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 */
- atomic_t io_count; /* i/os we're waiting for */
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 list_head rewrite_list; /* saved nfs_write_data structs */
struct nfs_write_data * commit_data; /* special write_data for commits */
int flags;
#define NFS_ODIRECT_DO_COMMIT (1) /* an unstable reply was received */
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);
-static const struct rpc_call_ops nfs_write_direct_ops;
-
-static inline void get_dreq(struct nfs_direct_req *dreq)
-{
- atomic_inc(&dreq->io_count);
-}
-
-static inline int put_dreq(struct nfs_direct_req *dreq)
-{
- return atomic_dec_and_test(&dreq->io_count);
-}
-
-/*
- * "size" is never larger than rsize or wsize.
- */
-static inline int nfs_direct_count_pages(unsigned long user_addr, size_t size)
-{
- int page_count;
-
- page_count = (user_addr + size + PAGE_SIZE - 1) >> PAGE_SHIFT;
- page_count -= user_addr >> PAGE_SHIFT;
- BUG_ON(page_count < 0);
-
- return page_count;
-}
-
-static inline unsigned int nfs_max_pages(unsigned int size)
-{
- return (size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-}
/**
* nfs_direct_IO - NFS address space operation for direct I/O
return -EINVAL;
}
-static void nfs_direct_dirty_pages(struct page **pages, int npages)
+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 (!PageCompound(page))
+ if (do_dirty && !PageCompound(page))
set_page_dirty_lock(page);
+ page_cache_release(page);
}
+ kfree(pages);
}
-static void nfs_direct_release_pages(struct page **pages, int npages)
+static inline int nfs_get_user_pages(int rw, unsigned long user_addr, size_t size, struct page ***pages)
{
- int i;
- for (i = 0; i < npages; i++)
- page_cache_release(pages[i]);
+ int result = -ENOMEM;
+ unsigned long page_count;
+ size_t array_size;
+
+ page_count = (user_addr + size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ page_count -= user_addr >> PAGE_SHIFT;
+
+ array_size = (page_count * sizeof(struct page *));
+ *pages = kmalloc(array_size, GFP_KERNEL);
+ if (*pages) {
+ down_read(¤t->mm->mmap_sem);
+ result = get_user_pages(current, current->mm, user_addr,
+ 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;
}
static inline struct nfs_direct_req *nfs_direct_req_alloc(void)
return NULL;
kref_init(&dreq->kref);
- kref_get(&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);
- atomic_set(&dreq->io_count, 0);
+ dreq->outstanding = 0;
dreq->count = 0;
dreq->error = 0;
dreq->flags = 0;
}
/*
- * 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.
+ * 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).
+ *
+ * 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 void nfs_direct_complete(struct nfs_direct_req *dreq)
{
+ nfs_free_user_pages(dreq->pages, dreq->npages, 1);
+
if (dreq->iocb) {
long res = (long) dreq->error;
if (!res)
}
/*
- * 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).
+ * 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;
+ }
+
+ 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;
if (nfs_readpage_result(task, data) != 0)
return;
- nfs_direct_dirty_pages(data->pagevec, data->npages);
- nfs_direct_release_pages(data->pagevec, data->npages);
-
spin_lock(&dreq->lock);
if (likely(task->tk_status >= 0))
else
dreq->error = task->tk_status;
- spin_unlock(&dreq->lock);
+ if (--dreq->outstanding) {
+ spin_unlock(&dreq->lock);
+ return;
+ }
- if (put_dreq(dreq))
- nfs_direct_complete(dreq);
+ spin_unlock(&dreq->lock);
+ nfs_direct_complete(dreq);
}
static const struct rpc_call_ops nfs_read_direct_ops = {
};
/*
- * For each rsize'd chunk of the user's buffer, dispatch an NFS READ
- * operation. If nfs_readdata_alloc() or get_user_pages() fails,
- * bail and stop sending more reads. Read length accounting is
- * handled automatically by nfs_direct_read_result(). Otherwise, if
- * no requests have been sent, just return an error.
