*
* There are important applications whose performance or correctness
* depends on uncached access to file data. Database clusters
- * (multiple copies of the same instance running on separate hosts)
+ * (multiple copies of the same instance running on separate hosts)
* implement their own cache coherency protocol that subsumes file
- * system cache protocols. Applications that process datasets
- * considerably larger than the client's memory do not always benefit
- * from a local cache. A streaming video server, for instance, has no
+ * system cache protocols. Applications that process datasets
+ * considerably larger than the client's memory do not always benefit
+ * from a local cache. A streaming video server, for instance, has no
* need to cache the contents of a file.
*
* When an application requests uncached I/O, all read and write requests
* 08 Jul 2002 Version for 2.4.19, with bug fixes --trondmy
* 08 Jun 2003 Port to 2.5 APIs --cel
* 31 Mar 2004 Handle direct I/O without VFS support --cel
+ * 15 Sep 2004 Parallel async reads --cel
+ * 04 May 2005 support O_DIRECT with aio --cel
*
*/
#include <linux/smp_lock.h>
#include <linux/file.h>
#include <linux/pagemap.h>
+#include <linux/kref.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <asm/system.h>
#include <asm/uaccess.h>
+#include <asm/atomic.h>
+
+#include "iostat.h"
#define NFSDBG_FACILITY NFSDBG_VFS
-#define VERF_SIZE (2 * sizeof(__u32))
-#define MAX_DIRECTIO_SIZE (4096UL << PAGE_SHIFT)
+static kmem_cache_t *nfs_direct_cachep;
+
+/*
+ * This represents a set of asynchronous requests that we're waiting on
+ */
+struct nfs_direct_req {
+ struct kref kref; /* release manager */
+
+ /* I/O parameters */
+ struct list_head list, /* nfs_read/write_data structs */
+ rewrite_list; /* saved nfs_write_data structs */
+ struct nfs_open_context *ctx; /* file open context info */
+ struct kiocb * iocb; /* controlling i/o request */
+ struct inode * inode; /* target file of i/o */
+ unsigned long user_addr; /* location of user's buffer */
+ size_t user_count; /* total bytes to move */
+ loff_t pos; /* starting offset in file */
+ struct page ** pages; /* pages in our buffer */
+ unsigned int npages; /* count of pages */
+
+ /* completion state */
+ spinlock_t lock; /* protect completion state */
+ int outstanding; /* i/os we're waiting for */
+ ssize_t count, /* bytes actually processed */
+ error; /* any reported error */
+ struct completion completion; /* wait for i/o completion */
+
+ /* commit state */
+ struct nfs_write_data * commit_data; /* special write_data for commits */
+ int flags;
+#define NFS_ODIRECT_DO_COMMIT (1) /* an unstable reply was received */
+#define NFS_ODIRECT_RESCHED_WRITES (2) /* write verification failed */
+ struct nfs_writeverf verf; /* unstable write verifier */
+};
+
+static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, int sync);
+static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode);
/**
- * nfs_get_user_pages - find and set up pages underlying user's buffer
- * rw: direction (read or write)
- * user_addr: starting address of this segment of user's buffer
- * count: size of this segment
- * @pages: returned array of page struct pointers underlying user's buffer
+ * nfs_direct_IO - NFS address space operation for direct I/O
+ * @rw: direction (read or write)
+ * @iocb: target I/O control block
+ * @iov: array of vectors that define I/O buffer
+ * @pos: offset in file to begin the operation
+ * @nr_segs: size of iovec array
+ *
+ * The presence of this routine in the address space ops vector means
+ * the NFS client supports direct I/O. However, we shunt off direct
+ * read and write requests before the VFS gets them, so this method
+ * should never be called.
*/
-static inline int
-nfs_get_user_pages(int rw, unsigned long user_addr, size_t size,
- struct page ***pages)
+ssize_t nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t pos, unsigned long nr_segs)
+{
+ dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n",
+ iocb->ki_filp->f_dentry->d_name.name,
+ (long long) pos, nr_segs);
+
+ return -EINVAL;
+}
+
+static void nfs_free_user_pages(struct page **pages, int npages, int do_dirty)
+{
+ int i;
+ for (i = 0; i < npages; i++) {
+ struct page *page = pages[i];
+ if (do_dirty && !PageCompound(page))
+ set_page_dirty_lock(page);
+ page_cache_release(page);
+ }
+ kfree(pages);
+}
+
+static inline int nfs_get_user_pages(int rw, unsigned long user_addr, size_t size, struct page ***pages)
{
int result = -ENOMEM;
unsigned long page_count;
size_t array_size;
- /* set an arbitrary limit to prevent arithmetic overflow */
- if (size > MAX_DIRECTIO_SIZE)
- return -EFBIG;
-
page_count = (user_addr + size + PAGE_SIZE - 1) >> PAGE_SHIFT;
page_count -= user_addr >> PAGE_SHIFT;
page_count, (rw == READ), 0,
*pages, NULL);
up_read(¤t->mm->mmap_sem);
+ if (result != page_count) {
+ /*
+ * If we got fewer pages than expected from
+ * get_user_pages(), the user buffer runs off the
+ * end of a mapping; return EFAULT.
+ */
+ if (result >= 0) {
+ nfs_free_user_pages(*pages, result, 0);
+ result = -EFAULT;
+ } else
+ kfree(*pages);
+ *pages = NULL;
+ }
}
return result;
}
-/**
- * nfs_free_user_pages - tear down page struct array
- * @pages: array of page struct pointers underlying target buffer
- */
-static void
-nfs_free_user_pages(struct page **pages, int npages, int do_dirty)
+static inline struct nfs_direct_req *nfs_direct_req_alloc(void)
{
- int i;
- for (i = 0; i < npages; i++) {
- if (do_dirty)
- set_page_dirty_lock(pages[i]);
- page_cache_release(pages[i]);
- }
- kfree(pages);
+ struct nfs_direct_req *dreq;
+
+ dreq = kmem_cache_alloc(nfs_direct_cachep, SLAB_KERNEL);
+ if (!dreq)
+ return NULL;
+
+ kref_init(&dreq->kref);
+ init_completion(&dreq->completion);
+ INIT_LIST_HEAD(&dreq->list);
+ INIT_LIST_HEAD(&dreq->rewrite_list);
+ dreq->iocb = NULL;
+ dreq->ctx = NULL;
+ spin_lock_init(&dreq->lock);
+ dreq->outstanding = 0;
+ dreq->count = 0;
+ dreq->error = 0;
+ dreq->flags = 0;
+
+ return dreq;
}
-/**
- * nfs_direct_read_seg - Read in one iov segment. Generate separate
- * read RPCs for each "rsize" bytes.
- * @inode: target inode
- * @file: target file (may be NULL)
- * user_addr: starting address of this segment of user's buffer
- * count: size of this segment
- * file_offset: offset in file to begin the operation
- * @pages: array of addresses of page structs defining user's buffer
- * nr_pages: size of pages array
- */
-static int
-nfs_direct_read_seg(struct inode *inode, struct file *file,
- unsigned long user_addr, size_t count, loff_t file_offset,
- struct page **pages, int nr_pages)
+static void nfs_direct_req_release(struct kref *kref)
{
- const unsigned int rsize = NFS_SERVER(inode)->rsize;
- int tot_bytes = 0;
- int curpage = 0;
- struct nfs_read_data rdata = {
- .inode = inode,
- .args = {
- .fh = NFS_FH(inode),
- .lockowner = current->files,
- },
- .res = {
- .fattr = &rdata.fattr,
- },
- };
-
- rdata.args.pgbase = user_addr & ~PAGE_MASK;
- rdata.args.offset = file_offset;
- do {
- int result;
-
- rdata.args.count = count;
- if (rdata.args.count > rsize)
- rdata.args.count = rsize;
- rdata.args.pages = &pages[curpage];
-
- dprintk("NFS: direct read: c=%u o=%Ld ua=%lu, pb=%u, cp=%u\n",
- rdata.args.count, (long long) rdata.args.offset,
- user_addr + tot_bytes, rdata.args.pgbase, curpage);
+ struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref);
- lock_kernel();
- result = NFS_PROTO(inode)->read(&rdata, file);
- unlock_kernel();
+ if (dreq->ctx != NULL)
+ put_nfs_open_context(dreq->ctx);
+ kmem_cache_free(nfs_direct_cachep, dreq);
+}
- if (result <= 0) {
- if (tot_bytes > 0)
- break;
- if (result == -EISDIR)
- result = -EINVAL;
- return result;
- }
+/*
+ * Collects and returns the final error value/byte-count.
+ */
+static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq)
+{
+ ssize_t result = -EIOCBQUEUED;
- tot_bytes += result;
- if (rdata.res.eof)
- break;
+ /* Async requests don't wait here */
+ if (dreq->iocb)
+ goto out;
- rdata.args.offset += result;
- rdata.args.pgbase += result;
- curpage += rdata.args.pgbase >> PAGE_SHIFT;
- rdata.args.pgbase &= ~PAGE_MASK;
- count -= result;
- } while (count != 0);
+ result = wait_for_completion_interruptible(&dreq->completion);
- /* XXX: should we zero the rest of the user's buffer if we
- * hit eof? */
+ if (!result)
+ result = dreq->error;
+ if (!result)
+ result = dreq->count;
- return tot_bytes;
+out:
+ kref_put(&dreq->kref, nfs_direct_req_release);
+ return (ssize_t) result;
}
-/**
- * nfs_direct_read - For each iov segment, map the user's buffer
- * then generate read RPCs.
- * @inode: target inode
- * @file: target file (may be NULL)
- * @iov: array of vectors that define I/O buffer
- * file_offset: offset in file to begin the operation
- * nr_segs: size of iovec array
+/*
+ * We must hold a reference to all the pages in this direct read request
+ * until the RPCs complete. This could be long *after* we are woken up in
+ * nfs_direct_wait (for instance, if someone hits ^C on a slow server).
*
- * generic_file_direct_IO has already pushed out any non-direct
- * writes so that this read will see them when we read from the
- * server.
+ * In addition, synchronous I/O uses a stack-allocated iocb. Thus we
+ * can't trust the iocb is still valid here if this is a synchronous
+ * request. If the waiter is woken prematurely, the iocb is long gone.
