[RFC 11/13] cifs: Remove unused code

David Howells
2023-01-25T21:49:42Z

Remove a bunch of functions that are no longer used and are commented out
after the conversion to use iterators throughout the I/O path.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <sfrench@samba.org>
cc: Shyam Prasad N <nspmangalore@gmail.com>
cc: Rohith Surabattula <rohiths.msft@gmail.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cifs@vger.kernel.org

Link: https://lore.kernel.org/r/164928621823.457102.8777804402615654773.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165211421039.3154751.15199634443157779005.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165348881165.2106726.2993852968344861224.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165364827876.3334034.9331465096417303889.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/166126396915.708021.2010212654244139442.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/166697261080.61150.17513116912567922274.stgit@warthog.procyon.org.uk/ # rfc
Link: https://lore.kernel.org/r/166732033255.3186319.5527423437137895940.stgit@warthog.procyon.org.uk/ # rfc
---
fs/cifs/file.c | 606 -------------------------------------------------
1 file changed, 606 deletions(-)

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 8cf8ff2fc97b..89d59723bda8 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2603,314 +2603,6 @@ static int cifs_partialpagewrite(struct page *page, unsigned from, unsigned to)
return rc;
}

-#if 0 // TODO: Remove for iov_iter support
-static struct cifs_writedata *
-wdata_alloc_and_fillpages(pgoff_t tofind, struct address_space *mapping,
- pgoff_t end, pgoff_t *index,
- unsigned int *found_pages)
-{
- struct cifs_writedata *wdata;
-
- wdata = cifs_writedata_alloc((unsigned int)tofind,
- cifs_writev_complete);
- if (!wdata)
- return NULL;
-
- *found_pages = find_get_pages_range_tag(mapping, index, end,
- PAGECACHE_TAG_DIRTY, tofind, wdata->pages);
- return wdata;
-}
-
-static unsigned int
-wdata_prepare_pages(struct cifs_writedata *wdata, unsigned int found_pages,
- struct address_space *mapping,
- struct writeback_control *wbc,
- pgoff_t end, pgoff_t *index, pgoff_t *next, bool *done)
-{
- unsigned int nr_pages = 0, i;
- struct page *page;
-
- for (i = 0; i < found_pages; i++) {
- page = wdata->pages[i];
- /*
- * At this point we hold neither the i_pages lock nor the
- * page lock: the page may be truncated or invalidated
- * (changing page->mapping to NULL), or even swizzled
- * back from swapper_space to tmpfs file mapping
- */
-
- if (nr_pages == 0)
- lock_page(page);
- else if (!trylock_page(page))
- break;
-
- if (unlikely(page->mapping != mapping)) {
- unlock_page(page);
- break;
- }
-
- if (!wbc->range_cyclic && page->index > end) {
- *done = true;
- unlock_page(page);
- break;
- }
-
- if (*next && (page->index != *next)) {
- /* Not next consecutive page */
- unlock_page(page);
- break;
- }
-
- if (wbc->sync_mode != WB_SYNC_NONE)
- wait_on_page_writeback(page);
-
- if (PageWriteback(page) ||
- !clear_page_dirty_for_io(page)) {
- unlock_page(page);
- break;
- }
-
- /*
- * This actually clears the dirty bit in the radix tree.
- * See cifs_writepage() for more commentary.
- */
- set_page_writeback(page);
- if (page_offset(page) >= i_size_read(mapping->host)) {
- *done = true;
- unlock_page(page);
- end_page_writeback(page);
- break;
- }
-
- wdata->pages[i] = page;
- *next = page->index + 1;
- ++nr_pages;
- }
-
- /* reset index to refind any pages skipped */
- if (nr_pages == 0)
- *index = wdata->pages[0]->index + 1;
-
- /* put any pages we aren't going to use */
- for (i = nr_pages; i < found_pages; i++) {
- put_page(wdata->pages[i]);
- wdata->pages[i] = NULL;
- }
-
- return nr_pages;
-}
-
-static int
-wdata_send_pages(struct cifs_writedata *wdata, unsigned int nr_pages,
- struct address_space *mapping, struct writeback_control *wbc)
-{
- int rc;
-
- wdata->sync_mode = wbc->sync_mode;
- wdata->nr_pages = nr_pages;
- wdata->offset = page_offset(wdata->pages[0]);
- wdata->pagesz = PAGE_SIZE;
- wdata->tailsz = min(i_size_read(mapping->host) -
- page_offset(wdata->pages[nr_pages - 1]),
- (loff_t)PAGE_SIZE);
- wdata->bytes = ((nr_pages - 1) * PAGE_SIZE) + wdata->tailsz;
- wdata->pid = wdata->cfile->pid;
-
- rc = adjust_credits(wdata->server, &wdata->credits, wdata->bytes);
- if (rc)
- return rc;
-
- if (wdata->cfile->invalidHandle)
- rc = -EAGAIN;
- else
- rc = wdata->server->ops->async_writev(wdata,
- cifs_writedata_release);
-
- return rc;
-}
-
-static int
