1 files changed, 105 insertions, 336 deletions

diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index 9a10e68c5f30..862164181bac 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -12,389 +12,158 @@
 #include <linux/file.h>
 #include <linux/stat.h>
 #include <linux/string.h>
-#include <linux/inet.h>
 #include <linux/pagemap.h>
-#include <linux/idr.h>
 #include <linux/sched.h>
 #include <linux/swap.h>
 #include <linux/uio.h>
 #include <linux/netfs.h>
 #include <net/9p/9p.h>
 #include <net/9p/client.h>
+#include <trace/events/netfs.h>
 
 #include "v9fs.h"
 #include "v9fs_vfs.h"
 #include "cache.h"
 #include "fid.h"
 
-/**
- * v9fs_req_issue_op - Issue a read from 9P
- * @subreq: The read to make
+/*
+ * Writeback calls this when it finds a folio that needs uploading.  This isn't
+ * called if writeback only has copy-to-cache to deal with.
  */
-static void v9fs_req_issue_op(struct netfs_read_subrequest *subreq)
+static void v9fs_begin_writeback(struct netfs_io_request *wreq)
 {
-	struct netfs_read_request *rreq = subreq->rreq;
-	struct p9_fid *fid = rreq->netfs_priv;
-	struct iov_iter to;
-	loff_t pos = subreq->start + subreq->transferred;
-	size_t len = subreq->len   - subreq->transferred;
-	int total, err;
-
-	iov_iter_xarray(&to, READ, &rreq->mapping->i_pages, pos, len);
+	struct p9_fid *fid;
 
-	total = p9_client_read(fid, pos, &to, &err);
-
-	/* if we just extended the file size, any portion not in
-	 * cache won't be on server and is zeroes */
-	__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
+	fid = v9fs_fid_find_inode(wreq->inode, true, INVALID_UID, true);
+	if (!fid) {
+		WARN_ONCE(1, "folio expected an open fid inode->i_ino=%lx\n",
+			  wreq->inode->i_ino);
+		return;
+	}
 
-	netfs_subreq_terminated(subreq, err ?: total, false);
+	wreq->wsize = fid->clnt->msize - P9_IOHDRSZ;
+	if (fid->iounit)
+		wreq->wsize = min(wreq->wsize, fid->iounit);
+	wreq->netfs_priv = fid;
+	wreq->io_streams[0].avail = true;
 }
 
-/**
- * v9fs_init_rreq - Initialise a read request
- * @rreq: The read request
- * @file: The file being read from
+/*
+ * Issue a subrequest to write to the server.
  */
-static void v9fs_init_rreq(struct netfs_read_request *rreq, struct file *file)
+static void v9fs_issue_write(struct netfs_io_subrequest *subreq)
 {
-	struct p9_fid *fid = file->private_data;
+	struct p9_fid *fid = subreq->rreq->netfs_priv;
+	int err, len;
 
-	refcount_inc(&fid->count);
-	rreq->netfs_priv = fid;
+	len = p9_client_write(fid, subreq->start, &subreq->io_iter, &err);
+	if (len > 0)
+		__set_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags);
+	netfs_write_subrequest_terminated(subreq, len ?: err);
 }
 
 /**
- * v9fs_req_cleanup - Cleanup request initialized by v9fs_init_rreq
- * @mapping: unused mapping of request to cleanup
- * @priv: private data to cleanup, a fid, guaranted non-null.
+ * v9fs_issue_read - Issue a read from 9P
+ * @subreq: The read to make
  */
-static void v9fs_req_cleanup(struct address_space *mapping, void *priv)
+static void v9fs_issue_read(struct netfs_io_subrequest *subreq)
 {
-	struct p9_fid *fid = priv;
+	struct netfs_io_request *rreq = subreq->rreq;
+	struct p9_fid *fid = rreq->netfs_priv;
+	unsigned long long pos = subreq->start + subreq->transferred;
+	int total, err;
 
-	p9_client_clunk(fid);
-}
+	total = p9_client_read(fid, pos, &subreq->io_iter, &err);
 
-/**
- * v9fs_is_cache_enabled - Determine if caching is enabled for an inode
- * @inode: The inode to check
- */
-static bool v9fs_is_cache_enabled(struct inode *inode)
-{
-	struct fscache_cookie *cookie = v9fs_inode_cookie(V9FS_I(inode));
+	/* if we just extended the file size, any portion not in
+	 * cache won't be on server and is zeroes */
+	if (subreq->rreq->origin != NETFS_UNBUFFERED_READ &&
+	    subreq->rreq->origin != NETFS_DIO_READ)
+		__set_bit(NETFS_SREQ_CLEAR_TAIL, &subreq->flags);
+	if (pos + total >= i_size_read(rreq->inode))
+		__set_bit(NETFS_SREQ_HIT_EOF, &subreq->flags);
+	if (!err && total) {
+		subreq->transferred += total;
+		__set_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags);
+	}
 
