| /* |
| * linux/fs/nfs/write.c |
| * |
| * Write file data over NFS. |
| * |
| * Copyright (C) 1996, 1997, Olaf Kirch <okir@monad.swb.de> |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/slab.h> |
| #include <linux/mm.h> |
| #include <linux/pagemap.h> |
| #include <linux/file.h> |
| #include <linux/writeback.h> |
| #include <linux/swap.h> |
| #include <linux/migrate.h> |
| |
| #include <linux/sunrpc/clnt.h> |
| #include <linux/nfs_fs.h> |
| #include <linux/nfs_mount.h> |
| #include <linux/nfs_page.h> |
| #include <linux/backing-dev.h> |
| |
| #include <asm/uaccess.h> |
| |
| #include "delegation.h" |
| #include "internal.h" |
| #include "iostat.h" |
| #include "nfs4_fs.h" |
| #include "fscache.h" |
| #include "pnfs.h" |
| |
| #define NFSDBG_FACILITY NFSDBG_PAGECACHE |
| |
| #define MIN_POOL_WRITE (32) |
| #define MIN_POOL_COMMIT (4) |
| |
| /* |
| * Local function declarations |
| */ |
| static void nfs_pageio_init_write(struct nfs_pageio_descriptor *desc, |
| struct inode *inode, int ioflags); |
| static void nfs_redirty_request(struct nfs_page *req); |
| static const struct rpc_call_ops nfs_write_partial_ops; |
| static const struct rpc_call_ops nfs_write_full_ops; |
| static const struct rpc_call_ops nfs_commit_ops; |
| |
| static struct kmem_cache *nfs_wdata_cachep; |
| static mempool_t *nfs_wdata_mempool; |
| static mempool_t *nfs_commit_mempool; |
| |
| struct nfs_write_data *nfs_commitdata_alloc(void) |
| { |
| struct nfs_write_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOFS); |
| |
| if (p) { |
| memset(p, 0, sizeof(*p)); |
| INIT_LIST_HEAD(&p->pages); |
| } |
| return p; |
| } |
| |
| void nfs_commit_free(struct nfs_write_data *p) |
| { |
| if (p && (p->pagevec != &p->page_array[0])) |
| kfree(p->pagevec); |
| mempool_free(p, nfs_commit_mempool); |
| } |
| |
| struct nfs_write_data *nfs_writedata_alloc(unsigned int pagecount) |
| { |
| struct nfs_write_data *p = mempool_alloc(nfs_wdata_mempool, GFP_NOFS); |
| |
| if (p) { |
| memset(p, 0, sizeof(*p)); |
| INIT_LIST_HEAD(&p->pages); |
| p->npages = pagecount; |
| if (pagecount <= ARRAY_SIZE(p->page_array)) |
| p->pagevec = p->page_array; |
| else { |
| p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOFS); |
| if (!p->pagevec) { |
| mempool_free(p, nfs_wdata_mempool); |
| p = NULL; |
| } |
| } |
| } |
| return p; |
| } |
| |
| void nfs_writedata_free(struct nfs_write_data *p) |
| { |
| if (p && (p->pagevec != &p->page_array[0])) |
| kfree(p->pagevec); |
| mempool_free(p, nfs_wdata_mempool); |
| } |
| |
| static void nfs_writedata_release(struct nfs_write_data *wdata) |
| { |
| put_lseg(wdata->lseg); |
| put_nfs_open_context(wdata->args.context); |
| nfs_writedata_free(wdata); |
| } |
| |
| static void nfs_context_set_write_error(struct nfs_open_context *ctx, int error) |
| { |
| ctx->error = error; |
| smp_wmb(); |
| set_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags); |
| } |
| |
| static struct nfs_page *nfs_page_find_request_locked(struct page *page) |
| { |
| struct nfs_page *req = NULL; |
| |
| if (PagePrivate(page)) { |
| req = (struct nfs_page *)page_private(page); |
| if (req != NULL) |
| kref_get(&req->wb_kref); |
| } |
| return req; |
| } |
| |
| static struct nfs_page *nfs_page_find_request(struct page *page) |
| { |
| struct inode *inode = page->mapping->host; |
| struct nfs_page *req = NULL; |
| |
| spin_lock(&inode->i_lock); |
| req = nfs_page_find_request_locked(page); |
| spin_unlock(&inode->i_lock); |
| return req; |
| } |
| |
| /* Adjust the file length if we're writing beyond the end */ |
| static void nfs_grow_file(struct page *page, unsigned int offset, unsigned int count) |
| { |
| struct inode *inode = page->mapping->host; |
| loff_t end, i_size; |
| pgoff_t end_index; |
| |
| spin_lock(&inode->i_lock); |
| i_size = i_size_read(inode); |
| end_index = (i_size - 1) >> PAGE_CACHE_SHIFT; |
| if (i_size > 0 && page->index < end_index) |
| goto out; |
| end = ((loff_t)page->index << PAGE_CACHE_SHIFT) + ((loff_t)offset+count); |
| if (i_size >= end) |
| goto out; |
| i_size_write(inode, end); |
| nfs_inc_stats(inode, NFSIOS_EXTENDWRITE); |
| out: |
| spin_unlock(&inode->i_lock); |
| } |
| |
| /* A writeback failed: mark the page as bad, and invalidate the page cache */ |
| static void nfs_set_pageerror(struct page *page) |
| { |
| SetPageError(page); |
| nfs_zap_mapping(page->mapping->host, page->mapping); |
| } |
| |
| /* We can set the PG_uptodate flag if we see that a write request |
| * covers the full page. |
| */ |
| static void nfs_mark_uptodate(struct page *page, unsigned int base, unsigned int count) |
| { |
| if (PageUptodate(page)) |
| return; |
| if (base != 0) |
| return; |
| if (count != nfs_page_length(page)) |
| return; |
| SetPageUptodate(page); |
| } |
| |
| static int wb_priority(struct writeback_control *wbc) |
| { |
| if (wbc->for_reclaim) |
| return FLUSH_HIGHPRI | FLUSH_STABLE; |
| if (wbc->for_kupdate || wbc->for_background) |
| return FLUSH_LOWPRI; |
| return 0; |
| } |
| |
| /* |
| * NFS congestion control |
| */ |
| |
| int nfs_congestion_kb; |
| |
| #define NFS_CONGESTION_ON_THRESH (nfs_congestion_kb >> (PAGE_SHIFT-10)) |
| #define NFS_CONGESTION_OFF_THRESH \ |
| (NFS_CONGESTION_ON_THRESH - (NFS_CONGESTION_ON_THRESH >> 2)) |
| |
| static int nfs_set_page_writeback(struct page *page) |
| { |
| int ret = test_set_page_writeback(page); |
| |
| if (!ret) { |
| struct inode *inode = page->mapping->host; |
| struct nfs_server *nfss = NFS_SERVER(inode); |
| |
| page_cache_get(page); |
| if (atomic_long_inc_return(&nfss->writeback) > |
| NFS_CONGESTION_ON_THRESH) { |
| set_bdi_congested(&nfss->backing_dev_info, |
| BLK_RW_ASYNC); |
| } |
| } |
| return ret; |
| } |
| |
| static void nfs_end_page_writeback(struct page *page) |
| { |
| struct inode *inode = page->mapping->host; |
