Lustre
  1. Lustre
  2. LU-2869

extended attribute cache for Lustre

    Details

    • Type: Improvement Improvement
    • Status: Resolved
    • Priority: Minor Minor
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: Lustre 2.5.0
    • Labels:
    • Rank:
      6920

      Description

      The patch implements an extended attribute cache for
      a Lustre client. It is organized as a write-through
      cache: reads are performed from cache, updates are sent
      synchronously to the MDS. An additional inode bit
      is added to protect the cache.

      The patch itself will be uploaded shortly.

        Issue Links

          Activity

          Hide
          Alex Zhuravlev added a comment -

          well, if this failure is -ENOENT, then it should be easy to check and skip? on the otherhand we carry this structure for every object in MDT cache. a bit expensive for such a case?

          Show
          Alex Zhuravlev added a comment - well, if this failure is -ENOENT, then it should be easy to check and skip? on the otherhand we carry this structure for every object in MDT cache. a bit expensive for such a case?
          Hide
          Andrew Perepechko added a comment - - edited

          Besides -ENOENT, due to races an FLXATTRLS user can get an inconsistent list of attribute names and values, which the object never had from another client viewpoint. But since there is no use case for that, the locking can be simply dropped.

          Show
          Andrew Perepechko added a comment - - edited Besides -ENOENT, due to races an FLXATTRLS user can get an inconsistent list of attribute names and values, which the object never had from another client viewpoint. But since there is no use case for that, the locking can be simply dropped.
          Hide
          Alex Zhuravlev added a comment -

          not sure what kind of inconsistency FLXATTRLS can observe? any plans to make a patch to drop it?

          Show
          Alex Zhuravlev added a comment - not sure what kind of inconsistency FLXATTRLS can observe? any plans to make a patch to drop it?
          Hide
          Andrew Perepechko added a comment -

          not sure what kind of inconsistency FLXATTRLS can observe?

          Like, setxattr "a=x", setxattr "b=y". An unlocked FLXATTRLS can pack "b=y" update without packing "a=x" because of update races.

          any plans to make a patch to drop it?

          I'll update http://review.whamcloud.com/#/c/7208/ with this fix in a while.

          Show
          Andrew Perepechko added a comment - not sure what kind of inconsistency FLXATTRLS can observe? Like, setxattr "a=x", setxattr "b=y". An unlocked FLXATTRLS can pack "b=y" update without packing "a=x" because of update races. any plans to make a patch to drop it? I'll update http://review.whamcloud.com/#/c/7208/ with this fix in a while.
          Hide
          Alex Zhuravlev added a comment -

          great. thanks!

          Show
          Alex Zhuravlev added a comment - great. thanks!

            People

            • Assignee:
              James Nunez
              Reporter:
              Andrew Perepechko
            • Votes:
              0 Vote for this issue
              Watchers:
              9 Start watching this issue

              Dates

              • Created:
                Updated:
                Resolved: