| /* |
| * 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 <linux/export.h> |
| |
| #include <asm/uaccess.h> |
| |
| #include "delegation.h" |
| #include "internal.h" |
| #include "iostat.h" |
| #include "nfs4_fs.h" |
| #include "fscache.h" |
| #include "pnfs.h" |
| |
| #include "nfstrace.h" |
| |
| #define NFSDBG_FACILITY NFSDBG_PAGECACHE |
| |
| #define MIN_POOL_WRITE (32) |
| #define MIN_POOL_COMMIT (4) |
| |
| /* |
| * Local function declarations |
| */ |
| static void nfs_redirty_request(struct nfs_page *req); |
| static const struct rpc_call_ops nfs_commit_ops; |
| static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops; |
| static const struct nfs_commit_completion_ops nfs_commit_completion_ops; |
| static const struct nfs_rw_ops nfs_rw_write_ops; |
| static void nfs_clear_request_commit(struct nfs_page *req); |
| static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo, |
| struct inode *inode); |
| static struct nfs_page * |
| nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi, |
| struct page *page); |
| |
| static struct kmem_cache *nfs_wdata_cachep; |
| static mempool_t *nfs_wdata_mempool; |
| static struct kmem_cache *nfs_cdata_cachep; |
| static mempool_t *nfs_commit_mempool; |
| |
| struct nfs_commit_data *nfs_commitdata_alloc(void) |
| { |
| struct nfs_commit_data *p = mempool_alloc(nfs_commit_mempool, GFP_NOIO); |
| |
| if (p) { |
| memset(p, 0, sizeof(*p)); |
| INIT_LIST_HEAD(&p->pages); |
| } |
| return p; |
| } |
| EXPORT_SYMBOL_GPL(nfs_commitdata_alloc); |
| |
| void nfs_commit_free(struct nfs_commit_data *p) |
| { |
| mempool_free(p, nfs_commit_mempool); |
| } |
| EXPORT_SYMBOL_GPL(nfs_commit_free); |
| |
| static struct nfs_pgio_header *nfs_writehdr_alloc(void) |
| { |
| struct nfs_pgio_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO); |
| |
| if (p) |
| memset(p, 0, sizeof(*p)); |
| return p; |
| } |
| |
| static void nfs_writehdr_free(struct nfs_pgio_header *hdr) |
| { |
| mempool_free(hdr, nfs_wdata_mempool); |
| } |
| |
| 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); |
| } |
| |
| /* |
| * nfs_page_find_head_request_locked - find head request associated with @page |
| * |
| * must be called while holding the inode lock. |
| * |
| * returns matching head request with reference held, or NULL if not found. |
| */ |
| static struct nfs_page * |
| nfs_page_find_head_request_locked(struct nfs_inode *nfsi, struct page *page) |
| { |
| struct nfs_page *req = NULL; |
| |
| if (PagePrivate(page)) |
| req = (struct nfs_page *)page_private(page); |
| else if (unlikely(PageSwapCache(page))) |
| req = nfs_page_search_commits_for_head_request_locked(nfsi, |
| page); |
| |
| if (req) { |
| WARN_ON_ONCE(req->wb_head != req); |
| kref_get(&req->wb_kref); |
| } |
| |
| return req; |
| } |
| |
| /* |
| * nfs_page_find_head_request - find head request associated with @page |
| * |
| * returns matching head request with reference held, or NULL if not found. |
| */ |
| static struct nfs_page *nfs_page_find_head_request(struct page *page) |
| { |
| struct inode *inode = page_file_mapping(page)->host; |
| struct nfs_page *req = NULL; |
| |
| spin_lock(&inode->i_lock); |
| req = nfs_page_find_head_request_locked(NFS_I(inode), 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_file_mapping(page)->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_file_index(page) < end_index) |
| goto out; |
| end = page_file_offset(page) + ((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) |
| { |
| nfs_zap_mapping(page_file_mapping(page)->host, page_file_mapping(page)); |
| } |
| |
| /* |
| * nfs_page_group_search_locked |
| * @head - head request of page group |
| * @page_offset - offset into page |
| * |
| * Search page group with head @head to find a request that contains the |
| * page offset @page_offset. |
| * |
| * Returns a pointer to the first matching nfs request, or NULL if no |
| * match is found. |
| * |
| * Must be called with the page group lock held |
| */ |
| static struct nfs_page * |
| nfs_page_group_search_locked(struct nfs_page *head, unsigned int page_offset) |
| { |
| struct nfs_page *req; |
| |
| WARN_ON_ONCE(head != head->wb_head); |
| WARN_ON_ONCE(!test_bit(PG_HEADLOCK, &head->wb_head->wb_flags)); |
| |
| req = head; |
| do { |
| if (page_offset >= req->wb_pgbase && |
| page_offset < (req->wb_pgbase + req->wb_bytes)) |
| return req; |
| |
| req = req->wb_this_page; |
| } while (req != head); |
| |
| return NULL; |
| } |
| |
| /* |
| * nfs_page_group_covers_page |
| * @head - head request of page group |
| * |
| * Return true if the page group with head @head covers the whole page, |
| * returns false otherwise |
| */ |
| static bool nfs_page_group_covers_page(struct nfs_page *req) |
| { |
| struct nfs_page *tmp; |
| unsigned int pos = 0; |
| unsigned int len = nfs_page_length(req->wb_page); |
| |
| nfs_page_group_lock(req, false); |
| |
| do { |
| tmp = nfs_page_group_search_locked(req->wb_head, pos); |
| if (tmp) { |
| /* no way this should happen */ |
| WARN_ON_ONCE(tmp->wb_pgbase != pos); |
| pos += tmp->wb_bytes - (pos - tmp->wb_pgbase); |
| } |
| } while (tmp && pos < len); |
| |
| nfs_page_group_unlock(req); |
| WARN_ON_ONCE(pos > len); |
| return pos == len; |
| } |
| |
| /* We can set the PG_uptodate flag if we see that a write request |
| * covers the full page. |
| */ |
| static void nfs_mark_uptodate(struct nfs_page *req) |
| { |
| if (PageUptodate(req->wb_page)) |
| return; |
| if (!nfs_page_group_covers_page(req)) |
| return; |
| SetPageUptodate(req->wb_page); |
| } |
| |
| static int wb_priority(struct writeback_control *wbc) |
| { |
| int ret = 0; |
| if (wbc->for_reclaim) |
| return FLUSH_HIGHPRI | FLUSH_STABLE; |
| if (wbc->sync_mode == WB_SYNC_ALL) |
| ret = FLUSH_COND_STABLE; |
| if (wbc->for_kupdate || wbc->for_background) |
| ret |= FLUSH_LOWPRI; |
| return ret; |
| } |
| |
| /* |
| * 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 void nfs_set_page_writeback(struct page *page) |
| { |
| struct nfs_server *nfss = NFS_SERVER(page_file_mapping(page)->host); |
| int ret = test_set_page_writeback(page); |
| |
| WARN_ON_ONCE(ret != 0); |
| |
