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-rw-r--r--fs/cifs/cifsfs.c4
-rw-r--r--fs/cifs/cifsglob.h1
-rw-r--r--fs/cifs/file.c61
-rw-r--r--fs/cifs/inode.c4
4 files changed, 70 insertions, 0 deletions
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 94e3ed4850b5..c31f362fa098 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -1208,6 +1208,10 @@ static ssize_t cifs_copy_file_range(struct file *src_file, loff_t off,
{
unsigned int xid = get_xid();
ssize_t rc;
+ struct cifsFileInfo *cfile = dst_file->private_data;
+
+ if (cfile->swapfile)
+ return -EOPNOTSUPP;
rc = cifs_file_copychunk_range(xid, src_file, off, dst_file, destoff,
len, flags);
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 7448e7202e7a..05dd3dea684b 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1313,6 +1313,7 @@ struct cifsFileInfo {
struct tcon_link *tlink;
unsigned int f_flags;
bool invalidHandle:1; /* file closed via session abend */
+ bool swapfile:1;
bool oplock_break_cancelled:1;
unsigned int oplock_epoch; /* epoch from the lease break */
__u32 oplock_level; /* oplock/lease level from the lease break */
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,
};
/*
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 8d01ec2dca66..8fbbdcdad8ff 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -2026,6 +2026,10 @@ cifs_revalidate_mapping(struct inode *inode)
int rc;
unsigned long *flags = &CIFS_I(inode)->flags;
+ /* swapfiles are not supposed to be shared */
+ if (IS_SWAPFILE(inode))
+ return 0;
+
rc = wait_on_bit_lock_action(flags, CIFS_INO_LOCK, cifs_wait_bit_killable,
TASK_KILLABLE);
if (rc)