| struct nfs_server *nfss = NFS_SERVER(inode); |
| |
| end_page_writeback(page); |
| page_cache_release(page); |
| if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) |
| clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC); |
| } |
| |
| static struct nfs_page *nfs_find_and_lock_request(struct page *page, bool nonblock) |
| { |
| struct inode *inode = page->mapping->host; |
| struct nfs_page *req; |
| int ret; |
| |
| spin_lock(&inode->i_lock); |
| for (;;) { |
| req = nfs_page_find_request_locked(page); |
| if (req == NULL) |
| break; |
| if (nfs_set_page_tag_locked(req)) |
| break; |
| /* Note: If we hold the page lock, as is the case in nfs_writepage, |
| * then the call to nfs_set_page_tag_locked() will always |
| * succeed provided that someone hasn't already marked the |
| * request as dirty (in which case we don't care). |
| */ |
| spin_unlock(&inode->i_lock); |
| if (!nonblock) |
| ret = nfs_wait_on_request(req); |
| else |
| ret = -EAGAIN; |
| nfs_release_request(req); |
| if (ret != 0) |
| return ERR_PTR(ret); |
| spin_lock(&inode->i_lock); |
| } |
| spin_unlock(&inode->i_lock); |
| return req; |
| } |
| |
| /* |
| * Find an associated nfs write request, and prepare to flush it out |
| * May return an error if the user signalled nfs_wait_on_request(). |
| */ |
| static int nfs_page_async_flush(struct nfs_pageio_descriptor *pgio, |
| struct page *page, bool nonblock) |
| { |
| struct nfs_page *req; |
| int ret = 0; |
| |
| req = nfs_find_and_lock_request(page, nonblock); |
| if (!req) |
| goto out; |
| ret = PTR_ERR(req); |
| if (IS_ERR(req)) |
| goto out; |
| |
| ret = nfs_set_page_writeback(page); |
| BUG_ON(ret != 0); |
| BUG_ON(test_bit(PG_CLEAN, &req->wb_flags)); |
| |
| if (!nfs_pageio_add_request(pgio, req)) { |
| nfs_redirty_request(req); |
| ret = pgio->pg_error; |
| } |
| out: |
| return ret; |
| } |
| |
| static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio) |
| { |
| struct inode *inode = page->mapping->host; |
| int ret; |
| |
| nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE); |
| nfs_add_stats(inode, NFSIOS_WRITEPAGES, 1); |
| |
| nfs_pageio_cond_complete(pgio, page->index); |
| ret = nfs_page_async_flush(pgio, page, wbc->sync_mode == WB_SYNC_NONE); |
| if (ret == -EAGAIN) { |
| redirty_page_for_writepage(wbc, page); |
| ret = 0; |
| } |
| return ret; |
| } |
| |
| /* |
| * Write an mmapped page to the server. |
| */ |
| static int nfs_writepage_locked(struct page *page, struct writeback_control *wbc) |
| { |
| struct nfs_pageio_descriptor pgio; |
| int err; |
| |
| nfs_pageio_init_write(&pgio, page->mapping->host, wb_priority(wbc)); |
| err = nfs_do_writepage(page, wbc, &pgio); |
| nfs_pageio_complete(&pgio); |
| if (err < 0) |
| return err; |
| if (pgio.pg_error < 0) |
| return pgio.pg_error; |
| return 0; |
| } |
| |
| int nfs_writepage(struct page *page, struct writeback_control *wbc) |
| { |
| int ret; |
| |
| ret = nfs_writepage_locked(page, wbc); |
| unlock_page(page); |
| return ret; |
| } |
| |
| static int nfs_writepages_callback(struct page *page, struct writeback_control *wbc, void *data) |
| { |
| int ret; |
| |
| ret = nfs_do_writepage(page, wbc, data); |
| unlock_page(page); |
| return ret; |
| } |
| |
| int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc) |
| { |
| struct inode *inode = mapping->host; |
| unsigned long *bitlock = &NFS_I(inode)->flags; |
| struct nfs_pageio_descriptor pgio; |
| int err; |
| |
| /* Stop dirtying of new pages while we sync */ |
| err = wait_on_bit_lock(bitlock, NFS_INO_FLUSHING, |
| nfs_wait_bit_killable, TASK_KILLABLE); |
| if (err) |
| goto out_err; |
| |
| nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGES); |
| |
| nfs_pageio_init_write(&pgio, inode, wb_priority(wbc)); |
| err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio); |
| nfs_pageio_complete(&pgio); |
| |
| clear_bit_unlock(NFS_INO_FLUSHING, bitlock); |
| smp_mb__after_clear_bit(); |
| wake_up_bit(bitlock, NFS_INO_FLUSHING); |
| |
| if (err < 0) |
| goto out_err; |
| err = pgio.pg_error; |
| if (err < 0) |
| goto out_err; |
| return 0; |
| out_err: |
| return err; |
| } |
| |
| /* |
| * Insert a write request into an inode |
| */ |
| static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req) |
| { |
| struct nfs_inode *nfsi = NFS_I(inode); |
| int error; |
| |
| error = radix_tree_preload(GFP_NOFS); |
| if (error != 0) |
| goto out; |
| |
| /* Lock the request! */ |
| nfs_lock_request_dontget(req); |
| |
| spin_lock(&inode->i_lock); |
| error = radix_tree_insert(&nfsi->nfs_page_tree, req->wb_index, req); |
| BUG_ON(error); |
| if (!nfsi->npages) { |
| igrab(inode); |
| if (nfs_have_delegation(inode, FMODE_WRITE)) |
| nfsi->change_attr++; |
| } |
| set_bit(PG_MAPPED, &req->wb_flags); |
| SetPagePrivate(req->wb_page); |
| set_page_private(req->wb_page, (unsigned long)req); |
| nfsi->npages++; |
| kref_get(&req->wb_kref); |
| radix_tree_tag_set(&nfsi->nfs_page_tree, req->wb_index, |
| NFS_PAGE_TAG_LOCKED); |
| spin_unlock(&inode->i_lock); |
| radix_tree_preload_end(); |
| out: |
| return error; |
| } |
| |
| /* |
| * Remove a write request from an inode |
| */ |
| static void nfs_inode_remove_request(struct nfs_page *req) |
| { |
| struct inode *inode = req->wb_context->path.dentry->d_inode; |
| struct nfs_inode *nfsi = NFS_I(inode); |
| |
| BUG_ON (!NFS_WBACK_BUSY(req)); |
| |
| spin_lock(&inode->i_lock); |
| set_page_private(req->wb_page, 0); |
| ClearPagePrivate(req->wb_page); |
| clear_bit(PG_MAPPED, &req->wb_flags); |
| radix_tree_delete(&nfsi->nfs_page_tree, req->wb_index); |
| nfsi->npages--; |
| if (!nfsi->npages) { |
| spin_unlock(&inode->i_lock); |
| iput(inode); |
| } else |
| spin_unlock(&inode->i_lock); |
| nfs_release_request(req); |
| } |
| |
| static void |
| nfs_mark_request_dirty(struct nfs_page *req) |
| { |
| __set_page_dirty_nobuffers(req->wb_page); |
