diff options
Diffstat (limited to 'fs/nfs/direct.c')
| -rw-r--r-- | fs/nfs/direct.c | 949 |
1 files changed, 535 insertions, 414 deletions
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 4ae2f3b..0f583cb 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -7,11 +7,11 @@ * * 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 @@ -34,6 +34,7 @@ * 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 * */ @@ -54,10 +55,10 @@ #include <asm/uaccess.h> #include <asm/atomic.h> +#include "iostat.h" + #define NFSDBG_FACILITY NFSDBG_VFS -#define MAX_DIRECTIO_SIZE (4096UL << PAGE_SHIFT) -static void nfs_free_user_pages(struct page **pages, int npages, int do_dirty); static kmem_cache_t *nfs_direct_cachep; /* @@ -65,38 +66,78 @@ static kmem_cache_t *nfs_direct_cachep; */ struct nfs_direct_req { struct kref kref; /* release manager */ - struct list_head list; /* nfs_read_data structs */ - wait_queue_head_t wait; /* wait for i/o completion */ + + /* 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 */ - atomic_t complete, /* i/os we're waiting for */ - count, /* bytes actually processed */ + + /* 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) +{ + struct dentry *dentry = iocb->ki_filp->f_dentry; + + dprintk("NFS: nfs_direct_IO (%s) off/no(%Ld/%lu) EINVAL\n", + 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 type overflow */ - /* XXX: this can probably be as large as INT_MAX */ - if (size > MAX_DIRECTIO_SIZE) { - *pages = NULL; - return -EFBIG; - } - page_count = (user_addr + size + PAGE_SIZE - 1) >> PAGE_SHIFT; page_count -= user_addr >> PAGE_SHIFT; @@ -108,75 +149,117 @@ nfs_get_user_pages(int rw, unsigned long user_addr, size_t size, page_count, (rw == READ), 0, *pages, NULL); up_read(¤t->mm->mmap_sem); - /* - * 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 && result < page_count) { - nfs_free_user_pages(*pages, result, 0); + 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; - result = -EFAULT; } } return result; } -/** - * nfs_free_user_pages - tear down page struct array - * @pages: array of page struct pointers underlying target buffer - * @npages: number of pages in the array - * @do_dirty: dirty the pages as we release them - */ -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++) { - struct page *page = pages[i]; - if (do_dirty && !PageCompound(page)) - set_page_dirty_lock(page); - page_cache_release(page); - } - 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_req_release - release nfs_direct_req structure for direct read - * @kref: kref object embedded in an nfs_direct_req structure - * - */ static void nfs_direct_req_release(struct kref *kref) { struct nfs_direct_req *dreq = container_of(kref, struct nfs_direct_req, kref); + + if (dreq->ctx != NULL) + put_nfs_open_context(dreq->ctx); kmem_cache_free(nfs_direct_cachep, dreq); } -/** - * nfs_direct_read_alloc - allocate nfs_read_data structures for direct read - * @count: count of bytes for the read request - * @rsize: local rsize setting +/* + * Collects and returns the final error value/byte-count. + */ +static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq) +{ + ssize_t result = -EIOCBQUEUED; + + /* Async requests don't wait here */ + if (dreq->iocb) + goto out; + + result = wait_for_completion_interruptible(&dreq->completion); + + if (!result) + result = dreq->error; + if (!result) + result = dreq->count; + +out: + kref_put(&dreq->kref, nfs_direct_req_release); + return (ssize_t) result; +} + +/* + * 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) + res = (long) dreq->count; + aio_complete(dreq->iocb, res, 0); + } + complete_all(&dreq->completion); + + kref_put(&dreq->kref, nfs_direct_req_release); +} + +/* * 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, unsigned int rsize) +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 reads = 0; unsigned int rpages = (rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; - dreq = kmem_cache_alloc(nfs_direct_cachep, SLAB_KERNEL); + dreq = nfs_direct_req_alloc(); if (!dreq) return NULL; - kref_init(&dreq->kref); - init_waitqueue_head(&dreq->wait); - INIT_LIST_HEAD(&dreq->list); - atomic_set(&dreq->count, 0); - atomic_set(&dreq->error, 0); - list = &dreq->list; for(;;) { struct nfs_read_data *data = nfs_readdata_alloc(rpages); @@ -196,72 +279,70 @@ static struct nfs_direct_req *nfs_direct_read_alloc(size_t nbytes, unsigned int list_add(&data->pages, list); data->req = (struct nfs_page *) dreq; - reads++; + dreq->outstanding++; if (nbytes <= rsize) break; nbytes -= rsize; } kref_get(&dreq->kref); - atomic_set(&dreq->complete, reads); return dreq; } -/** - * nfs_direct_read_result - handle a read reply for a direct read request - * @data: address of NFS READ operation control block - * @status: status of this NFS READ operation - * - * 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_read_wait (for instance, if someone hits ^C on a slow server). - */ -static void nfs_direct_read_result(struct nfs_read_data *data, int status) +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 (likely(status >= 0)) - atomic_add(data->res.count, &dreq->count); + if (nfs_readpage_result(task, data) != 0) + return; + + spin_lock(&dreq->lock); + + if (likely(task->tk_status >= 0)) + dreq->count += data->res.count; else - atomic_set(&dreq->error, status); + dreq->error = task->tk_status; - if (unlikely(atomic_dec_and_test(&dreq->complete))) { - nfs_free_user_pages(dreq->pages, dreq->npages, 1); - wake_up(&dreq->wait); - kref_put(&dreq->kref, nfs_direct_req_release); + if (--dreq->outstanding) { + spin_unlock(&dreq->lock); + return; } + + spin_unlock(&dreq->lock); + nfs_direct_complete(dreq); } -/** - * nfs_direct_read_schedule - dispatch NFS READ operations for a direct read - * @dreq: address of nfs_direct_req struct for this request - * @inode: target inode - * @ctx: target file open context - * @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 - * +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 void nfs_direct_read_schedule(struct nfs_direct_req *dreq, - struct inode *inode, struct nfs_open_context *ctx, - unsigned long user_addr, size_t count, loff_t file_offset) +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 curpage, pgbase; - unsigned int rsize = NFS_SERVER(inode)->rsize; curpage = 0; - pgbase = user_addr & ~PAGE_MASK; + pgbase = dreq->user_addr & ~PAGE_MASK; do { struct nfs_read_data *data; - unsigned int bytes; + 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); @@ -269,7 +350,7 @@ static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, data->cred = ctx->cred; data->args.fh = NFS_FH(inode); data->args.context = ctx; - data->args.offset = file_offset; + data->args.offset = pos; data->args.pgbase = pgbase; data->args.pages = &pages[curpage]; data->args.count = bytes; @@ -277,77 +358,38 @@ static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, 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; - data->complete = nfs_direct_read_result; lock_kernel(); rpc_execute(&data->task); unlock_kernel(); - dfprintk(VFS, "NFS: %4d initiated direct read call (req %s/%Ld, %u bytes @ offset %Lu)\n", + 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); - file_offset += bytes; + pos += bytes; pgbase += bytes; curpage += pgbase >> PAGE_SHIFT; pgbase &= ~PAGE_MASK; count -= bytes; } while (count != 0); + BUG_ON(!list_empty(list)); } -/** - * nfs_direct_read_wait - wait for I/O completion for direct reads - * @dreq: request on which we are to wait - * @intr: whether or not this wait can be interrupted - * - * Collects and returns the final error value/byte-count. - */ -static ssize_t nfs_direct_read_wait(struct nfs_direct_req *dreq, int intr) -{ - int result = 0; - - if (intr) { - result = wait_event_interruptible(dreq->wait, - (atomic_read(&dreq->complete) == 0)); - } else { - wait_event(dreq->wait, (atomic_read(&dreq->complete) == 0)); - } - - if (!result) - result = atomic_read(&dreq->error); - if (!result) - result = atomic_read(&dreq->count); - - kref_put(&dreq->kref, nfs_direct_req_release); - return (ssize_t) result; -} - -/** - * nfs_direct_read_seg - Read in one iov segment. Generate separate - * read RPCs for each "rsize" bytes. - * @inode: target inode - * @ctx: target file open context - * @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: number of pages in the array - * - */ -static ssize_t nfs_direct_read_seg(struct inode *inode, - struct nfs_open_context *ctx, unsigned long user_addr, - size_t count, loff_t file_offset, struct page **pages, - unsigned int nr_pages) +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; @@ -355,284 +397,350 @@ static ssize_t nfs_direct_read_seg(struct inode *inode, 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; + nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count); rpc_clnt_sigmask(clnt, &oldset); - nfs_direct_read_schedule(dreq, inode, ctx, user_addr, count, - file_offset); - result = nfs_direct_read_wait(dreq, clnt->cl_intr); + nfs_direct_read_schedule(dreq); + result = nfs_direct_wait(dreq); rpc_clnt_sigunmask(clnt, &oldset); return result; } -/** - * nfs_direct_read - For each iov segment, map the user's buffer - * then generate read RPCs. - * @inode: target inode - * @ctx: target file open context - * @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've already pushed out any non-direct writes so that this read - * will see them when we read from the server. - */ -static ssize_t -nfs_direct_read(struct inode *inode, struct nfs_open_context *ctx, - const struct iovec *iov, loff_t file_offset, - unsigned long nr_segs) +static void nfs_direct_free_writedata(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; - } + 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 = nfs_direct_read_seg(inode, ctx, user_addr, size, - file_offset, pages, page_count); +#if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) +static void nfs_direct_write_reschedule(struct nfs_direct_req *dreq) +{ + struct list_head *pos; - if (result <= 0) { - if (tot_bytes > 0) - break; - return result; - } - tot_bytes += result; - file_offset += result; - if (result < size) - break; + list_splice_init(&dreq->rewrite_list, &dreq->list); + list_for_each(pos, &dreq->list) + dreq->outstanding++; + dreq->count = 0; + + nfs_direct_write_schedule(dreq, FLUSH_STABLE); +} + +static void nfs_direct_commit_result(struct rpc_task *task, void *calldata) +{ + 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; } - return tot_bytes; + dprintk("NFS: %5u commit returned %d\n", task->tk_pid, task->tk_status); + nfs_direct_write_complete(dreq, data->inode); } -/** - * nfs_direct_write_seg - Write out one iov segment. Generate separate - * write RPCs for each "wsize" bytes, then commit. - * @inode: target inode - * @ctx: target file open context - * 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 ssize_t nfs_direct_write_seg(struct inode *inode, - struct nfs_open_context *ctx, unsigned long user_addr, - size_t count, loff_t file_offset, struct page **pages, - int nr_pages) +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) { - const unsigned int wsize = NFS_SERVER(inode)->wsize; - size_t request; - int curpage, need_commit; - ssize_t result, tot_bytes; - struct nfs_writeverf first_verf; - struct nfs_write_data *wdata; - - wdata = nfs_writedata_alloc(NFS_SERVER(inode)->wpages); - if (!wdata) - return -ENOMEM; + struct nfs_write_data *data = dreq->commit_data; + struct rpc_task *task = &data->task; - wdata->inode = inode; - wdata->cred = ctx->cred; - wdata->args.fh = NFS_FH(inode); - wdata->args.context = ctx; - wdata->args.stable = NFS_UNSTABLE; - if (IS_SYNC(inode) || NFS_PROTO(inode)->version == 2 || count <= wsize) - wdata->args.stable = NFS_FILE_SYNC; - wdata->res.fattr = &wdata->fattr; - wdata->res.verf = &wdata->verf; + data->inode = dreq->inode; + data->cred = dreq->ctx->cred; - 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]; + 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; - 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); + 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); - lock_kernel(); - result = NFS_PROTO(inode)->write(wdata); - unlock_kernel(); + 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; - if (result <= 0) { - if (tot_bytes > 0) - break; - goto out; - } + dprintk("NFS: %5u initiated commit call\n", task->tk_pid); - if (tot_bytes == 0) - memcpy(&first_verf.verifier, &wdata->verf.verifier, - sizeof(first_verf.verifier)); - if (wdata->verf.committed != NFS_FILE_SYNC) { - need_commit = 1; - if (memcmp(&first_verf.verifier, &wdata->verf.verifier, - sizeof(first_verf.verifier))) - goto sync_retry; - } + lock_kernel(); + rpc_execute(&data->task); + unlock_kernel(); +} - tot_bytes += result; +static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode *inode) +{ + int flags = dreq->flags; - /* in case of a short write: stop now, let the app recover */ - if (result < wdata->args.count) + 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); + } +} - wdata->args.offset += result; - wdata->args.pgbase += result; - curpage += wdata->args.pgbase >> PAGE_SHIFT; - wdata->args.pgbase &= ~PAGE_MASK; - request -= result; - } while (request != 0); +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; +} - /* - * 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 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 - lock_kernel(); - result = NFS_PROTO(inode)->commit(wdata); - unlock_kernel(); +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 (result < 0 || memcmp(&first_verf.verifier, - &wdata->verf.verifier, - sizeof(first_verf.verifier)) != 0) - goto sync_retry; + 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; } - result = tot_bytes; -out: - nfs_end_data_update(inode); - nfs_writedata_free(wdata); - return result; + nfs_alloc_commit_data(dreq); -sync_retry: - wdata->args.stable = NFS_FILE_SYNC; - goto retry; + kref_get(&dreq->kref); + return dreq; } -/** - * nfs_direct_write - For each iov segment, map the user's buffer - * then generate write and commit RPCs. - * @inode: target inode - * @ctx: target file open context - * @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 nfs_open_context *ctx, const struct iovec *iov, - loff_t file_offset, unsigned long nr_segs) +static void nfs_direct_write_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; + int status = task->tk_status; + + if (nfs_writeback_done(task, data) != 0) + return; + + spin_lock(&dreq->lock); - result = nfs_direct_write_seg(inode, ctx, user_addr, size, - file_offset, pages, page_count); - nfs_free_user_pages(pages, page_count, 0); + if (likely(status >= 0)) + dreq->count += data->res.count; + else + dreq->error = task->tk_status; - if (result <= 0) { - if (tot_bytes > 0) + 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; - return result; + 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; + } } - tot_bytes += result; - file_offset += result; - if (result < size) - break; } - return tot_bytes; + /* In case we have to resend */ + data->args.stable = NFS_FILE_SYNC; + + spin_unlock(&dreq->lock); } -/** - * 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 - * +/* + * 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 nfs_open_context *ctx; - 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; - - ctx = (struct nfs_open_context *)file->private_data; - 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, ctx, 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, ctx, 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; } @@ -640,49 +748,40 @@ nfs_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, * 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 nfs_open_context *ctx = - (struct nfs_open_context *) file->private_data; struct address_space *mapping = file->f_mapping; - struct inode *inode = mapping->host; - struct iovec iov = { - .iov_base = buf, - .iov_len = count, - }; 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) @@ -692,9 +791,16 @@ nfs_file_direct_read(struct kiocb *iocb, char __user *buf, size_t count, loff_t if (retval) goto out; - retval = nfs_direct_read(inode, ctx, &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; @@ -704,8 +810,8 @@ out: * 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 @@ -725,28 +831,19 @@ out: * 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; + int page_count; + struct page **pages; struct file *file = iocb->ki_filp; - struct nfs_open_context *ctx = - (struct nfs_open_context *) file->private_data; struct address_space *mapping = file->f_mapping; - struct inode *inode = mapping->host; - struct iovec iov = { - .iov_base = (char __user *)buf, - }; 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); - retval = -EINVAL; - if (!is_sync_kiocb(iocb)) - goto out; - retval = generic_write_checks(file, &pos, &count, 0); if (retval) goto out; @@ -757,19 +854,35 @@ nfs_file_direct_write(struct kiocb *iocb, const char __user *buf, size_t count, retval = 0; if (!count) goto out; - iov.iov_len = count, retval = -EFAULT; - if (!access_ok(VERIFY_READ, iov.iov_base, iov.iov_len)) + if (!access_ok(VERIFY_READ, buf, count)) goto out; retval = nfs_sync_mapping(mapping); if (retval) goto out; - retval = nfs_direct_write(inode, ctx, &iov, pos, 1); + 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 + * 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) iocb->ki_pos = pos + retval; @@ -777,6 +890,10 @@ 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", @@ -790,6 +907,10 @@ int nfs_init_directcache(void) 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)) |
