Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
new file mode 100644
index 0000000..4f1ba72
--- /dev/null
+++ b/fs/nfs/pagelist.c
@@ -0,0 +1,309 @@
+/*
+ * linux/fs/nfs/pagelist.c
+ *
+ * A set of helper functions for managing NFS read and write requests.
+ * The main purpose of these routines is to provide support for the
+ * coalescing of several requests into a single RPC call.
+ *
+ * Copyright 2000, 2001 (c) Trond Myklebust <trond.myklebust@fys.uio.no>
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/nfs3.h>
+#include <linux/nfs4.h>
+#include <linux/nfs_page.h>
+#include <linux/nfs_fs.h>
+#include <linux/nfs_mount.h>
+
+#define NFS_PARANOIA 1
+
+static kmem_cache_t *nfs_page_cachep;
+
+static inline struct nfs_page *
+nfs_page_alloc(void)
+{
+ struct nfs_page *p;
+ p = kmem_cache_alloc(nfs_page_cachep, SLAB_KERNEL);
+ if (p) {
+ memset(p, 0, sizeof(*p));
+ INIT_LIST_HEAD(&p->wb_list);
+ }
+ return p;
+}
+
+static inline void
+nfs_page_free(struct nfs_page *p)
+{
+ kmem_cache_free(nfs_page_cachep, p);
+}
+
+/**
+ * nfs_create_request - Create an NFS read/write request.
+ * @file: file descriptor to use
+ * @inode: inode to which the request is attached
+ * @page: page to write
+ * @offset: starting offset within the page for the write
+ * @count: number of bytes to read/write
+ *
+ * The page must be locked by the caller. This makes sure we never
+ * create two different requests for the same page, and avoids
+ * a possible deadlock when we reach the hard limit on the number
+ * of dirty pages.
+ * User should ensure it is safe to sleep in this function.
+ */
+struct nfs_page *
+nfs_create_request(struct nfs_open_context *ctx, struct inode *inode,
+ struct page *page,
+ unsigned int offset, unsigned int count)
+{
+ struct nfs_server *server = NFS_SERVER(inode);
+ struct nfs_page *req;
+
+ /* Deal with hard limits. */
+ for (;;) {
+ /* try to allocate the request struct */
+ req = nfs_page_alloc();
+ if (req != NULL)
+ break;
+
+ /* Try to free up at least one request in order to stay
+ * below the hard limit
+ */
+ if (signalled() && (server->flags & NFS_MOUNT_INTR))
+ return ERR_PTR(-ERESTARTSYS);
+ yield();
+ }
+
+ /* Initialize the request struct. Initially, we assume a
+ * long write-back delay. This will be adjusted in
+ * update_nfs_request below if the region is not locked. */
+ req->wb_page = page;
+ atomic_set(&req->wb_complete, 0);
+ req->wb_index = page->index;
+ page_cache_get(page);
+ req->wb_offset = offset;
+ req->wb_pgbase = offset;
+ req->wb_bytes = count;
+ atomic_set(&req->wb_count, 1);
+ req->wb_context = get_nfs_open_context(ctx);
+
+ return req;
+}
+
+/**
+ * nfs_unlock_request - Unlock request and wake up sleepers.
+ * @req:
+ */
+void nfs_unlock_request(struct nfs_page *req)
+{
+ if (!NFS_WBACK_BUSY(req)) {
+ printk(KERN_ERR "NFS: Invalid unlock attempted\n");
+ BUG();
+ }
+ smp_mb__before_clear_bit();
+ clear_bit(PG_BUSY, &req->wb_flags);
+ smp_mb__after_clear_bit();
+ wake_up_all(&req->wb_context->waitq);
+ nfs_release_request(req);
+}
+
+/**
+ * nfs_clear_request - Free up all resources allocated to the request
+ * @req:
+ *
+ * Release page resources associated with a write request after it
+ * has completed.
+ */
+void nfs_clear_request(struct nfs_page *req)
+{
+ if (req->wb_page) {
+ page_cache_release(req->wb_page);
+ req->wb_page = NULL;
+ }
+}
+
+
+/**
+ * nfs_release_request - Release the count on an NFS read/write request
+ * @req: request to release
+ *
+ * Note: Should never be called with the spinlock held!
