[PATCH] NFS: Replace nfs_page insertion sort with a radix sort
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 4f545f3..4845911 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -135,7 +135,7 @@
int flags = sync ? FLUSH_WAIT : 0;
int ret;
- ret = nfs_commit_inode(inode, 0, 0, flags);
+ ret = nfs_commit_inode(inode, flags);
if (ret < 0)
return ret;
return 0;
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 356a33b..d53857b 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -177,36 +177,6 @@
nfs_page_free(req);
}
-/**
- * nfs_list_add_request - Insert a request into a sorted list
- * @req: request
- * @head: head of list into which to insert the request.
- *
- * Note that the wb_list is sorted by page index in order to facilitate
- * coalescing of requests.
- * We use an insertion sort that is optimized for the case of appended
- * writes.
- */
-void
-nfs_list_add_request(struct nfs_page *req, struct list_head *head)
-{
- struct list_head *pos;
-
-#ifdef NFS_PARANOIA
- if (!list_empty(&req->wb_list)) {
- printk(KERN_ERR "NFS: Add to list failed!\n");
- BUG();
- }
-#endif
- list_for_each_prev(pos, head) {
- struct nfs_page *p = nfs_list_entry(pos);
- if (p->wb_index < req->wb_index)
- break;
- }
- list_add(&req->wb_list, pos);
- req->wb_list_head = head;
-}
-
static int nfs_wait_bit_interruptible(void *word)
{
int ret = 0;
@@ -291,6 +261,62 @@
return npages;
}
+#define NFS_SCAN_MAXENTRIES 16
+/**
+ * nfs_scan_lock_dirty - Scan the radix tree for dirty requests
+ * @nfsi: NFS inode
+ * @dst: Destination list
+ * @idx_start: lower bound of page->index to scan
+ * @npages: idx_start + npages sets the upper bound to scan.
+ *
+ * Moves elements from one of the inode request lists.
+ * If the number of requests is set to 0, the entire address_space
+ * starting at index idx_start, is scanned.
+ * The requests are *not* checked to ensure that they form a contiguous set.
+ * You must be holding the inode's req_lock when calling this function
+ */
+int
+nfs_scan_lock_dirty(struct nfs_inode *nfsi, struct list_head *dst,
+ unsigned long idx_start, unsigned int npages)
+{
+ struct nfs_page *pgvec[NFS_SCAN_MAXENTRIES];
+ struct nfs_page *req;
+ unsigned long idx_end;
+ int found, i;
+ int res;
+
+ res = 0;
+ if (npages == 0)
+ idx_end = ~0;
+ else
+ idx_end = idx_start + npages - 1;
+
+ for (;;) {
+ found = radix_tree_gang_lookup_tag(&nfsi->nfs_page_tree,
+ (void **)&pgvec[0], idx_start, NFS_SCAN_MAXENTRIES,
+ NFS_PAGE_TAG_DIRTY);
+ if (found <= 0)
+ break;
+ for (i = 0; i < found; i++) {
+ req = pgvec[i];
+ if (req->wb_index > idx_end)
+ goto out;
+
+ idx_start = req->wb_index + 1;
+
+ if (nfs_set_page_writeback_locked(req)) {
+ radix_tree_tag_clear(&nfsi->nfs_page_tree,
+ req->wb_index, NFS_PAGE_TAG_DIRTY);
+ nfs_list_remove_request(req);
+ nfs_list_add_request(req, dst);
+ res++;
+ }
+ }
+ }
+out:
+ return res;
+}
+
/**
* nfs_scan_list - Scan a list for matching requests
* @head: One of the NFS inode request lists
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 58a39b0..5130eda 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -352,7 +352,7 @@
if (err < 0)
goto out;
}
- err = nfs_commit_inode(inode, 0, 0, wb_priority(wbc));
+ err = nfs_commit_inode(inode, wb_priority(wbc));
if (err > 0) {
wbc->nr_to_write -= err;
err = 0;
@@ -446,6 +446,8 @@
struct nfs_inode *nfsi = NFS_I(inode);
spin_lock(&nfsi->req_lock);
+ radix_tree_tag_set(&nfsi->nfs_page_tree,
+ req->wb_index, NFS_PAGE_TAG_DIRTY);
nfs_list_add_request(req, &nfsi->dirty);
nfsi->ndirty++;
spin_unlock(&nfsi->req_lock);
@@ -537,12 +539,15 @@
