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From:   Eric Van Hensbergen <ericvh@kernel.org>
Date:   Wed, 26 Apr 2023 16:30:35 +0000
Subject: [PATCH] fs/9p: Fix bit operation logic error
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Message-Id: <20230426-fix-bitops-v1-1-ab11e8f4f23a@kernel.org>
To:     Eric Van Hensbergen <ericvh@gmail.com>,
        Latchesar Ionkov <lucho@ionkov.net>,
        Dominique Martinet <asmadeus@codewreck.org>,
        Christian Schoenebeck <linux_oss@crudebyte.com>
Cc:     v9fs-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org,
        v9fs@lists.linux.dev,
        Christophe Jaillet <christophe.jaillet@wanadoo.fr>,
        Eric Van Hensbergen <ericvh@kernel.org>
Precedence: bulk

This re-introduces a fix that somehow got dropped during rebase of the
current series in for-next.  When writeback is enabled, opens
are forced to support both read and write operations but with the
logic error other flags may be dropped unintentionaly.

Reported-by: Christophe Jaillet <christophe.jaillet@wanadoo.fr>
Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
---
 fs/9p/vfs_inode.c      | 2 +-
 fs/9p/vfs_inode_dotl.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c
index 54dfe4f10f43..3791f642c502 100644
--- a/fs/9p/vfs_inode.c
+++ b/fs/9p/vfs_inode.c
@@ -823,7 +823,7 @@ v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
 	p9_omode = v9fs_uflags2omode(flags, v9fs_proto_dotu(v9ses));
 
 	if ((v9ses->cache & CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) {
-		p9_omode = (p9_omode & !P9_OWRITE) | P9_ORDWR;
+		p9_omode = (p9_omode & ~P9_OWRITE) | P9_ORDWR;
 		p9_debug(P9_DEBUG_CACHE,
 			"write-only file with writeback enabled, creating w/ O_RDWR\n");
 	}
diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c
index f9371b5b70ea..3acf2bcb69cc 100644
--- a/fs/9p/vfs_inode_dotl.c
+++ b/fs/9p/vfs_inode_dotl.c
@@ -288,7 +288,7 @@ v9fs_vfs_atomic_open_dotl(struct inode *dir, struct dentry *dentry,
 	}
 
 	if ((v9ses->cache & CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) {
-		p9_omode = (p9_omode & !P9_OWRITE) | P9_ORDWR;
+		p9_omode = (p9_omode & ~P9_OWRITE) | P9_ORDWR;
 		p9_debug(P9_DEBUG_CACHE,
 			"write-only file with writeback enabled, creating w/ O_RDWR\n");
 	}

---
base-commit: 4eb3117888a923f6b9b1ad2dd093641c49a63ae5
change-id: 20230426-fix-bitops-c862099c8d28

Best regards,
-- 
Eric Van Hensbergen <ericvh@kernel.org>