+ */
+void
+nfs_release_request(struct nfs_page *req)
+{
+ if (!atomic_dec_and_test(&req->wb_count))
+ return;
+
+#ifdef NFS_PARANOIA
+ BUG_ON (!list_empty(&req->wb_list));
+ BUG_ON (NFS_WBACK_BUSY(req));
+#endif
+
+ /* Release struct file or cached credential */
+ nfs_clear_request(req);
+ put_nfs_open_context(req->wb_context);
+ 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;
+}
+
+/**
+ * nfs_wait_on_request - Wait for a request to complete.
+ * @req: request to wait upon.
+ *
+ * Interruptible by signals only if mounted with intr flag.
+ * The user is responsible for holding a count on the request.
+ */
+int
+nfs_wait_on_request(struct nfs_page *req)
+{
+ struct inode *inode = req->wb_context->dentry->d_inode;
+ struct rpc_clnt *clnt = NFS_CLIENT(inode);
+
+ if (!NFS_WBACK_BUSY(req))
+ return 0;
+ return nfs_wait_event(clnt, req->wb_context->waitq, !NFS_WBACK_BUSY(req));
+}
+
+/**
+ * nfs_coalesce_requests - Split coalesced requests out from a list.
+ * @head: source list
+ * @dst: destination list
+ * @nmax: maximum number of requests to coalesce
+ *
+ * Moves a maximum of 'nmax' elements from one list to another.
+ * The elements are checked to ensure that they form a contiguous set
+ * of pages, and that the RPC credentials are the same.
+ */
+int
+nfs_coalesce_requests(struct list_head *head, struct list_head *dst,
+ unsigned int nmax)
+{
+ struct nfs_page *req = NULL;
+ unsigned int npages = 0;
+
+ while (!list_empty(head)) {
+ struct nfs_page *prev = req;
+
+ req = nfs_list_entry(head->next);
+ if (prev) {
+ if (req->wb_context->cred != prev->wb_context->cred)
+ break;
+ if (req->wb_context->lockowner != prev->wb_context->lockowner)
+ break;
+ if (req->wb_context->state != prev->wb_context->state)
+ break;
+ if (req->wb_index != (prev->wb_index + 1))
+ break;
+
+ if (req->wb_pgbase != 0)
+ break;
+ }
+ nfs_list_remove_request(req);
+ nfs_list_add_request(req, dst);
+ npages++;
+ if (req->wb_pgbase + req->wb_bytes != PAGE_CACHE_SIZE)
+ break;
+ if (npages >= nmax)
+ break;
+ }
+ return npages;
+}
+
+/**
+ * nfs_scan_list - Scan a list for matching requests
+ * @head: One of the NFS inode request lists
+ * @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_list(struct list_head *head, struct list_head *dst,
+ unsigned long idx_start, unsigned int npages)
+{
+ struct list_head *pos, *tmp;
+ struct nfs_page *req;
+ unsigned long idx_end;
+ int res;
+
+ res = 0;
+ if (npages == 0)
+ idx_end = ~0;
+ else
+ idx_end = idx_start + npages - 1;
+
+ list_for_each_safe(pos, tmp, head) {
+
+ req = nfs_list_entry(pos);
+
+ if (req->wb_index < idx_start)
+ continue;
+ if (req->wb_index > idx_end)
+ break;
+
+ if (!nfs_lock_request(req))
+ continue;
+ nfs_list_remove_request(req);
+ nfs_list_add_request(req, dst);
+ res++;
+ }
+ return res;
+}
+
+int nfs_init_nfspagecache(void)
+{
+ nfs_page_cachep = kmem_cache_create("nfs_page",
+ sizeof(struct nfs_page),
+ 0, SLAB_HWCACHE_ALIGN,
+ NULL, NULL);
+ if (nfs_page_cachep == NULL)
+ return -ENOMEM;
+
+ return 0;
+}
+
+void nfs_destroy_nfspagecache(void)
+{
+ if (kmem_cache_destroy(nfs_page_cachep))
+ printk(KERN_INFO "nfs_page: not all structures were freed\n");
+}
+