| __mark_inode_dirty(req->wb_page->mapping->host, I_DIRTY_DATASYNC); |
| } |
| |
| #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) |
| /* |
| * Add a request to the inode's commit list. |
| */ |
| static void |
| nfs_mark_request_commit(struct nfs_page *req) |
| { |
| struct inode *inode = req->wb_context->path.dentry->d_inode; |
| struct nfs_inode *nfsi = NFS_I(inode); |
| |
| spin_lock(&inode->i_lock); |
| set_bit(PG_CLEAN, &(req)->wb_flags); |
| radix_tree_tag_set(&nfsi->nfs_page_tree, |
| req->wb_index, |
| NFS_PAGE_TAG_COMMIT); |
| nfsi->ncommit++; |
| spin_unlock(&inode->i_lock); |
| inc_zone_page_state(req->wb_page, NR_UNSTABLE_NFS); |
| inc_bdi_stat(req->wb_page->mapping->backing_dev_info, BDI_RECLAIMABLE); |
| __mark_inode_dirty(inode, I_DIRTY_DATASYNC); |
| } |
| |
| static int |
| nfs_clear_request_commit(struct nfs_page *req) |
| { |
| struct page *page = req->wb_page; |
| |
| if (test_and_clear_bit(PG_CLEAN, &(req)->wb_flags)) { |
| dec_zone_page_state(page, NR_UNSTABLE_NFS); |
| dec_bdi_stat(page->mapping->backing_dev_info, BDI_RECLAIMABLE); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static inline |
| int nfs_write_need_commit(struct nfs_write_data *data) |
| { |
| return data->verf.committed != NFS_FILE_SYNC; |
| } |
| |
| static inline |
| int nfs_reschedule_unstable_write(struct nfs_page *req) |
| { |
| if (test_and_clear_bit(PG_NEED_COMMIT, &req->wb_flags)) { |
| nfs_mark_request_commit(req); |
| return 1; |
| } |
| if (test_and_clear_bit(PG_NEED_RESCHED, &req->wb_flags)) { |
| nfs_mark_request_dirty(req); |
| return 1; |
| } |
| return 0; |
| } |
| #else |
| static inline void |
| nfs_mark_request_commit(struct nfs_page *req) |
| { |
| } |
| |
| static inline int |
| nfs_clear_request_commit(struct nfs_page *req) |
| { |
| return 0; |
| } |
| |
| static inline |
| int nfs_write_need_commit(struct nfs_write_data *data) |
| { |
| return 0; |
| } |
| |
| static inline |
| int nfs_reschedule_unstable_write(struct nfs_page *req) |
| { |
| return 0; |
| } |
| #endif |
| |
| #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) |
| static int |
| nfs_need_commit(struct nfs_inode *nfsi) |
| { |
| return radix_tree_tagged(&nfsi->nfs_page_tree, NFS_PAGE_TAG_COMMIT); |
| } |
| |
| /* |
| * nfs_scan_commit - Scan an inode for commit requests |
| * @inode: NFS inode to scan |
| * @dst: destination list |
| * @idx_start: lower bound of page->index to scan. |
| * @npages: idx_start + npages sets the upper bound to scan. |
| * |
| * Moves requests from the inode's 'commit' request list. |
| * The requests are *not* checked to ensure that they form a contiguous set. |
| */ |
| static int |
| nfs_scan_commit(struct inode *inode, struct list_head *dst, pgoff_t idx_start, unsigned int npages) |
| { |
| struct nfs_inode *nfsi = NFS_I(inode); |
| int ret; |
| |
| if (!nfs_need_commit(nfsi)) |
| return 0; |
| |
| ret = nfs_scan_list(nfsi, dst, idx_start, npages, NFS_PAGE_TAG_COMMIT); |
| if (ret > 0) |
| nfsi->ncommit -= ret; |
| if (nfs_need_commit(NFS_I(inode))) |
| __mark_inode_dirty(inode, I_DIRTY_DATASYNC); |
| return ret; |
| } |
| #else |
| static inline int nfs_need_commit(struct nfs_inode *nfsi) |
| { |
| return 0; |
| } |
| |
| static inline int nfs_scan_commit(struct inode *inode, struct list_head *dst, pgoff_t idx_start, unsigned int npages) |
| { |
| return 0; |
| } |
| #endif |
| |
| /* |
| * Search for an existing write request, and attempt to update |
| * it to reflect a new dirty region on a given page. |
| * |
| * If the attempt fails, then the existing request is flushed out |
| * to disk. |
| */ |
| static struct nfs_page *nfs_try_to_update_request(struct inode *inode, |
| struct page *page, |
| unsigned int offset, |
| unsigned int bytes) |
| { |
| struct nfs_page *req; |
| unsigned int rqend; |
| unsigned int end; |
| int error; |
| |
| if (!PagePrivate(page)) |
| return NULL; |
| |
| end = offset + bytes; |
| spin_lock(&inode->i_lock); |
| |
| for (;;) { |
| req = nfs_page_find_request_locked(page); |
| if (req == NULL) |
| goto out_unlock; |
| |
| rqend = req->wb_offset + req->wb_bytes; |
| /* |
| * Tell the caller to flush out the request if |
| * the offsets are non-contiguous. |
| * Note: nfs_flush_incompatible() will already |
| * have flushed out requests having wrong owners. |
| */ |
| if (offset > rqend |
| || end < req->wb_offset) |
| goto out_flushme; |
| |
| if (nfs_set_page_tag_locked(req)) |
| break; |
| |
| /* The request is locked, so wait and then retry */ |
| spin_unlock(&inode->i_lock); |
| error = nfs_wait_on_request(req); |
| nfs_release_request(req); |
| if (error != 0) |
| goto out_err; |
| spin_lock(&inode->i_lock); |
| } |
| |
| if (nfs_clear_request_commit(req) && |
| radix_tree_tag_clear(&NFS_I(inode)->nfs_page_tree, |
| req->wb_index, NFS_PAGE_TAG_COMMIT) != NULL) |
| NFS_I(inode)->ncommit--; |
| |
| /* Okay, the request matches. Update the region */ |
| if (offset < req->wb_offset) { |
| req->wb_offset = offset; |
| req->wb_pgbase = offset; |
| } |
| if (end > rqend) |
| req->wb_bytes = end - req->wb_offset; |
| else |
| req->wb_bytes = rqend - req->wb_offset; |
| out_unlock: |
| spin_unlock(&inode->i_lock); |
| return req; |
| out_flushme: |
| spin_unlock(&inode->i_lock); |
| nfs_release_request(req); |
| error = nfs_wb_page(inode, page); |
| out_err: |
| return ERR_PTR(error); |
| } |
| |
| /* |
| * Try to update an existing write request, or create one if there is none. |
| * |
| * Note: Should always be called with the Page Lock held to prevent races |
| * if we have to add a new request. Also assumes that the caller has |
| * already called nfs_flush_incompatible() if necessary. |
| */ |
| static struct nfs_page * nfs_setup_write_request(struct nfs_open_context* ctx, |
| struct page *page, unsigned int offset, unsigned int bytes) |
| { |