-	return fscache_cookie_enabled(cookie) && cookie->cache_priv;
+	subreq->error = err;
+	netfs_read_subreq_terminated(subreq);
 }
 
 /**
- * v9fs_begin_cache_operation - Begin a cache operation for a read
+ * v9fs_init_request - Initialise a request
  * @rreq: The read request
+ * @file: The file being read from
  */
-static int v9fs_begin_cache_operation(struct netfs_read_request *rreq)
-{
-#ifdef CONFIG_9P_FSCACHE
-	struct fscache_cookie *cookie = v9fs_inode_cookie(V9FS_I(rreq->inode));
-
-	return fscache_begin_read_operation(&rreq->cache_resources, cookie);
-#else
-	return -ENOBUFS;
-#endif
-}
-
-static const struct netfs_read_request_ops v9fs_req_ops = {
-	.init_rreq		= v9fs_init_rreq,
-	.is_cache_enabled	= v9fs_is_cache_enabled,
-	.begin_cache_operation	= v9fs_begin_cache_operation,
-	.issue_op		= v9fs_req_issue_op,
-	.cleanup		= v9fs_req_cleanup,
-};
-
-/**
- * v9fs_vfs_readpage - read an entire page in from 9P
- * @file: file being read
- * @page: structure to page
- *
- */
-static int v9fs_vfs_readpage(struct file *file, struct page *page)
-{
-	struct folio *folio = page_folio(page);
-
-	return netfs_readpage(file, folio, &v9fs_req_ops, NULL);
-}
-
-/**
- * v9fs_vfs_readahead - read a set of pages from 9P
- * @ractl: The readahead parameters
- */
-static void v9fs_vfs_readahead(struct readahead_control *ractl)
-{
-	netfs_readahead(ractl, &v9fs_req_ops, NULL);
-}
-
-/**
- * v9fs_release_page - release the private state associated with a page
- * @page: The page to be released
- * @gfp: The caller's allocation restrictions
- *
- * Returns 1 if the page can be released, false otherwise.
- */
-
-static int v9fs_release_page(struct page *page, gfp_t gfp)
-{
-	struct folio *folio = page_folio(page);
-	struct inode *inode = folio_inode(folio);
-
-	if (folio_test_private(folio))
-		return 0;
-#ifdef CONFIG_9P_FSCACHE
-	if (folio_test_fscache(folio)) {
-		if (current_is_kswapd() || !(gfp & __GFP_FS))
-			return 0;
-		folio_wait_fscache(folio);
-	}
-#endif
-	fscache_note_page_release(v9fs_inode_cookie(V9FS_I(inode)));
-	return 1;
-}
-
-/**
- * v9fs_invalidate_page - Invalidate a page completely or partially
- * @page: The page to be invalidated
- * @offset: offset of the invalidated region
- * @length: length of the invalidated region
- */
-
-static void v9fs_invalidate_page(struct page *page, unsigned int offset,
-				 unsigned int length)
-{
-	struct folio *folio = page_folio(page);
-
-	folio_wait_fscache(folio);
-}
-
-static void v9fs_write_to_cache_done(void *priv, ssize_t transferred_or_error,
-				     bool was_async)
-{
-	struct v9fs_inode *v9inode = priv;
-	__le32 version;
-
-	if (IS_ERR_VALUE(transferred_or_error) &&
-	    transferred_or_error != -ENOBUFS) {
-		version = cpu_to_le32(v9inode->qid.version);
-		fscache_invalidate(v9fs_inode_cookie(v9inode), &version,
-				   i_size_read(&v9inode->vfs_inode), 0);
-	}
-}
-
-static int v9fs_vfs_write_folio_locked(struct folio *folio)
-{
-	struct inode *inode = folio_inode(folio);
-	struct v9fs_inode *v9inode = V9FS_I(inode);
-	struct fscache_cookie *cookie = v9fs_inode_cookie(v9inode);
-	loff_t start = folio_pos(folio);
-	loff_t i_size = i_size_read(inode);
-	struct iov_iter from;
-	size_t len = folio_size(folio);
-	int err;
-
-	if (start >= i_size)
-		return 0; /* Simultaneous truncation occurred */
-
-	len = min_t(loff_t, i_size - start, len);
-
-	iov_iter_xarray(&from, WRITE, &folio_mapping(folio)->i_pages, start, len);
-
-	/* We should have writeback_fid always set */
-	BUG_ON(!v9inode->writeback_fid);
-
-	folio_wait_fscache(folio);
-	folio_start_writeback(folio);
-
-	p9_client_write(v9inode->writeback_fid, start, &from, &err);
-
-	if (err == 0 &&
-	    fscache_cookie_enabled(cookie) &&
-	    test_bit(FSCACHE_COOKIE_IS_CACHING, &cookie->flags)) {
-		folio_start_fscache(folio);
-		fscache_write_to_cache(v9fs_inode_cookie(v9inode),
-				       folio_mapping(folio), start, len, i_size,
-				       v9fs_write_to_cache_done, v9inode,
-				       true);
+static int v9fs_init_request(struct netfs_io_request *rreq, struct file *file)
+{
+	struct p9_fid *fid;
+	bool writing = (rreq->origin == NETFS_READ_FOR_WRITE ||
+			rreq->origin == NETFS_WRITETHROUGH ||
+			rreq->origin == NETFS_UNBUFFERED_WRITE ||
+			rreq->origin == NETFS_DIO_WRITE);
+
+	if (rreq->origin == NETFS_WRITEBACK)
+		return 0; /* We don't get the write handle until we find we
+			   * have actually dirty data and not just
+			   * copy-to-cache data.
+			   */
+
+	if (file) {
+		fid = file->private_data;
+		if (!fid)
+			goto no_fid;
+		p9_fid_get(fid);
+	} else {
+		fid = v9fs_fid_find_inode(rreq->inode, writing, INVALID_UID, true);
+		if (!fid)
+			goto no_fid;
 	}
 
