From: Christoph Hellwig <hch@lst.de>
Date: Mon, 12 Dec 2022 07:37:22 +0000 (+0100)
Subject: btrfs: never return true for reads in btrfs_use_zone_append
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=fdf9a37dcfd47e9bd18d1218f2d0b2fa3748d00d;p=linux.git

btrfs: never return true for reads in btrfs_use_zone_append

Using Zone Append only makes sense for writes to the device, so check
that in btrfs_use_zone_append.  This avoids the possibility of
artificially limited read size on zoned file systems.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
---

diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c
index 8824748ee8c30..442bb79ffd082 100644
--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -1641,6 +1641,9 @@ bool btrfs_use_zone_append(struct btrfs_bio *bbio)
 	if (!is_data_inode(&inode->vfs_inode))
 		return false;
 
+	if (btrfs_op(&bbio->bio) != BTRFS_MAP_WRITE)
+		return false;
+
 	/*
 	 * Using REQ_OP_ZONE_APPNED for relocation can break assumptions on the
 	 * extent layout the relocation code has.