+ * For each nfs_read_data struct that was allocated on the list, dispatch
+ * an NFS READ operation
*/
-static ssize_t nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos)
+static void nfs_direct_read_schedule(struct nfs_direct_req *dreq)
{
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 rpages = nfs_max_pages(rsize);
- unsigned int pgbase;
- int result;
- ssize_t started = 0;
-
- get_dreq(dreq);
+ unsigned int curpage, pgbase;
- pgbase = user_addr & ~PAGE_MASK;
+ curpage = 0;
+ pgbase = dreq->user_addr & ~PAGE_MASK;
do {
struct nfs_read_data *data;
size_t bytes;
- result = -ENOMEM;
- data = nfs_readdata_alloc(rpages);
- if (unlikely(!data))
- break;
-
bytes = rsize;
if (count < rsize)
bytes = count;
- data->npages = nfs_direct_count_pages(user_addr, bytes);
- down_read(¤t->mm->mmap_sem);
- result = get_user_pages(current, current->mm, user_addr,
- data->npages, 1, 0, data->pagevec, NULL);
- up_read(¤t->mm->mmap_sem);
- if (unlikely(result < data->npages)) {
- if (result > 0)
- nfs_direct_release_pages(data->pagevec, result);
- nfs_readdata_release(data);
- break;
- }
-
- get_dreq(dreq);
+ BUG_ON(list_empty(list));
+ data = list_entry(list->next, struct nfs_read_data, pages);
+ list_del_init(&data->pages);
- data->req = (struct nfs_page *) dreq;
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 = data->pagevec;
+ data->args.pages = &pages[curpage];
data->args.count = bytes;
data->res.fattr = &data->fattr;
data->res.eof = 0;
bytes,
(unsigned long long)data->args.offset);
- started += bytes;
- user_addr += bytes;
pos += bytes;
pgbase += bytes;
+ curpage += pgbase >> PAGE_SHIFT;
pgbase &= ~PAGE_MASK;
count -= bytes;
} while (count != 0);
-
- if (put_dreq(dreq))
- nfs_direct_complete(dreq);
-
- if (started)
- return 0;
- return result < 0 ? (ssize_t) result : -EFAULT;
+ BUG_ON(!list_empty(list));
}
-static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos)
+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 = 0;
+ 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_req_alloc();
+ 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))
nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count);
rpc_clnt_sigmask(clnt, &oldset);
- result = nfs_direct_read_schedule(dreq, user_addr, count, pos);
- if (!result)
- result = nfs_direct_wait(dreq);
+ nfs_direct_read_schedule(dreq);
+ result = nfs_direct_wait(dreq);
rpc_clnt_sigunmask(clnt, &oldset);
return result;
static void nfs_direct_free_writedata(struct nfs_direct_req *dreq)
{
- while (!list_empty(&dreq->rewrite_list)) {
- struct nfs_write_data *data = list_entry(dreq->rewrite_list.next, struct nfs_write_data, pages);
+ 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_direct_release_pages(data->pagevec, data->npages);
nfs_writedata_release(data);
}
}
#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4)
static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq)
{
- struct inode *inode = dreq->inode;
- struct list_head *p;
- struct nfs_write_data *data;
+ struct list_head *pos;
+ list_splice_init(&dreq->rewrite_list, &dreq->list);
+ list_for_each(pos, &dreq->list)
+ dreq->outstanding++;
dreq->count = 0;
- get_dreq(dreq);
-
- list_for_each(p, &dreq->rewrite_list) {
- data = list_entry(p, struct nfs_write_data, pages);
-
- get_dreq(dreq);
-
- /*
- * Reset data->res.
- */
- nfs_fattr_init(&data->fattr);
- data->res.count = data->args.count;
- memset(&data->verf, 0, sizeof(data->verf));
-
- /*
- * Reuse data->task; data->args should not have changed
- * since the original request was sent.
- */
- rpc_init_task(&data->task, NFS_CLIENT(inode), RPC_TASK_ASYNC,
- &nfs_write_direct_ops, data);
- NFS_PROTO(inode)->write_setup(data, FLUSH_STABLE);
-
- data->task.tk_priority = RPC_PRIORITY_NORMAL;
- data->task.tk_cookie = (unsigned long) inode;
-
- /*
- * We're called via an RPC callback, so BKL is already held.
- */
- rpc_execute(&data->task);
-
- dprintk("NFS: %5u rescheduled direct write call (req %s/%Ld, %u bytes @ offset %Lu)\n",
- data->task.tk_pid,
- inode->i_sb->s_id,
- (long long)NFS_FILEID(inode),
- data->args.count,
- (unsigned long long)data->args.offset);
- }
- if (put_dreq(dreq))
- nfs_direct_write_complete(dreq, inode);
+ nfs_direct_write_schedule(dreq, FLUSH_STABLE);
}
static void nfs_direct_commit_result(struct rpc_task *task, void *calldata)
data->cred = dreq->ctx->cred;
data->args.fh = NFS_FH(data->inode);
- data->args.offset = 0;
- data->args.count = 0;
+ 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;
}
#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;
+ }
+
+ INIT_LIST_HEAD(&data->pages);
+ list_add(&data->pages, list);
+
+ data->req = (struct nfs_page *) dreq;
+ dreq->outstanding++;
+ if (nbytes <= wsize)
+ break;
+ nbytes -= wsize;
+ }
+
+ nfs_alloc_commit_data(dreq);
+
+ kref_get(&dreq->kref);
+ return dreq;
+}
+
static void nfs_direct_write_result(struct rpc_task *task, void *calldata)
{
struct nfs_write_data *data = calldata;
}
}
}
+ /* In case we have to resend */
+ data->args.stable = NFS_FILE_SYNC;
spin_unlock(&dreq->lock);
}
struct nfs_write_data *data = calldata;
struct nfs_direct_req *dreq = (struct nfs_direct_req *) data->req;
- if (put_dreq(dreq))
- nfs_direct_write_complete(dreq, data->inode);
+ 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 = {
};
/*
- * For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE
- * operation. If nfs_writedata_alloc() or get_user_pages() fails,
- * bail and stop sending more writes. Write length accounting is
- * handled automatically by nfs_direct_write_result(). Otherwise, if
- * no requests have been sent, just return an error.