-	folio_end_writeback(folio);
-	return err;
-}
-
-static int v9fs_vfs_writepage(struct page *page, struct writeback_control *wbc)
-{
-	struct folio *folio = page_folio(page);
-	int retval;
-
-	p9_debug(P9_DEBUG_VFS, "folio %p\n", folio);
-
-	retval = v9fs_vfs_write_folio_locked(folio);
-	if (retval < 0) {
-		if (retval == -EAGAIN) {
-			folio_redirty_for_writepage(wbc, folio);
-			retval = 0;
-		} else {
-			mapping_set_error(folio_mapping(folio), retval);
-		}
-	} else
-		retval = 0;
-
-	folio_unlock(folio);
-	return retval;
-}
+	rreq->wsize = fid->clnt->msize - P9_IOHDRSZ;
+	if (fid->iounit)
+		rreq->wsize = min(rreq->wsize, fid->iounit);
 
-/**
- * v9fs_launder_page - Writeback a dirty page
- * @page: The page to be cleaned up
- *
- * Returns 0 on success.
- */
-
-static int v9fs_launder_page(struct page *page)
-{
-	struct folio *folio = page_folio(page);
-	int retval;
-
-	if (folio_clear_dirty_for_io(folio)) {
-		retval = v9fs_vfs_write_folio_locked(folio);
-		if (retval)
-			return retval;
-	}
-	folio_wait_fscache(folio);
+	/* we might need to read from a fid that was opened write-only
+	 * for read-modify-write of page cache, use the writeback fid
+	 * for that */
+	WARN_ON(rreq->origin == NETFS_READ_FOR_WRITE && !(fid->mode & P9_ORDWR));
+	rreq->netfs_priv = fid;
 	return 0;
+
+no_fid:
+	WARN_ONCE(1, "folio expected an open fid inode->i_ino=%lx\n",
+		  rreq->inode->i_ino);
+	return -EINVAL;
 }
 