*/
-static ssize_t
-nfs_direct_read(struct inode *inode, struct file *file,
- const struct iovec *iov, loff_t file_offset,
- unsigned long nr_segs)
+static void nfs_direct_complete(struct nfs_direct_req *dreq)
{
- ssize_t tot_bytes = 0;
- unsigned long seg = 0;
-
- while ((seg < nr_segs) && (tot_bytes >= 0)) {
- ssize_t result;
- int page_count;
- struct page **pages;
- const struct iovec *vec = &iov[seg++];
- unsigned long user_addr = (unsigned long) vec->iov_base;
- size_t size = vec->iov_len;
-
- page_count = nfs_get_user_pages(READ, user_addr, size, &pages);
- if (page_count < 0) {
- nfs_free_user_pages(pages, 0, 0);
- if (tot_bytes > 0)
- break;
- return page_count;
- }
+ nfs_free_user_pages(dreq->pages, dreq->npages, 1);
- result = nfs_direct_read_seg(inode, file, user_addr, size,
- file_offset, pages, page_count);
+ if (dreq->iocb) {
+ long res = (long) dreq->error;
+ if (!res)
+ res = (long) dreq->count;
+ aio_complete(dreq->iocb, res, 0);
+ }
+ complete_all(&dreq->completion);
- nfs_free_user_pages(pages, page_count, 1);
+ kref_put(&dreq->kref, nfs_direct_req_release);
+}
- if (result <= 0) {
- if (tot_bytes > 0)
- break;
- return result;
+/*
+ * Note we also set the number of requests we have in the dreq when we are
+ * done. This prevents races with I/O completion so we will always wait
+ * until all requests have been dispatched and completed.
+ */
+static struct nfs_direct_req *nfs_direct_read_alloc(size_t nbytes, size_t rsize)
+{
+ struct list_head *list;
+ struct nfs_direct_req *dreq;
+ unsigned int rpages = (rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+
+ dreq = nfs_direct_req_alloc();
+ if (!dreq)
+ return NULL;
+
+ list = &dreq->list;
+ for(;;) {
+ struct nfs_read_data *data = nfs_readdata_alloc(rpages);
+
+ if (unlikely(!data)) {
+ while (!list_empty(list)) {
+ data = list_entry(list->next,
+ struct nfs_read_data, pages);
+ list_del(&data->pages);
+ nfs_readdata_free(data);
+ }
+ kref_put(&dreq->kref, nfs_direct_req_release);
+ return NULL;
}
- tot_bytes += result;
- file_offset += result;
- if (result < size)
+
+ INIT_LIST_HEAD(&data->pages);
+ list_add(&data->pages, list);
+
+ data->req = (struct nfs_page *) dreq;
+ dreq->outstanding++;
+ if (nbytes <= rsize)
break;
+ nbytes -= rsize;
}
+ kref_get(&dreq->kref);
+ return dreq;
+}
+
+static void nfs_direct_read_result(struct rpc_task *task, void *calldata)
+{
+ struct nfs_read_data *data = calldata;
+ struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req;
+
+ if (nfs_readpage_result(task, data) != 0)
+ return;
+
+ spin_lock(&dreq->lock);
+
+ if (likely(task->tk_status >= 0))
+ dreq->count += data->res.count;
+ else
+ dreq->error = task->tk_status;
- return tot_bytes;
+ if (--dreq->outstanding) {
+ spin_unlock(&dreq->lock);
+ return;
+ }
+
+ spin_unlock(&dreq->lock);
+ nfs_direct_complete(dreq);
}
-/**
- * nfs_direct_write_seg - Write out one iov segment. Generate separate
- * write RPCs for each "wsize" bytes, then commit.
- * @inode: target inode
- * @file: target file (may be NULL)
- * user_addr: starting address of this segment of user's buffer
- * count: size of this segment
- * file_offset: offset in file to begin the operation
- * @pages: array of addresses of page structs defining user's buffer
- * nr_pages: size of pages array
+static const struct rpc_call_ops nfs_read_direct_ops = {
+ .rpc_call_done = nfs_direct_read_result,
+ .rpc_release = nfs_readdata_release,
+};
+
+/*
+ * For each nfs_read_data struct that was allocated on the list, dispatch
+ * an NFS READ operation
*/
-static int
-nfs_direct_write_seg(struct inode *inode, struct file *file,
- unsigned long user_addr, size_t count, loff_t file_offset,
- struct page **pages, int nr_pages)
+static void nfs_direct_read_schedule(struct nfs_direct_req *dreq)
{
- const unsigned int wsize = NFS_SERVER(inode)->wsize;
- size_t request;
- int curpage, need_commit, result, tot_bytes;
- struct nfs_writeverf first_verf;
- struct nfs_write_data wdata = {
- .inode = inode,
- .args = {
- .fh = NFS_FH(inode),
- .lockowner = current->files,
- },
- .res = {
- .fattr = &wdata.fattr,
- .verf = &wdata.verf,
- },
- };
-
- wdata.args.stable = NFS_UNSTABLE;
- if (IS_SYNC(inode) || NFS_PROTO(inode)->version == 2 || count <= wsize)
- wdata.args.stable = NFS_FILE_SYNC;
+ struct nfs_open_context *ctx = dreq->ctx;
+ struct inode *inode = ctx->dentry->d_inode;
+ struct list_head *list = &dreq->list;
+ struct page **pages = dreq->pages;
+ size_t count = dreq->user_count;
+ loff_t pos = dreq->pos;