| if (atomic_long_inc_return(&nfss->writeback) > |
| NFS_CONGESTION_ON_THRESH) { |
| set_bdi_congested(&nfss->backing_dev_info, |
| BLK_RW_ASYNC); |
| } |
| } |
| |
| static void nfs_end_page_writeback(struct nfs_page *req) |
| { |
| struct inode *inode = page_file_mapping(req->wb_page)->host; |
| struct nfs_server *nfss = NFS_SERVER(inode); |
| |
| if (!nfs_page_group_sync_on_bit(req, PG_WB_END)) |
| return; |
| |
| end_page_writeback(req->wb_page); |
| if (atomic_long_dec_return(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) |
| clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC); |
| } |
| |
| |
| /* nfs_page_group_clear_bits |
| * @req - an nfs request |
| * clears all page group related bits from @req |
| */ |
| static void |
| nfs_page_group_clear_bits(struct nfs_page *req) |
| { |
| clear_bit(PG_TEARDOWN, &req->wb_flags); |
| clear_bit(PG_UNLOCKPAGE, &req->wb_flags); |
| clear_bit(PG_UPTODATE, &req->wb_flags); |
| clear_bit(PG_WB_END, &req->wb_flags); |
| clear_bit(PG_REMOVE, &req->wb_flags); |
| } |
| |
| |
| /* |
| * nfs_unroll_locks_and_wait - unlock all newly locked reqs and wait on @req |
| * |
| * this is a helper function for nfs_lock_and_join_requests |
| * |
| * @inode - inode associated with request page group, must be holding inode lock |
| * @head - head request of page group, must be holding head lock |
| * @req - request that couldn't lock and needs to wait on the req bit lock |
| * @nonblock - if true, don't actually wait |
| * |
| * NOTE: this must be called holding page_group bit lock and inode spin lock |
| * and BOTH will be released before returning. |
| * |
| * returns 0 on success, < 0 on error. |
| */ |
| static int |
| nfs_unroll_locks_and_wait(struct inode *inode, struct nfs_page *head, |
| struct nfs_page *req, bool nonblock) |
| __releases(&inode->i_lock) |
| { |
| struct nfs_page *tmp; |
| int ret; |
| |
| /* relinquish all the locks successfully grabbed this run */ |
| for (tmp = head ; tmp != req; tmp = tmp->wb_this_page) |
| nfs_unlock_request(tmp); |
| |
| WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags)); |
| |
| /* grab a ref on the request that will be waited on */ |
| kref_get(&req->wb_kref); |
| |
| nfs_page_group_unlock(head); |
| spin_unlock(&inode->i_lock); |
| |
| /* release ref from nfs_page_find_head_request_locked */ |
| nfs_release_request(head); |
| |
| if (!nonblock) |
| ret = nfs_wait_on_request(req); |
| else |
| ret = -EAGAIN; |
| nfs_release_request(req); |
| |
| return ret; |
| } |
| |
| /* |
| * nfs_destroy_unlinked_subrequests - destroy recently unlinked subrequests |
| * |
| * @destroy_list - request list (using wb_this_page) terminated by @old_head |
| * @old_head - the old head of the list |
| * |
| * All subrequests must be locked and removed from all lists, so at this point |
| * they are only "active" in this function, and possibly in nfs_wait_on_request |
| * with a reference held by some other context. |
| */ |
| static void |
| nfs_destroy_unlinked_subrequests(struct nfs_page *destroy_list, |
| struct nfs_page *old_head) |
| { |
| while (destroy_list) { |
| struct nfs_page *subreq = destroy_list; |
| |
| destroy_list = (subreq->wb_this_page == old_head) ? |
| NULL : subreq->wb_this_page; |
| |
| WARN_ON_ONCE(old_head != subreq->wb_head); |
| |
| /* make sure old group is not used */ |
| subreq->wb_head = subreq; |
| subreq->wb_this_page = subreq; |
| |
| /* subreq is now totally disconnected from page group or any |
| * write / commit lists. last chance to wake any waiters */ |
| nfs_unlock_request(subreq); |
| |
| if (!test_bit(PG_TEARDOWN, &subreq->wb_flags)) { |
| /* release ref on old head request */ |
| nfs_release_request(old_head); |
| |
| nfs_page_group_clear_bits(subreq); |
| |
| /* release the PG_INODE_REF reference */ |
| if (test_and_clear_bit(PG_INODE_REF, &subreq->wb_flags)) |
| nfs_release_request(subreq); |
| else |
| WARN_ON_ONCE(1); |
| } else { |
| WARN_ON_ONCE(test_bit(PG_CLEAN, &subreq->wb_flags)); |
| /* zombie requests have already released the last |
| * reference and were waiting on the rest of the |
| * group to complete. Since it's no longer part of a |
| * group, simply free the request */ |
| nfs_page_group_clear_bits(subreq); |
| nfs_free_request(subreq); |
| } |
| } |
| } |
| |
| /* |
| * nfs_lock_and_join_requests - join all subreqs to the head req and return |
| * a locked reference, cancelling any pending |
| * operations for this page. |
| * |
| * @page - the page used to lookup the "page group" of nfs_page structures |
| * @nonblock - if true, don't block waiting for request locks |
| * |
| * This function joins all sub requests to the head request by first |
| * locking all requests in the group, cancelling any pending operations |
| * and finally updating the head request to cover the whole range covered by |
| * the (former) group. All subrequests are removed from any write or commit |
| * lists, unlinked from the group and destroyed. |
| * |
| * Returns a locked, referenced pointer to the head request - which after |
| * this call is guaranteed to be the only request associated with the page. |
| * Returns NULL if no requests are found for @page, or a ERR_PTR if an |
| * error was encountered. |
| */ |
| static struct nfs_page * |
| nfs_lock_and_join_requests(struct page *page, bool nonblock) |
| { |
| struct inode *inode = page_file_mapping(page)->host; |
| struct nfs_page *head, *subreq; |
| struct nfs_page *destroy_list = NULL; |
| unsigned int total_bytes; |
| int ret; |
| |
| try_again: |
| total_bytes = 0; |
| |
| WARN_ON_ONCE(destroy_list); |
| |
| spin_lock(&inode->i_lock); |
| |
| /* |
| * A reference is taken only on the head request which acts as a |
| * reference to the whole page group - the group will not be destroyed |
| * until the head reference is released. |
| */ |
| head = nfs_page_find_head_request_locked(NFS_I(inode), page); |
| |
| if (!head) { |
| spin_unlock(&inode->i_lock); |
| return NULL; |
| } |
| |
| /* holding inode lock, so always make a non-blocking call to try the |
| * page group lock */ |
| ret = nfs_page_group_lock(head, true); |
| if (ret < 0) { |
| spin_unlock(&inode->i_lock); |
| |