 /**
- * v9fs_direct_IO - 9P address space operation for direct I/O
- * @iocb: target I/O control block
- * @iter: The data/buffer to use
- *
- * The presence of v9fs_direct_IO() in the address space ops vector
- * allowes open() O_DIRECT flags which would have failed otherwise.
- *
- * In the non-cached mode, we shunt off direct read and write requests before
- * the VFS gets them, so this method should never be called.
- *
- * Direct IO is not 'yet' supported in the cached mode. Hence when
- * this routine is called through generic_file_aio_read(), the read/write fails
- * with an error.
- *
+ * v9fs_free_request - Cleanup request initialized by v9fs_init_rreq
+ * @rreq: The I/O request to clean up
  */
-static ssize_t
-v9fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
-{
-	struct file *file = iocb->ki_filp;
-	loff_t pos = iocb->ki_pos;
-	ssize_t n;
-	int err = 0;
-
-	if (iov_iter_rw(iter) == WRITE) {
-		n = p9_client_write(file->private_data, pos, iter, &err);
-		if (n) {
-			struct inode *inode = file_inode(file);
-			loff_t i_size = i_size_read(inode);
-
-			if (pos + n > i_size)
-				inode_add_bytes(inode, pos + n - i_size);
-		}
-	} else {
-		n = p9_client_read(file->private_data, pos, iter, &err);
-	}
-	return n ? n : err;
-}
-
-static int v9fs_write_begin(struct file *filp, struct address_space *mapping,
-			    loff_t pos, unsigned int len, unsigned int flags,
-			    struct page **subpagep, void **fsdata)
-{
-	int retval;
-	struct folio *folio;
-	struct v9fs_inode *v9inode = V9FS_I(mapping->host);
-
-	p9_debug(P9_DEBUG_VFS, "filp %p, mapping %p\n", filp, mapping);
-
-	BUG_ON(!v9inode->writeback_fid);
-
-	/* Prefetch area to be written into the cache if we're caching this
-	 * file.  We need to do this before we get a lock on the page in case
-	 * there's more than one writer competing for the same cache block.
-	 */
-	retval = netfs_write_begin(filp, mapping, pos, len, flags, &folio, fsdata,
-				   &v9fs_req_ops, NULL);
-	if (retval < 0)
-		return retval;
-
-	*subpagep = &folio->page;
-	return retval;
-}
-
-static int v9fs_write_end(struct file *filp, struct address_space *mapping,
-			  loff_t pos, unsigned int len, unsigned int copied,
-			  struct page *subpage, void *fsdata)
+static void v9fs_free_request(struct netfs_io_request *rreq)
 {
-	loff_t last_pos = pos + copied;
-	struct folio *folio = page_folio(subpage);
-	struct inode *inode = mapping->host;
-	struct v9fs_inode *v9inode = V9FS_I(inode);
-
-	p9_debug(P9_DEBUG_VFS, "filp %p, mapping %p\n", filp, mapping);
-
-	if (!folio_test_uptodate(folio)) {
-		if (unlikely(copied < len)) {
-			copied = 0;
-			goto out;
-		}
-
-		folio_mark_uptodate(folio);
-	}
-
-	/*
-	 * No need to use i_size_read() here, the i_size
-	 * cannot change under us because we hold the i_mutex.
-	 */
-	if (last_pos > inode->i_size) {
-		inode_add_bytes(inode, last_pos - inode->i_size);
-		i_size_write(inode, last_pos);
-		fscache_update_cookie(v9fs_inode_cookie(v9inode), NULL, &last_pos);
-	}
-	folio_mark_dirty(folio);
-out:
-	folio_unlock(folio);
-	folio_put(folio);
+	struct p9_fid *fid = rreq->netfs_priv;
 
-	return copied;
+	p9_fid_put(fid);
 }
 
-#ifdef CONFIG_9P_FSCACHE
-/*
- * Mark a page as having been made dirty and thus needing writeback.  We also
- * need to pin the cache object to write back to.
- */
-static int v9fs_set_page_dirty(struct page *page)
-{
-	struct v9fs_inode *v9inode = V9FS_I(page->mapping->host);
-
-	return fscache_set_page_dirty(page, v9fs_inode_cookie(v9inode));
-}
-#else
-#define v9fs_set_page_dirty __set_page_dirty_nobuffers
-#endif
+const struct netfs_request_ops v9fs_req_ops = {
+	.init_request		= v9fs_init_request,
+	.free_request		= v9fs_free_request,
+	.issue_read		= v9fs_issue_read,
+	.begin_writeback	= v9fs_begin_writeback,
+	.issue_write		= v9fs_issue_write,
+};
 
 const struct address_space_operations v9fs_addr_operations = {
-	.readpage = v9fs_vfs_readpage,
-	.readahead = v9fs_vfs_readahead,
-	.set_page_dirty = v9fs_set_page_dirty,
-	.writepage = v9fs_vfs_writepage,
-	.write_begin = v9fs_write_begin,
-	.write_end = v9fs_write_end,
-	.releasepage = v9fs_release_page,
-	.invalidatepage = v9fs_invalidate_page,
-	.launder_page = v9fs_launder_page,
-	.direct_IO = v9fs_direct_IO,
+	.read_folio		= netfs_read_folio,
+	.readahead		= netfs_readahead,
+	.dirty_folio		= netfs_dirty_folio,
+	.release_folio		= netfs_release_folio,
+	.invalidate_folio	= netfs_invalidate_folio,
+	.direct_IO		= noop_direct_IO,
+	.writepages		= netfs_writepages,
+	.migrate_folio		= filemap_migrate_folio,
 };