| struct inode *inode = page->mapping->host; |
| struct nfs_page *req; |
| int error; |
| |
| req = nfs_try_to_update_request(inode, page, offset, bytes); |
| if (req != NULL) |
| goto out; |
| req = nfs_create_request(ctx, inode, page, offset, bytes); |
| if (IS_ERR(req)) |
| goto out; |
| error = nfs_inode_add_request(inode, req); |
| if (error != 0) { |
| nfs_release_request(req); |
| req = ERR_PTR(error); |
| } |
| out: |
| return req; |
| } |
| |
| static int nfs_writepage_setup(struct nfs_open_context *ctx, struct page *page, |
| unsigned int offset, unsigned int count) |
| { |
| struct nfs_page *req; |
| |
| req = nfs_setup_write_request(ctx, page, offset, count); |
| if (IS_ERR(req)) |
| return PTR_ERR(req); |
| nfs_mark_request_dirty(req); |
| /* Update file length */ |
| nfs_grow_file(page, offset, count); |
| nfs_mark_uptodate(page, req->wb_pgbase, req->wb_bytes); |
| nfs_mark_request_dirty(req); |
| nfs_clear_page_tag_locked(req); |
| return 0; |
| } |
| |
| int nfs_flush_incompatible(struct file *file, struct page *page) |
| { |
| struct nfs_open_context *ctx = nfs_file_open_context(file); |
| struct nfs_page *req; |
| int do_flush, status; |
| /* |
| * Look for a request corresponding to this page. If there |
| * is one, and it belongs to another file, we flush it out |
| * before we try to copy anything into the page. Do this |
| * due to the lack of an ACCESS-type call in NFSv2. |
| * Also do the same if we find a request from an existing |
| * dropped page. |
| */ |
| do { |
| req = nfs_page_find_request(page); |
| if (req == NULL) |
| return 0; |
| do_flush = req->wb_page != page || req->wb_context != ctx || |
| req->wb_lock_context->lockowner != current->files || |
| req->wb_lock_context->pid != current->tgid; |
| nfs_release_request(req); |
| if (!do_flush) |
| return 0; |
| status = nfs_wb_page(page->mapping->host, page); |
| } while (status == 0); |
| return status; |
| } |
| |
| /* |
| * If the page cache is marked as unsafe or invalid, then we can't rely on |
| * the PageUptodate() flag. In this case, we will need to turn off |
| * write optimisations that depend on the page contents being correct. |
| */ |
| static int nfs_write_pageuptodate(struct page *page, struct inode *inode) |
| { |
| return PageUptodate(page) && |
| !(NFS_I(inode)->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_DATA)); |
| } |
| |
| /* |
| * Update and possibly write a cached page of an NFS file. |
| * |
| * XXX: Keep an eye on generic_file_read to make sure it doesn't do bad |
| * things with a page scheduled for an RPC call (e.g. invalidate it). |
| */ |
| int nfs_updatepage(struct file *file, struct page *page, |
| unsigned int offset, unsigned int count) |
| { |
| struct nfs_open_context *ctx = nfs_file_open_context(file); |
| struct inode *inode = page->mapping->host; |
| int status = 0; |
| |
| nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE); |
| |
| dprintk("NFS: nfs_updatepage(%s/%s %d@%lld)\n", |
| file->f_path.dentry->d_parent->d_name.name, |
| file->f_path.dentry->d_name.name, count, |
| (long long)(page_offset(page) + offset)); |
| |
| /* If we're not using byte range locks, and we know the page |
| * is up to date, it may be more efficient to extend the write |
| * to cover the entire page in order to avoid fragmentation |
| * inefficiencies. |
| */ |
| if (nfs_write_pageuptodate(page, inode) && |
| inode->i_flock == NULL && |
| !(file->f_flags & O_DSYNC)) { |
| count = max(count + offset, nfs_page_length(page)); |
| offset = 0; |
| } |
| |
| status = nfs_writepage_setup(ctx, page, offset, count); |
| if (status < 0) |
| nfs_set_pageerror(page); |
| |
| dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n", |
| status, (long long)i_size_read(inode)); |
| return status; |
| } |
| |
| static void nfs_writepage_release(struct nfs_page *req) |
| { |
| struct page *page = req->wb_page; |
| |
| if (PageError(req->wb_page) || !nfs_reschedule_unstable_write(req)) |
| nfs_inode_remove_request(req); |
| nfs_clear_page_tag_locked(req); |
| nfs_end_page_writeback(page); |
| } |
| |
| static int flush_task_priority(int how) |
| { |
| switch (how & (FLUSH_HIGHPRI|FLUSH_LOWPRI)) { |
| case FLUSH_HIGHPRI: |
| return RPC_PRIORITY_HIGH; |
| case FLUSH_LOWPRI: |
| return RPC_PRIORITY_LOW; |
| } |
| return RPC_PRIORITY_NORMAL; |
| } |
| |
| static int nfs_initiate_write(struct nfs_write_data *data, |
| struct rpc_clnt *clnt, |
| const struct rpc_call_ops *call_ops, |
| int how) |
| { |
| struct inode *inode = data->inode; |
| int priority = flush_task_priority(how); |
| struct rpc_task *task; |
| struct rpc_message msg = { |
| .rpc_argp = &data->args, |
| .rpc_resp = &data->res, |
| .rpc_cred = data->cred, |
| }; |
| struct rpc_task_setup task_setup_data = { |
| .rpc_client = clnt, |
| .task = &data->task, |
| .rpc_message = &msg, |
| .callback_ops = call_ops, |
| .callback_data = data, |
| .workqueue = nfsiod_workqueue, |
| .flags = RPC_TASK_ASYNC, |
| .priority = priority, |
| }; |
| int ret = 0; |
| |
| /* Set up the initial task struct. */ |
| NFS_PROTO(inode)->write_setup(data, &msg); |
| |
| dprintk("NFS: %5u initiated write call " |
| "(req %s/%lld, %u bytes @ offset %llu)\n", |
| data->task.tk_pid, |
| inode->i_sb->s_id, |
| (long long)NFS_FILEID(inode), |
| data->args.count, |
| (unsigned long long)data->args.offset); |
| |
| task = rpc_run_task(&task_setup_data); |
| if (IS_ERR(task)) { |
| ret = PTR_ERR(task); |
| goto out; |
| } |
| if (how & FLUSH_SYNC) { |
| ret = rpc_wait_for_completion_task(task); |
| if (ret == 0) |
| ret = task->tk_status; |
| } |
| rpc_put_task(task); |
| out: |
| return ret; |
| } |
| |
| /* |
| * Set up the argument/result storage required for the RPC call. |
| */ |
| static int nfs_write_rpcsetup(struct nfs_page *req, |
| struct nfs_write_data *data, |
| const struct rpc_call_ops *call_ops, |