+ size_t rsize = NFS_SERVER(inode)->rsize;
+ unsigned int curpage, pgbase;
- nfs_begin_data_update(inode);
-retry:
- need_commit = 0;
- tot_bytes = 0;
curpage = 0;
- request = count;
- wdata.args.pgbase = user_addr & ~PAGE_MASK;
- wdata.args.offset = file_offset;
- do {
- wdata.args.count = request;
- if (wdata.args.count > wsize)
- wdata.args.count = wsize;
- wdata.args.pages = &pages[curpage];
-
- dprintk("NFS: direct write: c=%u o=%Ld ua=%lu, pb=%u, cp=%u\n",
- wdata.args.count, (long long) wdata.args.offset,
- user_addr + tot_bytes, wdata.args.pgbase, curpage);
+ pgbase = dreq->user_addr & ~PAGE_MASK;
+ do {
+ struct nfs_read_data *data;
+ size_t bytes;
+
+ bytes = rsize;
+ if (count < rsize)
+ bytes = count;
+
+ BUG_ON(list_empty(list));
+ data = list_entry(list->next, struct nfs_read_data, pages);
+ list_del_init(&data->pages);
+
+ data->inode = inode;
+ data->cred = ctx->cred;
+ data->args.fh = NFS_FH(inode);
+ data->args.context = ctx;
+ data->args.offset = pos;
+ data->args.pgbase = pgbase;
+ data->args.pages = &pages[curpage];
+ data->args.count = bytes;
+ data->res.fattr = &data->fattr;
+ data->res.eof = 0;
+ data->res.count = bytes;
+
+ rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC,
+ &nfs_read_direct_ops, data);
+ NFS_PROTO(inode)->read_setup(data);
+
+ data->task.tk_cookie = (unsigned long) inode;
lock_kernel();
- result = NFS_PROTO(inode)->write(&wdata, file);
+ rpc_execute(&data->task);
unlock_kernel();
- if (result <= 0) {
- if (tot_bytes > 0)
- break;
- goto out;
- }
+ dfprintk(VFS, "NFS: %5u initiated direct read call (req %s/%Ld, %zu bytes @ offset %Lu)\n",
+ data->task.tk_pid,
+ inode->i_sb->s_id,
+ (long long)NFS_FILEID(inode),
+ bytes,
+ (unsigned long long)data->args.offset);
- if (tot_bytes == 0)
- memcpy(&first_verf.verifier, &wdata.verf.verifier,
- VERF_SIZE);
- if (wdata.verf.committed != NFS_FILE_SYNC) {
- need_commit = 1;
- if (memcmp(&first_verf.verifier,
- &wdata.verf.verifier, VERF_SIZE))
- goto sync_retry;
- }
+ pos += bytes;
+ pgbase += bytes;
+ curpage += pgbase >> PAGE_SHIFT;
+ pgbase &= ~PAGE_MASK;
- tot_bytes += result;
- wdata.args.offset += result;
- wdata.args.pgbase += result;
- curpage += wdata.args.pgbase >> PAGE_SHIFT;
- wdata.args.pgbase &= ~PAGE_MASK;
- request -= result;
- } while (request != 0);
+ count -= bytes;
+ } while (count != 0);
+ BUG_ON(!list_empty(list));
+}
- /*
- * Commit data written so far, even in the event of an error
- */
- if (need_commit) {
- wdata.args.count = tot_bytes;
- wdata.args.offset = file_offset;
+static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos, struct page **pages, unsigned int nr_pages)
+{
+ ssize_t result;
+ sigset_t oldset;
+ struct inode *inode = iocb->ki_filp->f_mapping->host;
+ struct rpc_clnt *clnt = NFS_CLIENT(inode);
+ struct nfs_direct_req *dreq;
+
+ dreq = nfs_direct_read_alloc(count, NFS_SERVER(inode)->rsize);
+ if (!dreq)
+ return -ENOMEM;
+
+ dreq->user_addr = user_addr;
+ dreq->user_count = count;
+ dreq->pos = pos;
+ dreq->pages = pages;
+ dreq->npages = nr_pages;
+ dreq->inode = inode;
+ dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data);
+ if (!is_sync_kiocb(iocb))
+ dreq->iocb = iocb;
- lock_kernel();
- result = NFS_PROTO(inode)->commit(&wdata, file);
- unlock_kernel();
+ nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count);
+ rpc_clnt_sigmask(clnt, &oldset);
+ nfs_direct_read_schedule(dreq);
+ result = nfs_direct_wait(dreq);
+ rpc_clnt_sigunmask(clnt, &oldset);
- if (result < 0 || memcmp(&first_verf.verifier,
- &wdata.verf.verifier,
- VERF_SIZE) != 0)
- goto sync_retry;
+ return result;
+}
+
+static void nfs_direct_free_writedata(struct nfs_direct_req *dreq)
+{
+ list_splice_init(&dreq->rewrite_list, &dreq->list);
+ while (!list_empty(&dreq->list)) {
+ struct nfs_write_data *data = list_entry(dreq->list.next, struct nfs_write_data, pages);
+ list_del(&data->pages);
+ nfs_writedata_release(data);
}
- result = tot_bytes;
+}
-out:
- nfs_end_data_update_defer(inode);
+#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
+static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
+{
+ struct list_head *pos;
- return result;
+ list_splice_init(&dreq->rewrite_list, &dreq->list);
+ list_for_each(pos, &dreq->list)
+ dreq->outstanding++;
+ dreq->count = 0;
-sync_retry:
- wdata.args.stable = NFS_FILE_SYNC;
- goto retry;
+ nfs_direct_write_schedule(dreq, FLUSH_STABLE);
}
-/**
- * nfs_direct_write - For each iov segment, map the user's buffer
- * then generate write and commit RPCs.