-cifs_writepage_locked(struct page *page, struct writeback_control *wbc);
-
-static int cifs_write_one_page(struct page *page, struct writeback_control *wbc,
- void *data)
-{
- struct address_space *mapping = data;
- int ret;
-
- ret = cifs_writepage_locked(page, wbc);
- unlock_page(page);
- mapping_set_error(mapping, ret);
- return ret;
-}
-
-static int cifs_writepages(struct address_space *mapping,
- struct writeback_control *wbc)
-{
- struct inode *inode = mapping->host;
- struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
- struct TCP_Server_Info *server;
- bool done = false, scanned = false, range_whole = false;
- pgoff_t end, index;
- struct cifs_writedata *wdata;
- struct cifsFileInfo *cfile = NULL;
- int rc = 0;
- int saved_rc = 0;
- unsigned int xid;
-
- /*
- * If wsize is smaller than the page cache size, default to writing
- * one page at a time.
- */
- if (cifs_sb->ctx->wsize < PAGE_SIZE)
- return write_cache_pages(mapping, wbc, cifs_write_one_page,
- mapping);
-
- xid = get_xid();
- if (wbc->range_cyclic) {
- index = mapping->writeback_index; /* Start from prev offset */
- end = -1;
- } else {
- index = wbc->range_start >> PAGE_SHIFT;
- end = wbc->range_end >> PAGE_SHIFT;
- if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
- range_whole = true;
- scanned = true;
- }
- server = cifs_pick_channel(cifs_sb_master_tcon(cifs_sb)->ses);
-
-retry:
- while (!done && index <= end) {
- unsigned int i, nr_pages, found_pages, wsize;
- pgoff_t next = 0, tofind, saved_index = index;
- struct cifs_credits credits_on_stack;
- struct cifs_credits *credits = &credits_on_stack;
- int get_file_rc = 0;
-
- if (cfile)
- cifsFileInfo_put(cfile);
-
- rc = cifs_get_writable_file(CIFS_I(inode), FIND_WR_ANY, &cfile);
-
- /* in case of an error store it to return later */
- if (rc)
- get_file_rc = rc;
-
- rc = server->ops->wait_mtu_credits(server, cifs_sb->ctx->wsize,
- &wsize, credits);
- if (rc != 0) {
- done = true;
- break;
- }
-
- tofind = min((wsize / PAGE_SIZE) - 1, end - index) + 1;
-
- wdata = wdata_alloc_and_fillpages(tofind, mapping, end, &index,
- &found_pages);
- if (!wdata) {
- rc = -ENOMEM;
- done = true;
- add_credits_and_wake_if(server, credits, 0);
- break;
- }
-
- if (found_pages == 0) {
- kref_put(&wdata->refcount, cifs_writedata_release);
- add_credits_and_wake_if(server, credits, 0);
- break;
- }
-
- nr_pages = wdata_prepare_pages(wdata, found_pages, mapping, wbc,
- end, &index, &next, &done);
-
- /* nothing to write? */
- if (nr_pages == 0) {
- kref_put(&wdata->refcount, cifs_writedata_release);
- add_credits_and_wake_if(server, credits, 0);
- continue;
- }
-
- wdata->credits = credits_on_stack;
- wdata->cfile = cfile;
- wdata->server = server;
- cfile = NULL;
-
- if (!wdata->cfile) {
- cifs_dbg(VFS, "No writable handle in writepages rc=%d\n",
- get_file_rc);
- if (is_retryable_error(get_file_rc))
- rc = get_file_rc;
- else
- rc = -EBADF;
- } else
- rc = wdata_send_pages(wdata, nr_pages, mapping, wbc);
-
- for (i = 0; i < nr_pages; ++i)
- unlock_page(wdata->pages[i]);
-
- /* send failure -- clean up the mess */
- if (rc != 0) {
- add_credits_and_wake_if(server, &wdata->credits, 0);
- for (i = 0; i < nr_pages; ++i) {
- if (is_retryable_error(rc))
- redirty_page_for_writepage(wbc,
- wdata->pages[i]);
- else
- SetPageError(wdata->pages[i]);
- end_page_writeback(wdata->pages[i]);
- put_page(wdata->pages[i]);
- }
- if (!is_retryable_error(rc))
- mapping_set_error(mapping, rc);
- }
- kref_put(&wdata->refcount, cifs_writedata_release);
-
- if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN) {
- index = saved_index;
- continue;
- }
-
- /* Return immediately if we received a signal during writing */
- if (is_interrupt_error(rc)) {
- done = true;
- break;
- }
-
- if (rc != 0 && saved_rc == 0)
- saved_rc = rc;
-
- wbc->nr_to_write -= nr_pages;
- if (wbc->nr_to_write <= 0)
- done = true;
-
- 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 = true;
- index = 0;
- goto retry;
- }
-
- if (saved_rc != 0)
- rc = saved_rc;
-
- if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
- mapping->writeback_index = index;
-
- if (cfile)
- cifsFileInfo_put(cfile);
- free_xid(xid);
- /* Indication to update ctime and mtime as close is deferred */
- set_bit(CIFS_INO_MODIFIED_ATTR, &CIFS_I(inode)->flags);
- return rc;
-}
-#endif
-
/*
* Extend the region to be written back to include subsequent contiguously
* dirty pages if possible, but don't sleep while doing so.
@@ -3505,49 +3197,6 @@ int cifs_flush(struct file *file, fl_owner_t id)
return rc;
}