| if (!nonblock && ret == -EAGAIN) { |
| nfs_page_group_lock_wait(head); |
| nfs_release_request(head); |
| goto try_again; |
| } |
| |
| nfs_release_request(head); |
| return ERR_PTR(ret); |
| } |
| |
| /* lock each request in the page group */ |
| subreq = head; |
| do { |
| /* |
| * Subrequests are always contiguous, non overlapping |
| * and in order - but may be repeated (mirrored writes). |
| */ |
| if (subreq->wb_offset == (head->wb_offset + total_bytes)) { |
| /* keep track of how many bytes this group covers */ |
| total_bytes += subreq->wb_bytes; |
| } else if (WARN_ON_ONCE(subreq->wb_offset < head->wb_offset || |
| ((subreq->wb_offset + subreq->wb_bytes) > |
| (head->wb_offset + total_bytes)))) { |
| nfs_page_group_unlock(head); |
| spin_unlock(&inode->i_lock); |
| return ERR_PTR(-EIO); |
| } |
| |
| if (!nfs_lock_request(subreq)) { |
| /* releases page group bit lock and |
| * inode spin lock and all references */ |
| ret = nfs_unroll_locks_and_wait(inode, head, |
| subreq, nonblock); |
| |
| if (ret == 0) |
| goto try_again; |
| |
| return ERR_PTR(ret); |
| } |
| |
| subreq = subreq->wb_this_page; |
| } while (subreq != head); |
| |
| /* Now that all requests are locked, make sure they aren't on any list. |
| * Commit list removal accounting is done after locks are dropped */ |
| subreq = head; |
| do { |
| nfs_clear_request_commit(subreq); |
| subreq = subreq->wb_this_page; |
| } while (subreq != head); |
| |
| /* unlink subrequests from head, destroy them later */ |
| if (head->wb_this_page != head) { |
| /* destroy list will be terminated by head */ |
| destroy_list = head->wb_this_page; |
| head->wb_this_page = head; |
| |
| /* change head request to cover whole range that |
| * the former page group covered */ |
| head->wb_bytes = total_bytes; |
| } |
| |
| /* |
| * prepare head request to be added to new pgio descriptor |
| */ |
| nfs_page_group_clear_bits(head); |
| |
| /* |
| * some part of the group was still on the inode list - otherwise |
| * the group wouldn't be involved in async write. |
| * grab a reference for the head request, iff it needs one. |
| */ |
| if (!test_and_set_bit(PG_INODE_REF, &head->wb_flags)) |
| kref_get(&head->wb_kref); |
| |
| nfs_page_group_unlock(head); |
| |
| /* drop lock to clean uprequests on destroy list */ |
| spin_unlock(&inode->i_lock); |
| |
| nfs_destroy_unlinked_subrequests(destroy_list, head); |
| |
| /* still holds ref on head from nfs_page_find_head_request_locked |
| * and still has lock on head from lock loop */ |
| return head; |
| } |
| |
| /* |
| * 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_lock_and_join_requests(page, nonblock); |
| if (!req) |
| goto out; |
| ret = PTR_ERR(req); |
| if (IS_ERR(req)) |
| goto out; |
| |
| nfs_set_page_writeback(page); |
| WARN_ON_ONCE(test_bit(PG_CLEAN, &req->wb_flags)); |
| |
| ret = 0; |
| if (!nfs_pageio_add_request(pgio, req)) { |
| nfs_redirty_request(req); |
| ret = pgio->pg_error; |
| } else |
| nfs_add_stats(page_file_mapping(page)->host, |
| NFSIOS_WRITEPAGES, 1); |
| out: |
| return ret; |
| } |
| |
| static int nfs_do_writepage(struct page *page, struct writeback_control *wbc, struct nfs_pageio_descriptor *pgio) |
| { |
| int ret; |
| |
| nfs_pageio_cond_complete(pgio, page_file_index(page)); |
| 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; |
| struct inode *inode = page_file_mapping(page)->host; |
| int err; |
| |
| nfs_inc_stats(inode, NFSIOS_VFSWRITEPAGE); |
| nfs_pageio_init_write(&pgio, inode, wb_priority(wbc), |
| false, &nfs_async_write_completion_ops); |
| 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_action(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), false, |
| &nfs_async_write_completion_ops); |
| err = write_cache_pages(mapping, wbc, nfs_writepages_callback, &pgio); |
| nfs_pageio_complete(&pgio); |
| |
| clear_bit_unlock(NFS_INO_FLUSHING, bitlock); |
| smp_mb__after_atomic(); |
| 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 void nfs_inode_add_request(struct inode *inode, struct nfs_page *req) |
| { |
| struct nfs_inode *nfsi = NFS_I(inode); |
| |
| WARN_ON_ONCE(req->wb_this_page != req); |
| |
| /* Lock the request! */ |
| nfs_lock_request(req); |
| |
| spin_lock(&inode->i_lock); |
| if (!nfsi->nrequests && |
| NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) |
| inode->i_version++; |
| /* |
| * Swap-space should not get truncated. Hence no need to plug the race |
| * with invalidate/truncate. |
| */ |
| if (likely(!PageSwapCache(req->wb_page))) { |
| set_bit(PG_MAPPED, &req->wb_flags); |
| SetPagePrivate(req->wb_page); |
| set_page_private(req->wb_page, (unsigned long)req); |
| } |
| nfsi->nrequests++; |
| /* this a head request for a page group - mark it as having an |
| * extra reference so sub groups can follow suit. |
| * This flag also informs pgio layer when to bump nrequests when |
| * adding subrequests. */ |
| WARN_ON(test_and_set_bit(PG_INODE_REF, &req->wb_flags)); |
| kref_get(&req->wb_kref); |
| spin_unlock(&inode->i_lock); |
| } |
| |
| /* |
| * Remove a write request from an inode |
| */ |
| static void nfs_inode_remove_request(struct nfs_page *req) |
| { |
| struct inode *inode = d_inode(req->wb_context->dentry); |
| struct nfs_inode *nfsi = NFS_I(inode); |
| struct nfs_page *head; |
| |
| if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) { |
| head = req->wb_head; |
| |
| spin_lock(&inode->i_lock); |
| if (likely(!PageSwapCache(head->wb_page))) { |
| set_page_private(head->wb_page, 0); |
| ClearPagePrivate(head->wb_page); |
| smp_mb__after_atomic(); |
| wake_up_page(head->wb_page, PG_private); |
| clear_bit(PG_MAPPED, &head->wb_flags); |
| } |
| nfsi->nrequests--; |
| spin_unlock(&inode->i_lock); |
| } else { |
| spin_lock(&inode->i_lock); |
| nfsi->nrequests--; |
| spin_unlock(&inode->i_lock); |
| } |
| |
| if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) |
| nfs_release_request(req); |
| } |
| |
| static void |
| nfs_mark_request_dirty(struct nfs_page *req) |
| { |
| __set_page_dirty_nobuffers(req->wb_page); |
| } |
| |
| /* |
| * nfs_page_search_commits_for_head_request_locked |
| * |
| * Search through commit lists on @inode for the head request for @page. |
