diff options
-rw-r--r-- | fs/cifs/file.c | 241 |
1 files changed, 99 insertions, 142 deletions
diff --git a/fs/cifs/file.c b/fs/cifs/file.c index c672afef0c0..00b926ce793 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -1092,58 +1092,20 @@ static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to) static int cifs_writepages(struct address_space *mapping, struct writeback_control *wbc) { - unsigned int bytes_to_write; - unsigned int bytes_written; - struct cifs_sb_info *cifs_sb; - int done = 0; - pgoff_t end; - pgoff_t index; - int range_whole = 0; - struct kvec *iov; - int len; - int n_iov = 0; - pgoff_t next; - int nr_pages; - __u64 offset = 0; - struct cifsFileInfo *open_file; - struct cifsTconInfo *tcon; - struct cifsInodeInfo *cifsi = CIFS_I(mapping->host); + struct cifs_sb_info *cifs_sb = CIFS_SB(mapping->host->i_sb); + bool done = false, scanned = false, range_whole = false; + pgoff_t end, index; + struct cifs_writedata *wdata; struct page *page; - struct pagevec pvec; int rc = 0; - int scanned = 0; - int xid; - - cifs_sb = CIFS_SB(mapping->host->i_sb); /* - * If wsize is smaller that the page cache size, default to writing + * If wsize is smaller than the page cache size, default to writing * one page at a time via cifs_writepage */ if (cifs_sb->wsize < PAGE_CACHE_SIZE) return generic_writepages(mapping, wbc); - iov = kmalloc(32 * sizeof(struct kvec), GFP_KERNEL); - if (iov == NULL) - return generic_writepages(mapping, wbc); - - /* - * if there's no open file, then this is likely to fail too, - * but it'll at least handle the return. Maybe it should be - * a BUG() instead? - */ - open_file = find_writable_file(CIFS_I(mapping->host), false); - if (!open_file) { - kfree(iov); - return generic_writepages(mapping, wbc); - } - - tcon = tlink_tcon(open_file->tlink); - cifsFileInfo_put(open_file); - - xid = GetXid(); - - pagevec_init(&pvec, 0); if (wbc->range_cyclic) { index = mapping->writeback_index; /* Start from prev offset */ end = -1; @@ -1151,24 +1113,49 @@ static int cifs_writepages(struct address_space *mapping, index = wbc->range_start >> PAGE_CACHE_SHIFT; end = wbc->range_end >> PAGE_CACHE_SHIFT; if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) - range_whole = 1; - scanned = 1; + range_whole = true; + scanned = true; } retry: - while (!done && (index <= end) && - (nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, - PAGECACHE_TAG_DIRTY, - min(end - index, (pgoff_t)PAGEVEC_SIZE - 1) + 1))) { - int first; - unsigned int i; - - first = -1; - next = 0; - n_iov = 0; - bytes_to_write = 0; - - for (i = 0; i < nr_pages; i++) { - page = pvec.pages[i]; + while (!done && index <= end) { + unsigned int i, nr_pages, found_pages; + pgoff_t next = 0, tofind; + struct page **pages; + + tofind = min((cifs_sb->wsize / PAGE_CACHE_SIZE) - 1, + end - index) + 1; + + wdata = cifs_writedata_alloc((unsigned int)tofind); + if (!wdata) { + rc = -ENOMEM; + break; + } + + /* + * find_get_pages_tag seems to return a max of 256 on each + * iteration, so we must call it several times in order to + * fill the array or the wsize is effectively limited to + * 256 * PAGE_CACHE_SIZE. + */ + found_pages = 0; + pages = wdata->pages; + do { + nr_pages = find_get_pages_tag(mapping, &index, + PAGECACHE_TAG_DIRTY, + tofind, pages); + found_pages += nr_pages; + tofind -= nr_pages; + pages += nr_pages; + } while (nr_pages && tofind && index <= end); + + if (found_pages == 0) { + kref_put(&wdata->refcount, cifs_writedata_release); + break; + } + + nr_pages = 0; + for (i = 0; i < found_pages; i++) { + page = wdata->pages[i]; /* * At this point we hold neither mapping->tree_lock nor * lock on the page itself: the page may be truncated or @@ -1177,7 +1164,7 @@ retry: * mapping */ - if (first < 0) + if (nr_pages == 0) lock_page(page); else if (!trylock_page(page)) break; @@ -1188,7 +1175,7 @@ retry: } if (!wbc->range_cyclic && page->index > end) { - done = 1; + done = true; unlock_page(page); break; } @@ -1215,119 +1202,89 @@ retry: set_page_writeback(page); if (page_offset(page) >= mapping->host->i_size) { - done = 1; + done = true; unlock_page(page); end_page_writeback(page); break; } - /* - * BB can we get rid of this? pages are held by pvec - */ - page_cache_get(page); + wdata->pages[i] = page; + next = page->index + 1; + ++nr_pages; + } - len = min(mapping->host->i_size - page_offset(page), - (loff_t)PAGE_CACHE_SIZE); + /* reset index to refind any pages skipped */ + if (nr_pages == 0) + index = wdata->pages[0]->index + 1; - /* reserve iov[0] for the smb header */ - n_iov++; - iov[n_iov].iov_base = kmap(page); - iov[n_iov].iov_len = len; - bytes_to_write += len; + /* put any pages we aren't going to use */ + for (i = nr_pages; i < found_pages; i++) { + page_cache_release(wdata->pages[i]); + wdata->pages[i] = NULL; + } - if (first < 0) { - first = i; - offset = page_offset(page); - } - next = page->index + 1; - if (bytes_to_write + PAGE_CACHE_SIZE > cifs_sb->wsize) - break; + /* nothing to write? */ + if (nr_pages == 0) { + kref_put(&wdata->refcount, cifs_writedata_release); + continue; } - if (n_iov) { -retry_write: - open_file = find_writable_file(CIFS_I(mapping->host), - false); - if (!open_file) { - cERROR(1, "No writable handles for inode"); - rc = -EBADF; - } else { - rc = CIFSSMBWrite2(xid, tcon, open_file->netfid, - bytes_to_write, offset, - &bytes_written, iov, n_iov, - 0); - cifsFileInfo_put(open_file); - } - cFYI(1, "Write2 rc=%d, wrote=%u", rc, bytes_written); + wdata->sync_mode = wbc->sync_mode; + wdata->nr_pages = nr_pages; + wdata->offset = page_offset(wdata->pages[0]); - /* - * For now, treat a short write as if nothing got - * written. A zero length write however indicates - * ENOSPC or EFBIG. We have no way to know which - * though, so call it ENOSPC for now. EFBIG would - * get translated to AS_EIO anyway. - * - * FIXME: make it take into account the data that did - * get written - */ - if (rc == 0) { - if (bytes_written == 0) - rc = -ENOSPC; - else if (bytes_written < bytes_to_write) - rc = -EAGAIN; + do { + if (wdata->cfile != NULL) + cifsFileInfo_put(wdata->cfile); + wdata->cfile = find_writable_file(CIFS_I(mapping->host), + false); + if (!wdata->cfile) { + cERROR(1, "No writable handles for inode"); + rc = -EBADF; + break; } + rc = cifs_async_writev(wdata); + } while (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN); - /* retry on data-integrity flush */ - if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) - goto retry_write; + for (i = 0; i < nr_pages; ++i) + unlock_page(wdata->pages[i]); - /* fix the stats and EOF */ - if (bytes_written > 0) { - cifs_stats_bytes_written(tcon, bytes_written); - cifs_update_eof(cifsi, offset, bytes_written); - } - - for (i = 0; i < n_iov; i++) { - page = pvec.pages[first + i]; - /* on retryable write error, redirty page */ + /* send failure -- clean up the mess */ + if (rc != 0) { + for (i = 0; i < nr_pages; ++i) { if (rc == -EAGAIN) - redirty_page_for_writepage(wbc, page); - else if (rc != 0) - SetPageError(page); - kunmap(page); - unlock_page(page); - end_page_writeback(page); - page_cache_release(page); + redirty_page_for_writepage(wbc, + wdata->pages[i]); + else + SetPageError(wdata->pages[i]); + end_page_writeback(wdata->pages[i]); + page_cache_release(wdata->pages[i]); } - if (rc != -EAGAIN) mapping_set_error(mapping, rc); - else - rc = 0; + } + kref_put(&wdata->refcount, cifs_writedata_release); - if ((wbc->nr_to_write -= n_iov) <= 0) - done = 1; - index = next; - } else - /* Need to re-find the pages we skipped */ - index = pvec.pages[0]->index + 1; + wbc->nr_to_write -= nr_pages; + if (wbc->nr_to_write <= 0) + done = true; - pagevec_release(&pvec); + index = next; } + if (!scanned && !done) { /* * We hit the last page and there is more work to be done: wrap * back to the start of the file */ - scanned = 1; + scanned = true; index = 0; goto retry; } + if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) mapping->writeback_index = index; - FreeXid(xid); - kfree(iov); return rc; } |