nfs_scan_dirty(struct inode *inode, struct list_head *dst, unsigned long idx_start, unsigned int npages)
{
struct nfs_inode *nfsi = NFS_I(inode);
- int res;
- res = nfs_scan_list(&nfsi->dirty, dst, idx_start, npages);
- nfsi->ndirty -= res;
- sub_page_state(nr_dirty,res);
- if ((nfsi->ndirty == 0) != list_empty(&nfsi->dirty))
- printk(KERN_ERR "NFS: desynchronized value of nfs_i.ndirty.\n");
+ int res = 0;
+
+ if (nfsi->ndirty != 0) {
+ res = nfs_scan_lock_dirty(nfsi, dst, idx_start, npages);
+ nfsi->ndirty -= res;
+ sub_page_state(nr_dirty,res);
+ if ((nfsi->ndirty == 0) != list_empty(&nfsi->dirty))
+ printk(KERN_ERR "NFS: desynchronized value of nfs_i.ndirty.\n");
+ }
return res;
}
@@ -561,11 +566,14 @@
nfs_scan_commit(struct inode *inode, struct list_head *dst, unsigned long idx_start, unsigned int npages)
{
struct nfs_inode *nfsi = NFS_I(inode);
- int res;
- res = nfs_scan_list(&nfsi->commit, dst, idx_start, npages);
- nfsi->ncommit -= res;
- if ((nfsi->ncommit == 0) != list_empty(&nfsi->commit))
- printk(KERN_ERR "NFS: desynchronized value of nfs_i.ncommit.\n");
+ int res = 0;
+
+ if (nfsi->ncommit != 0) {
+ res = nfs_scan_list(&nfsi->commit, dst, idx_start, npages);
+ nfsi->ncommit -= res;
+ if ((nfsi->ncommit == 0) != list_empty(&nfsi->commit))
+ printk(KERN_ERR "NFS: desynchronized value of nfs_i.ncommit.\n");
+ }
return res;
}
#endif
@@ -1209,36 +1217,24 @@
struct nfs_write_data *data, int how)
{
struct rpc_task *task = &data->task;
- struct nfs_page *first, *last;
+ struct nfs_page *first;
struct inode *inode;
- loff_t start, end, len;
/* Set up the RPC argument and reply structs
* NB: take care not to mess about with data->commit et al. */
list_splice_init(head, &data->pages);
first = nfs_list_entry(data->pages.next);
- last = nfs_list_entry(data->pages.prev);
inode = first->wb_context->dentry->d_inode;
- /*
- * Determine the offset range of requests in the COMMIT call.
- * We rely on the fact that data->pages is an ordered list...
- */
- start = req_offset(first);
- end = req_offset(last) + last->wb_bytes;
- len = end - start;
- /* If 'len' is not a 32-bit quantity, pass '0' in the COMMIT call */
- if (end >= i_size_read(inode) || len < 0 || len > (~((u32)0) >> 1))
- len = 0;
-
data->inode = inode;
data->cred = first->wb_context->cred;
data->args.fh = NFS_FH(data->inode);
- data->args.offset = start;
- data->args.count = len;
- data->res.count = len;
+ /* Note: we always request a commit of the entire inode */
+ data->args.offset = 0;
+ data->args.count = 0;
+ data->res.count = 0;
data->res.fattr = &data->fattr;
data->res.verf = &data->verf;
@@ -1357,8 +1353,7 @@
}
#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
-int nfs_commit_inode(struct inode *inode, unsigned long idx_start,
- unsigned int npages, int how)
+int nfs_commit_inode(struct inode *inode, int how)
{
struct nfs_inode *nfsi = NFS_I(inode);
LIST_HEAD(head);
@@ -1366,15 +1361,13 @@
error = 0;
spin_lock(&nfsi->req_lock);
- res = nfs_scan_commit(inode, &head, idx_start, npages);
+ res = nfs_scan_commit(inode, &head, 0, 0);
+ spin_unlock(&nfsi->req_lock);
if (res) {
- res += nfs_scan_commit(inode, &head, 0, 0);
- spin_unlock(&nfsi->req_lock);
error = nfs_commit_list(&head, how);
- } else
- spin_unlock(&nfsi->req_lock);
- if (error < 0)
- return error;
+ if (error < 0)
+ return error;
+ }
return res;
}
#endif
@@ -1396,7 +1389,7 @@
error = nfs_flush_inode(inode, idx_start, npages, how);
#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
if (error == 0)
- error = nfs_commit_inode(inode, idx_start, npages, how);
+ error = nfs_commit_inode(inode, how);
#endif
} while (error > 0);
return error;