- * @inode: target inode
- * @file: target file (may be NULL)
- * @iov: array of vectors that define I/O buffer
- * file_offset: offset in file to begin the operation
- * nr_segs: size of iovec array
- *
- * Upon return, generic_file_direct_IO invalidates any cached pages
- * that non-direct readers might access, so they will pick up these
- * writes immediately.
- */
-static ssize_t
-nfs_direct_write(struct inode *inode, struct file *file,
- const struct iovec *iov, loff_t file_offset,
- unsigned long nr_segs)
+static void nfs_direct_commit_result(struct rpc_task *task, void *calldata)
{
- ssize_t tot_bytes = 0;
- unsigned long seg = 0;
-
- while ((seg < nr_segs) && (tot_bytes >= 0)) {
- ssize_t result;
- int page_count;
- struct page **pages;
- const struct iovec *vec = &iov[seg++];
- unsigned long user_addr = (unsigned long) vec->iov_base;
- size_t size = vec->iov_len;
-
- page_count = nfs_get_user_pages(WRITE, user_addr, size, &pages);
- if (page_count < 0) {
- nfs_free_user_pages(pages, 0, 0);
- if (tot_bytes > 0)
- break;
- return page_count;
- }
+ struct nfs_write_data *data = calldata;
+ struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req;
+
+ /* Call the NFS version-specific code */
+ if (NFS_PROTO(data->inode)->commit_done(task, data) != 0)
+ return;
+ if (unlikely(task->tk_status < 0)) {
+ dreq->error = task->tk_status;
+ dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
+ }
+ if (memcmp(&dreq->verf, &data->verf, sizeof(data->verf))) {
+ dprintk("NFS: %5u commit verify failed\n", task->tk_pid);
+ dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
+ }
- result = nfs_direct_write_seg(inode, file, user_addr, size,
- file_offset, pages, page_count);
- nfs_free_user_pages(pages, page_count, 0);
+ dprintk("NFS: %5u commit returned %d\n", task->tk_pid, task->tk_status);
+ nfs_direct_write_complete(dreq, data->inode);
+}
- if (result <= 0) {
- if (tot_bytes > 0)
- break;
- return result;
+static const struct rpc_call_ops nfs_commit_direct_ops = {
+ .rpc_call_done = nfs_direct_commit_result,
+ .rpc_release = nfs_commit_release,
+};
+
+static void nfs_direct_commit_schedule(struct nfs_direct_req *dreq)
+{
+ struct nfs_write_data *data = dreq->commit_data;
+
+ data->inode = dreq->inode;
+ data->cred = dreq->ctx->cred;
+
+ data->args.fh = NFS_FH(data->inode);
+ data->args.offset = dreq->pos;
+ data->args.count = dreq->user_count;
+ data->res.count = 0;
+ data->res.fattr = &data->fattr;
+ data->res.verf = &data->verf;
+
+ rpc_init_task(&data->task, NFS_CLIENT(dreq->inode), RPC_TASK_ASYNC,
+ &nfs_commit_direct_ops, data);
+ NFS_PROTO(data->inode)->commit_setup(data, 0);
+
+ data->task.tk_priority = RPC_PRIORITY_NORMAL;
+ data->task.tk_cookie = (unsigned long)data->inode;
+ /* Note: task.tk_ops->rpc_release will free dreq->commit_data */
+ dreq->commit_data = NULL;
+
+ dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid);
+
+ lock_kernel();
+ rpc_execute(&data->task);
+ unlock_kernel();
+}
+
+static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode)
+{
+ int flags = dreq->flags;
+
+ dreq->flags = 0;
+ switch (flags) {
+ case NFS_ODIRECT_DO_COMMIT:
+ nfs_direct_commit_schedule(dreq);
+ break;
+ case NFS_ODIRECT_RESCHED_WRITES:
+ nfs_direct_write_reschedule(dreq);
+ break;
+ default:
+ nfs_end_data_update(inode);
+ if (dreq->commit_data != NULL)
+ nfs_commit_free(dreq->commit_data);
+ nfs_direct_free_writedata(dreq);
+ nfs_direct_complete(dreq);
+ }
+}
+
+static void nfs_alloc_commit_data(struct nfs_direct_req *dreq)
+{
+ dreq->commit_data = nfs_commit_alloc(0);
+ if (dreq->commit_data != NULL)
+ dreq->commit_data->req = (struct nfs_page *) dreq;
+}
+#else
+static inline void nfs_alloc_commit_data(struct nfs_direct_req *dreq)
+{
+ dreq->commit_data = NULL;
+}
+
+static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode)
+{
+ nfs_end_data_update(inode);
+ nfs_direct_free_writedata(dreq);
+ nfs_direct_complete(dreq);
+}
+#endif
+
+static struct nfs_direct_req *nfs_direct_write_alloc(size_t nbytes, size_t wsize)
+{
+ struct list_head *list;
+ struct nfs_direct_req *dreq;
+ unsigned int wpages = (wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+
+ dreq = nfs_direct_req_alloc();
+ if (!dreq)
+ return NULL;
+
+ list = &dreq->list;
+ for(;;) {
+ struct nfs_write_data *data = nfs_writedata_alloc(wpages);
+
+ if (unlikely(!data)) {
+ while (!list_empty(list)) {
+ data = list_entry(list->next,
+ struct nfs_write_data, pages);
+ list_del(&data->pages);
+ nfs_writedata_free(data);
+ }
+ kref_put(&dreq->kref, nfs_direct_req_release);
+ return NULL;
}