| * Must be called while holding the inode (which is cinfo) lock. |
| * |
| * Returns the head request if found, or NULL if not found. |
| */ |
| static struct nfs_page * |
| nfs_page_search_commits_for_head_request_locked(struct nfs_inode *nfsi, |
| struct page *page) |
| { |
| struct nfs_page *freq, *t; |
| struct nfs_commit_info cinfo; |
| struct inode *inode = &nfsi->vfs_inode; |
| |
| nfs_init_cinfo_from_inode(&cinfo, inode); |
| |
| /* search through pnfs commit lists */ |
| freq = pnfs_search_commit_reqs(inode, &cinfo, page); |
| if (freq) |
| return freq->wb_head; |
| |
| /* Linearly search the commit list for the correct request */ |
| list_for_each_entry_safe(freq, t, &cinfo.mds->list, wb_list) { |
| if (freq->wb_page == page) |
| return freq->wb_head; |
| } |
| |
| return NULL; |
| } |
| |
| /** |
| * nfs_request_add_commit_list_locked - add request to a commit list |
| * @req: pointer to a struct nfs_page |
| * @dst: commit list head |
| * @cinfo: holds list lock and accounting info |
| * |
| * This sets the PG_CLEAN bit, updates the cinfo count of |
| * number of outstanding requests requiring a commit as well as |
| * the MM page stats. |
| * |
| * The caller must hold the cinfo->lock, and the nfs_page lock. |
| */ |
| void |
| nfs_request_add_commit_list_locked(struct nfs_page *req, struct list_head *dst, |
| struct nfs_commit_info *cinfo) |
| { |
| set_bit(PG_CLEAN, &req->wb_flags); |
| nfs_list_add_request(req, dst); |
| cinfo->mds->ncommit++; |
| } |
| EXPORT_SYMBOL_GPL(nfs_request_add_commit_list_locked); |
| |
| /** |
| * nfs_request_add_commit_list - add request to a commit list |
| * @req: pointer to a struct nfs_page |
| * @dst: commit list head |
| * @cinfo: holds list lock and accounting info |
| * |
| * This sets the PG_CLEAN bit, updates the cinfo count of |
| * number of outstanding requests requiring a commit as well as |
| * the MM page stats. |
| * |
| * The caller must _not_ hold the cinfo->lock, but must be |
| * holding the nfs_page lock. |
| */ |
| void |
| nfs_request_add_commit_list(struct nfs_page *req, struct list_head *dst, |
| struct nfs_commit_info *cinfo) |
| { |
| spin_lock(cinfo->lock); |
| nfs_request_add_commit_list_locked(req, dst, cinfo); |
| spin_unlock(cinfo->lock); |
| nfs_mark_page_unstable(req->wb_page, cinfo); |
| } |
| EXPORT_SYMBOL_GPL(nfs_request_add_commit_list); |
| |
| /** |
| * nfs_request_remove_commit_list - Remove request from a commit list |
| * @req: pointer to a nfs_page |
| * @cinfo: holds list lock and accounting info |
| * |
| * This clears the PG_CLEAN bit, and updates the cinfo's count of |
| * number of outstanding requests requiring a commit |
| * It does not update the MM page stats. |
| * |
| * The caller _must_ hold the cinfo->lock and the nfs_page lock. |
| */ |
| void |
| nfs_request_remove_commit_list(struct nfs_page *req, |
| struct nfs_commit_info *cinfo) |
| { |
| if (!test_and_clear_bit(PG_CLEAN, &(req)->wb_flags)) |
| return; |
| nfs_list_remove_request(req); |
| cinfo->mds->ncommit--; |
| } |
| EXPORT_SYMBOL_GPL(nfs_request_remove_commit_list); |
| |
| static void nfs_init_cinfo_from_inode(struct nfs_commit_info *cinfo, |
| struct inode *inode) |
| { |
| cinfo->lock = &inode->i_lock; |
| cinfo->mds = &NFS_I(inode)->commit_info; |
| cinfo->ds = pnfs_get_ds_info(inode); |
| cinfo->dreq = NULL; |
| cinfo->completion_ops = &nfs_commit_completion_ops; |
| } |
| |
| void nfs_init_cinfo(struct nfs_commit_info *cinfo, |
| struct inode *inode, |
| struct nfs_direct_req *dreq) |
| { |
| if (dreq) |
| nfs_init_cinfo_from_dreq(cinfo, dreq); |
| else |
| nfs_init_cinfo_from_inode(cinfo, inode); |
| } |
| EXPORT_SYMBOL_GPL(nfs_init_cinfo); |
| |
| /* |
| * Add a request to the inode's commit list. |
| */ |
| void |
| nfs_mark_request_commit(struct nfs_page *req, struct pnfs_layout_segment *lseg, |
| struct nfs_commit_info *cinfo, u32 ds_commit_idx) |
| { |
| if (pnfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx)) |
| return; |
| nfs_request_add_commit_list(req, &cinfo->mds->list, cinfo); |
| } |
| |
| static void |
| nfs_clear_page_commit(struct page *page) |
| { |
| dec_zone_page_state(page, NR_UNSTABLE_NFS); |
| dec_wb_stat(&inode_to_bdi(page_file_mapping(page)->host)->wb, |
| WB_RECLAIMABLE); |
| } |
| |
| /* Called holding inode (/cinfo) lock */ |
| static void |
| nfs_clear_request_commit(struct nfs_page *req) |
| { |
| if (test_bit(PG_CLEAN, &req->wb_flags)) { |
| struct inode *inode = d_inode(req->wb_context->dentry); |
| struct nfs_commit_info cinfo; |
| |
| nfs_init_cinfo_from_inode(&cinfo, inode); |
| if (!pnfs_clear_request_commit(req, &cinfo)) { |
| nfs_request_remove_commit_list(req, &cinfo); |
| } |
| nfs_clear_page_commit(req->wb_page); |
| } |
| } |
| |
| int nfs_write_need_commit(struct nfs_pgio_header *hdr) |
| { |
| if (hdr->verf.committed == NFS_DATA_SYNC) |
| return hdr->lseg == NULL; |
| return hdr->verf.committed != NFS_FILE_SYNC; |
| } |
| |
| static void nfs_write_completion(struct nfs_pgio_header *hdr) |
| { |
| struct nfs_commit_info cinfo; |
| unsigned long bytes = 0; |
| |
| if (test_bit(NFS_IOHDR_REDO, &hdr->flags)) |
| goto out; |
| nfs_init_cinfo_from_inode(&cinfo, hdr->inode); |
| while (!list_empty(&hdr->pages)) { |
| struct nfs_page *req = nfs_list_entry(hdr->pages.next); |
| |
| bytes += req->wb_bytes; |
| nfs_list_remove_request(req); |
| if (test_bit(NFS_IOHDR_ERROR, &hdr->flags) && |
| (hdr->good_bytes < bytes)) { |
| nfs_set_pageerror(req->wb_page); |
| nfs_context_set_write_error(req->wb_context, hdr->error); |
| goto remove_req; |
| } |
| if (nfs_write_need_commit(hdr)) { |
| memcpy(&req->wb_verf, &hdr->verf.verifier, sizeof(req->wb_verf)); |
| nfs_mark_request_commit(req, hdr->lseg, &cinfo, |
| hdr->pgio_mirror_idx); |
| goto next; |
| } |
| remove_req: |
| nfs_inode_remove_request(req); |
| next: |
| nfs_unlock_request(req); |
| nfs_end_page_writeback(req); |
| nfs_release_request(req); |
| } |
| out: |
| hdr->release(hdr); |
| } |
| |
| unsigned long |
| nfs_reqs_to_commit(struct nfs_commit_info *cinfo) |
| { |
| return cinfo->mds->ncommit; |
| } |
| |
| /* cinfo->lock held by caller */ |
| int |