-#if 0 // TODO: Remove for iov_iter support
-static int
-cifs_write_allocate_pages(struct page **pages, unsigned long num_pages)
-{
- int rc = 0;
- unsigned long i;
-
- for (i = 0; i < num_pages; i++) {
- pages[i] = alloc_page(GFP_KERNEL|__GFP_HIGHMEM);
- if (!pages[i]) {
- /*
- * save number of pages we have already allocated and
- * return with ENOMEM error
- */
- num_pages = i;
- rc = -ENOMEM;
- break;
- }
- }
-
- if (rc) {
- for (i = 0; i < num_pages; i++)
- put_page(pages[i]);
- }
- return rc;
-}
-
-static inline
-size_t get_numpages(const size_t wsize, const size_t len, size_t *cur_len)
-{
- size_t num_pages;
- size_t clen;
-
- clen = min_t(const size_t, len, wsize);
- num_pages = DIV_ROUND_UP(clen, PAGE_SIZE);
-
- if (cur_len)
- *cur_len = clen;
-
- return num_pages;
-}
-#endif
-
static void
cifs_uncached_writedata_release(struct kref *refcount)
{
@@ -3580,50 +3229,6 @@ cifs_uncached_writev_complete(struct work_struct *work)
kref_put(&wdata->refcount, cifs_uncached_writedata_release);
}