| unsigned int count, unsigned int offset, |
| struct pnfs_layout_segment *lseg, |
| int how) |
| { |
| struct inode *inode = req->wb_context->path.dentry->d_inode; |
| |
| /* Set up the RPC argument and reply structs |
| * NB: take care not to mess about with data->commit et al. */ |
| |
| data->req = req; |
| data->inode = inode = req->wb_context->path.dentry->d_inode; |
| data->cred = req->wb_context->cred; |
| data->lseg = get_lseg(lseg); |
| |
| data->args.fh = NFS_FH(inode); |
| data->args.offset = req_offset(req) + offset; |
| data->args.pgbase = req->wb_pgbase + offset; |
| data->args.pages = data->pagevec; |
| data->args.count = count; |
| data->args.context = get_nfs_open_context(req->wb_context); |
| data->args.lock_context = req->wb_lock_context; |
| data->args.stable = NFS_UNSTABLE; |
| if (how & FLUSH_STABLE) { |
| data->args.stable = NFS_DATA_SYNC; |
| if (!nfs_need_commit(NFS_I(inode))) |
| data->args.stable = NFS_FILE_SYNC; |
| } |
| |
| data->res.fattr = &data->fattr; |
| data->res.count = count; |
| data->res.verf = &data->verf; |
| nfs_fattr_init(&data->fattr); |
| |
| return nfs_initiate_write(data, NFS_CLIENT(inode), call_ops, how); |
| } |
| |
| /* If a nfs_flush_* function fails, it should remove reqs from @head and |
| * call this on each, which will prepare them to be retried on next |
| * writeback using standard nfs. |
| */ |
| static void nfs_redirty_request(struct nfs_page *req) |
| { |
| struct page *page = req->wb_page; |
| |
| nfs_mark_request_dirty(req); |
| nfs_clear_page_tag_locked(req); |
| nfs_end_page_writeback(page); |
| } |
| |
| /* |
| * Generate multiple small requests to write out a single |
| * contiguous dirty area on one page. |
| */ |
| static int nfs_flush_multi(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int how, struct pnfs_layout_segment *lseg) |
| { |
| struct nfs_page *req = nfs_list_entry(head->next); |
| struct page *page = req->wb_page; |
| struct nfs_write_data *data; |
| size_t wsize = NFS_SERVER(inode)->wsize, nbytes; |
| unsigned int offset; |
| int requests = 0; |
| int ret = 0; |
| LIST_HEAD(list); |
| |
| nfs_list_remove_request(req); |
| |
| nbytes = count; |
| do { |
| size_t len = min(nbytes, wsize); |
| |
| data = nfs_writedata_alloc(1); |
| if (!data) |
| goto out_bad; |
| list_add(&data->pages, &list); |
| requests++; |
| nbytes -= len; |
| } while (nbytes != 0); |
| atomic_set(&req->wb_complete, requests); |
| |
| BUG_ON(lseg); |
| lseg = pnfs_update_layout(inode, req->wb_context, IOMODE_RW); |
| ClearPageError(page); |
| offset = 0; |
| nbytes = count; |
| do { |
| int ret2; |
| |
| data = list_entry(list.next, struct nfs_write_data, pages); |
| list_del_init(&data->pages); |
| |
| data->pagevec[0] = page; |
| |
| if (nbytes < wsize) |
| wsize = nbytes; |
| ret2 = nfs_write_rpcsetup(req, data, &nfs_write_partial_ops, |
| wsize, offset, lseg, how); |
| if (ret == 0) |
| ret = ret2; |
| offset += wsize; |
| nbytes -= wsize; |
| } while (nbytes != 0); |
| |
| put_lseg(lseg); |
| return ret; |
| |
| out_bad: |
| while (!list_empty(&list)) { |
| data = list_entry(list.next, struct nfs_write_data, pages); |
| list_del(&data->pages); |
| nfs_writedata_free(data); |
| } |
| nfs_redirty_request(req); |
| return -ENOMEM; |
| } |
| |
| /* |
| * Create an RPC task for the given write request and kick it. |
| * The page must have been locked by the caller. |
| * |
| * It may happen that the page we're passed is not marked dirty. |
| * This is the case if nfs_updatepage detects a conflicting request |
| * that has been written but not committed. |
| */ |
| static int nfs_flush_one(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int how, struct pnfs_layout_segment *lseg) |
| { |
| struct nfs_page *req; |
| struct page **pages; |
| struct nfs_write_data *data; |
| int ret; |
| |
| data = nfs_writedata_alloc(npages); |
| if (!data) { |
| while (!list_empty(head)) { |
| req = nfs_list_entry(head->next); |
| nfs_list_remove_request(req); |
| nfs_redirty_request(req); |
| } |
| ret = -ENOMEM; |
| goto out; |
| } |
| pages = data->pagevec; |
| while (!list_empty(head)) { |
| req = nfs_list_entry(head->next); |
| nfs_list_remove_request(req); |
| nfs_list_add_request(req, &data->pages); |
| ClearPageError(req->wb_page); |
| *pages++ = req->wb_page; |
| } |
| req = nfs_list_entry(data->pages.next); |
| if ((!lseg) && list_is_singular(&data->pages)) |
| lseg = pnfs_update_layout(inode, req->wb_context, IOMODE_RW); |
| |
| /* Set up the argument struct */ |
| ret = nfs_write_rpcsetup(req, data, &nfs_write_full_ops, count, 0, lseg, how); |
| out: |
| put_lseg(lseg); /* Cleans any gotten in ->pg_test */ |
| return ret; |
| } |
| |
| static void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, |
| struct inode *inode, int ioflags) |
| { |
| size_t wsize = NFS_SERVER(inode)->wsize; |
| |
| pnfs_pageio_init_write(pgio, inode); |
| |
| if (wsize < PAGE_CACHE_SIZE) |
| nfs_pageio_init(pgio, inode, nfs_flush_multi, wsize, ioflags); |
| else |
| nfs_pageio_init(pgio, inode, nfs_flush_one, wsize, ioflags); |
| } |
| |
| /* |
| * Handle a write reply that flushed part of a page. |
| */ |
| static void nfs_writeback_done_partial(struct rpc_task *task, void *calldata) |
| { |
| struct nfs_write_data *data = calldata; |
| |
| dprintk("NFS: %5u write(%s/%lld %d@%lld)", |
| task->tk_pid, |
| data->req->wb_context->path.dentry->d_inode->i_sb->s_id, |
| (long long) |
| NFS_FILEID(data->req->wb_context->path.dentry->d_inode), |
| data->req->wb_bytes, (long long)req_offset(data->req)); |
| |
| nfs_writeback_done(task, data); |
| } |
| |
| static void nfs_writeback_release_partial(void *calldata) |
| { |
| struct nfs_write_data *data = calldata; |
| struct nfs_page *req = data->req; |
| struct page *page = req->wb_page; |
| int status = data->task.tk_status; |