+ * For each nfs_write_data struct that was allocated on the list, dispatch
+ * an NFS WRITE operation
*/
-static ssize_t nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos, int sync)
+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 wpages = nfs_max_pages(wsize);
- unsigned int pgbase;
- int result;
- ssize_t started = 0;
+ unsigned int curpage, pgbase;
- get_dreq(dreq);
-
- pgbase = user_addr & ~PAGE_MASK;
+ curpage = 0;
+ pgbase = dreq->user_addr & ~PAGE_MASK;
do {
struct nfs_write_data *data;
size_t bytes;
- result = -ENOMEM;
- data = nfs_writedata_alloc(wpages);
- if (unlikely(!data))
- break;
-
bytes = wsize;
if (count < wsize)
bytes = count;
- data->npages = nfs_direct_count_pages(user_addr, bytes);
- down_read(¤t->mm->mmap_sem);
- result = get_user_pages(current, current->mm, user_addr,
- data->npages, 0, 0, data->pagevec, NULL);
- up_read(¤t->mm->mmap_sem);
- if (unlikely(result < data->npages)) {
- if (result > 0)
- nfs_direct_release_pages(data->pagevec, result);
- nfs_writedata_release(data);
- break;
- }
-
- get_dreq(dreq);
-
+ BUG_ON(list_empty(list));
+ data = list_entry(list->next, struct nfs_write_data, pages);
list_move_tail(&data->pages, &dreq->rewrite_list);
- data->req = (struct nfs_page *) dreq;
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 = data->pagevec;
+ data->args.pages = &pages[curpage];
data->args.count = bytes;
data->res.fattr = &data->fattr;
data->res.count = bytes;
bytes,
(unsigned long long)data->args.offset);
- started += bytes;
- user_addr += bytes;
pos += bytes;
pgbase += bytes;
+ curpage += pgbase >> PAGE_SHIFT;
pgbase &= ~PAGE_MASK;
count -= bytes;
} while (count != 0);
-
- if (put_dreq(dreq))
- nfs_direct_write_complete(dreq, inode);
-
- if (started)
- return 0;
- return result < 0 ? (ssize_t) result : -EFAULT;
+ BUG_ON(!list_empty(list));
}
-static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos)
+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 = 0;
+ ssize_t result;
sigset_t oldset;
struct inode *inode = iocb->ki_filp->f_mapping->host;
struct rpc_clnt *clnt = NFS_CLIENT(inode);
size_t wsize = NFS_SERVER(inode)->wsize;
int sync = 0;
- dreq = nfs_direct_req_alloc();
+ dreq = nfs_direct_write_alloc(count, wsize);
if (!dreq)
return -ENOMEM;
- nfs_alloc_commit_data(dreq);
-
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))
nfs_begin_data_update(inode);
rpc_clnt_sigmask(clnt, &oldset);
- result = nfs_direct_write_schedule(dreq, user_addr, count, pos, sync);
- if (!result)
- result = nfs_direct_wait(dreq);
+ nfs_direct_write_schedule(dreq, sync);
+ result = nfs_direct_wait(dreq);
rpc_clnt_sigunmask(clnt, &oldset);
return result;
ssize_t nfs_file_direct_read(struct kiocb *iocb, char __user *buf, size_t count, loff_t pos)
{
ssize_t retval = -EINVAL;
+ int page_count;
+ struct page **pages;
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
if (retval)
goto out;
- retval = nfs_direct_read(iocb, (unsigned long) buf, count, pos);
+ 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)
iocb->ki_pos = pos + retval;
ssize_t nfs_file_direct_write(struct kiocb *iocb, const char __user *buf, size_t count, loff_t pos)
{
ssize_t retval;
+ int page_count;
+ struct page **pages;
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
if (retval)
goto out;
- retval = nfs_direct_write(iocb, (unsigned long) buf, count, pos);
+ 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);
/*
* XXX: nfs_end_data_update() already ensures this file's
projects / linux-2.6 / commitdiff