| nfs_scan_commit_list(struct list_head *src, struct list_head *dst, |
| struct nfs_commit_info *cinfo, int max) |
| { |
| struct nfs_page *req, *tmp; |
| int ret = 0; |
| |
| list_for_each_entry_safe(req, tmp, src, wb_list) { |
| if (!nfs_lock_request(req)) |
| continue; |
| kref_get(&req->wb_kref); |
| if (cond_resched_lock(cinfo->lock)) |
| list_safe_reset_next(req, tmp, wb_list); |
| nfs_request_remove_commit_list(req, cinfo); |
| nfs_list_add_request(req, dst); |
| ret++; |
| if ((ret == max) && !cinfo->dreq) |
| break; |
| } |
| return ret; |
| } |
| |
| /* |
| * nfs_scan_commit - Scan an inode for commit requests |
| * @inode: NFS inode to scan |
| * @dst: mds destination list |
| * @cinfo: mds and ds lists of reqs ready to commit |
| * |
| * Moves requests from the inode's 'commit' request list. |
| * The requests are *not* checked to ensure that they form a contiguous set. |
| */ |
| int |
| nfs_scan_commit(struct inode *inode, struct list_head *dst, |
| struct nfs_commit_info *cinfo) |
| { |
| int ret = 0; |
| |
| spin_lock(cinfo->lock); |
| if (cinfo->mds->ncommit > 0) { |
| const int max = INT_MAX; |
| |
| ret = nfs_scan_commit_list(&cinfo->mds->list, dst, |
| cinfo, max); |
| ret += pnfs_scan_commit_lists(inode, cinfo, max - ret); |
| } |
| spin_unlock(cinfo->lock); |
| return ret; |
| } |
| |
| /* |
| * 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_head_request_locked(NFS_I(inode), page); |
| if (req == NULL) |
| goto out_unlock; |
| |
| /* should be handled by nfs_flush_incompatible */ |
| WARN_ON_ONCE(req->wb_head != req); |
| WARN_ON_ONCE(req->wb_this_page != req); |
| |
| 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_lock_request(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); |
| } |
| |
| /* 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: |
| if (req) |
| nfs_clear_request_commit(req); |
| 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_file_mapping(page)->host; |
| struct nfs_page *req; |
| |
| req = nfs_try_to_update_request(inode, page, offset, bytes); |
| if (req != NULL) |
| goto out; |
| req = nfs_create_request(ctx, page, NULL, offset, bytes); |
| if (IS_ERR(req)) |
| goto out; |
| nfs_inode_add_request(inode, req); |
| 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); |
| /* Update file length */ |
| nfs_grow_file(page, offset, count); |
| nfs_mark_uptodate(req); |
| nfs_mark_request_dirty(req); |
| nfs_unlock_and_release_request(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_lock_context *l_ctx; |
| struct file_lock_context *flctx = file_inode(file)->i_flctx; |
| 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_head_request(page); |
| if (req == NULL) |
| return 0; |
| l_ctx = req->wb_lock_context; |
| do_flush = req->wb_page != page || req->wb_context != ctx; |
| /* for now, flush if more than 1 request in page_group */ |
| do_flush |= req->wb_this_page != req; |
| if (l_ctx && flctx && |
| !(list_empty_careful(&flctx->flc_posix) && |
| list_empty_careful(&flctx->flc_flock))) { |
| do_flush |= l_ctx->lockowner.l_owner != current->files |
| || l_ctx->lockowner.l_pid != current->tgid; |
| } |
| nfs_release_request(req); |
| if (!do_flush) |
| return 0; |
| status = nfs_wb_page(page_file_mapping(page)->host, page); |
| } while (status == 0); |
| return status; |
| } |
| |
| /* |
| * Avoid buffered writes when a open context credential's key would |
| * expire soon. |
| * |
| * Returns -EACCES if the key will expire within RPC_KEY_EXPIRE_FAIL. |
| * |
| * Return 0 and set a credential flag which triggers the inode to flush |
| * and performs NFS_FILE_SYNC writes if the key will expired within |
| * RPC_KEY_EXPIRE_TIMEO. |
| */ |
| int |
| nfs_key_timeout_notify(struct file *filp, struct inode *inode) |
| { |
| struct nfs_open_context *ctx = nfs_file_open_context(filp); |
| struct rpc_auth *auth = NFS_SERVER(inode)->client->cl_auth; |
| |
| return rpcauth_key_timeout_notify(auth, ctx->cred); |
| } |
| |
| /* |
| * Test if the open context credential key is marked to expire soon. |
| */ |
| bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx) |
| { |
| return rpcauth_cred_key_to_expire(ctx->cred); |
| } |
| |
| /* |
| * 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 bool nfs_write_pageuptodate(struct page *page, struct inode *inode) |
| { |
| struct nfs_inode *nfsi = NFS_I(inode); |
| |
| if (nfs_have_delegated_attributes(inode)) |
| goto out; |
| if (nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE) |
| return false; |
| smp_rmb(); |
| if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags)) |
| return false; |
| out: |
| if (nfsi->cache_validity & NFS_INO_INVALID_DATA) |
| return false; |
| return PageUptodate(page) != 0; |
| } |
| |
| static bool |
| is_whole_file_wrlock(struct file_lock *fl) |
| { |
| return fl->fl_start == 0 && fl->fl_end == OFFSET_MAX && |
| fl->fl_type == F_WRLCK; |
| } |
| |
| /* If we know the page is up to date, and we're not using byte range locks (or |
| * if we have the whole file locked for writing), it may be more efficient to |
| * extend the write to cover the entire page in order to avoid fragmentation |
| * inefficiencies. |
| * |
| * If the file is opened for synchronous writes then we can just skip the rest |
| * of the checks. |
| */ |
| static int nfs_can_extend_write(struct file *file, struct page *page, struct inode *inode) |
| { |
| int ret; |
| struct file_lock_context *flctx = inode->i_flctx; |
| struct file_lock *fl; |
| |
| if (file->f_flags & O_DSYNC) |
| return 0; |
| if (!nfs_write_pageuptodate(page, inode)) |
| return 0; |
| if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE)) |
| return 1; |
| if (!flctx || (list_empty_careful(&flctx->flc_flock) && |
| list_empty_careful(&flctx->flc_posix))) |
| return 1; |
| |
| /* Check to see if there are whole file write locks */ |
| ret = 0; |
| spin_lock(&flctx->flc_lock); |
| if (!list_empty(&flctx->flc_posix)) { |
| fl = list_first_entry(&flctx->flc_posix, struct file_lock, |
| fl_list); |
| if (is_whole_file_wrlock(fl)) |
| ret = 1; |
| } else if (!list_empty(&flctx->flc_flock)) { |
| fl = list_first_entry(&flctx->flc_flock, struct file_lock, |
| fl_list); |