-#if 0 // TODO: Remove for iov_iter support
-static int
-wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from,
- size_t *len, unsigned long *num_pages)
-{
- size_t save_len, copied, bytes, cur_len = *len;
- unsigned long i, nr_pages = *num_pages;
-
- save_len = cur_len;
- for (i = 0; i < nr_pages; i++) {
- bytes = min_t(const size_t, cur_len, PAGE_SIZE);
- copied = copy_page_from_iter(wdata->pages[i], 0, bytes, from);
- cur_len -= copied;
- /*
- * If we didn't copy as much as we expected, then that
- * may mean we trod into an unmapped area. Stop copying
- * at that point. On the next pass through the big
- * loop, we'll likely end up getting a zero-length
- * write and bailing out of it.
- */
- if (copied < bytes)
- break;
- }
- cur_len = save_len - cur_len;
- *len = cur_len;
-
- /*
- * If we have no data to send, then that probably means that
- * the copy above failed altogether. That's most likely because
- * the address in the iovec was bogus. Return -EFAULT and let
- * the caller free anything we allocated and bail out.
- */
- if (!cur_len)
- return -EFAULT;
-
- /*
- * i + 1 now represents the number of pages we actually used in
- * the copy phase above.
- */
- *num_pages = i + 1;
- return 0;
-}
-#endif
-
static int
cifs_resend_wdata(struct cifs_writedata *wdata, struct list_head *wdata_list,
struct cifs_aio_ctx *ctx)
@@ -4210,83 +3815,6 @@ cifs_uncached_readv_complete(struct work_struct *work)
kref_put(&rdata->refcount, cifs_readdata_release);
}

-#if 0 // TODO: Remove for iov_iter support
-
-static int
-uncached_fill_pages(struct TCP_Server_Info *server,
- struct cifs_readdata *rdata, struct iov_iter *iter,
- unsigned int len)
-{
- int result = 0;
- unsigned int i;
- unsigned int nr_pages = rdata->nr_pages;
- unsigned int page_offset = rdata->page_offset;
-
- rdata->got_bytes = 0;
- rdata->tailsz = PAGE_SIZE;
- for (i = 0; i < nr_pages; i++) {
- struct page *page = rdata->pages[i];
- size_t n;
- unsigned int segment_size = rdata->pagesz;
-
- if (i == 0)
- segment_size -= page_offset;
- else
- page_offset = 0;
-
-
- if (len <= 0) {
- /* no need to hold page hostage */
- rdata->pages[i] = NULL;
- rdata->nr_pages--;
- put_page(page);
- continue;
- }
-
- n = len;
- if (len >= segment_size)
- /* enough data to fill the page */
- n = segment_size;
- else
- rdata->tailsz = len;
- len -= n;
-
- if (iter)
- result = copy_page_from_iter(
- page, page_offset, n, iter);
-#ifdef CONFIG_CIFS_SMB_DIRECT
- else if (rdata->mr)
- result = n;
-#endif
- else
- result = cifs_read_page_from_socket(
- server, page, page_offset, n);
- if (result < 0)
- break;
-
- rdata->got_bytes += result;
- }
-
- return rdata->got_bytes > 0 && result != -ECONNABORTED ?
- rdata->got_bytes : result;
-}
-
-static int
-cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
- struct cifs_readdata *rdata, unsigned int len)
-{
- return uncached_fill_pages(server, rdata, NULL, len);
-}
-
-static int
-cifs_uncached_copy_into_pages(struct TCP_Server_Info *server,
- struct cifs_readdata *rdata,
- struct iov_iter *iter)
-{
- return uncached_fill_pages(server, rdata, iter, iter->count);
-}
-#endif
-
static int cifs_resend_rdata(struct cifs_readdata *rdata,
struct list_head *rdata_list,
struct cifs_aio_ctx *ctx)
@@ -4897,140 +4425,6 @@ int cifs_file_mmap(struct file *file, struct vm_area_struct *vma)
return rc;
}