| |
| if (status < 0) { |
| nfs_set_pageerror(page); |
| nfs_context_set_write_error(req->wb_context, status); |
| dprintk(", error = %d\n", status); |
| goto out; |
| } |
| |
| if (nfs_write_need_commit(data)) { |
| struct inode *inode = page->mapping->host; |
| |
| spin_lock(&inode->i_lock); |
| if (test_bit(PG_NEED_RESCHED, &req->wb_flags)) { |
| /* Do nothing we need to resend the writes */ |
| } else if (!test_and_set_bit(PG_NEED_COMMIT, &req->wb_flags)) { |
| memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf)); |
| dprintk(" defer commit\n"); |
| } else if (memcmp(&req->wb_verf, &data->verf, sizeof(req->wb_verf))) { |
| set_bit(PG_NEED_RESCHED, &req->wb_flags); |
| clear_bit(PG_NEED_COMMIT, &req->wb_flags); |
| dprintk(" server reboot detected\n"); |
| } |
| spin_unlock(&inode->i_lock); |
| } else |
| dprintk(" OK\n"); |
| |
| out: |
| if (atomic_dec_and_test(&req->wb_complete)) |
| nfs_writepage_release(req); |
| nfs_writedata_release(calldata); |
| } |
| |
| #if defined(CONFIG_NFS_V4_1) |
| void nfs_write_prepare(struct rpc_task *task, void *calldata) |
| { |
| struct nfs_write_data *data = calldata; |
| |
| if (nfs4_setup_sequence(NFS_SERVER(data->inode), |
| &data->args.seq_args, |
| &data->res.seq_res, 1, task)) |
| return; |
| rpc_call_start(task); |
| } |
| #endif /* CONFIG_NFS_V4_1 */ |
| |
| static const struct rpc_call_ops nfs_write_partial_ops = { |
| #if defined(CONFIG_NFS_V4_1) |
| .rpc_call_prepare = nfs_write_prepare, |
| #endif /* CONFIG_NFS_V4_1 */ |
| .rpc_call_done = nfs_writeback_done_partial, |
| .rpc_release = nfs_writeback_release_partial, |
| }; |
| |
| /* |
| * Handle a write reply that flushes a whole page. |
| * |
| * FIXME: There is an inherent race with invalidate_inode_pages and |
| * writebacks since the page->count is kept > 1 for as long |
| * as the page has a write request pending. |
| */ |
| static void nfs_writeback_done_full(struct rpc_task *task, void *calldata) |
| { |
| struct nfs_write_data *data = calldata; |
| |
| nfs_writeback_done(task, data); |
| } |
| |
| static void nfs_writeback_release_full(void *calldata) |
| { |
| struct nfs_write_data *data = calldata; |
| int status = data->task.tk_status; |
| |
| /* Update attributes as result of writeback. */ |
| while (!list_empty(&data->pages)) { |
| struct nfs_page *req = nfs_list_entry(data->pages.next); |
| struct page *page = req->wb_page; |
| |
| nfs_list_remove_request(req); |
| |
| dprintk("NFS: %5u write (%s/%lld %d@%lld)", |
| data->task.tk_pid, |
| req->wb_context->path.dentry->d_inode->i_sb->s_id, |
| (long long)NFS_FILEID(req->wb_context->path.dentry->d_inode), |
| req->wb_bytes, |
| (long long)req_offset(req)); |
| |
| if (status < 0) { |
| nfs_set_pageerror(page); |
| nfs_context_set_write_error(req->wb_context, status); |
| dprintk(", error = %d\n", status); |
| goto remove_request; |
| } |
| |
| if (nfs_write_need_commit(data)) { |
| memcpy(&req->wb_verf, &data->verf, sizeof(req->wb_verf)); |
| nfs_mark_request_commit(req); |
| dprintk(" marked for commit\n"); |
| goto next; |
| } |
| dprintk(" OK\n"); |
| remove_request: |
| nfs_inode_remove_request(req); |
| next: |
| nfs_clear_page_tag_locked(req); |
| nfs_end_page_writeback(page); |
| } |
| nfs_writedata_release(calldata); |
| } |
| |
| static const struct rpc_call_ops nfs_write_full_ops = { |
| #if defined(CONFIG_NFS_V4_1) |
| .rpc_call_prepare = nfs_write_prepare, |
| #endif /* CONFIG_NFS_V4_1 */ |
| .rpc_call_done = nfs_writeback_done_full, |
| .rpc_release = nfs_writeback_release_full, |
| }; |
| |
| |
| /* |
| * This function is called when the WRITE call is complete. |
| */ |
| void nfs_writeback_done(struct rpc_task *task, struct nfs_write_data *data) |
| { |
| struct nfs_writeargs *argp = &data->args; |
| struct nfs_writeres *resp = &data->res; |
| struct nfs_server *server = NFS_SERVER(data->inode); |
| int status; |
| |
| dprintk("NFS: %5u nfs_writeback_done (status %d)\n", |
| task->tk_pid, task->tk_status); |
| |
| /* |
| * ->write_done will attempt to use post-op attributes to detect |
| * conflicting writes by other clients. A strict interpretation |
| * of close-to-open would allow us to continue caching even if |
| * another writer had changed the file, but some applications |
| * depend on tighter cache coherency when writing. |
| */ |
| status = NFS_PROTO(data->inode)->write_done(task, data); |
| if (status != 0) |
| return; |
| nfs_add_stats(data->inode, NFSIOS_SERVERWRITTENBYTES, resp->count); |
| |
| #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) |
| if (resp->verf->committed < argp->stable && task->tk_status >= 0) { |
| /* We tried a write call, but the server did not |
| * commit data to stable storage even though we |
| * requested it. |
| * Note: There is a known bug in Tru64 < 5.0 in which |
| * the server reports NFS_DATA_SYNC, but performs |
| * NFS_FILE_SYNC. We therefore implement this checking |
| * as a dprintk() in order to avoid filling syslog. |
| */ |
| static unsigned long complain; |
| |
| if (time_before(complain, jiffies)) { |
| dprintk("NFS: faulty NFS server %s:" |
| " (committed = %d) != (stable = %d)\n", |
| server->nfs_client->cl_hostname, |
| resp->verf->committed, argp->stable); |
| complain = jiffies + 300 * HZ; |
| } |
| } |
| #endif |
| /* Is this a short write? */ |
| if (task->tk_status >= 0 && resp->count < argp->count) { |
| static unsigned long complain; |
| |
| nfs_inc_stats(data->inode, NFSIOS_SHORTWRITE); |
| |
| /* Has the server at least made some progress? */ |
| if (resp->count != 0) { |
| /* Was this an NFSv2 write or an NFSv3 stable write? */ |
| if (resp->verf->committed != NFS_UNSTABLE) { |
| /* Resend from where the server left off */ |
| argp->offset += resp->count; |
| argp->pgbase += resp->count; |
| argp->count -= resp->count; |
| } else { |