| if (fl->fl_type == F_WRLCK) |
| ret = 1; |
| } |
| spin_unlock(&flctx->flc_lock); |
| return ret; |
| } |
| |
| /* |
| * 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_file_mapping(page)->host; |
| int status = 0; |
| |
| nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE); |
| |
| dprintk("NFS: nfs_updatepage(%pD2 %d@%lld)\n", |
| file, count, (long long)(page_file_offset(page) + offset)); |
| |
| if (nfs_can_extend_write(file, page, inode)) { |
| 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); |
| else |
| __set_page_dirty_nobuffers(page); |
| |
| dprintk("NFS: nfs_updatepage returns %d (isize %lld)\n", |
| status, (long long)i_size_read(inode)); |
| return status; |
| } |
| |
| 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 void nfs_initiate_write(struct nfs_pgio_header *hdr, |
| struct rpc_message *msg, |
| const struct nfs_rpc_ops *rpc_ops, |
| struct rpc_task_setup *task_setup_data, int how) |
| { |
| int priority = flush_task_priority(how); |
| |
| task_setup_data->priority = priority; |
| rpc_ops->write_setup(hdr, msg); |
| |
| nfs4_state_protect_write(NFS_SERVER(hdr->inode)->nfs_client, |
| &task_setup_data->rpc_client, msg, hdr); |
| } |
| |
| /* 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) |
| { |
| nfs_mark_request_dirty(req); |
| set_bit(NFS_CONTEXT_RESEND_WRITES, &req->wb_context->flags); |
| nfs_unlock_request(req); |
| nfs_end_page_writeback(req); |
| nfs_release_request(req); |
| } |
| |
| static void nfs_async_write_error(struct list_head *head) |
| { |
| struct nfs_page *req; |
| |
| while (!list_empty(head)) { |
| req = nfs_list_entry(head->next); |
| nfs_list_remove_request(req); |
| nfs_redirty_request(req); |
| } |
| } |
| |
| static const struct nfs_pgio_completion_ops nfs_async_write_completion_ops = { |
| .error_cleanup = nfs_async_write_error, |
| .completion = nfs_write_completion, |
| }; |
| |
| void nfs_pageio_init_write(struct nfs_pageio_descriptor *pgio, |
| struct inode *inode, int ioflags, bool force_mds, |
| const struct nfs_pgio_completion_ops *compl_ops) |
| { |
| struct nfs_server *server = NFS_SERVER(inode); |
| const struct nfs_pageio_ops *pg_ops = &nfs_pgio_rw_ops; |
| |
| #ifdef CONFIG_NFS_V4_1 |
| if (server->pnfs_curr_ld && !force_mds) |
| pg_ops = server->pnfs_curr_ld->pg_write_ops; |
| #endif |
| nfs_pageio_init(pgio, inode, pg_ops, compl_ops, &nfs_rw_write_ops, |
| server->wsize, ioflags); |
| } |
| EXPORT_SYMBOL_GPL(nfs_pageio_init_write); |
| |
| void nfs_pageio_reset_write_mds(struct nfs_pageio_descriptor *pgio) |
| { |
| struct nfs_pgio_mirror *mirror; |
| |
| if (pgio->pg_ops && pgio->pg_ops->pg_cleanup) |
| pgio->pg_ops->pg_cleanup(pgio); |
| |
| pgio->pg_ops = &nfs_pgio_rw_ops; |
| |
| nfs_pageio_stop_mirroring(pgio); |
| |
| mirror = &pgio->pg_mirrors[0]; |
| mirror->pg_bsize = NFS_SERVER(pgio->pg_inode)->wsize; |
| } |
| EXPORT_SYMBOL_GPL(nfs_pageio_reset_write_mds); |
| |
| |
| void nfs_commit_prepare(struct rpc_task *task, void *calldata) |
| { |
| struct nfs_commit_data *data = calldata; |
| |
| NFS_PROTO(data->inode)->commit_rpc_prepare(task, data); |
| } |
| |
| /* |
| * Special version of should_remove_suid() that ignores capabilities. |
| */ |
| static int nfs_should_remove_suid(const struct inode *inode) |
| { |
| umode_t mode = inode->i_mode; |
| int kill = 0; |
| |
| /* suid always must be killed */ |
| if (unlikely(mode & S_ISUID)) |
| kill = ATTR_KILL_SUID; |
| |
| /* |
| * sgid without any exec bits is just a mandatory locking mark; leave |
| * it alone. If some exec bits are set, it's a real sgid; kill it. |
| */ |
| if (unlikely((mode & S_ISGID) && (mode & S_IXGRP))) |
| kill |= ATTR_KILL_SGID; |
| |
| if (unlikely(kill && S_ISREG(mode))) |
| return kill; |
| |
| return 0; |
| } |
| |
| static void nfs_writeback_check_extend(struct nfs_pgio_header *hdr, |
| struct nfs_fattr *fattr) |
| { |
| struct nfs_pgio_args *argp = &hdr->args; |
| struct nfs_pgio_res *resp = &hdr->res; |
| u64 size = argp->offset + resp->count; |
| |
| if (!(fattr->valid & NFS_ATTR_FATTR_SIZE)) |
| fattr->size = size; |
| if (nfs_size_to_loff_t(fattr->size) < i_size_read(hdr->inode)) { |
| fattr->valid &= ~NFS_ATTR_FATTR_SIZE; |
| return; |
| } |
| if (size != fattr->size) |
| return; |
| /* Set attribute barrier */ |
| nfs_fattr_set_barrier(fattr); |
| /* ...and update size */ |
| fattr->valid |= NFS_ATTR_FATTR_SIZE; |
| } |
| |
| void nfs_writeback_update_inode(struct nfs_pgio_header *hdr) |
| { |
| struct nfs_fattr *fattr = &hdr->fattr; |
| struct inode *inode = hdr->inode; |
| |
| spin_lock(&inode->i_lock); |
| nfs_writeback_check_extend(hdr, fattr); |
| nfs_post_op_update_inode_force_wcc_locked(inode, fattr); |
| spin_unlock(&inode->i_lock); |
| } |
| EXPORT_SYMBOL_GPL(nfs_writeback_update_inode); |
| |
| /* |
| * This function is called when the WRITE call is complete. |
| */ |
| static int nfs_writeback_done(struct rpc_task *task, |
| struct nfs_pgio_header *hdr, |
| struct inode *inode) |
| { |
| int 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(inode)->write_done(task, hdr); |
| if (status != 0) |
| return status; |
| nfs_add_stats(inode, NFSIOS_SERVERWRITTENBYTES, hdr->res.count); |
| |
| if (hdr->res.verf->committed < hdr->args.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; |
| |
| /* Note this will print the MDS for a DS write */ |
| if (time_before(complain, jiffies)) { |
| dprintk("NFS: faulty NFS server %s:" |
| " (committed = %d) != (stable = %d)\n", |
| NFS_SERVER(inode)->nfs_client->cl_hostname, |
| hdr->res.verf->committed, hdr->args.stable); |
| complain = jiffies + 300 * HZ; |
| } |
| } |
| |
| /* Deal with the suid/sgid bit corner case */ |
| if (nfs_should_remove_suid(inode)) |
| nfs_mark_for_revalidate(inode); |
| return 0; |
| } |
| |
| /* |
| * This function is called when the WRITE call is complete. |
| */ |
| static void nfs_writeback_result(struct rpc_task *task, |
| struct nfs_pgio_header *hdr) |
| { |
| struct nfs_pgio_args *argp = &hdr->args; |
| struct nfs_pgio_res *resp = &hdr->res; |
| |
| if (resp->count < argp->count) { |
| static unsigned long complain; |
| |
| /* This a short write! */ |
| nfs_inc_stats(hdr->inode, NFSIOS_SHORTWRITE); |
