -- cgit v1.2.3