5.10-stable review patch. If anyone has any objections, please let me know.
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From: Johannes Kimmel kernel@bareminimum.eu
commit dc08c58696f8555e4a802f1f23c894a330d80ab7 upstream.
Currently, displaying the btrfs subvol mount option doesn't escape ','. This makes parsing /proc/self/mounts and /proc/self/mountinfo ambiguous for subvolume names that contain commas. The text after the comma could be mistaken for another option (think "subvol=foo,ro", where ro is actually part of the subvolumes name).
Replace the manual escape characters list with a call to seq_show_option(). Thanks to Calvin Walton for suggesting this approach.
Fixes: c8d3fe028f64 ("Btrfs: show subvol= and subvolid= in /proc/mounts") CC: stable@vger.kernel.org # 5.4+ Suggested-by: Calvin Walton calvin.walton@kepstin.ca Signed-off-by: Johannes Kimmel kernel@bareminimum.eu Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/super.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -1502,8 +1502,7 @@ static int btrfs_show_options(struct seq subvol_name = btrfs_get_subvol_name_from_objectid(info, BTRFS_I(d_inode(dentry))->root->root_key.objectid); if (!IS_ERR(subvol_name)) { - seq_puts(seq, ",subvol="); - seq_escape(seq, subvol_name, " \t\n\"); + seq_show_option(seq, "subvol", subvol_name); kfree(subvol_name); } return 0;