Merge tag '5.7-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "Ten cifs/smb fixes:

   - five RDMA (smbdirect) related fixes

   - add experimental support for swap over SMB3 mounts

   - also a fix which improves performance of signed connections"

* tag '5.7-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: enable swap on SMB3 mounts
  smb3: change noisy error message to FYI
  smb3: smbdirect support can be configured by default
  cifs: smbd: Do not schedule work to send immediate packet on every receive
  cifs: smbd: Properly process errors on ib_post_send
  cifs: Allocate crypto structures on the fly for calculating signatures of incoming packets
  cifs: smbd: Update receive credits before sending and deal with credits roll back on failure before sending
  cifs: smbd: Check send queue size before posting a send
  cifs: smbd: Merge code to track pending packets
  cifs: ignore cached share root handle closing errors

1 files changed, 61 insertions, 0 deletions

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 5920820bfbd0..0b1528edebcf 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -4808,6 +4808,60 @@ cifs_direct_io(struct kiocb *iocb, struct iov_iter *iter)
         return -EINVAL;
 }
 
+static int cifs_swap_activate(struct swap_info_struct *sis,
+			      struct file *swap_file, sector_t *span)
+{
+	struct cifsFileInfo *cfile = swap_file->private_data;
+	struct inode *inode = swap_file->f_mapping->host;
+	unsigned long blocks;
+	long long isize;
+
+	cifs_dbg(FYI, "swap activate\n");
+
+	spin_lock(&inode->i_lock);
+	blocks = inode->i_blocks;
+	isize = inode->i_size;
+	spin_unlock(&inode->i_lock);
+	if (blocks*512 < isize) {
+		pr_warn("swap activate: swapfile has holes\n");
+		return -EINVAL;
+	}
+	*span = sis->pages;
+
+	printk_once(KERN_WARNING "Swap support over SMB3 is experimental\n");
+
+	/*
+	 * TODO: consider adding ACL (or documenting how) to prevent other
+	 * users (on this or other systems) from reading it
+	 */
+
+
+	/* TODO: add sk_set_memalloc(inet) or similar */
+
+	if (cfile)
+		cfile->swapfile = true;
+	/*
+	 * TODO: Since file already open, we can't open with DENY_ALL here
+	 * but we could add call to grab a byte range lock to prevent others
+	 * from reading or writing the file
+	 */
+
+	return 0;
+}
+
+static void cifs_swap_deactivate(struct file *file)
+{
+	struct cifsFileInfo *cfile = file->private_data;
+
+	cifs_dbg(FYI, "swap deactivate\n");
+
+	/* TODO: undo sk_set_memalloc(inet) will eventually be needed */
+
+	if (cfile)
+		cfile->swapfile = false;
+
+	/* do we need to unpin (or unlock) the file */
+}
 
 const struct address_space_operations cifs_addr_ops = {
 	.readpage = cifs_readpage,
@@ -4821,6 +4875,13 @@ const struct address_space_operations cifs_addr_ops = {
 	.direct_IO = cifs_direct_io,
 	.invalidatepage = cifs_invalidate_page,
 	.launder_page = cifs_launder_page,
+	/*
+	 * TODO: investigate and if useful we could add an cifs_migratePage
+	 * helper (under an CONFIG_MIGRATION) in the future, and also
+	 * investigate and add an is_dirty_writeback helper if needed
+	 */
+	.swap_activate = cifs_swap_activate,
+	.swap_deactivate = cifs_swap_deactivate,
 };
 
 /*