| /* Resend as a stable write in order to avoid |
| * headaches in the case of a server crash. |
| */ |
| argp->stable = NFS_FILE_SYNC; |
| } |
| nfs_restart_rpc(task, server->nfs_client); |
| return; |
| } |
| if (time_before(complain, jiffies)) { |
| printk(KERN_WARNING |
| "NFS: Server wrote zero bytes, expected %u.\n", |
| argp->count); |
| complain = jiffies + 300 * HZ; |
| } |
| /* Can't do anything about it except throw an error. */ |
| task->tk_status = -EIO; |
| } |
| return; |
| } |
| |
| |
| #if defined(CONFIG_NFS_V3) || defined(CONFIG_NFS_V4) |
| static int nfs_commit_set_lock(struct nfs_inode *nfsi, int may_wait) |
| { |
| if (!test_and_set_bit(NFS_INO_COMMIT, &nfsi->flags)) |
| return 1; |
| if (may_wait && !out_of_line_wait_on_bit_lock(&nfsi->flags, |
| NFS_INO_COMMIT, nfs_wait_bit_killable, |
| TASK_KILLABLE)) |
| return 1; |
| return 0; |
| } |
| |
| static void nfs_commit_clear_lock(struct nfs_inode *nfsi) |
| { |
| clear_bit(NFS_INO_COMMIT, &nfsi->flags); |
| smp_mb__after_clear_bit(); |
| wake_up_bit(&nfsi->flags, NFS_INO_COMMIT); |
| } |
| |
| |
| static void nfs_commitdata_release(void *data) |
| { |
| struct nfs_write_data *wdata = data; |
| |
| put_nfs_open_context(wdata->args.context); |
| nfs_commit_free(wdata); |
| } |
| |
| /* |
| * Set up the argument/result storage required for the RPC call. |
| */ |
| static int nfs_commit_rpcsetup(struct list_head *head, |
| struct nfs_write_data *data, |
| int how) |
| { |
| struct nfs_page *first = nfs_list_entry(head->next); |
| struct inode *inode = first->wb_context->path.dentry->d_inode; |
| int priority = flush_task_priority(how); |
| struct rpc_task *task; |
| struct rpc_message msg = { |
| .rpc_argp = &data->args, |
| .rpc_resp = &data->res, |
| .rpc_cred = first->wb_context->cred, |
| }; |
| struct rpc_task_setup task_setup_data = { |
| .task = &data->task, |
| .rpc_client = NFS_CLIENT(inode), |
| .rpc_message = &msg, |
| .callback_ops = &nfs_commit_ops, |
| .callback_data = data, |
| .workqueue = nfsiod_workqueue, |
| .flags = RPC_TASK_ASYNC, |
| .priority = priority, |
| }; |
| |
| /* Set up the RPC argument and reply structs |
| * NB: take care not to mess about with data->commit et al. */ |
| |
| list_splice_init(head, &data->pages); |
| |
| data->inode = inode; |
| data->cred = msg.rpc_cred; |
| |
| data->args.fh = NFS_FH(data->inode); |
| /* Note: we always request a commit of the entire inode */ |
| data->args.offset = 0; |
| data->args.count = 0; |
| data->args.context = get_nfs_open_context(first->wb_context); |
| data->res.count = 0; |
| data->res.fattr = &data->fattr; |
| data->res.verf = &data->verf; |
| nfs_fattr_init(&data->fattr); |
| |
| /* Set up the initial task struct. */ |
| NFS_PROTO(inode)->commit_setup(data, &msg); |
| |
| dprintk("NFS: %5u initiated commit call\n", data->task.tk_pid); |
| |
| task = rpc_run_task(&task_setup_data); |
| if (IS_ERR(task)) |
| return PTR_ERR(task); |
| if (how & FLUSH_SYNC) |
| rpc_wait_for_completion_task(task); |
| rpc_put_task(task); |
| return 0; |
| } |
| |
| /* |
| * Commit dirty pages |
| */ |
| static int |
| nfs_commit_list(struct inode *inode, struct list_head *head, int how) |
| { |
| struct nfs_write_data *data; |
| struct nfs_page *req; |
| |
| data = nfs_commitdata_alloc(); |
| |
| if (!data) |
| goto out_bad; |
| |
| /* Set up the argument struct */ |
| return nfs_commit_rpcsetup(head, data, how); |
| out_bad: |
| while (!list_empty(head)) { |
| req = nfs_list_entry(head->next); |
| nfs_list_remove_request(req); |
| nfs_mark_request_commit(req); |
| dec_zone_page_state(req->wb_page, NR_UNSTABLE_NFS); |
| dec_bdi_stat(req->wb_page->mapping->backing_dev_info, |
| BDI_RECLAIMABLE); |
| nfs_clear_page_tag_locked(req); |
| } |
| nfs_commit_clear_lock(NFS_I(inode)); |
| return -ENOMEM; |
| } |
| |
| /* |
| * COMMIT call returned |
| */ |
| static void nfs_commit_done(struct rpc_task *task, void *calldata) |
| { |
| struct nfs_write_data *data = calldata; |
| |
| dprintk("NFS: %5u nfs_commit_done (status %d)\n", |
| task->tk_pid, task->tk_status); |
| |
| /* Call the NFS version-specific code */ |
| if (NFS_PROTO(data->inode)->commit_done(task, data) != 0) |
| return; |
| } |
| |
| static void nfs_commit_release(void *calldata) |
| { |
| struct nfs_write_data *data = calldata; |
| struct nfs_page *req; |
| int status = data->task.tk_status; |
| |
| while (!list_empty(&data->pages)) { |
| req = nfs_list_entry(data->pages.next); |
| nfs_list_remove_request(req); |
| nfs_clear_request_commit(req); |
| |
| dprintk("NFS: commit (%s/%lld %d@%lld)", |
| req->wb_context->path.dentry->d_inode->i_sb->s_id, |
| (long long)NFS_FILEID(req->wb_context->path.dentry->d_inode), |
| req->wb_bytes, |
| (long long)req_offset(req)); |
| if (status < 0) { |
| nfs_context_set_write_error(req->wb_context, status); |
| nfs_inode_remove_request(req); |
| dprintk(", error = %d\n", status); |
| goto next; |
| } |
| |
| /* Okay, COMMIT succeeded, apparently. Check the verifier |
| * returned by the server against all stored verfs. */ |
| if (!memcmp(req->wb_verf.verifier, data->verf.verifier, sizeof(data->verf.verifier))) { |
| /* We have a match */ |
| nfs_inode_remove_request(req); |
| dprintk(" OK\n"); |
| goto next; |
| } |
| /* We have a mismatch. Write the page again */ |
| dprintk(" mismatch\n"); |
| nfs_mark_request_dirty(req); |
| next: |
| nfs_clear_page_tag_locked(req); |
| } |
| nfs_commit_clear_lock(NFS_I(data->inode)); |
| nfs_commitdata_release(calldata); |
| } |
| |
| static const struct rpc_call_ops nfs_commit_ops = { |
| #if defined(CONFIG_NFS_V4_1) |
| .rpc_call_prepare = nfs_write_prepare, |
| #endif /* CONFIG_NFS_V4_1 */ |
| .rpc_call_done = nfs_commit_done, |
| .rpc_release = nfs_commit_release, |
| }; |
| |
| int nfs_commit_inode(struct inode *inode, int how) |
| { |
| LIST_HEAD(head); |
| int may_wait = how & FLUSH_SYNC; |
