** Description changed:

  [Impact]
- The shell's read builtin iterates through /proc/mounts one byte at a time. 
This becomes problematic when LDAP automount maps generate a large number of 
entries in /proc/mounts. It can lead to timeout issues, especially when 
iterating through the entries twice in the cryptroot hook.
+ The shell's read builtin iterates through /proc/mounts one line at a time. 
This becomes problematic when LDAP automount maps generate a large number of 
entries in /proc/mounts. It can lead to timeout issues, especially when 
iterating through the entries twice in the cryptroot hook.
  
  [Fix]
  Applying the following upstream commit [1] can resolve this issue.
  
  95fd4be9b4c6 d/functions: get_mnt_devno(): Speed up execution time on large 
/proc/mounts.
      Use awk rather than a `while read; do done` loop here as the /proc/mounts
      pseudo-file can be many thousands lines long and the shell's `read` 
builtin
      traverses it one read(2) at the time which cruelly slows down execution 
time.
  
      See https://salsa.debian.org/cryptsetup-
  team/cryptsetup/-/merge_requests/36 .
  
  [1] https://salsa.debian.org/cryptsetup-
  team/cryptsetup/-/commit/95fd4be9b4c6471e94c418101e7acfae7e1aa4fc
  
  [Test Plan]
  (SRU team: pending changes in comment #25)
  Our primary objective is to ensure that the output remains consistent when 
obtaining devnos through iteration.
  1. Execute the /usr/share/initramfs-tools/hooks/cryptroot binary
  2. Confirm that the output does not include the following warning message:
  cryptsetup: WARNING: Couldn't determine root device
  
  [Where problems could occur]
  The patch exclusively modifies the method of extracting information without 
altering the underlying hook logic.
  It's crucial to note that the successful generation of the crypttab is 
contingent upon the accuracy of the information provided by the patch.
  Any inaccuracies may impede the crypttab generation process.
  
  [Other Info]
  The proposed change [1] is already applied in Oracular and Plucky.

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https://bugs.launchpad.net/bugs/2054390

Title:
  Refine proc mounts entries traversal

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