- tot_bytes += result;
- file_offset += result;
- if (result < size)
+
+ INIT_LIST_HEAD(&data->pages);
+ list_add(&data->pages, list);
+
+ data->req = (struct nfs_page *) dreq;
+ dreq->outstanding++;
+ if (nbytes <= wsize)
break;
+ nbytes -= wsize;
}
- return tot_bytes;
+
+ nfs_alloc_commit_data(dreq);
+
+ kref_get(&dreq->kref);
+ return dreq;
}
-/**
- * nfs_direct_IO - NFS address space operation for direct I/O
- * rw: direction (read or write)
- * @iocb: target I/O control block
- * @iov: array of vectors that define I/O buffer
- * file_offset: offset in file to begin the operation
- * nr_segs: size of iovec array
- *
+static void nfs_direct_write_result(struct rpc_task *task, void *calldata)
+{
+ struct nfs_write_data *data = calldata;
+ struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req;
+ int status = task->tk_status;
+
+ if (nfs_writeback_done(task, data) != 0)
+ return;
+
+ spin_lock(&dreq->lock);
+
+ if (likely(status >= 0))
+ dreq->count += data->res.count;
+ else
+ dreq->error = task->tk_status;
+
+ if (data->res.verf->committed != NFS_FILE_SYNC) {
+ switch (dreq->flags) {
+ case 0:
+ memcpy(&dreq->verf, &data->verf, sizeof(dreq->verf));
+ dreq->flags = NFS_ODIRECT_DO_COMMIT;
+ break;
+ case NFS_ODIRECT_DO_COMMIT:
+ if (memcmp(&dreq->verf, &data->verf, sizeof(dreq->verf))) {
+ dprintk("NFS: %5u write verify failed\n", task->tk_pid);
+ dreq->flags = NFS_ODIRECT_RESCHED_WRITES;
+ }
+ }
+ }
+ /* In case we have to resend */
+ data->args.stable = NFS_FILE_SYNC;
+
+ spin_unlock(&dreq->lock);
+}
+
+/*
+ * NB: Return the value of the first error return code. Subsequent
+ * errors after the first one are ignored.
*/
-ssize_t
-nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
- loff_t file_offset, unsigned long nr_segs)
+static void nfs_direct_write_release(void *calldata)
{
- ssize_t result = -EINVAL;
- struct file *file = iocb->ki_filp;
- struct dentry *dentry = file->f_dentry;
- struct inode *inode = dentry->d_inode;
+ struct nfs_write_data *data = calldata;
+ struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req;
- /*
- * No support for async yet
- */
- if (!is_sync_kiocb(iocb))
- return result;
-
- switch (rw) {
- case READ:
- dprintk("NFS: direct_IO(read) (%s) off/no(%Lu/%lu)\n",
- dentry->d_name.name, file_offset, nr_segs);
-
- result = nfs_direct_read(inode, file, iov,
- file_offset, nr_segs);
- break;
- case WRITE:
- dprintk("NFS: direct_IO(write) (%s) off/no(%Lu/%lu)\n",
- dentry->d_name.name, file_offset, nr_segs);
-
- result = nfs_direct_write(inode, file, iov,
- file_offset, nr_segs);
- break;
- default:
- break;
+ spin_lock(&dreq->lock);
+ if (--dreq->outstanding) {
+ spin_unlock(&dreq->lock);
+ return;
}
+ spin_unlock(&dreq->lock);
+
+ nfs_direct_write_complete(dreq, data->inode);
+}
+
+static const struct rpc_call_ops nfs_write_direct_ops = {
+ .rpc_call_done = nfs_direct_write_result,
+ .rpc_release = nfs_direct_write_release,
+};
+
+/*
+ * For each nfs_write_data struct that was allocated on the list, dispatch
+ * an NFS WRITE operation
+ */
+static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, int sync)
+{
+ struct nfs_open_context *ctx = dreq->ctx;
+ struct inode *inode = ctx->dentry->d_inode;
+ struct list_head *list = &dreq->list;
+ struct page **pages = dreq->pages;
+ size_t count = dreq->user_count;
+ loff_t pos = dreq->pos;
+ size_t wsize = NFS_SERVER(inode)->wsize;
+ unsigned int curpage, pgbase;
+
+ curpage = 0;
+ pgbase = dreq->user_addr & ~PAGE_MASK;
+ do {
+ struct nfs_write_data *data;
+ size_t bytes;
+
+ bytes = wsize;
+ if (count < wsize)
+ bytes = count;
+
+ BUG_ON(list_empty(list));
+ data = list_entry(list->next, struct nfs_write_data, pages);
+ list_move_tail(&data->pages, &dreq->rewrite_list);
+
+ data->inode = inode;
+ data->cred = ctx->cred;
+ data->args.fh = NFS_FH(inode);
+ data->args.context = ctx;
+ data->args.offset = pos;
+ data->args.pgbase = pgbase;
+ data->args.pages = &pages[curpage];
+ data->args.count = bytes;
+ data->res.fattr = &data->fattr;
+ data->res.count = bytes;
+ data->res.verf = &data->verf;
+
+ rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC,
+ &nfs_write_direct_ops, data);
+ NFS_PROTO(inode)->write_setup(data, sync);
+
+ data->task.tk_priority = RPC_PRIORITY_NORMAL;
+ data->task.tk_cookie = (unsigned long) inode;
+
+ lock_kernel();
+ rpc_execute(&data->task);
+ unlock_kernel();
+
+ dfprintk(VFS, "NFS: %5u initiated direct write call (req %s/%Ld, %zu bytes @ offset %Lu)\n",
+ data->task.tk_pid,
+ inode->i_sb->s_id,
+ (long long)NFS_FILEID(inode),
+ bytes,
+ (unsigned long long)data->args.offset);