-#if 0 // TODO: Remove for iov_iter support
-
-static void
-cifs_readv_complete(struct work_struct *work)
-{
- unsigned int i, got_bytes;
- struct cifs_readdata *rdata = container_of(work,
- struct cifs_readdata, work);
-
- got_bytes = rdata->got_bytes;
- for (i = 0; i < rdata->nr_pages; i++) {
- struct page *page = rdata->pages[i];
-
- if (rdata->result == 0 ||
- (rdata->result == -EAGAIN && got_bytes)) {
- flush_dcache_page(page);
- SetPageUptodate(page);
- } else
- SetPageError(page);
-
- if (rdata->result == 0 ||
- (rdata->result == -EAGAIN && got_bytes))
- cifs_readpage_to_fscache(rdata->mapping->host, page);
-
- unlock_page(page);
-
- got_bytes -= min_t(unsigned int, PAGE_SIZE, got_bytes);
-
- put_page(page);
- rdata->pages[i] = NULL;
- }
- kref_put(&rdata->refcount, cifs_readdata_release);
-}
-
-static int
-readpages_fill_pages(struct TCP_Server_Info *server,
- struct cifs_readdata *rdata, struct iov_iter *iter,
- unsigned int len)
-{
- int result = 0;
- unsigned int i;
- u64 eof;
- pgoff_t eof_index;
- unsigned int nr_pages = rdata->nr_pages;
- unsigned int page_offset = rdata->page_offset;
-
- /* determine the eof that the server (probably) has */
- eof = CIFS_I(rdata->mapping->host)->server_eof;
- eof_index = eof ? (eof - 1) >> PAGE_SHIFT : 0;
- cifs_dbg(FYI, "eof=%llu eof_index=%lu\n", eof, eof_index);
-
- rdata->got_bytes = 0;
- rdata->tailsz = PAGE_SIZE;
- for (i = 0; i < nr_pages; i++) {
- struct page *page = rdata->pages[i];
- unsigned int to_read = rdata->pagesz;
- size_t n;
-
- if (i == 0)
- to_read -= page_offset;
- else
- page_offset = 0;
-
- n = to_read;
-
- if (len >= to_read) {
- len -= to_read;
- } else if (len > 0) {
- /* enough for partial page, fill and zero the rest */
- zero_user(page, len + page_offset, to_read - len);
- n = rdata->tailsz = len;
- len = 0;
- } else if (page->index > eof_index) {
- /*
- * The VFS will not try to do readahead past the
- * i_size, but it's possible that we have outstanding
- * writes with gaps in the middle and the i_size hasn't
- * caught up yet. Populate those with zeroed out pages
- * to prevent the VFS from repeatedly attempting to
- * fill them until the writes are flushed.
- */
- zero_user(page, 0, PAGE_SIZE);
- flush_dcache_page(page);
- SetPageUptodate(page);
- unlock_page(page);
- put_page(page);
- rdata->pages[i] = NULL;
- rdata->nr_pages--;
- continue;
- } else {
- /* no need to hold page hostage */
- unlock_page(page);
- put_page(page);
- rdata->pages[i] = NULL;
- rdata->nr_pages--;
- continue;
- }
-
- if (iter)
- result = copy_page_from_iter(
- page, page_offset, n, iter);
-#ifdef CONFIG_CIFS_SMB_DIRECT
- else if (rdata->mr)
- result = n;
-#endif
- else
- result = cifs_read_page_from_socket(
- server, page, page_offset, n);
- if (result < 0)
- break;
-
- rdata->got_bytes += result;
- }
-
- return rdata->got_bytes > 0 && result != -ECONNABORTED ?
- rdata->got_bytes : result;
-}
-
-static int
-cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
- struct cifs_readdata *rdata, unsigned int len)
-{
- return readpages_fill_pages(server, rdata, NULL, len);
-}
-
-static int
-cifs_readpages_copy_into_pages(struct TCP_Server_Info *server,
- struct cifs_readdata *rdata,
- struct iov_iter *iter)
-{
- return readpages_fill_pages(server, rdata, iter, iter->count);
-}
-#endif
-
/*
* Unlock a bunch of folios in the pagecache.
*/