cifs: Transition from ->readpages() to ->readahead()
Transition the cifs filesystem from using the old ->readpages() method to using the new ->readahead() method. For the moment, this removes any invocation of fscache to read data from the local cache, leaving that to another patch. Signed-off-by: David Howells <dhowells@redhat.com> cc: Steve French <smfrench@gmail.com> cc: Shyam Prasad N <nspmangalore@gmail.com> cc: Matthew Wilcox <willy@infradead.org> cc: Jeff Layton <jlayton@kernel.org> cc: linux-cifs@vger.kernel.org cc: linux-cachefs@redhat.com Reviewed-by: Rohith Surabattula <rohiths@microsoft.com> Acked-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
David Howells
Steve French
Родитель
489f710a73
Коммит
052e04a52d
174
fs/cifs/file.c
174
fs/cifs/file.c
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@ -4269,8 +4269,6 @@ cifs_readv_complete(struct work_struct *work)
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for (i = 0; i < rdata->nr_pages; i++) {
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struct page *page = rdata->pages[i];
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lru_cache_add(page);
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if (rdata->result == 0 ||
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(rdata->result == -EAGAIN && got_bytes)) {
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flush_dcache_page(page);
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@ -4340,7 +4338,6 @@ readpages_fill_pages(struct TCP_Server_Info *server,
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* fill them until the writes are flushed.
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*/
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zero_user(page, 0, PAGE_SIZE);
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lru_cache_add(page);
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flush_dcache_page(page);
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SetPageUptodate(page);
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unlock_page(page);
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@ -4350,7 +4347,6 @@ readpages_fill_pages(struct TCP_Server_Info *server,
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continue;
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} else {
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/* no need to hold page hostage */
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lru_cache_add(page);
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unlock_page(page);
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put_page(page);
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rdata->pages[i] = NULL;
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@ -4393,92 +4389,16 @@ cifs_readpages_copy_into_pages(struct TCP_Server_Info *server,
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return readpages_fill_pages(server, rdata, iter, iter->count);
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}
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static int
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readpages_get_pages(struct address_space *mapping, struct list_head *page_list,
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unsigned int rsize, struct list_head *tmplist,
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unsigned int *nr_pages, loff_t *offset, unsigned int *bytes)
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{
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struct page *page, *tpage;
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unsigned int expected_index;
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int rc;
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gfp_t gfp = readahead_gfp_mask(mapping);
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INIT_LIST_HEAD(tmplist);
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page = lru_to_page(page_list);
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/*
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* Lock the page and put it in the cache. Since no one else
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* should have access to this page, we're safe to simply set
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* PG_locked without checking it first.
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*/
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__SetPageLocked(page);
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rc = add_to_page_cache_locked(page, mapping,
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page->index, gfp);
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/* give up if we can't stick it in the cache */
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if (rc) {
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__ClearPageLocked(page);
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return rc;
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}
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/* move first page to the tmplist */
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*offset = (loff_t)page->index << PAGE_SHIFT;
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*bytes = PAGE_SIZE;
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*nr_pages = 1;
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list_move_tail(&page->lru, tmplist);
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/* now try and add more pages onto the request */
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expected_index = page->index + 1;
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list_for_each_entry_safe_reverse(page, tpage, page_list, lru) {
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/* discontinuity ? */
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if (page->index != expected_index)
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break;
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/* would this page push the read over the rsize? */
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if (*bytes + PAGE_SIZE > rsize)
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break;
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__SetPageLocked(page);
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rc = add_to_page_cache_locked(page, mapping, page->index, gfp);
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if (rc) {
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__ClearPageLocked(page);
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break;
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}
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list_move_tail(&page->lru, tmplist);
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(*bytes) += PAGE_SIZE;
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expected_index++;
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(*nr_pages)++;
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}
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return rc;
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}
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static int cifs_readpages(struct file *file, struct address_space *mapping,
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struct list_head *page_list, unsigned num_pages)
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static void cifs_readahead(struct readahead_control *ractl)
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{
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int rc;
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int err = 0;
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struct list_head tmplist;
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struct cifsFileInfo *open_file = file->private_data;
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struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
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struct cifsFileInfo *open_file = ractl->file->private_data;
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struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(ractl->file);
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struct TCP_Server_Info *server;
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pid_t pid;
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unsigned int xid;
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unsigned int xid, last_batch_size = 0;
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xid = get_xid();
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/*
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* Reads as many pages as possible from fscache. Returns -ENOBUFS
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* immediately if the cookie is negative
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*
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* After this point, every page in the list might have PG_fscache set,
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* so we will need to clean that up off of every page we don't use.
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*/
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rc = cifs_readpages_from_fscache(mapping->host, mapping, page_list,
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&num_pages);
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if (rc == 0) {
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free_xid(xid);
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return rc;
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}
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if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
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pid = open_file->pid;
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@ -4489,39 +4409,32 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
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server = cifs_pick_channel(tlink_tcon(open_file->tlink)->ses);
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cifs_dbg(FYI, "%s: file=%p mapping=%p num_pages=%u\n",
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__func__, file, mapping, num_pages);
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__func__, ractl->file, ractl->mapping, readahead_count(ractl));
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/*
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* Start with the page at end of list and move it to private
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* list. Do the same with any following pages until we hit
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* the rsize limit, hit an index discontinuity, or run out of
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* pages. Issue the async read and then start the loop again
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* until the list is empty.