+
+ pos += bytes;
+ pgbase += bytes;
+ curpage += pgbase >> PAGE_SHIFT;
+ pgbase &= ~PAGE_MASK;
+
+ count -= bytes;
+ } while (count != 0);
+ BUG_ON(!list_empty(list));
+}
+
+static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos, struct page **pages, int nr_pages)
+{
+ ssize_t result;
+ sigset_t oldset;
+ struct inode *inode = iocb->ki_filp->f_mapping->host;
+ struct rpc_clnt *clnt = NFS_CLIENT(inode);
+ struct nfs_direct_req *dreq;
+ size_t wsize = NFS_SERVER(inode)->wsize;
+ int sync = 0;
+
+ dreq = nfs_direct_write_alloc(count, wsize);
+ if (!dreq)
+ return -ENOMEM;
+ if (dreq->commit_data == NULL || count < wsize)
+ sync = FLUSH_STABLE;
+
+ dreq->user_addr = user_addr;
+ dreq->user_count = count;
+ dreq->pos = pos;
+ dreq->pages = pages;
+ dreq->npages = nr_pages;
+ dreq->inode = inode;
+ dreq->ctx = get_nfs_open_context((struct nfs_open_context *)iocb->ki_filp->private_data);
+ if (!is_sync_kiocb(iocb))
+ dreq->iocb = iocb;
+
+ nfs_add_stats(inode, NFSIOS_DIRECTWRITTENBYTES, count);
+
+ nfs_begin_data_update(inode);
+
+ rpc_clnt_sigmask(clnt, &oldset);
+ nfs_direct_write_schedule(dreq, sync);
+ result = nfs_direct_wait(dreq);
+ rpc_clnt_sigunmask(clnt, &oldset);
+
return result;
}
* nfs_file_direct_read - file direct read operation for NFS files
* @iocb: target I/O control block
* @buf: user's buffer into which to read data
- * count: number of bytes to read
- * pos: byte offset in file where reading starts
+ * @count: number of bytes to read
+ * @pos: byte offset in file where reading starts
*
* We use this function for direct reads instead of calling
* generic_file_aio_read() in order to avoid gfar's check to see if
* the request starts before the end of the file. For that check
* to work, we must generate a GETATTR before each direct read, and
* even then there is a window between the GETATTR and the subsequent
- * READ where the file size could change. So our preference is simply
+ * READ where the file size could change. Our preference is simply
* to do all reads the application wants, and the server will take
* care of managing the end of file boundary.
- *
+ *
* This function also eliminates unnecessarily updating the file's
* atime locally, as the NFS server sets the file's atime, and this
* client must read the updated atime from the server back into its
* cache.
*/
-ssize_t
-nfs_file_direct_read(struct kiocb *iocb, char __user *buf, size_t count, loff_t pos)
+ssize_t nfs_file_direct_read(struct kiocb *iocb, char __user *buf, size_t count, loff_t pos)
{
ssize_t retval = -EINVAL;
- loff_t *ppos = &iocb->ki_pos;
+ int page_count;
+ struct page **pages;
struct file *file = iocb->ki_filp;
- struct dentry *dentry = file->f_dentry;
struct address_space *mapping = file->f_mapping;
- struct inode *inode = mapping->host;
- struct iovec iov = {
- .iov_base = (char *)buf,
- .iov_len = count,
- };
- dprintk("nfs: direct read(%s/%s, %lu@%lu)\n",
- dentry->d_parent->d_name.name, dentry->d_name.name,
- (unsigned long) count, (unsigned long) pos);
+ dprintk("nfs: direct read(%s/%s, %lu@%Ld)\n",
+ file->f_dentry->d_parent->d_name.name,
+ file->f_dentry->d_name.name,
+ (unsigned long) count, (long long) pos);
- if (!is_sync_kiocb(iocb))
- goto out;
if (count < 0)
goto out;
retval = -EFAULT;
- if (!access_ok(VERIFY_WRITE, iov.iov_base, iov.iov_len))
+ if (!access_ok(VERIFY_WRITE, buf, count))
goto out;
retval = 0;
if (!count)
goto out;
- if (mapping->nrpages) {
- retval = filemap_fdatawrite(mapping);
- if (retval == 0)
- retval = filemap_fdatawait(mapping);
- if (retval)
- goto out;
- }
+ retval = nfs_sync_mapping(mapping);
+ if (retval)
+ goto out;
- retval = nfs_direct_read(inode, file, &iov, pos, 1);
+ retval = nfs_get_user_pages(READ, (unsigned long) buf,
+ count, &pages);
+ if (retval < 0)
+ goto out;
+ page_count = retval;
+
+ retval = nfs_direct_read(iocb, (unsigned long) buf, count, pos,
+ pages, page_count);
if (retval > 0)
- *ppos = pos + retval;
+ iocb->ki_pos = pos + retval;
out:
return retval;
* nfs_file_direct_write - file direct write operation for NFS files
* @iocb: target I/O control block
* @buf: user's buffer from which to write data
- * count: number of bytes to write
- * pos: byte offset in file where writing starts
+ * @count: number of bytes to write
+ * @pos: byte offset in file where writing starts
*
* We use this function for direct writes instead of calling
* generic_file_aio_write() in order to avoid taking the inode
* Note that O_APPEND is not supported for NFS direct writes, as there
* is no atomic O_APPEND write facility in the NFS protocol.
