[PATCH 5.10 017/157] zonefs: prevent use of seq files as swap file

Greg Kroah-Hartman
2021-03-22T12:41:24Z

From: Damien Le Moal <damien.lemoal@wdc.com>

commit 1601ea068b886da1f8f8d4e18b9403e9e24adef6 upstream.

The sequential write constraint of sequential zone file prevent their
use as swap files. Only allow conventional zone files to be used as swap
files.

Fixes: 8dcc1a9d90c1 ("fs: New zonefs file system")
Cc: <stable@vger.kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/zonefs/super.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

--- a/fs/zonefs/super.c
+++ b/fs/zonefs/super.c
@@ -159,6 +159,21 @@ static int zonefs_writepages(struct addr
return iomap_writepages(mapping, wbc, &wpc, &zonefs_writeback_ops);
}

+static int zonefs_swap_activate(struct swap_info_struct *sis,
+ struct file *swap_file, sector_t *span)
+{
+ struct inode *inode = file_inode(swap_file);
+ struct zonefs_inode_info *zi = ZONEFS_I(inode);
+
+ if (zi->i_ztype != ZONEFS_ZTYPE_CNV) {
+ zonefs_err(inode->i_sb,
+ "swap file: not a conventional zone file\n");
+ return -EINVAL;
+ }
+
+ return iomap_swapfile_activate(sis, swap_file, span, &zonefs_iomap_ops);
+}
+
static const struct address_space_operations zonefs_file_aops = {
.readpage = zonefs_readpage,
.readahead = zonefs_readahead,
@@ -171,6 +186,7 @@ static const struct address_space_operat
.is_partially_uptodate = iomap_is_partially_uptodate,
.error_remove_page = generic_error_remove_page,
.direct_IO = noop_direct_IO,
+ .swap_activate = zonefs_swap_activate,
};

static void zonefs_update_stats(struct inode *inode, loff_t new_isize)