f7fa3a5f77
Mounting disks that is remounted after restarts requires modifying /etc/fstab file, which is difficult to do in safe manner. - If multiple processes edit the file at the same time, we might lose updates or corrupt the file. Thus a lock needs to be taken. - If OS crashes while updating the file, we might corrupt the file. Thus the operation should be done atomically. - If device path or mount point is already in the /etc/fstab file it might cause unexpected behavior, so we should check their existence before adding the related line to /etc/fstab Since there are many potential pitfalls, we are adding an utility to safely add entries to /etc/fstab file.
30 lines
798 B
Ruby
Executable File
30 lines
798 B
Ruby
Executable File
#!/bin/env ruby
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# frozen_string_literal: true
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require "fileutils"
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require_relative "../lib/util"
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if ARGV.count != 6
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fail "Wrong number of arguments. Expected 6, Given #{ARGV.count}"
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end
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device, dir, type, options, dump, fsck = ARGV
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File.open("/etc/fstab", File::RDONLY) do |f|
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f.flock(File::LOCK_EX)
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content = f.read
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rows = content.split("\n").reject { _1.start_with?("#") }
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matches = rows.select { _1.match(/\A#{device}\s|\s#{dir}\s/) }
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if matches.count == 0
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content += "\n#{device} #{dir} #{type} #{options} #{dump} #{fsck}"
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safe_write_to_file("/etc/fstab", content)
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break
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end
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if matches.count > 1 || matches.first !~ /\A#{device}\s#{dir}\s#{type}\s#{options}\s#{dump}\s#{fsck}\z/
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fail "device path and/or mount point already exist in /etc/fstab"
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end
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end
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