*/
-ssize_t
-nfs_file_direct_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos)
+ssize_t nfs_file_direct_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos)
{
- ssize_t retval = -EINVAL;
- loff_t *ppos = &iocb->ki_pos;
- unsigned long limit = current->rlim[RLIMIT_FSIZE].rlim_cur;
+ ssize_t retval;
+ int page_count;
+ struct page **pages;
struct file *file = iocb->ki_filp;
- struct dentry *dentry = file->f_dentry;
struct address_space *mapping = file->f_mapping;
- struct inode *inode = mapping->host;
- struct iovec iov = {
- .iov_base = (char __user *)buf,
- .iov_len = count,
- };
- dfprintk(VFS, "nfs: direct write(%s/%s(%ld), %lu@%lu)\n",
- dentry->d_parent->d_name.name, dentry->d_name.name,
- inode->i_ino, (unsigned long) count, (unsigned long) pos);
+ dfprintk(VFS, "nfs: direct write(%s/%s, %lu@%Ld)\n",
+ file->f_dentry->d_parent->d_name.name,
+ file->f_dentry->d_name.name,
+ (unsigned long) count, (long long) pos);
- if (!is_sync_kiocb(iocb))
+ retval = generic_write_checks(file, &pos, &count, 0);
+ if (retval)
goto out;
- if (count < 0)
+
+ retval = -EINVAL;
+ if ((ssize_t) count < 0)
goto out;
- if (pos < 0)
+ retval = 0;
+ if (!count)
goto out;
+
retval = -EFAULT;
- if (!access_ok(VERIFY_READ, iov.iov_base, iov.iov_len))
+ if (!access_ok(VERIFY_READ, buf, count))
goto out;
- if (file->f_error) {
- retval = file->f_error;
- file->f_error = 0;
- goto out;
- }
- retval = -EFBIG;
- if (limit != RLIM_INFINITY) {
- if (pos >= limit) {
- send_sig(SIGXFSZ, current, 0);
- goto out;
- }
- if (count > limit - (unsigned long) pos)
- count = limit - (unsigned long) pos;
- }
- retval = 0;
- if (!count)
+
+ retval = nfs_sync_mapping(mapping);
+ if (retval)
goto out;
- if (mapping->nrpages) {
- retval = filemap_fdatawrite(mapping);
- if (retval == 0)
- retval = filemap_fdatawait(mapping);
- if (retval)
- goto out;
- }
+ retval = nfs_get_user_pages(WRITE, (unsigned long) buf,
+ count, &pages);
+ if (retval < 0)
+ goto out;
+ page_count = retval;
+
+ retval = nfs_direct_write(iocb, (unsigned long) buf, count,
+ pos, pages, page_count);
- retval = nfs_direct_write(inode, file, &iov, pos, 1);
+ /*
+ * XXX: nfs_end_data_update() already ensures this file's
+ * cached data is subsequently invalidated. Do we really
+ * need to call invalidate_inode_pages2() again here?
+ *
+ * For aio writes, this invalidation will almost certainly
+ * occur before the writes complete. Kind of racey.
+ */
if (mapping->nrpages)
invalidate_inode_pages2(mapping);
+
if (retval > 0)
- *ppos = pos + retval;
+ iocb->ki_pos = pos + retval;
out:
return retval;
}
+
+/**
+ * nfs_init_directcache - create a slab cache for nfs_direct_req structures
+ *
+ */
+int nfs_init_directcache(void)
+{
+ nfs_direct_cachep = kmem_cache_create("nfs_direct_cache",
+ sizeof(struct nfs_direct_req),
+ 0, (SLAB_RECLAIM_ACCOUNT|
+ SLAB_MEM_SPREAD),
+ NULL, NULL);
+ if (nfs_direct_cachep == NULL)
+ return -ENOMEM;
+
+ return 0;
+}
+
+/**
+ * nfs_init_directcache - destroy the slab cache for nfs_direct_req structures
+ *
+ */
+void nfs_destroy_directcache(void)
+{
+ if (kmem_cache_destroy(nfs_direct_cachep))
+ printk(KERN_INFO "nfs_direct_cache: not all structures were freed\n");
+}
git://git.onelab.eu / linux-2.6.git / blobdiff