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*
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* Note that list order is important. The page_list is in
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* the order of declining indexes. When we put the pages in
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* the rdata->pages, then we want them in increasing order.
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* Chop the readahead request up into rsize-sized read requests.
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*/
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while (!list_empty(page_list) && !err) {
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unsigned int i, nr_pages, bytes, rsize;
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loff_t offset;
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struct page *page, *tpage;
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while (readahead_count(ractl) - last_batch_size) {
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unsigned int i, nr_pages, got, rsize;
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struct page *page;
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struct cifs_readdata *rdata;
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struct cifs_credits credits_on_stack;
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struct cifs_credits *credits = &credits_on_stack;
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if (open_file->invalidHandle) {
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rc = cifs_reopen_file(open_file, true);
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if (rc == -EAGAIN)
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continue;
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else if (rc)
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if (rc) {
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if (rc == -EAGAIN)
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continue;
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break;
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}
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}
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rc = server->ops->wait_mtu_credits(server, cifs_sb->ctx->rsize,
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&rsize, credits);
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if (rc)
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break;
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nr_pages = min_t(size_t, rsize / PAGE_SIZE, readahead_count(ractl));
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/*
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* Give up immediately if rsize is too small to read an entire
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@ -4529,16 +4442,7 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
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* reach this point however since we set ra_pages to 0 when the
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* rsize is smaller than a cache page.
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*/
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if (unlikely(rsize < PAGE_SIZE)) {
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add_credits_and_wake_if(server, credits, 0);
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free_xid(xid);
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return 0;
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}
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nr_pages = 0;
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err = readpages_get_pages(mapping, page_list, rsize, &tmplist,
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&nr_pages, &offset, &bytes);
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if (!nr_pages) {
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if (unlikely(!nr_pages)) {
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add_credits_and_wake_if(server, credits, 0);
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break;
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}
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@ -4546,36 +4450,31 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
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rdata = cifs_readdata_alloc(nr_pages, cifs_readv_complete);
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if (!rdata) {
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/* best to give up if we're out of mem */
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list_for_each_entry_safe(page, tpage, &tmplist, lru) {
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list_del(&page->lru);
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lru_cache_add(page);
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unlock_page(page);
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put_page(page);
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}
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rc = -ENOMEM;
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add_credits_and_wake_if(server, credits, 0);
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break;
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}
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rdata->cfile = cifsFileInfo_get(open_file);
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rdata->server = server;
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rdata->mapping = mapping;
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rdata->offset = offset;
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rdata->bytes = bytes;
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rdata->pid = pid;
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rdata->pagesz = PAGE_SIZE;
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rdata->tailsz = PAGE_SIZE;
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rdata->read_into_pages = cifs_readpages_read_into_pages;
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rdata->copy_into_pages = cifs_readpages_copy_into_pages;
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rdata->credits = credits_on_stack;
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list_for_each_entry_safe(page, tpage, &tmplist, lru) {
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list_del(&page->lru);
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rdata->pages[rdata->nr_pages++] = page;
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got = __readahead_batch(ractl, rdata->pages, nr_pages);
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if (got != nr_pages) {
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pr_warn("__readahead_batch() returned %u/%u\n",
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got, nr_pages);
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nr_pages = got;
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}
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rc = adjust_credits(server, &rdata->credits, rdata->bytes);
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rdata->nr_pages = nr_pages;
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rdata->bytes = readahead_batch_length(ractl);
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rdata->cfile = cifsFileInfo_get(open_file);
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rdata->server = server;
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rdata->mapping = ractl->mapping;
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rdata->offset = readahead_pos(ractl);
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rdata->pid = pid;
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rdata->pagesz = PAGE_SIZE;
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rdata->tailsz = PAGE_SIZE;
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rdata->read_into_pages = cifs_readpages_read_into_pages;
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rdata->copy_into_pages = cifs_readpages_copy_into_pages;
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rdata->credits = credits_on_stack;
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rc = adjust_credits(server, &rdata->credits, rdata->bytes);
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if (!rc) {
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if (rdata->cfile->invalidHandle)
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rc = -EAGAIN;
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@ -4587,7 +4486,6 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
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add_credits_and_wake_if(server, &rdata->credits, 0);
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for (i = 0; i < rdata->nr_pages; i++) {
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page = rdata->pages[i];
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lru_cache_add(page);
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unlock_page(page);
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put_page(page);
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}
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@ -4597,10 +4495,10 @@ static int cifs_readpages(struct file *file, struct address_space *mapping,
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}
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kref_put(&rdata->refcount, cifs_readdata_release);
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last_batch_size = nr_pages;
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}
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free_xid(xid);
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return rc;
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}
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/*
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@ -4924,7 +4822,7 @@ oplock_break_done:
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* In the non-cached mode (mount with cache=none), we shunt off direct read and write requests
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* so this method should never be called.
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*
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* Direct IO is not yet supported in the cached mode.
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* Direct IO is not yet supported in the cached mode.
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*/
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static ssize_t
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cifs_direct_io(struct kiocb *iocb, struct iov_iter *iter)
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@ -5006,7 +4904,7 @@ static int cifs_set_page_dirty(struct page *page)
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const struct address_space_operations cifs_addr_ops = {
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.readpage = cifs_readpage,
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.readpages = cifs_readpages,
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.readahead = cifs_readahead,
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.writepage = cifs_writepage,
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.writepages = cifs_writepages,
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.write_begin = cifs_write_begin,
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