s_op->remount_fs() is only called from legacy_reconfigure(), which is not used after being converted to the new API.
Convert to using ->reconfigure(). This restores the previous behavior of syncing the filesystem and rejecting MS_MANDLOCK on remount.
Fixes: c30da2e981a7 ("fuse: convert to use the new mount API") Cc: stable@vger.kernel.org # v5.4 Signed-off-by: Miklos Szeredi mszeredi@redhat.com --- fs/fuse/inode.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 5b4aebf5821f..be39dff57c28 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -121,10 +121,12 @@ static void fuse_evict_inode(struct inode *inode) } }
-static int fuse_remount_fs(struct super_block *sb, int *flags, char *data) +static int fuse_reconfigure(struct fs_context *fc) { + struct super_block *sb = fc->root->d_sb; + sync_filesystem(sb); - if (*flags & SB_MANDLOCK) + if (fc->sb_flags & SB_MANDLOCK) return -EINVAL;
return 0; @@ -817,7 +819,6 @@ static const struct super_operations fuse_super_operations = { .evict_inode = fuse_evict_inode, .write_inode = fuse_write_inode, .drop_inode = generic_delete_inode, - .remount_fs = fuse_remount_fs, .put_super = fuse_put_super, .umount_begin = fuse_umount_begin, .statfs = fuse_statfs, @@ -1296,6 +1297,7 @@ static int fuse_get_tree(struct fs_context *fc) static const struct fs_context_operations fuse_context_ops = { .free = fuse_free_fc, .parse_param = fuse_parse_param, + .reconfigure = fuse_reconfigure, .get_tree = fuse_get_tree, };
The command
mount -o remount -o unknownoption /mnt/fuse
succeeds on kernel versions prior to v5.4 and fails on kernel version at or after. This is because fuse_parse_param() rejects any unrecognised options in case of FS_CONTEXT_FOR_RECONFIGURE, just as for FS_CONTEXT_FOR_MOUNT.
This causes a regression in case the fuse filesystem is in fstab, since remount sends all options found there to the kernel; even ones that are meant for the initial mount and are consumed by the userspace fuse server.
Fix this by ignoring mount options, just as fuse_remount_fs() did prior to the conversion to the new API.
Reported-by: Stefan Priebe s.priebe@profihost.ag Fixes: c30da2e981a7 ("fuse: convert to use the new mount API") Cc: stable@vger.kernel.org # v5.4 Signed-off-by: Miklos Szeredi mszeredi@redhat.com --- fs/fuse/inode.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index be39dff57c28..ba201bf5ffad 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -477,6 +477,13 @@ static int fuse_parse_param(struct fs_context *fc, struct fs_parameter *param) struct fuse_fs_context *ctx = fc->fs_private; int opt;
+ /* + * Ignore options coming from mount(MS_REMOUNT) for backward + * compatibility. + */ + if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) + return 0; + opt = fs_parse(fc, fuse_fs_parameters, param, &result); if (opt < 0) return opt;
Hi
[This is an automated email]
This commit has been processed because it contains a "Fixes:" tag fixing commit: c30da2e981a7 ("fuse: convert to use the new mount API").
The bot has tested the following trees: v5.7.8, v5.4.51.
v5.7.8: Build OK! v5.4.51: Failed to apply! Possible dependencies: 7f5d38141e309 ("new primitive: __fs_parse()") 82995cc6c5ae4 ("libceph, rbd, ceph: convert to use the new mount API") d7167b149943e ("fs_parse: fold fs_parameter_desc/fs_parameter_spec")
NOTE: The patch will not be queued to stable trees until it is upstream.
How should we proceed with this patch?
On Thu, Jul 16, 2020 at 2:27 AM Sasha Levin sashal@kernel.org wrote:
Hi
[This is an automated email]
This commit has been processed because it contains a "Fixes:" tag fixing commit: c30da2e981a7 ("fuse: convert to use the new mount API").
The bot has tested the following trees: v5.7.8, v5.4.51.
v5.7.8: Build OK! v5.4.51: Failed to apply! Possible dependencies: 7f5d38141e309 ("new primitive: __fs_parse()") 82995cc6c5ae4 ("libceph, rbd, ceph: convert to use the new mount API") d7167b149943e ("fs_parse: fold fs_parameter_desc/fs_parameter_spec")
NOTE: The patch will not be queued to stable trees until it is upstream.
How should we proceed with this patch?
Conflict resolution is trivial.
Thanks, Miklos
linux-stable-mirror@lists.linaro.org