| |
| /* Has the server at least made some progress? */ |
| if (resp->count == 0) { |
| if (time_before(complain, jiffies)) { |
| printk(KERN_WARNING |
| "NFS: Server wrote zero bytes, expected %u.\n", |
| argp->count); |
| complain = jiffies + 300 * HZ; |
| } |
| nfs_set_pgio_error(hdr, -EIO, argp->offset); |
| task->tk_status = -EIO; |
| return; |
| } |
| /* Was this an NFSv2 write or an NFSv3 stable write? */ |
| if (resp->verf->committed != NFS_UNSTABLE) { |
| /* Resend from where the server left off */ |
| hdr->mds_offset += resp->count; |
| 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; |
| } |
| rpc_restart_call_prepare(task); |
| } |
| } |
| |
| |
| static int nfs_commit_set_lock(struct nfs_inode *nfsi, int may_wait) |
| { |
| int ret; |
| |
| if (!test_and_set_bit(NFS_INO_COMMIT, &nfsi->flags)) |
| return 1; |
| if (!may_wait) |
| return 0; |
| ret = out_of_line_wait_on_bit_lock(&nfsi->flags, |
| NFS_INO_COMMIT, |
| nfs_wait_bit_killable, |
| TASK_KILLABLE); |
| return (ret < 0) ? ret : 1; |
| } |
| |
| static void nfs_commit_clear_lock(struct nfs_inode *nfsi) |
| { |
| clear_bit(NFS_INO_COMMIT, &nfsi->flags); |
| smp_mb__after_atomic(); |
| wake_up_bit(&nfsi->flags, NFS_INO_COMMIT); |
| } |
| |
| void nfs_commitdata_release(struct nfs_commit_data *data) |
| { |
| put_nfs_open_context(data->context); |
| nfs_commit_free(data); |
| } |
| EXPORT_SYMBOL_GPL(nfs_commitdata_release); |
| |
| int nfs_initiate_commit(struct rpc_clnt *clnt, struct nfs_commit_data *data, |
| const struct nfs_rpc_ops *nfs_ops, |
| const struct rpc_call_ops *call_ops, |
| int how, int flags) |
| { |
| struct rpc_task *task; |
| int priority = flush_task_priority(how); |
| struct rpc_message msg = { |
| .rpc_argp = &data->args, |
| .rpc_resp = &data->res, |
| .rpc_cred = data->cred, |
| }; |
| struct rpc_task_setup task_setup_data = { |
| .task = &data->task, |
| .rpc_client = clnt, |
| .rpc_message = &msg, |
| .callback_ops = call_ops, |
| .callback_data = data, |
| .workqueue = nfsiod_workqueue, |
| .flags = RPC_TASK_ASYNC | flags, |
| .priority = priority, |
| }; |
| /* Set up the initial task struct. */ |
| nfs_ops->commit_setup(data, &msg); |
| |
| dprintk("NFS: initiated commit call\n"); |
| |
| nfs4_state_protect(NFS_SERVER(data->inode)->nfs_client, |
| NFS_SP4_MACH_CRED_COMMIT, &task_setup_data.rpc_client, &msg); |
| |
| 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; |
| } |
| EXPORT_SYMBOL_GPL(nfs_initiate_commit); |
| |
| static loff_t nfs_get_lwb(struct list_head *head) |
| { |
| loff_t lwb = 0; |
| struct nfs_page *req; |
| |
| list_for_each_entry(req, head, wb_list) |
| if (lwb < (req_offset(req) + req->wb_bytes)) |
| lwb = req_offset(req) + req->wb_bytes; |
| |
| return lwb; |
| } |
| |
| /* |
| * Set up the argument/result storage required for the RPC call. |
| */ |
| void nfs_init_commit(struct nfs_commit_data *data, |
| struct list_head *head, |
| struct pnfs_layout_segment *lseg, |
| struct nfs_commit_info *cinfo) |
| { |
| struct nfs_page *first = nfs_list_entry(head->next); |
| struct inode *inode = d_inode(first->wb_context->dentry); |
| |
| /* 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 = first->wb_context->cred; |
| data->lseg = lseg; /* reference transferred */ |
| /* only set lwb for pnfs commit */ |
| if (lseg) |
| data->lwb = nfs_get_lwb(&data->pages); |
| data->mds_ops = &nfs_commit_ops; |
| data->completion_ops = cinfo->completion_ops; |
| data->dreq = cinfo->dreq; |
| |
| 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->context = get_nfs_open_context(first->wb_context); |
| data->res.fattr = &data->fattr; |
| data->res.verf = &data->verf; |
| nfs_fattr_init(&data->fattr); |
| } |
| EXPORT_SYMBOL_GPL(nfs_init_commit); |
| |
| void nfs_retry_commit(struct list_head *page_list, |
| struct pnfs_layout_segment *lseg, |
| struct nfs_commit_info *cinfo, |
| u32 ds_commit_idx) |
| { |
| struct nfs_page *req; |
| |
| while (!list_empty(page_list)) { |
| req = nfs_list_entry(page_list->next); |
| nfs_list_remove_request(req); |
| nfs_mark_request_commit(req, lseg, cinfo, ds_commit_idx); |
| if (!cinfo->dreq) |
| nfs_clear_page_commit(req->wb_page); |
| nfs_unlock_and_release_request(req); |
| } |
| } |
| EXPORT_SYMBOL_GPL(nfs_retry_commit); |
| |
| /* |
| * Commit dirty pages |
| */ |
| static int |
| nfs_commit_list(struct inode *inode, struct list_head *head, int how, |
| struct nfs_commit_info *cinfo) |
| { |
| struct nfs_commit_data *data; |
| |
| data = nfs_commitdata_alloc(); |
| |
| if (!data) |
| goto out_bad; |
| |
| /* Set up the argument struct */ |
| nfs_init_commit(data, head, NULL, cinfo); |
| atomic_inc(&cinfo->mds->rpcs_out); |
| return nfs_initiate_commit(NFS_CLIENT(inode), data, NFS_PROTO(inode), |
| data->mds_ops, how, 0); |
| out_bad: |
| nfs_retry_commit(head, NULL, cinfo, 0); |
| cinfo->completion_ops->error_cleanup(NFS_I(inode)); |
| return -ENOMEM; |
| } |
| |
| /* |
| * COMMIT call returned |
| */ |
| static void nfs_commit_done(struct rpc_task *task, void *calldata) |
| { |
| struct nfs_commit_data *data = calldata; |
| |
| dprintk("NFS: %5u nfs_commit_done (status %d)\n", |
| task->tk_pid, task->tk_status); |
| |
| /* Call the NFS version-specific code */ |
| NFS_PROTO(data->inode)->commit_done(task, data); |
| } |
| |
| static void nfs_commit_release_pages(struct nfs_commit_data *data) |
| { |
| struct nfs_page *req; |
| int status = data->task.tk_status; |
| struct nfs_commit_info cinfo; |
| struct nfs_server *nfss; |
| |
| while (!list_empty(&data->pages)) { |
| req = nfs_list_entry(data->pages.next); |
| nfs_list_remove_request(req); |
| nfs_clear_page_commit(req->wb_page); |
| |
| dprintk("NFS: commit (%s/%llu %d@%lld)", |
| req->wb_context->dentry->d_sb->s_id, |
| (unsigned long long)NFS_FILEID(d_inode(req->wb_context->dentry)), |
| 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, &data->verf.verifier, sizeof(req->wb_verf))) { |
| /* 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); |
| set_bit(NFS_CONTEXT_RESEND_WRITES, &req->wb_context->flags); |
| next: |
| nfs_unlock_and_release_request(req); |
| } |
| nfss = NFS_SERVER(data->inode); |