| int res = 0; |
| |
| if (!nfs_commit_set_lock(NFS_I(inode), may_wait)) |
| goto out_mark_dirty; |
| spin_lock(&inode->i_lock); |
| res = nfs_scan_commit(inode, &head, 0, 0); |
| spin_unlock(&inode->i_lock); |
| if (res) { |
| int error = nfs_commit_list(inode, &head, how); |
| if (error < 0) |
| return error; |
| if (may_wait) |
| wait_on_bit(&NFS_I(inode)->flags, NFS_INO_COMMIT, |
| nfs_wait_bit_killable, |
| TASK_KILLABLE); |
| else |
| goto out_mark_dirty; |
| } else |
| nfs_commit_clear_lock(NFS_I(inode)); |
| return res; |
| /* Note: If we exit without ensuring that the commit is complete, |
| * we must mark the inode as dirty. Otherwise, future calls to |
| * sync_inode() with the WB_SYNC_ALL flag set will fail to ensure |
| * that the data is on the disk. |
| */ |
| out_mark_dirty: |
| __mark_inode_dirty(inode, I_DIRTY_DATASYNC); |
| return res; |
| } |
| |
| static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc) |
| { |
| struct nfs_inode *nfsi = NFS_I(inode); |
| int flags = FLUSH_SYNC; |
| int ret = 0; |
| |
| if (wbc->sync_mode == WB_SYNC_NONE) { |
| /* Don't commit yet if this is a non-blocking flush and there |
| * are a lot of outstanding writes for this mapping. |
| */ |
| if (nfsi->ncommit <= (nfsi->npages >> 1)) |
| goto out_mark_dirty; |
| |
| /* don't wait for the COMMIT response */ |
| flags = 0; |
| } |
| |
| ret = nfs_commit_inode(inode, flags); |
| if (ret >= 0) { |
| if (wbc->sync_mode == WB_SYNC_NONE) { |
| if (ret < wbc->nr_to_write) |
| wbc->nr_to_write -= ret; |
| else |
| wbc->nr_to_write = 0; |
| } |
| return 0; |
| } |
| out_mark_dirty: |
| __mark_inode_dirty(inode, I_DIRTY_DATASYNC); |
| return ret; |
| } |
| #else |
| static int nfs_commit_unstable_pages(struct inode *inode, struct writeback_control *wbc) |
| { |
| return 0; |
| } |
| #endif |
| |
| int nfs_write_inode(struct inode *inode, struct writeback_control *wbc) |
| { |
| return nfs_commit_unstable_pages(inode, wbc); |
| } |
| |
| /* |
| * flush the inode to disk. |
| */ |
| int nfs_wb_all(struct inode *inode) |
| { |
| struct writeback_control wbc = { |
| .sync_mode = WB_SYNC_ALL, |
| .nr_to_write = LONG_MAX, |
| .range_start = 0, |
| .range_end = LLONG_MAX, |
| }; |
| |
| return sync_inode(inode, &wbc); |
| } |
| |
| int nfs_wb_page_cancel(struct inode *inode, struct page *page) |
| { |
| struct nfs_page *req; |
| int ret = 0; |
| |
| BUG_ON(!PageLocked(page)); |
| for (;;) { |
| wait_on_page_writeback(page); |
| req = nfs_page_find_request(page); |
| if (req == NULL) |
| break; |
| if (nfs_lock_request_dontget(req)) { |
| nfs_inode_remove_request(req); |
| /* |
| * In case nfs_inode_remove_request has marked the |
| * page as being dirty |
| */ |
| cancel_dirty_page(page, PAGE_CACHE_SIZE); |
| nfs_unlock_request(req); |
| break; |
| } |
| ret = nfs_wait_on_request(req); |
| nfs_release_request(req); |
| if (ret < 0) |
| break; |
| } |
| return ret; |
| } |
| |
| /* |
| * Write back all requests on one page - we do this before reading it. |
| */ |
| int nfs_wb_page(struct inode *inode, struct page *page) |
| { |
| loff_t range_start = page_offset(page); |
| loff_t range_end = range_start + (loff_t)(PAGE_CACHE_SIZE - 1); |
| struct writeback_control wbc = { |
| .sync_mode = WB_SYNC_ALL, |
| .nr_to_write = 0, |
| .range_start = range_start, |
| .range_end = range_end, |
| }; |
| int ret; |
| |
| for (;;) { |
| wait_on_page_writeback(page); |
| if (clear_page_dirty_for_io(page)) { |
| ret = nfs_writepage_locked(page, &wbc); |
| if (ret < 0) |
| goto out_error; |
| continue; |
| } |
| if (!PagePrivate(page)) |
| break; |
| ret = nfs_commit_inode(inode, FLUSH_SYNC); |
| if (ret < 0) |
| goto out_error; |
| } |
| return 0; |
| out_error: |
| return ret; |
| } |
| |
| #ifdef CONFIG_MIGRATION |
| int nfs_migrate_page(struct address_space *mapping, struct page *newpage, |
| struct page *page) |
| { |
| struct nfs_page *req; |
| int ret; |
| |
| nfs_fscache_release_page(page, GFP_KERNEL); |
| |
| req = nfs_find_and_lock_request(page, false); |
| ret = PTR_ERR(req); |
| if (IS_ERR(req)) |
| goto out; |
| |
| ret = migrate_page(mapping, newpage, page); |
| if (!req) |
| goto out; |
| if (ret) |
| goto out_unlock; |
| page_cache_get(newpage); |
| spin_lock(&mapping->host->i_lock); |
| req->wb_page = newpage; |
| SetPagePrivate(newpage); |
| set_page_private(newpage, (unsigned long)req); |
| ClearPagePrivate(page); |
| set_page_private(page, 0); |
| spin_unlock(&mapping->host->i_lock); |
| page_cache_release(page); |
| out_unlock: |
| nfs_clear_page_tag_locked(req); |
| out: |
| return ret; |
| } |
| #endif |
| |
| int __init nfs_init_writepagecache(void) |
| { |
| nfs_wdata_cachep = kmem_cache_create("nfs_write_data", |
| sizeof(struct nfs_write_data), |
| 0, SLAB_HWCACHE_ALIGN, |
| NULL); |
| if (nfs_wdata_cachep == NULL) |
| return -ENOMEM; |
| |
| nfs_wdata_mempool = mempool_create_slab_pool(MIN_POOL_WRITE, |
| nfs_wdata_cachep); |
| if (nfs_wdata_mempool == NULL) |
| return -ENOMEM; |
| |
| nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT, |
| nfs_wdata_cachep); |
| if (nfs_commit_mempool == NULL) |
| return -ENOMEM; |
| |
| /* |
| * NFS congestion size, scale with available memory. |
| * |
| * 64MB: 8192k |
| * 128MB: 11585k |
| * 256MB: 16384k |
| * 512MB: 23170k |
| * 1GB: 32768k |
| * 2GB: 46340k |
| * 4GB: 65536k |
| * 8GB: 92681k |
| * 16GB: 131072k |
| * |
| * This allows larger machines to have larger/more transfers. |
| * Limit the default to 256M |
| */ |
| nfs_congestion_kb = (16*int_sqrt(totalram_pages)) << (PAGE_SHIFT-10); |
| if (nfs_congestion_kb > 256*1024) |
| nfs_congestion_kb = 256*1024; |
| |
| return 0; |
| } |
| |
| void nfs_destroy_writepagecache(void) |
| { |
| mempool_destroy(nfs_commit_mempool); |
| mempool_destroy(nfs_wdata_mempool); |
| kmem_cache_destroy(nfs_wdata_cachep); |
| } |
| |