| if (atomic_long_read(&nfss->writeback) < NFS_CONGESTION_OFF_THRESH) |
| clear_bdi_congested(&nfss->backing_dev_info, BLK_RW_ASYNC); |
| |
| nfs_init_cinfo(&cinfo, data->inode, data->dreq); |
| if (atomic_dec_and_test(&cinfo.mds->rpcs_out)) |
| nfs_commit_clear_lock(NFS_I(data->inode)); |
| } |
| |
| static void nfs_commit_release(void *calldata) |
| { |
| struct nfs_commit_data *data = calldata; |
| |
| data->completion_ops->completion(data); |
| nfs_commitdata_release(calldata); |
| } |
| |
| static const struct rpc_call_ops nfs_commit_ops = { |
| .rpc_call_prepare = nfs_commit_prepare, |
| .rpc_call_done = nfs_commit_done, |
| .rpc_release = nfs_commit_release, |
| }; |
| |
| static const struct nfs_commit_completion_ops nfs_commit_completion_ops = { |
| .completion = nfs_commit_release_pages, |
| .error_cleanup = nfs_commit_clear_lock, |
| }; |
| |
| int nfs_generic_commit_list(struct inode *inode, struct list_head *head, |
| int how, struct nfs_commit_info *cinfo) |
| { |
| int status; |
| |
| status = pnfs_commit_list(inode, head, how, cinfo); |
| if (status == PNFS_NOT_ATTEMPTED) |
| status = nfs_commit_list(inode, head, how, cinfo); |
| return status; |
| } |
| |
| int nfs_commit_inode(struct inode *inode, int how) |
| { |
| LIST_HEAD(head); |
| struct nfs_commit_info cinfo; |
| int may_wait = how & FLUSH_SYNC; |
| int res; |
| |
| res = nfs_commit_set_lock(NFS_I(inode), may_wait); |
| if (res <= 0) |
| goto out_mark_dirty; |
| nfs_init_cinfo_from_inode(&cinfo, inode); |
| res = nfs_scan_commit(inode, &head, &cinfo); |
| if (res) { |
| int error; |
| |
| error = nfs_generic_commit_list(inode, &head, how, &cinfo); |
| if (error < 0) |
| return error; |
| if (!may_wait) |
| goto out_mark_dirty; |
| error = wait_on_bit_action(&NFS_I(inode)->flags, |
| NFS_INO_COMMIT, |
| nfs_wait_bit_killable, |
| TASK_KILLABLE); |
| if (error < 0) |
| return error; |
| } 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; |
| } |
| |
| int nfs_write_inode(struct inode *inode, struct writeback_control *wbc) |
| { |
| struct nfs_inode *nfsi = NFS_I(inode); |
| int flags = FLUSH_SYNC; |
| int ret = 0; |
| |
| /* no commits means nothing needs to be done */ |
| if (!nfsi->commit_info.ncommit) |
| return ret; |
| |
| 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->commit_info.ncommit <= (nfsi->nrequests >> 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; |
| } |
| EXPORT_SYMBOL_GPL(nfs_write_inode); |
| |
| /* |
| * flush the inode to disk. |
| */ |
| int nfs_wb_all(struct inode *inode) |
| { |
| int ret; |
| |
| trace_nfs_writeback_inode_enter(inode); |
| |
| ret = filemap_write_and_wait(inode->i_mapping); |
| if (ret) |
| goto out; |
| ret = nfs_commit_inode(inode, FLUSH_SYNC); |
| if (ret < 0) |
| goto out; |
| pnfs_sync_inode(inode, true); |
| ret = 0; |
| |
| out: |
| trace_nfs_writeback_inode_exit(inode, ret); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(nfs_wb_all); |
| |
| int nfs_wb_page_cancel(struct inode *inode, struct page *page) |
| { |
| struct nfs_page *req; |
| int ret = 0; |
| |
| wait_on_page_writeback(page); |
| |
| /* blocking call to cancel all requests and join to a single (head) |
| * request */ |
| req = nfs_lock_and_join_requests(page, false); |
| |
| if (IS_ERR(req)) { |
| ret = PTR_ERR(req); |
| } else if (req) { |
| /* all requests from this page have been cancelled by |
| * nfs_lock_and_join_requests, so just remove the head |
| * request from the inode / page_private pointer and |
| * release it */ |
| nfs_inode_remove_request(req); |
| nfs_unlock_and_release_request(req); |
| } |
| |
| 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_file_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; |
| |
| trace_nfs_writeback_page_enter(inode); |
| |
| 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; |
| } |
| ret = 0; |
| if (!PagePrivate(page)) |
| break; |
| ret = nfs_commit_inode(inode, FLUSH_SYNC); |
| if (ret < 0) |
| goto out_error; |
| } |
| out_error: |
| trace_nfs_writeback_page_exit(inode, ret); |
| return ret; |
| } |
| |
| #ifdef CONFIG_MIGRATION |
| int nfs_migrate_page(struct address_space *mapping, struct page *newpage, |
| struct page *page, enum migrate_mode mode) |
| { |
| /* |
| * If PagePrivate is set, then the page is currently associated with |
| * an in-progress read or write request. Don't try to migrate it. |
| * |
| * FIXME: we could do this in principle, but we'll need a way to ensure |
| * that we can safely release the inode reference while holding |
| * the page lock. |
| */ |
| if (PagePrivate(page)) |
| return -EBUSY; |
| |
| if (!nfs_fscache_release_page(page, GFP_KERNEL)) |
| return -EBUSY; |
| |
| return migrate_page(mapping, newpage, page, mode); |
| } |
| #endif |
| |
| int __init nfs_init_writepagecache(void) |
| { |
| nfs_wdata_cachep = kmem_cache_create("nfs_write_data", |
| sizeof(struct nfs_pgio_header), |
| 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) |
| goto out_destroy_write_cache; |
| |
| nfs_cdata_cachep = kmem_cache_create("nfs_commit_data", |
| sizeof(struct nfs_commit_data), |
| 0, SLAB_HWCACHE_ALIGN, |
| NULL); |
| if (nfs_cdata_cachep == NULL) |
| goto out_destroy_write_mempool; |
| |
| nfs_commit_mempool = mempool_create_slab_pool(MIN_POOL_COMMIT, |
| nfs_cdata_cachep); |
| if (nfs_commit_mempool == NULL) |
| goto out_destroy_commit_cache; |
| |
| /* |
| * 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; |
| |
| out_destroy_commit_cache: |
| kmem_cache_destroy(nfs_cdata_cachep); |
| out_destroy_write_mempool: |
| mempool_destroy(nfs_wdata_mempool); |
| out_destroy_write_cache: |
| kmem_cache_destroy(nfs_wdata_cachep); |
| return -ENOMEM; |
| } |
| |
| void nfs_destroy_writepagecache(void) |
| { |
| mempool_destroy(nfs_commit_mempool); |
| kmem_cache_destroy(nfs_cdata_cachep); |
| mempool_destroy(nfs_wdata_mempool); |
| kmem_cache_destroy(nfs_wdata_cachep); |
| } |
| |
| static const struct nfs_rw_ops nfs_rw_write_ops = { |
| .rw_mode = FMODE_WRITE, |
| .rw_alloc_header = nfs_writehdr_alloc, |
| .rw_free_header = nfs_writehdr_free, |
| .rw_done = nfs_writeback_done, |
| .rw_result = nfs_writeback_result, |
| .rw_initiate = nfs_initiate_write, |
| }; |